קולוקוויום וסמינרים

כדי להצטרף לרשימת תפוצה של קולוקוויום מדעי המחשב, אנא בקר בדף מנויים של הרשימה.


Computer Science events calendar in HTTP ICS format for of Google calendars, and for Outlook.

Academic Calendar at Technion site.

קולוקוויום וסמינרים בקרוב

  • Coding Theory: A Brief Introduction to Lattice Coding Theory

    דובר:
    בריאן קורקוסקי (מכון טכנולוגי, יפן)
    תאריך:
    יום ראשון, 4.6.2017, 14:30
    מקום:
    טאוב 601

    Lattices are error-correcting codes defined over the real numbers. In the physical world, 1 plus 1 is 2, and it is the same for lattices. An important example of a physical-world application is wireless communications. Two electromagnetic signals, transmitted at the same time, will superimpose --- that is, they add, making lattice codes a natural fit for wireless communications. This lecture gives a brief introduction to lattices for those already familiar with the fundamentals of coding theory. Similarities with finite-field codes, such as minimum distance, matrix representation and constructions are emphasized, while unique aspects of lattices such as scaling, Voronoi regions and nested lattice codes are explained. Some recent trends and open problems in lattice coding will be reviewed.

  • סדנת המרכז להנדסת מחשבים ע"ש סטפן ושרון זיידן 2017

    TCE Workshop: 2017 Stephen and Sharon Seiden Frontiers in Engineering and Science

    תאריך:
    יום שני, 5.6.2017, 09:30
    מקום:
    המרכז להנדסת מחשבים,טכניון

    הנכם מוזמנים לסדנת המרכז להנדסת מחשבים ע"ש סטפן ושרון זיידן 2017 של המרכז להנדסת מחשבים בנושא:
    "Beyond CMOS: From Devices to Systems" אשר תתקיים בימים שני-שלישי, 5-6 ביוני, 2017 בטכניון.
    ההרשמה תיפתח ב-15 במרס, 2017, ופרטים נוספים בדף האנגלי ובאתר הסדנה.

  • CGGC Seminar: Design of 3D printed mathematical art

    דובר:
    הנרי סגרמן (אונ' אוקלהומה סטייט)
    תאריך:
    יום שני, 5.6.2017, 13:30
    מקום:
    חדר 337, בניין טאוב למדעי המחשב

    When visualising topological objects via 3D printing, we need a three-dimensional geometric representation of the object. There are approximately three broad strategies for doing this: "Manual" - using whatever design software is available to build the object by hand; "Parametric/Implicit" - generating the desired geometry using a parametrisation or implicit description of the object; and "Iterative" - numerically solving an optimisation problem.

    The manual strategy is unlikely to produce good results unless the subject is very simple. In general, if there is a reasonably canonical geometric structure on the topological object, then we hope to be able to produce a parametrisation of it. However, in many cases this seems to be impossible and some form of iterative method is the best we can do. Within the parametric setting, there are still better and worse ways to proceed. For example, a geometric representation should demonstrate as many of the symmetries of the object as possible. There are similar issues in making three-dimensional representations of higher dimensional objects. I will discuss these matters with many examples, including visualisation of four-dimensional polytopes (using orthogonal versus stereographic projection) and Seifert surfaces (comparing my work with Saul Schleimer with Jack van Wijk's iterative techniques).

    I will also describe some computational problems that have come up in my 3D printed work, including the design of 3D printed mobiles (joint work with Marco Mahler), "Triple gear" and a visualisation of the Klein Quartic (joint work with Saul Schleimer), and hinged surfaces with negative curvature (joint work with Geoffrey Irving).

  • How to Find Cryptographic Needles In Exponentially Large Haystacks

    דובר:
    Adi Shamir - COLLOQUIUM LECTURE
    תאריך:
    יום שלישי, 6.6.2017, 14:30
    מקום:
    חדר 337 טאוב.
    השתייכות:
    Weizmann Institute
    מארח:
    Yuval Filmus

    One of the most common algorithmic tasks is to find a single interesting event (a needle) in an exponentially large collection (haystack) of N=3D2^n possible events, or to demonstrate that no such event is likely to exist. In particular, we are interested in the problem of finding needles which are defined as events that happen with an unusually high probability of p>>1/N in a haystack which is an almost uniform distribution on N possible events. Such a search algorithm has many applications in cryptography and cryptanalysis, and its best known time/memory tradeoff requires O(1/Mp^2) time given O(M) memory when the search algorithm can only sample values from this distribution.
    In this talk I will describe much faster needle searching algorithms when the distribution is defined by applying some deterministic function f to random inputs. Such a distribution can be modelled by a random directed graph with N vertices in which almost all the vertices have O(1) predecessors while the vertex we are looking for has an unusually large number of O(pN) predecessors. When we are given only a constant amount of memory, we propose a new search methodology which we call NestedRho. As p increases, such random graphs undergo several subtle phase transitions, and thus the log-log dependence of the time complexity T on p becomes a piecewise linear curve which bends four times. Our new algorithm is faster than the O(1/p^2) time complexity of the best previous algorithm in the full range of 1/N < p < 1, and in particular it improves it for some values of p by a significant factor of sqrt {N}. When we are given more memory, we show how to combine the NestedRho technique with the parallel collision search technique in order to further reduce its time complexity. Finally, we show how to apply our new search technique to more complicated distributions with multiple peaks when we want to find all the peaks whose probabilities are higher than p.
    The talk will be self contained, requiring no prior knowledge of cryptography. It is joint work with Itai Dinur, Orr Dunkelman, and Nathan Keller.
    Short Bio (from Wikipedia):
    Shamir received a BSc degree in mathematics from Tel Aviv University in 1973 and obtained his MSc and PhD degrees in Computer Science from the Weizmann Institute in 1975 and 1977 respectively. After a year postdoc at University of Warwick, he did research at MIT from 1977-1980 before returning to be a member of the faculty of Mathematics and Computer Science at the Weizmann Institute. Starting from 2006, he is also an invited professor at Ecole Normale Superieure in Paris.
    He is a co-inventor of the RSA algorithm (along with Ron Rivest and Len Adleman), a co-inventor of the Feige-Fiat-Shamir identification scheme (along with Uriel Feige and Amos Fiat), one of the inventors of differential cryptanalysis (along with Eli Biham), and has made many contributions to the fields of cryptography and computer science. Shamir's other numerous inventions and contributions to cryptography include the Shamir secret sharing scheme, the breaking of the Merkle-Hellman knapsack cryptosystem, visual cryptography, and the TWIRL and TWINKLE factoring devices. Shamir has also made contributions to computer science outside of cryptography, such as finding the first linear time algorithm for 2-satisfiability and showing the equivalence of the complexity classes PSPACE and IP.
    Shamir has received a number of awards, including the 2002 ACM Turing Award, the Paris Kanellakis Theory and Practice Award, the Erdoes Prize, the 1986 IEEE W.R.G. Baker Award, the UAP Scientific Prize, the Vatican's PIUS XI Gold Medal, the 2000 IEEE Koji Kobayashi Computers and Communications Award, the 2008 Israel Prize, and the 2017 Japan Prize.

  • Improving SSD-based Caches Lifetime with Write-Once Memory Codes

    דובר:
    רן קורצקי, הרצאה סמינריונית למגיסטר
    תאריך:
    יום רביעי, 7.6.2017, 11:30
    מקום:
    טאוב 601
    מנחה:
    Prof. E. Yaakobi, G. Yadgar, Prof. A. Schuster

    Solid State Disks (SSDs) have the potential to revolutionize the storage system landscape. They have gained popularity as cache devices in data centers because, they are faster in read and write operations and have lower power consumption, compared to the traditional magnetic hard disks (HDD). However, SSDs have a limited number of times it can write to a single physical location, and there is a second limitation. The SSD must perform an erase operation before it can write to the same location again. Write-once memory (WOM) codes were studied as a way to increase the number of writes on a write-once storage medium to more than once. In previous studies, the usage of WOM-codes in SSD was studied to increase its lifetime by 50%; theoretically, reusing invalid pages for additional writes, and thus reducing the number of erase operations. The additional writes are inflated when using WOM-codes and come with the cost of utilizing the overprovisioning space in SSDs to maintain constant external capacity. In cache devices, there is no such constraint on external capacity, so we could use a more significant percentage for second writes in order to extend a bit further the SSD lifetime. In this work, we propose a caching algorithm for SSD-based caches that will leverage WOM-codes to reuse invalid pages for gaining an additional number of writes in SSD. We study the use of these additional writes to improve in both cache hit ratio and SSD lifetime, without the constraint of maintaining constant external capacity.

  • CGGC Seminar: Precise Algebraic-based Swept Volumes for Arbitrary Free-form Shaped Tools towards Multi-axis CNC Machining Verification

    דובר:
    ג'נש מששר (מדעי המחשב, טכניון)
    תאריך:
    יום ראשון, 11.6.2017, 13:30
    מקום:
    חדר 337, בניין טאוב למדעי המחשב

    We will discuss a variation of the Ginzburg-Landau functional, a common tool in applications such as image segmentation (Ambrosio-Tortorelli) and phase-field methods in fluid simulation, involving a so-called "double-obstacle" barrier term (first studied by Elliott and Blowey).

    We will describe fast (GPU-optimized) variational solvers for gradient flows of these functionals (Allen-Cahn and Cahn-Hilliard equivalents), and also look into certain higher-dimensional generalisations.

  • Accelerating Multidimensional NMR Spectroscopy by Compressed Sensing of Hypercomplex FTs

    דובר:
    David L. Donoho - SPECIAL GUEST LECTURE - Note unusual hour
    תאריך:
    יום ראשון, 11.6.2017, 13:30
    מקום:
    חדר 337 טאוב.
    השתייכות:
    Stanford University
    מארח:
    Michael Elad

    Multidimensional NMR (MDNMR) experiments are an important tool in physical chemistry,but can take a long time, in some cases weeks, to conduct. At first glance, the application looks ideal for compressed sensing because the object to be recovered is sparse and the under-sampled measurements are made in the 'Fourier' domain. Actually, MDNMR is not covered by the existing compressed sensing literature. First the 'Fourier' domain is not the classical one, but involves the so-called hypercomplex Fourier transform. Second, random undersampling is not a really sensible option, because of the structure of the actual experiment. In this talk I will review this background and review recent work with Hatef Monajemi, Jeffrey Hoch and Adam Schuyler, where we find that the now traditional structures -- for example Gaussian phase transitions, which are thought to be universal -- don't accurately describe the sparsity-undersampling relation. I will give an accurate description with we think novel and interesting structure. Short Bio: ========== David Leigh Donoho is a professor of statistics at Stanford University, where he is also the Anne T. and Robert M. Bass Professor in the Humanities and Sciences. His work includes the development of effective methods for the construction of low-dimensional representations for high-dimensional data problems (multiscale geometric analysis), developments of wavelets for de-noising and compressed sensing. Donoho did his undergraduate studies at Princeton University, graduating in 1978. His undergraduate thesis advisor was John W. Tukey. Donoho obtained his Ph.D. from Harvard University in 1983, under the supervision of Peter J. Huber. He was on the faculty of the University of California, Berkeley from 1984 to 1990 before moving to Stanford. He has been the Ph.D. advisor of at least 20 doctoral students, including Jianqing Fan and Emmanuel Candes. In 1991, Donoho was named a MacArthur Fellow. He was elected a Fellow of the American Academy of Arts and Sciences in 1992. He was the winner of the COPSS Presidents' Award in 1994. In 2001, he won the John von Neumann Prize of the Society for Industrial and Applied MathematicsIn 2002, he was appointed to the Bass professorship. He was elected a SIAM Fellow and a foreign associate of the French Academie des Sciences in 2009, and in the same year received an honorary doctorate from the University of Chicago. In 2010 he won the Norbert Wiener Prize in Applied Mathematics, given jointly by SIAM and the American Mathematical Society. He is also a member of the United States National Academy of Science. In 2012 he became a fellow of the American Mathematical Society. In 2013 he was awarded the Shaw Prize for Mathematics. In 2016, he was awarded an honorary degree at the University of Waterloo. ======================================== Refreshments will be served from 13:15 Lecture starts at 13:30

  • Effective deductive verification of safety of distributed protocols in unbounded systems

    דובר:
    Mooly Sagiv - COLLOQUIUM LECTURE - RESCHEDULED
    תאריך:
    יום שלישי, 13.6.2017, 14:30
    מקום:
    חדר 337 טאוב.
    השתייכות:
    Tel-Aviv University, School of Computer Science
    מארח:
    Yuval Filmus

    Safety of a distributed protocol means that the protocol never reaches a bad state, e.g., a state where two nodes become leaders in a leader-election protocol. Proving safety is obviously undecidable since such protocols are run by an unbounded number of nodes, and their safety needs to be established for any number of nodes. I will describe a deductive approach for proving safety, based on the concept of universally quantified inductive invariants --- an adaptation of the mathematical concept of induction to the domain of programs. In the deductive approach, the programmer specifies a candidate inductive invariant and the system automatically checks if it is inductive. By restricting the invariants to be universally quantified, this approach can be effectively implemented with a SAT solver. This is a joint work with Ken McMillan (MSR), Oded Padon (TAU), Aurojit Panda (Berkeley), and Sharon Shoham(TAU) and was integrated into the IVY system http://www.cs.tau.ac.il/~odedp/ivy/ The work is inspired by Shachar Itzhaky's thesis available from http://people.csail.mit.edu/shachari/ Short Bio: ========== Mooly Sagiv is a professor in the School of Computer Science at Tel-Aviv University. He graduated from the Technion in 1991. He is a leading researcher in the area of large scale (inter-procedural) program analysis, and one of the key contributors to shape analysis. His fields of interests include programming languages, compilers, abstract interpretation, profiling, pointer analysis, shape analysis, inter-procedural dataflow analysis, program slicing, and language-based programming environments. Sagiv is a recipient of a 2013 senior ERC research grant for Verifying and Synthesizing Software Composition. Prof. Sagiv served as Member of the Advisory Board of Panaya Inc acquired by Infosys. He received best-paper awards at PLDI'11 and PLDI'12 for his work on composing concurrent data structures and a ACM SIGSOFT Retrospective Impact Paper Award (2011) for program slicing. He is an ACM fellow and a recipient of Microsoft Research Outstanding Collaborator Award 2016. ========================================== Refreshments will be served from 14:15 Lecture starts at 14:30

  • גרפיקה ממוחשבת בראיית הזמן: עבר, הווה ועתיד

    CSpecial Guest: Computer Graphics in the View of Time: Past, Present and Future

    דובר:
    אייל בר לב (אלביט, חטיבת כלי טייס)
    תאריך:
    יום רביעי, 14.6.2017, 12:30
    מקום:
    טאוב 7

    פרטים נוספים בכרזה המצורפת. כולם מוזמנים.

  • Seminar in Cryptology: Tutorial on the Construction of SHA-1 Collision Attacks

    דובר:
    מארק סטיבנס (CWI, הולנד)
    תאריך:
    יום רביעי, 14.6.2017, 12:30
    מקום:
    טאוב 201

    The cryptographic hash function SHA-1 has been known to be weak since 2004 with the first theoretical collision attack.
    Since then many techniques for SHA-1 collision attacks have been developed and refined over the years leading to our recent practical collision attack.
    In this tutorial I will present the techniques underlying our attack in detail covering things such as local collisions, disturbance vectors,
    differential trail construction, computing optimal differential characteristics, and efficient depth first tree searches on GPUs.

    This lecture will discuss the attack in details at a level intended for experts in cryptanalysis. For a more general talk see the lecture in Cryptoday on 15.06.2017 (see cryptoday.org).

  • הכנס השנתי הבינלאומי השביעי להנדסת מחשבים בטכניון בנושא צפינת איחסון ומערכות מידע

    The 7th Annual International TCE Conference on Coding for Storage and Information Systems

    תאריך:
    יום רביעי, 21.6.2017, 08:30
    מקום:
    בניין טאוב למדעי המחשב

    כנס השנתי הבינלאומי השביעי להנדסת מחשבים בטכניון בנושא צפינת איחסון ומערכות מידע יתקיים בימים רביעי-חמישי, 21-22 ביוני, 2017 בבניין טאוב למדעי המחשב, הטכניון.

    מארגני הכנס הם איתן יעקובי מהפקולטה למדעי המחשב ויובל קסוטו מהפקולטה להנדסת חשמל ובין המשתתפים:

    Alexander Barg,  University of Maryland, USA ·
    André Brinkmann, Johannes Gutenberg – Universität Mainz, Germany ·
    Lara Dolecek, UCLA, USA ·
    Ryan Gabrys, University of Illinois at Urbana-Champaign, USA ·
     Warren Gross, McGill University, Canada ·
     Danny Harnik, IBM, Israel ·
     Michael Kazhdan, Johns Hopkins University, USA ·
     Idit Keidar, Technion, Israel  HanMao Kiah, NTU, Singapore ·
     P Vijay Kumar, Indian Institute of Science, Bangalore, India ·
     Olgica Milenkovic, University of Illinois at Urbana-Champaign, USA ·
     Paul H. Siegel, UC San Diego, USA ·
    Eran Sharon, SanDisk/WD, Israel ·
     Emina Soljanin, Rutgers University, USA ·
     Ido Tal, Technion, Israel ·
     Alexander Vardy, UC San Diego, USA ·
     Zohar Yakhini, IDC, Israel ·


    הרשמה ופרטים נוספים על תוכנית הכנס ומידע על המרכז להנדסת מחשבים בטכניון TCE