An MILP model for the plug-in electric vehicle charging coordination problem in electrical distribution systems

A new mixed-integer linear programming (MILP) model is proposed to represent the plug-in electric vehicles (PEVs) charging coordination problem in electrical distribution systems. The proposed model defines the optimal charging schedule for each division of the considered period of time that minimizes the total energy costs. Moreover, priority charging criteria is taken into account. The steady-state operation of the electrical distribution system, as well as the PEV batteries charging is mathematically represented; furthermore, constraints related to limits of voltage, current and power generation are included. The proposed mathematical model was applied in an electrical distribution system used in the specialized literature and the results show that the model can be used in the solution of the PEVs charging problem.

Coordination in the use of money

Fundamental models of money, while explicit about the frictions that render money essential, are silent on how agents actually coordinate in its use. This paper studies this coordination problem, providing an endogenous map between the primitives of the environment and the beliefs on the acceptability of money. We show that an increase in the frequency of trade meetings, besides its direct impact on payo¤s, facilitates coordination. In particular, for a large enough frequency of trade meetings, agents always coordinate in the use of money.

Response threshold models, stochastic learning automata and ant colony optimization-based decentralized self-coordination algorithms for heterogeneous multi-tasks distribution in multi-robot systems

In recent decades, there has been an increasing interest in systems comprised of several autonomous mobile robots, and as a result, there has been a substantial amount of development in the eld of Articial Intelligence, especially in Robotics. There are several studies in the literature by some researchers from the scientic community that focus on the creation of intelligent machines and devices capable to imitate the functions and movements of living beings. Multi-Robot Systems (MRS) can often deal with tasks that are dicult, if not impossible, to be accomplished by a single robot. In the context of MRS, one of the main challenges is the need to control, coordinate and synchronize the operation of multiple robots to perform a specic task. This requires the development of new strategies and methods which allow us to obtain the desired system behavior in a formal and concise way. This PhD thesis aims to study the coordination of multi-robot systems, in particular, addresses the problem of the distribution of heterogeneous multi-tasks. The main interest in these systems is to understand how from simple rules inspired by the division of labor in social insects, a group of robots can perform tasks in an organized and coordinated way. We are mainly interested on truly distributed or decentralized solutions in which the robots themselves, autonomously and in an individual manner, select a particular task so that all tasks are optimally distributed. In general, to perform the multi-tasks distribution among a team of robots, they have to synchronize their actions and exchange information. Under this approach we can speak of multi-tasks selection instead of multi-tasks assignment, which means, that the agents or robots select the tasks instead of being assigned a task by a central controller. The key element in these algorithms is the estimation ix of the stimuli and the adaptive update of the thresholds. This means that each robot performs this estimate locally depending on the load or the number of pending tasks to be performed. In addition, it is very interesting the evaluation of the results in function in each approach, comparing the results obtained by the introducing noise in the number of pending loads, with the purpose of simulate the robot's error in estimating the real number of pending tasks. The main contribution of this thesis can be found in the approach based on self-organization and division of labor in social insects. An experimental scenario for the coordination problem among multiple robots, the robustness of the approaches and the generation of dynamic tasks have been presented and discussed. The particular issues studied are: Threshold models: It presents the experiments conducted to test the response threshold model with the objective to analyze the system performance index, for the problem of the distribution of heterogeneous multitasks in multi-robot systems; also has been introduced additive noise in the number of pending loads and has been generated dynamic tasks over time. Learning automata methods: It describes the experiments to test the learning automata-based probabilistic algorithms. The approach was tested to evaluate the system performance index with additive noise and with dynamic tasks generation for the same problem of the distribution of heterogeneous multi-tasks in multi-robot systems. Ant colony optimization: The goal of the experiments presented is to test the ant colony optimization-based deterministic algorithms, to achieve the distribution of heterogeneous multi-tasks in multi-robot systems. In the experiments performed, the system performance index is evaluated by introducing additive noise and dynamic tasks generation over time.

Essays on coordination problems in economics

No estudo da economia, há diversas situações em que a propensão de um indivíduo a tomar determinada ação é crescente na quantidade de outras pessoas que este indivíduo acredita que tomarão a mesma ação. Esse tipo de complementaridade estratégica geralmente leva à existência de múltiplos equilíbrios. Além disso, o resultado atingido pelas decisões decentralizadas dos agentes pode ser ineficiente, deixando espaço para intervenções de política econômica. Esta tese estuda diferentes ambientes em que a coordenação entre indivíduos é importante. O primeiro capítulo analisa como a manipulação de informação e a divulgação de informação afetam a coordenação entre investidores e o bem-estar em um modelo de corridas bancárias. No modelo, há uma autoridade reguladora que não pode se comprometer a revelar a verdadeira situação do setor bancário. O regulador observa informações idiossincráticas dos bancos (através de um stress test, por exemplo) e escolhe se revela essa informação para o público ou se divulga somente um relatório agregado sobre a saúde do sistema financeiro como um todo. O relatório agregado pode ser distorcido a um custo – um custo mais elevado significa maior credibilidade do regulador. Os investidores estão cientes dos incentivos do regulador a esconder más notícias do mercado, mas a manipulação de informação pode, ainda assim, ser efetiva. Se a credibilidade do regulador não for muito baixa, a política de divulgação de informação é estado-contingente, e existe sempre um conjunto de estados em que há manipulação de informação em equilíbrio. Se a credibilidade for suficientemente baixa, porém, o regulador opta por transparência total dos resultados banco-específicos, caso em que somente os bancos mais sólidos sobrevivem. Uma política de opacidade levaria a uma crise bancária sistêmica, independentemente do estado. O nível de credibilidade que maximiza o bem-estar agregado do ponto de vista ex ante é interior. O segundo e o terceiro capítulos estudam problemas de coordenação dinâmicos. O segundo capítulo analisa o bem-estar em um ambiente em que agentes recebem oportunidades aleatórias para migrar entre duas redes. Os resultados mostram que sempre que a rede de pior qualidade (intrínseca) prevalece, isto é eficiente. Na verdade, um planejador central estaria ainda mais inclinado a escolher a rede de pior qualidade. Em equilíbrio, pode haver mudanças ineficientes que ampliem a rede de qualidade superior. Quando indivíduos escolhem entre dois padrões ou redes com níveis de qualidade diferentes, se todos os indivíduos fizessem escolhas simultâneas, a solução eficiente seria que todos adotassem a rede de melhor qualidade. No entanto, quando há fricções e os agentes tomam decisões escalonadas, a solução eficiente difere ix do senso comum. O terceiro capítulo analisa um problema de coordenação dinâmico com decisões escalonadas em que os agentes são heterogêneos ex ante. No modelo, existe um único equilíbrio, caracterizado por thresholds que determinam as escolhas para cada tipo de agente. Apesar da heterogeneidade nos payoffs, há bastante conformidade nas ações individuais em equilíbrio. Os thresholds de diferentes tipos de agentes coincidem parcialmente contanto que exista um conjunto de crenças arbitrário que justifique esta conformidade. No entanto, as estratégias de equilíbrio de diferentes tipos nunca coincidem totalmente. Além disso, a conformidade não é ineficiente. A solução eficiente apresentaria estratégias ainda mais similares para tipos distintos em comparação com o equilíbrio decentralizado.

Correlated equilibria, good and bad: an experimental study

We report results from an experiment that explores the empirical validity of correlated equilibrium, an important generalization of the Nash equilibrium concept. Specifically, we seek to understand the conditions under which subjects playing the game of Chicken will condition their behavior on private, third–party recommendations drawn from known distributions. In a “good–recommendations” treatment, the distribution we use is a correlated equilibrium with payoffs better than any symmetric payoff in the convex hull of Nash equilibrium payoff vectors. In a “bad–recommendations” treatment, the distribution is a correlated equilibrium with payoffs worse than any Nash equilibrium payoff vector. In a “Nash–recommendations” treatment, the distribution is a convex combination of Nash equilibrium outcomes (which is also a correlated equilibrium), and in a fourth “very–good–recommendations” treatment, the distribution yields high payoffs, but is not a correlated equilibrium. We compare behavior in all of these treatments to the case where subjects do not receive recommendations. We find that when recommendations are not given to subjects, behavior is very close to mixed–strategy Nash equilibrium play. When recommendations are given, behavior does differ from mixed–strategy Nash equilibrium, with the nature of the differ- ences varying according to the treatment. Our main finding is that subjects will follow third–party recommendations only if those recommendations derive from a correlated equilibrium, and further, if that correlated equilibrium is payoff–enhancing relative to the available Nash equilibria.

The Impact of Information Provision on Agglomeration Bonus Performance: An Experimental Study on Local Networks

The Agglomeration Bonus (AB) is a mechanism to induce adjacent landowners to spatially coordinate their land use for the delivery of ecosystem services from farmland. This paper uses laboratory experiments to explore the performance of the AB in achieving the socially optimal land management configuration in a local network environment where the information available to subjects varies. The AB poses a coordination problem between two Nash equilibria: a Pareto dominant and a risk dominant equilibrium. The experiments indicate that if subjects are informed about both their direct and indirect neighbors’ actions, they are more likely to coordinate on the Pareto dominant equilibrium relative to the case where subjects have information about their direct neighbors’ action only. However, the extra information can only delay – and not prevent – the transition to the socially inferior risk dominant Nash equilibrium. In the long run, the AB mechanism may only be partially effective in enhancing delivery of ecosystem services on farming landscapes featuring local networks.

Improving anterior deltoid activity in a musculoskeletal shoulder model - an analysis of the torque-feasible space at the sternoclavicular joint.

Modelling the shoulder's musculature is challenging given its mechanical and geometric complexity. The use of the ideal fibre model to represent a muscle's line of action cannot always faithfully represent the mechanical effect of each muscle, leading to considerable differences between model-estimated and in vivo measured muscle activity. While the musculo-tendon force coordination problem has been extensively analysed in terms of the cost function, only few works have investigated the existence and sensitivity of solutions to fibre topology. The goal of this paper is to present an analysis of the solution set using the concepts of torque-feasible space (TFS) and wrench-feasible space (WFS) from cable-driven robotics. A shoulder model is presented and a simple musculo-tendon force coordination problem is defined. The ideal fibre model for representing muscles is reviewed and the TFS and WFS are defined, leading to the necessary and sufficient conditions for the existence of a solution. The shoulder model's TFS is analysed to explain the lack of anterior deltoid (DLTa) activity. Based on the analysis, a modification of the model's muscle fibre geometry is proposed. The performance with and without the modification is assessed by solving the musculo-tendon force coordination problem for quasi-static abduction in the scapular plane. After the proposed modification, the DLTa reaches 20% of activation.

Dois exercícios de política monetária e fiscal com atuação ótima do Banco Central

O objetivo da tese é analisar questões relativas à coordenação entre as políticas monetária e fiscal no Brasil após a adoção do regime de metas de inflação. Utiliza-se de um modelo de metas de inflação para uma economia pequena e aberta para a incorporação um bloco de equações que descrevem a dinâmica das variáveis fiscais. Tendo por base os conceitos de Leeper (1991), ambas as entidades, Banco Central e Tesouro Nacional, podem agir de forma ativa ou passiva, e será este comportamento estratégico que determinará a eficiência da política monetária. Foram estimados os parâmetros que calibram o modelo e feitas as simulações para alguns dos choques que abalaram a economia brasileira nos últimos anos. Os resultados mostraram que nos arranjos em que a autoridade fiscal reage a aumentos de dívida pública com alterações no superávit primário, a trajetória de ajuste das variáveis frente a choques tende a ser, na maioria dos casos, menos volátil propiciando uma atuação mais eficiente do Banco Central. Nestes arranjos, o Banco Central não precisa tomar para si funções que são inerentes ao Tesouro. Também são analisadas as variações no comportamento do Banco Central e do Tesouro Nacional em função de diferentes composições da dívida pública. Os resultados mostram que a estrutura do endividamento público será benéfica, ou não, à condução das políticas monetária e fiscal, dependendo do tipo de choque enfrentado. O primeiro capítulo, introdutório, procura contextualizar o regime de metas de inflação brasileiro e descrever, sucintamente, a evolução da economia brasileira desde sua implantação. No segundo capítulo são analisados os fundamentos teóricos do regime de metas de inflação, sua origem e principais componentes; em seguida, são apresentados, as regras de política fiscal necessárias à estabilidade de preços e o problema da dominância fiscal no âmbito da economia brasileira. O terceiro capítulo apresenta a incorporação do bloco de equações fiscais no modelo de metas de inflação para economia aberta proposto por Svensson (2000), e as estimações e calibrações dos seus parâmetros para a economia brasileira. O quarto capítulo discute as diferentes formas de coordenação entre as autoridades monetária e fiscal e a atuação ótima do Banco Central. O quinto capítulo tem como base a mais eficiente forma de coordenação obtida no capítulo anterior para analisar as mudanças no comportamento da autoridade monetária e fiscal frente a diferentes estruturas de prazos e indexadores da dívida pública que afetam suas elasticidades, juros, inflação e câmbio.

Demand expectations and the timing of stimulus policies

This paper proposes a simple macroeconomic model with staggered investment decisions. The model captures the dynamic coordination problem arising from demand externalities and fixed costs of investment. In times of low economic activity, a firm faces low demand and hence has less incentives for investing, which reinforces firms’ expectations of low demand. In the unique equilibrium of the model, demand expectations are pinned down by fundamentals and history. Owing to the beliefs that arise in equilibrium, there is no special reason for stimulus at times of low economic activity.

Contágio no modelo de Allen e Gale com infraestrutura bancária endógena

Neste trabalho investigamos a formação de network considerando agentes cautelosos. O modelo consiste em duas regiões com (n/2) bancos em cada, onde a interligação entre eles ocorre através e depósitos interbancários. Cada banco está sujeito a corrida bancária, ou devido a um choque negativo de agentes impacientes, ou devido a contaminação da corrida de um banco pertencente a infraestrutura bancária. Os bancos podem tentar eliminar a possibilidade de contágio ao fazer um número alto de inter-ligações. Para isso, é necessário uma coordenação entre todos os bancos. Se um banco não se prevenir de um contágio, ele impõe a todos os outros a possibilidade de contágio no pior cenário. Há duas regiões bem definidas de equilíbrio de nash simétrico com network estável, uma na qual todos os bancos se previnem do cenário de contágio no pior cenário e a outra na qual nenhum banco se previne. Devido ao problema de coordenação, o equilíbrio com contágio no pior cenário pode ocorrer mesmo sendo pareto dominado pelo equilíbrio sem contágio. Sob certas condições, o equilíbrio com contágio ocorre com um network pareto eficiente. Neste caso o network eficiente é diferente do network mais resiliente ao contágio.

The Entrepreneurial Theory of the Firm and the Theory of the Entrepreneurial Firm

The entrepreneurial theory of the firm argues that entrepreneurship, properly understood, is a crucial but neglected element in explaining the nature and boundaries of the firm. By contrast, the theory of the entrepreneurial firm presumably seeks not to understand the nature and boundaries of "the firm" in general but rather to understand a particular type of firm: one that is entrepreneurial. This paper is an attempt to reconcile the two. After briefly delving for the concept of entrepreneurship in the work of Schumpeter, Kirzner, and (especially) Knight, the paper makes the case for the entrepreneurial theory of the firm. In such a theory, the firm exists as the solution to a coordination problem in a world of change and uncertainty, including Knightian or structural uncertainty. Taking a historical or developmental perspective, the paper then examines the changing nature of the entrepreneurial coordination problem over the life-cycle. In this formulation, "the entrepreneurial firm" is a nascent firm or proto-firm facing a problem of coordinating systemic change in economic capabilities. Lacking (by definition) adequate guidance from existing systems of rules of conduct embedded in markets or organizations, the entrepreneurial firm typically relies on a form of organization Max Weber called charismatic authority. In the end, although there is no such thing as a non-entrepreneurial firm, firms that must solve coordination problems in a world of novelty and systemic change ("entrepreneurial firms") are perhaps the purest case of the entrepreneurial theory of the firm.

Context-awareness in task automation services by distributed event processing

Everybody has to coordinate several tasks everyday, usually in a manual manner. Recently, the concept of Task Automation Services has been introduced to automate and personalize the task coordination problem. Several user centered platforms and applications have arisen in the last years, that let their users configure their very own automations based on third party services. In this paper, we propose a new system architecture for Task Automation Services in a heterogeneous mobile, smart devices, and cloud services environment. Our architecture is based on the novel idea to employ distributed Complex Event Processing to implement innovative mixed execution profiles. The major advantage of the approach is its ability to incorporate context-awareness and real-time coordination in Task Automation Services.

Partial Cooperation in Location Choice: Salop’s Model with Three Firms

We consider how three firms compete in a Salop location model and how cooperation in location choice by two of these firms affects the outcomes. We con- sider the classical case of linear transportation costs as a two-stage game in which the firms select first a location on a unit circle along which consumers are dispersed evenly, followed by the competitive selection of a price. Standard analysis restricts itself to purely competitive selection of location; instead, we focus on the situation in which two firms collectively decide about location, but price their products competitively after the location choice has been effectuated. We show that such partial coordination of location is beneficial to all firms, since it reduces the number of equilibria significantly and, thereby, the resulting coordination problem. Subsequently, we show that the case of quadratic transportation costs changes the main conclusions only marginally.

AI and legal personhood: a theoretical survey

I set out the pros and cons of conferring legal personhood on artificial intelligence systems (AIs), mainly under civil law. I provide functionalist arguments to justify this policy choice and identify the content that such a legal status might have. Although personhood entails holding one or more legal positions, I will focus on the distribution of liabilities arising from unpredictably illegal and harmful conduct. Conferring personhood on AIs might efficiently allocate risks and social costs, ensuring protection for victims, incentives for production, and technological innovation. I also consider other legal positions, e.g., the capacity to act, the ability to hold property, make contracts, and sue (and be sued). However, I contend that even assuming that conferring personhood on AIs finds widespread consensus, its implementation requires solving a coordination problem, determined by three asymmetries: technological, intra-legal systems, and inter-legal systems. I address the coordination problem through conceptual analysis and metaphysical explanation. I first frame legal personhood as a node of inferential links between factual preconditions and legal effects. Yet, this inferentialist reading does not account for the ‘background reasons’, i.e., it does not explain why we group divergent situations under legal personality and how extra-legal information is integrated into it. One way to account for this background is to adopt a neo-institutional perspective and update its ontology of legal concepts with further layers: the meta-institutional and the intermediate. Under this reading, the semantic referent of legal concepts is institutional reality. So, I use notions of analytical metaphysics, such as grounding and anchoring, to explain the origins and constituent elements of legal personality as an institutional kind. Finally, I show that the integration of conceptual and metaphysical analysis can provide the toolkit for finding an equilibrium around the legal-policy choices that are involved in including (or not including) AIs among legal persons.