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

  • Market Driven Queuing

    דובר:
    בוריס פיסמניי, הרצאה סמינריונית למגיסטר
    תאריך:
    יום שני, 5.12.2016, 15:30
    מקום:
    טאוב 301
    מנחה:
    Prof. Assaf Schuster and Dr. Orna Agmon Ben-Yehuda

    Network providers must dynamically allocate scarce physical resources among their clients to maximize benefit. Network pricing is one way for providers to maximize client benefit by allowing them to share available bandwidth according to their willingness to pay for it. The resulting allocation grants additional bandwidth to those who need it the most, while decreasing the bandwidth of those who need it the least. Existing queueing algorithms use the results of pricing schemes as weights for sharing bandwidth, which can change only in response to a change in client willingness to pay. However, network congestion, jitter and failures affecting a flow create excess bandwidth that could be used by another flow. Queueing algorithms that can share the excess bandwidth are called work-conserving. Network pricing schemes traditionally ignore work conservation, by assuming that all clients are constantly backlogged. In this paper, we design and evaluate the Market Driven Queueing (MDQ) algorithm. By combining a queueing algorithm with a bandwidth pricing mechanism, MDQ provides the benefits of both. As a work-conserving algorithm, MDQ maximizes client benefit while improving utilization. Moreover, it requires only O(log(n)) processing time per packet, where n is the number of active flows. We analyse the properties of MDQ and evaluate it using simulation. Our simulation results show that MDQ improves clients’ aggregated benefit by up to 4x compared to state-of-the-art combinations of pricing and queueing algorithms. MDQ is also applicable to other scheduling problems such as distributed queues or I/O queue scheduling.

  • Pixel Club: Signal Modeling: From Convolutional Sparse Coding to Convolutional Neural Networks

    דובר:
    ורדן פפיאן (מדעי המחשב, טכניון)
    תאריך:
    יום שלישי, 6.12.2016, 11:30
    מקום:
    חדר 337, בניין טאוב למדעי המחשב

    Within the wide field of sparse approximation, convolutional sparse coding (CSC) has gained increasing attention in recent years. This model assumes a structured-dictionary built as a union of banded Circulant matrices. Most attention has been devoted to the practical side of CSC, proposing efficient algorithms for the pursuit problem, and identifying applications that benefit from this model. Interestingly, a systematic theoretical understanding of CSC seems to have been left aside, with the assumption that the existing classical results are sufficient.

    In this talk we start by presenting a novel analysis of the CSC model and its associated pursuit. Our study is based on the observation that while being global, this model can be characterized and analyzed locally. We show that uniqueness of the representation, its stability with respect to noise, and successful greedy or convex recovery are all guaranteed assuming that the underlying representation is locally sparse. These new results are much stronger and informative, compared to those obtained by deploying the classical sparse theory.

    Armed with these new insights, we proceed by proposing a multi-layer extension of this model, ML-CSC, in which signals are assumed to emerge from a cascade of CSC layers. This, in turn, is shown to be tightly connected to Convolutional Neural Networks (CNN), so much so that the forward-pass of the CNN is in fact the Thresholding pursuit serving the ML-CSC model. This connection brings a fresh view to CNN, as we are able to attribute to this architecture theoretical claims such as uniqueness of the representations throughout the network, and their stable estimation, all guaranteed under simple local sparsity conditions. Lastly, identifying the weaknesses in the above scheme, we propose an alternative to the forward-pass algorithm, which is both tightly connected to deconvolutional and recurrent neural networks, and has better theoretical guarantees.

    ​​Short bio:
    Vardan Papyan received the B.Sc. degree from the Department of Computer Science, Technion– Israel Institute of Technology, in 2013, where he is currently pursuing his Ph.D. degree. His research interests include signal and image processing, deep learning and its relation to sparsity-based modeling of signals.

  • ceClub: From Theory to Practice: The Actual Outcome of Two 'Somewhat Disjoint' Network Evaluation Studies

    דובר:
    יוסי ילוז (הנדסת חשמל,טכניון ואינטל)
    תאריך:
    יום רביעי, 7.12.2016, 11:30
    מקום:
    חדר 861, בניין מאייר, הפקולטה להנדסת חשמל

    Network Function Virtualization (NFV) is a novel paradigm that enables flexible and scalable implementation of network services on cloud infrastructure, while Network Survivability is an traditional well-studied subject for maintaining network service continuity in the presence of failures. This talk will address these two important subjects through the results of two recent papers, namely "Optimal Link-Disjoint Node-“Somewhat Disjoint” Paths"[1] and "The Actual Cost of Software Switching for NFV Chaining"[2].

    In [1], we investigate a crucial research problem in this context is the identification of suitable pairs of disjoint paths. Here, “disjointness” can be considered in terms of either nodes or links. Accordingly, several studies have focused on finding pairs of either link or node disjoint paths with a minimum sum of link weights. In this study, we investigate the gap between the optimal node-disjoint and link disjoint solutions. Specifically, we formalize several optimization problems that aim at finding minimum-weight link-disjoint paths while restricting the number of its common nodes. We establish that some of these variants are computationally intractable, while for other variants we establish polynomial-time algorithmic solutions. Finally, through extensive simulations, we show that, by allowing link-disjoint paths share a few common nodes, a major improvement is obtained in terms of the quality (i.e., total weight) of the solution.

    In [2], we conduct an extensive and in-depth evaluation that examines the impact of service chaining deployments on Open vSwitch – the de facto standard software switch for cloud environments. We provide insights on network performance metrics such as latency, throughput, CPU utilization and packet processing, while considering different placement strategies of a service chain. We then use these insights to provide an abstract generalized cost function that accurately captures the CPU switching cost of deployed service chains. This cost is an essential building block for any practical optimized placement management and orchestration strategy for NFV service chaining.

    [1] Jose Yallouz, Ori Rottenstreich, Péter Babarczi, and Ariel Orda, "Optimal Link-Disjoint Node-'Somehow Disjoint' Paths", IEEE ICNP '16, Singapore, November 2016.
    [2] Marcelo Caggiani Luizelli, Danny Raz, Yaniv Saar and Jose Yallouz, "The Actual Cost of Software Switching for NFV Chaining", accepted to IEEE IM '17.

    Bio:
    Jose Yallouz received a Ph.D. and a B.Sc. from the Electrical Engineering department of the Technion at 2016 and 2008, respectively. He recently joined the Core Architecture team at Intel Corporation. He was a recipient of the Israel Ministry of Science Fellowship in Cyber and advance Computing award. Among his past activities were the organization of the CeClub seminar and the Netmeeting forum. He is mainly interested in computer networks, computer architecture and compilers.

  • Theory Seminar: Online Matching: Haste Makes Waste!

    דובר:
    יובל עמק (תעשייה וניהול, טכניון)
    תאריך:
    יום רביעי, 7.12.2016, 12:30
    מקום:
    טאוב 201

    We address a new online problem, referred to as min-cost perfect matching with delays (MPMD), where requests arrive in a continuous time online fashion at the points of a finite metric space $mathcal{M}$ and should be served by matching them to each other.

    The algorithm that knows $mathcal{M}$ in advance is allowed to delay its matching commitments, but this does not come for free: the total cost of the algorithm is the sum of metric distances between matched requests plus the sum of times each request waited since it arrived until it was matched.

    In this talk, we discuss the MPMD problem, its applications, and some recent advances in studying its competitiveness.

    The talk will be self contained.

  • Finding Security Vulnerabilities in Network Protocols Using Methods of Formal Verification

    דובר:
    עדי סוסנוביץ, הרצאה סמינריונית לדוקטורט
    תאריך:
    יום רביעי, 7.12.2016, 15:30
    מקום:
    טאוב 601
    מנחה:
    Prof. Orna Grumberg

    The Internet infrastructure relies almost entirely on network protocols that are based on open standards. However, the majority of network devices on the Internet, e.g. routers and switches, are proprietary and closed source. Hence, there is no straightforward way to analyze them. Specifically, one cannot easily and systematically identify deviations of a network device's protocol implementation from the protocol's standard. Such deviations may degrade the security or resiliency of the network. In this talk I will present our work on a formal analysis of black boxes in the network. We develop a formal black-box method to unearth non-standard protocol deviations in closed-source network devices. The method relies only on the ability to test the targeted protocol implementation and observe its output. We use a model-based testing approach, which relies on a formal model of the protocol in question. We develop optimizations that are tailored to the analysis of network protocols, to allow reducing the number of generated tests without loss of functionality cover of the model. We evaluate our method against the OSPF protocol. We search for deviations in the OSPF implementation of Cisco - the largest networking vendor in the world. Our evaluation identified numerous significant deviations. Some of them can be abused to compromise the security of a network. The deviations were acknowledged by Cisco to exist in the versions we tested. I will briefly describe other topics in my thesis.

  • CGGC Seminar: OpenMP - In Practice

    דובר:
    בעז שטרנפלד (מדעי המחשב, טכניון)
    תאריך:
    יום ראשון, 11.12.2016, 13:30
    מקום:
    חדר 337, בניין טאוב למדעי המחשב

    OpenMP is an API for writing multithreaded, shared memory parallelism, it consists of a set of compiler directives none intrusive to the original serial code. In addition I shall present parfor concept in MATLAB which is useful where you need many loop iterations of a simple calculation.

  • Pixel Club: Arranging & Improving Photos

    דובר:
    אוהד פריד (אונ' פרינסטון)
    תאריך:
    יום ראשון, 11.12.2016, 14:30
    מקום:
    חדר 1061, בניין מאייר, הפקולטה להנדסת חשמל

    There are *many* photos in the world. An average user might have thousands of photos in their personal photo collection. We have reached a point where photo acquisition is trivial, and the next challenge lies in arranging and easily editing such large photo collections. I will start the talk by briefly surveying a few of our works that aim to arrange large collections, and to provide fast (yet sophisticated) image manipulation techniques. Next, I will describe a new type of photo elements: “distractors” and explain how those are related yet different from saliency, and how we can automatically detect them. Lastly, I will present our latest work that can fix perspective distortions in portrait photos.​​

    Bio:
    Ohad Fried is a PhD student in the Computer Science Department at Princeton University. His work lies in the intersection of computer graphics, computer vision, and HCI. Previously, he received an M.Sc. in Computer Science and a B.Sc. in Computational Biology from The Hebrew University. Ohad’s research focuses on tools, algorithms, and new paradigms for photo editing. He published research papers in premier venues, including SIGGRAPH, CVPR, Eurographics, and NIME. Ohad is the recipient of several awards, including a Siebel Scholarship, a Google PhD Fellowship and a Princeton Gordon Y.S. Wu Fellowship in Engineering. If you own a cable modem, there’s a non-negligible chance that Ohad’s code runs within it, so feel free to blame him for your slow internet connection. www.ohadf.com

  • Linear and Generalized Linear Mixed Models for Genetic Case Control Studies

    דובר:
    עומר ויסברוד, הרצאה סמינריונית לדוקטורט
    תאריך:
    יום רביעי, 14.12.2016, 13:00
    מקום:
    טאוב 601
    מנחה:
    Prof. Dan Geiger and Prof. Saharon Rosset

    In recent years, genetic studies have revolutionized our understanding of common diseases like diabetes and cancer. However, the analysis of genetic studies of disease poses substantial statistical and computational challenges, owing to the data collection scheme and to the extremely large data dimensionality. We propose a unified modeling framework that addresses these challenges in order to solve the three main problems associated with genetic disease studies: Searching for disease causing mutations, predicting risk of being affected with a disease, and inferring the overall genetic architecture of diseases. Our proposed solutions are based on generalized linear mixed models, and employ techniques from diverse fields, such as multiple kernel learning from machine learning and the method of moments from statistics. The proposed methodologies lead to state of the art results in the three main problems of genetic studies of disease, and have been published in top scientific journals. The talk is aimed towards a general audience, and does not require statistical or biological background.

  • Cloud resource provisioning for social notifications at mass scale

    דובר:
    Roman Vitenberg - COLLOQUIUM LECTURE
    תאריך:
    יום חמישי, 15.12.2016, 14:30
    מקום:
    חדר 337 טאוב.
    קישור:
    http://www.cs.technion.ac.il/~colloq/20161215_14_30_Vitenberg.html
  • יום עיון לרגל פרישתו של פרופ' יוהן מקובסקי

    A Workshop in Honor of Prof. Johann Makowsky’s Retirement

    תאריך:
    יום ראשון, 25.12.2016, 13:30
    מקום:
    חדר 337, בניין טאוב למדעי המחשב

    הפקולטה למדעי המחשב תקיים יום עיון לרגל פרישתו של פרופ' יוהן מקובסקי בנושא: Logic in Computer Science and Combinatorics

    בתוכנית דברי ברכה מפי דיקן הפקולטה, פרופ' עירד יבנה, והרצאות מפי:
    משה ורדי
    אלדר פישר
    תומר קוטק
    נדיה לבאי
    אלנה רווה
    יוהן מקובסקי

    פרטים נוספים ותוכנית מלאה

    האירוע יתקיים ביום ראשון, 25 בדצמבר 2016 בין השעות 13:00-17:00, בחדר 337, בניין טאוב למדעי המחשב בטכניון

    כולם מוזמנים!

  • Requirements for Tools for Hairy Requirements or Software Engineering Tasks

    דובר:
    Daniel M. Berry - COLLOQUIUM LECTURE
    תאריך:
    יום שלישי, 27.12.2016, 14:30
    מקום:
    חדר 337-8 טאוב.
    קישור:
    http://www.cs.technion.ac.il/~colloq/20161227_14_30_Berry.html
  • On Artificial Olfaction, and How to Test For It

    דובר:
    David Harel - COLLOQUIUM LECTURE
    תאריך:
    יום שלישי, 3.1.2017, 14:30
    מקום:
    חדר 337-8 טאוב.
    קישור:
    http://www.cs.technion.ac.il/~colloq/20170103_14_30_Harel.html
  • Antibiotic resistance: machine learning to the rescue

    דובר:
    Roy Kishony - COLLOQUIUM LECTURE
    תאריך:
    יום שלישי, 17.1.2017, 14:30
    מקום:
    חדר 337-8 טאוב.
    קישור:
    http://www.cs.technion.ac.il/~colloq/20170117_14_30_Kishony.html