הפקולטה להנדסה ע"ש איבי ואלדר פליישמן

18.10.15

18 באוקטובר 2015, 14:00

011 Kitot

You are invited to attend a lecture

By:

Dr. Rita Schmidt

Leiden University Medical Center

High dielectric materials in 7 T human MRI: New dielectric resonator designs, shaped materials (e.g. pre-fractal) for improved transmit field homogeneity, and imaging of electrical properties of tissue

Abstract

Magnetic resonance Imaging and spectroscopy (MRI and MRS) are important diagnostically as well as being contemporary research tools for the study of biological tissue. Human MRI at ultra-high fields (>4 T) is a new fascinating direction in research, with advantages including higher signal-to-noise ratio (SNR), increased spectral resolution, and much greater magnetic susceptibility induced tissue contrast. However, one of the main challenges for MRI at these very high magnetic fields is the significant inhomogeneity of the transmit radio frequency (RF) magnetic field. This is due to constructive and destructive wavelength effects, as the wavelength is comparable to the dimensions of the object being imaged.

My research explores methods to overcome these challenges through the use of high permittivity dielectric materials; turning the wave like interference “weakness” into strength. Exploring the effects of these materials in the vicinity of regions of interest has shown both local increase and severe decrease in RF field intensity. Shaping the materials with holes (e.g. pre-fractal arrangement) can manipulate the magnetic and electric fields and improve the local and global RF field intensity. Also, new dielectric resonators having high Q factor values with the required electromagnetic modes can be built; for example using just water. Combining these new resonators with traveling wave antenna enables a new simple implementation for dual-nuclei imaging (protons and phosphorous nucleus, for example). Finally, by changing the magnetic and electric field using these dielectric materials, one can solve an inverse problem, using the Maxwell equations in their integral representations, and so reconstruct the electrical properties fingerprint of biological tissue, which is a new MRI contrast containing important physiological information.

Bio

Rita Schmidt received her B.Sc. in Physics at the Tel-Aviv University in 2000 and her M.Sc. in Medical Physics from the Tel-Aviv University in 2005. During her M.Sc. research and until 2010 she worked in the industry. Her positions included Research Physicist and Lead System Engineer in a company developing Focused Ultrasound devices with MRI guidance for non-invasive therapy. In 2014 she received a PhD from the Weizmann Institute, where she developed new methods for rapid imaging methods. She is currently a postdoctoral fellow in the Department of Radiology at the Leiden University Medical Center, and her research focuses on a deeper understanding of electromagnetic radiation in biological tissue in the presence of ultra-high magnetic field.

Sunday, October 18, 2015, at 14:00

Room 011, Kitot building

היום הראשון ללימודים (1)

	30.10.2016	יום א' כ"ח בתשרי
חופשת חנוכה (2)	25.12.2016	יום א', כ"ה בכסלו
היום האחרון לסמסטר הראשון *	29.1.2017	יום א', ב' בשבט
יום פתוח	3.2.2017	יום ו',ז' בשבט
פורים (3)	12.3.17	יום א', י"ד באדר
היום הראשון לסמסטר השני	13.3.17	יום ב', ט"ו באדר
יום לימוד חלופי – לקורסי יום ג' בסמסטר ב' ויום אחרון לפני חופשת הפסח	5.4.17	יום ד', ט' בניסן
היום הראשון ללימודים לאחר חופשת פסח	19.4.17	יום ד', כ"ג' בניסן
יום הזיכרון לחללי מערכות ישראל (3) (5)	1.5.17	יום ב', ב' באייר
יום העצמאות (3)	2.5.17	יום ג', ו' באייר
יום הסטודנט (6)	25.5.17	יום ה', כ"ט באייר
חופשת שבועות (3)	30-31.5.17	יום ג'-ד', ה'-ו' בסיון
היום האחרון לסמסטר השני	29.6.17	יום ה', ה' בתמוז
היום הראשון לעונת לימודי הקיץ	23.7.17	יום א', כ"ט בתמוז
צום ט' באב (3)	1.8.17	יום ג', ט' באב
היום האחרון לעונת לימודי הקיץ	15.9.17	יום ו', כ"ד באלול
חופשת הקיץ המרוכזת (5)	מ-27.8.17 עד-1.9.17	יום א', ה' באלול יום ו', י' באלול
טקסי זיכרון - בימים אלה יופסקו הלימודים לשעה אחת, בין 13:00-12:00
עצרת לזכרו של יצחק רבין ז"ל	13.11.16	יום א', י"ב בחשון
טקס יום השואה (4)	24.4.17	יום ב', כ"ח בניסן
טקס יום הזיכרון לחללי מערכות ישראל (5)	30.4.17	יום א', ד' באייר
היום הראשון ללימודים בשנת תשע"ח 2017/18	22.10.17	יום א', ב' בחשון
תקופת בחינות סמסטר א': מיום ב' 30.1.17 ג' בשבט, עד יום ו' 10.3.17 י"ב באדר

1. בפקולטה לרפואה עשוי מועד תחילת הלימודים להיות שונה. בתכניות לתארים מתקדמים בפקולטה לניהול ייתכנו שינויים, יש להתעדכן באתר הפקולטה.

2. חופשת חנוכה ובחינות פסיכומטריות

3. בימים אלה לא מתקיימת כל פעילות באוניברסיטה.

4. בערב יום הזיכרון לשואה והגבורה (23.4.17 כ"ז בניסן) יסתיימו הלימודים בשעה 19.00

5. בערב יום הזיכרון לחללי מערכות ישראל ( 30.4.17 ד' באייר) יסתיימו הלימודים בשעה 18.00.

6. ביום הסטודנט הלימודים מסתיימים בשעה 12.00.

תלמידים רשאים להיעדר בהתאם לרשימת החגים של עדותיהם ולאחר שיעדכנו מראש את מזכירויות החוגים. כמו כן אם יתקיימו מבחנים בקורסי חובה במועדים שלהלן יהיו תלמידים אלה זכאים להיבחן במועד מיוחד:

יוצאי אתיופיה: חג הסיגד 30.11.16
מוסלמים וצ'רקסים: עיד אל פיטר 25-27.6.17; עיד אל אדחא (חג הקורבן) 1-4.9.17
דרוזים: עיד אל אדחא 1-4.9.17; חג הנביא שועייב 25-27.4.17
נוצרים: חג המולד 24-25.12.16; חג הפסחא 16.4.17

תלמידים הצמים בימי צום ותענית או במהלך חודש צום הרמדאן (27.5.17-25.6.17) זכאים למועדים מיוחדים במבחנים בקורסי חובה, המתחילים לאחר השעה 12.00

הכינוס המחקרי ה-7 להנדסת תעשיה וניהול 23 לפברואר, 2016

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קרא עוד אודות הכינוס המחקרי ה-7 להנדסת תעשיה וניהול 23 לפברואר, 2016

מסיבת פתיחת שנה - שנה א ' הנדסה מכנית

15 באוקטובר 2015, 10:44

סמינר מחלקתי

Dominating induced matchings in graphs containing no long claw

Alain Hertz
Polytechnique Montréal, Canada

(Coauthors : V. Lozin, B. Ries, V. Zamaraev, D. de Werra)

Abstract:

An induced matching M in a graph G is dominating if every edge not in M shares exactly one vertex with an edge in M. The dominating induced matching problem (also known as efficient edge domination) asks whether a graph G contains a dominating induced matching. This problem is generally NP-complete, but polynomial-time solvable for graphs with some special properties. In particular, it is solvable in polynomial time for claw-free graphs.

We study this problem for graphs containing no long claw, i.e. no induced subgraph obtained from the claw by subdividing each of its edges exactly once. To solve the problem in this class, we reduce it to the following question: given a graph G and a subset of its vertices, does G contain a matching saturating all vertices of the subset? We show that this question can be answered in polynomial time, thus providing a polynomial-time algorithm to solve the dominating induced matching problem for graphs containing no long claw.

Bio :

Holder of a diploma in Mathematical Engineering, Alain Hertz obtained a Ph.D in operations research at the École Polytechnqiue Fédérale de Lausanne. Since 2001, he is professor at the department of mathematics and industrial engineering at the École Polytechnique in Montréal. He is also member of the multi disciplinary GERAD research group that includes nearly sixty researchers and experts in operations research and discrete mathematics.

He is the author of about 180 scientific publications His main research domains are combinatorial optimization, graph theory, algorithmics, and the development of decision aid systems for scheduling and distribution problems.

ההרצאה תתקיים ביום שלישי 20.10.15, בשעה 14:00 בחדר 206, בנין וולפסון הנדסה, הפקולטה להנדסה, אוניברסיטת תל-אביב.

20 באוקטובר 2015, 14:00

חדר 206 בניין וולפסון

ארועים לסטודנטים

קרא עוד אודות ארועים לסטודנטים

EE Seminar: The Ribosome Flow Model: Theory and Applications

~~
Speaker: Yoram Zarai
Ph.D. student under the supervision of Prof. Michael Margaliot

Wednesday, November 25th, 2015 at 15:00
Room 011, Kitot Bldg., Faculty of Engineering

The Ribosome Flow Model: Theory and Applications

Abstract
Gene expression is the process by which information encoded in the genes is transformed into proteins. Protein synthesis begins with the transcription of the genetic information from DNA to mRNA, and proceeds to translation of the mRNA to proteins. During translation, molecular machines called ribosomes move along the mRNA chain, decoding triplets of mRNA nucleotides (called codons) into a chain of amino acids that is then folded into a protein. The translation process occurs in all organisms, in all known cells and in almost all conditions. Thus, understanding translation has important implications in many scientific disciplines, including medicine, biotechnology, and synthetic biology.

The Ribosome Flow Model (RFM) is a deterministic mathematical model for the flow of ribosomes along the mRNA chain. It consists of first-order, nonlinear ordinary differential equations, and parameters: the initiation rate and elongation rates , , between the consecutive sites. The RFM can be derived as a mean-field approximation of an important model from non-equilibrium statistical physics called the Totally Asymmetric Simple Exclusion Process (TASEP).

In this work, we study the RFM using tools from systems and control theory including contraction theory, monotone dynamical systems theory, the analytic theory of continued fractions, controllability and accessibility theory, and convex analysis.

We detail several biological implications of the analysis, provide examples of applications of the RFM other than translation, and discuss several possible directions for future research.

25 בנובמבר 2015, 15:00

חדר 011, בניין כיתות-חשמל

סמינר מחלקתי Prof. Do Kyung Kim

19 באוקטובר 2015, 15:00

School of Mechanical Engineering Seminar
Monday, October 19, 2015 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

Design, Synthesis and Electrochemical Characterizations of Electrode Materials for Rechargeable Na Ion Batteries

Do Kyung Kim

Professor, Department of Materials Science and Engineering

Dean, Office of Academic Affairs

KAIST (Korea Advanced Institute of Science and Technology),

Daejeon, Republic of Korea

(dkkim@kaist.ac.kr, http://mse2.kaist.ac.kr/~ncrl)

Although lithium ion rechargeable batteries are dominant the mobile devices and electric vehicles in the present, there are still some limitations in terms of cost and lithium reserves in the world. In that sense, interests on Na-based electrode materials have been revisited due to the abundance and low cost of sodium in recent years. I will present some of our recent efforts to make Na electrode materials have good electrochemical performance, as well as new materials with a distinctive structure. In first in the talk, I will discuss the structural and electrochemical properties of Na0.44MnO2, which is one of the promising cathode materials for Na ion batteries, in both aqueous and nonaqueous electrolytes. In search of other materials similar to Na0.44MnO2 to understand and verify the electrochemical properties of one-dimensional (1-D) tunnel structures, a new sodium ion intercalation material, Na2.7Ru4O9 with a similar 1-D tunnel structure to, but different polyhedral networks from, that of Na0.44MnO2, will be introduced. In addition, I will also introduce a simple synthetic approach to anchor materials on reduced graphene oxide surfaces to overcome the rate problems of Na-based electrode materials. Na3V2(PO4)3 with NASICON structure have been grown on graphene surface and this composite exhibits superior capacity retention at high rates and excellent cycleability. In the last part of talk, our recent works on Na2FeP2O7 cathode for aqueous Na-ion battery will be presented.

Biography (Do Kyung Kim)

Kim joined the faculty of Department of Materials Science and Engineering, KAIST in 1994. He received his B.S.degree from Seoul National University in 1982 and earned M.S. and Ph.D. from Department of Materials Science and Engineering of KAIST in 1984 and 1987, respectively. Before joining KAIST, he worked for the Agency for Defense Development(1987-1994), Korea. He had spent several visiting professor positions in UC San Diego(1992), NIST(2002), and UC Berkeley(2008). He was awarded a Top 20 Most Outstanding Research Award from Korea Science and Engineering Foundation (KOSEF) in 1997 and Top Most Outstanding Research Award from Korea Research Foundation (KRF) in 2011. His work also was selected as KAIST Top 10 Research in 2012. He has authored more than 150 technical articles, and has filled 17 Patents in US, Japan and Korea. Recently, he has been selected as a Fellow of the American Ceramic Society.

סמינר מחלקתי Shai Ly Shohat and Barak Even Hen

18 בנובמבר 2015, 15:00

וולפסון 206

סמינר מחלקתי Shai Ly Shohat and Barak Even Hen

School of Mechanical Engineering Seminar
Wednesday, November 18, 2015 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

THE EFFECT OF AORTIC VALVE REPLACEMENT ON THE CORONARY PERFUSION - COMPUTATIONAL FLUID-STRUCTURE INTERACTION MODELING AND ANALYSIS

Shaily Wald Shohat

MSc Student of Prof. Alex Liberzon & Prof. Idit Avrahami

In this study, we examine the impact of replacement valve on the coronary perfusion and on the pressure changes in the aortic root, compared with an intact valve. The numerical models include 2D computational fluid-structure interaction (FSI) simulation of the aortic root including the valve's leaflets and coronary arteries, using the commercial finite-element package of ADINA.

The study considered healthy, stenosed and TAVI valves. Pressure and flow patterns at different cardiac output (flow rate) and heart rates (beats per minute) were studied in details. It is found that aortic valve replacement leads to a significant improve in coronary perfusion pressure as well as in the cardiac cycle time. This could be explained by two potential mechanisms: (1) increase of the pressure gradient across the sinus due to induced diastolic vortical flow patterns, and (2) the high velocity ejection of blood into the aorta is reduced, thus reducing any existing Venturi effect on pressures in the sinus. The results may shed light on the dynamic mechanisms that affect coronary perfusion due to TAVI.

School of Mechanical Engineering Seminar
Wednesday, November 18, 2015 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

THE EFFECT OF AORTIC VALVE REPLACEMENT

ON THE CORONARY PERFUSION - EXPERIMENTAL STUDY

Barak Even Chen

MSc Student of Prof. Alex Liberzon & Prof. Idit Avrahami

Transcatheter aortic valve implantation (TAVI) is an alternative treatment to conventional surgical aortic valve replacement for patients with aortic stenosis. Patients with severe aortic stenosis suffer also from diastolic dysfunction and reduced coronary flow (perfusion). The coronary perfusion depends on the pressure gradient between the myocardial tissue during diastole and the coronary origin located at the aortic root (sinuses of Valsalva), and thus subjected to changes in diastolic flow field near the closing valve's leaflets. Coronary perfusion can be influenced by the valve size and design as well as diastolic time. It is suggested that TAVI improves coronary perfusion pressure and increases coronary flow-rate by two potential mechanisms: (1) increase of the pressure gradient across the sinus due to induced diastolic vortical flow patterns, and (2) the high velocity ejection of blood into the aorta is reduced, thus reducing any existing Venturi effect on pressures in the sinus.

In this experimental study, we examine the impact of replacement valve on the coronary perfusion and on the pressure changes in the aortic root, compared with an intact valve. The method is based on flow visualization in a transparent flexible model of the aortic root, along with the pressure and flowrate measurements to coronary arteries. The flow is driven by hemodynamic pump using pulse duplicator, and contains a synchronized controlled resistance in the coronary arteries.

The study considered healthy, stenosed and TAVI valves. Pressure and flow patterns at different cardiac output (flow rate) and heart rates (beats per minute) were investigated. The experimental results confirm that aortic valve replacement leads to normalization of coronary flow, although at slightly different rate as compared to the reference healthy case.

EE Seminar: Fronthaul Compression for Cloud Radio Access Networks: An Information Theoretic View

~~(The talk will be given in English)

Speaker: Prof. Shlomo Shamai
EE, Technion

Monday, November 9th, 2015
15:00 - 16:00
Room 011, Kitot Bldg., Faculty of Engineering
Fronthaul Compression for Cloud Radio Access Networks: An Information Theoretic View
Abstract
Cloud radio access networks (C-RANs) emerge as appealing architectures for next-generation wireless/cellular systems whereby the processing/decoding is migrated from the local base-stations/radio units (RU) to a control/central units (CU) in the "cloud".
This is facilitated by fronthaul links connecting the RUs to the managing CUs. We focus on oblivious processing at the RU, and hence the fronthaul links carry digital information about the baseband signals, in the uplink from the RUs to the CU and vice versa in the downlink. The high data rate service demands in C-RANs, imply that even with fast (optical) fronthauls, let alone for heterogeneous fronhauls, efficient compression of the basedand signals is essential.
In this talk we focus on advanced robust signal processing solutions, emerging by network information theoretic concepts, and review also the basic approaches to this cloud network.
Multi-hop fronthaul topologies are also discussed.
Analysis and numerical results illustrate the considerable
performance gains to be expected for different cellular models.
Some interesting theoretical directions conclude the presentation.
----------------------------------------------------------------
Joint work with S.-H. Park, O. Simeone (NJIT), and O. Sahin (InterDigital)

09 בנובמבר 2015, 15:00

חדר 011, בניין כיתות חשמל

עמודים