The safety of nuclear power plants must be proved, certified and improved. Probabilistic safety assessments are used to estimate the core meltdown risk, by means of sequential analyses of accidents. In order to assess probabilities of the appearance of these sequences, it is necessary to specifically assess probabilities of operation failures accomplished by human operators in a degraded mode. For this purpose, EDF, the French producer of electricity, developed a method that models failures of human actions, by means of a systematic determination of scenarios corresponding to different failure modes. This method, called MERMOS, has been used for several probabilistic safety assessments. In order to increase its reproducibility and to make it more robust, example missions and scenarios will be built. This set of example analyses will be used by experts assessing human reliability: they will develop studies and deduce results more easily. The purpose of this study involves the creation of a methodology to model existing analyses and human reliability data used in MERMOS. This study consists of optimizing a second generation human reliability assessment method in order to overpass its current weaknesses in an operational context by means of the identification of a set of example analyses. / Master of Science

Ce travail de thèse interroge la notion d'ancrage territorial dans la mise en œuvre des pratiques de Responsabilité Sociétale d'Entreprise (RSE) en faveur du développement économique territorial. Il relève d'une observation participante adossée au programme Une rivière, un territoire DEVELOPPEMENT initié par l'entreprise EDF au sein du bassin versant de la haute vallée de la Dordogne. D'abord, nous conduisons une étude relative aux fondements théoriques et aux contextes socio-économiques dans lesquels s'inscrivent les processus de co-construction des programmes de RSE territorialisée. Notre premier objectif est de mesurer les attentes des parties prenantes dans l'élaboration de ces programmes afin de comprendre comment ces attentes se matérialisent dans les réponses apportées par les entreprises. Ensuite, nous menons trois expérimentations en développant des formes d'ingénierie territoriale spécifiques. Notre deuxième objectif vise à mesurer la contribution effective du programme d'EDF à l'action publique territoriale, à identifier ses limites ainsi que les nouvelles attentes des acteurs. Enfin, nous confrontons nos résultats au programme cadre initié par EDF en réinterrogeant les concepts de RSE et d'ancrage territorial. Notre troisième objectif est de formuler d'éventuelles évolutions des programmes de RSE territorialisée. Les résultats font apparaître que ces programmes s'inscrivent dans des contextes socio-économiques particuliers. Les expérimentations menées mettent en évidence une contribution effective du programme d'EDF au développement territorial autour de formes d'accompagnement spécifiques favorisant l'émergence de projets qui s'inscrivent dans la gouvernance territoriale. De nouvelles attentes apparaissent autour d'un renforcement de l'interdépendance entre l'entreprise et le territoire, c'est pourquoi, nous proposons une évolution de ces programmes en adjoignant au cadre de référence une approche par la valeur partagée et partenariale destinée à favoriser cette interdépendance. / This thesis work investigates the notion of territorial anchoring throught the implementation of Corporate Social Responsibility (CSR) favouring territorial economic development. This work involves field research through the programme “a river, a territory – DEVELOPMENT” initiated by the EDF corporation within the catchment area of the high Dordogne valley. First we conduct a study of the theoretical foundations and socio-economical contexts in which the territorialised CSR co-construction programme processes are involved. Our first objective is to measure stakeholder expectation during the elaboration of these programmes to understand how these expectations materialise into responses given by corporations. Then, we set up three experiments through the development of specific territorial engineering approaches. Our second objective consists in measuring the effective contribution of the EDF programme for territorial public action, identify its limits and new expectations of its actors. Finally, we compared our results against the programme roadmap initiated by EDF by revisiting the CSR and territorial anchoring concepts. Our third objective is to formulate potential evolutions of territorialised CSR programmes. The results show that these programmes are embedded within particular socio-economic contexts. The conducted experimentations show an effective contribution of the EDF territorial development programme around specific support approaches favouring project emergence within territorial governance. Finally, new expectations appear around a reinforcement of the interdependency between corporations and territories. We then propose an evolution of these programmes by joining roadmaps with an approach based on shared and partnership values aimed at favouring this interdependency.

La ricerca mostra come la pratica delle regole contribuisca alla maturazione infantile, riconoscendo nell'ambito ludico-motorio una felice opportunità educativa. Il concetto di regola è stato affrontato nel suo orizzonte morale, anche attraverso l'accostamento ai più importati pensatori del mondo antico e moderno. Si è inoltre analizzato il modo in cui il riconoscimento della regola si sviluppa nel bambino durante la scuola primaria e come il gioco e lo sport possano contribuire alla crescita della persona. L’esperienza del laboratorio ludico-sportivo in contesti di vulnerabilità ( riferita al Progetto “L’Università Cattolica per i minori dell’Abruzzo” ) ha testimoniato come attraverso percorsi educativi mirati si possa contribuire alla maturazione del concetto di regola nel bambino. / The research shows how practice of rules contributes to child growth, admitting the sphere of game and movement as a lucky educational opportunity. The concept of rule has been faced in its moral aspect, also approaching the most important thinkers of ancient and modern world.Besides, the way the recognition of rule develops in the child during primary school has been analysed, and how game and sport can contribute to the growth of the person.The experience of “game and sport laboratory in vulnerable contexts” (regarding the project “Catholic University for children of Abruzzo”) has given evidence of how it is possible to contribute to the growth of the concept of rule in children through specific educational programme.

Advanced embedded systems can consist of many sensors, actuators and processors that are deployed on one or several boards, while having a demand of interacting with each other and sharing resources. Communication between different components usually has strict timing constraints. There is thus a strong need to provide solutions for time critical communication. This thesis focuses on both the support of real-time services over standard switched Ethernet networks and the improvement of systems' real-time characteristics, such as reducing delay and jitter in processors and on communication links. Switched Ethernet has been chosen in this work because of its major advantages in industry; it supports higher bit-rates than most other current LAN (Local Area Network) technologies, including field buses, still at a low cost. We propose using a star network topology with a single Ethernet switch. Each node is connected to a separate port of the switch via a full-duplex link, thereby eliminating collisions. A solid real-time communication protocol for switched Ethernet networks is proposed in the thesis, including a real-time layer between the Ethernet layer and the TCP/IP suite. The network has the capability of supporting both real-time and non real-time traffic and assuring adaptation to the surrounding protocol standards. Most embedded systems work in a dynamic environment, where the precise behavior of the network traffic can usually not be predicted. To support real-time services, we have chosen the Earliest Deadline scheduling algorithm (EDF) because of its optimality, high efficiency and suitability for being used in adaptive schemes. To be able to increase the amount of guaranteed real-time traffic, the notion of Asymmetric Deadline Partitioning Scheme (ADPS) is introduced. ADPS allows distribution of the end-to-end deadline of a message, sent from any source node in the network to any destination node via the switch, into two sub-deadlines, one for each hop according to the load of the physical link that it must traverse. For the EDF scheduling algorithm, the feasibility test is one of the most important techniques that provides us with information about whether or not the real-time traffic can be guaranteed by the network. With the same computational complexity as the feasibility test, a method has been developed to compute the minimum EDF-feasible deadline for a real-time task. The importance of this method in real-time applications lies in that it can be effectively used to reduce the response times of specific control activities or limit their input-output jitter. To allow more flexibility in the control of delay and jitter in real-time systems, a general approach for reducing task deadlines according to the requirements of individual tasks has been developed. The method allows the user to specify a deadline reduction factor for each task in order to better exploit the available slack according to the tasks' actual requirements. / <p>Ingår även i serien: Technical report. D / Department of Computer Science and Engineering, Chalmers University of Technology, 1653-1787 ; 28</p>

The theoretical tool of choice for the microscopic description of all medium- and heavy-mass nuclei is the Energy Density Functional (EDF) method. Such a method relies on the concept of spontaneous symmetry breaking and restoration. In that sense, it is intrinsically a two-step approach. However, the symmetry restoration procedure is only well-defined in the particular case where the energy functional derives from a pseudo-potential. Thereby and as it has been recently shown, existing parameterizations of the energy functional provides unphysical results. Such a problem as well as the lack of predictive power call for developing new families of functionals. The first part of the present work is devoted to a study of the symmetry restoration problem and to the identification of properties that could constrain the analytic form of energy functionals that do not derive from a pseudo-potential. The second part deals with the construction of an energy functional that derives from a pseudo potential. The difficulties of such work are (i) the identification of the minimal complexity of the pseudo-potential necessary to obtain an energy functional that is flexible enough to provide high-quality EDF parameterizations, (ii) the tedious analytical derivation of the functional and of the associated one-body fields, (iii) the implementation of the latter in existing codes, and (iv) the development of an efficient fitting procedure. Eventually, it seems possible to generate a parameterization that strictly derives from a pseudo-potential and that provides as good results as state-of-the-art (quasi) bilinear functionals.

<p>In this thesis work I have been working with two traffic simulators called Hank and ST Software. Hank is a research tool at the University of Iowa and ST Software is a commercial product. To evaluate which of these is the most suitable for behavior research I have implemented three types of intelligent agents: Overtaking Agent, Traffic Light Agent and Meeting Agent. The thesis work was extended by adding the possibility for realistic human behavior to the agents.</p><p>The result indicated that Hank allowed for greater control over behavior while ST Software allowed for faster and easier implementation.</p>

The requirements for real-time systems in safety-critical applications typically contain strict timing constraints. The design of such a system must be subject to extensive validation to guarantee that critical timing constraints will never be violated while the system operates. A mathematically rigorous technique to do so is to perform a schedulability analysis for formally verifying models of the computational workload. Different workload models allow to describe task activations at different levels of expressiveness, ranging from traditional periodic models to sophisticated graph-based ones. An inherent conflict arises between the expressiveness and analysis efficiency of task models. The more expressive a task model is, the more accurately it can describe a system design, reducing over-approximations and thus minimizing wasteful over-provisioning of system resources. However, more expressiveness implies higher computational complexity of corresponding analysis methods. Consequently, an ideal model provides the highest possible expressiveness for which efficient exact analysis methods exist. This thesis investigates the trade-off between expressiveness and analysis efficiency. A new digraph-based task model is introduced, which generalizes all previously proposed models that can be analyzed in pseudo-polynomial time without using any analysis-specific over-approximations. We develop methods allowing to efficiently analyze variants of the model despite their strictly increased expressiveness. A key contribution is the notion of path abstraction which enables efficient graph traversal algorithms. We demonstrate tractability borderlines for different classes of schedulers, namely static priority and earliest-deadline first schedulers, by establishing hardness results. These hardness proofs provide insights about the inherent complexity of developing efficient analysis methods and indicate fundamental difficulties of the considered schedulability problems. Finally, we develop a novel abstraction refinement scheme to cope with combinatorial explosion and apply it to schedulability and response-time analysis problems. All methods presented in this thesis are extensively evaluated, demonstrating practical applicability.

In this thesis work I have been working with two traffic simulators called Hank and ST Software. Hank is a research tool at the University of Iowa and ST Software is a commercial product. To evaluate which of these is the most suitable for behavior research I have implemented three types of intelligent agents: Overtaking Agent, Traffic Light Agent and Meeting Agent. The thesis work was extended by adding the possibility for realistic human behavior to the agents. The result indicated that Hank allowed for greater control over behavior while ST Software allowed for faster and easier implementation.

Hard real-time systems in robotics, space and military missions, and control devices are specified with stringent and critical time constraints. On the other hand, soft real-time applications arising from multimedia, telecommunications, Internet web services, and games are specified with more lenient constraints. Real-time systems can also be distinguished in terms of their implementation into preemptive and non-preemptive systems. In preemptive systems, tasks are often preempted by higher priority tasks. Non-preemptive systems are gaining interest for implementing soft-real applications on multithreaded platforms. In this dissertation, I propose a new algorithm that uses a two-level scheduling strategy for scheduling non-preemptive soft real-time tasks. Our goal is to improve the success ratios of the well-known earliest deadline first (EDF) approach when the load on the system is very high and to improve the overall performance in both underloaded and overloaded conditions. Our approach, known as group-EDF (gEDF), is based on dynamic grouping of tasks with deadlines that are very close to each other, and using a shortest job first (SJF) technique to schedule tasks within the group. I believe that grouping tasks dynamically with similar deadlines and utilizing secondary criteria, such as minimizing the total execution time can lead to new and more efficient real-time scheduling algorithms. I present results comparing gEDF with other real-time algorithms including, EDF, best-effort, and guarantee scheme, by using randomly generated tasks with varying execution times, release times, deadlines and tolerances to missing deadlines, under varying workloads. Furthermore, I implemented the gEDF algorithm in the Linux kernel and evaluated gEDF for scheduling real applications.

In previous works, we have shown two-car households to be better suited than one-car households for leveraging the potential benefits of the battery electric vehicle (BEV), both when the BEV simply replaces the second car and when it is used optimally in combination with a conventional car to overcome the BEV’s range limitation and increase its utilization. Based on a set of GPS-measured car movement data from 64 two-car households in Sweden, we here assess the potential electric driving of a plug-in hybrid electric vehicle (PHEV) in a two-car household and compare the resulting economic viability and potential fuel substitution to that of a BEV. Using estimates of near-term mass production costs, our results suggest that, for Swedish two-car households, the PHEV in general should have a higher total cost of ownership than the BEV, provided the use of the BEV is optimized. However, the PHEV will increasingly be favored if, for example, drivers cannot or do not want to optimize usage. In addition, the PHEV and the BEV are not perfect substitutes. The PHEV may be favored if drivers require that the vehicle be able to satisfy all driving needs (i.e., if drivers don’t accept the range and charge-time restrictions of the BEV) or if drivers requires an even larger battery in the BEV to counter range anxiety. We find that, given a particular usage strategy, the electric drive fraction (EDF) of the vehicle fleet is less dependent on whether PHEVs or BEVs are used to replace one of the conventional cars in two-car households. Instead, the EDF depends more on the usage strategy, i.e., on whether the PHEV/BEV is used to replace the conventional car with the higher annual mileage (“the first car”), the less used car (“the second car”), or is used flexibly to substitute for either in order to optimize use. For example, from a fuel replacement perspective it is often better to replace the first car with a PHEV than to replace the second with a BEV.