CGGC Seminar: Hierarchical Volumetric Modeling as a Base for Multiscale Physical Based Analysis and Design of Porous Structures

Lev Podshivalov (Pierre-and-Marie-Curie University, Paris, France)

Sunday, 30.12.2012, 13:00

Room 337-8 Taub Bld.

Hierarchical modeling is often applied in fields such as computer vision, computer graphics, computer-aided geometric design, cartography and virtual reality. The importance of this approach has increased in recent years due to the ability to create models with more details. Hierarchical modeling is useful in order to make storage, transmission, computation, and visualization of these models possible and more efficient. The most prevalent 3D hierarchical geometric data structure i...

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Theory Seminar: Distributed Computing Meets Biology: Towards a New Scientific Framework

Amos Korman (University of Paris Diderot)

Wednesday, 26.12.2012, 12:30

Taub 201

In recent years, several works have demonstrated how the
study of biology can benefit from an algorithmic perspective. In this
talk I discuss a new approach for such a methodology based on
combining theoretical tradeoff techniques with field experiments to
obtain bounds on biological parameters. A proof of concept for this
framework is provided by considering central search foraging
strategies of desert ants, and obtaining theoretical tradeoffs between
the search time and t...

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TCE Guest Lecture: Energy-Aware Scheduling for Heterogeneous Multi-Core Architectures

Daniel Mossé (University of Pittsburgh)

Wednesday, 26.12.2012, 11:30

EE Meyer Building 861

The current trend to move from homogeneous to heterogeneous multi-core (HetCMP) systems promises further performance and energy-efficiency benefits. A typical HetCMP system includes two distinct types of cores, such as high performance sophisticated ("large") cores and simple low-power ("small") cores. In those heterogeneous platforms, execution phases of application threads that are CPU-intensive can take best advantage of large cores, whereas I/O or memory intensive execution ph...

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Pixel Club: From the invention of Compressive Sensing to Recent Results

Yoram Bresler (University of Illinois, Urbana-Champaign)

Tuesday, 25.12.2012, 13:30

EE Meyer Building 861

Compressive sensing (CS), also known as compressive sampling, has become widely
popular in recent years. In the first part of the talk, we review the little
known fact, that the invention of CS preceded the papers that popularized it by
almost a decade. Spectrum-blind sampling (SBS), proposed by Bresler and Feng in
the mid-90’s, and further developed into “image compression on the fly,” with
Venkataramani, and Gastpar, is the first known compressed sensing technique.
T...

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Pixel Club: Sparse Matrix Models for Finding Good Data Representatives and Constraining
the Topology of Networks

Guillermo Sapiro (Duke University)

Tuesday, 25.12.2012, 11:30

EE Meyer Building 1003

We consider the problem of finding a few representatives for a dataset,
i.e., a subset of data points that efficiently describes the entire dataset.
We assume that each data point can be expressed as a linear combination of
the representatives and formulate the problem of finding the representatives
as a sparse multiple measurement vector problem. In our formulation, both
the dictionary and the measurements are given by the data matrix, and the
unknown sparse codes select th...

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Haifux Club: Learning from the Open Source Production Process

Yael Vaya-Talmor (Bar-Ilan University)

Monday, 24.12.2012, 18:30

Taub 6

The open source production process is fascinating in many respects: it produces high quality code outside the boundaries of the hierarchical organization, it defies the rules of many traditional software production models and it has many profound implications on social, political, and economic systems of the Internet era.
I will discuss prior research work on the topic. For example, should open source serve as an example of how to develop systems of participation w...

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Exploring Human Evolution and Deciphering the Human Genome Using Complete Individual Genome Sequences

Ilan Gronau

Monday, 24.12.2012, 14:30

Room 337-8 Taub Bld.

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CSL Lucnheon: Real-Time Systems Scheduling for Energy Optimization

Gil Kedar

Thursday, 20.12.2012, 12:30

Classroom 9 Taub Bld.

Advisor-Avi Mendelson.Embedded real-time systems are continuously required to increase performance and to reduce power and energy consumption. Higher performance is needed in order to meet new demand of emerging applications. In order to meet such performance demand, modern processors implement complex enhancement mechanisms such as deeper pipeline, vector units, multi-cores and more. In real-time systems, energy consumption can be saved as long as the system guarantees meetin...

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Generating Map-based Routes from GPS Trajectories and their Compact Representation

Ranit Gotsman

Wednesday, 19.12.2012, 13:00

Taub 601

Digital maps and devices with an integrated GPS receiver, such as smartphones, are now an integral part of our lives.
We deal with two practical problems related to GPS trajectories and digital maps.
The first problem is the classical problem of map-matching; namely, matching a given GPS trajectory,
possibly noisy or sparse, to the sequence of actual roads traversed by the carrier of the GPS receiver.
We provide a novel solution to this problem. Our algorithm is adapted to w...

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Theory Seminar: New Applications of Communication Complexity in Distributed Computing

Rotem Oshman (University of Toronto)

Wednesday, 19.12.2012, 12:45

Taub 201

The advent of large-scale wireless networks has presented the distributed computing community with a new challenge: wireless networks are much more disorderly than traditional wired networks, and they are difficult to model and predict. In addition, they are subject to different design considerations: among other criteria, it is crucial to conserve power by reducing the amount of communication between network nodes. This communication constraint leads to interesting connections be...

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ceClub: Predicting Execution Bottlenecks in Map-Reduce Clusters

Edward Bortnikov (Yahoo! Labs Israel)

Wednesday, 19.12.2012, 11:30

EE Meyer Building 861

Extremely slow, or straggler, tasks are a major performance bottleneck in map-reduce systems. Hadoop infrastructure makes an effort to both avoid them (through minimizing remote data accesses) and handle them in the runtime (through speculative execution). However, the mechanisms in place neither guarantee the avoidance of performance hotspots in task scheduling, nor provide any easy way to tune the timely detection of stragglers.
We suggest a machine-learning approach...

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Operating system support for high-throughput processors

Mark Silberstein

Tuesday, 18.12.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Hybrid Classifiers for Object Classification with a Rich Background

Margarita Osadchy (Computer Science, Haifa University)

Tuesday, 18.12.2012, 11:30

EE Meyer Building 1061

The majority of current methods in object classification use the
one-against-rest training scheme. We argue that when applied to a
large number of classes, this strategy is problematic: as the
number of classes increases, the negative class becomes a very
large and complicated collection of images. The resulting
classification problem then becomes extremely unbalanced, and
kernel SVM classifiers trained on such sets require long training
time and are slow in prediction. ...

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TCE Guest Lecture: Multimodal First-Person Perception

Denver Dash (Intel – ISTC for Embedded Computing)

Thursday, 13.12.2012, 13:30

EE Meyer Building 1061

For decades, our culture has been fascinated with the concept of the “Star Trek computer”. An all-knowing entity which is available to query about almost anything relevant to the world around us, organize our daily lives, remind us when we are doing the wrong thing, help us when we are lost. Several key features of this type of system are: (1) We can interact with it via natural language and it will understand our words (speech2text), (2) it will understand what we want to kno...

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CSL Lucnheon: An Advertising Mechanism for P2P Networks

Alex Libov

Thursday, 13.12.2012, 12:30

Room 337-8 Taub Bld.

Advisor-Roy Friedman.In order for P2P systems to be viable, users must be given
incentives to donate resources. Such incentives can be in the form
of tit-for-tat like mechanisms, in which a user is rewarded with
better service for contributing resources to the system.
Alternatively, such incentives can be economical, i.e., users get
paid for their contribution. In particular, the latter can be
achieved through a P2P advertisement mechanism. We believe that
P2P advertisement me...

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Fair is Fair: A Protocol and an Algorithm for Unbiased Evaluation of Linguistic Structure Prediction.

Reut Tsarfaty

Wednesday, 12.12.2012, 14:30

Room 337-8 Taub Bld.

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Learning patterns in Big data from small data using core-sets

Dan Feldman

Tuesday, 11.12.2012, 14:30

Room 337-8 Taub Bld.

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TCE Guest Lecture: Unconventional Fault-tolerant Accelerators

Olivier Temam (INRIA)

Thursday, 06.12.2012, 12:30

EE Meyer Building 861

Due to the evolution of technology constraints, especially energy constraints which may lead to heterogeneous multicores, and the increasing number of transient faults and permanent defects, the design of defect-tolerant accelerators for heterogeneous multi-cores may become a major micro-architecture research issue.
Most custom circuits are highly defect sensitive, a single transistor can wreck such circuits. On the contrary, neural networks (NNs) are inherently error-t...

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Syntactic Annotation of Hebrew CHILDES Corpora

Avishay Gretz

Wednesday, 05.12.2012, 12:30

Taub 601

The CHILDES database is a large collection of child---adult spoken interactions in over 25 languages.
Automatic annotation of these data faciliates research on child language
development and acquisition by providing researchers with a large amount
of accurate data. Recently, the English section of the CHILDES database was
automatically annotated with labeled dependency relations in a state-of-the-art approach.
We describe a similar endeavor, focusing on the Hebrew section of CHIL...

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Theory Seminar: Sealed Bid Combinatorial Auctions

Shahar Dobzinski (Weizmann Institute of Science)

Wednesday, 05.12.2012, 12:30

Taub 201

We generalize sealed bid auctions to accommodate combinatorial
auctions. In a sealed bid combinatorial auction each bidder sends to
the auctioneer, simultaneously with the others, a message that depends
only on his own valuation. The auctioneer decides on the allocation
based on these messages alone. The goal is to find an allocation of
the items which maximizes the social welfare. In this simultaneous
communication complexity model we ask: How much information each of
the ...

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CGGC Seminar: Computing Extremal Quasiconformal Maps

Ofir Weber (Computer Science, Haifa University)

Wednesday, 05.12.2012, 11:30

Taub 401

Conformal maps are widely used in geometry processing applications. They are smooth, preserve angles, and are locally injective by construction. However, conformal maps do not allow for boundary positions to be prescribed. A natural extension to the space of conformal maps is the richer space of quasiconformal maps of bounded conformal distortion. Extremal quasiconformal maps, that is, maps minimizing the maximal conformal distortion, have a number of appealing properties making t...

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Pixel Club: Photo Sequencing

Yael Moses (CS, The Interdisciplinary Center, Herzliya)

Tuesday, 04.12.2012, 11:30

EE Meyer Building 1061

Dynamic events such as family gatherings, concerts or sports events are
often captured by a group of people. The set of still images obtained this
way is rich in dynamic content but lacks accurate temporal information. We
propose a method for *photo-sequencing* -- temporally ordering a set of
still images taken asynchronously by a set of uncalibrated cameras.
Photo-sequencing is an essential tool in analyzing (or visualizing) a
dynamic scene captured by still images.
...

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Haifux Club: The Device Tree: Plug and play for Embedded Linux

Eli Billauer

Monday, 03.12.2012, 18:30

Taub 6

On embedded systems, the Linux kernel doesn't have the BIOS to tell it what the hardware is like. On the other hand, the traditional solution of having the hardware information hardcoded in the kernel source is leading to an overpopulation of platform-specific hacks (read: a disaster).
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TCE Guest Lecture: How Alan Turing Cracked the Enigma Code

Ymir Vigfusson (Reykjavik University)

Monday, 03.12.2012, 13:30

Room 337-8 Taub Bld.

Code breakers played an enormously crucial role in World War II. Alan Turing, the father of computer science, was at the center of allied code breaking operations and his breakthroughs made intelligence gathering not only possible but practical. This general audience talk, celebrating Alan Turing's Centenary, explains the notorious German Enigma code and how it was systematically cracked by the Allies.
Bio
Ymir Vigfusson is an Assistant Professor at the School of C...

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CGGC Seminar: Accelerating Geometric Operations on Freeform Models

Yong Joon Kim (Computer Science, Technion)

Sunday, 02.12.2012, 13:00

Room 337-8 Taub Bld.

NURBS is one of the typical way of representing geometric data and have been widely used in many areas such as computer graphics, CAGD, robotics. NURBS represents geometric data based on the mathematical form, and thus it requires relatively small memory space compared to the other representations. Compactness of geometric data is crucial in recent computing environments (Network, Mobile, Multi-Core) and NURBS is good candidate to be a geometric representation in such environments...

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Bioinformatics Forum: Fragment-Based Design of RNA sequences and Detection of RNA switches

Danny Barash (CS, Ben-Gurion University)

Thursday, 29.11.2012, 13:30

Taub 701

The inverse RNA folding problem for designing sequences that fold into a
given RNA secondary structure was introduced in the early 1990's in Vienna.
Using a coarse-grain tree graph representation of the RNA secondary structure,
we extended the inverse RNA folding problem to include constraints such as
thermodynamic stability and mutational robustness, deveoping a program called
RNAexinv. Furthermore, we propose a fragment-based design approach of RNA
sequences that can be u...

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Theory Seminar: Partially Symmetric Functions are Efficiently Isomorphism-Testable

Amit Weinstein (Tel-Aviv University)

Wednesday, 28.11.2012, 12:30

Taub 201

Given a function f: {0,1}^n \to {0,1}, the f-isomorphism testing problem requires a randomized algorithm to distinguish functions that are identical to f up to relabeling of the input variables from functions that are far from being so. An important open question in property testing is to determine for which functions f we can test f-isomorphism with a constant number of queries. Despite much recent attention to this question, essentially only two classes of functions were known t...

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ceClub: Optimal Rebuilding in Distributed Storage Systems

Zhiying Wang (Caltech)

Wednesday, 28.11.2012, 11:30

EE Meyer Building 861

Distributed storage systems have become a popular solution to large file storage and fast data access. In such systems, erasure-correcting codes are widely used to combat disk failures, where disks correspond to symbols in the code. Specifically, we study MDS (maximum distance separable) array codes which enable optimal storage and efficient encoding and decoding algorithms. With r redundancy symbols an MDS code can sustain r erasures. For example, consider an MDS code that can co...

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Pixel Club: Extracting Foreground Masks towards Object Recognition

Amir Rosenfeld (Weizmann Institute of Science)

Tuesday, 27.11.2012, 11:30

EE Meyer Building 1061

Effective segmentation prior to recognition has been shown to improve recognition performance. However, most segmentation algorithms
adopt methods which are not explicitly linked to the goal of object
recognition. Here we solve a related but slightly different problem in
order to assist object recognition more directly - the extraction of
a foreground ask, which identifies the locations of objects in the image.
We propose a novel foreground/background segmentation algorithm ...

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TCE Guest Lecture: Faults: a Foe or Friend?

Prof. Yanos Sazeides (University of Cyprus)

Tuesday, 27.11.2012, 10:00

EE Meyer Building 1061

The traditional performance-cost benefits enjoyed for decades from scaling of device area are challenged by the slowdown of voltage scaling and less reliable silicon primitives. These developments lead to pessimistic projections that it will be impossible to operate all on-chip resources, even at the minimum voltage for safe operation, due to power constraints, and the growing design and operational margins, used to provide silicon primitives with resiliency against variations, wi...

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Compiler, Architecture and Tools Conference

various speakers

Monday, 26.11.2012, 08:00

Intel Development Center, Haifa, Israel

The interaction between advanced compilation techniques, modern processor architectures, and associated tools continues to face new challenges and opportunities. Traditional demands to increase performance, reduce power consumption, and reduce time to market now apply to heterogeneous, virtualized and diverse user-experience environments. New programming environments such as OpenCL and C++ AMP enable programmers to better leverage data and task level parallelism, relying on effect...

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CSL Lucnheon: On the Programmability of OpenCL

Dr. Ana Lucia Varbanescu

Sunday, 25.11.2012, 12:30

Room 337-8 Taub Bld.

Nowadays, multi- and many-core architectures are becoming the focus of affordable High Performance Computing (HPC).
In this context, one of the programming models (and paradigms) that rapidly gains popularity is OpenCL, originally
designed and developed to exploit heterogeneous (massive) parallelism.
In this talk, I will briefly introduce our directions of research involving OpenCL, many-core architectures, and HPC,
and ranging from low-level memory access patterns analysis to...

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Fractional Secret Sharing and Lossy Chains

Omer Strulovich

Wednesday, 21.11.2012, 15:30

Taub 601

A rich man has many children. Unfortunately, over the years they have grew
apart and started to hate each other. The rich man seeks to
give his inheritance to the largest group of his children that can cooperate.
How can he do it?
To answer this, we introduce and study the related notions
of lossy chains and fractional secret sharing.
Both of these concepts are motivated by goal of controlling the amount of
work required in order to solve a cryptographic puzzle, or access a share...

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Joint Scheduling in Wireless Networks

Guy Grebla

Wednesday, 21.11.2012, 14:00

Taub 601

A crucial step in the evolution of broadband
wireless (cellular) networks is reducing the size of the cells
and increasing their number. This target is usually obtained
using cell sectorization, where the omni-directional antenna
at each base station (BS) is replaced by 3 or 6 directional
antennas. With respect to this evolution, the contribution
of our work is two-fold. First, we propose a new protocol
stack for a BS that governs multiple directional antennas.
In the new stack th...

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Theory Seminar: From the Impossibility of Obfuscation to a New Non-Black-Box Technique

Nir Bitansky (Tel-Aviv University)

Wednesday, 21.11.2012, 12:30

Taub 201

The introduction of a non-black-box simulation technique by Barak (FOCS 2001) has been a major landmark in cryptography, breaking the previous barriers of black-box impossibility. Barak’s techniques were subsequently extended and have given rise to various powerful applications. We present the first non-black-box simulation technique that does not rely on Barak’s technique. Our technique is based on essentially different tools: it does not invoke universal arguments, nor does...

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ceClub: CBTree: A Practical Concurrent Self-Adjusting Search Tree

Adam Morrison (CS, Tel Aviv University)

Wednesday, 21.11.2012, 11:30

Room 337-8 Taub Bld.

We present the CBTree, a new counting-based self-adjusting sequential search tree that, like splay trees, moves more frequently accessed nodes closer to the root: After M operations on N items, Q of which access some item V, an operation on V traverses a path of length O(log M/Q) while performing few if any rotations.
In contrast to the traditional self-adjusting splay tree in which each accessed item is moved to the root through a sequence of tree rotations, the CBTree...

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Querying Web Applications Under Terms of Uncertainty

Daniel Deutch

Tuesday, 20.11.2012, 14:30

Room 337-8 Taub Bld.

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Geometric Covering

Nadav Shragai

Sunday, 18.11.2012, 13:00

Taub 337

Covering questions emerges in many disciplines and are closely related to the
well known set-cover problem in computer science. Similarly, geometric covering
is of great importance and yet has only been investigated in seemingly unrelated
specific disciplines. Examples include the well known art-gallery problem,
mold-design problems, inspection, security and surveillance problems.
In this thesis, we present a single unified framework that can solve many of
the above geometric c...

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Large Scale Semi-Supervised Sentiment Analysis

Yoav Haimovitch

Wednesday, 14.11.2012, 12:30

Taub 601

We describe a bootstrapping algorithm able to learn from partially labeled data.
We report the results of an empirical study for using this algorithm to improve performance of sentiment classification using up to 15 million unlabeled Amazon product reviews. Our experiments cover semi-supervised learning, domain adaptation and weakly supervised learning. In some cases our methods were able to reduce test error by more than half using such large amounts of data, and in all cases a s...

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Theory Seminar: Predecessor Queries on Dynamic Subsets of an Ordered List, with Applications

Tsvi Kopelowitz (Weizmann Institute of Science)

Wednesday, 14.11.2012, 12:30

Taub 201

In the famous order maintenance problem, one wishes to maintain a dynamic list L of size n under insertions, deletions, and order queries. In an order query, one is given two nodes from L and must determine which node precedes the other in L. In an extension to this problem, named the
Predecessor search on Dynamic Subsets of an Ordered Dynamic List problem (POLP for short), it is also necessary to maintain dynamic subsets S_1... S_k \subset L, such that given some u in L it will ...

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Backward causality in temporal Talmudic logic

Dov Gabbay

Tuesday, 13.11.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Non-Rigid Shape Correspondence Using Sparsity

Michael Bronstein (University of Lugano, Switzerland)

Tuesday, 13.11.2012, 11:30

EE Meyer Building 1003

Finding dense intrinsic correspondence between non-rigid shapes is a
notoriously difficult problem with many important applications in computer
graphics and pattern recognition.
In the first part of the talk, I will present a novel sparse modeling
approach to non-rigid shape matching using only the ability to detect
repeatable regions. As the input to our algorithm, we are given only two
sets of regions in two shapes; no descriptors are provided so the
corresponde...

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IBM Programming Languages and Software Engineering (PLSE) Seminar 2012

various speakers

Monday, 12.11.2012, 09:00

IBM Research - Haifa, Israel

This year we are honored to host Prof. David Parnas, who will give the main keynote on "Software Development – What's Missing?" Prof. Parnas, along with Prof. David Harel and others, will also participate in a panel discussion titled "Fixing Software Engineering," moderated by Prof. Amiram Yehudai. Prof. Parnas' talk at the seminar will be the first in a series of unique lectures in Israel....

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Fast Parallel Matrix Multiplication

Oded Schwartz

Sunday, 11.11.2012, 14:30

Room 337-8 Taub Bld.

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On the Role of Color Information in Texture Recognition

Micha Kalfon

Sunday, 11.11.2012, 11:30

Taub 601

Texture features have always been a key attribute in image recognition and
classification. In this work we propose a pre-processing stage for enhancing
the performance of widely used color texture recognition methods. One approach
we investigated, Decorrelation Stretching, was employed historically for
enhancing the interpretability of multi-channel satellite images. This is
achieved by stretching the dynamic range of color data over its principal
components. Another approach deco...

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Taming Logics: Theory, Tools, Applications

Anna Zamansky

Wednesday, 07.11.2012, 14:30

Room 337-8 Taub Bld.

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Asymptotic and Numerical Solution for Electrokinetic Flow Around a Spherical Particle

Roman Zeyde

Wednesday, 07.11.2012, 12:30

Taub 601

A numerical framework for the simulation of electrokinetic migration of
particles in an electrolyte solution due to the application of an external
electric field is presented.
The electrokinetic transport process is described by a system of nonlinear
partial differential equations (PDE). A thin boundary layer forms around
the particle due to strong electrostatic forces. The resulting scale disparity
of the boundary layer is used to derive nonlinear effective boundary conditio...

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Theory Seminar: On Sunflowers and Matrix Multiplication

Leonid Barenboim (Ben-Gurion University)

Wednesday, 07.11.2012, 12:30

Taub 201

In a distributed message passing model a communication network is represented by an n-vertex graph whose vertices host processors, and edges serve as communication links. One of the most fundamental goals in this setting is breaking the symmetry in the network. Specifically, the tasks of computing vertex coloring, maximal matching, and maximal independent set are of great importance. In the mid-eighties several randomized distributed algorithms for these problems were devised. [L...

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ceClub: The Future of the Telecommunication Industry: The New Horizon of Virtual Telecommunication and Carrier Clouds

David Amzallag (Alcatel-Lucent)

Wednesday, 07.11.2012, 11:30

Room 337-8 Taub Bld.

Wireless networks are the most important assets in our industry, yet the problem is that we are building new networks the same way we built our previous networks. Capacity is planned in advance per service; to handle peek traffic and to add new capacity takes time and investment of dedicated equipment. We have no elasticity as demand grows, on average the service is grossly underutilized though also over utilized at specific times of day or geographic locations, and we can't share...

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SSDL Seminar: On Incomplete Bug Fixes in Eclipse and Programmers Intuition on These

Sabih Agbaria (CS, Technion)

Tuesday, 06.11.2012, 12:30

Taub 235

Recent studies indicate that multiple patches to software are found in a hefty portion of resolved bugs.
It is also known that bugs that require multiple patches take longer to resolve, that their severity tends
to be higher than the average and that they induce programmers to engage more in bug discussions.
This work is concerned with the ability of programmers to predict a bug will be of this sort, and in particular
that it may require future patches and great...

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TCE Guest Lecture: Optimized Networked Systems

Ymir Vigfusson (Reykjavik University)

Monday, 05.11.2012, 13:30

EE Meyer Building 861

Optimal use of computing resources is pivotal to minimize expenditures and improve competitiveness of companies. The computing technologies are continuously evolving and the users are adapting at a unparalleled pace, thus producing intriguing research questions.
In the first half of the talk, we observe that Internet service providers (ISPs) face surging Internet loads associated with real-time streaming video and various forms of dynamically generated, short-lived cont...

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Pixel Club: Computational Reconstruction of Zebra-Fish Early Embryogenesis by Nonlinear Pde Methods of Image Processing

Prof. Karol Mikula (Department of Mathematics, Slovak University of Technology, Bratislava, Slovakia)

Thursday, 01.11.2012, 12:30

Room 337-8 Taub Bld.

In the talk we present mathematical models and numerical methods
which lead to early embryogenesis reconstruction and extraction of the cell
lineage tree from the large-scale 4D image sequences. Robust and efficient
finite volume schemes for solving nonlinear PDEs related to filtering,
object detection and segmentation of 3D images were designed to that goal
and studied mathematically.
They were parallelized for massively parallel computer clusters and applied
to ...

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Theory Seminar: Constructive Discrepancy Minimization by Walking on The Wedges

Shachar Lovett (Institute for Advanced Study, Princeton)

Wednesday, 31.10.2012, 12:30

Taub 201

Minimizing the discrepancy of a set system is a fundamental problem in combinatorics. One of the cornerstones in this area is the celebrated six standard deviations result of Spencer (AMS 1985): In any system of $n$ sets in a universe of size $n$, there always exists a coloring which achieves discrepancy $6\sqrt{n}$. The original proof of Spencer was existential in nature, and did not give an efficient algorithm to find such a coloring. Recently, a breakthrough work of Bansal (FOC...

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TOWARDS A PROOF THEORY OF ANALOGICAL REASONING

Matthias Baaz

Tuesday, 30.10.2012, 14:30

Room 337-8 Taub Bld.

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ceClub: Self-Optimizing Microprocessors: A Machine Learning Approach

Jose F. Martinez (Cornell University)

Tuesday, 30.10.2012, 13:30

EE Meyer Building 861

As each technology generation brings additional transistors, the computer industry hopes to convert these into performance growth by stamping out a greater number of cores on a die. On the one hand, in many environments, that seems like a lot of hope. On the other hand, architecture researchers have grown almost allergic to "complex" alternatives, which history has shown can quickly fall off the cliff of diminishing returns.
A fundamental hurdle to bettering architectu...

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TCE Guest Lecture: Self-Optimizing Microprocessors: A Machine Learning Approach

José F. Martínez (Cornell University)

Tuesday, 30.10.2012, 13:30

EE Meyer Building 861

As each technology generation brings additional transistors, the computer industry hopes to convert these into performance growth by stamping out a greater number of cores on a die. On the one hand, in many environments, that seems like a lot of hope. On the other hand, architecture researchers have grown almost allergic to "complex" alternatives, which history has shown can quickly fall off the cliff of diminishing returns.
A fundamental hurdle to bettering architectur...

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Haifux Club: Israeli Digital Rights NPO

Zvi Devir (digitalrights.org.il)

Monday, 29.10.2012, 18:30

Taub 6

The Digital Rights Movement stands between advanced technology and people rights (in the broad sense). Technological advance provides us with new products and new means of interacting with our surrounding. It provides a customer more flexibility and new ways of using a given product. However, it can be used to control and limit the usability of the product. For example, a customer buys a product, a certain book. Does it matters if the product is a digital book or an old-fashioned ...

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Theory Seminar: On Sunflowers and Matrix Multiplication

Amir Shpilka (CS, Technion)

Wednesday, 24.10.2012, 12:30

Taub 201

We present several variants of the sunflower conjecture of Erdos and Rado and discuss the relations among them. We then show that two of these conjectures (if true) imply negative answers to questions of Coppersmith and Winograd and of Cohn et al regarding possible approaches for obtaining fast matrix multiplication algorithms. Specifically, we show that the Erdos-Rado sunflower conjecture (if true) implies a negative answer to the ``no three disjoint equivoluminous subsets'' ques...

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SSDL Seminar: Speculative Separation for Privatization and Reductions

Ayal Zaks (Intel)

Tuesday, 23.10.2012, 12:30

Taub 235

Automatic parallelization is a promising strategy to improve application performance in the multicore era. However, common programming practices such as the reuse of data structures introduce artificial constraints that obstruct automatic parallelization. Privatization relieves these constraints by replicating data structures, thus enabling scalable parallelization. Prior privatization schemes are limited to arrays and scalar variables because they are sensitive to the layout of d...

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Theory Seminar: Statistical Algorithms and a Lower Bound for Planted Clique

Vitaly Feldman (IBM Research Almaden)

Wednesday, 17.10.2012, 12:30

Taub 201

We develop a framework for proving lower bounds on computational
problems over distributions, including optimization and unsupervised learning. Our framework is based
on defining a restricted class of algorithms, called statistical algorithms, that instead of
accessing samples from the input distribution can
only obtain an estimate of the expectation of any given function on a
sample drawn randomly from the input distribution.
Our definition captures many natura...

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Haifux Club: Adding Colors To Kademlia

Gil Einziger (CS, Technion)

Monday, 15.10.2012, 18:30

Taub 6

Kademlia is considered to be one of the most effective key based routing protocols. It is nowadays implemented in many file sharing peer-to-peer networks such as BitTorrent, KAD, and Gnutella. Kaleidoscope , a novel routing/caching scheme designed to significantly reduce the cost of Kademlia lookup operations Kaleidoscope also improves the anonymity of nodes in the system....

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Learning to Predict the Future using Web Knowledge and Dynamics

Kira Radinsky

Tuesday, 09.10.2012, 16:30

Taub 601

Mark Twain famously said that ``the past does not repeat itself, but it rhymes.''
In the spirit of this reflection, we present novel algorithms and methods for leveraging large-scale
digital histories and human knowledge mined from the Web to make real-time predictions about the likelihoods
of future human and natural events of interest.
The Web is a dynamic being, with constantly updating content, which is entangled with sophisticated user behaviors and interactions.
Some o...

[ Full version ]

[ Full version ]

Learning to Predict the Future using Web Knowledge and Dynamics

Kira Radinsky

Tuesday, 09.10.2012, 16:30

Taub 601

Mark Twain famously said that ``the past does not repeat itself, but it rhymes.''
In the spirit of this reflection, we present novel algorithms and methods for leveraging large-scale
digital histories and human knowledge mined from the Web to make real-time predictions about the likelihoods
of future human and natural events of interest.
The Web is a dynamic being, with constantly updating content, which is entangled with sophisticated user behaviors and interactions.
Some o...

[ Full version ]

[ Full version ]

Learning to Predict the Future using Web Knowledge and Dynamics

Kira Radinsky

Tuesday, 09.10.2012, 16:30

Taub 601

Mark Twain famously said that ``the past does not repeat itself, but it rhymes.''
In the spirit of this reflection, we present novel algorithms and methods for leveraging large-scale
digital histories and human knowledge mined from the Web to make real-time predictions about the likelihoods
of future human and natural events of interest.
The Web is a dynamic being, with constantly updating content, which is entangled with sophisticated user behaviors and interactions.
Some o...

[ Full version ]

[ Full version ]

Learning to Predict the Future using Web Knowledge and Dynamics

Kira Radinsky

Tuesday, 09.10.2012, 16:30

Taub 601

[ Full version ]

Learning to Predict the Future using Web Knowledge and Dynamics

Kira Radinsky

Tuesday, 09.10.2012, 16:30

Taub 601

[ Full version ]

The Use of Overloading in Java Programs

Keren Lenz

Wednesday, 19.09.2012, 13:00

Taub 601

Method overloading is a controversial language feature, especially in the
context of Object Oriented languages, where its interaction with overriding
may lead to confusing semantics. One of the main arguments against overloading
is that it can be abused by assigning the same identity to conceptually
different methods.
This talk describes a study of the actual use of overloading in Java.
To this end, we developed a taxonomy of classification of the use of overloading,
and applie...

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Pixel Club: The Noise Clinic

Jean Michel Morel (CMLA, Ecole Normale Supereure de Cachan, France)

Wednesday, 19.09.2012, 11:30

Room 337-8 Taub Bld.

All images have noise, but this noise may have undergone many distortions. Can we take any image, say, an olde photograph, and denoise it? This requires a good denoising method and an accurate noise estimator, both working for "any" image and "any" noise. I'll discuss both aspects, and particularly how to estimate a signal-dependent and scale-dependent noise.
A prototype of the noise clinic is currently on line at http://dev.ipol.im/~colom/ipol_demo/noise_clinic/
(...

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Parameterizing P: Proximity to Easy Variants

David Wajc

Wednesday, 12.09.2012, 14:00

Taub 201

The field of Parameterized Complexity strives to solve intractable
problems efficiently, via multivariate analysis of running time, as a function of both the input size n and a parameter k. Such analysis enables to show that some of these problems are \emph{fixed parameter tractable} (FPT); in other words, they can be solved in time f(k)* n^O(1). The rationale behind this approach is the observation that many real-life inputs have small parameter values.
In this work we stud...

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Mathematical Analysis of Emergent Behavior in Multi-Agent Systems

Yotam Elor

Monday, 10.09.2012, 14:30

Taub 401

Emergence can be defined as the way complex systems and patterns arise out of a multiplicity of relatively simple interactions. Emergent behavior based systems are believed to be scalable and robust due to their non-reliance on a critical central element or fragile hierarchy. In the talk, two novel distributed algorithms based on emergent behavior will be presented and their scalability and robustness will be discussed....

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Haifux Club: The Resource-as-a-Service (RaaS) Cloud

Orna Agmon Ben-Yehuda (CS, Technion)

Monday, 03.09.2012, 18:30

Taub 6

Over the next few years, a new model of buying and selling cloud computing resources will evolve. Instead of providers exclusively selling server-equivalent virtual machines for relatively long periods of time (as done in today's IaaS clouds), they will increasingly sell individual resources (such as CPU, memory, and I/O resources) for a few seconds at a time. We term this nascent economic model of cloud computing the Resource-as-a-Service (RaaS) cloud, and we argue that its rise ...

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Combined Search Over Heterogeneous Repositories

Mirit Shalem

Sunday, 02.09.2012, 13:30

Taub 701

In complex search tasks that utilize information from several data sources, it is often required to pose several basic search queries, join the answers to these queries, where each answer is given as a ranked list of items, and return a ranked list of combinations.
Example: A tourist Alice wants to find a festive event that is related to classical music, a good Italian restaurant and an underground station that contains an elevator, such that all three will be located within a ...

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Haifux Club: Placing the Dots: On the Technical Challenges and Cultural Aspects of Typesetting Hebrew Vowel-Marks

Zvi Gilboa (University of Virginia)

Monday, 20.08.2012, 18:30

Taub 6

This lecture will discuss the challenges presented by Hebrew vowel marks (nikud) with respect to glyph-placement and kerning in (La)TeX and under Linux, as well as the various approaches to date to meet these challenges, and likewise the cultural aspects of their causes and implications....

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Haifux Club: Where did Bilski Take Us? Patentability of Software Related Inventions

Doron Sieradzki (pczlaw.com)

Monday, 06.08.2012, 18:30

Taub 6

In the last two decades patenting software relations invention in the US was a flourishing business. Recent ruling by Federal Court and its affirmation in the Supreme Court of the US may seriously affect this. We will review the current legal status of software related patents in the US in view of this ruling as well as relate to the legal status in Europe and Israel. The recently enacted America Invents Act (AIA) will also be reviewed....

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CGGC Seminar: Linear Asymptotic Subdivision Schemes for Curves and Positive Definite Matrices

Uri Itai (Applied Mathematics, Technion)

Sunday, 05.08.2012, 13:00

Room 337-8 Taub Bld.

Subdivision schemes are attractive methods for generating a smooth object from discrete data by repeating refinements. These schemes have many desirable properties such as fast convergence and smoothness of the generated objects. Therefore, subdivision schemes have gained popularity in recent years as an important tool in approximation theory, computer graphics, geometric design and computer aided design.
I will start with a survey on basic subdivision schemes. Then, I will revie...

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Pixel Club: Multi-Camera People Tracking

Horesh Ben Shitrit (École Polytechnique Fédérale de Lausanne (EPFL), Switzerland)

Tuesday, 31.07.2012, 11:30

EE Meyer Building 1061

At the CVLAB, EPFL, We have developed a multi-people tracking system.
Our system is able to reliably track multiple people in a multi-camera setting.
The obtained trajectories can be used for understanding individuals and group behavior.
For example, we are currently involved in a project whose goal is to understand the behavior of basketball teams and players from multiple video cameras.
Our system is composed of three core components: detection, identification and ...

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Pixel Club: Nearest-Neighbor Searching Under Uncertainty, and Matching a Noisy Curves to a Maps

Alon Efrat (CS, University of Arizona)

Monday, 30.07.2012, 11:30

Room 337-8 Taub Bld.

Nearest-neighbor queries, which ask for returning the nearest neighbor of a
query point in a set of points, are important and widely studied in many fields
because of a wide range of applications. In many of these applications, such as
sensor databases, location based services, face recognition, and mobile data,
the location of data is imprecise. We therefore study nearest neighbor queries
in a probabilistic framework in which the location of each input point and/or
query po...

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Haifux Club: Git for Solo Projects Too

Eli Billauer

Monday, 23.07.2012, 18:30

Taub 3

Git is well-known as the tool for collaborating in free software projects,
and the Linux kernel in particular. What seems to be less known, is how
useful it is even in a single developer scenario.
This is a slideless, demostration-based talk, walking through the practical
work with git as a most valuable tool for keeping a solo project under
control, and helping in real-life situations.
Git-savvy participants are also welcomed to share their experience.
...

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Pixel Club: Blind Source Separation of Underdetermined Time/Position Varying Mixtures

Yotam Michael (EE, Technion)

Tuesday, 17.07.2012, 11:30

EE Meyer Building 1061

Blind Source Separation (BSS) is a very applicable and well-studied problem. Most studies of the BSS problem
assume the system to be time/position invariant, an assumption which assists the mathematical study,
but is not guaranteed for real world situations. We present a method applicable to the case of
underdetermined time/position varying mixing systems, where number of mixture observation is limited to
be less than the number of sources and the system is changing with t...

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Secure Multiparty Computation with Minimal Interaction

Anat Paskin

Tuesday, 10.07.2012, 15:00

Taub 701

In the problem of secure multiparty computation (MPC) we have n parties who want to jointly evaluate a function f on their local inputs. An MPC protocol should allow the parties to correctly compute f while hiding the inputs from each other to the extent possible. An important complexity measure of MPC protocols is their round complexity. This talk will cover two questions related to the goal of minimizing the round complexity of MPC:
* Are there general MPC protocols which onl...

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Pixel Club: Regularization Cascade for Join

Alon Zweig (CS and Engineering, The Hebrew University of Jerusalem)

Tuesday, 10.07.2012, 11:30

EE Meyer Building 1061

We present a novel algorithm based on a cascade of regularization terms
designed to induce implicit hierarchical sharing of information among related learning
tasks. Our approach can be viewed as training and combining a set of diverse
classifiers. Such a combination is known to improve accuracy. The diversity is
achieved by inducing different levels of sharing among tasks. Our approach is
designed for multi-task and multi-class learning scenarios. Enabling different
levels ...

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Haifux Club: Hebrew search: not a trivial task (Hebmorph)

Itamar Syn-Hershko

Monday, 09.07.2012, 18:30

Taub 3

Search engines available today render almost useless when you need to process Hebrew texts. Even effective open-source solutions like Lucene/Solr give up in despair when handed a Hebrew corpus to index.
HebMorph is an open-source project with the ultimate goal of solving this problem, and in the best way possible. In-depth understanding of how search engines work triggers ideas, ideas become software parts, and those in turn are experimented with various state of the a...

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Bioinformatics Forum: Deciphering and Modeling the Gene Translation Code and Its Evolution via a Multidisciplinary Approach

Tamir Tuller (Laboratory of Computational Systems Biology, Biomedical Engineering, Tel Aviv University, Tel Aviv)

Wednesday, 04.07.2012, 15:30

Taub 701

Gene translation is a central process in all living organisms. Thus,
developing a better understanding of this complex process and its computational
modeling have ramifications to every biomedical discipline. We develop
computational models of gene translation and employ evolutionary systems
biology approaches to study how its efficiency is encoded in the transcripts.
The talk will include details about our models and several very recent
discoveries about the way evolution s...

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ceClub: Derandomizing Replication in Cloud

Asaf Cidon (Stanford University)

Wednesday, 04.07.2012, 11:30

EE Meyer Building 861

Randomized node selection is widely used in large-scale, distributed storage systems to both load balance chunks of data across the cluster and select replica nodes to provide data durability. We argue that while randomized node selection is great for load balancing, it fails to protect data under a common failure scenario. We present MinCopysets, a simple, general-purpose and scalable replication technique to improve data durability while retaining the benefits of randomized load...

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Pixel Club: Global Motion Estimation from Point Matches

Mica Arie-Nachimson (Math, Weizmann Institute of Science)

Tuesday, 03.07.2012, 11:30

EE Meyer Building 1061

Multiview structure recovery from a collection of images requires the
recovery of the positions and orientations of the cameras relative to a
global coordinate system. We present an approach to this problem that given
feature correspondences across pairs of images uses the pairwise Essential
Matrices to recover camera orientation by applying robust optimization
using either spectral or semidefinite programming relaxations. Once the
orientations are recovered we return to the...

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Pixel Club: Recent Results in 3D Urban Modelling

Andrei Sharf (Ben-Gurion University)

Thursday, 28.06.2012, 11:30

EE Meyer Building 1061

Today's scanning technologies, allow fast 3D scanning of urban scenes.
Such rapid acquisition incurs imperfections: large regions remain
missing, significant variation in sampling density is common, and the
data is often corrupted with noise and outliers.
Buildings often exhibit large scale repetitions and self-similarities.
To consolidate the imperfect data, our key observation is that the
same geometry, when scanned multiple times over reoccurrences of
instances...

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Activity Recognition Under Uncertainty using Petri Nets

Gal Lavee

Wednesday, 27.06.2012, 16:00

Taub 601

This talk considers the problem of recognizing activities in surveillance video. Activities are high-level non-atomic semantic concepts which may have complex temporal structure. Activities are not easily identifiable using image features, but rather by the recognition of their composing events. Unfortunately, these composing events may only be observed up to a particular certainty.
Many approaches to classification/recognition in computer vision rely on the availability of a larg...

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Spatial Proximity of Co-Regulated Yeast Genes

Shai Ben-Elazar

Wednesday, 27.06.2012, 14:30

Taub 401

While it has been long recognized that genes are not randomly disposed along the genome, the degree to which the three dimensional (3D)
structure of the genome influences the arrangement of genes has remained elusive. In particular, 'transcriptional-factories' are
thought to lead to the positioning co-regulated genes in physical proximity, however there have also been reports to the contrary.
Here we present evidence that the co-localization of yeast genes regulated by the same...

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ceClub: CORFU: A Shared-Log Design for Network-Attached Flash

Dahlia Malkhi (Microsoft Research, Silicon Valley)

Wednesday, 27.06.2012, 11:30

Room 337-8 Taub Bld.

CORFU* is a novel storage cluster design that pools a farm of
flash units and exposes it to clients as a single, global
shared-log. CORFU utilizes flash to break the seeming tradeoff
between consistency and performance, providing both strong
consistency guarantees and high throughput. Our implementation
is carried mostly by a client-side library, thus relieving the
service from any IO bottlenecks; a CORFU cluster of ...

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Approximation Algorithms for Resource Scheduling and Allocation Problems

Michael Beder

Wednesday, 27.06.2012, 11:30

Taub 601

We study the bandwidth allocation problem (BAP) and the storage allocation
problem (SAP) in bounded degree trees. In BAP, we are given a tree and a set of
tasks. Each task consists of a path in the tree, a bandwidth demand, and a
weight. Our goal is to find a maximum weight subset S of tasks such that, for
every edge e, the total bandwidth of demand in S whose path contains e does not
exceed the edge's capacity. In SAP it is also required that every task in the
solution is g...

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Pixel Club: PLAYING 20 QUESTIONS WITH CORRUPTED ANSWERS: Applications to Object Localization and Tracking

Raphael Sznitman (Ecole Politechnique Federale de Lausanne, Switzerland)

Tuesday, 26.06.2012, 14:30

EE Meyer Building 1061

The problem of search is ubiquitous in computer vision, and perhaps most common in object detection and localization. While the last few decades have produced a wealth of methods to evaluate the presence of a target at a given location, the search problem remains particularly difficult. This is in large part due to detection methods being far from perfect and that solutions with ever more challenging constraints are demanded. For example, more complex objects need to be found in i...

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Recursion in Distributed Computing

Sergio Rajsbaum

Tuesday, 26.06.2012, 14:30

Room 337-8 Taub Bld.

...

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Haifux Club: ZeroVM: Lightweight Containers Based on Google Native Client

Camuel Gilyadov (LiteStack)

Monday, 25.06.2012, 18:30

Taub 3

How cloud-friendly is traditional virtualization? As a matter of fact, all traditional virtualization technologies predate cloud era. Traditional virtualization has major advantage, they are backward compatible on binary level, making it easy to run in cloud any existing pre-cloud application. But what if backward compatability is not a requirement? What about new post-cloud applications, that are developed specifically for cloud? Is traditional virtualization still a good platfor...

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Theory Seminar: From Irreducible Representations to Locally Decodable Codes

Klim Efremenko (Tel-Aviv University)

Wednesday, 20.06.2012, 12:30

Taub 201

Locally Decodable Code (LDC) is a code that encodes a message in a way that one can decode any particular symbol of the message by reading only a constant number of locations, even if a constant fraction of the encoded message is adversarially corrupted.
In this talk we will show connection between LDC and a representation theory.
We show that if there exists an irreducible representation (\rho, V) of a group G and q elements g_1,g_2,..., g_q
in $G$ such that the...

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ceClub: Sharing Virtual Memory between CPU and GPU

Boris Ginzburg (Intel Institute of Computational Intelligence)

Wednesday, 20.06.2012, 11:30

Room 337-8 Taub Bld.

This talk will discuss some system issues related to sharing virtual memory between CPU and GPU, which brings new challenges: GPU page faults, flashing a TLB on GPU, etc. We will also describe ESFIR - an SVM prototype, and XTHREAS - a new SVM programming models, which extends pthread semantics to GPU. ...

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TrustPack: a Decentralized Trust Management Framework

Amit Portnoy

Tuesday, 19.06.2012, 15:00

Taub 701

With the rise of the internet and its applications, it has became more and more
common for unfamiliar parties to interact with each other. In order to help and
encourage such interactions trust management systems were introduced. Those systems
try to alleviate mistrust by gathering and processing statistical information
about previous events.
This thesis describes TrustPack, a trust management framework that provides
trust management as a service, i.e., TrustPack is separated fro...

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Principles of Reasoning with Graphical Models

Rina Dechter

Tuesday, 19.06.2012, 14:30

Room 337-8 Taub Bld.

...

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Pixel Club: Place-Based Information Systems: Textual Location Identification and Visualization

Hanan Samet (CS, University of Maryland)

Tuesday, 19.06.2012, 11:30

Faculty meeting room, 7th floor, Rabin bldg

The popularity of web-based mapping services such as Google Earth/Maps and Microsoft Virtual Earth (Bing), has led to an increasing awareness
of the importance of location data and its incorporation into both web-based search applications and the databases that support them.
In the past, attention to location data had been primarily limited to geographic information systems (GIS), where locations correspond to spatial objects and are usually specified geometrically.
However,...

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A Semantic Approach To Graphic User Interface Programming

Motty Porat

Wednesday, 13.06.2012, 14:30

Taub 601

It is sometimes required to run the same application program on different
platforms, from smartphones to PC's. The application may have to employ
different User Interfaces (UI's) on different platforms, e.g. a UI designed for
a large PC screen may not fit into the small screen of a smartphone. A different
version of the application may therefore be needed for each platform kind.
Kantorowitz and Lyakas introduced the use of platform-independent semantic user
interfaces. As a res...

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Continuous Symmetries of Non-rigid Shapes

Carmi Grushko

Wednesday, 13.06.2012, 14:30

Taub 401

Our world is known for its abundance of symmetric structures - in the fields of
the animal kingdom, in astronomy, mathematics and chemistry, to name a few.
The existence of symmetry in 3D shapes is of great interest when such applications as
efficient storage, comparison and lookup are considered.
Traditionally, only symmetries which are a composition of rotations and reflections
were considered. These symmetries, termed extrinsic, have limited use in non-rigid
shapes, as they a...

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Theory Seminar: Tight Bounds for Parallel Randomized Load Balancing

Christoph Lenzen (The Hebrew University of Jerusalem)

Wednesday, 13.06.2012, 13:00

Taub 201

TBA...

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Active Learning Theory and Practice

Ron Begleiter

Wednesday, 13.06.2012, 12:30

Taub 601

Supervised learning, one of the core models of machine learning, is concerned with inducing rules from a given sample of examples. Active learning is a variant of this model in which the learning algorithm can choose which examples to learn from. The performance of such active learners is measured by the "speed" of learning: The number of examples they consume in order to produce a competitive solution.
In this talk, I will present a novel active learning algorithmic concept, and...

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ceClub: Improved Bounds for Byzantine Self-Stabilizing Clock Synchronization

Christoph Lenzen (Weizmann Institue of Science)

Wednesday, 13.06.2012, 11:30

EE Meyer Building 1061

The challenging task of Byzantine self-stabilizing pulse synchronization requires that, in the presence of a minority of nodes that are permanently maliciously faulty, the non-faulty nodes must start firing synchronized pulses in a regular fashion after a finite amount of time, regardless of the initial state of the system. We study this problem under full connectivity in a model where nodes have local clocks of unknown, but bounded drift, and messages are delayed for an unknown, ...

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Autonomous Navigation within an Indoor Environment

Boris Cherevatsky

Wednesday, 13.06.2012, 10:30

Taub 601

We address the problem of robot navigation using natural visual features in a
planar environment. The algorithm gets as an input a target, which is represented
by a captured image from the targets pose, and a source image, captured from the
starting position and should make an accurate move towards the target which can
be decomposed as a rotation and translation on the plane.
This algorithm can be used as a step in a higher level homing algorithm for
visual navigation. In additio...

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Pixel Club: Multiscale Framework for Discrete Energy Minimization

Meirav Galun (CS, Applied Mathematics, Weizmann Institute of Science)

Tuesday, 12.06.2012, 11:30

EE Meyer Building 1061

Discrete energy minimization is a ubiquitous task in computer vision, yet it is NP-hard in most cases. In this work we propose a multiscale framework for coping with the NP-hardness of discrete optimization. Our approach utilizes algebraic multiscale principles to efficiently explore the discrete solution space, yielding improved results on challenging energies for which current methods provide unsatisfactory approximations. In contrast to popular multiscale methods in computer vi...

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Theory Seminar: On Identity Testing of Tensors, Low-rank Recovery and Compressed Sensing

Michael Forbes (MIT)

Wednesday, 06.06.2012, 12:30

Taub 201

Let M be a low-rank matrix. For vectors x,y, define the bilinear form f(x,y)=x^t M y. We study the question of reconstructing M from evaluations to f. Much of previous work allowed randomized evaluations, or a stronger query model (or both). We show how to, in an optimal number of 4nr measurements, efficiently reconstruct M from deterministically chosen queries to f. This can be seen as a (noiseless) generalization of compressed sensing, and we make this connection formal by r...

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The surprises of Quick Sort

Micha Hofri

Tuesday, 05.06.2012, 14:30

Room 337-8 Taub Bld.

...

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Pixel Club: Bounded Distortion Mapping Spaces for Triangular Meshes

Yaron Lipman (Weizmann Institute of Science)

Tuesday, 05.06.2012, 11:30

EE Meyer Building 1061

In this talk we introduce generic convex spaces of bounded distortion piecewise linear mappings of triangular meshes. It is shown how common geometric processing objective functionals can be restricted to these new spaces, rather than to the entire space of piecewise linear mappings, to provide a bounded distortion version of popular algorithms....

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TCE Guest Lecture: Lane Decoupling for Improving the Timing-Error Resiliency of Wide-SIMD Architectures

Mattan Erez (University of Texas at Austin)

Sunday, 03.06.2012, 15:30

EE Meyer Building 1061

A significant portion of the energy dissipated in modern integrated circuits is consumed by the overhead associated with timing guardbands that ensure reliable execution. Timing speculation, where the pipeline operates at an unsafe voltage with any rare errors detected and resolved by the architecture, has been demonstrated to significantly improve the energy-efficiency of scalar processor designs. Unfortunately, applying the same timing-speculative approach to wide-SIMD architect...

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CGGC Seminar: On the possibility of simple parallel computing of Voronoi diagrams and Delaunay Graphs

Daniel Reem (IMPA, Rio, Brasil)

Sunday, 03.06.2012, 13:00

Room 337-8 Taub Bld.

Although many algorithms for computing Euclidean Voronoi diagrams of point sites have been published, most of them are sequential in nature and hence cast inherent difficulties on the possibility to compute the diagrams in parallel. We present a new algorithm which enables the (combinatorial) computation of each of the Voronoi cells independently of the other ones. The algorithm is significantly different from previous ones and some of the ideas related to it are in the spirit of ...

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CSL Lucnheon: Verifying Atomicity of Composed Concurrent Operations

Ohad Shacham

Thursday, 31.05.2012, 12:30

Room 337-8 Taub Bld.

In the last two decades, program verification and testing have gone a long way from a concept to practical tools which can be applied to real software. In this work, we developed practical techniques for testing and verifying atomicity of composed concurrent operations. The techniques have been implemented in a tool (COLT) and successfully applied to uncover many bugs in real software. In fact, the Java library is currently being modified to avoid some of the bugs found by COLT. T...

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Safe Zones: An Efficient Approach to Distributed Monitoring

Amir Abboud

Wednesday, 30.05.2012, 16:30

Taub 601

Many monitoring tasks over distributed data streams can be formulated
as a continuous query using a function that is defined over the
global average of data vectors derived from the streams.
The query will typically produce an alert when the value of
the function crosses a predefined threshold.
A fundamental problem in efficient scalable implementation of
such threshold queries is that the data streams are
distributed, sometimes over a wide geographical region.
Moving a...

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Coverage-Driven Refinement of Conceptual Representations

Haggai Toledano

Wednesday, 30.05.2012, 13:30

Taub 601

Many text processing tasks are based on estimating semantic relatedness between texts. For example, in information retrieval, relevancy of documents can be determined based on the semantic distance from the query. Recently, many algorithms have been developed for evaluating semantic relatedness based on a conceptual representation of the input texts. The concept spaces for these algorithms are based, in most cases, on large repositories of knowledge, such as Wikipedia and Wordnet....

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Theory Seminar: From Irreducible Representations to Locally Decodable Codes

Ofer Neiman (Ben-Gurion University)

Wednesday, 30.05.2012, 12:30

Taub 201

Given a set of $n$ points in $\ell_{1}$, how many dimensions are needed to represent all pairwise distances within a specific distortion ? This dimension-distortion tradeoff question is well understood for the $ell_{2}$ norm, where $O((\logn)/\epsilon^{2})$ dimensions suffice to achieve $1+\epsilon$ distortion. In sharp contrast, there is a significant gap between upper and lower bounds for dimension reduction in $\ell_{1}$. A recent result
shows that distortion $1+\epsilon$ can ...

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Pixel Club: Incremental Light Bundle Adjustment For SfM And Multi-robot Localization

Vadim Indelman (Robotics and Intelligent Machines (RIM) Center, College of Computing, Georgia Institute of Technology)

Wednesday, 30.05.2012, 11:30

EE Meyer Building 1061

Fast and reliable bundle adjustment is essential in many structure from motion (SfM) related applications such as mobile vision, augmented reality and robotics. In this talk an incremental and computationally efficient method for bundle adjustment will be presented. The method incorporates two key ideas to substantially reduce the involved computational cost, compared to a conventional bundle adjustment. First, the cost function is formulated in terms of multi-view constraints ins...

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ceClub: A Virtual Mobile Smartphone Architecture

Oren Laadan (CS, Columbia University)

Wednesday, 30.05.2012, 11:30

EE Meyer Building 861

Smartphones are increasingly ubiquitous, and many users carry multiple phones to accommodate work, personal, and geographic mobility needs. We present Cells, a virtualization architecture for enabling multiple virtual smartphones to run simultaneously on the same physical cellphone in an isolated, secure manner. Cells introduces a usage model of having one foreground virtual phone and multiple background virtual phones. This model enables a new device namespace mechanism and novel...

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Computing in the 21st Century: The Georgia Tech Model

Zvi Galil

Tuesday, 29.05.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Reporting Neighbors in High-Dimensional Euclidean Space

Dror Aiger (Google)

Tuesday, 29.05.2012, 11:30

EE Meyer Building 1061

We consider the following problem, which arises in many database and
web-based applications: Given a set $P$ of $n$ points in a high-dimensional space
$\reals^d$ and a distance $r$, we want to report all pairs of points of $P$
at Euclidean distance at most $r$. We present two randomized algorithms, one
based on randomly shifted grids, and the other on randomly shifted and rotated
grids.
The expected performance of both algorithms is of the form $C(d)(n+k)\log n$, ...

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ceClub: Dr. Philip M. Merlin Memorial Lecture and Prize Award: Scheduling Algorithms for the 4G Cellular Networks

Reuven Cohen (CS, Technion)

Wednesday, 23.05.2012, 14:30

EE Meyer Building 1003

Cellular networks are becoming more and more crucial to our daily lives and operators are seeking new technologies for increasing their bandwidth. Examples for such technologies are cell sectorization, fractional frequency reuse, and coordinated multipoint Tx/Rx. To take advantage of these new technologies, the scheduler logic at the base station needs to determine not only when to transmit each packet but also what modulation and coding scheme to use, which frequency reuse area's...

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Theory Seminar: Optimal Testing of Multivariate Polynomials over Small Prime Field

Elad Haramaty ( (CS, Technion)

Wednesday, 23.05.2012, 12:30

Taub 201

We consider the problem of testing if a given function f is close to a n-variate degree d polynomial over the finite field of q elements. The natural, low-query, test for this property would be to pick the smallest dimension t= t(q,d )≈ d/q such that every function of degree greater than d reveals this feature on some t-dimensional affine subspace and to test that f when restricted to a random t-dimensional affine subspace is a polynomial of degree at most d on this subspace. S...

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The Complexity of Cryptography

Yuval Ishai

Tuesday, 22.05.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Human Attributes from 3D Pose Tracking

Micha Livne (CS, University of Toronto)

Tuesday, 22.05.2012, 11:30

EE Meyer Building 1061

This talk concerns the estimation of human attributes from 3D
human pose and motion. We consider both physical attributes (eg, gender and
weight) and aspects of mental state (eg, mood). This task is useful for
man-machine communication, and it provides a natural benchmark for
evaluating the performance of 3D pose tracking methods. Based on an
extensive corpus of motion capture data, with physical and perceptual
ground truth, we analyze the inference of subtle biologically-in...

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Theory Seminar: Extractors for Polynomials Sources over Constant-Size Fields of Small Characteristic

Ariel Gabizon (CS. Technion)

Wednesday, 16.05.2012, 12:30

Taub 201

Let F be the field of q elements, where q=p^l for prime p. Informally
speaking, a polynomial source is a distribution over F^n
sampled by low degree multivariate polynomials. In this paper, we
construct extractors for polynomial sources over fields of constant
size q assuming p...

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ceClub:Dynamic Reconfiguration of Primary/Backup Clusters

Alex Shraer (Yahoo! Research)

Wednesday, 16.05.2012, 11:30

Room 337-8 Taub Bld.

Dynamically changing (reconfiguring) the membership of a replicated distributed system while preserving data consistency and system availability is a challenging problem. In this talk I will discuss this problem in the context of Primary/Backup clusters and Apache Zookeeper. Zookeeper is an open source system which enables highly reliable distributed coordination. It is widely used in industry, for example in Yahoo!, Facebook,Twitter, VMWare, Box, Cloudera, Mapr, UBS, Goldman Sach...

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Haifux Club: InfiniBand, RoCE and RDMA Verbs - Empowering Supercomputing and Data Center Interconnects

Dotan Barak (Mellanox)

Monday, 14.05.2012, 18:30

Taub 3

This lecture aims to provide a brief introduction to the InfiniBand™
architecture and programming using RDMA verbs. InfiniBand is an open
standard, used in HPC (supercomputing) and data center environments
for high performance connectivity.
This standard defines a complete fabric architecture, from the
physical layer all the way to the programming API. The programming
API, also known as RDMA verbs, allows for transparent memory
operations over the network, tra...

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Theory Seminar: Fully Dynamic Approximate Distance Oracles for Planar Graphs via Forbidden-Set Distance Labels

Shiri Chechik (Weizmann Institute of Science)

Wednesday, 09.05.2012, 12:30

Taub 201

Distance oracle is a data structure that provides fast answers to distance queries.
Recently, the problem of designing distance oracles capable of answering restricted distance queries, that is, estimating distances on a subgraph avoiding some forbidden vertices, has attracted a lot of attention. In this talk, we will consider forbidden set distance oracles for planar graphs. I’ll present an efficient compact distance oracle that is capable of handing any number of failures.
...

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ceClub: Self-Adjusting Networks and Distributed Data Structures

Chen Avin (Ben Gurion University)

Wednesday, 09.05.2012, 11:30

EE Meyer Building 861

We study self-optimizing networks and data structures. The goal of this research line is the design of fully distributed algorithms which flexibly adapt the network to a dynamic environment such as changing demands or traffic patterns. The idea of self-adjusting networks is motivated by trends in today's Internet like large data centers and peer-to-peer networks.
In this talk I will preset the general model of the problem and some initial theoretical results on data ce...

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Functions which are close to being k-local are juntas

Guy Kindler

Tuesday, 08.05.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Viewpoint-Aware Object Detection and Pose Estimation

Daniel Glazner (Faculty of Mathematics and Computer Science
The Weizmann Institute of Science)

Tuesday, 08.05.2012, 11:30

EE Meyer Building 1061

We describe an approach to category-level detection and viewpoint estimation
for rigid 3D objects from single 2D images. In contrast to many existing
methods, we directly integrate 3D reasoning with an appearance-based voting
architecture. Our method relies on a nonparametric representation of a
joint distribution of shape and appearance of the object class. Our voting
method employs a novel parametrization of joint detection and viewpoint hypothesis
space, allowing efficien...

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Haifux Club: Scientific Python

Uri Barkan

Monday, 07.05.2012, 18:30

Taub 3

See Hebrew announcement....

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Theory Seminar: Random Arithmetic Formulas can be Reconstructed Efficiently

Ankit Gupta (CS, Technion)

Wednesday, 02.05.2012, 12:30

Taub 201

What is an optimal formula computing a given multivariate polynomial $f$? In this work, we show that this question admits an efficient algorithmic solution in an average-case sense.
Specifically, we consider the following situation. Let $\F$ be a field, $S \subseteq \F$ be a finite subset of field elements, $\vecX =(X_1, X_2, \ldots, X_n) $ be a tuple of formal variables and $\Delta \geq 0 $ be an integer representing the product-depth of the hidden (unknown) formula. ...

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How Do Classes Choose Their Parents? (Preferential Attachment to the Trial)

Yossi Gil

Tuesday, 01.05.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Learning Feature Descriptors

Alex Bronstein (School of Electrical Engineering, Tel Aviv University)

Tuesday, 01.05.2012, 11:30

EE Meyer Building 1061

SIFT-like local feature descriptors are ubiquitously employed in such computer vision applications as content-based retrieval, video analysis, copy detection, object recognition, photo-tourism, and 3D reconstruction from multiple views. Feature descriptors can be designed to be invariant to certain classes of photometric and geometric transformations, in
particular, affine and intensity scale transformations. However, real transformations that an image can undergo can only be app...

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Extracting Meaning from Search Behavior Data

Eugene Agichtein

Tuesday, 24.04.2012, 14:30

Room 337-8 Taub Bld.

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Haifux Club: Modern Web Development in Perl

Gabor Szabo

Monday, 23.04.2012, 18:30

Taub 3

Back in the early years of the dynamic web, Perl was the de-facto
choice of language.
It was so ubique that people associated it with CGI. For that, even today, Perl
suffers from a bad image. Even though, under the visible surface,
there are strong powers leading to a much better future.
In the last couple of years a new bread of frameworks appeared in the
Perl world.
They are all based on the PSGI standard that rhymes to WSGI and...

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Theory Seminar: Pseudorandom Generators with Large Stretch and Low Locality from Random Local One-Way Functions

Benny Applebaum, Tel-Aviv University

Sunday, 22.04.2012, 13:00

Taub 201

Locally-computable pseudorandom generators (PRGs) map n random input bits into m>n pseudorandom bits such that each of the m outputs depend on a small number of d inputs. While it is known that such generators are likely to exist for the case of small sub-linear stretch m=n+n^{0.9}, it is less clear whether achieving larger stretch is possible. The existence of such PRGs, which was posed as an open question in previous works, has recently gained an additional motivation due to sev...

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CGGC Seminar: Towards Unencumbered 3D Teleconferencing Systems

Tiberiu Popa (Computer Graphics Laboratory , ETH, Zurich)

Thursday, 19.04.2012, 11:15

Room 337-8 Taub Bld.

With the recent development of auto-multiscopic 3D displays that provide a 3D experience without the use of glasses, and with the recent
availability of inexpensive hybrid depth/color cameras such as the Kinect, that provide real-time geometric and texture information,
we are a step closer to realizing unencumbered 3D teleconferencing systems. However, many challenges still remain to be solved.
In this talk, I will present two teleconferencing software solutions bas...

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TCE Lecture: Green Cellular Networks: A Survey, Some Research Issues and Challenges

Vijay K. Bhargava (University of British Columbia and President, IEEE Communications Society)

Wednesday, 18.04.2012, 11:30

Room 337-8 Taub Bld.

In this talk, we present techniques to enable green communications in future generation of wireless systems that will rely on cooperation and cognition to meet increasing demand of high data rate. So far, achieving high data rate has been the primary focus of research in cooperative and CR systems, without much consideration of energy efficiency. However, many of these techniques significantly increase system complexity and energy consumption. Escalating energy costs and environme...

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Improved Competitive Ratio for the Matroid Secretary Problem

Oded Lachish

Tuesday, 17.04.2012, 14:30

Room 337-8 Taub Bld.

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Adaptive Reconstruction Methods for Low-Dose Computed Tomography

Yossi Shtok

Thursday, 05.04.2012, 11:30

Taub 337

The main problem with contemporary Computed Tomography (CT) imaging is the high radiation
dose absorbed by patients during the screening. Reducing this dose may result in poor quality
imaging when using the popular fast and direct reconstruction techniques. On the other hand,
iterative methods powered by statistical models of the scan are better-performing in such cases,
but are also very slow. To bridge the gap between these two solutions, various signal processing
techniques tha...

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Resource Management in Grid Environments

Pavel Bar

Wednesday, 04.04.2012, 14:00

Taub 601

Grid computing environments have become mission-critical components in
research and industry, offering sophisticated solutions to exploit large
computing and storage resources across multiple geographic locations and
administrative domains. Usually, such grid resources are non-dedicated or
opportunistic, as a consequence users will utilize the resources following
a "best effort" approach. However, many real-world supercomputing
applications, such as computational fluid dynam...

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Algebraic Collocation Coarse Approximation (ACCA) in Multigrid

Ran Zemach

Wednesday, 04.04.2012, 12:30

Taub 601

Most algebraic multigrid (AMG) methods define the coarse operators by applying the (Petrov-) Galerkin coarse approximation (GCA) where the sparsity pattern and operator complexity of the multigrid hierarchy are dictated by the multigrid transfer operators (prolongation and restriction).
Therefore, AMG algorithms must usually settle on some compromise between the quality of the transfer operators and the aggressiveness of the coarsening, which affect the complexity of the hierarchy...

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Labelings and Partitions of Graphs

Roy Schwartz

Wednesday, 04.04.2012, 12:30

Taub 201

The study of combinatorial problems with a submodular objective function has
attracted much attention in recent years, and is partly motivated by the importance
of such problems to combinatorial optimization, economics, and algorithmic game theory.
A partial list of well-known problems captured by submodular maximization includes:
Max-Cut, Max-DiCut, Max-k-Cover, Generalized-Assignment, several variants of Max-SAT
and some welfare and scheduling problems.
While classical wor...

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Theory Seminar: Labelings and Partitions of Graphs

Roy Schwartz (CS, Technion)

Wednesday, 04.04.2012, 12:30

Taub 201

The study of combinatorial problems with a submodular objective function has
attracted much attention in recent years, and is partly motivated by the importance
of such problems to combinatorial optimization, economics, and algorithmic game theory.
A partial list of well-known problems captured by submodular maximization includes:
Max-Cut, Max-DiCut, Max-k-Cover, Generalized-Assignment, several variants of Max-SAT
and some welfare and scheduling problems.
While cla...

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[ Full version ]

Determining the Winner of a Dodgson Election is Hard

Professor Frances Rosamond

Tuesday, 03.04.2012, 14:30

Room 337-8 Taub Bld.

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Bioinformatics Forum: Biomed Data at Work

Eugene Kolker (Children's Hospital, University of Washington)

Tuesday, 03.04.2012, 13:30

Shelter seminar room, Biology, Technion

Access to high-quality data drives our ability to ask questions and
find answers. Our lab has a number of projects based on this premise.
Proteomics data from experimental research in diabetes has enabled the discovery
of two promising beta cell regulators, Netrin and Sem3a. We have built MOPED, a
human and model organisms’ protein expression database, to provide a
comprehensive summary of publicly available proteomics data. With MOPED, users
can browse, sort, query, visua...

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Pixel Club: Generalized Projection Based M-estimator

Peter Meer (Electrical and Computer Engineering Department
Rutgers University)

Tuesday, 03.04.2012, 11:30

Room 337-8 Taub Bld.

A new robust estimation algorithm, the generalized projection based
M-estimator (gpbM) is proposed. The algorithm is general and can handle
heteroscedastic data where every point in the estimation have a different
covariance. Does not require the user to specify any (scale) parameters,
and can be applied to multiple linear constraints for single and
multi-carrier problems. The gpbM has three distinct stages: scale estimation,
robust model estimation and inlier/outlier dich...

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Haifux Club: Automatic Parallelization in GCC

Razya Ladelsky (IBM R&D, Haifa)

Monday, 02.04.2012, 18:30

Taub 3

With the emergence of multicore architectures there is a growing need for automatic parallelization, that distributes sequential code into multi threaded code. OpenMP defines language extensions to C, C++, and Fortran for implementing multi-threaded shared memory applications. Generation of such extensions by the compiler relieves programmers from the manual parallelization process. OpenMP specification has been implemented in GCC, and is part of the standard release since version...

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CSL Luncheon: Automatic fine-grain locking using shape properties

Guy Gueta

Thursday, 29.03.2012, 12:30

Room 337-8 Taub Bld.

We present a technique for automatically adding fine-grain locking to an abstract data type that is implemented using a dynamic forest -i.e., the data structures may be mutated, even to the point of violating forestness temporarily during the execution of a method of the ADT. Our automatic technique is based on Domination Locking, a novel locking protocol. Domination locking is designed specifically for software concurrency control, and in particular is designed for object-oriente...

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The algorithmization of causes and counterfactuals

Judea Pearl, Special Guest Talk, Harvey Prize and Turing Award Winner,

Thursday, 29.03.2012, 11:00

CS Taub Build. Auditorium 2

...

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Cache or Charge? Cooperative Caching with Credits

Gala Yadgar

Wednesday, 28.03.2012, 12:30

Taub 601

In cooperative storage caching, clients may access blocks directly from each other's
caches. Previous studies treated all the cooperating caches as a single pool,
maximizing overall system performance at the price of possibly degraded performance
for individual clients. In light of the popularity of many P2P mechanisms, we
re-evaluate the concept of cooperative caching, considering selfish clients that
cooperate only if they benefit from the interaction. This is the first st...

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Theory Seminar: On the complexity of the Furthest Hyperplane Problem

Zohar Karnin (Yahoo! Research)

Wednesday, 28.03.2012, 12:30

Taub 201

This paper introduces the Furthest Hyperplane Problem (FHP), which is an unsupervised counterpart of Support Vector Machines. Given a set of n points in R^d, the objective is to produce the hyperplane (passing through the origin) which maximizes the separation margin, that is, the minimal distance between the hyperplane and any input point. To the best of our knowledge, this is the first paper achieving provable results regarding FHP. We provide both lower and upper bounds to this...

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ceClub: Improving Virtualization Performance Through Phy

Nadav Amit (CS, Tehcnion)

Wednesday, 28.03.2012, 11:30

Taub 401

Machine virtualization, where many virtual machines run on a single physical machine, has become an increasingly popular area of research and development in the last decade. Despite the introduction of hardware support for machine virtualization in commodity servers, many workloads still suffer from degraded performance when run in virtual machines. This degradation can be particularly acute when an unmodified virtual machine -- a VM that is not aware it is running in a virtual en...

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Parameterizing on the Number of Numbers

Prof. Michael Fellows

Tuesday, 27.03.2012, 14:30

Room 337-8 Taub Bld.

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TCE Lecture: Consistent Hashing, Danny Lewin, and the Creation of Akamai

Tom Leighton (Applied Math, MIT)

Tuesday, 27.03.2012, 11:00

Butler Auditorium, Mosad Neeman Building,Technion

In 1996, twelve years after making Aliyah to Israel, Danny Lewin graduated from the Technion and came to MIT to study algorithms. Over the next few years, he wrote a prize-winning Master’s Thesis on Consistent Hashing and co-founded Akamai Technologies, which today accelerates the delivery of over 250,000 web sites, including all of the top media and commerce brands on the Web.
In this talk, we will describe some of Danny’s early work on consistent hashing and how ...

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e-club: How to Start a Start-Up

Ofer Vilenski (Jungo)

Monday, 26.03.2012, 18:30

Taub 337

Have you always dreamed to start a Start-up and didn't know how? Come to meet, hear and ask those who made it big time!...

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CSpecial Talk: Unified Algorithms for Online Learning and Competitive Analysis

Shahar Chen (CS, Tehcnion)

Sunday, 25.03.2012, 16:30

Taub 601

Online learning and competitive analysis are two widely studied frameworks for online decision-making settings. Despite the frequent similarity of the problems
they study, there are significant differences in their assumptions, goals and techniques, hindering a unified analysis and richer interplay between the two. In this
work, we provide several contributions in this direction. We provide a single unified algorithm which by parameter tuning, interpolates between optimal regr...

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Approximating Semidefinite Programs In Sublinear Time

Dan Garber

Wednesday, 21.03.2012, 16:00

Taub 701

Semidefinite programming is a fundamental problem in convex programming with numerous applications. In the field of combinatorial optimization, many approximation algorithms that rely on sdp have been discovered in the past two decades starting with the work of Goemans and Williamson on MAX-CUT. In the field of machine learning solving sdps is at the heart of many learning tasks such as learning a distance metric and matrix completion. In ML in particular, the amounts of data nowa...

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Automatic Extraction of Subcategorization Frames for Hebrew

Hanna Fadida

Wednesday, 21.03.2012, 14:30

Taub 701

Verb subcategorization frames determine the number and types of the syntactic arguments that verbs
select, or subcategorize for. Typically, verbs can be associated with subcategorization frames that
specify, for each subcategorized argument, information on the phrases that can realize this
argument. These can be noun phrases (in the case of direct objects), prepositional phrases with one
or more specific preposition, infinitival verb phrases, clauses introduced by a complemen...

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Bioinformatics Forum: Global sampling of Macromolecular Association Energy landscapes using Fast Fourier Transforms and their Generalizations

Dima Kozakov (Biomedical Engineering, Boston University)

Wednesday, 21.03.2012, 13:00

Seminar room, 4th floor, Emerson building, Technion

Sampling energy landscape of macromolecular interactions is a challenging
problem of computational biology. Classical approaches like Molecular
Dynamics and Monte Carlo are not always optimal for these applications due
to large configurational space of the problem. On contrary The Fast Fourier
Transform (FFT) correlation sampling approach can exhaustively evaluate the
energies of billions of macromolecular configuratins on a grid provided two
limitations - the energy is des...

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Theory Seminar: Monotone Unification Problems

Pavel Hrubes (Princeton University)

Wednesday, 21.03.2012, 12:30

Taub 201

Given two monotone polynomials f,g, their unifier is a pair of monotone polynomials u,v such that f=cu+v and g=u+cv, for some c>0.
The problem I will discuss is: can we have monotone polynomials f,g which have a unifier, they can be computed by a small monotone circuit, but every unifier of f,g requires a large monotone circuit?
On one hand, the question is related to arithmetic circuit complexity, and on the other, to the complexity of proofs in subsystems of monoto...

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Pixel Club: Not Your Typical Pixel: On "Cortical Vision" without Visual Cortex

Ohad Ben-Shahar (Ben-Gurion University)

Tuesday, 20.03.2012, 11:30

EE Meyer Building 1061

Our visual attention is attracted by salient stimuli in our environment and affected by primitive features such as orientation, color, and motion. Perceptual saliency due to orientation contrast has been extensively demonstrated in behavioral experiments with humans and other primates and is commonly explained by the very particular functional organization of the primary visual cortex. We challenge this prevailing view by studying orientation-based visual saliency in two non-mamma...

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Haifux Club: Software Tools for Reconfigurable Architectures

Victor Kaplansky (IBM R&D, Haifa)

Monday, 19.03.2012, 18:30

Taub 6

Reconfigurable computing allows a lower power consumption to achieve higher performance than software, while maintaining a higher level of flexibility than hardware. Reconfigurable devices, such as field-programmable gate arrays (FPGAs), contain an array of computational elements whose functionality is determined through multiple programmable configuration bits. The hardware can be re-programmed to implement an entirely different circuit.
The focus of the research proj...

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ceClub: PCI Express: Technology, Road Map and Design Challenges

Rick Eads (Agilent Technologies)

Monday, 19.03.2012, 15:30

EE Meyer Building 861

PCI Express is an industry standard, and the most prominent interconnection architecture for I/O devices and other boards inside a computer. It is defined and updated by the PCI-SIG(R) industry standards body, originally formed in 1992 as the Peripheral Component Interconnect (PCI) special interest group (SIG). Agilent Technologies, a prominent developer and provider of test equipment at all levels yet not a competitor in the computer market, has played a key role in the advanceme...

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Pixel Club: Geometric constraints in shape analysis

Dan Raviv (CS, Tehcnion)

Monday, 19.03.2012, 10:30

Room 337-8 Taub Bld.

Traditional models of bendable surfaces are based on the exact or approximate invariance to deformations that do not tear or stretch the shape, leaving intact an intrinsic geometry associated with it.
Intrinsic geometries are typically defined by shortest paths also known as geodesic distances, or diffusion processes on the surface like diffusion distances.
Both methods are implicitly derived from the metric induced by the ambient Euclidean space.
Here, we depart from...

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CSL Luncheon: From Sequential to concurrent: Correctness and Relative

Srivastan Ravi (TU Berlin/Deutsche Telekom Laboratories)

Thursday, 15.03.2012, 12:30

Room 337-8 Taub Bld.

It seems to be generally accepted that designing correct and efficient concurrent software is a sophisticated task that can only be held by experts. A crucial challenge then is to convert sequential code produced by a ``mainstream' programmer into concurrent one. Various synchronization techniques may be used for this, e.g., locks or transactional memory, but what does it mean for the resulting concurrent implementation to be correct? And which synchronization primitives provide m...

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Quantum Neural Computation and Associative Memory

Tamer Salman

Wednesday, 14.03.2012, 16:30

Taub 701

This thesis presents quantum analogues of artificial neural networks.
We analyze and compare their performance to known classical and previously proposed quantum models.
First we propose a model for associative memory based on a modification of Grover's quantum search algorithm
and prove that the capacity of the model is exponential in the number of bits.
We present algorithms for pattern completion and correction and prove that the model does not suffer from spurious me...

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A Study of Data Structures with a Deep Heap Shape

Haggai Eran

Wednesday, 14.03.2012, 15:00

Taub 701

Computing environments become increasingly parallel, and it seems likely that we
will see more cores on tomorrow's desktops and server platforms. In a highly
parallel system, tracing garbage collectors may not scale well due to deep heap
structures that hinder parallel tracing. In this work we start by analyzing
which data structures make current Java benchmarks create deep heap shapes. It
turns out that the problem is manifested mostly with benchmarks that employ
queues and linke...

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Finding Malware on a Web Scale

Ben Livshits SPECIAL GUEST LECTURE,

Wednesday, 14.03.2012, 14:30

Room 539 Taub Bld.

...

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Violation Resolution in Distributed Stream Networks

David Ben-David

Wednesday, 14.03.2012, 13:00

Taub 701

Threshold monitoring applications in distributed stream networks contin-
uously monitor the global score of the network and alert whenever a given
threshold is crossed. The network's global score is computed by applying
a certain scoring function over the aggregated data derived from the
network streams. However, the sheer volume and dynamic nature of the
streams impose excessive communication overhead.
Recently, the concept of local constraints have been presented in which
...

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Theory Seminar: Causality, Knowledge and Coordination in Synchronous Systems

Ido Ben-Zvi (EE, Technion)

Wednesday, 14.03.2012, 12:30

Taub 201

Coordinating the proper ordering of events across remote sites is a central task
of distributed applications. In asynchronous systems, such coordination depends in an essential way upon message chains, as captured by Lamport's
happened-before relation. The relation provides a useful approximation of
causality, in the sense that in asynchronous systems two event can only be
causally related if they are Lamport related.
The talk will consider coordination and causali...

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Bioinformatics Forum: Systems Biology of Viral Pathogenesis and Immunity: Where are Google and IBM?

Michael G. Katze (University of Washington, Seattle)

Wednesday, 14.03.2012, 11:30

Taub 401

After decades of research, vaccines against some of the greatest
viral threats are still lacking and antiviral drugs remain few and slow in
coming. These shortcomings point to the need for new approaches that go
beyond traditional virology methods. High-throughput technologies and
computational biology promise to deliver a much-needed boost to the field.
My laboratory is using systems biology and computational approaches to
understand and model integrated views of virus-ho...

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TCE Guest Lecture: Obstacles and Chances for Multi-core Deployment in Hard Real-time Systems

Theo Ungerer (CS, University of Augsberg, Germany)

Tuesday, 13.03.2012, 14:30

EE Meyer Building 861

Providing higher performance than state-of-the-art embedded processors can deliver today will increase safety, comfort, number and quality of services, while also lowering emissions as well as fuel demands for automotive, avionic and automation applications. Engineers who design hard real-time embedded systems in such embedded domains express a need for several times the performance available today while keeping safety as major criterion. A breakthrough in performance is expected ...

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NUMA and locality aware multi-core software

Elad Gidron

Monday, 12.03.2012, 14:00

Taub 701

Emerging computer architectures pose many new challenges for software development. First, as the number
of computing elements constantly increases, the importance of scalability of parallel programs becomes
more significant. Second, accessing memory has become the principal bottleneck, while multi-CPU systems
are based on NUMA architectures, where memory access from different chips is asymmetric. Therefore,
it is important to design software with local data access, cache-friendl...

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Learning Linear Support Vector Machines in Sublinear Time

Tomer Koren

Wednesday, 07.03.2012, 14:30

Taub 701

In recent years, stochastic approximation approaches such as Stochastic
Gradient Descent (SGD) and Stochastic Dual Averaging have become the
optimization method of choice for many learning problems, including linear
Support Vector Machines (SVMs). This is not surprising, since such methods
yield optimal generalization guarantees with only a single pass over the data.
They in a sense have an unbeatable runtime: the runtime to get to a desired
generalization goal is the same as the ...

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Approximation Algorithm for Soft-Capacitated Connected Facility

Assaf Rappaport

Tuesday, 06.03.2012, 14:00

Taub 601

Data centers are becoming the hosting platform for a wide spectrum of
composite applications. In recent years, large investments have been
made in massive data centers supporting cloud services, by companies
such as eBay, Facebook, Google, Microsoft, and Yahoo!. With an
increasing trend towards global and more communication intensive
applications, the bandwidth usage within and between data centers is
rapidly growing. The placement of the data used by these global
applications pre...

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Matrix Learning: A Tale of Two Norms

Nati Srebro

Wednesday, 29.02.2012, 14:30

Room 337-8 Taub Bld.

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Polar codes: construction and improved decoding

Ido Tal

Tuesday, 28.02.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Hierarchical Invariant Sparse Modeling for Image Analysis

Leah Bar (Mathematics, Tel Aviv University)

Tuesday, 21.02.2012, 11:30

EE Meyer Building 1061

Sparse representation theory has been increasingly used in signal processing
and machine learning. In this work we introduce a hierarchical sparse modeling approach which integrates information from the image patch level to derive a mid-level invariant image and pattern representation. The proposed framework is based on a hierarchical architecture of dictionary learning for sparse coding in a cortical (log-polar) space, combined with a novel pooling operator which incorporates th...

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Haifux Club: Making Hebrew Slides with LaTeX and Beamer

Gai Shaked

Monday, 20.02.2012, 18:30

Taub 6

LaTeX is a high-quality typesetting system; BEAMER is is a LaTeX class for creating presentations; Hebrew is an esoteric west Semitic language we happen to speak. This talk will cover all three, by the end of the talk you will be able to create beautiful and comprehensive Hebrew presentations using Beamer in minutes.
The talk assumes prior knowledge in Hebrew, but not in LaTeX nor Beamer. We will cover basic concepts, commands and examples in depth, and finally add som...

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On the Complexity of the Regenerator Location Problem - Treewidth and Other Parameters

Itamar Hartstein

Sunday, 19.02.2012, 11:30

Taub 701

We deal with the Regenerator Location Problem in optical networks. We are given a network G = (V, E), and a set Q of communication requests between pairs of terminals in V. We investigate two variations: one in which we are given a routing P of the requests in Q, and one in which we are required to find also the routing. In both cases, each path in P must contain a regenerator after every d edges in order to deal with loss of signal quality for some d > 0. The goal is to minimize ...

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Synthesizing Concurrent Relational Data Structures

Roman Manevich

Tuesday, 14.02.2012, 14:30

Room 337-8 Taub Bld.

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Geometric Methods for Analyzing and Monitoring Large Distributed Data

Guy Sagy

Wednesday, 08.02.2012, 13:00

Taub 601

A basic requirement in many distributed systems is the ability to
detect objects whose score, according to a given function, exceeds
some threshold. Since an object's data can be partitioned over various
nodes, computing its global score requires collecting its data over
the network. A main challenge is to perform threshold queries or
monitoring with minimum network communication, i.e., without
collecting the data from the nodes to a central location.
In this talk I will present ...

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ceClub: Synthesizing Concurrent Relational Data Structures

Roman Manevich (UT Austin)

Wednesday, 08.02.2012, 11:30

EE Meyer Building 861

Efficient concurrent data structures are extremely important for obtaining good performance for most parallel programs. However, ensuring the correctness of concurrent data structure implementations can be very tricky because of concurrency bugs such as race conditions and deadlocks. In systems that use optimistic parallel execution such as boosted transactional memory systems and the Galois system, the implementation of concurrent data structures is even more complex because data...

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Multiparty Computation from Somewhat Homomorphic Encryption

Ivan Damgaard

Tuesday, 07.02.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Tissue Microenvironment Magnetic Resonance Imaging (TM-MRI) of the body: A Reliable Quantitative Biomarker for Personalized Treatment Paradigms

Moti Freiman (Computational Radiology Lab, Harvard Medical School)

Tuesday, 07.02.2012, 11:30

EE Meyer Building 1061

Personalized treatment approaches which optimize drugs doses according to pre-treatment and early response-to-therapy evaluation hold the promise to improve treatment success rates and reduce severe adverse side-effects due to drugs toxicity in variety of pathologies. Reliable assessment of tissue microenvironment including cell proliferation, density and size and tissue perfusion as a biomarker for disease activity is a key necessity for personalized, response-based treatment reg...

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Haifux Club: C++ AMP: Microsoft approach for Heterogeneous Computing

Avi Mendelson (Microsoft and CS&EE, Technion)

Monday, 06.02.2012, 18:30

Taub 6

C++ AMP (Accelerated Massive Parallelism) is a native programming model that contains elements that span the C++ programming language and its runtime library. The syntactic changes introduced by AMP are minimal, but additional restrictions are enforced to reflect the limitations of data parallel hardware. Data parallel algorithms are supported by the introduction of multi-dimensional array types, array operations on those types, indexing, asynchronous memory transfer, shared memor...

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Random Sampling Preconditioners

Haim Avron SPECIAL GUEST TALK-

Monday, 06.02.2012, 14:30

Room 337-8 Taub Bld.

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Utilizing Multiple Radio Interfaces in Wireless Networks

Alex Kogan

Wednesday, 01.02.2012, 11:00

Taub 601

Contemporary mobile devices are equipped with multiple wireless interfaces, such as WiFi, Bluetooth,
WiMax, ZigBee, NFC, etc. All these technologies differ dramatically one from another in maximum
transmission range, bandwidth and power demands. Among all subsystems operating inside mobile devices,
wireless communication is known as being particularly power-hungry, accounting for 50-70% of the total
power consumption in small handheld devices, such as smartphones, and for ...

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The Plural Architecture: Shared Memory Many-cores with Hardware Scheduling

Ran Ginosar

Tuesday, 31.01.2012, 15:30

Room 337-8 Taub Bld.

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How Your Smartphone Can Use Game-Theory to Valet-park Your Car

Ouri Wolfson

Tuesday, 31.01.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Diverse M-best Solutions in MRFs

Greg Shakhnarovich (TTI-Chicago)

Tuesday, 31.01.2012, 11:30

Room 337-8 Taub Bld.

Much effort has been directed at algorithms for obtaining the highest
probability (MAP) configuration in a probabilistic (random field) model. In
many situations, one could benefit from additional solutions
with high probability. Current methods for computing additional most probable
configurations produce solutions that tend to be very similar to the MAP
solution and each other. This is often an undesirable property. I will describe
an algorithm for the M-Best Mode problem,...

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CSL Luncheon: Cache or Charge? Cooperative Caching with Credits

Gala Yadgar (CS, Technion)

Thursday, 26.01.2012, 12:30

Room 337-8 Taub Bld.

In cooperative storage caching, clients may access blocks directly from each other’s caches. Previous studies treated all the cooperating caches as a single pool, maximizing overall system performance at the price of possibly degraded performance for individual clients. In light of the
popularity of many P2P mechanisms, we re-evaluate the concept of cooperative caching, considering selfish clients that cooperate only if they benefit from the interaction. This is the first study ...

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Exploiting Morphology in Identifying Multiword Expressions from Multilingual Parallel Corpora

Daniel Hurwitz

Wednesday, 25.01.2012, 12:30

Taub 601

Our research discusses multi-word expressions (MWE) such as "kick the bucket", "hot dog", "by and large", "look up, and "spill the beans". Identification of MWEs has been a hot subject of research in recent years. We present a method to identify MWEs in Hebrew using a new concept we term Language Isolation. We focus on dissecting (or "isolating") the morphological properties of words to discover potential MWEs and show that this method improves the alignment of multi-lingual (Span...

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Theory Seminar: Coin Flipping with Constant Bias Implies One-Way Functions

Eran Omri (Bar-Ilan University)

Wednesday, 25.01.2012, 12:30

Taub 201

It is well known (c.f., Impagliazzo and Luby [FOCS '89]) that the
existence of almost all ``interesting" cryptographic applications,
i,e., ones that cannot hold information theoretically, implies one-way
functions. An important exception where the above implication is not
known, however, is the case of coin-flipping protocols. Such protocols
allow honest parties to mutually flip an unbiased coin, while
guaranteeing that even a cheating (efficient) party cannot bias the
outp...

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Pixel Club: Visual Audio Denoising

Dana Segev (EE, Technion)

Tuesday, 24.01.2012, 11:30

EE Meyer Building 1061

Audio denoising is a long studied problem, with numerous algorithms and a
wide accumulated knowledge. Considering non-stationary noise (like noise in
a cocktail party environment) and strong, this task becomes very difficult
to handle. This paper considers such audio denoising problems, where the
audio track is accompanied by a video. Furthermore, the disturbing source
is generally not visible in the field of view, and its nature is unknown.
Overcoming such unknown noise is ...

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David Carmel

Sunday, 22.01.2012, 12:30

Taub 3

David Carmel, from IBM Research, Haifa, wil talk about the IBM Watson project. The talk is given in the course 'Introduction to Artificial Intelligence", but is open to the public....

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Theory Seminar: A Polylogarithmic-Competitive Algorithm for the $k$-Server Problem

Niv Buchbinder (Open University )

Wednesday, 18.01.2012, 12:30

Taub 201

The $k$-server problem is one of the most fundamental and extensively studied problems in online computation. Suppose there is an $n$-point metric space and $k$ servers are located at some of the points of the metric space. At each time step, an online algorithm is given a request at one of the points of the metric space, and this request is served by moving a server to the requested point (if there is no server there already). The cost of serving a request is defined to be the di...

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ceClub: Distributed Average Consensus and Coherence in Dynamic Networks

Stacy Patterson (EE, Technion)

Wednesday, 18.01.2012, 11:30

EE Meyer Building 861

In the distributed average consensus problem, each node in a network has an initial value, and the objective is for all nodes to reach consensus at the average of these values using only communication with nearby nodes. Distributed average consensus algorithms have a wide variety of applications, including distributed optimization, sensor fusion, load balancing, and autonomous vehicle formation control.
This talk centers on the analysis of distributed averaging algorit...

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Vector Diffusion Maps and the Connection Laplacian

Amit Singer

Tuesday, 17.01.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: The Role of Target Fixations in the Process of Recognition

Michal Jacob (Intel, Computer Vision Group)

Tuesday, 17.01.2012, 11:30

Room 337-8 Taub Bld.

Why do we perceive some elements in a visual scene, while others remain
undetected? We compared fixations on detected vs. undetected items in the
Identity Search Task (Jacob & Hochstein, 2009). Using a gaze-contingent
technique, we further controlled the number of fixations on the target
(Jacob & Hochstein, 2010). Results show that detected targets were fixated
at a greater extent, and a backward dynamics alignment revealed a
bifurcation point where the differential characte...

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CSL Luncheon: A Social Storage System for Mobile Ad-Hoc Networks

David Sainz (CS, Technion)

Thursday, 12.01.2012, 12:30

Room 337-8 Taub Bld.

Smart-phones are quickly becoming the most prevalent computing and
communication devices. As the capabilities of these mobile phones improve as
well as our reliance on them, backing up the data stored on the phone becomes
vital. Typical cloud based backup services assume reliable high bandwidth
connection to the Internet. This assumption, however, in not practical in many
places, which motivates the need for ad-hoc cloud services, and in particular,
for a social storage service th...

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Definability of Combinatorial Functions

Tommer Kotek

Wednesday, 11.01.2012, 14:30

Taub 601

The complexity of several prominent graph polynomials, such as the chromatic polynomial
and the matching polynomial, has been studied in the literature. In 2008 Makowsky raised
a conjecture which generalizes complexity results for specific graph polynomials
to an infinite class of graph polynomials which include almost all of those in the
literature. The conjecture states roughly that the evaluations of such graph polynomials
are equivalent in terms of running-time complexity, ...

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Making Computers Good Listeners

Joseph Keshet

Wednesday, 11.01.2012, 14:30

Room 337-8 Taub Bld.

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Theory Seminar: Detecting Dangerous Queries: A New Approach for Chosen Ciphertext Security

Brent Waters (University of Texas)

Wednesday, 11.01.2012, 12:30

Taub 201

I will present a new approach for creating chosen ciphertext secure encryption.
The focal point of our work is a new abstraction that we call Detectable Chosen
Ciphertext Security (DCCA). Intuitively, this notion is meant to capture systems
that are not necessarily chosen ciphertext attack (CCA) secure, but where we can detect
whether a certain query CT can be useful for decrypting (or distinguishing) a challenge
ciphertext CT*.
We show how to build chosen ...

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ceClub: Persistent OSPF Attacks

Gabi Nakibly (National EW Research and Simulation Center)

Wednesday, 11.01.2012, 11:30

Taub 337

Open Shortest Path First (OSPF) is the most popular interior gateway routing protocol on the Internet. Most known OSPF attacks that have been published in the past are based on falsifying the link state advertisement (LSA) of an attacker-controlled router. These attacks can only falsify a small portion of the routing domain's topology, hence their effect is usually limited. More powerful attacks are the ones that affect LSAs of other routers not controlled by the attacker. However...

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Missing Heritability: New algorithmic and statistical approaches

Or Zuk

Tuesday, 10.01.2012, 14:30

Room 337-8 Taub Bld.

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Pixel Club: Pose Estimation and Recognition using Specular Highlights

Margarita Osadchy (CS, Haifa University)

Tuesday, 10.01.2012, 11:30

EE Meyer Building 1061

We presents a novel approach to pose estimation and model-based recognition of
specular objects in difficult viewing conditions, such as low illumination,
cluttered background, and large highlights and shadows that appear on the
object of interest. In such challenging conditions conventional features are
unreliable. We show that under the assumption of a dominant light source,
specular highlights produced by a known object can be used to establish
correspondence between its ...

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Haifux Club: Maqaf Hataf Patakh - The new standard Hebrew Keyboard Layout

Amir E. Aharoni

Monday, 09.01.2012, 18:30

Taub 6

In the last two years a committee in the Standards Institution of Israel worked, on my initiative and with my active participation, on a revision for the standard of the Hebrew keyboard layout. Why did i want to change the layout? Why is it good to do it through the Standards Institution? How to make people who represent Microsoft, Linux, and Apple agree about things? How is a keyboard layout edited in Linux and in Windows? How do you install a keyboard layout and how do you distr...

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Efficient and Exact Inter-Sentence Decoding for Natural Language Processing

Roi Reichart

Monday, 09.01.2012, 14:30

Room 337-8 Taub Bld.

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Fast Distributed Computing Despite Poor Connectivity

Keren Censor-Hillel

Sunday, 08.01.2012, 14:30

Room 337-8 Taub Bld.

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Theory Seminar: Subspace Evasive Sets

Zeev Dvir (Princeton University)

Thursday, 05.01.2012, 12:30

Taub 601

We describe an explicit, simple, construction of large subsets of F^n,
where F is a finite field, that have small intersection with every
k-dimensional affine subspace. Interest in the explicit construction
of such sets, termed 'subspace-evasive' sets, started in the work of
Pudlak and Rodl (2004) who showed how such constructions over the
binary field can be used to construct explicit Ramsey graphs. More
recently, Guruswami (2011) showed that, over large finite fields (of
...

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Algorithmic cooling of spins using optimal control

Yossi Attiya

Wednesday, 04.01.2012, 13:30

Taub 601

Nuclear magnetic resonance (NMR) has proven to be a leading implementation of quantum information processors where each molecule in the sample constitutes a register of quantum bits (qubits). However, at room temperature, the qubits that are realized by nuclear spins (1/2) are in a highly mixed state: noisy or with high entropy. Source coding (compression) can cool some spins (reducing their Shannon entropy) while heating others, yet this closed-system technique is limited by Shan...

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Theory Seminar: Homomorphic Encryption: from Private-Key to Public-Key

Ron Rothblum (Weizmann Institute for Science)

Wednesday, 04.01.2012, 12:30

Taub 337

We show how to transform any additively homomorphic private-key
encryption scheme that is compact, into a public-key encryption
scheme. By compact we mean that the length of a homomorphically
generated encryption is independent of the number of ciphertexts
from which it was created. We do not require anything else on the
distribution of homomorphically generated encryptions (in
particular, we do not require them to be distributed like real
ciphertexts).
Our resul...

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ceClub: Graph Matching and Clustering on the GPU

Rob Bisseling (Utrecht University)

Wednesday, 04.01.2012, 11:30

Taub 9

Graph matching is the problem of matching nodes of a graph in pairs such that the largest number of pairs is created or the largest sum of edge weights is obtained. Greedy graph matching provides us with a fast way to coarsen a given graph during graph partitioning. Direct algorithms on the CPU which perform such greedy matchings are simple and fast, but offer few handholds for parallelisation. To remedy this, we introduce a fine-grained shared-memory parallel algorithm for greedy...

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The complexity of counting constraint satisfaction problem

Andrei Bulatov

Tuesday, 03.01.2012, 14:30

Room 337-8 Taub Bld.

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ceClub: Load Balancing for SIP Server Clusters

Erich Nahum (IBM T.J. Watson Research Center)

Tuesday, 03.01.2012, 12:45

Taub 337

The Session Initiation Protocol (SIP) is widely used for controlling communication sessions such as voice and video calls over IP, video conferencing, streaming multimedia distribution, instant messaging, presence information, file transfer and online games. This work introduces several novel load balancing algorithms for distributing SIP requests to a cluster of SIP servers. Our load balancer improves both throughput and response time versus a single node, while exposing a single...

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Pixel Club: Contour-Based Joint Clustering of Multiple Segmentations

Daniel Glasner (Math & CS, The Weizmann Institute of Science)

Tuesday, 03.01.2012, 11:30

EE Meyer Building 1061

We present an unsupervised, shape-based method for joint clustering of multiple
image segmentations. Given two or more closely-related images, such as close
frames in a video sequence or images of the same scene taken under different
lighting conditions, our method generates a joint segmentation of the images.
We introduce a novel contour-based representation that allows us to cast the
shape-based joint clustering problem as a quadratic semi-assignment problem.
Our score fun...

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Haifux Club: GPGPU - Case studies, Do's and Dont's (Part 4 out of 4 talks series)

Ofer Rosenberg and Yaki Tebeka (AMD)

Monday, 02.01.2012, 18:30

Taub 337

This is a 4 series of 4 talks about GPGPUS, intended for the practical engineer:
1. Motivation, AMD's architecture
2. OpenCL
3.Case studies, Dos and Don'ts
4.Tools and Profiling for Performance
General Purpose GPU programming became a hot topic in the last few years, ranging from academic studies to being used by commercial software products. As an example, three out of the world's top10 supercomputers (June2011 list) contain GPUs in them. This s...

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Semantic Model Differencing for Software Evolution

Shahar Maoz

Sunday, 01.01.2012, 14:30

Room 337-8 Taub Bld.

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