Event-Triggered Estimation of Linear Systems: An Iterative Algorithm and Optimality Properties

This report investigates the optimal design of event-triggered estimation for first-order linear stochastic systems. The problem is posed as a two-player team problem with a partially nested information pattern. The two players are given by an estimator and an event-trigger. The event-trigger has full state information and decides, whether the estimator shall obtain the current state information by transmitting it through a resource constrained channel. The objective is to find an optimal trade-off between the mean squared estimation error and the expected transmission rate. The proposed iterative algorithm alternates between optimizing one player while fixing the other player. It is shown that the solution of the algorithm converges to a linear predictor and a symmetric threshold policy, if the densities of the initial state and the noise variables are even and radially decreasing functions. The effectiveness of the approach is illustrated on a numerical example. In case of a multimodal distribution of the noise variables a significant performance improvement can be achieved compared to a separate design that assumes a linear prediction and a symmetric threshold policy

Web Monitoring Inteface for Call Center based on Asterisk PBX

Cílem této bakalářské je práce vytvoření webového rozhraní pro správu menších call center. Hlavní součástí práce je seznámení se s technologií VoIP a jejími protokoly, systémem Asterisk, který implementuje telefonní ústřednu (PBX) na běžném počítači, propojení s databázovým systémem MySQL a následná implementace webového serveru, který nám poskytuje webové rozhraní na základě logů CEL poskytnutých systémem Asteriskem. Výstupem práce je webová aplikace pro monitorování dostupných linek, probíhajících hovorů, front a dostupných agentů.Subject of this bachelor thesis is designing web application for monitoring and managing small call centers. Main points of the thesis are introduction to VoIP technology and it's protocols, Asterisk system, which implements private branch exchange (PBX) on regular computer, connection with MySQL database system and implementation of web server, which provides us with web interface based on CEL logs provided by Asterisk PBX. Result of the thesis is web application for monitoring available lines, ongoing calls, queues and available agents.440 - Katedra telekomunikační technikydobř

Vi och Dem : en studie av Sydsvenskans etniska framställning

I det mångkulturella samhälle Sverige idag är, har dagstidningar en viktig roll i att spegla detta samhälle på ett korrekt sätt. Vi har intresserat oss för hur personer med annan etnicitet presenteras och hur ämnen som immigration och integration framställs i Sydsvenskan. Vi vill undersöka hur representationen ser ut och om den kan tänkas vara en bidragande orsak till vardagens problem, såsom diskriminering och rasism. Vi valde en kvalitativ metod, nämligen text- och diskursanalys på ett 20-tal upplagor från april 2013. Dessutom analyserade vi samma period 1979 för att få ett tidsperspektiv till den moderna upplagan. Vi studerade inrikesnyheter och koncentrerade oss särskilt på de artiklar som innehöll personer med utländsk bakgrund, samt rapporter och diskussioner om invandring och integration. Vi använde oss av ett flertal teorier som forskats fram om medias rapportering kring etnicitet. Det var övervägande en representativ behandling i de texter vi analyserade, men vi kunde urskilja en del problematiska framställningar av framförallt flyktingar och asylpolitik. Något som stämde väl överens med vårt teoretiska material. Vi fastslog även att tidningen genom åren har utvecklats, främst i sina rapporter om invandrare där de 2013 deltar på ett mer representativt sätt än 1979. Medie- och kommunikationsvetenskap, vid instutionen för kommunikation och medier, Lunds universitet

Assume/Guarantee Contracts for Dynamical Systems:Theory and Computational Tools

Modern engineering systems include many components of different types and functions. Verifying that these systems satisfy given specifications can be an arduous task, as most formal verification methods are limited to systems of moderate size. Recently, contract theory has been proposed as a modular framework for defining specifications. In this paper, we present a contract theory for discrete-time dynamical control systems relying on assume/guarantee contracts, which prescribe assumptions on the input of the system and guarantees on the output. We then focus on contracts defined by linear constraints, and develop efficient computational tools for verification of satisfaction and refinement based on linear programming. We exemplify these tools in a simulation example, proving safety for a two-vehicle autonomous driving setting.Comment: 7 pages, 5 figure

A Multi-Vehicle Control Framework With Application to Automated Valet Parking

We introduce a distributed control method for coordinating multiple vehicles in the framework of an automated valet parking (AVP) system. The control functionality is distributed between an infrastructure server, called parking area management (PAM) system, and local autonomous vehicle control units. Via a vehicle-to-infrastructure (V2I) communication interface, model predictive control (MPC) decisions of the vehicles are shared with the coordination unit in the PAM. This unit in turn computes a coupling feedback which is shared with the vehicles. The control system is integrated in an automated test-system to cope with the high test requirements and short development cycles of highly automated systems. Evaluations conducted with the test-system show the functionality of the proposed distributed control method for multi-vehicle coordination. Results indicate safe coordination, and an efficiency increase compared to an uncoordinated method in an AVP simulation environment

OpenSBT: A Modular Framework for Search-based Testing of Automated Driving Systems

Search-based software testing (SBT) is an effective and efficient approach for testing automated driving systems (ADS). However, testing pipelines for ADS testing are particularly challenging as they involve integrating complex driving simulation platforms and establishing communication protocols and APIs with the desired search algorithm. This complexity prevents a wide adoption of SBT and thorough empirical comparative experiments with different simulators and search approaches. We present OpenSBT, an open-source, modular and extensible framework to facilitate the SBT of ADS. With OpenSBT, it is possible to integrate simulators with an embedded system under test, search algorithms and fitness functions for testing. We describe the architecture and show the usage of our framework by applying different search algorithms for testing Automated Emergency Braking Systems in CARLA as well in the high-fidelity Prescan simulator in collaboration with our industrial partner DENSO. OpenSBT is available at https://git.fortiss.org/opensbt

Formal Specification for Learning-Enabled Autonomous Systems

The formal specification provides a uniquely readable description of various aspects of a system, including its temporal behavior. This facilitates testing and sometimes automatic verification of the system against the given specification. We present a logic-based formalism for specifying learning-enabled autonomous systems, which involve components based on neural networks. The formalism is based on first-order past time temporal logic that uses predicates for denoting events. We have applied the formalism successfully to two complex use cases

Computing the shortest elementary flux modes in genome-scale metabolic networks

This article is available open access through the publisher’s website through the link below. Copyright @ The Author 2009.Motivation: Elementary flux modes (EFMs) represent a key concept to analyze metabolic networks from a pathway-oriented perspective. In spite of considerable work in this field, the computation of the full set of elementary flux modes in large-scale metabolic networks still constitutes a challenging issue due to its underlying combinatorial complexity. Results: In this article, we illustrate that the full set of EFMs can be enumerated in increasing order of number of reactions via integer linear programming. In this light, we present a novel procedure to efficiently determine the K-shortest EFMs in large-scale metabolic networks. Our method was applied to find the K-shortest EFMs that produce lysine in the genome-scale metabolic networks of Escherichia coli and Corynebacterium glutamicum. A detailed analysis of the biological significance of the K-shortest EFMs was conducted, finding that glucose catabolism, ammonium assimilation, lysine anabolism and cofactor balancing were correctly predicted. The work presented here represents an important step forward in the analysis and computation of EFMs for large-scale metabolic networks, where traditional methods fail for networks of even moderate size. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online (http://bioinformatics.oxfordjournals.org/cgi/content/full/btp564/DC1).Fundação Calouste Gulbenkian, Fundação para a Ciência e a Tecnologia (FCT) and Siemens SA Portugal