IT@UU: Seminars

20 May 10:15: (TAS)@UpMarc

Magnus Själander, Post-doc, Florida State University — 2013-05-20T10:15+02:00

Magnus Själander, Post-doc, Florida State University: Power-Aware Resource Management for LTE Base Stations

1212, Mon 20 May 2013 10:15

With the proliferation of mobile phones and other mobile internet appliances, the application area of baseband processing continues to grow in importance. The number of mobile broadband subscribers has exploded in recent years with a 93% year-on-year growth in March 2009 and a 30% increase in worldwide mobile data bandwidth usage for the second quarter of 2009 alone. To meet the increasing demand of cellular and mobile broadband the number of base stations increased with 14% in 2011. Baseband stations for Long Term Evolution (LTE) communication processing tend to rely on over-provisioned resources to ensure that peak demands can be met. This over-provisioning causes ...read more »

20 May 11:15: (TAS)@UpMarc

David Whalley , E.P. Miles Professor, Florida State University — 2013-05-20T11:15+02:00

David Whalley , E.P. Miles Professor, Florida State University: Improving Processor Efficiency by Statically Pipelining Instructions

1212, Mon 20 May 2013 11:15

A new generation of applications requires reduced power consumption without sacrificing performance. Instruction pipelining is commonly used to meet application performance requirements, but some implementation aspects of pipelining are inefficient with respect to energy usage. We propose static pipelining as a new instruction set architecture to enable more efficient instruction flow through the pipeline, which is accomplished by exposing the pipeline structure to the compiler. While this approach simplifies hardware pipeline requirements, significant modifications to ...read more »

20 May 14:15: Vi2 Seminars

Åsa Cajander — 2013-05-20T14:15+02:00

Åsa Cajander: Existing but not Explicit - The User Perspective in Scrum Projects in Practice

ITC 2115, Mon 20 May 2013 14:15

Abstract:
Agile software development processes are becoming more common, but this does not mean that the user perspective in the development is catered for. It has its challenges to integrate the users? aspects in Scrum projects in practice. In order to better understand these challenges we have interviewed IT professionals using Scrum focusing on four different areas: responsibility for the user perspective, emphasis on usability and user experience through documentation, usability activities with users and the organisational and contextual settings for emphasizing the user perspective. Results show that the responsibility for the user perspective is unclear in Scrum projects, and that often the user perspective is neither discussed nor described in the projects. However, the user perspective is often present through informal feedback used to understand the context of use and inform design for example. Finally the paper presents implications for working with the user perspective in Scrum projects.

21 May 15:15: (TAS)@UpMarc

Sophia Knight, LIX Polytechnique, Paris — 2013-05-21T15:15+02:00

Sophia Knight, LIX Polytechnique, Paris: An epistemic calculus for spatially distributed systems with potential applications to social networks

ITC 4306, Tue 21 May 2013 15:15

Abstract: Information protection in distributed settings is a crucial research area. With the increasing prevalence of the internet and its involvement in every aspect of people's lives, distributed systems are becoming ubiquitous, for example, social networks and cloud computing. I will present a spatial and epistemic process calculus for reasoning about spatial information and knowledge distributed among the agents of such a system. My process calculus is based on the concurrent constraint programming paradigm, with modalities as combinators in the calculus. This makes it possible to view multi-agent epistemic logic as a programming language: one particularly adapted to security and privacy concerns.

22 May 13:15: Docentföreläsning i ämnet datavetenskap med inriktning mot datorkommunikation

Christian Rohner — 2013-05-22T13:15+02:00

Christian Rohner: Sökning i distribuerade mobila nätverk

ITC 2446, Wed 22 May 2013 13:15

Sökfunktioner är idag det vanligaste sättet att hitta information på nätet och på den egna datorn. En viktig egenskap hos sökningsalgoritmer är att hitta den mest relevanta informationen i mängden av alla möjliga träffar.

Opportunistiska nätverk är ett paradigm i trådlös mobil kommunikation där noder byter ut information när de är nära varandra. Nätverket är därför dynamiskt och sannolikt segmenterat. Sökning och spridning av information inom nätverket kan därmed inte använda sig av en global syn på nätverket utan ska förlita sig på nodernas lokala syn för att ta beslut vilken information som ska bytas ut när två noder möts. Denna föreläsning diskuterar användning av sökning som central princip för att effektivt hitta relevant information inom ett opportunistiskt nätverk.

Docenturnämndens representant: Professor Ingela Nyström

Föreläsningen hålls på svenska.

23 May 10:30: (TAS)@UpMarc

Frédéric Haziza — 2013-05-23T10:30+02:00

Frédéric Haziza : An Integrated Specification and Verification Technique for Highly Concurrent Data Structures

1145, Thu 23 May 2013 10:30

We present a technique for automatically verifying safety properties of concurrent programs, in particular programs which rely on subtle dependencies of local states of different threads, such as lock-free implementations of stacks and queues in an environment without garbage collection. Our technique addresses the joint challenges of infinite-state specifications, an unbounded number of threads, and an unbounded heap managed by explicit memory allocation. Our technique builds on the automata-theoretic approach to model checking, in which a ...read more »

This work received the EASST Best Paper Award at the ETAPS 2013 joint conferences in Rome, Italy.

23 May 13:00: Posterutställning av IT åk 3

LäsIT: Seminars — 2013-05-23T13:00+02:00

Studentprojekten för Självständigt arbete och Uppsatsmetodik på IT-programmets årskurs 3 har posterutställning i korridoren på plan 2 i hus 2. Varmt välkomna!

23 May 15:15: Seminar at Systems and Control

2013-05-23T15:15+02:00

Prof. Amit Mitra, Department of Mathematics & Statistics, Indian Institute of Technology Kanpur, India: on Estematin the Parameters of a Non-Linear Chirp Signal Model

ITC 2344, Thu 23 May 2013 15:15

Language: English

Abstract
Estimation of the parameters of chirp signal model is a fundamental problem in signal processing and has been of interest for a long time. Chirp signals embedded in additive noise occur in a variety of signal processing applications, e.g. in SAR, inverse SAR imaging, sonar and communications. Given a set of observed signals, the problem is to estimate the unknown frequencies and the frequency rates associated with such a chirp model. In this talk, we present some recent results in this area. Theoretical asymptotic properties of important estimators of the parameters of a real valued non-linear chirp signal model will be discussed.
We first consider the non-linear least squares estimators (NLSE) of the parameters of a chirp model in the presence of a stationary additive noise. Using a number theoretic result, we present a simplified form of the asymptotic variance covariance matrix of the NLSE. We also present a sequential estimation procedure for obtaining the NLSE of a superimposed chirp model and establish, asymptotically, that the proposed estimators are strongly consistent.
We further study the asymptotic theoretical properties of robust least absolute deviation (LAD) estimators of the parameters of a chirp model in the presence of additive white noise. We establish that the LAD estimators are strongly consistent, find the convergence rates and present the form of the asymptotic joint distribution of the resultant estimators.
A computationally efficient algorithm for estimating the frequencies and the frequency rates of a chirp signal model in the presence of stationary noise will also be presented. We show that the proposed iterative algorithm yields efficient estimators in a fixed number of iterations. Strong consistency results and asymptotic equivalence of the proposed estimators and the NLSE of the corresponding parameters will be presented.

All are welcome!

31 May 14:00: Licentiate seminar at TDB

Marcus Holm — 2013-05-31T14:00+02:00

Marcus Holm: Scientific Computing on Hybrid Architectures

ITC 2446, Fri 31 May 2013 14:00

Opponent: Dr. Xing Cai, Senior Research Scientist at Simula Research Laboratory and Professor at the University of Oslo

The discussion will be held in English.

Abstract: Modern computer architectures, with multicore CPUs and GPUs or other accelerators, make stronger demands than ever on writers of scientific code. Normally, the most efficient program has to be written - using a substantial effort - by expert programmers for a certain application on a particular computer. This thesis deals with several algorithmic and technical approaches towards effectively satisfying the demand for high performance parallel scientific applications on hybrid computer architectures without incurring such a high cost in expert programmer time. Efficient programming is accomplished by writing performance-portable code where performance-critical functionality is provided either by an optimized library or by adaptively selecting which computational tasks that are executed on the CPU and the accelerator.

31 May 14:15: Seminar at Systems and Control

2013-05-31T14:15+02:00

Ass. Prof. Sharmishtha Mitra, Department of Mathematics & Statistics, Indian Institute of Technology Kanpur, India: Analysis of Life Testing Models under different censoring and stress acceleration schemes

ITC 2344, Fri 31 May 2013 14:15

Language: English

Abstract
Traditional life data analysis analyzes time-to-failure data (of a product, system or component) obtained under normal operating conditions to quantify the life characteristics of the objects. Accelerated life test (ALT) is a popular experimental strategy to obtain information on life distributions of highly reliable products. The main idea is to submit materials to higher than usual environmental conditions, or stress, to ensure early failure. Data obtained from such an experiment need to be extrapolated to estimate lifetime distribution under normal conditions.
A Step-Stress life test is a particular type of ALT. We observe the failure times of the products at a particular stress level, and then change the stress to a different level. Failure times in the new stress level are observed, and the stress level is changed again and so on. There are several stress loading schemes - constant stress, step-stress, ramp-stress, progressive stress, etc. Introduction of stresses ensures a reasonable number of failures and reduces the experimental time. The stress structure and the lifetime distribution have to be combined to get the comprehensive ALT model.
The analysis relies on life and stress data or time-to-failure data at a specific stress level. Data are either complete or censored. In this talk we discuss various aspects of the exact inference for the two-parameter Exponential distribution (a standard life-time distribution) under Type-II Hybrid Censoring (a popular censoring method) and Bayesian analysis of different Hybrid and Progressive Life Tests. This would be followed by exact and approximate inference procedures for a Simple Step-Stress model under Exponential distribution with location and scale parameters. We shall further consider the order restricted Bayesian inference for the Exponential Simple Step-Stress Model. Finally, Bayesian analysis of Simple Step-stress Model under Weibull lifetimes (another standard lifetime distribution) would be discussed in brief.

All are welcome!

4 June 14:00: Licentiatseminarium

Daniel Elfverson — 2013-06-04T14:00+02:00

Daniel Elfverson: On Discontinuous Galerkin Multiscale Methods

ITC 2446, Tue 4 Jun 2013 14:00

Abstract

5 June 10:15: Disputation

Stefan Hellander — 2013-06-05T10:15+02:00

Stefan Hellander: Stochastic simulation of reaction-diffusion processes

ITC 2446, Wed 5 Jun 2013 10:15

18 June 10:30: (TAS)@UpMarc

David Broman — 2013-06-18T10:30+02:00

David Broman : Modelyze: Embedding DSLs for Modeling and Analyzing Cyber-Physical Systems

1112, Tue 18 Jun 2013 10:30

Cyber-physical systems combine computations, networks, and physical processes. Modeling and analysis of such systems are vital engineering techniques to mange complexity and enable rapid prototyping. In particular, complex cyber-physical systems are heterogenous, requiring various model of computations. A key challenge is to provide both expressive modeling capabilities and mechanisms for analyzing these heterogenous systems. This talk explores a solution to this challenge based on domain-specific embedded languages. We introduce a host language, named Modelyze, in which various domain-specific modeling languages may be embedded. The key features of ...read more »