ידיעון 2019/20 | אוניברסיטת תל אביב

EE Seminar: On massively multithreaded DSP architecture

08 במרץ 2017, 15:30

חדר 011, בניין כיתות-חשמל

Speaker: Ben Perach

M.Sc. student under the supervision of Prof. Shlomo Weiss

Wednesday, March 8^th 2017 at 15:30

Room 011, Kitot Bldg., Faculty of Engineering

On massively multithreaded DSP architecture

Abstract

Processor designers attempt to gain performance by introducing new, more efficient architectures. Digital signal processors (DSP) are designed to process very efficiently digital signal applications. This focus allows DSP designers to select tradeoffs that may not be appropriate for general purpose processors. For example, typical power consumption of DSPs is measured in milliwatts while the power used by an Intel state-of-the-art processor is in the range of tens of watts. In recent years we have seen a growing use of GPUs by non-graphical scientific applications because of their computation capabilities.

In this work we introduce a new DSP architecture, designed on the basis of the same parallel processing principles used in GPU architectures.

We implement this new architecture on FPGA, show evaluation results for widely used DSP algorithms and evaluate die area and power consumption.

We achieve similar computation speeds as in GPUs, with reduced die area and power consumption due to the use of hardware adaptations for DSP applications.

EE Seminar: Resource Allocation For LDPC-coded multi-carrier Downlink Channels

08 במרץ 2017, 15:00

חדר 011, בניין כיתות-חשמל

Speaker: Max Bluvshtein,

M.Sc. student under the supervision of Dr. Ofer Amrani

Wednesday, March 8^th, 2017 at 15:00

Room 011, Kitot Bldg., Faculty of Engineering

Resource Allocation For LDPC-coded multi-carrier Downlink Channels

Abstract

Various techniques have been proposed to address the problem of resource allocation for multi-carrier communications, i.e. Orthogonal frequency-division multiplexing (OFDM) systems. They can be categorized by the type of criteria they aim at optimizing. These criteria, for the most part, arise either from information-theoretic measures such as channel capacity, or from measures that describe the error performance of a channel, which does not necessarily model the coding being employed.

In this work, we propose an optimization technique that is tailored for low density parity-check (LDPC) coded OFDM systems, by employing the so-called general stability condition introduced by Richardson et. al. ("Design of capacity-approaching irregular low-density parity-check codes"). The latter formulates a necessary condition for the Belief-Propagation (BP) decoder to perfectly decode a received vector with no errors.

We re-formulate the general condition so as to model practical multi-carrier/multi-user systems such as OFDMA and OFDRMA (OFDM with random multiple-access). By doing so, a general framework for resource allocation is laid down and employed herein to optimize the transmitted power based on the characteristics of LDPC-coded systems. Fortunately, a convex optimization problem is obtained, whose closed-form solution is elaborated upon in this work. The proposed optimization technique is utilized for performing power allocation in OFDMA and OFDMRA systems in a way that minimizes the transmitted power while guaranteeing reliable decoding.

To validate this technique, it is compared to information-theoretic methods that aim at optimizing the mutual-information between the transmitter and receiver. It is shown that both provide almost identical performance for all the scenarios addressed in this work.

EE Seminar: Coresets for Kinematic Data: From Theorems to Autonomous Toy-Drones

(The talk will be given in English)

Speaker: Dr. Dan Feldman
Robotics & Big Data Lab, Computer Science Department, University of Haifa

Monday, March 13^th, 2017
15:00 - 16:00

Room 011, Kitot Bldg., Faculty of Engineering

Coresets for Kinematic Data: From Theorems to Autonomous Toy-Drones

Abstract

A coreset (or core-set) of a dataset is its semantic compression with respect to a set of queries, such that querying the (small) coreset provably yields an approximate answer to querying the original (full) dataset. However, we are not aware of real-time systems that compute coresets in a rate of dozens of frames per second.

I will suggest a framework to turn theorems to such systems using coresets. This is by maintaining such a coreset for kinematic (moving) set of n points, and run algorithms on the small coresets, instead of the n points, in realtime using weak devices.

This also enabled my group to implement a low-cost (< $100) mini-computer with a wireless system that tracks a toy (and harmless) quadcopter which guides guests to a desired room (in a hospital, mall, hotel, museum, etc.) with no help of additional human or remote controller. I will present the system as well as extensive experimental results.

A joint work with Soliman Nasser and Ibrahim Jubran

13 במרץ 2017, 15:00

חדר 011, בניין כיתות-חשמל

EE Seminar: Computational aspects of communication

(The talk will be given in English)

Speaker: Dr. Elad Haramaty
School of Engineering and Applied Sciences, Harvard University

Monday, March 20^th, 2017
15:00 - 16:00

Room 011, Kitot Bldg., Faculty of Engineering

Computational aspects of communication

Abstract

Communication has played a growing role in our lives over the past decade. It often becomes a bottleneck in the performance of our daily tasks. This motivates the pursuit for more efficient communication. However, efficiency is becoming more challenging from the computational aspect, due to several of its characteristics in modern communications.

One such characteristic is the interactivity of the protocols in today's noisy communication environments. One natural approach to overcome such a challenge is called Interactive Coding. Interactive coding is an efficient black-box mechanism to convert any interactive protocol that performs well under noiseless environment into one that is also resilient to errors, while preserving the efficiency of the protocol.

Another characteristic which challenges today’s communications is the dynamic and interactive nature of modern protocols. This may lead to desynchronization between the communicating parties. However, until now, almost all designed systems assume that both parties are perfectly synchronized and all context is shared perfectly by the communicating agents. Thus, any violation of those protocols leads to a breakdown in communication.

This talk will address both of the aforementioned challenges.The first part of the talk will be devoted to interactive coding and in the second part, we will focus on designing protocols under uncertainty of the shared context.

Bio

Elad Haramaty is a postdoctoral researcher at Harvard University in the School of Engineering and Applied Sciences with Madhu sudan.
Previously, he was a postdoc in Northeastern University with Emanuelle Viola. He earned his PhD from the Technion under the guidance of Amir Shpilka, and completed undergraduate work at the Technion in the mathematics department. His research interests cover a broad range of theoretical computer science, especially algebraic complexity and communication related questions.

20 במרץ 2017, 15:00

חדר 011, בניין כיתות-חשמל

EE Seminar: Secure Group Testing

(The talk will be given in English)

Speaker: Dr. Asaf Cohen
Department of Communication Systems Engineering,Ben Gurion University

Monday, May 15^th, 2017
15:00 - 16:00

Room 011, Kitot Bldg., Faculty of Engineering

Secure Group Testing

Abstract

The principal mission of Group Testing (GT) is to identify a small subset of defective items from a large population, by grouping items into as little as possible test pools. The test outcome of a pool is positive if it contains at least one defective item, and is negative otherwise. GT algorithms are utilized in numerous applications, and in most of them the privacy of the tested subjects, namely, whether they are defective or not, is critical. In this talk, we consider a scenario where there is an eavesdropper (Eve) which is able to observe a subset of the GT outcomes (pools). We propose a new non-adaptive Secure Group Testing (SGT) algorithm based on information theoretic principles, which keeps the eavesdropper ignorant regarding the items’ status. Specifically, when the fraction of tests observed by Eve is 0 ≤ δ < 1, via random coding, ML decoding and a matching converse, we prove that the number of tests required for both correct reconstruction at the legitimate user (with high probability) and negligible mutual information at Eve’s side is 1/(1−δ) times the number of tests required with no secrecy constraint. We conclude with a practical SGT decoding algorithm, and asses its performance as well.

Based on joint work with Alejandro Cohen, Omer Gurewitz and Sidharth Jaggi.

15 במאי 2017, 15:00

חדר 011, בניין כיתות-חשמל

School of Mechanical Engineering Prof. Sefi Givli

15 במאי 2017, 14:00

בניין וולפסון חדר 206

ללא תשלום

School of Mechanical Engineering Prof. Sefi Givli

School of Mechanical Engineering Seminar
Monday, May 15, 2017 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

Bi-stability and multi-stability in structures

Prof. Sefi Givli

Faculty of Mechanical Engineering, Technion -Israel Institute of Technology

A wide range of intriguing mechanical phenomena is related to bi-stability and multi-stability. Examples are the shape memory effect and super-elasticity observed in materials undergoing martensitic phase transformations, the mechanical behavior of nano-pillars under compression, and the saw-tooth pattern observed in single molecule experiments of structural proteins such as titin. All these structures are characterized by a wiggly energy landscape and multiple metastable configurations.

In the past few years, we have developed theoretical models aiming at providing insights into the mechanical behavior of such structures. In this talk I will present some of our findings, with emphasis on consequences of discreteness in structures undergoing discrete phase transformations, such as nano-pillars and unfolding/refolding of proteins, and also mechanical aspects of the continuum-level behavior of structures undergoing remodeling or spatial organization of their composition.

Bio: Dr. Sefi Givli Earned his B.Sc (1994) in the Faculty of Mechanical Engineering at Technion. He then served in the Israeli Air-Force as a field engineer and as a system engineer for the F-15/16 jet engines. He joined again the Faculty of Mechanical Engineering at Technion in 2000 for PhD studies (direct track). He then moved to Caltech for a two-year postdoc with Prof. Kaushik Bhattacharya at the department of Mechanical Engineering, where his research has expanded towards mechanics of micro-scale biological systems. Sefi returned to ME Technion in October 2008, where he serves as Assist. Prof. since then.

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Departmental Seminar - Materials Science and Engineering: Prof. Nava Setter

24 באפריל 2017, 15:00 - 16:00

בניין וולפסון, חדר 118

ללא תשלום

Departmental Seminar: Materials Sciences and Engineering

Prof. Nava Setter

Faculty of Engineering, Swiss Federal Institute of Technology - EPFL
Department of Materials Science and Engineering, Tel Aviv University

Venus of Moravia and Reconfigurable Nanoelectronics: 30,000 years of Ceramics Engineering

Room 118, Wolfson Mechanical Engineering Building

Abstract:

The oldest existing (wo)man-made materials are 28,000-years old ceramic objects, found near Brno (Czech Republic). Modern ceramics technology

follows similar production principles but the scale has changed: A sub 10

nm brick-by-brick design is feasible and in-situ reconfigurable micro- and
nanostructures are more than mere objects of the imagination.

The seminar will be focused on a particular group of ceramic materials called
ferroelectrics and the research towards their implementation in reconfigurable
nano-electronics. Ferroelectrics are part of so-called ‘smart materials’, materials
that change their properties under external stimuli. They are widely used in
electronics and communications, electromechanics, and acoustics. An important
feature, inherent to all ferroelectrics, even in a perfect single crystal form is the
existence of domain walls. These are internal interfaces, 1-3 nm wide, that can
be manipulated by voltage pulses or mechanical stress.

For the past 5 years, the internal structure and properties of domain walls
have been intensively studied. We have learned to position and displace them,
functionalize them, and make domain wall arrays having desired patterns.
Among the obtained results are domain walls with metallic conductivity
inside the electrically insulating ferroelectric, dense patterns of domain arrays
having <10 nm periodicity, monitored displacement of domain walls, and a
demonstrated reconfigurability, promising new possibilities for domain-wall
control and its utilization.

Full Invitation

סמינר מחלקתי ביה"ס להנדסה מכאנית Prof. Gil Yosilevskii

20 במרץ 2017, 14:00

School of Mechanical Engineering Seminar
Monday, March 20, 2017 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

HYDRODYNAMICS OF A SWIMMING EEL

Prof. Gil Yosilevskii

Technion Fac. Aero & Space

Eels swim by generating short lateral displacement waves that propagate backwards along the body of the fish faster than it swims. Hydrodynamic theory of elongated swimmers predicts that if the amplitude of the displacement waves does not increase toward the tail, the part of the fish behind of its widest point takes no part in propulsion. It also predicts that if the amplitude does increase toward the tail, then the hydrodynamic propulsion efficiency suffers.

Cusk eels reach their maximal width right behind their heads, and the bulk of their locomotive muscles (myomeres) is located aft of the widest section. Indeed, they swim so that the amplitude of the propulsion wave increases as it propagates along the fish. Does it imply that these fish evolved inefficient swimmers? As compared with cusk eels, true eels have much longer body aft of the widest section and have their locomotive muscles distributed along their entire length - but they swim as cusk eels, using only the tail. Does it imply that these fish deliberately choose an inefficient swimming gait? What is the optimal swimming gait of an eel? Answers to these questions will be given in the talk.

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