Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 127-140) Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 127-140) Also available online.

abstract: Research on the psychology of social power has shown how experiences of power tend to promote goal-oriented behavior and sexual perception in individuals. These experiences need not be generated through real-life power dynamics, but can be primed experimentally in the lab. A recent study has explored how power affects even lower level goal-oriented motor movement, showing how increased power facilitates the initiation of goal-oriented motor actions (Maner et al., 2010). However, this research did not explore how these goal-oriented motor movements promoted by power dynamically evolve over time, or can be influenced by sexual perceptual processes. Using an experimental paradigm known as computer mouse-tracking, we designed an experimental task to asses how participants’ – primed with either a High or Low sense of power – motor movements and sexual perceptual processes co-evolved and influenced one another during decision-making. We analyzed four distinct mouse-tracking variables, including traditional reaction time measures and novel measures indexing real-time decision-making processes. Several hypotheses are proposed and discussed. No significant findings emerged, however general trends showed promising signs for future iterations of the study. The study limitations and proposed future directions for studying these phenomena are discussed. / Dissertation/Thesis / Masters Thesis Psychology 2016

Orientador: José Maria Campos dos Santos / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-19T06:05:00Z (GMT). No. of bitstreams: 1 Sica_MauricioRoselli_M.pdf: 6187406 bytes, checksum: eb76c3ee4e60cfc7e2fbff17dbb0b05b (MD5) Previous issue date: 2011 / Resumo: As simulações físicas em laboratórios da indústria automotiva são realizadas utilizando informações colhidas de veículos que são submetidos a ciclos de testes em rotas urbanas. Medir as respostas em pontos específicos durante uma rota de teste, não significa conhecer as excitações a que o veículo esta sendo submetido, visto que este normalmente é composto por sistemas mecânicos não lineares. O objetivo deste trabalho é desenvolver um algoritmo que possibilite através dos dados de resposta medidos em campo, conhecer as excitações de entrada, contribuindo para a reprodução da rota de teste. A metodologia utilizada está baseada na obtenção de funções de resposta em freqüência, de modelos lineares simples e no desenvolvimento de sinais de entrada, capazes de reproduzir as mesmas respostas medidas nas rotas nos sistemas não lineares. O algoritmo desenvolvido foi avaliado com simulações em sistemas lineares e não lineares de um, dois e quatro graus de liberdade. Através dos sinais de resposta medidos em um sistema e, utilizando sinal de identificação tipo Schroeder, foi possível estimar as forças de excitação, com um erro menor do que 1,0% para sistemas de dois graus de liberdade lineares e não lineares. No caso de sistemas com quatro graus de liberdade este valor foi menor do que 1,5%, utilizando sinais de identificação do tipo multisseno. Discute-se a metodologia utilizada para a obtenção das funções de resposta em freqüência comparando-a com outras empregadas em equipamentos comerciais, bem como a influência de fatores no processo de convergência do algoritmo, como o grau de não linearidade, a qualidade do sinal medido e a importância da escolha do sinal para a identificação dos sistemas / Abstract: Laboratory simulation testing in the automotive industry is carried out considering information acquired from vehicle urban routes testing. Due to the non-linearity of the vehicle mechanical systems, the output measuring collected from routes on specific points, does not mean the knowledge of the input signal excitation which it is submitted. The present study focuses on the development of an iterative algorithm that knowing the output signals measured, it is able to search for the input excitations, so given subsidies to reproduce events of the urban route, with its load amplitude and its frequencies. The methodology is based on the frequency response function of simple linear models and on the development of input signal, which is capable to reproduce the same measured responses of non-linear system. The developed algorithm was validated with simulations on linear and non linear system with one, two and four degrees of freedom. Making use of the Schroeder identification signal, it was possible to estimate input forces with an error lower than 1,0%, for linear and non-linear systems with two degrees of freedom. In the case of four degrees of freedom the algorithm converges to estimate input force with a tolerance of error lower than 1,5%, using multissine identification signal. A discussion about the methodology used to obtain the frequency function response is carried out, comparing it with others found in commercial test equipments, as well the influence of some factors on the algorithm process of convergence, as the level of the non-linearity of the system, the quality of the acquisition of signal response and the importance of the correct choice of the input signal for the system identification / Mestrado / Dinâmica / Mestre em Engenharia Automobilistica

No description available.

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

The aim of this study is to investigate means of efficiently assessing the effects of distributed structural modification on the dynamic properties of a complex structure. The helicopter structure is normally designed to avoid resonance at the main rotor rotational frequency. However, very often military helicopters have to be modified (such as to carry a different weapon system or an additional fuel tank) to fulfill operational requirements. Any modification to a helicopter structure has the potential of changing its resonance frequencies and mode shapes. The dynamic properties of the modified structure can be determined by experimental testing or numerical simulation, both of which are complex, expensive and time-consuming. Assuming that the original dynamic characteristics are already established and that the modification is a relatively simple attachment such as beam or plate modification, the modified dynamic properties may be determined numerically without solving the equations of motion of the full-modified structure. The frequency response functions (FRFs) of the modified structure can be computed by coupling the original FRFs and a delta dynamic stiffness matrix for the modification introduced. The validity of this approach is investigated by applying it to several cases, 1) 1D structure with structural modification but no change in the number of degree of freedom (DOFs). A simply supported beam with double thickness in the middle section is treated as an example for this case; 2) 1D structure with additional DOFs. A cantilever beam to which a smaller beam is attached is treated as an example for this case, 3) 2D structure with a reduction in DOFs. A four-edge-clamped plate with a cut-out in the centre is treated as an example for this case; and 4) 3D structure with additional DOFs. A box frame with a plate attached to it as structural modification with additional DOFs and combination of different structures. The original FRFs were obtained numerically and experimentally except for the first case. The delta dynamic stiffness matrix was determined numerically by modelling the part of the modified structure including the modifying structure and part of the original structure at the same location. The FRFs of the modified structure were then computed. Good agreement is obtained by comparing the results to the FRFs of the modified structure determined experimentally as well as by numerical modelling of the complete modified structure.

Deux situations de comportement égoïste des agents dans les réseaux de communication sont considérées dans le cadre de la théorie des jeux.La première situation concerne les réseaux de communication utilisant un routage décentralisé basé sur des agents autonomes. Nous étudions les propriétés de convergence des dynamiques de meilleures réponses dans un jeu de routage sur des liens parallèles. Le jeu implique un nombre fini d'agents, chacun décidant comment son trafic est routé sur les liens de manière à minimiser son propre coût. Nous proposons l'utilisation du rayon spectral généralisé des matrices Jacobiennes de l'opérateur de meilleure réponse pour démontrer la convergence.La seconde situation apparaît dans les réseaux tolérants aux délais dont l'objectif est de permettre la communication dans des environnements où la connectivité n'est qu'intermittente et où les délais de communication peuvent être très longs. Nous proposons tout d'abord un mécanisme d'incitation basé sur une récompense pour convaincre les noeuds mobiles de relayer les messages, et analysons l'influence de l'information donnée par la source (nombre de copies du message, âge de ces copies) aux relais sur le prix à payer pour transmettre le message. Nous considérons ensuite un modèle dans lequel la source propose une récompense fixe. Les noeuds mobiles peuvent alors décider d'accepter ou non le message, et s'ils l'acceptent, peuvent ensuite à tout moment décider de l'abandonner. Nous modélisons l'interaction entre les noeuds mobiles sous la forme d'un jeu stochastique partiellement observable et analysons les politiques optimales pour les relais. / This thesis focuses on the issues related to the selfish behavior of the agents in the communication networks. We are particularly interested in two situations in which these issues arise and we address game-theoretical framework to study them.The first situation relates to communication networks using a distributed routing based on autonomous agents. Compared to a centralized routing, this type of routing offers significant advantages in terms of scalability, ease of deployment or robustness to failures and environmental disturbances. We investigate the convergence properties of the sequential best-response dynamics in a routing game over parallel links. The game involves a finite number of routing agents each of which decides how much flow to route on each of the links with the objective of minimizing its own costs. For some particular cases (e.g., two players), the convergence of the best-response dynamics can be proved by showing that this game has a potential function. For other cases, a potential function has remained elusive. We propose the use of non-linear spectral radius of the Jacobian of the best-response dynamics as an alternative approach to proving its convergence.The second situation occurs in Delay Tolerant Networks (DTNs) that have been the subject of intensive research over the past decade. DTN has an idea to support communication in environments where connectivity is intermittent and where communication delays can be very long. We focus on game-theoretic models for DTNs. First, we propose an incentive mechanism to persuade selfish mobile nodes to participate in relaying messages, and investigate the influence of the information given by the source (number of existing copies of the message, age of these copies) to the relays on the rewards proposed. For static information polices, that is the same type of information given to all the relays, it is shown that the expected reward paid by the source is independent of the policy. However, the source can reduce the reward by dynamically adapting the type of information based on the meeting times with the relays. For the particular cases, we give some structural results of the optimal adaptive policy. Next, we consider the model where the source proposes a fixed reward. The mobile relays can decide to accept or not the packet and then to drop the packet in the future. This game can be modelled as a partially-observable stochastic game. For two relays, we have shown that the optimal policies for the relays relates to the threshold type.

Pourquoi faire un effort pour la communauté sans rien recevoir en retour? C’est habituellement par conviction ou pour répondre à une norme sociale. En s’intéressant au problème du recyclage, nous définissons un modèle de comportement qui intègre ces deux facteurs. Nous déterminons sous quelles conditions un individu décide d’agir bénévolement, puis nous étudions comment ce comportement se propage dans la population. Cela nous permet de déduire comment un gouvernement doit pondérer ses efforts entre la publicité et la consigne pour tendre vers un taux de recyclage parfait au coût minimal. Nous prouvons aussi que dans certaines circonstances, il est préférable de ne pas encourager la participation au bien public. En effet, à mesure que plus de gens y participent, des tensions sociales émergent entre ceux qui font un effort et ceux qui n’en font pas. Celles-ci peuvent être assez fortes pour contrebalancer les bénéfices attendus du bien public / The commons need not be a tragedy: impact of peer-pressure and opinions Why do people help the community without getting anything in return? Usually, they either hold the firm belief they should do so or they want to follow a social norm. The behavioural model of this paper takes those two factors into account and applies them to recycling issues. It shows under which condition people act selflessly and how this behaviour spreads across the population. This paper then determines how governments must balance advertising and packaging refunding in order to increase recycling rate at minimal cost. It also proves that under certain circumstances it is preferable not to start transition toward cooperation. Indeed, as people progressively start cooperating, the population becomes divided between followers and opponents to this new attitude. As long as this heterogeneity remains, peer-pressure causes a cost that may outweigh the expected benefits of cooperation.

Approved for public release, distribution is unlimited / In this thesis, the ocean was modeled as a waveguide with an ideal pressure - release surface, and an ideal rigid bottom. The ocean waveguide was then treated as a linear, time - invariant, space - variant (TISV) filter or communication channel. The filter is time - invariant because no motion was modeled and because the properties of the ocean were assumed to be constant. The filter is space - variant because of the presence of the two boundaries, that is, the ocean surface and ocean bottom. This thesis investigates the ocean as a linear TISV filter by evaluating 1) the complex frequency response, 2) the impulse response, and 3) the transfer function of the ocean with respect to depth. It is shown that the TISV impulse response of the ocean contains information that can be used to help localize a target in range and whether the target is above or below the receiver. Computer simulation results were obtained by evaluating the three filter functions for several different test cases. / Ensign, United States Navy