Celia Gutiérrez

National culture and leadership profiles in Europe: Some results from the GLOBE study.

Different cultural groups may have different conceptions of what leadership should entail, i.e. different leadership prototypes. Several earlier studies revealed that within Europe various cultural clusters can be distinguished (Hofstede, 1991; Ronen & Shenkar, 1985). Using recent data from the GLOBE project, this article discusses similarities and differences on culture and leadership dimensions among 21 European countries. The results show that two broad clusters or patterns of cultural values can be distinguished, contrasting the North-Western and South-Eastern part of Europe. Within these clusters, differences in leadership prototypes to a certain extent mirror differences in culture. On the basis of these results it is hardly possible to speak of a single typically European culture or one distinct European management style. However, on some dimensions European scores are different from at least some other regions in the world.

Modular design of a hybrid genetic algorithm for a flexible job-shop scheduling problem

The aim of the job-shop scheduling problem is to optimize the task planning in an industrial plant satisfying time and technological constraints. The existing algorithmic and mathematical methods for solving this problem usually have high computational complexities making them intractable. Flexible job-shop scheduling becomes even more complex, since it allows one to assign each operation to a resource from a set of suitable ones. Alternative heuristic methods are only able to satisfy part of the constraints applicable to the problem. Moreover, these solutions usually offer little flexibility to adapt them to new requirements. This paper describes research within heuristic methods that combines genetic algorithms with repair heuristics. Firstly, it uses a genetic algorithm to provide a non-optimal solution for the problem, which does not satisfy all its constraints. Then, it applies repair heuristics to refine this solution. There are different types of heuristics, which correspond to the different types of constraints. A heuristic is intended to evaluate and slightly modify a solution that violates a constraint in a way that avoids or mitigates such violation. This approach improves the adaptability of the solution to a problem, as some changes can be addressed just modifying the considered chromosome or heuristics. The proposed solution has been tested in order to analyse its level of constraint satisfaction and its makespan, which are two of the main parameters considered in these types of problems. The paper discusses this experimentation showing the improvements over existing methods.

Agent-oriented modeling and development of a system for crisis management

The management of crisis situations has been a challenging problem from different points of views, such as communication efficiency and avoiding casualties. This paper presents a novel approach that includes an interaction organization pattern for Multi-agent Systems (MASs) in crisis management, abstracted from several existing case studies in which the agents follow a sequence of interactions and the organization must optimize the use of human resources. The pattern considers an emergent organization of peers that adopt different roles according to the circumstances. The key features of the organization are its robustness, scalability (in terms of both agents and roles), flexibility to deal with a changing environment, and the efficient use of resources. In order to validate the organization, the paper presents its modeling and development with the Ingenias methodology, conforming the corresponding MAS. This development follows a model-driven approach, which allows a smooth transition from the specification to the code, and a low-cost testing of the system with different settings. Another key aspect is the application of metrics for validating and improving the MAS in terms of response time. The MAS has been tested with 600 agents representing 200 citizens, showing its performance.

The INGENIAS Development Kit: A Practical Application for Crisis-Management

The INGENIAS Development Kit (IDK) supports the development of fully functional Multi-agent Systems (MASs) from specification models, following a model-driven approach. This paper presents a practical application about crisis-management, in order to provide a full example of application of the IDK tool; and consequently, the specification and the code of this system are included in the IDK 2.8 distribution. The presented application manages the crisis situation of a city, in which, a poisonous material is released, and the central services are not enough to heal all the affected people. The software engineering process of the presented MAS application covers the following phases: specification, model design, implementation, and testing. Both the number of interactions and the number of participants are economized in order to increase the network efficiency, due to the real-time necessity of the MAS application.

Re-thinking simulation: a methodological approach for the application of data mining in agent-based modelling

Agent-based models informed by empirical data are growing in popularity. Many models make extensive use of collected data for the development, initialisation or validation. In parallel, models are growing in size and complexity, generating large amounts of output data. On the other hand, Data Mining is used to extract hidden patterns from large collections of data using different techniques. This work proposes the intense use of Data Mining techniques for the improvement and development of agent-based models. It presents a methodological approach explaining why and when to use Data Mining, with a formal description of each stage of the corresponding process. This is illustrated with a case study, showing the application of the proposed approach step by step.

An analysis architecture for communications in multi-agent systems

Evaluation tools are significant from the Agent Oriented Software Engineering (AOSE) point of view. Defective designs of communications in Multi-agent Systems (MAS) may overload one or several agents, causing a bullying effect on them. Bullying communications have avoidable consequences, as high response times and low quality of service (QoS). Architectures that perform evaluation functionality must include features to measure the bullying activity and QoS, but it is also recommendable that they have reusability and scalability features. Evaluation tools with these features can be applied to a wide range of MAS, while minimizing designer�s effort. This work describes the design of an architecture for communication analysis, and its evolution to a modular version, that can be applied to different types of MAS. Experimentation of both versions shows differences between its executions.

Overlap Algorithms in Flexible Job-shop Scheduling

The flexible Job-shop Scheduling Problem (fJSP) considers the execution of jobs by a set of candidate resources while satisfying time and technological constraints. This work, that follows the hierarchical architecture, is based on an algorithm where each objective (resource allocation, start-time assignment) is solved by a genetic algorithm (GA) that optimizes a particular fitness function, and enhances the results by the execution of a set of heuristics that evaluate and repair each scheduling constraint on each operation. The aim of this work is to analyze the impact of some algorithmic features of the overlap constraint heuristics, in order to achieve the objectives at a highest degree. To demonstrate the efficiency of this approach, experimentation has been performed and compared with similar cases, tuning the GA parameters correctly.

Detection of Overworked Agents in INGENIAS

Overworking behaviors appear in multi-agent systems communication quite often. This occurs when an agent receives many messages in a short period of time. As the agent pays attention to the large amount of messages it worsens its performance, causing the system’s performance to worsen as well. The reasons for this behavior are varied and depend on the nature of the messages: an agent that sends messages to the same agent when it should have sent it to a group of agents in a balanced way; an agent that does not receive a quick response becomes impatient and keep on sending the same message to the same agent until it gets a response, and so on. This article presents a technique that detects the overworked agents in INGENIAS with a new metric and efficiently measures it with a new version of the INGENIAS Development Kit. The experimentation of this technique advocates that the existence of overworked agents is strongly related with the quality of service of multi-agent systems.

Analysis of Bullying in Cooperative Multi-agent Systems' Communications

Cooperative Multi-agent Systems frameworks do not include modules to test communications yet. The proposed framework incorporates robust analysis tools using IDKAnalysis2.0 to evaluate bullying effect in communications. The present work is based on ICARO-T. This platform follows the Adaptive Multi-agent Systems paradigm. Experimentation with ICARO-T includes two deployments: the equitative and the authoritative. Results confirm the usefulness of the analysis tools when exporting to Cooperative Multi-agent Systems that use different configurations. Besides, ICARO-T is provided with new functionality by a set of tools for communication analysis.

An Exploratory Analysis for Designing Robust Interactions in Multi-Agent Systems

In large multi-agent system (MAS), the definition of protocols between pairs of agents is not enough for guaranteeing the absence of undesirable communication organizations and the presence of desirable ones. This paper presents a technique and a tool for designing robust MAS communication architectures. In particular, in the proposed technique, designers are not only recommended to design the desired communication protocols, but also the undesired ones and the organization structures. The proposed tool performs data mining and on-line analytical processing (OLAP) on the logs of execution of MAS that use the Foundation for Intelligent Physical Agents (FIPA) protocol, in order to debug MAS communication architectures. The experimental results advocate that this approach is useful for MAS debugging and testing.