Nos travaux portent sur la conception et la réalisation d'un environnement interactif et multi-utilisateurs à exécution adaptative. Nous nous plaçons dans un cadre générique, pour définir les mécanismes de gestion des interactions et de l'exécution adaptative, ainsi que la méthodologie permettant d'appliquer ces mécanismes à un domaine donné. Nous utilisons cette méthodologie pour produire un environnement prototype, dédié à la formation à distance et semi-présentielle. Un point-clé de notre approche est la théorie de la distance transactionnelle, qui représente la distance ressentie par les participants à une interaction. Notre principal objectif est la réduction de cette distance en concevant un environnement qui permette de jouer sur les trois éléments constituant cette distance : le dialogue, la structure et l'autonomie. Le travail sur le dialogue consiste à optimiser les interactions, en proposant des modes de communications variés, en multipliant les opportunités d'échange et en augmentant leur qualité. Le travail sur la structure consiste à améliorer la flexibilité des interactions. Enfin, le travail sur l'autonomie consiste à offrir aux participants une certaine indépendance vis-à-vis de la structure. Pour cela, nous proposons une combinaison de technologies issues de la narration interactive, de la contextualisation et de la gestion des ambiguïtés pour construire un modèle de scénarisation des interactions. Le principe est de découper des séquences d'interactions en unités d'activité et de composer des scénarios à partir de ces unités. Une unité d'activité est appelée situation : elle peut être élémentaire ou bien composée elle-même d'autres activités. Les mécaniques de narration interactive nous permettent de piloter de manière adaptative le déroulement des scénarios conçus de cette façon, en laissant les utilisateurs libres de s'en détacher, tout en garantissant une cohérence globale et le respect de règles prédéfinies. La prise en charge du contexte et l'analyse a posteriori des sessions d'interactions permettent d'évaluer la qualité d'un scénario et de mettre en place un cycle d'évolution permanent de ces scénarios. Ces mécanismes sont présentés à travers le développement d'un environnement prototype de formation à distance. Ce prototype comporte également des outils que nous proposons pour mettre en place de nouvelles interactions à distance. Ces outils sont basés sur l'utilisation de gestes, de la voix et l'exploitation du contexte. Ils s'appuient sur des approches inspirées des réseaux sociaux et de la gamification, pour proposer des interactions variées et favoriser les échanges. Le prototype que nous proposons ne requiert pratiquement aucun pré-requis matériel ou logiciel et s'affranchit de toute technologie propriétaire. Nous présentons également une étude comparative des environnements existants qui illustre la plus-value de notre proposition, qui se présente comme un complément aux environnements de formation classiques les plus répandus. Notre prototype a fait l'objet de tests en comité restreint et en simulation de montée en charge. Des utilisations en situation réelle de formation sont en cours de préparation. / Our works focus on the conception and development of an interactive and adaptive multi-users environment. We define mechanisms to handle distant interactions and adaptive execution in a generic scope, and the methodology to apply those mechanisms to a given domain. We use this methodology to produce a prototype environment dedicated to distant and semi-distant learning. One key aspect of our approach is the concept of transactional distance, which represent the distance that users feel when taking part into distant interaction. Our main objective is to reduce this distance through the conception of an environment that can allow us to impact each of the three elements defining it : dialogue, structure, and independence. Enhancing the dialogue means offering more various communication means, and improving their quality. Enhancing the structure means offering more flexibility. Finally, enhancing the independence means allowing users to divert from the structure. To achieve that, we propose to combine technologies from various domains such as interactive storytelling, context-awareness, and misunderstandings handling, to build a model for the conception of interactive scenarios. It consists in splitting interaction sequences into activity units, and building up scenarios from these units. One unit is called a situation, it can be basic or composed of other situations. The interactive storytelling mechanisms allow us to drive the execution of such scenarios in an adaptive way, giving users the freedom to divert from the structure, while guaranteeing the overall coherence of the execution. Moreover, the context-awareness and the analysis of the executions allow us to evaluate the quality of a scenario, and thus make it evolve between sessions. We call this mechanism the scenario's life-cycle, and allows the scenarios to be constantly improved. Those mechanisms are presented through the development of a prototype e-learning environment. This prototype also contains several tools to enhance interactions. These tools are based on gesture, voice and context utilisation. They use principles inspired by social networks and gamification to offer varied interactions and promote knowledge sharing. The prototype we present comes with almost no hardware or software prerequisite, and is free of proprietary technology. We also present a comparative study about the main existing e-learning environment, to position our prototype, which is proposed as a complementary tool to existing learning management systems. Our prototype has been tested by a small number of users, and scalability has been tested through simulations. We are currently planning the use of our system in real-life situations.

En réponse à la demande croissante de performance par une grande variété d’applications (exemples : modélisation financière, simulation sub-atomique, bio-informatique, etc.), les systèmes informatiques se complexifient et augmentent en taille (nombre de composants de calcul, mémoire et capacité de stockage). L’accroissement de la complexité de ces systèmes se traduit par une évolution de leur architecture vers une hétérogénéité des technologies de calcul et des modèles de programmation. La gestion harmonieuse de cette hétérogénéité, l’optimisation des ressources et la minimisation de la consommation constituent des défis techniques majeurs dans la conception des futurs systèmes informatiques.Cette thèse s’adresse à un domaine de cette complexité en se focalisant sur les sous-systèmes à mémoire partagée où l’ensemble des processeurs partagent un espace d’adressage commun. Les travaux porteront essentiellement sur l’implémentation d’un protocole de cohérence de cache et de consistance mémoire, sur une architecture extensible et sur la méthodologie de validation de cette implémentation.Dans notre approche, nous avons retenu les processeurs 64-bits d’ARM et des co-processeurs génériques (GPU, DSP, etc.) comme composants de calcul, les protocoles de mémoire partagée AMBA/ACE et AMBA/ACE-Lite ainsi que l’architecture associée « CoreLink CCN » comme solution de départ. La généralisation et la paramètrisation de cette architecture ainsi que sa validation dans l’environnement de simulation Gem5 constituent l’épine dorsale de cette thèse.Les résultats obtenus à la fin de la thèse, tendent à démontrer l’atteinte des objectifs fixés / In response to the growing demand for performance by a wide variety of applications (eg, financial modeling, sub-atomic simulation, bioinformatics, etc.), computer systems become more complex and increase in size (number of computing components, memory and storage capacity). The increased complexity of these systems results in a change in their architecture towards a heterogeneous computing technologies and programming models. The harmonious management of this heterogeneity, resource optimization and minimization of consumption are major technical challenges in the design of future computer systems.This thesis addresses a field of this complexity by focusing on shared memory subsystems where all processors share a common address space. Work will focus on the implementation of a cache coherence and memory consistency on an extensible architecture and methodology for validation of this implementation.In our approach, we selected processors 64-bit ARM and generic co-processor (GPU, DSP, etc.) as components of computing, shared memory protocols AMBA / ACE and AMBA / ACE-Lite and associated architecture "CoreLink CCN" as a starting solution. Generalization and parameterization of this architecture and its validation in the simulation environment GEM5 are the backbone of this thesis.The results at the end of the thesis, tend to demonstrate the achievement of objectives

Syftet med denna litteraturstudie är att undersöka vilka strategier och metoder forskningen förespråkar för undervisningen i läsförståelse för att främja elevers utveckling. Vilka undervisningsmodeller förespråkar forskningen i undervisningen av läsförståelse? Resultatet i denna litteraturstudie visar att lä rares kunskap ä r en viktig faktor i undervisnigen fö r att eleverna ska nå framgång i sin läsförståelse. Resultatet visar också att det finns flera olika metoder och strategier som lärare kan använda sig av i sin undervisning för att skapa en utvecklande miljö som ger positiva effekter på elevernas läsförståelse. Forskare förespråkar den dialogiska undervisningen där läsförståelsestrategier och interaktion står i centrum.

Magister Psychologiae - MPsych / Alcohol remains the most commonly abused substance in South Africa and several studies have shown associations between alcohol use and risky sexual behaviours, which pose a risk of HIV infection. Research indicates that the age group of 15-24 years is a high risk group for HIV infection. This study aimed at examining the perceptions of alcohol as a risk factor to HIV infection amoungst a sample of university students.Specifically, this study tested the hypotheses that most students perceive that those who consume alcohol were more likely to engage in unprotected sex, sex with multiple partners, casual sex and transactional sex. The Information Motivation Behavioural(IMB) skills model provided the theoretical framework for the study. Using a quantitative research design, a survey questionnaire was used to collect the data. The sample consisted of 240 first year psychology students (192 females, 48 males). Data analyses indicated support for the hypotheses that alcohol consumption was perceived as high risk for unprotected sex, casual sex and sex with multiple partners. However, the data showed no support for the hypothesis of alcohol increasing the risk of transactional sex. The data also indicated that non-drinkers were more likely to perceive alcohol as a risk factor than drinkers. The recognition by students of alcohol as a risk factor for HIV infection provides an opportunity for raising awareness about safer sex practices at institutions of higher learning in South Africa.

Le 26 février 1929, le philosophe américain John Dewey prononce une conférence devant un public d’étudiants et d’enseignants dans lequel il se prononce nettement en faveur de la mise en place d’une science de l’éducation, dont il développe les principales caractéristiques. La décennie qui suit va alors s’avérer d’une grande richesse intellectuelle et voir Dewey travailler ardemment à l’approfondissement et à l’élargissement de sa réflexion philosophique en direction de nouveaux champs et de nouvelles problématiques. Paradoxalement, cette période est également celle où son œuvre éducative semble la moins bien connue, en comparaison de ses premiers travaux sur le sujet, qui contribuèrent à sa renommée précoce sur le plan international. L’ambition du présent travail est donc d’étudier la réflexion éducative qu’il mène dans cette période, à la lumière du renouveau qu’elle apporte dans la compréhension globale de son œuvre. A travers la science de l’éducation, l’enjeu est alors d’observer en quoi la réflexion éducative de Dewey est susceptible de rejoindre ses théories du social et de la connaissance afin de proposer un schème d’analyse cohérent, à même de nous aider à faire face à l’inquiétude d’un monde en perpétuelle évolution. / On November 26th 1929, American philosopher John Dewey gave an address to an audience comprising students and teachers, in which occasion he advocated for the development of a Science of education and described its main features. The following decade is then one of a great intellectual wealth and sees Dewey working hard to broaden and deepen the range of his philosophical thought towards new fields and new problems to deal with. Surprisingly enough, this period also seems to be one concerning which his contribution to education appears to be of less importance, when compared to his first achievements in the field which brought him an early and international fame. The scope of our paper is accordingly to study the educational thinking entertained by Dewey at that time, at the dawn of the renewed light it sheds over the comprehensive significance of his work. Through a Science of education, our aim is then to analyze how Dewey’s educational thinking may connect to his theories of science and society in order to provide a consistent scheme of analysis, which may reveal itself helpful in facing the inquietude of a world in constant evolution.

The study’s primary research interest is in the area of leadership and creativity. Investigating the literature indicates that there is a gap in knowledge regarding the effect of the Full Range of Leadership styles, especially the influence of transformational leadership on employees’ creative performance. Examining this relationship in different sectors (for example: public government sector); in different cultures (for example: Arab Islamic culture); and from multi-perspectives (for example: leaders and employees) is strongly encouraged by research. The Omani civil service sector was used as a case study, thus the aim of the study was to investigate the degree to which Omani civil service managers practised the Full Range of Leadership styles to influence employees’ creative performance. The study set six objectives which provided the foundation for the structure of the study and the way its research questions were formulated. Accordingly, the study methodology was designed in a way that points towards the achievement of the study objectives. The study adopted a mixed-methods research approach by combining survey questionnaires with semi-structured interviews. This triangulation technique was utilized to enable more accurate investigation and allow in-depth coverage of the issues examined. The probability sampling method as represented by the random sampling technique was adopted for this study and applied to the two groups of managers and employees. The total size of the managers’ sample was 269 participants, while the employees’ sample was 371 participants. In addition, 15 semi-structured interviews were conducted to supplement the quantitative results. The results of this study show that the Omani managers are performing both transformational and transactional leadership styles. Examining the relationship, the study confirms that there is an overall statistically significant relationship between managers’ use of transformational and transactional leadership styles and employees’ creative performance from both managers’ and employees’ perspectives. The results also reveal that Omani managers are infrequently practicing passive/avoidant leadership style and that this style does not contribute to the employees’ creative performance. Further, the study demonstrate that Omani managers’ personal characteristics have a slight effect on managers’ perceptions towards transformational leadership styles and do not have any impact on their perceptions toward employees’ creative performance. Finally, this study contributed to knowledge in several areas where scholars who are interested in investigating the relationship between leadership and creativity will find it valuable.

Orientador: Guido Costa Souza de Araújo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-22T08:27:32Z (GMT). No. of bitstreams: 1 Nicacio_DanielHenricusdeKnegtDutra_D.pdf: 2579331 bytes, checksum: b8e15a6f91203b98455f39d63d63a634 (MD5) Previous issue date: 2012 / Resumo: Sistemas de Memória Transacional em Software (MTS) têm sido usados como uma abordagem para melhorar o desempenho ao permitir a execução concorrente de blocos atômicos. Porém, em cenários com alta contenção, sistemas baseados em MTS podem diminuir o desempenho consideravelmente, já que a taxa de conflitos aumenta. Políticas de gerenciamento de contenção têm sido usadas como uma forma de selecionar qual transação abortar quando um conflito ocorre. No geral, gerenciadores de contenção não são capazes de evitar conflitos, tendo em vista que eles apenas selecionam qual transação abortar e o momento em que ela deve reiniciar. Como gerenciadores de contenção agem somente após a detecção de um conflito, é difícil aumentar a taxa de transações finalizadas com sucesso. Abordagens mais pró-ativas foram propostas, focando na previsão de quando uma transação deve abortar e atrasando o início de sua execução. Contudo, as técnicas pró-ativas continuam sendo limitadas, já que elas não substituem a transação fadada a abortar por outra transação com melhores probabilidades de sucesso, ou quando o fazem, dependem do sistema operacional para essa tarefa, tendo pouco ou nenhum controle de qual transação será a substituta. Esta tese apresenta o LUTS, Lightweight User-Level Transaction Scheduler, um escalonador de transação de baixo custo em nível de usuário. Diferente de outras técnicas, LUTS provê maneiras de selecionar outra transação a ser executada em paralelo, melhorando o desempenho do sistema. Nós discutimos o projeto do LUTS e propomos uma heurística dinâmica, com o objetivo de evitar conflitos, que foi construída utilizando os métodos disponibilizados pelo LUTS. Resultados experimentais, conduzidos com os conjuntos de aplicações STAMP e STMBench7, e executando nas bibliotecas TinySTM e SwissTM, mostram como nossa heurística para evitar conflitos pode melhorar efetivamente o desempenho de sistema de MTS em aplicações com alta contenção / Abstract: Software Transaction Memory (STM) systems have been used as an approach to improve performance, by allowing the concurrent execution of atomic blocks. However, under high-contention workloads, STM-based systems can considerably degrade performance, as transaction conflict rate increases. Contention management policies have been used as a way to select which transaction to abort when a conflict occurs. In general, contention managers are not capable of avoiding conflicts, as they can only select which transaction to abort and the moment it should restart. Since contention manager's act only after a conflict is detected, it becomes harder to effectively increase transaction throughput. More proactive approaches have emerged, aiming at predicting when a transaction is likely to abort, postponing its execution. Nevertheless, most of the proposed proactive techniques are limited, as they do not replace the doomed transaction by another or, when they do, they rely on the operating system for that, having little or no control on which transaction to run. This article proposes LUTS, a Lightweight User-Level Transaction Scheduler. Unlike other techniques, LUTS provides the means for selecting another transaction to run in parallel, thus improving system throughput. We discuss LUTS design and propose a dynamic conflict-avoidance heuristic built around its scheduling capabilities. Experimental results, conducted with the STAMP and STMBench7 benchmark suites, running on TinySTM and SwissTM, show how our conflict-avoidance heuristic can effectively improve STM performance on high contention applications / Doutorado / Ciência da Computação / Doutor em Ciência da Computação

Orientadores: Guido Costa Souza de Araújo, José Nelson Amaral / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-27T10:12:59Z (GMT). No. of bitstreams: 1 Pereira_MarcioMachado_D.pdf: 2922376 bytes, checksum: 9775914667eadf354d7e256fb2835859 (MD5) Previous issue date: 2015 / Resumo: Nos últimos anos, Memórias Transacionais (Transactional Memories ¿ TMs) têm-se mostrado um modelo de programação paralela que combina, de forma eficaz, a melhoria de desempenho com a facilidade de programação. Além disso, a recente introdução de extensões para suporte a TM por grandes fabricantes de microprocessadores, também parece endossá-la como um modelo de programação para aplicações paralelas. Uma das questões centrais na concepção de sistemas de TM em Software (STM) é identificar mecanismos ou heurísticas que possam minimizar a contenção decorrente dos conflitos entre transações. Apesar de já terem sido propostos vários mecanismos para reduzir a contenção, essas técnicas têm um alcance limitado, uma vez que o conflito é evitado por interrupção ou serialização da execução da transação, impactando consideravelmente o desempenho do programa. Este trabalho explora uma abordagem complementar para melhorar o desempenho de STM através da utilização de escalonadores. Um escalonador de TM é um componente de software que decide quando uma determinada transação deve ser executada ou não. Sua eficácia é muito sensível às métricas usadas para prever o comportamento das transações, especialmente em cenários de alta contenção. Este trabalho propõe um novo escalonador, Dynamic Transaction Scheduler ¿ DTS, para selecionar a próxima transação a ser executada. DTS é baseada em uma política de "recompensa pelo sucesso" e utiliza uma métrica que mede com melhor precisão o trabalho realizado por uma transação. Memórias Transacionais em Hardware (HTMs) são mecanismos interessante para implementar TM porque integram o suporte a transações no nível da arquitetura. Por outro lado, aplicações que usam HTM podem ter o seu desempenho dificultado pela falta de escalabilidade e transbordamento da cache de dados. Este trabalho apresenta um extenso estudo de desempenho de aplicações que usam HTM na arquitetura Haswell da Intel. Ele avalia os pontos fortes e fracos desta nova arquitetura, realizando uma exploração das várias características das aplicações de TM. Este estudo detalhado revela as restrições impostas pela nova arquitetura e introduz uma política de serialização simples, porém eficaz, para garantir o progresso das transações, além de proporcionar melhor desempenho / Abstract: In the last few years, Transactional Memories (TMs) have been shown to be a parallel programming model that can effectively combine performance improvement with ease of programming. Moreover, the recent introduction of (H)TM-based ISA extensions, by major microprocessor manufacturers, also seems to endorse TM as a programming model for today¿s parallel applications. One of the central issues in designing Software TM (STM) systems is to identify mechanisms or heuristics that can minimize contention arising from conflicting transactions. Although a number of mechanisms have been proposed to tackle contention, such techniques have a limited scope, because conflict is avoided by either interrupting or serializing transaction execution, thus considerably impacting performance. This work explores a complementary approach to boost the performance of STM through the use of schedulers. A TM scheduler is a software component that decides when a particular transaction should be executed. Their effectiveness is very sensitive to the accuracy of the metrics used to predict transaction behaviour, particularly in high-contention scenarios. This work proposes a new Dynamic Transaction Scheduler ¿ DTS to select a transaction to execute next, based on a new policy that rewards success and an improved metric that measures the amount of effective work performed by a transaction. Hardware TMs (HTM) are an interesting mechanism to implement TM as they integrate the support for transactions at the lowest, most efficient, architectural level. On the other hand, for some applications, HTMs can have their performance hindered by the lack of scalability and by limitations in cache store capacity. This work presents an extensive performance study of the implementation of HTM in the Haswell generation of Intel x86 core processors. It evaluates the strengths and weaknesses of this new architecture by exploring several dimensions in the space of TM application characteristics. This detailed performance study provides insights on the constraints imposed by the Intel¿s Transaction Synchronization Extension (Intel¿s TSX) and introduces a simple, but efficient, serialization policy for guaranteeing forward progress on top of the best-effort Intel¿s HTM which was critical to achieving performance / Doutorado / Ciência da Computação / Doutor em Ciência da Computação

How can a character from a children’s book become so divisive that he causes arguments amongst adults? This essay uses transactional reader response theory to explain the reason why the character Severus Snape from the Harry Potter book series by J.K. Rowling is so controversial. Applying notions from reader response theorists such as Rosenblatt and Iser together with earlier research on Snape will show how the reader’s opinion is affected by both the text itself and their own personal experience. A poll was created and posted on Facebook with over a thousand replies. This data is analysed and used to apply the theory on real examples. The conclusion of the essay is that Snape is both good and bad. He acts heroically but is also vindictive and petty. Snape is perhaps the most human of all Rowling’s characters and each reader recognises a little of themselves in him that they can relate to. Because of ongoing arguments regarding Snape readers have to constantly defend their opinion. As the opinion is re-evaluated it is also strengthened each time readers reconsider the story of Snape and, like Snape himself once asked Professor Quirrell to do, decide where their loyalties lie.

When integrating sustainability, companies are often overlooking the changes needed in their organisational culture. This hinders organisations’ core business to efficiently embed sustainability and dooms corporate sustainability initiatives to be superficial. A possible solution is for organisations to develop a sustainability- oriented organisational culture that engages employees with the sustainability change and that develops a leadership supportive of the engagement of their employees. As a result, this thesis aims at exploring how organisations can change their organisational culture in order to fully integrate sustainability by engaging employees and managers. Specifically, it studies how employee engagement can contribute to transforming organizational cultures to fully embed sustainability. Additionally, this paper analyses how managers can support employee engagement with sustainability. The thesis conducts a literature review to set the theoretical foundations; it further resorts to semi-structured interviews and document analysis conducted in a Swedish public company, which has begun to integrate sustainability into its culture. The study finds that organisations’ cultures are being changed at the artifact levels and, partially, at the values and beliefs level of their cultures. Additionally, the thesis establishes that organisations are failing to create the conditions for employee engagement. It finally shows that leadership in companies is not efficiently supporting the engagement of employees to integrate sustainability into their culture.