Comportement humain | EPFL Graph Search

vignette| Les Homo Sapiens (humains) affichent souvent différents types de comportement. Le comportement humain est la capacité potentielle et exprimée (mentalement, physiquement et socialement) d'individus ou de groupes humains à répondre à des stimuli internes et externes tout au long de leur vie. Alors que les traits spécifiques de la personnalité, du tempérament et de la génétique peuvent rester stables, d'autres comportements changent à mesure que l'on passe entre les étapes de la vie, c'est-à-dire de la naissance à l'adolescence, à l'âge adulte et, par exemple, à la parentalité et à la retraite. Le comportement est également conduit, en partie, par des pensées et des sentiments, qui donnent un aperçu de la psyché, révélant des choses telles que les attitudes et les valeurs. Le comportement humain est façonné par des traits psychologiques, car les types de personnalité varient d'une personne à l'autre, produisant des actions et des comportements différents. Les personnes extrave

District scale influence of waste heat on the subsurface conditions: a numerical investigation for Chicago

Stéphane Hartmann

Since the 20th century, the rate of urbanization in the world has been increasing exponentially and will reach 68% in 2050. In parallel with this expansion, the size and activities of cities are also greatly growing. As a result, cities are depleting available space and energy resources at an alarming rate. In order to be able to respond to these demands, the solution of building more underground structures is being put in place and is already being implemented in some megacities. These infrastructures have demonstrated that human activity is the factor that generates the main heat flow in the underground and that it has a significant impact on the temperature of urban aquifers. Through the use of geothermal energy, the increase in temperature of the subsoil can be ecologically and economically beneficial. However, for the evaluation of the geothermal potential, many factors have to be taken into consideration (geology, human activities, urban planning, etc), making its execution complex. As a result, most of the research already undertaken on this subject proves to be sketchy and incomplete. This work thus proposes a complete study of the influence of the different heat sources on the subsoil. For this purpose, a unique FE THM (Thermo-hydro-mechanical) model simulating the heat losses from underground structures into the ground over a 50-year period has been developed for the Loop District in Chicago (USA). It can also be adapted to any other region for which geological and underground structural data are available. The case study is challenging due to its relevance and location. Indeed, the Loop remains the second largest commercial district in the United States after Midtown Manhattan and statistics show that it consumes one third of Chicago’s annual energy. By this means, the importance and necessity of addressing this topical issue is shown. This study analyses the impact of heat sources on the thermal, mechanical and hydraulic properties of the subsurface while demonstrating a latency time observed between thermal and mechanical effects. The hydraulic investigations carried out have demonstrated the constancy as well as the very low impact of the groundwater flow over the time in Chicago. A detailed study on the interaction of the different heat sources showed that the combined effect of the different heat sources present (basement, subway and ambient air) is the sum of the effects of each of them separately. Finally, it demonstrated that the contribution of the heat sources to the thermal and mechanical variations always undergoes the same process over time and the same final distribution: 70% for the basements, 30% for the underground subway lines and >1% for the ambient air.

2020

Uncooperative Rendezvous in Space: Design of an Electronic Architecture for High Performance Avionic with Multi Sensor Input and Intensive Data Rate.

Michaël Yannick Juillard

Active Debris Removal missions consist of sending a satellite in space and removing one or more debris from their current orbit. A key challenge is to obtain information about the uncooperative target. By gathering the velocity, position, and rotation of the desired object, the satellite is able to plan its trajectory and define the sequence of approach. It requires the use of a variety of sensors with often a high data rate. For this task, a dedicated payload computer is envisioned with the responsibility of processing the information from the various rendezvous sensors. This component has the goal to provide meaningful information to the main satellite computer about the targeted debris. The focus of this work is on the data processing, the number of elements, and the electrical energy with constraints due to internal communication.First, an avionic testbench was built at the EPFL Space Center to assess early hardware and software architectures. The goal is to enable Hardware-In-the-Loop testing while developing the payload computer. A communication data bus has been implemented between the Platform and the Payload On-Board Computer. Emphasis was placed on the reliability of the high-level protocol and multiple concepts for improvement were analyzed.In a second phase, the testbench has been extended to support other data buses. The aim was to develop a reliable and efficient backup or fall-back data bus in case of failure in the main link. Four data buses have been tested with extensive analyses on their resilience to error and the efficiency of their data exchange.In parallel, extensive work has been performed to develop a simulation and optimization tool. Its goal is to support the design of payload avionic architectures for ADR missions by providing trade-offs and analyses. In the first iteration, a simulator has been created with instances of various high-level elements modeled.The second iteration introduced the additional dimension of optimization. It is trying to determine the best set of instruments and algorithms to use. With this capability, numerous analyses have been conducted on the influence of various parameters linked to the general optimizer behavior. It allows us to better understand the strength and limitations of the tool.The third step regarding the tool was to start its verification. The task has been to develop an Hardware-In-the-Loop architecture to compare its behavior with the results of the optimizer. The implementation of various mock-up algorithms enables the verification of their models in the tool. These analyses guarantee the feasibility of the outputted solution.The last part was dedicated to the creation and analysis of a realistic payload avionic architecture. The goal was to test the capability of the tool with hardware elements inspired by actual components. This work has shown the procedure to efficiently use the tool in the design phase of a mission.In conclusion, the work on the communication between the Payload and the Platform On-Board Computer has brought valuable lessons and experiences to the projects. They can now be used for the establishment of the high-level protocol into ClearSpace-1 flight software. In addition, the optimizer created allows tackling the design of complex payload avionic architecture where mass saving and processing resources are crucial. It is an essential point to develop a highly efficient payload computer for an Active Debris Removal satellite.

EPFL2022