El lenguaje Java en la asignatura de Programación Concurrente

En menos de dos años desde su aparición (en mayo de 1995), el lenguaje Java ha tenido una amplia difusión a través de Internet, y está siendo adoptado en los planes de estudios de Informática en muchas universidades de todo el mundo. Varias de las ventajas que ofrece con respecto a otros lenguajes tradicionalmente utilizados para la enseñanza de la programación son: su tamaño reducido, lo que hace que sea fácil de aprender y empezar a utilizar, el ser orientado a objetos, la disponibilidad de herramientas para desarrollar programas Java en distintos entornos, y las facilidades de gestión de gráficos y su integración en la Web. Por lo que se refiere a la programación concurrente, ofrece un modelo sencillo, como parte del propio lenguaje, para definir y gestionar múltiples flujos de ejecución (threads), y primitivas de sincronización (similares al paradigma de monitor) y de control de los flujos de ejecución (wait, notify, interrupt, suspend, resume). Esta ponencia muestra cómo ha sido aplicado a la asignatura de Programación Concurrente en la Escuela Superior de Informática de la Universidad Complutense de Madrid

Peer-to-Peer System Design Trade-Offs: A Framework Exploring the Balance between Blockchain and IPFS

The current state of the Web, which is dominated by centralized cloud services, raises several concerns on different aspects such as governance, privacy, surveillance, and security. A way to address these issues is to decentralize the platforms by adopting new distributed technologies, such as IPFS and Blockchain, which follow a full peer-to-peer model. This work proposes a set of guidelines to design decentralized systems, taking into consideration the different trade-offs these technologies face with regard to their consistency requirements. These guidelines are then illustrated with the design of a decentralized questions and answers system. This system serves to illustrate a framework to create decentralized services and applications, that uses IPFS and Blockchain technologies and incorporates the discussion and guidelines of the paper, providing solutions for data access, data provenance and data discovery. Thus, this work proposes a framework for the design of decentralized systems and contributes a set of guidelines to decide in which cases Blockchain technology may be required, or when other technologies, such as IPFS, are sufficient

Evaluating the Software Frameworks for Developing Decentralized Autonomous Organizations

First Bitcoin in 2008, and later Ethereum in 2014, held a powerful promise: online decentralized governance, without servers or central controllers, not just for finance applications like crypto-currencies but for any organization. The so called Decentralized Autonomous Organizations (DAOs) were expected to fulfill such a promise, enabling people to organize online relying on blockchain-based systems and smart contracts automatizing part of their governance. In 2016, three DAO software frameworks —Aragon, DAOstack and Colony— emerged aiming to facilitate development and experimentation in this field. To which extent do they facilitate DAO development today? This paper performs an analytical comparison of these three frameworks, focusing on their current functionalities for building DAOs. We find Aragon to be the most complete in several aspects. In order to provide more details on the challenges on building DAOs with current frameworks, we present a case study using the Aragon framework. Through this case study, we have piloted DAO development using this framework, and thus we may highlight the benefits, limitations and problems that developers face when adopting it. Our findings show that, even if Aragon does provide superior capabilities to other frameworks, it is still highly challenging to build a DAO with the current tools. Today, problems include issues on software engineering, instability, localization, documentation, lack of formalization and standards, and interoperability. Complementarily, this paper aims to provide some guidance to those developers aiming to face the challenges in developing a DAO, and to those aiming to fix the major weak points that make DAOs the organizations of a still distant future

Foundations for the Design of a Creative System Based on the Analysis of the Main Techniques that Stimulate Human Creativity

This work presents the design of a computational system with creative capacity, based on the synthesis of the main methods that stimulate human creativity. When analyzing each method, a set of characteristics that the computer system must have in order to emulate a creative capacity has been suggested. In this way, by integrating all the suggestions in a structured way, it is possible to design the general architecture and functioning strategy of a computer system that has the incremental creative capacity of well-known creative methods. This computational system is designed as a multi-agent system, made up of two groups of agents, the problem solving group and the creative group, the first one exploring and evaluating paths for suitable solutions, the second implementing creative methods to generate new paths that are provided to the first group

Modelado basado en agentes para el estudio de sistemas complejos

El modelado basado en agentes es una herramienta que en las dos últimas décadas está siendo cada vez más utilizada para el estudio de sistemas complejos en distintos ámbitos de las ciencias sociales y como ayuda para la toma de decisiones. Las entidades de los sistemas sociales pueden ser modeladas como agentes autónomos que interaccionan en un entorno. Estos modelos se pueden simular para analizar el comportamiento que muestra el sistema en distintos escenarios y configuraciones. En este artículo se ilustra su aplicación con varios casos, y se describen las herramientas más utilizadas actualmente, así como los retos metodológicos para su utilización en gran escalaproyectos CSD2010-00034 (CONSOLIDER-INGENIO 2010) y TIN2011-28335-C02-01 subvencionados por el Gobierno de España con referencias, y el proyecto GREX251-2009 subvencionado por la Junta de Castilla y León

Mixed narrative and dialog content planning based on BDI agents

There exist various narrative systems, focused on different parts of the complex process of story generation. Some of them are oriented to content planning, and some to sentence planning, with different properties and characteristics. In this paper we propose a system based on BDI agents that generates stories (creating content, performing content planning and simple sentence planning) with narrative parts and dialogs. The content for the story is generated in a multiagent social simulation system, and the content planning is based on rules and a state space search algorithm based on the system representation of the reader’s perception of the story

Asking the Oracle: introducing forecasting principles into agent-based modelling

This paper presents a set of guidelines, imported from the field of forecasting, that can help social simulation and, more specifically, agent-based modelling practitioners to improve the predictive performance and the robustness of their models. The presentation starts with a discussion on the current debate on prediction in social processes, followed by an overview of the recent experience and lessons learnt from the field of forecasting. This is the basis to define standard practices when developing agent-based models under the perspective of forecasting experimentation. In this context, the guidelines are structured in six categories that correspond to key issues that should be taken into account when building a predictor agent-based model: the modelling process, the data adequacy, the space of solutions, the expert involvement, the validation, and the dissemination and replication. The application of these guidelines is illustrated with an existing agent-based model. We conclude by tackling some intrinsic difficulties that agent-based modelling often faces when dealing with prediction models.project Social Ambient Assisting Living - Methods (SociAAL), supported by Spanish Council for Science and Innovation, with grant TIN2011-28335-C02-01 and the Spanish MICINN project CSD2010-00034 (SimulPast CONSOLIDER-INGENIO 2010). We also thank the support from the Programa de Creación y Consolidación de Grupos de Investigación UCM-BSCH, GR35/10-A (921354

7th International Conference on Practical Applications of Agents and Multi-Agent Systems (PAAMS 2009)

PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2009 edition. These articles capture the most innovative results and this year’s trends: Assisted Cognition, E-Commerce, Grid Computing, Human Modelling, Information Systems, Knowledge Management, Agent-Based Simulation, Software Development, Transports, Trust and Security. Each paper has been reviewed by three different reviewers, from an international committee composed of 64 members from 20 different countries. From the 92 submissions received, 35 were selected for full presentation at the conference, and 26 were accepted as posters

Implementation of context-aware workflows with Multi-agent Systems

Systems in Ambient Intelligence (AmI) need to manage workflows that represent users’ activities. These workflows can be quite complex, as they may involve multiple participants, both physical and computational, playing different roles. Their execution implies monitoring the development of the activities in the environment, and taking the necessary actions for them and the workflow to reach a certain end. The context-aware approach supports the development of these applications to cope with event processing and regarding information issues. Modeling the actors in these context-aware workflows, where complex decisions and interactions must be considered, can be achieved with multi-agent systems. Agents are autonomous entities with sophisticated and flexible behaviors, which are able to adapt to complex and evolving environments, and to collaborate to reach common goals. This work presents architectural patterns to integrate agents on top of an existing context-aware architecture. This allows an additional abstraction layer on top of context-aware systems, where knowledge management is performed by agents.This approach improves the flexibility of AmI systems and facilitates their design. A case study on guiding users in buildings to their meetings illustrates this approach