Reset complexity of ideal languages over a binary alphabet

We prove PSPACE-completeness of checking whether a given ideal language serves as the language of reset words for some automaton with at most four states over a binary alphabet. © IFIP International Federation for Information Processing 2017

"5 Days in August" – How London Local Authorities used Twitter during the 2011 riots

© IFIP International Federation for Information Processing 2012This study examines effects of microblogging communications during emergency events based on the case of the summer 2011 riots in London. During five days in August 2011, parts of London and other major cities in England suffered from extensive public disorders, violence and even loss of human lives. We collected and analysed the tweets posted by the official accounts maintained by 28 London local government authorities. Those authorities used Twitter for a variety of purposes such as preventing rumours, providing official information, promoting legal actions against offenders and organising post-riot community engagement activities. The study shows how the immediacy and communicative power of microblogging can have a significant effect at the response and recovery stages of emergency events

A mérnöki szemlélet legfőbb jellegzetessége, hogy megoldásokat keres – Interjú dr. Csáki Csaba egyetemi docenssel, a Budapesti Corvinus Egyetem Adatelemzési és Informatikai Intézetének munkatársával

2023. szeptember 5-7 között rendezték az IFIP (International Federation for Information Processing) eGov-CeDEM-ePart éves nemzetközi konferenciáját, ami az információs technológiák közpolitikai használatáról és szabályozásáról szólt. A konferencia házigazdája dr. Csáki Csaba egyetemi docens volt, akit a konferencia mellett az info-kommunikációs technológiák jelenlegi állásáról is kérdeztünk

Conformance relations for distributed testing based on CSP

Copyright @ 2011 Springer Berlin HeidelbergCSP is a well established process algebra that provides comprehensive theoretical and practical support for refinement-based design and verification of systems. Recently, a testing theory for CSP has also been presented. In this paper, we explore the problem of testing from a CSP specification when observations are made by a set of distributed testers. We build on previous work on input-output transition systems, but the use of CSP leads to significant differences, since some of its conformance (refinement) relations consider failures as well as traces. In addition, we allow events to be observed by more than one tester. We show how the CSP notions of refinement can be adapted to distributed testing. We consider two contexts: when the testers are entirely independent and when they can cooperate. Finally, we give some preliminary results on test-case generation and the use of coordination messages. © 2011 IFIP International Federation for Information Processing

Error-free affine, unitary, and probabilistic OBDDS

© IFIP International Federation for Information Processing 2018. We introduce the affine OBDD model and show that zero-error affine OBDDs can be exponentially narrower than bounded-error unitary and probabilistic OBDDs on certain problems. Moreover, we show that Las Vegas unitary and probabilistic OBDDs can be quadratically narrower than deterministic OBDDs. We also obtain the same results for the automata versions of these models

On dynamical probabilities, or: how to learn to shoot straight

© IFIP International Federation for Information Processing 2016.In order to support, for example, a quantitative analysis of various algorithms, protocols etc. probabilistic features have been introduced into a number of programming languages and calculi. It is by now quite standard to define the formal semantics of (various) probabilistic languages, for example, in terms of Discrete Time Markov Chains (DTMCs). In most cases however the probabilities involved are represented by constants, i.e. one deals with static probabilities. In this paper we investigate a semantical framework which allows for changing, i.e. dynamic probabilities which is still based on time-homogenous DTMCs, i.e. the transition matrix representing the semantics of a program does not change over time

Service repository for cloud service consumer life cycle management

© IFIP International Federation for Information Processing 2015. With rapid uptake of various types of cloud services many organizations are facing issues arising from their dependence on externally provided cloud services. In order to enable operation in this rapidly evolving environment, end user organizations need new methods and tools that support entire life-cycle of cloud services from the perspective of service consumers. Service repositories play a key role in supporting service consumer SDLC (Systems Development Life-Cycle) maintaining information that is used during the various life-cycle phases. In this paper we briefly describe service consumer SDLC and propose a design of service repository that supports information requirements throughout the service life-cycle

The Challenges of Creating Connections and Raising Awareness: Experience from UCLIC

With current disciplinary structures and academic priorities, Human-Computer Interaction faces ongoing challenges: is it a discipline in its own right, or simply a sub-discipline of computer science, psychology or design? Is it a science or engineering discipline? Should it concern itself with developing theory or improving practice? UCLIC aims to find appropriate middle ways on such questions: it conducts scientifically-based HCI research with a view to improving practice, and thus have an impact on society. It is based in the disciplines of Psychology and Computer Science and promotes participation across the disciplines. Research and teaching cover cognitive, affective, physical, social and technical aspects of interactive system design and use. © IFIP International Federation for Information Processing 2007

Reproducibility of experiments in recommender systems evaluation

© IFIP International Federation for Information Processing 2018 Published by Springer International Publishing AG 2018. All Rights Reserved. Recommender systems evaluation is usually based on predictive accuracy metrics with better scores meaning recommendations of higher quality. However, the comparison of results is becoming increasingly difficult, since there are different recommendation frameworks and different settings in the design and implementation of the experiments. Furthermore, there might be minor differences on algorithm implementation among the different frameworks. In this paper, we compare well known recommendation algorithms, using the same dataset, metrics and overall settings, the results of which point to result differences across frameworks with the exact same settings. Hence, we propose the use of standards that should be followed as guidelines to ensure the replication of experiments and the reproducibility of the results

PVInGrid: A distributed infrastructure for evaluating the integration of photovoltaic systems in smart grid

© IFIP International Federation for Information Processing 2017 Published by Springer International Publishing AG 2017. All Rights Reserved. Planning and developing the future Smart City is becoming mandatory due to the need of moving forward to a more sustainable society. To foster this transition an accurate simulation of energy production from renewable sources, such as Photovoltaic Panels (PV), is necessary to evaluate the impact on the grid. In this paper, we present a distributed infrastructure that simulates the PV production and evaluates the integration of such systems in the grid considering data provided by smart-meters. The proposed solution is able to model the behaviour of PV systems solution exploiting GIS representation of rooftops and real meteorological data. Finally, such information is used to feed a real-time distribution network simulator