הפקולטה להנדסה ע"ש איבי ואלדר פליישמן

סמינר מחלקתי - נטע רגר וילנה פטריקינה

17 במאי 2016, 14:00

בניין וולפסון חדר 206

Department of Materials Science and Engineering - Special Seminar

Looking for Atoms at Complex Interfaces

Professor Michael Bedzyk

Department of Materials Science and Engineering, Northwestern University

23 במאי 2016, 14:00

Room 130, Wolfson Mechanical Engineering Building

Department of Materials Science and Engineering - Special Seminar

Looking for Atoms at Complex Interfaces

Farkash Elad סמינר מחלקתי ביה"ס להנדסה מכאנית

25 במאי 2016, 15:00

וולפסון 206

Farkash Elad סמינר מחלקתי ביה"ס להנדסה מכאנית

School of Mechanical Engineering Seminar
Wednesday, May 25, 2016 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

Reassessment of the Virtual Crack Closure Technique for Interface Cracks

Elad Farkash

Supervisor: Prof. Banks-Sills

The Virtual Crack Closure Technique (VCCT) was first presented in 1977 for cracks in linear elastic, homogeneous and isotropic material. It makes use of the Irwin crack closure integral to obtain values of the modes I, II and III energy release rates from finite element data. It can easily be extended to anisotropic material. In addition, it was extended to cracks along an interface between two dissimilar linear elastic, homogeneous and isotropic materials and two dissimilar anisotropic materials. In those cases, the energy release rates were seen to depend upon the size of the virtual crack extension usually taken as the size of the element adjacent to the crack tip. Some attempts have been made to remove this dependence. Nevertheless, in most cases, the accuracy of both the energy release rates and stress intensity factors was not consistently good.

In this work, the dependence of the energy release rates on the size of the virtual crack extension for interface cracks between two dissimilar isotropic and two dissimilar anisotropic materials is analytically accounted for so that the stress intensity factors may be accurately obtained when fine finite element meshes are used, together with a virtual crack extension consisting of more than one element. Results from some example problems will be presented.

15 מאי 2016

Avshalom Sheffer and Raz Shraga סמינר מחלקתי ביה"ס להנדסה מכאנית

08 ביוני 2016, 15:00

וולפסון 206

Avshalom Sheffer and Raz Shraga סמינר מחלקתי ביה"ס להנדסה מכאנית

EE Seminar: Full 3D Plant Reconstruction via Intrusive Acquisition

~~Speaker: Alexei Gaissinski,
M.Sc. student under the supervision of Prof. Andrei Sharf and Prof. Shai Avidan

Wednesday, May 18, 2016 at 15:00
Room 011, Kitot Bldg., Faculty of Engineering

Full 3D Plant Reconstruction via Intrusive Acquisition
Abstract
Digitally capturing vegetation using off-the-shelf scanners is a challenging problem. Plants typically consist of large self-occlusions and thin structures which cannot be properly scanned. Furthermore, plants are essentially dynamic, rendering small deformations in time, which yield additional difficulties in the scanning process.
In this thesis we present a novel technique for acquiring and modeling of plants and foliage. At the core of our method is an intrusive acquisition approach, which disassembles the plant into disjoint parts that can be accurately scanned and reconstructed offline. We use the reconstructed part meshes as 3D proxies for the reconstruction of the complete plant and devise a global-to-local non-rigid registration technique that preserves specific plant characteristics.
Our method is tested on plants of various styles, appearances, and characteristics. Results show successful reconstructions with high accuracy with respect to the acquired data.

18 במאי 2016, 15:00

חדר 011, בניין כיתות-חשמל

הכנס השנתי שך IAP

18 במאי 2016, 10:00

כנס השנתי שלנו ב-18 במאי בבניין פורטר. מחכות לכם 3 שעות מעניינות. הרשמה אצל יערית, על ידי שליחת אימייל ל- yaaritr@tauex.tau.ac.il

05 מאי 2016

EE Seminar: Puncturing, Expurgating and Expanding the q-ary BCH Based Robust Codes

~~
Speaker: Nir Admaty
M.Sc. student under the supervision of Prof. Simon Litsyn

Wednesday, June 1st, 2016 at 15:30
Room 011, Kitot Bldg., Faculty of Engineering

Puncturing, Expurgating and Expanding the q-ary BCH Based Robust Codes

Abstract

A code that can detect errors with high probability is called a security oriented code. A security oriented code that can detect any non-zero error is called robust. A BCH based robust code is a code that is based on the columns of the check matrix of a linear BCH code. The non-binary BCH based robust code is derived from the one-error-correcting BCH code. The binary BCH based robust code is derived from the two-error-correcting BCH code. The undetected error probability Q(e) of an error e is determined by the set of codewords that mask e. The maximal error masking probability is denoted by Q ̅. A robust code is said to be optimum if there is no other code with a larger number of codewords with the same length and the same Q ̅.

The thesis presents four constructions for optimum and nearly optimum robust codes that are based on modifications of the BCH based robust codes. In particular, they generalize, puncture, expurgate, and expand the codes while preserving their robustness.

The generalized codes are a class of codes from which the BCH based code is derived. When puncturing, u redundancy symbols are deleted from the code. When expurgating, codewords which have the same value in u predefined redundancy symbol positions are grouped together and these u redundancy symbols are deleted. When expanding, a new robust code is constructed by fusing two robust codes.

The generalized and punctured codes have Q ̅ which is a power of q (the field alphabet size), and the expurgated and expanded code have Q ̅ which is not a power of q. The generalized code has a fixed code rate which is half. However, the other three constructions can increase the robust BCH based code rate while preserving its robustness.

01 ביוני 2016, 15:30

חדר 011, בניין כיתות-חשמל

Raphael Stuhlmeier סמינר מחלקתי ביה"ס להנדסה מכאנית

16 במאי 2016, 15:00

וולפסון 206

Raphael Stuhlmeier סמינר מחלקתי ביה"ס להנדסה מכאנית

School of Mechanical Engineering Seminar
Monday, May 16, 2016 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

Havelock's theory for acoustic-gravity waves in deep water

Raphael Stuhlmeier

PhD in Mathematics at the University of Vienna

In this talk, we will investigate the linearized theorey of waves generated by a wave-maker in compressible flow. In addition to the propagating and evanescent waves found in the incompressible case, new modes then appear which incorporate both the effects of gravity and compressibility - called acoustic-gravity waves. The treatment of this problem in infinite depth is an exercise in classical analysis, and leads to a version of Havelock's wave-maker theorem for compressible flows. We shall discuss the asymptotic behavior of these new waves, give some simple examples for line wave-makers, and look briefly at some related problems and open questions.

Short Bio:

Raphael Stuhlmeier completed a PhD in Mathematics at the University of Vienna, Austria in 2014, treating primarily nonlinear water waves with vorticity, including extensions of Gerstner waves and solitary waves on shear flows. Since then, he has been a Postdoctoral Fellow at the Faculty of Civil & Environmental Engineering, Technion - Israel Institute of Technology, working primarily on the theoretical basis for wave-power harvesting in the open seas, and occasionally on other topics in water waves.

לעמית גפן ולסטודנט יורם זאראי

ברכות לסטודנט אייל תאומי (דוקטורנט של יאיר שוקף מהנדסה מכנית) על זכייה במלגת דן-דויד היוקרתית. 2 סטודנטים מהפקולטה (גם רועי רמז) הם בין 7 הזוכים מכל העולם.

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