Algorithms for finding coalitions exploiting a new reciprocity condition

in Logic Journal of the IGPL (2009), 17(3), 273297

We introduce a reciprocity criterion for coalition formation among goal-directed agents, which we call the indecomposable do-ut-des property. It refines an older reciprocity property, called the do-ut-des ... [more ▼]

We introduce a reciprocity criterion for coalition formation among goal-directed agents, which we call the indecomposable do-ut-des property. It refines an older reciprocity property, called the do-ut-des or give-to-get property by considering the fact that agents prefer to form coalitions whose components cannot be formed independently. A formal description of this property is provided as well as an analysis of algorithms and their complexity. We provide an algorithm to decide whether a coalition has the desired property, and we show that the problem to verify whether a single coalition satisfies the property is tractable. Moreover, we provide an algorithm to search all the sub-coalitions of a given coalition satisfying the new property. Even if this problem is not computationally tractable, we show that in several cases, also the complexity of this problem may decrease considerably. [less ▲]

On noncommutative deformations, cohomology of color-commutative algebras and formal smoothness

Doctoral thesis (2009)

The main topic under study in the present work is the deformation theory of color algebras. Color algebras are generalized analogues of associative superalgebras, where the underlying grading can be over ... [more ▼]

The main topic under study in the present work is the deformation theory of color algebras. Color algebras are generalized analogues of associative superalgebras, where the underlying grading can be over an arbitrary abelian group and the Koszul sign is replaced by a bicharacter from the group into the base ring. A special case of particular interest are color-commutative algebras, which satisfy a commutation identity similar to (but much more general than) supercommutative algebras. Examples of color-commutative algebras include commutative and supercommutative superalgebras, the quaternions and para-quaternions, full matrix algebras over suitable base rings, Clifford algebras, and group rings over certain nonabelian groups. In the present work, Gerstenhaber-type formal deformations of these algebras are studied. In doing so, we extend previous work by Scheunert and provide a different approach to noncommutative deformation theory as introduced by Pinczon and Nadaud. In preparation of developing deformation theory for color algebras, we adapt a number of tools from ungraded Hochschild theory to our setting: among them, we derive an adapted Ext-functor, a color Gerstenhaber bracket, twisted graded versions of pre-Lie-algebras and pre-Lie-systems and colored analogs of the classical results linking infinitesimal deformations and obstructions to extension of deformations to second and third Hochschild cohomology. Additionally, we discuss the impact of some decisions in the construction of the trivial deformation object (color power series rings of given degree) on the resulting deformation theory. Finally, color-commutative deformations of color-commutative algebras are discussed and a suitable version of Harrison cohomology is developed. Also, the problem of classifying the color-commutative structures compatible with a given ungraded algebra is discussed and one nontrivial example is studied in detail. In support of all of these efforts, a number of structure theorems about color-commutative algebras are shown. [less ▲]

SESAME: a Model-Driven Process for the Test Selection of Small-size Safety-related Embedded Software

Doctoral thesis (2009)

Embedded software applications are part of our daily lives, some of which have safety implications on human beings. It is thus important to trust this type of software. In our industrial context, testing ... [more ▼]

Embedded software applications are part of our daily lives, some of which have safety implications on human beings. It is thus important to trust this type of software. In our industrial context, testing is the most widely-spread technique used for that purpose. The state of practice is divided in two main categories. Explicit test selection techniques that enumerate the test cases to be exercised, but do not offer large coverage of the system’s behavior; and implicit techniques that encompass fully automated test generation techniques, which tend to hide the test selection information from engineers. The problem that we aim at solving in this thesis is the definition of a test selection approach that is capable of helping test engineers to better reach a delimited and verifiable test set with respect to some given test requirements and project specificities taking into account different test stakeholders.<br /><br />The SESAME process is composed of the four following tasks: specification of the system for testing purposes; specification of a test selection that constrains the system specification; evaluation of the test selection; generation of test cases derived from the constrained system specification. As a validation of our approach, we apply the SESAME process to a case study taken from an industrial project. This industrial application has shown the applicability of our approach on a small-size safety-related embedded system. [less ▲]

Working Memory and Learning A 3-Year Longitudinal Study of Children Growing Up In a Multilingual Environment

Doctoral thesis (2009)

This thesis presents the findings of a 3-wave, latent variable longitudinal study, exploring variations and the development of working memory in young children and its contributions to learning in the key ... [more ▼]

This thesis presents the findings of a 3-wave, latent variable longitudinal study, exploring variations and the development of working memory in young children and its contributions to learning in the key domains of language, literacy, and mathematics. A sample of 119 Luxembourgish children, learning German and French as secondary languages, were followed from kindergarten to second grade and completed multiple assessments of working memory, short-term memory, phonological awareness, fluid intelligence, vocabulary, language comprehension, foreign language knowledge, reading, spelling, and mathematics. Results indicate that relations between the measures were best characterized by a model consisting of two related but separable constructs - corresponding to shortterm storage and a central executive - that were highly stable across the years. Whereas verbal short-term memory was more specifically linked to early language development and vocabulary in particular, the central executive appeared to support learning in a wide range of domains, including language comprehension, literacy, and mathematics. The findings reinforce previous evidence indicating that verbal short-term memory is one of the main contributors to vocabulary development by supporting the formation of stable phonological representations of new words in long-term memory. Furthermore, the findings fit well with the position that the central executive makes general rather then specific contributions to learning - possibly in terms of an attentional control system that actively maintains crucial information and regulates controlling processes during complex cognitive activities. In conclusion, the findings indicate that different components of the working memory system can be reliably assessed in children as young as 5; that individual differences in these abilities are highly stable over time; and that working memory assessments are predictive of future learning in key academic domains. This reinforces the value of early screening of working memory abilities to identify children who are at a present and future educational risk. [less ▲]

Corpus-informed EAP course design: a study of lecture functions

Scientific Conference (2009, May)

Increasing student and lecturer mobility along with the spread of English as an academic lingua franca (Mauranen, 2006) means a growing number of non-native speaker lecturers are delivering at least some ... [more ▼]

Increasing student and lecturer mobility along with the spread of English as an academic lingua franca (Mauranen, 2006) means a growing number of non-native speaker lecturers are delivering at least some lectures in English. Well-designed English for Academic Purposes (EAP) courses can be valuable in offering the language input these lecturers are most likely to need for communication within this specific academic context. The creation of corpora containing lectures such as the BASE (British Academic Spoken English) Corpus, MICASE (The Michigan Corpus of Academic Spoken English) and the T2K-SWAL (TOEFL 2000 Spoken and Written Academic Language) Corpus plays an important role in allowing us to adopt a corpus-informed approach to course design and thus tailor courses to lecturers’ specific needs. To date, most corpus-based research on lectures has been based on the American corpora (MICASE and T2K-SWAL) and has had a quantitative bias, investigating the frequency and functions of lexical bundles (e.g. Biber & Barbieri, 2007), discourse markers (e.g. Crawford Camiciottoli, 2004) and evaluative language (e.g. Swales & Burke, 2003). Discourse organisation (e.g. Nesi & Basturkmen, 2006; Thompson, 2003) and the oral-literate characteristics of lectures (e.g. Csomay, 2006) have also been relatively well explored. However, notwithstanding these significant contributions to EAP and the more comprehensive descriptions by Biber (2006) and Crawford Camiciottoli (2007) much remains to be done to obtain a more detailed linguistic picture of lectures. This paper uses data from 12 BASE lectures from various disciplines to provide an overview of attested language functions (e.g. informing, interacting, organising discourse, class management) used in achieving some of the main purposes of lectures (i.e. knowledge transfer, facilitating learning and the socialisation of students into disciplinary communities). Informed by insights from both linguistic and pedagogic research, this functional framework derives from a careful study of whole texts from which larger stretches of speech are assigned to particular functional categories on the basis of lexico-grammatical features, an understanding of the text and generic knowledge (Dudley-Evans, 1994). Biber, D. (2006). University language: a corpus-based study of spoken and written registers. Studies in Corpus Linguistics 23. Amsterdam: John Benjamins Publishing Company. Biber, D. & Barbieri, F. (2007). Lexical bundles in university spoken and written registers. English for Specific Purposes, 26, 263-286. Crawford Camiciottoli, B. (2004). Walking on unfamiliar ground: interactive discourse markers in guest lectures. In Partington, A., Morley, J., Haarman, L. (Eds.). (pp. 91-106). Corpora and context. Bern: Peter Lang. Crawford Camiciottoli, B. (2007). The language of business studies lectures. Amsterdam: John Benjamins. Csomay, E. (2006). Academic talk in American university classrooms: crossing the boundaries of oral-literate discourse? Journal of English for Academic Purposes, 5, 117-135. Dudley-Evans, T. (1994). Genre analysis: an approach to text analysis for ESP. In Coulthard, M. (Ed.). Advances in written text analysis. (pp. 219-228). London: Routledge. Mauranen, A. (2006). Spoken discourse, academics and global English: a corpus perspective. In Hughes, R. (Ed.). Spoken English, TESOL and applied linguistics. (pp. 143-158). Basingstoke: Palgrave MacMillan. Nesi, H. & Basturkmen, H. (2006). Lexical bundles and discourse signalling in academic lectures. International Journal of Corpus Linguistics, 11 (3), 283-304. Swales, J. M. & Burke A. (2003). “It’s really fascinating work”: differences in evaluative adjectives across academic registers. In Leistyna P. & Meyer, C. F. (Eds.). Language and comparisons: Studies in Practical Linguistics, 46. (pp. 1-18). Amsterdam: Rodopi. Thompson, S. E. (2003). Text-structuring metadiscourse, intonation and the signalling of organisation in academic lectures. Journal of English for Academic Purposes, 2, 5-20. [less ▲]

Fehlt es Cyberbullies an Empathie? Aktuelle Befunde zur Rolle des Mitgefühls

Scientific Conference (2009, May)

La construction de parcours innovants. Étude menée auprès d’opérateurs de niveau V du secteur textile

Scientific Conference (2009, May)

Erfolgreiches Lieferantenmanagement durch eindeutige Schnittstellendefinition

Book published by TÜV Media (2009)

In schlanken Werken montieren externe Dienstleister ausgewählte Baugruppen und liefern sie direkt an die Hauptmontagelinie. Dabei sind zahlreiche technische und organisatorische Schnittstellen zu ... [more ▼]

In schlanken Werken montieren externe Dienstleister ausgewählte Baugruppen und liefern sie direkt an die Hauptmontagelinie. Dabei sind zahlreiche technische und organisatorische Schnittstellen zu definieren, um den Wissenstransfer in beide Richtungen effektiv und sicher zu gestalten und dabei gleichzeitig das Know-how beider Seiten zu schützen. Dieser Beitrag beschreibt exemplarisch erfolgreich angewandte Methoden zur Einbindung externer Dienstleister in mehreren Werken in der Automobilindustrie. [less ▲]

Wie kommen Diagnosen bzw. Prognosen zustande? Analyse der kognitiven Prozesse von Therapeuten

Presentation (2009, May)

Une approche adaptative pour la recherche d'information sur le web

Doctoral thesis (2009)