EE Seminar: Partial deformable shape correspondence

(The talk will be given in English)

 

Speaker:     Prof. Michael Bronstein
                      USI / TAU / Intel

 

Wednesday, November 2nd, 2016
15:00 - 16:00

Room 011, Kitot Bldg., Faculty of Engineering

 

Partial deformable shape correspondence

 

Abstract

Finding correspondence between 3D shapes is one of the prototypical problems in computer graphics, geometric processing, and vision. Different flavors of this problem arise in applications ranging from texture and animation to marker-less motion capture . The recent progress in the development of commercial real-time 3D scanning technology has brought the need for fast, accurate, and reliable correspondence methods capable of dealing with real-world noise and artifacts. Particularly hard settings of the correspondence problem include non-rigid correspondence (where the shapes are allowed to undergo deformations), partial correspondence (where a subset of the shape has to be matched to its deformed full version), and geometric and topological noise (the latter arising, for example, due to occluded parts in the acquisition process).

 

In this talk, I will show some recent results on computing partial correspondence between deformable shapes expressed in the spectral domain. Our main theoretical result is a perturbation analysis of the Laplacian operator, giving a bound on the change in its eigenvectors as a result of part removal. Based on this observation, we develop a generalization of functional maps capable of dealing with partial correspondence, clutter, and topological noise in very challenging settings.

 

(based on joint works with E. Rodola', L. Cosmo, J. Masci, A. Torsello, D. Cremers, O. Litany, A. Bronstein)

 

Bio

 

Michael Bronstein is an associate professor of Informatics at USI Lugano (Switzerland) and associate professor of Applied Mathematics at TAU. He is also a Principal Engineer at the Intel Perceptual Computing group. Michael got his Ph.D. in Computer Science (2007) from the Technion. His main research interests are theoretical and computational methods in spectral and metric geometry and their application to problems in computer vision, pattern recognition, computer graphics, and machine learning. His research appeared in international media and was recognized by numerous awards. In 2012, Michael received the highly competitive ERC starting grant. In 2014, he was invited as a Young Scientist to the World Economic Forum, an honor bestowed on forty world's leading scientists under the age of 40. Besides academic work, Michael is actively involved in the industry. He was the co-founder of the Silicon Valley start-up company Novafora, where he served as VP of technology (2006-2009), responsible for the development of algorithms for large-scale video analysis. He was one of the principal inventors and technologists at Invision, an Israeli startup developing 3D sensing technology acquired by Intel in 2012 and released under the RealSense brand. This technology can now be found in new generation computers from all the major brands.

 

02 בנובמבר 2016, 15:00 
חדר 011, בניין כיתות-חשמל  

EE Seminar: Faster Projection-free Machine Learning and Optimization

 (The talk will be given in English)

 

Speaker:     Dr. Dan Garber
                   Toyota Technological Institute at Chicago

 

 

Wednesday, November 9th, 2016
15:00 - 16:00

Room 011, Kitot Bldg., Faculty of Engineering

 

Faster Projection-free Machine Learning and Optimization

 

Abstract

Projected gradient descent (PGD), and its close variants, are often considered the methods of choice for solving a large variety of machine learning optimization problems, including empirical risk minimization, statistical learning, and online convex optimization. This is not surprising, since PGD is often optimal in a very appealing information-theoretic sense. However, for many problems PGD is infeasible both in theory and practice since each step requires to compute an orthogonal projection onto the feasible set. In many important cases, such as when the feasible set is a non-trivial polytope, or a convex surrogate for a low-rank structure, computing the projection is computationally inefficient in high-dimensional settings. An alternative is the conditional gradient method (CG), aka Frank-Wolfe algorithm, that replaces the expensive projection step with a linear optimization step over the feasible set. Indeed in many problems of interest, the linear optimization step admits much more efficient algorithms than the projection step, which is the reason to the substantial regained interest in this method in the past decade. On the downside, the convergence rates of the CG method often fall behind that of PGD and its variants.
In this talk I will survey an ongoing effort to design CG variants that on one hand enjoy the cheap iteration complexity of the original method, and on the other hand converge provably faster, and are applicable to a wider variety of machine learning settings. In particular I will focus on the cases in which the feasible set is either a polytope or a convex surrogate for low-rank matrices. Results will be demonstrated on applications including: LASSO, video co-localization, optical character recognition, matrix completion, and multi-class classification.

 

Bio

 

Dan's research interests lie in the intersection of machine learning and continuous optimization. Dan's main focus is on the development of efficient algorithms with novel and provable performance guarantees for machine learning, data analysis, decision making and optimization problems.
Dan is currently a Research Assistant Professor at Toyota Technological Institute at Chicago, a philanthropically endowed academic computer science institute located on the University of Chicago campus. Previously, he received both his Ph.D and his M.Sc degrees from the Technion - Israel Institute of Technology, where he worked under the supervision of Prof. Elad Hazan. Before that, Dan completed his bachelor's degree in electrical engineering, also in the Technion.
 

 

 

09 בנובמבר 2016, 15:00 
חדר 011, בניין כיתות-חשמל  

סמינר מחלקתי ביה"ס להנדסה מכאנית Prof. Greg Rodin

04 בינואר 2017, 14:00 
וולפסון 206  
0
סמינר מחלקתי ביה"ס להנדסה מכאנית Prof. Greg Rodin

 

 

 

 

School of Mechanical Engineering Seminar
Wednesday, January 4, 2016 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

 

 

ON ELASTIC INTERACTIONS WITHIN REPRESENTATIVE VOLUME ELEMENTS CONTAINING INHOMOGENEITIES

 

Prof. Gregory J. Rodin

Institute for Computational Engineering and Sciences

University of Texas at Austin

gjr@ices.utexas.edu

 

 

Interactions in linear elastic composites containing inhomogeneities are examined using integral equations. Two types of elastic interactions are identified: (i) many-body interactions among inhomogeneities and (ii) collective interactions between the entire population of inhomogeneities and the boundary data. It is shown that for large specimens the latter interactions can be expressed in terms of macroscopic quantities. A simple approximation for the effective stiffness tensor is developed by assuming that the many-body interactions among inhomogeneities are negligible. The new approximation coincides with the Mori-Tanaka approximation for basic cases, but should be more accurate in general, as it is based on a less restrictive assumption. An integral equation is also used to examine the underlying assumptions of the Kanaun-Levin and Ponte--Willis approximations. Connections with Maxwell's approximation are established.

 

 

 

 

 

סמינר מחלקתי ביה"ס להנדסה מכאנית Dr. Yaniv Edery

02 בינואר 2017, 14:00 
וולפסון 206  
0
סמינר מחלקתי ביה"ס להנדסה מכאנית Dr. Yaniv Edery

סמינר מחלקתי ביה"ס להנדסה מכאנית Sung Yung Kim

16 בינואר 2017, 14:00 
וולפסון 206  
0
סמינר מחלקתי ביה"ס להנדסה מכאנית Sung Yung Kim

 

 

 

 

School of Mechanical Engineering Seminar
Monday, January 16, 2017at 14:00
Wolfson Building of Mechanical Engineering, Room 206

 

 

Various aspects of coastal dynamics embedded in the observations of high-frequency radar-derived surface currents

 

Prof. Sung Yung Kim

                                    Department of Mechanical Engineering at Korea  

Abstract: The nearly completed U.S. West Coast (USWC) high-frequency radar (HFR) network provides an unprecedented capability to monitor and understand coastal ocean dynamics and phenomenology through hourly surface current measurements at up to 1 km resolution. The dynamics of the surface currents off the USWC are governed by tides, winds, Coriolis force, low-frequency pressure gradients (less than 0.4 cycles per day (cpd)), and nonlinear interactions of those forces. Alongshore surface currents show poleward propagating signals with phase speeds of O(10) and O(100 to 300) km/day and time scales of 2 to 3 weeks. The signals with slow phase speed are only observed in southern California. It is hypothesized that they are scattered and reflected by shoreline curvature and bathymetry change and do not penetrate north of Point Conception. The seasonal transition of alongshore surface circulation forced by upwelling-favorable winds and their relaxation is captured in fine detail. Submesoscale eddies, identified using flow geometry, have Rossby numbers of 0.1 to 3, diameters in the range of 10 to 60 km, and persistence for 2 to 12 days. The HFR surface currents resolve coastal surface ocean variability continuously across scales from submesoscale to mesoscale (O(1) km to O(1000) km). Their spectra decay with k-2 at high wave number (less than 100 km) in agreement with theoretical submesoscale spectra below the observational limits of present-day satellite ealtimeters.

Bio: Sung Yong Kim is an Assistant Professor in the Department of Mechanical Engineering at Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea and the director of the Environmental Fluid Mechanics Laboratory at KAIST. He received B.S. degree in Naval Architecture and Ocean Engineering from Seoul National University, Seoul, Republic of Korea, in 1999 and Ph.D. degree in Applied Ocean Science from Scripps Institution of Oceanography, La Jolla, USA, in 2009. His present research interests are in the areas of coastal circulation, sub-mesoscale processes, statistical and dynamical data analysis, environmental parameterization, and operational coastal ocean observing system. He has served as a member of Technical Committee (MONITOR) in the North Pacific Marine Science Organization (PICES) since 2014. He is the recipient of the Young Frontier Research Scientists Award in the Korean Academy of Science and Technology in 2013, the Young Scientist Award in the Korean Society of Oceanography in 2014, the Young Scientist Award to brighten Korea for next 30 years (selected as one of 30 persons in Natural Sciences) in 2016.
 

 

 

 

 

 

פרופ' נתן צבי שקד

סמינר מחלקתי ביה"ס להנדסה מכאנית Prof.Ytrehus

30 בנובמבר 2016, 15:00 
וולפסון 206  
0
סמינר מחלקתי ביה"ס להנדסה מכאנית Prof.Ytrehus

 

 

 

 

School of Mechanical Engineering Seminar
Wednesday, November 30, 2016 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

 

 

“MODELING ISSUES FOR SUBSEA GAS TRANSPORT PIPELINES”

 

Prof. Ytrehus

Professor Emeritus Tor Ytrehus

Department of Energy and Process Technology

Norwegian University of Science and Technology

 

 

The seminar will focus on fluid mechanics issues for subsea transport of gas in long export pipelines, with specific reference to the GASSCO1)-operated infrastructure between the coast of Norway and continental Europe and UK. Turbulent pipe-flow at high Reynolds numbers of the order of 107, and with pressure differences from 300 –to 20bar will be considered for pipelines of length up to 1000km. Computed results will be compared to “real life” situations for steady and transient flow events. Some attention to basic fluid mechanics elements, like details of the dissipation function in turbulent pipe flow, and consistent use of classical correlations for heat transfer, will be given along with some remarks on state equations for real gases.        

1) State owned operator of Norwegian gas transport infrastructure

 

 

 

 

 

 

סמינר מחלקתי ביה"ס להנדסה מכאנית Uri Brimam and Asaf Sharon

16 בנובמבר 2016, 15:00 
וולפסון 206  
סמינר מחלקתי ביה"ס להנדסה מכאנית Uri Brimam and Asaf Sharon

SCHOOL OF MECHANICAL ENGINEERING SEMINAR

Wednesday, November 16, 2016 at 15:00 Wolfson Building of Mechanical Engineering, Room 206

Dynamic Mechanical Analysis of Tubular Composite Joints: Rate Effects and Failure Prediction

Breiman Uri
MSc Student of Prof. Rami Haj-Ali

Bolted and welded connections are two common methods to join metallic parts. However, these are not viable or acceptable methods for parts made from composite materials. Bolted or riveted composites, for example, allow for local damage and delamination leading to reduced strength to weight ratio. One alternative, is to use thin adhesive layer between the joined composite parts. The mechanical behavior of such composite lap joints is strongly influenced by the adhesive layer and its elastic and strength properties as it becomes the weakest link. This dependency is pronounced in the case where joints are subjected to dynamic loading effects, especially when the polymeric layer is rate dependent.
The overall research goal was to analyze the dynamic rate behavior of polymeric materials used in composite structures. Specific goals were to investigate experimentally and computationally the polymeric mechanical behavior influence on tubular composite joints. Towards these goals, computational finite-element (FE) method was used to generate FE models at the structural level. The high fidelity generalized method of cells (HFGMC) was also employed to generate the effective linear response of the layered composite adherents. Experimental tests of the polymeric and composite material systems were also performed using digital image correlation (DIC), as well as strain gage (SG) measurement. A new rate-dependent constitutive failure model was also calibrated for the dynamic mechanical behavior of the epoxy material. Finally, the proposed rate-dependent material model along with the global FE tubular composite joint models are compared with uniaxial dynamic tensile tests.

 

 

 

 

 

School of Mechanical Engineering SeminarSchool of Mechanical Engineering Seminar

Wednesday, Nov 16, 2016 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

 

Advanced Controlled Cryogenic Ablation Using Ultrasonic Sensing System

Assaf Sharon

MSc. Student of Dr. Gabor Kosa

 

Cryoablation process is one of the methods for treating various tissue abnormities. Cryoablation devices are mostly minimally invasive and are used in open loop control, monitored by additional imaging devices. In this study, we monitor the growth of the ablated area by using a miniature ultrasonic transducer that is collocated with the tip of the cryogenic device. The 10-20 MHz ultrasonic sensor is capable of measuring the size of the ice sphere that is created in front of the needle. The measurement is done within the ice sphere. In addition to real time monitoring of the ablation process, the ultrasonic sensor will be able to determine the local thickness of the tissue prior to the treatment (thus enabling the setting of the power of the ablation treatment). The combined device will shorten the ablation treatment and will eliminate the need for additional ablation treatments or monitoring devices. The proof of concept was done in water, ultrasonic gel and breast tissue. In the experiments we found that, in the frequency domain one can identify at 10-12 MHz frequency range, the increase of the intensity of the returned echo in the ice and the decrease of the signal after the ice-tissue boundary. The intensity represents the overall power returning to the sensor from the medium in front of it. One can correlate the increase of the intensity with the growth of the ice sphere. We created a software, calibrated by our initial experiments, which receives as an input the requested ice ball size to reach and returns a ‘stop’ pop up message in real time when the requested ice ball size is reached with 0.3 mm accuracy.

 

ADVANCES IN PRESSURE CARE AWARD על ידי כתב-העת החשוב Journal of Wound Care

10 אוקטובר 2016
ברכות חמות לפרופ' עמית גפן על קבלת פרס קריירה

כנס איחוד האיגודים הבינלאומיים לריפוי וטיפול בפצעים הוא כנס גדול ומרכזי הנערך אחת לארבע שנים ומושך אלפי חוקרים, מדענים, קלינאים ותעשייה. השנה נערך הכנס בפירנצה איטליה. הנהלת הכנס ואיחוד האיגודים הבינלאומיים, יחד עם כתב-העת החשוב בתחום Journal of Wound Care, החליטה להעניק את פרס הקריירה -

ADVANCES IN PRESSURE CARE AWARD

לפרופ' עמית גפן מהמחלקה להנדסה ביו-רפואית על תרומתו המדעית להבנת האטיולוגיה של פצעי לחץ ואסטרטגיות לפיתוח טכנולוגיות למניעת פצעי לחץ באוכלוסיות שונות, בפרט בנפגעי חוט שדרה, בחולים מבוגרים ובילדים/פגים.

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