Reliability in terms of functional properties from the safety-liveness spectrum is an indispensable requirement of low-level operating-system (OS) code. However, with evermore complex and thus less predictable hardware, quantitative and probabilistic guarantees become more and more important. Probabilistic model checking is one technique to automatically obtain these guarantees. First experiences with the automated quantitative analysis of low-level operating-system code confirm the expectation that the naive probabilistic model checking approach rapidly reaches its limits when increasing the numbers of processes. This paper reports on our work-in-progress to tackle the state explosion problem for low-level OS-code caused by the exponential blow-up of the model size when the number of processes grows. We studied the symmetry reduction approach and carried out our experiments with a simple test-and-test-and-set lock case study as a representative example for a wide range of protocols with natural inter-process dependencies and long-run properties. We quickly see a state-space explosion for scenarios where inter-process dependencies are insignificant. However, once inter-process dependencies dominate the picture models with hundred and more processes can be constructed and analysed.

Newsletter des Sonderforschungsbereichs 912 "Highly Adaptive Energy-Efficient Computing" (HAEC)

The number of secure data streams a relay-assisted interference channel can support has been an intriguing problem. The problem is not solved even for a fundamental scenario with a single antenna at each transmitter, receiver and relay. In this paper, we study the achievable secure degrees of freedom of instantaneous relay-assisted interference channels with real and complex coefficients. The study of secure degrees of freedom with complex coefficients is not a trivial multiuser extension of the scenarios with real channel coefficients as in the case for the degrees of freedom, due to secrecy constraints. We tackle this challenge by jointly designing the improper transmit signals and widely-linear relay processing strategies.

In this paper, we analyze the four-node relay wiretap channel, where the relay performs amplify-and-forward. There is no direct link between transmitter and receiver available. The transmitter has multiple antennas, which assist in securing the transmission over both phases. In case of full channel state information (CSI), the transmitter can apply information leakage neutralization in order to prevent the eavesdropper from obtaining any information about the signal sent. This gets more challenging, if the transmitter has only an outdated estimate of the channel from the relay to the eavesdropper. For this case, we optimize the worst case secrecy rate by choosing intelligently the beamforming vectors and the power allocation at the transmitter and the relay.

La présente recherche collaborative vise à étudier les pratiques de lecture à haute voix d’enseignantes expertes et leur influence sur le développement de l’habileté des élèves du préscolaire à faire des inférences. Plus précisément, nous décrivons les interventions, lors des lectures à haute voix, de quatre enseignantes expertes que nous avons formées pour travailler la compréhension inférentielle et les comparons à celles de deux enseignantes expertes non formées (objectif 1). Puis, nous examinons l’influence de leurs pratiques de lecture à haute voix sur le développement de l’habileté à faire des inférences de leurs élèves (n=92) (objectif 2). Enfin, nous nous intéressons, à titre exploratoire, au potentiel de la recherche collaborative comme voie de développement professionnel des enseignants (objectif 3). Afin d’atteindre nos objectifs, nous avons observé les enseignantes à quatre reprises, lors de lectures d’albums de littérature de jeunesse. Les données obtenues à partir de ces pratiques observées ont été complétées par celles issues des pratiques déclarées des enseignantes pour toute la durée de la recherche (neuf semaines). De plus, nous avons évalué l’habileté à réaliser des inférences des élèves de ces six enseignantes à deux reprises, au début et à la fin de la recherche. Finalement, les enseignantes ont rempli deux questionnaires écrits sur l’impact de cette recherche sur leurs pratiques, l’un à la fin de la recherche et l’autre deux ans après celle-ci. Nos résultats indiquent que si toutes les enseignantes travaillaient les inférences, il existe cependant des différences notables dans leur façon de mener ce travail. Trois des enseignantes formées (enseignantes 1, 2 et 3) ont majoritairement privilégié la co-élaboration du sens des épisodes implicites et se sont montrées très efficaces pour soutenir leurs élèves dans ce travail de construction du sens. L’autre enseignante formée (enseignante 4), en raison d’une appropriation difficile du contenu de la formation, n’est pas parvenue à offrir à ses élèves un étayage adéquat, malgré ses nombreuses tentatives pour les amener à faire des inférences. Les enseignantes non formées (enseignantes 5 et 6) ont, quant à elles, misé plus fréquemment sur la transmission du sens des épisodes implicites et ont également soutenu moins efficacement leurs élèves dans l’élaboration du sens. Ces différences dans la façon de travailler les inférences se sont répercutées sur la progression des élèves entre le début et la fin de la recherche. Ceux des enseignantes 1, 2 et 3 obtiennent des résultats significativement supérieurs à ceux des trois autres enseignantes. Ainsi, il ne suffit pas de travailler les inférences lors des lectures à haute voix pour assurer la progression des élèves. D’autres facteurs revêtent aussi une grande importance : le choix d’oeuvres de qualité, l’engagement des élèves dans les discussions pour co-élaborer le sens et l’étayage adéquat de l’enseignant. Enfin, il semblerait que l’activité réflexive suscitée lors d’une participation à une recherche collaborative et le soutien offert par l’étudiante-chercheuse aient donné aux enseignantes la possibilité d’apporter des changements durables dans leurs pratiques. En ce sens, la recherche collaborative paraît être une voie prometteuse pour contribuer au développement professionnel des enseignants. / This collaborative research is an attempt to study expert teachers' reading aloud practices and their impact on the development of preschool students’ ability to make inferences. First, the interventions of four expert teachers specifically trained to work inferences while reading aloud are described and compared with those of two non trained expert teachers (objective 1). Next, the impact of all teachers’ practices on the development of their students’ ability to make inferences (n=92) is examined (objective 2). Finally, we look into collaborative research as a way to support professional development for teachers (objective 3). In order to attain our objectives, we observed participant teachers four times while they were reading children’s books. Data gathered from those observations were completed with other data provided by the teachers about their practices over a nine-week period. Moreover, the ability of the students to make inferences was assessed twice: once at the beginning and once at the end of the research. Teachers also completed two written questionnaires, one at the beginning and the other 2 years after the end of this research, concerning the impacts of their participation in this research on their practices. While all teachers worked inferences with their students, our results showed that there are significant differences in the way they do it. Three of the trained teachers (number 1, 2, and 3) predominantly put emphasis on co-elaboration of the implicit episodes’ meaning and gave their students appropriate scaffolding. Because she found it difficult to assimilate training contents, the other trained teacher (number 4) failed - not without numerous attempts - to offer the same kind of scaffolding. As for the two non trained teachers (number 5 and 6), they gave preference to the transmission of the implicit episodes’ meaning, and supported their students less efficiently when they tried to elaborate it. The differences in how the work on inferences was done had an impact on students’ progression from the beginning to the end of the research. Three of the trained teachers’ students had significantly superior results in comparison to the others’. Therefore, a specific work on inferences only does not ensure that students will make progress. There are other important contributing factors: choosing quality books, students’ involvement in discussions in order to co-elaborate the text’s meaning, and appropriate scaffolding from the teacher. Finally, according to our results, a participation in a collaborative research, which promotes reflexivity and offers coaching, seems to give the teachers the opportunity to bring about long-term changes in their practices. In consequence, a participation in that type of research appears to contribute to teachers’ professional development.

No description available.

Secret key generation from reciprocal multi-antenna channels is an interesting alternative to cryptographic key management in wireless systems without infrastructure access. In this work, we study the secret key rate for the basic source model with a MIMO channel. First, we derive an expression for the secret key rate under spatial correlation modelled by the Kronecker model and with spatial precoding at both communication nodes. Next, we analyze the result for uncorrelated antennas to understand the optimal precoding for this special case, which is equal power allocation. Then, the impact of correlation is characterized using Majorization theory. Surprisingly for small SNR, spatial correlation increases the secret key rate. For high SNR, the maximum secret key rate is achieved for uncorrelated antennas. The results indicate that a solid system design for reciprocal MIMO key generation is required to establish the secret key rate gains.

No description available.

In this Master’s thesis, I document my experience working with members of the W̱SÁNEĆ Nation in their efforts to revitalize the reef net fishery. As part of this research project, I interviewed W̱SÁNEĆ community members, and I created a digital map of reef net fishing locations (SWELSWÁLET). In each of these interviews, different W̱SÁNEĆ community members chose to frame reef net fishing differently, and they highlighted specific and unique “alternative political approaches” toward W̱SÁNEĆ cultural resurgence (Kew & Miller 1999:58-59). Despite these differences, each W̱SÁNEĆ community member that I interviewed believed that reef net fishing is something that “needs to be shared” (XA’LATE, pers. comm., June 14, 2016). In Chapter 1, I explore the variations in what specific W̱SÁNEĆ community members want shared. In Chapters 2 and 3, however, I examine the delicate cultural, political, and legal contexts that have made sharing a complicated process. In Chapter 2, I analyze how the BC Treaty Process (BCTP) has exacerbated conflicts among First Nations in British Columbia. Further, I discuss the impact that these conflicts have had on how the W̱SÁNEĆ Nation shares information with their intranational and international neighbours. In Chapter 3, I explore how my misaligned expectations of knowledge sharing in collaborative community-based research—as a white settler man—clashed with “the values and beliefs, practices and customs of [the W̱SÁNEĆ Nation]” (L. Smith 2012:15-16; Lassiter 2005). I also make recommendations for how settler researchers in the future should proceed with research projects in these contexts. / Graduate / 2019-12-06

SILVEIRA, Selene Maria Penaforte. A gestão para a inclusão: uma pesquisa-ação colaborativa no meio escolar. 2009. 280 f. Tese (Doutorado em Educação) – Universidade Federal do Ceará, Faculdade de Educação, Programa de Pós-Graduação em Educação Brasileira Fortaleza-CE, 2009. / Submitted by Liliane oliveira (morena.liliane@hotmail.com) on 2012-07-27T15:01:06Z No. of bitstreams: 1 2009_TESE_SMPSILVEIRA.pdf: 1377981 bytes, checksum: 828ed96f9385cc7b86da62e353db527a (MD5) / Approved for entry into archive by Maria Josineide Góis(josineide@ufc.br) on 2013-11-14T14:10:15Z (GMT) No. of bitstreams: 1 2009_TESE_SMPSILVEIRA.pdf: 1377981 bytes, checksum: 828ed96f9385cc7b86da62e353db527a (MD5) / Made available in DSpace on 2013-11-14T14:10:15Z (GMT). No. of bitstreams: 1 2009_TESE_SMPSILVEIRA.pdf: 1377981 bytes, checksum: 828ed96f9385cc7b86da62e353db527a (MD5) Previous issue date: 2009 / The recent educational demands point to the need of change in schools concerning the care of students, taking into account their individual needs and singularities. Regarding this change, the role of the principal is identified as a fundamental role in the upcoming of inclusive schools, requiring new abilities, knowledge and development in order to face the challenge of managing those schools. This work encompasses a research experience developed throughout a partnership with a school, striving to build up elements of reference to the management of the school regarding the diversity issue. In order to accomplish this study we have done a comprehensive bibliographical account involving theoretical axis and researches on the themes of school, inclusion and the new kinds of school organization facing diversity. Moreover, studies on culture, diversity, difference, and the principles implied in change theory and the foundations of management towards an inclusive school were added in the bibliographical research. The research itself aimed to develop, in partnership with a city public school, an intervention program considering the school management regarding diversity issues, having as a starting point the constitution of a co-participative management. The methodology used was the collaborative action-research which is featured by the sharing of the knowledge among all participants of the process, so that, together, they can change an initial situation into a better one. The study lasted two years and a half and the results showed that a shared management may be beneficial to the constitution of an inclusive school. It is fundamental, though, that the school members learn to work together and seek, increasingly, the improvement of collaborative practices. In the specific school researched, we have considered as a key issue, the changing of management practices, specifically the way the guidance of daily actions was developed. This guidance allowed the improvement of some changing issues: the introduction of a collaborative action between the coordination and the teachers, mainly those teachers who were coached by members of the research “Learning Management in Diversity” team; the reorganization of planning actions; the reinforcement of actions in the issue of participative management; investment in the diversification of pedagogical equipment and in school facilities; the systematization of the actions of the director’s board throughout the sharing of the decision taking process; and the investment in the development of teachers and coordinators. The changes occurred along the research process lead us to say that the management model adopted in the school did not suffice the need for change from a traditional cultural pedagogical practice still prevalent. The changes occurred did not diverge from homogenous teaching practice neither guaranteed nor corresponded with a model that moved towards the constitution of an inclusive identity that devised the improvement of teaching patterns offered to the students / As demandas educacionais atuais apontam para a necessidade de mudanças na escola para o atendimento aos alunos, levando em conta suas singularidades e necessidades individuais. Para essas mudanças, o papel do diretor é identificado como fundamental na constituição de escolas inclusivas requerendo novas habilidades, conhecimentos e formação que atenda o desafio de gerir essas escolas. Este trabalho se constituiu em uma experiência de pesquisa desenvolvida em parceria com uma escola, buscando construir elementos de referência para a organização e gestão da escola na diversidade. Para a realização desse estudo, empreendemos uma revisão bibliográfica contemplando eixos teóricos e pesquisas realizadas acerca da discussão sobre a escola, a inclusão e as novas formas de organização frente à diferença e a diversidade além dos estudos que discutem sobre a cultura, educação e diferença e os pressupostos implicados na teoria da mudança e nos fundamentos de uma gestão para a escola inclusiva. A pesquisa teve por objetivo desenvolver, em parceria com uma escola publica municipal, uma experiência de intervenção que considerasse a gestão da aprendizagem na diversidade, tendo como ponto de partida à constituição de uma gestão co-participativa. A metodologia utilizada foi a pesquisa-ação colaborativa que se caracteriza pelo compartilhamento do saber na qual todos os participantes do processo, juntos, promovem ações para transformar uma situação inicial num estado desejado. O estudo teve duração de dois anos e meio e os resultados mostraram que a gestão compartilhada é benéfica à constituição da escola inclusiva sendo fundamental que os membros da escola aprendam a trabalhar junto e busquem, cada vez mais, o aperfeiçoamento de práticas de colaboração. Na escola pesquisada, consideramos como ponto fundamental para a mudança na gestão, à forma como foi desenvolvido o acompanhamento das ações cotidianas. Esse acompanhamento permitiu o avanço em alguns pontos que destacamos na seqüência: a interiorização da cultura de cooperação entre a gestão da escola e os professores, especialmente aqueles que foram acompanhados por membros da pesquisa Gestão da Aprendizagem na Diversidade; a criação da cultura do acolhimento a todos os alunos por parte da gestão da escola; a reorganização das ações de planejamento; reforço das ações no âmbito da gestão participativa; investimento na diversificação dos equipamentos pedagógicos e na infra-estrutura da escola; a sistematização das ações da direção através da partilha e reciprocidade na tomada de decisões; e investimento na formação dos professores e membros a equipe de gestão. As mudanças acontecidas ao longo da pesquisa nos impulsionam a dizer que o modelo de administração adotado na escola não foi suficiente para provocar a mudança da cultura pedagógica tradicional ainda prevalecente. As transformações ocorridas não romperam totalmente com os padrões de ensino homogêneos e nem garantiram e corresponderam a um movimento efetivo na constituição de uma identidade inclusiva própria bem como na melhoria dos padrões de ensino ao alcance de todos os alunos