School of Mechanical Engineering Seminar
Monday, November 27, 2017 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

An afternoon talk on femurs, arteries and high order finite element methods

Prof. Zohar Yosibash

School of Mechanical Engineering, Tel Aviv University

Predicting the mechanical response of human femurs and arteries is of major clinical importanceare for diagnostic purposes as well as for patient-specific treatment. Such prediction capabilities are being described which involve the combination of high order finite element (FE) methods, medical imaging and experimental observations.

Our research on human femurs will first be addressed, where we use quantitative computerized tomography (qCT scans) that enables a computer realization of subject-specific bone models. Combining qCT scans with high order FE simulations and a large set of experiments provide the opportunity to accurately simulate patient-specific femur’s response, allowing orthopedic surgeons to plan a proper patient specific treatment. Examples of the use of our methods in clinical practice for treatment of metastatic bone tumors will be provided.

If time allows, experimental and numerical methods for the analysis of human arteries will be addressed. Arteries are complex anisotropic structures undergoing large deformations and strains and are subject to active response due to contraction of smooth muscle cells. Attempts to properly describe their response will be described.

About the Lecturer

Prof. Yosibash received his B.Sc. in Aeronautical Engineering from the Technion (87), his M.Sc. in Applied Mathematics from Tel-Aviv Unviersity (92) and D.Sc. in Mechanical Engineering from Washington University, St. Louis, USA (94). He joined Ben-Gurion University in 1995 and since 2008 he is a full professor of mechanical engineering. He has been a visiting professor at Brown Univ from 2002-2007, and at the Technical Univ of Munich during 2010-2011. He received the Toronto prize for excellence in research at BGU in 2009. Prof. Yosibash was a Hans Fischer Senior Fellow at the Institute for Advanced Study at the Technical University of Munich (2009-2012) and serves as the scientific ambassador since 2013.  Prof. Yosibash joined the School of Mechanical Engineering at TAU in Oct 2017. He is the head of the lab for computational mechanics and experimental biomechanics at TAU and since 2015 serves as the president of the Israel Association for Computational Methods in Mechanics.

You are invited to attend a lecture

Higher Order Modulation Backscatter Combined with WPT as a Solution for IoT Development

:By

Nuno Borges Carvalho

Professor Catedrático, Dep. Electronica, Telecomunicacoes e Informatica

Instituto de Telecomunicacoes, Universidade de Aveiro

Aveiro,  Portugal

Abstract

The Internet-of-Things (IoT) vision calls for thousands interconnected devices in wearables, vehicles, buildings, using a multitude of sensors to provide us with useful information.

Backscatter communication provides an enabling technology to address the needs of IoT, due to the simplicity of the tag circuit and the ability to minimize the usage of batteries or even completely eliminate them taking advantage of wireless power transmission as well as energy harvesting. This talk presents the latest advances in backscatter communication technology, covering a wide range of topics, focusing on the combination of modulation constellation diagrams with the Smith chart.

On Thursday, November 16, 2017, 15:00

Room 011, Kitot building

(The talk will be given in English)

Speaker:     Dr. Ilya Soloveychik
                   School of Engineering and Applied Sciences, Harvard University

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

Room 011, Kitot Bldg., Faculty of Engineering

Deterministic Random Matrices

Abstract

Random matrices have become a very active area of research in the recent years and have found enormous applications in modern mathematics, physics, engineering, biological modeling, and other fields. In this work, we focus on symmetric sign (+/-1) matrices (SSMs) that were originally utilized by Wigner to model the nuclei of heavy atoms in mid-50s. Assuming the entries of the upper triangular part to be independent +/-1 with equal probabilities, Wigner showed in his pioneering works that when the sizes of matrices grow, their empirical spectra converge to a non-random measure having a semicircular shape. Later, this fundamental result was improved and largely extended to more general families of matrices and finer spectral properties. In many physical phenomena, however, the entries of matrices exhibit significant correlations. At the same time, almost all available analytical tools heavily rely on the independence condition making the study of matrices with structure (dependencies) very challenging. The few existing works in this direction consider very specific setups and are limited by particular techniques, lacking a unified framework and tight information-theoretic bounds that would quantify the exact amount of structure that matrices may possess without affecting the limiting semicircular form of their spectra.

From a different perspective, in many applications one needs to simulate random objects. Generation of large random matrices requires very powerful sources of randomness due to the independence condition, the experiments are impossible to reproduce, and atypical or non-random looking outcomes may appear with positive probability. Reliable deterministic construction of SSMs with random-looking spectra and low algorithmic and computational complexity is of particular interest due to the natural correspondence of SSMs and undirected graphs, since the latter are extensively used in combinatorial and CS applications e.g. for the purposes of derandomization. Unfortunately, most of the existing constructions of pseudo-random graphs focus on the extreme eigenvalues and do not provide guarantees on the whole spectrum. In this work, using binary Golomb sequences, we propose a simple completely deterministic construction of circulant SSMs with spectra converging to the semicircular law with the same rate as in the original Wigner ensemble. We show that this construction has close to lowest possible algorithmic complexity and is very explicit. Essentially, the algorithm requires at most 2log(n) bits implying that the real amount of randomness conveyed by the semicircular property is quite small.