無論在電腦動畫、電玩或電影產業，利用電腦自動產生虛擬人群已逐漸成為不可或缺的要素之一。這些虛擬人群，往往是系統先賦與每個虛擬代理人(agent)基礎智能，然後藉由個體之間的互動法則所自動產生。然而，過去因為普遍未考量真實群體情境中的傳播與互動模式，使得虛擬人群所表現的群體行為與現實情況仍有些差距。因此，我們引用社會心理學文獻，建立一個具有溝通機制的人群模擬平台(IMCrowd)，以期自動產生與現實群眾動態更相似的模擬人群。IMCrowd是多代理人(Multi-agent)基礎的系統，其中每個虛擬代理人都具有區域的感知範圍與自主能力，因此他們能夠自動地與環境中的其它物件互動與反應。由於我們為IMCrowd所建立的溝通模型考量了社會心理學的理論，因此虛擬人群能浮現真實群體動態中的社會互動模式，如情緒傳染與從眾效應。本研究以IMCrowd執行了多種情境下群眾暴動與群眾控制的模擬，藉此展現本系統的應用將不僅可提升群體模擬的真實度，亦可做為社會心理學家研究群體行為的工具。 / Using computer to automatically generate simulated crowd has become a trend in animation, computer game, and film productions. Many of these works were produced by modeling the intelligence of the agents in a crowd and their interactions with other nearby agents and the environment. However, the perceived facts or elicited emotions usually do not propagate in the crowd as they should in the real life. In this work we attempt to build up a communication model to simulate a large variety of crowd behaviors including the course of crowd formation. The proposed crowd simulation system, IMCrowd, has been implemented with a multi-agent system in which each agent has a local perception and autonomous abilities to improvise their actions. The algorithms used in our communication model in IMCrowd are based heavily on sociology research. Therefore, the collective behaviors will emerge out of the social process such as emotion contagion and conformity effect among individual agents. Several elaborate riot simulations and riot control simulations are demonstrated and reported in this thesis as the application examples of IMCrowd. Thus, we claim that IMCrowd may not only benefit on enhancing realism of crowd animation but also be useful in studying crowd behaviors such as panic, gathering, and riots.

Submitted by Claudio Meilman Ferreira (claudio.meilman@gmail.com) on 2017-01-05T15:53:53Z No. of bitstreams: 1 Claudio_Ferreira - Dissertação_Final.pdf: 1435979 bytes, checksum: f28673c2b369335f45c63beb6e43c635 (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2017-01-06T13:51:55Z (GMT) No. of bitstreams: 1 Claudio_Ferreira - Dissertação_Final.pdf: 1435979 bytes, checksum: f28673c2b369335f45c63beb6e43c635 (MD5) / Made available in DSpace on 2017-01-17T12:18:01Z (GMT). No. of bitstreams: 1 Claudio_Ferreira - Dissertação_Final.pdf: 1435979 bytes, checksum: f28673c2b369335f45c63beb6e43c635 (MD5) Previous issue date: 2016-12-06 / The impact of economic incentives on healthier eating is unclear, particularly in the long-term (i.e., after the intervention period). This research assessed the short- and long-term effectiveness of a private nutrition company’s promotion initiative in school cafeterias in Belo Horizonte, Brazil. Two hundred and eight children and adolescents from 3 schools participated in a short-lived, lottery-based incentives program contingent on the purchase of locally promoted healthy products. One hundred and forty-four children and adolescents from a fourth comparable school served as controls. A multilevel model compared the average number of promoted healthy products purchased daily per participant before (26 weekdays), during (9 weekdays), and after (28 weekdays) the intervention period. The results indicate a clear short-term effect. The incentives program significantly increased the purchase of promoted healthy products during (vs. before) the intervention period in the treated schools, specially among girls and younger children. On average, no long-term effect was observed. The purchase of the promoted healthy products returned to pre-intervention levels immediately after the removal of the incentives program. Interestingly, a detailed analysis revealed a rather heterogeneous long-term effect based on past consumption behavior. The incentive promoted a positive long-term effect on the children who had never consumed the incentivized healthier products prior to the intervention, whereas a negative long-term effect was noted for the already habitual consumers of the targeted healthier products. Past consumption behavior must be taken into consideration for a complete understanding of the long-term effects of incentives on healthier eating. / O impacto de incentivos econômicos sobre a alimentação saudável não é claro, particularmente no longo prazo (ou seja, após o período da intervenção). Esta pesquisa avaliou a eficácia de curto e longo prazo de uma iniciativa de promoção de uma empresa de nutrição privada em cantinas escolares em Belo Horizonte, Brasil. Duzentas e oito crianças e adolescentes de três escolas participaram de um programa de incentivos de curta duração baseado em um sorteio, condicionado à compra de produtos saudáveis promovidos localmente. Cento e quarenta e quatro crianças e adolescentes de uma quarta escola comparável serviram como controles. Um modelo multinível comparou o número médio de produtos saudáveis promovidos adquiridos diariamente por participante antes (26 dias úteis), durante (9 dias úteis) e após (28 dias úteis) o período da intervenção. Os resultados indicam um efeito claro de curto prazo. O programa de incentivos aumentou significativamente a compra de produtos saudáveis promovidos durante o período da intervenção (vs. antes) nas escolas tratadas, especialmente entre as meninas e crianças mais novas. Em média, nenhum efeito de longo prazo foi observado. A compra dos produtos saudáveis promovidos retornou aos níveis pré-intervenção imediatamente após a remoção do programa de incentivos. Curiosamente, uma análise detalhada revelou um efeito bastante heterogêneo de longo prazo baseado no comportamento prévio de consumo dos indivíduos. O incentivo promoveu um efeito positivo de longo prazo sobre as crianças que nunca haviam consumido os produtos promovidos e saudáveis antes da intervenção, ao passo que um efeito negativo de longo prazo foi observado para os consumidores já habituais dos produtos mais saudáveis visados. O comportamento do consumo passado deve ser levado em consideração para uma melhor compreensão dos efeitos de longo prazo de incentivos sobre uma alimentação mais saudável.

This dissertation concerns the self-organization behaviors in different types of multi-agent systems, and possible ways to apply interventions on top ofthat to achieve certain goals. A bounded confidence opinion dynamics modelis considered for the first two papers. Theoretical analysis of the model isperformed and modifications of the model are given so that it will have better properties in some aspect. Leader-follower based models are studied in the third to fifth papers where various optimal control problems are considered. Different methods such as Pontryagin minimum principle and dynamic programming are used to solve those optimal control problem. For complex problems, one may only get approximate solutions or suboptimal solutions.In Paper A and Paper B, we consider the continuous-time Hegselmann-Krause (H-K) model and its variations and target the problem of reaching consensus. A sufficient condition on the initial opinion distribution is givento guarantee consensus for the original continuous-time H-K model. A modified model is provided and proven to be able to lead a larger range of initial opinions to synchronization. An H-K model with an exo-system is also studied where sufficient conditions on the exo-system are given for the purpose of consensus.In Paper C and Paper D, optimal control problems with leader-followerbased multi-agent systems are discussed. Analytic solutions are derived if the dynamics is linear by applying Pontryagin minimum principle. For generalnon-linear leader-follower interactions, we provide a method that use sstatistic moments of the follower crowd to approximate the optimal control.The dynamic programming approach is used and certain approximation ofthe Hamilton-Jacobi-Bellman equations is needed. The computational burdenis so heavy that model predictive control method is required in practical applications.In Paper E, we apply a similar method to the approach used in PaperD to target a pollutant elimination problem. It implies that we can use themethod to attack optimal control problem with partial differential equation constraints by discretization in space. The dimension of the discretization is not related to the computational complexity since only the statistic moments are needed. / <p>QC 20161201</p>

The ubiquity of digital media provides an unprecedented possibility to redefine the process and methods of design. Through experience from a series of creative projects, I investigate how certain aspects of the web allow for design to attain a degree of autonomy, thus producing results that go beyond anticipation and expertise of the author. Utilizing an unlimited capacity to store the content and retrieve immediate feedback, the designer’s role can be shifted to that of an initiator defining rules and boundaries, from which the process can evolve independently based on the input of users and data. The design output in such conditions is the development of schemes in which the author remains, but is marginalized as a producer – consciously restraining his level of control. Rather then struggling to add something singular to the bottomless pit of information, the designer is relegated in the role of medium: collecting and recombining the bits of fragmented data into the structures conveying meaning.

Nous étudions dans ce travail les mouvements de foule intervenant dans les situa- tions d’urgence. Nous proposons un modèle macroscopique (la foule est représentée par une densité de personnes) obéissant à deux principes très simples. Tout d’abord, chaque personne possède une vitesse souhaitée (typiquement celle qui la mène vers la sortie), qu’elle adopterait en l’absence des autres. Ensuite, la foule doit respecter une contrainte de congestion, et la densité de personnes doit rester inférieure à une valeur fixée. Cette contrainte impose une vitesse de déplacement différente de la vitesse souhaitée. Nous choisissons de prendre comme vitesse réelle celle qui est la plus proche, au sens des moindres carrés, de la vitesse souhaitée, parmi les champs de vitesses admissibles, au sens où ils respectent la contrainte de densité maximale. Le modèle obtenu s’écrit sous la forme d’une équation de transport impliquant une vitesse peu régulière a priori, et qui ne peut être étudiée par des méthodes classiques. Nous démontrons un résultat d’existence grâce à la théorie du transport optimal, tout d’abord dans le cas d’une vitesse donnée comme le gradient d’une fonction, puis dans le cas général. Nous mettons également en œuvre un schéma numérique de type catching-up : à chaque pas de temps, la densité est déplacée selon le champ de vitesse souhaitée, puis est projetée sur l’ensemble des densités admissibles. Les résultats obtenus fournissent des temps d’évacuation dont l’ordre de grandeur est proche de la réalité. / In this work, we aim at modelling crowd motion in emergency situations. We propose a macroscopic model (where people are represented as a density) following two basic principles. First, each individual has a spontaneous velocity (typically, the one which leads to the nearest exit) which would be fulfilled in the absence of other people. On the other hand, the crowd has to respect a congestion constraint, and its density must remain underneath a critical density. This constraint prevents people from following their desired velocity. The actual velocity we consider is the closest, in a mean square sense, to the desired one, among the velocities which respect the maximal density constraint.The mathematical formulation writes as a transport equation which cannot be studied with classical methods, since the real velocity field has no a priori regularity, even if the desired velocity is smooth. Thanks to the optimal transport theory, we prove an existence result, first in the case where the desired velocity is the gradient of a given function, and then in the general framework. We also propose a numerical scheme which follows the catching-up principle: at each time step, we move the density according to the spontaneous velocity, and then project it onto the space of admissible densities. The numerical results we obtain reproduce qualitatively the experimental observations

Un robot bipède doit pouvoir marcher en toute sécurité dans une foule. Pour cela, il faut prendre en compte deux aspects : l’équilibre et l'évitement des collisions. Maintenir l’équilibre implique d'éviter les défaillances dynamiques et cinématiques de la dynamique instable du robot. Pour ce qui est de l’évitement des collisions, il s’agit d’éviter le contact entre le robot et des individus. Nous voulons être capables de satisfaire ces deux contraintes simultanément, à l’instant présent mais aussi dans le futur. Nous pouvons assurer l’équilibre du robot indéfiniment en le faisant entrer dans un cycle limite de marche ou en le faisant s’arrêter après quelques pas. Néanmoins, une telle garantie pour l’évitement d’obstacle n’est pas possible pour plusieurs raisons : impossibilité de connaître de manière absolue la direction vers laquelle les individus se dirigent, limitations cinématiques et dynamiques du robot, mouvement adverse de la foule, etc. Nous traitons ces limitations avec une stratégie standard de navigation dans une foule, appelée passive safety, qui nous permet de formuler une loi de commande prédictive avec laquelle nous assurons l’équilibre et l'évitement des collisions, de manière unifiée, en faisant s’arrêter le robot de manière sécurisée et en temps fini. De plus, nous définissons une nouvelle stratégie de navigation sûre basée sur le principe d’évitement des collisions aussi longtemps que possible, qui a la propriété de minimiser leur apparition et sévérité. Nous proposons une formulation lexicographique qui synthétise des mouvements conformes à ce principe. Nous augmentons les degrés de liberté de la locomotion d’un robot bipède en permettant la variation de l’orientation et de la durée des pas en ligne. Cependant, cela introduit des non-linéarités dans les contraintes de nos problèmes d’optimisation. Nous faisons des approximations de ces contraintes non-linéaires avec des contraintes linéaires sûres de sorte que la satisfaction des secondes implique la satisfaction des premières. Nous proposons une nouvelle méthode de résolution des problèmes non-linéaires (Optimisation Quadratique Successive Sûre) qui assure la faisabilité des itérations de Newton en utilisant cette redéfinition des contraintes. Nous simulons la marche d’un robot bipède dans une foule pour évaluer la performance de nos lois des commandes. D’une part, nous réussissons à réduire (statistiquement) la quantité et la sévérité des collisions en comparaison avec la méthode de passive safety, spécialement dans les conditions d’incertitude de la marche du robot dans une foule. D’autre part, nous montrons des exemples de comportements typiques du robot, qui découlent de la liberté de choisir l’orientation et la durée des pas. Nous rapportons le coût de calcul de notre méthode de résolution des problèmes non-linéaires en comparaison avec une méthode standard. Nous montrons qu’une seule itération de Newton est nécessaire pour arriver à une solution faisable, mais que le coût de calcul dépend du nombre de factorisations de l’active set dont nous avons besoin pour arriver à l’active set optimal. / We want a biped robot to walk safely in a crowd. This involves two aspects: balance and collision avoidance. The first implies avoiding kinematic and dynamical failures of the unstable walking dynamics of the robot; the second refers to avoiding collisions with people. We want to be able to solve both problems not only now but also in the future. We can ensure balance indefinitely by entering in a cyclic walk or by making the robot stop after a couple of steps. Nonetheless, we cannot give a comparable guarantee in collision avoidance for many reasons: impossibility of having absolute knowledge of where people are moving, kinematic/dynamical limitations of the robot, adversarial crowd motion, etc. We address this limitation with a standard strategy for crowd navigation, known as passive safety, that allows us to formulate a unified Model Predictive Control approach for balance and collision avoidance in which we require the robot to stop safely in finite time. In addition, we define a novel safe navigation strategy based on the premise of avoiding collisions for as long as possible that minimizes their occurrence and severity. We propose a lexicographic formulation that produces motions that comply with such premise.We increase the degrees of freedom of the locomotion of a biped robot by allowing the duration and orientation of its steps to vary online. This introduces nonlinearities in the constraints of the optimization problems we solve. We approximate these nonlinear constraints with safe linear constraints so that satisfying the latter implies satisfying the former. We propose a novel method (Safe Sequential Quadratic Programming) that ensures feasible Newton iterates in the solution of nonlinear problems based on this redefinition of constraints.We make a series of simulations of a biped robot walking in a crowd to evaluate the performance of our proposed controllers. We are able to attest the reduction in the number and in the severity of collisions with our proposed navigation strategy in comparison with passive safety, specially when there is uncertainty in the motion of people. We show typical behaviors of the robot that arise when we allow the online variation of the duration and orientation of the steps and how it further improves collision avoidance. We report the computational cost of our proposed numerical method for nonlinear problems in comparison with a standard method. We show that we only need one Newton iteration to arrive to a feasible solution but that the CPU time is dependent on the amount of active set factorizations needed to arrive to the optimal active set.

Made available in DSpace on 2015-03-05T13:58:27Z (GMT). No. of bitstreams: 0 Previous issue date: 23 / Nenhuma / Os atuais centros urbanos concentram uma profusão de indivíduos localizados em estruturas e edificações complexas, como ginásios esportivos, centros comerciais, aeroportos, etc. Estes ambientes são claramente edificações de múltiplos andares e não podem ser representados por uma solução bidimensional em simulações baseadas em física. Este grau de liberdade extra àqueles suportados pelos modelos atuais de simulação, encontrados na literatura, é a limitação destes em simular agentes em terrenos irregulares ou na presença de rampas e escadas. O trabalho desenvolvido nesta dissertação entrantra-se vinculado ao projeto CSHuV, Centro de Simulação de Humanos Virtuais - em colaboração com a HP Brazil R&D-, inserido no contexto do Laboratório CROMOS. Este projeto vem nos últumos anos, modelando, implementando e validando diferentes ambientes para criação e simulação de humanos virtuais. Como resultado desta dissertação, é oferecido o suporte necessário ao projeto para simula ambientes ainda mais complexos através de f / The current urban center concentrate a large number of people located in complex buildings, as shopping centers, airports, etc. These environments are cleary buildings of multiple floors and can not be represented by a bidimensional solution of Physics simulations. This extra freedom degree is the limitation of these 2D models in simulation agents in irregular lands or at the presence of slopes and stairs.The work developed in this master’s thesis is inserted on the CSHuV project, Centro de Simulação de Humanos Virtuais – in collaboration with the HP Brazil R&D - , in the context of CROMOS Laboratory. This project comes, in the last years, modeling, implementing and validating different environments for creation and simulation of virtual human agents. As result of this master’s thesis, the support necessary to the project to simulate more complex environments through physical and mathematical formalism is offered. An expansion of the model of social forces is proposed, allowing the agent space displacements i

The aim of this dissertation is to contribute to research on pay-as-you-go data integration through the proposal of an approach for targeted feedback collection (TFC), which aims to improve the cost-effectiveness of feedback collection, especially when there is uncertainty associated with characteristics of the integration artefacts. In particular, this dissertation focuses on the data source selection task in data integration. It is shown how the impact of uncertainty about the evaluation of the characteristics of the candidate data sources, also known as data criteria, can be reduced, in a cost-effective manner, thereby improving the solutions to the data source selection problem. This dissertation shows how alternative approaches such as active learning and simple heuristics have drawbacks that throw light into the pursuit of better solutions to the problem. This dissertation describes the resulting TFC strategy and reports on its evaluation against alternative techniques. The evaluation scenarios vary from synthetic data sources with a single criterion and reliable feedback to real data sources with multiple criteria and unreliable feedback (such as can be obtained through crowdsourcing). The results confirm that the proposed TFC approach is cost-effective and leads to improved solutions for data source selection by seeking feedback that reduces uncertainty about the data criteria of the candidate data sources.

This thesis investigates variation in human cooperative behaviour in naturally occurring contexts. I critically assess the prevailing consensus on human cooperation derived from laboratory games (such as the dictator and public goods games), by identifying real life analogues and conducting extensive field observation and experiments. My second chapter investigates the importance of context on social behaviour by taking a commonly used laboratory game, the dictator game, and studying analogous behaviour, giving to mendicants in the street. I conclude that individuals cooperate less in the wild than they do in the laboratory and that monetary pay-offs are important in cooperative decision-making. My third chapter examines how social cues influence peoples' likelihood of giving to mendicants. I conclude that increased group size and crowd density negatively affect donation behaviour. My fourth chapter investigates dog fouling in public parks to understand the causes of variation in cheating in a naturally occurring public goods game. I conclude that despite evidence that a social game is being played, the cues that influences decisions are unclear, and behaviour may depend on local social norms. My fifth chapter investigates social influences on red light jumping by cyclists at pedestrian crossings. I find that the probability of cheating is higher with fewer observers and when other cyclists also cheat.

Cette thèse propose un modèle organisationnel et holonique de l'environnement pour la simulation des déplacements de piétons dans des bâtiments. Une foule de piétons peut être considérée comme un système composé d'un grand nombre d'entités en interaction, dont la dynamique globale ne peut se réduire à la somme des comportements de ses composants. La simulation multiniveau fondée sur les modèles multiagents holoniques constitue une approche permettant d'analyser la dynamique de tels systèmes. Elle autorise leur analyse en considérant plusieurs niveaux d'observation (microscopique, mésoscopique et macroscopique) et prend en compte les ressources de calcul disponibles. Dans ces systèmes, l'environnement est considéré comme l'une des parties essentielles. La dynamique des piétons composant la foule est alors clairement distinguée de celle de l'environnement dans lequel ils se déplacent. Un modèle organisationnel décrivant la structure et la dynamique de l'environnement est proposé. L'environnement est structurellement décomposé en zones, sous-zones, etc. Les organisations et les rôles de cet environnement sont projetés dans une société d'agents ayant en charge de simuler la dynamique de l'environnement et les différentes missions qui lui sont classiquement assignées dans les systèmes multiagents. Ce modèle précise également les règles de passage entre deux niveaux d'observation. Ainsi, chaque agent appartenant au modèle de l'environnement tente d'utiliser une approximation des comportements de ses sous-zones afin de limiter la consommation de ressources durant la simulation. La qualité de l'approximation entre ces deux niveaux d'observation est évaluée avec des indicateurs énergétiques. Ils permettent de déterminer si l'agent approxime correctement les comportements des agents associés aux sous-zones. En sus du modèle organisationnel et holonique proposé, nous présentons un modèle concret de la simulation de voyageurs dans un terminal d'aéroport. Ce modèle concret est implanté sur les plateformes JaSIM et Janus. / This work presents a holonic organizational model of the environment for the simulation of pedestrians in buildings. A crowd of pedestrians is considered as a system composed of a large number of interacting entities. The global dynamics of this system cannot be reduced to the sum of the behaviors of its components, Multilevel simulation based on holonic multiagent models is one approach to analyze the dynamics of such systems. It allows their analysis by considering several levels of observation (microscopic, mesoscopic and macroscopic) and the available computing resources. In these systems, the environment is considered as an essential part. The behavior of the crowd is clearly distinguished from the behavior of the environment in which the pedestrians move. An organizational model is proposed to describe the structure and the dynamics of the indoor environment. This environment is structurally divided into areas, sub-areas, etc. Organizations and roles are mapped into a society of agents in charge of simulating the dynamics of the environment and their various missions in multiagent systems. This model also specifies the rules for changing the level of observation dynamically. Thus, each agent belonging to the model of the environment tries to use an approximation of behaviors of its sub-zones, and at the same time to minimize the resource consumption. The quality of the approximation between these two levels is evaluated with energy-based indicators. They help to determine if the agent approximates the behaviors of its sub-agents correctly. In addition to the organizational and holonic model proposed in this work, we present a concrete model of the simulation of passengers in an airport terminal. This concrete model is implemented on the platforms JaSIM and Janus.