סמינר מחילקתי

More for Less: Adaptive Labeling Payment for Online Labor Markets”

Dr. Tomer Geva – faculty member, Coller School of Management, Tel Aviv University

Abstract:

Predictive modeling has emerged as integral to the efficient operations and competitive strategies of firms across industries. Because many important predictive tasks require human intelligence to label training instances, online crowdsourcing markets have become a promising platform for large-scale labeling. However, prior research found major quality issues in such markets. In particular, very different tradeoffs arise between payment offered to labelers and the quality of labeling under different settings, and, more broadly, work quality may change over time and with changes in the competitive market settings. Further, determining the effect of labeling quality on the expected improvement in predictive performance is also challenging. Therefore, effective means for dealing with these challenges are essential for a growing reliance on these markets for predictive modelling. In this paper, we propose the new data science problem of Adaptive Labeling Payment (ALP): how to determine and continuously adapt the payment offered to crowd workers, before they undertake a labeling task, so as to produce a given predictive performance cost-effectively. We develop an ALP framework and derive a novel ALP method, which we evaluate extensively over a wide variety of market conditions. We find that our ALP method yields substantial cost savings and robust performance that can be relied on by businesses over a wide variety of settings.

(Joint work with Harel Lustiger and Maytal Saar-Tsechansky)

ההרצאה תתקיים ביום שלישי, 28.03.17 בשעה 14:00 , בחדר 206, בניין וולפסון, הפקולטה להנדסה, אוניברסיטת תל-אביב.

28 במרץ 2017, 14:00

חדר 206 בניין וולפסון

סמינר מחלקתי - אלקטרוניקה פיזיקאלת עמיחי מאירי

30 במרץ 2017, 15:00

אוניברסיטת תל אביב פקולטה להנדסה ביניין כיתות חדר 011

סמינר מחלקתי - אלקטרוניקה פיזיקאלת עמיחי מאירי

You are invited to attend a lecture

Enhancing optical nanoscopy by point-spread-function
spatial modulation

By:

Amihai Meiri

Faculty of Engineering, Bar Ilan University.

Abstract

An optical microscope has a fundamental limit of resolution: the diffraction limit, approximately 200nm for visible light. Nanoscopy methods such as STED and PALM/STORM were developed to overcome this limitation, and are capable of optical imaging with a resolution of 20– 50nm. Localization microscopy methods (PALM/STORM and single particle tracking) rely on the ability to precisely find the position of a single point emitter, where the resolution depends directly on the precision of localization.
In this talk I will describe how spatial modulation of the signal coming from a microscope can improve the capability to localize single emitters, in particular for particle tracking applications using scattering objects such as metal nanoparticles. In addition, I will show how this technique may be applicable to incoherent point sources such as fluorescent probes. This solution allows for faster, higher resolution imaging with relatively simple and low cost means, and can be used with any optical microscope.

On Thursday, March 30, 2017, 15:00
Room 011, Kitot building

School of Mechanical Engineering Inna Horovitz

24 באפריל 2017, 14:00 - 15:00

בניין וולפסון חדר 206

School of Mechanical Engineering Inna Horovitz

School of Mechanical Engineering Seminar
Monday, April 24, 2017 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

Application of nano-structured solar photocatalytic membrane reactor for water treatment

Inna Horovitz

PhD Student of Prof. Hadas Mamane and Prof. Dror Avisar

Microfiltration (MF, with pores in the 0.1-10 μm range) systems offer quick and selective separation of suspended particles, larger pathogenic micro-organisms while operating at low transmembrane pressure. However, a number of contaminants, including micro-pollutants and viruses, can only be poorly removed from water by MF alone. Combining membrane filtration and advanced oxidation processes (AOP) as photocatalysis can potentially provide high water quality in a single step. Photocatalysis, which is classified as a heterogeneous AOP, is a process where a semiconductor (catalyst) is activated with sunlight irradiation following formation of highly oxidative species on the catalytic surface. A hybrid photocatalytic membrane reactor (PMR) can address multiple functions besides traditional physical separation as degradation of organic pollutants, disinfection and self-antibiofouling action. In this seminar, the efficiency of N-doped TiO₂-coated Al₂O₃MF membranes for water treatment will be presented. The photocatalytic activity (PCA) and the impact of physical and operational parameters such as operation mode (surface vs. in-pore PCA), wavelength dependence and flow rate of the suggested PMR will be presented by following the degradation of environmentally persistent pharmaceutical carbamazepine. Removal of MS2 bacteriophage, a surrogate for pathogenic waterborne viruses, by the PMR will be presented as a study case for disinfection efficiency. Virus removal in different water qualities will be addressed and correlated to the physico-chemical properties of the virus and the membrane.

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EE Seminar: No Equations, No Parameters, No Variables: Data-driven Geometry Learning for Parametrically-Dependent Dynamical Systems

(The talk will be given in English)

Speaker: Prof. Ronen Talmon,
Department of Electrical Engineering, Technion

Sunday, April 2^nd, 2017
15:00 - 16:00

Room 011, Kitot Bldg., Faculty of Engineering

No Equations, No Parameters, No Variables: Data-driven Geometry Learning for Parametrically-Dependent Dynamical Systems

Abstract

The extraction of models from data is a fundamental cognitive as well as scientific challenge. We demonstrate a geometric/analytic learning algorithm capable of creating minimal descriptions of parametrically-dependent unknown nonlinear dynamical systems. This is accomplished by the data-driven discovery of useful intrinsic state variables and parameters, in terms of which one can empirically model the underlying dynamics. We present an approach based on informed observation geometry that enables us to formulate models without first principles, as well as without closed-form equations. Our toolbox consists of data-driven hierarchical structures, multiscale bases and metrics, and intrinsic minimal data representations.

We will show applications to simulated data as well as to in-vivo recordings of neuronal activity from awake animals. The application of our technique to such recordings demonstrates its capability of capturing the relations between time-dependent neural activities in different cortical regions (motor and sensory) and associate them to behavior. Specifically, our approach gives rise to the joint organization of neurons and dynamic patterns in data-driven hierarchical structures, as well as to multi-resolution representations, discovering latent driving structures and connectivity patterns as they develop and vary over the course of weeks, days, and within individual trials. By jointly organizing neurons along time segments, our methodology reveals co-dependencies and patterns of activation related to external triggers (e.g., a tone) and behavioral events (e.g., the sequence of motor actions). In addition, we will discuss a preliminary attempt to relate the extracted model from the same animal at different stages of its training and to reveal a proficiency phase shift: from beginner through learner to expert.

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02 באפריל 2017, 15:00

חדר 011, בניין מעבדות-חשמל

סמינר מחלקתי - אלקטרוניקה פיזיקאלית - טלי דותן

22 במרץ 2017, 10:00

אוניברסיטת תל אביב בית ספר להנדסת חשמל ביניין וולפסון חדר 234

סמינר מחלקתי - אלקטרוניקה פיזיקאלית - טלי דותן

You are invited to attend a lecture

Precursor effects on Self-Assembled Monolayer (SAM) Cu Barrier Properties

for Sub-22 nm CMOS

By:
Tali Dotan

M.Sc student under supervision of Prof. Yosi Shacham-Diamand

Abstract
The purpose of this work was to study various Self Assembled Monolayers (SAM) as barrier layers in microelectronics. Recent reports have shown that organic Self Assembled monolayer (SAM) can be used as barrier layers against Cu diffusion for VLSI interconnect applications. In our work silanization was performed by chemical method from solutions, containing 1-2% silane in ethanol as a solvent. 7 different silanes were used and their barrier properties were measured using a "sandwich" Cu (100 nm)/SAM/Si structure. The barrier effectiveness was tested by vacuum annealing at the 200-500˚C range for periods up to 12 hours. Results reveal that N-[3-(Trimethoxysilyl)propyl]aniline and M-Aminophenyl-trimethoxysilane of the thickness of ~ 2 nm are the most effective and suitable barriers. They both have a head group of trimethoxy. One has a phenyl terminal group acting as a bulky barrier and the other an amino group that most likely forms Cu-N complex. XPS analysis is used to characterize the failure mechanism of the diffusion barriers and to validate the formation of copper silicide in the Cu/Si interface. Our results suggest that SAMs with appropriate terminal groups could be used to as barrier layer for in advanced ULSI interconnect technology. The method discussed in our work, using Cu/SAM/Si as a test structure is assumed to be predictive for the SAM effectiveness for Cu low-K metallization; however, this should be further tested.

On Wednesday, March 22, 2017, 10:00
Room 234, Wolfson building

סמינר מחלקתי ביה"ס להנדסה מכאנית Roee Finkelshtain and Slava Burkin

05 באפריל 2017, 14:00

וולפסון 206

סמינר מחלקתי ביה"ס להנדסה מכאנית Roee Finkelshtain and Slava Burkin

School of Mechanical Engineering Seminar
Thursday, April 5, 2017 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

Application of diffusive interface method to thermocapillary - driven flow of two immiscible fluids.

Viacheslav Burkin

M.Sc. Student of Prof. Alexander Gelfgat

A diffusive interface method was used to solve a problem of flow of two immiscible fluids driven by a thermocapillary force in a closed rectangular cavity. The traditional approach to this problem considers boundary conditions along the interface between two fluids, similar to those applied at physical boundaries of the volume: continuity of the viscous stresses and the heat flux.

Since boundaries between two liquids are usually curved, an accurate calculation of normal and tangent derivatives, needed for a straight-forward implementation of the boundary conditions, becomes a very complicated task. An alternative approach, that noticeably simplifies numerical model, is the volumetric approximation of the thermocapillary force. This approach assumes that fluids properties across the liquid-liquid interface change as a smoothed Heaviside function, while thermocapillary force is defined by a smeared delta-function. In current work we provide further enhancement of this method, by comparing different Heaviside functions by their accuracy relative to the known analytical solution, and adopt this method for computation of steady flow and analysis of their stability.

School of Mechanical Engineering Seminar
Wednesday, April 5, 2017 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

Ultrasonic yield assessment

Roee Finkelshtain

G. Kósa¹, Y. Yovel², A. Bechar³

Israel

¹School of Mechanical Engineering, Tel Aviv University (TAU), Israel

²Faculty of Life Sciences, TAU, Israel

³Institute of Agricultural Engineering, Agricultural Research Organization (ARO),

The spectrum of an ultrasonic return echo from plants has shown to contain information about them. This research focuses on developing an ultrasonic robotic sensing system, analyzing the ultrasonic classification features that would ultimately be used as the basis for a yield estimation robotic system, and developing an algorithm for prediction of fruit mass per plant based on the ultrasonic echoes returned from a plant. The ultrasonic sensor system was tested in a lab and pepper greenhouse environments and on single pepper plants, single leaves and fruit. The ultrasonic sensor system was integrated to a robotic platform and field experiments were conducted in a research pepper greenhouse. The results showed the potential of ultrasonic sensors for such a robot in classifying plants and greenhouse infrastructures, the ability to detect hidden plant rows and fruits as well as making an estimation of the fruit mass in single plants. A developed multi linear regression model for estimating the energy level was found to be highly significant with of and for to and to ranges respectively. The estimation accuracy is improved by mounting the sensing system on a monitoring robot and acquiring large plant-orientation sampling sets.

EE Seminar: Modeling and Learning Similarity of Shapes, Images and Signals

Speaker: Roee Litman

Ph.D. student under the supervision of Prof. Alex Bronstein

Monday, March 27^th, 2017 at 15:00
Room 011, Kitot Bldg., Faculty of Engineering

Modeling and Learning Similarity of Shapes, Images and Signals

Abstract

More than a decade ago, a major part of computer vision research was dedicated to engineering and designing the best way to capture meaningful features in images. So was the case in geometry processing and shape analysis. With time, the size of annotated datasets grew, also becoming more realistic and challenging. Together with the increase of low-cost computational power, this turned the focus of research more and more towards learning those features from the data themselves. While problem modeling is still a crucial part of research, learning-based methods are particularly successful whenever noise-invariance is harder to model, especially when the data are deviating from theory.

I will present several new methods and advances for the problem of measuring similarity and establishing correspondence between shapes, images and signals. The topics covered here progress from `designed' to `learned' in a gradual manner. First, there are some cases where the `right' model can solve the problem in a manner close to optimal, as shown for the problem of shape correspondence. Next, a model can be designed such that some small parts are allowed to adjust according to examples in order to improve performance, as shown in the case of shape descriptors. Finally, in some cases the model makes very mild assumptions and is almost completely learned from examples, as in the case of task specific sparse models.

27 במרץ 2017, 15:00

חדר 011, בניין כיתות-חשמל

Biomedical seminar

26 במרץ 2017, 14:30

מרב קטלוניה

תלמידת המחלקה להנדסה ביו רפואית לתואר שלישי תרצה בנושא:

Effect of Peripheral Electrical Stimulations on Glycemic Control Loop in Diabetes Patients

The epidemic nature of type 2 diabetes mellitus (T2DM), along with the downsides of current treatments, has raised the need for therapeutic alternatives. In this research we evaluated the effect of noninvasive peripheral electrical stimulation (PES) on glucose regulation in preclinical, and clinical pilot studies.

In a preclinical model, we studied normo-glycemic and high-fat diet (HFD), induced insulin-resistant rats for 3 weeks. In addition, the effect of an acute PES treatment on metabolic rates of glucose appearance and turnover was measured by using the hyperinsulinemic–euglycemic clamp test. This study demonstrates that a noninvasive PES treatment of very short duration in rats is sufficiently potent to stimulate glucose utilization, improve hepatic insulin sensitivity, and have a beneficial effect on body weight.

Then, a clinical study was designed to evaluate safety, tolerability, and the glucose-lowering effect of PES treatment in T2DM patients. Twelve patients were recruited for an open label, interventional, randomized trial, and underwent, in a crossover design, an active, and a no-intervention control trial periods. During the active period, the patients received a daily lower extremity PES treatment for 14 days. Endpoints were analyzed based on continuous glucose meter readings, and laboratory evaluation. The study results indicate that repeated PES treatment may suppress hepatic glucose production, and thus, act to maintain basal overnight and fasting glucose concentrations. This effect may be mediated, at least in part, by hypothalamic-pituitary-adrenal axis modulation.

Using mathematical model analysis of systemic glycemic control during nocturnal sleep, we explored possible neuroendocrine mechanisms involved in this therapeutic strategy.

Future studies, including larger populations, and longer follow up periods, are needed to gain better understating of these methods. Once proven over a larger cohort of patients, PES may provide an additional potential treatment strategy for the current solutions available for T2DM patients.

העבודה נעשתה בהנחיית ד"ר אורי נבו מהמחלקה להנדסה ביו-רפואית,

ופרופ' אשל בן-יעקב ז"ל מביה"ס לפיסיקה ואסטרונומיה, אוניברסיטת תל אביב

ההרצאה תתקיים ביום ראשון 26.03.17, בשעה 14:30

בחדר 315, הבניין הרב תחומי, אוניברסיטת תל אביב

Biomedical seminar

26 במרץ 2017, 15:00

Reverse Engineering Insect Flight

Dr. Gal Ribak

Department of Zoology, Faculty of Life Sciences, Tel Aviv University, Israel

Insect flight is the least understood type of aerial locomotion from both the biological and the physical perspectives. The high flapping frequency and relatively low Reynolds number lead to unique unsteady flow phenomena that insects have evolved to exploit during 350 million years of evolution. In my talk I will describe previous and current work carried out at my laboratory on insect flight biomechanics. By studying flight on all spatial, temporal and ecological levels we aim to reverse engineer insect flight, thus getting a true understanding of how nature’s miniature flyers work. The talk will touch on topics related to visual flight control, control of flight muscles, mechanical implications of body miniaturization and effect of wing flexural stiffness on flight performance and aerodynamics.

ההרצאה תתקיים ביום ראשון 26.03.17, בשעה 15:00

בחדר 315, הבניין הרב תחומי, אוניברסיטת תל אביב

סמינר מחלקתי- אלקטרוניקה פיזיקאלית ויטלי קוזלוב

20 במרץ 2017, 11:00

פקולטה להנדסה ביניין תוכנה קומה 5 חדר 512

סמינר מחלקתי- אלקטרוניקה פיזיקאלית ויטלי קוזלוב

~~You are invited to attend a lecture

ELECTROMAGNETIC SCATTERING GOVERNED BY MOVING SCATTERERS AND MAGNETO-ELECTRIC COUPLING
By:
Vitali Kozlov
M.Sc student under supervision of Dr. Pavel Ginzburg

Abstract
Contemporary commercial numerical tools, such as CST, Lumerical and COMSOL are commonly used to solve various electromagnetic, thermal and mechanical problems, to name a few. The above solutions are mostly designed for static problems – yet our world is not static. Scatterers move all the time, they may break into smaller pieces, collide to form bigger ones or otherwise change their shape or other scattering properties in time. To formulate the equations of EM scattering from such dynamic objects, velocities and accelerations must be included alongside the geometry of the objects when applying the boundary conditions of Maxwell’s equations.
This seminar deals with two topics, the first is the micro-Doppler shifts generated by a rotating wire. The wire is effectively a 1D object which makes it relatively simple to solve analytically, allowing physical insight into the phenomena. Intuitively one might expect that since various parts of the wire move at different speeds, the scattered field would have continuous Doppler shifts. Detailed analysis as well as experiments show that the scattered field has discrete frequencies only, forming a micro Doppler comb where the separation between the peaks is an integer multiple of the rotational frequency. The second part of the seminar is related to metamaterials, which have effective characteristics that are interesting for numerous applications in optics and RF, spanning from cloaking, solar cells, optical diodes and more. A hybrid magneto electric meta-atom is presented, made out of a straight wire and a split ring resonator with a unique property of asymmetric backscattering. This means that the meta-atom scatters radiation backwards differently depending on the direction of the incident field. Meta-atoms are the building blocks of metamaterials and it is expected that such meta-atoms could form new and exciting metamaterials with interesting properties.

On Monday, March 20, 2017, 11:00
Room 512, floor 5, Tohna building

Ultrasonic yield assessment

Reverse Engineering Insect Flight

Dr. Gal Ribak

עמודים