Seminar

Important

Starting November 2018, I am on extended academic leave. This website, as well as contact information, etc. are no longer up-to-date. Please check https://nonsns.github.io for more information

Information!

Unfortunately the DSI migration to an LXC based solution (with no root access!) completely broke the seminar system. My whole poor-man system was built over BibTex/Web and Cron. Unfortunately the LXC PHP version conflicts with PmWiki and my previous system, so I migrated to Jekyll. Unfortuantely Jekyll scholar is very fragile and picky, so that typos, UTF-8 characters etc. risk of breaking my full webpage! Unfortunately the LXC does not support anything (cron, svn, git) and does not allow any outbound connections. As such, as a bonus, the migration also broke the automated email annouce :( Despite the amount of effort I put into it so far, I haven't been able to find a fix. Having run this service for 10 years now, I am happy to let it run by any volounteer from now on -- please raise your hand!

Upcoming seminars 8

2018/03/01 Time TBD (check with petr.kuznetsov@telecom-paristech.fr @ Room TBD (check with petr.kuznetsov@telecom-paristech.fr
Gramoli, Vincent (University of Sydney)
The Red Belly Blockchain: Consistency and Scalability
2018/02/07 14h @ LINCS, Seminar Room
de Veciana, Gustavo (The University of Texas at Austin)
Network Slicing Games: Enabling Statistical Multiplexing of Multi-tenant Spatial Loads
2018/02/14 14h @ LINCS, Seminar Room
Charpentier, Bertrand (Telecom ParisTech)
A Sliding-Resolution Algorithm for Hierarchical Graph Clustering
2018/02/02 11h @ Telecom ParisTech, Amphi Saphir
Davis, Jim (University of Richmond)
Apple vs. Samsung: a Mathematical Battle
2018/01/31 14h @ LINCS, Seminar Room
Qiu, Han (Telecom ParisTech)
An Efficient Data Protection Architecture Based on Fragmentation and Encryption
2018/01/24 14h @ LINCS, Seminar Room
Comte, Celine (Nokia Bell Labs France and Telecom ParisTech)
Performance of Balanced Fairness in Resource Pools: A Recursive Approach
2018/01/17 14h @ LINCS, Seminar Room
Lee, Uichin (Kaist, Korea)
Mobile and Wearable Sensing for Positive Computing
2018/01/03 14h @ LINCS, Seminar Room
Paramo, Diego Pacheco (Universidad Sergio Arboleda, Colombie)
Reinforcement Learning for Efficient Access Control with M2M/H2H traffic in LTE-A networks

Details

2018/03/01 Time TBD (check with petr.kuznetsov@telecom-paristech.fr @ Room TBD (check with petr.kuznetsov@telecom-paristech.fr
Gramoli, Vincent (University of Sydney)
Title The Red Belly Blockchain: Consistency and Scalability
Abstract To cope with blockchain inconsistencies, like double-spending, developers started building upon Byzantine fault-tolerant (BFT) consensus. At first it seems reasonable because consensus can be effective at totally ordering transactions into a chain. Unfortunately, these two problems are different. In short, the blockchain problem aims at totally ordering blocks of transactions issued by a large set of potentially misbehaving internet machines, whereas the consensus problem aims at deciding upon one of the values proposed by typically fewer but non-misbehaving machines. In this talk, I will describe the blockchain consensus problem, a variant of the classic consensus definition, that was recently defined for blockchains. I will present the Red Belly Blockchain, a blockchain that does not use BFT consensus as a black box but rather solves the blockchain consensus problem and illustrate empirically the benefits it offers.
2018/02/07 14h @ LINCS, Seminar Room
de Veciana, Gustavo (The University of Texas at Austin)
Title Network Slicing Games: Enabling Statistical Multiplexing of Multi-tenant Spatial Loads
Abstract Next generation wireless architectures are expected to enable slices of shared wireless infrastructure which are customized to specific mobile operators/services. Given infrastructure costs and the stochastic nature of mobile services’ spatial loads, it is highly desirable to achieve efficient statistical multiplexing amongst network slices. This talk will introduce a simple dynamic resource sharing policy which allocates a ‘share’ of a pool of (distributed) resources to each slice– Share Constrained Proportionally Fair (SCPF). We give a characterization of the achievable performance gains over static slicing, showing higher gains when a slice’s spatial load is more ’imbalanced’ than, and/or ’orthogonal’ to, the aggregate network load. Under SCPF, traditional network dimensioning translates to a coupled share dimensioning problem, addressing the existence of a feasible share allocation given slices’ expected loads and performance requirements. We provide a solution to robust share dimensioning for SCPF-based network slicing. Slices may wish to unilaterally manage their users’ performance via admission control which maximizes their carried loads subject to performance requirements. We show this can be modeled as a “traffic shaping" game with an achievable Nash equilibrium. Under high loads the equilibrium is explicitly characterized, as are the gains in the carried load under SCPF vs. static slicing. Detailed simulations of a wireless infrastructure supporting multiple slices with heterogeneous mobile loads show the fidelity of our models and range of validity of our high load equilibrium analysis. Joint work with Pablo Caballero, Jiaxiao Zheng, Albert Banchs, Xavier Costa, Seung Jun Baek
2018/02/14 14h @ LINCS, Seminar Room
Charpentier, Bertrand (Telecom ParisTech)
Title A Sliding-Resolution Algorithm for Hierarchical Graph Clustering
Abstract We propose a novel algorithm for the hierarchical clustering of graphs. The algorithm is a simple but key modification of the Louvain algorithm based on some sliding-resolution scheme. In particular, the most relevant clusterings, corresponding to different resolutions, are identified. The algorithm is parameter-free and has a complexity of O(m log n) where n is the number of nodes and m the number of edges. Numerical experiments on both synthetic and real datasets show the accuracy and scalability of the algorithm. Joint work with Thomas Bonald (Telecom ParisTech), Alexandre Hollocou (Inria), Alexis Galland (Inria)
2018/02/02 11h @ Telecom ParisTech, Amphi Saphir
Davis, Jim (University of Richmond)
Title Apple vs. Samsung: a Mathematical Battle
Abstract Apple and Samsung have been fighting patent battles around the world. Come learn about the mathematics at the heart of one of these battles, the error correcting codes used in 3G communication. We will give a gentle introduction to coding theory, explain why this caused a legal battle, and we will conclude by describing why President Obama ultimately vetoed the ruling by the court (the first time a president had used that veto power in nearly 30 years!).
2018/01/31 14h @ LINCS, Seminar Room
Qiu, Han (Telecom ParisTech)
Title An Efficient Data Protection Architecture Based on Fragmentation and Encryption
Abstract In this presentation, a completely revisited secure data storage and transmission scheme is presented. This new scheme is based on an agnostic selective encryption methods combined with fragmentation and dispersion. Discrete Wavelet Transform (DWT) is used as the preprocessing method to determine the selection process before encryption and to guarantee the agnostic property of the protection. Also, General Purpose Graphic Processing Unit (GPGPU) is deployed to allow performance to be very efficient compared with full encryption algorithms. During the protection process, the data is fragmented to be private fragments with small storage space and public fragments with large storage space. Then the dispersion step will distribute the fragments to different storage environments aiming at utilizing the convenient and inexpensive cloud storage space while provide security for the data. This design, with practical experimentations on different hardware configurations, provides strong level of protection and good performance at the same time plus flexible storage dispersion schemes.
2018/01/24 14h @ LINCS, Seminar Room
Comte, Celine (Nokia Bell Labs France and Telecom ParisTech)
Title Performance of Balanced Fairness in Resource Pools: A Recursive Approach
Abstract Understanding the performance of a pool of servers is crucial for proper dimensioning. One of the main challenges is to take into account the complex interactions between servers that are pooled to process jobs. In particular, a job can generally not be processed by any server of the cluster due to various constraints like data locality. In this paper, we represent these constraints by some assignment graph between jobs and servers. We present a recursive approach to computing performance metrics like mean response times when the server capacities are shared according to balanced fairness. While the computational cost of these formulas can be exponential in the number of servers in the worst case, we illustrate their practical interest by introducing broad classes of pool structures that can be exactly analyzed in polynomial time. This extends considerably the class of models for which explicit performance metrics are accessible. This is a joint work with Thomas Bonald and Fabien Mathieu.
2018/01/17 14h @ LINCS, Seminar Room
Lee, Uichin (Kaist, Korea)
Title Mobile and Wearable Sensing for Positive Computing
Abstract Recent advances in mobile and wearable technologies bring new opportunities for positive computing that aims to use computing technologies to support human well-being and potential. In particular, mobile and wearable technologies help us to better understand and deal with various threats to the well-being of people, ranging from technology overuse such as productivity loss to mental problems such as stress and depression. In this talk, I’ll present some of my recent study results about leveraging mobile and wearable sensing for positive computing: (1) mobile usage data analysis to understand and identify problematic smartphone usage behaviors; (2) wearable sensor data analysis to quantify the patterns of smartwatch wearing behaviors; (3) motion sensor data analysis to infer dangerous trails for walking with crowdsensing techniques.
2018/01/03 14h @ LINCS, Seminar Room
Paramo, Diego Pacheco (Universidad Sergio Arboleda, Colombie)
Title Reinforcement Learning for Efficient Access Control with M2M/H2H traffic in LTE-A networks
Abstract Although many advantages are expected from the provision of services for M2M communications in cellular networks such as extended coverage, security, robust management and lower deployment costs, coexistence with a large number of M2M devices is still an important challenge, in part due to the difficulty in allowing simultaneous access. Although the random access procedure in LTE-A is adequate for H2H communications, it is necessary to optimize this mechanism when M2M communications are considered. One of the proposed methods in 3GPP is Access Class Barring (ACB), which is able to reduce the number of simultaneous users contending for access. However, it is still not clear how to adapt its parameters in dynamic or bursty scenarios, such as those that appear when M2M communications are introduced.We propose a dynamic mechanism for ACB based on reinforcement learning, which aims to reduce the impact that M2M communications have over H2H communications, while at the same time ensuring that the KPIs for all users are in acceptable levels.