800 research outputs found
Descrição do sistema de contabilidade, em conformidade com a proposta de La Jarne
No full textAccounting systems is one of the four areas of study that developsinternational accounting. This article is the product of the research project “Characterization of the Colombian Accounting System” that considered the Jarne´s proposal from a descriptive approach. To do so, we show the Jarne´s proposed structure of an accounting system, based on it, we describe the current state in Colombia of the five subsystems: regulatory, accounting principles, professional, education, and information and valuation practices. It is evident that from the current regulatory change to accounting and public accounting in Colombia, the accounting system has undergone significant structural changes. For example, weaknesses in education and in the profession itself, and the technical, surveillance and disciplinary agencies, that do not allow sufficient maturity to cope with the requirements of adopting the international model.Una de las cuatro áreas de estudio que desarrolla la contabilidad internacional es la de sistemas contables. Este artículo es producto del proyecto de investigación “Caracterización del Sistema Contable Colombiano”, que tomó la propuesta de J. I. Jarne desde un enfoque descriptivo. Para ello, se presenta la propuesta de estructuración de un sistema contable de este autor, con base en la cual se describe el estado actual en Colombia de los cinco subsistemas: regulatorio, de principios contables, profesional, de formación, y de prácticas de información y valoración. Se evidencia que frente al actual cambio de regulación para la contabilidad y la contaduría pública en Colombia, el sistema contable ha sufrido importantes cambios estructurales. Se encuentran, por ejemplo, debilidades en la formación y la profesión, y los organismos técnicos, de vigilancia y disciplinarios que no permiten enfrentar con la suficiente madurez los requerimientos que conlleva la adopción del modelo internacional.Une des quatre domaines d’étude qui développe la comptabilité internationale est de systèmes comptables. Cet article est le produit du projet de recherche “caractérisation du système comptable colombien”, qui a pris la proposition de J. I. Jarne depuis une approche descriptif. Pour cela, on présente la proposition de conception d’un système comptable de cet auteur, sur la base de laquelle on a décrit l’état actuel en Colombie des cinq sous-systèmes : réglementation, de principes comptables, professionnel, de formation et de pratiques d’information et d’évaluation. Il apparaît clairement que face à l’actuel changement de réglementation pour la comptabilité et la comptabilité publique en Colombie, le système comptable a subi des changements structurels importants. On trouve, par exemple, des faiblesses dans la formation et la profession et les organismes techniques, de surveillance et disciplinaires qui ne permettent pas de faire face avec la maturité suffisante des besoins qu’entraîne l’adoption du modèle international.Uma das quatro áreas de estudo que desenvolve normas internacionais de contabilidade é dos sistemas contabilísticos. Este artigo é produto do projeto de pesquisa “Caracterização do sistema de contabilidade da Colômbia”, que teve a proposta de J. I. Jarne a partir de uma abordagem descritiva. Para isso, é apresentada a proposta para a estruturação de um sistema de contabilidade de este autor, com base no qual descreve oestado atual dos cinco subsistemas: o quadro regulamentar, princípios de contabilidade, profissional, treinamento e práticas de informação e de avaliação. É evidente que a actual mudança de regulamento para a contabilidade e contabilidade pública na Colômbia, o sistema de contabilidade tem sofrido grandes mudanças estruturais. Há, por exemplo, deficiéncias na formação, e a profissão, e a agéncias técnicas, monitoramento e processos disciplinares que não permitem enfrentar com maturidade suficiente as necessidades relacionadas com a adopção do modelo internacional
ELdO6
No full textThe six volumes in this series have each the same structure consisting of sixteen parts. Part VI is Los Animales Hablan: La Fabula. Here in Volume VI this part begins on 65 and runs through 76. The T of C at the beginning notes the author of each of the individual fables, here Aesop, G. Civinini, or L. Clasio. The first of the fables here has delightful illustrations across its three pages. El Cangrejo Astuto tells how the crab beats the fox in a race (67-69). There is a lovely illustration of an almond tree on 70. None of the fable illustrations presented in this volume are signed.Language note: SpanishOriginal language: itaBenjamin Jarne
Efficient Communication in Robust Multi-agent Reinforcement Learning: Trading Observational Robustness for Fewer Communications
No full textReinforcement learning, especially deep reinforcement learning, has made many advances in the last decade. Similarly, great strides have been made in multi-agent reinforcement learning. Systems of cooperative autonomous robots are increasingly being used, for which multi-agent reinforcement learning can be used as a training method. However, the curse of dimensionality remains a problem for the computational speed of the learning algorithm and the bandwidth of communication channels. This research will focus mainly on reducing the problem of overloading communication channels by trying to reduce the number of communications. This is possible since it is usually unnecessary for every agent to communicate with every other agent constantly. To do this, we use some ideas by Daniel Jarne Ornia. The first is to reduce communications in a multi-agent reinforcement learning system by treating it as an event-triggered control problem. This method uses so-called robustness surrogates as an equivalent to a Lyapunov function to determine if a communication can be skipped without decreasing the performance more than some tolerance. The second is a method to increase the observational robustness of a policy by using lexicographic reinforcement learning. We aim to combine these ideas and trade the additional observational robustness for decreased communications. We also want to test whether additional observational robustness can help mitigate the sim-to-real gap. We implement this method for the multi-agent deep deterministic policy gradient algorithm and perform tests on a variant of the predator-prey domain in increasingly more realistic simulations. We found that the combination of this robust policy and the robustness surrogates method does enable the agents to achieve the same return while communicating less. Unfortunately, our research shows that the observational robustness obtained using lexicographic reinforcement learning, does not help mitigate the sim-to-real gap.Double degree in Systems and Control and Robotics at Delft University of Technology https://github.com/J-deGooijer/Efficient-Communication-in-Robust-Multi-agent-Reinforcement-Learning GitHub repositoryMechanical Engineering | Systems and ControlMechanical Engineering | Vehicle Engineering | Cognitive Robotic
ELdO5
No full textThe six volumes in this series have each the same structure consisting of sixteen parts. Part VI is Los Animales Hablan: La Fabula. Here in Volume V this part begins on 71 and runs through 84. The T of C at the beginning notes the author of one of the individual fables, here La Fontaine for El gallo victorioso. The other authors are anonymous. El gallo victorioso, by the way, does not run its usual course into the presence of a larger bird who attacks the proud victorious cock. It finishes rather with a comment that the chickens go off talking as though nothing had happened. The special gift of this series, I think, lies in the brightly colored illustrations that interact with the text. The three storeys of young are presented well in The Eagle, the Cat, and the Sow (76). Tapia's figures for El Pollito Embustero (82-83) make a delightful parade. Two of the fables presented in this volume are signed Mateldi and two Alma Tapia.Language note: SpanishOriginal language: itaBenjamin Jarne
Event-Based Communication in Distributed Q-Learning
No full textWe present an approach to reduce the communication of information needed on a Distributed Q-Learning system inspired by Event Triggered Control (ETC) techniques. We consider a baseline scenario of a Distributed Q-Learning problem on a Markov Decision Process (MDP). Following an event-based approach, N agents sharing a value function explore the MDP and compute a trajectory-dependent triggering signal which they use distributedly to decide when to communicate information to a central learner in charge of computing updates on the action-value function. These decision functions form an Event Based distributed Q learning system (EBd-Q), and we derive convergence guarantees resulting from the reduction of communication. We then apply the proposed algorithm to a cooperative path planning problem, and show how the agents are able to learn optimal trajectories communicating a fraction of the information. Additionally, we discuss what effects (desired and undesired) these event-based approaches have on the learning processes studied, and how they can be applied to more complex multi-agent systems.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Manuel Mazo J
ELdO4
No full textThe six volumes in this series have each the same structure consisting of sixteen parts. Part VI is Los Animales Hablan: La Fabula. Here in Volume IV this part begins on 67 and runs through 78. The T of C at the beginning notes the authors of the individual fables, here La Fontaine or L. Clasio. The special gift of this series, I think, lies in the brightly colored illustrations that interact with the text. The artist has fun, for example, with the wolf whom the horse kicks into the arms of a fox (71). The first of Clasio's fables has an imprudent spider spin her web using the horns of a stag sleeping under a tree (72). Mateldi has a great time again with the characters and spectators in TT (76-78). Two of the four fables presented in this volume are signed Mateldi.Language note: SpanishOriginal language: itaBenjamin Jarne
Convergence of ant colony multi-agent swarms
No full textAnt Colony algorithms are a set of biologically inspired algorithms used commonly to solve distributed optimization problems. Convergence has been proven in the context of optimization processes, but these proofs are not applicable in the framework of robotic control. In order to use Ant Colony algorithms to control robotic swarms, we present in this work more general results that prove asymptotic convergence of a multi-agent Ant Colony swarm moving in a weighted graph.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Tamas Keviczk
Efficient Control for Cooperation: Communication, Learning and Robustness in Multi-Agent Systems
No full textBesides facing the same challenges as single-agent systems, the distributed nature of complex multi-agent systems sparks many questions and problems revolving around the constraints imposed by communication. The idea that multi-agent systems require communication to access information, to coordinate or simply to sense the environment they are acting on is sometimes overlooked when thinking of (and solving) emerging theoretical challenges. However, research problems related to communication in Cyber-Physical Systems have been a prevalent target for network control research for decades. In particular, we take inspiration on Event Triggered Control to study how communication affects performance, safety and robustness in multi-agent systems. The work in this dissertation begins by covering a communication-based form of swarm robotics systems, where taking inspiration from ants, agents learn to forage cooperatively by communicating through the environment. We study what form of convergence guarantees we can derive in such systems and how these depend on the communication logic, proposing mean field formulations of such systems. We then draw an analogy between such learning-based swarms and distributed Reinforcement Learning (RL), and propose strategies to safely reduce communication of information in a general form of distributed Q-Learning problems. We extend these ideas to cooperative Multi-Agent RL systems where agents communicate state measurements with each-other, and define so-called robustness surrogate functions (value function robustness certificates). These certificates allow agents to distributedly estimate how robust the joint policies are against lack of information, and determine when do they need to update other agents with new measurements. At last, we look into the general problem of robust control in RL systems, and propose a characterization of policy robustness against state measurement noise that allows us to cast robustness as a secondary objective in a lexicographic optimization scheme, applicable to policy gradient algorithms. This answers the following premise: If we need to learn controllers that are then deployed in possibly uncertain environments, we may want to make sure that “robustifying” the controller does not decrease (excessively) the capacity of the controller to successfully solve the original problem (without uncertainty).The work presented through this dissertation covers different problems and jumps between overlapping fields, but the methods and techniques proposed share a common principle: As complex multi-agent systems become more applicable to engineering problems, the need for understanding (and simplifying) communication rules is increasingly motivated by safety. Therefore, the problems and solutions considered aim to advance towards a formal understanding and design of communication logic in complex, model free multi-agent systems
Mean Field Behavior of Collaborative Multiagent Foragers
No full textCollaborative multiagent robotic systems, where agents coordinate by modifying a shared environment often result in undesired dynamical couplings that complicate the analysis and experiments when solving a specific problem or task. Simultaneously, biologically inspired robotics rely on simplifying agents and increasing their number to obtain more efficient solutions to such problems, drawing similarities with natural processes. In this work, we focus on the problem of a biologically inspired multiagent system solving collaborative foraging. We show how mean field techniques can be used to re-formulate such a stochastic multiagent problem into a deterministic autonomous system. This de-couples agent dynamics, enabling the computation of limit behaviors and the analysis of optimality guarantees. Furthermore, we analyse how having finite number of agents affects the performance when compared to the mean field limit and we discuss the implications of such limit approximations in this multiagent system, which have impact on more general collaborative stochastic problems.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Manuel Mazo J
ELdO3
No full textThe six volumes in this series have each the same structure consisting of sixteen parts. Part VI is Los Animales Hablan: La Fabula. Here in Volume III this part begins on 71 and runs through 82. The T of C at the beginning notes the authors of the individual fables, here Aesop or La Fontaine. The special gift of this series, I think, lies in the brightly colored illustrations that interact with the text. In LM (73-75), the teamwork of the group of mice is part of both the story and the visual presentation of the story. Mateldi's depiction of the netted lion is a triumph of suggestive lines. Another fine single illustration is that showing the hawk lifting the mouse and frog into the air (77). In this version, it seems that both frog and mouse had in mind to eat the other. Uno y otra pagaron así su mala fe (77). I enjoy the mouse that goes out to adventure in the world, only to get clamped inside an oyster (82). LM alone of the four fables presented in this volume is signed Mateldi.Language note: SpanishOriginal language: itaBenjamin Jarne
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