Human behavior | EPFL Graph Search

Human behavior is the potential and expressed capacity (mentally, physically, and socially) of human individuals or groups to respond to internal and external stimuli throughout their life. Behavior is driven by genetic and environmental factors that affect an individual. Behavior is also driven, in part, by thoughts and feelings, which provide insight into individual psyche, revealing such things as attitudes and values. Human behavior is shaped by psychological traits, as personality types vary from person to person, producing different actions and behavior. Social behavior accounts for actions directed at others. It is concerned with the considerable influence of social interaction and culture, as well as ethics, interpersonal relationships, politics, and conflict. Some behaviors are common while others are unusual. The acceptability of behavior depends upon social norms and is regulated by various means of social control. Social norms also condition behavior, whereby humans are

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

Exploiting environmental signals to enable policy correlation in large-scale decentralized systems

Panayiotis Danassis, Zeki Doruk Erden, Boi Faltings

Can artificial agents benefit from human conventions? Human societies manage to successfully self-organize and resolve the tragedy of the commons in common-pool resources, in spite of the bleak prediction of non-cooperative game theory. On top of that, real-world problems are inherently large-scale and of low observability. One key concept that facilitates human coordination in such settings is the use of conventions. Inspired by human behavior, we investigate the learning dynamics and emergence of temporal conventions, focusing on common-pool resources. Extra emphasis was given in designing a realistic evaluation setting: (a) environment dynamics are modeled on real-world fisheries, (b) we assume decentralized learning, where agents can observe only their own history, and (c) we run large-scale simulations (up to 64 agents). Uncoupled policies and low observability make cooperation hard to achieve; as the number of agents grow, the probability of taking a correct gradient direction decreases exponentially. By introducing an arbitrary common signal (e.g., date, time, or any periodic set of numbers) as a means to couple the learning process, we show that temporal conventions can emerge and agents reach sustainable harvesting strategies. The introduction of the signal consistently improves the social welfare (by 258% on average, up to 3306%), the range of environmental parameters where sustainability can be achieved (by 46% on average, up to 300%), and the convergence speed in low abundance settings (by 13% on average, up to 53%).

SPRINGER2022

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