Abstract: Software reliability refers to the ability of a system to perform its intended function under specified conditions for a specified period of time. The first critical step in the software reliability testing process is to create a Software Operational Profile (SOP). Several methodologies for creating SOP have been proposed. Nonetheless, nearly all the proposed studies have neglected the uniqueness of the new software paradigms, despite the fact that these are generally distinguished by their own concepts and methodologies. One of these software paradigms is multi-agent systems. Rather than using a generic one, it would be more useful to propose a…specific methodology for creating SOP. In this paper, we propose a methodology for developing Operational Profile for specific kinds of multi-agent systems (so-called normative multi-agent systems). A detailed case study is used to demonstrate this methodology.
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Keywords: Software operational profile, reliability testing process, normative multi-agent systems
Abstract: In this work, we propose a new distributed dynamic planning approach based on constraint satisfaction, able to take into account the satisfaction of the constraints in all new versions of generated plans. Our approach is to generate, a new plan by each agent, whenever there is a change in its set of actions to plan caused by the unpredictable changes of the environment. This does not alter the satisfaction of the constraints taken into account during the generation of the initial plan. Our approach allows the integration of all the new actions, generated by the changes, in the new plan…at the right place, which preserves the satisfaction of the constraints. For this, the approach uses genetic algorithm where the fitness function is defined on the basis of the constraints to be satisfied. The proposed approach is supported by a formal framework and applied on a concrete case study to illustrate and show its usefulness.
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Abstract: Formal semantics provide precise specifications of the expected behavior of organizational model based on multi-agent system, allowing users to understand them and also modelers to reason about them and to prove their correctness. A first step was described to provide a formal specification framework among organization-centered multi-agent system by using an existing rewriting logic language called Maude to translate organizational models, which allows addressing these issues. Such formalization provides additional benefits, such as enabling the simulation of the specifications or giving access to the Maude toolkit to reason about them. In this paper, Maude was used to formally describe Agent-Group-Role-based-organization…specifications. The proposed framework could, in fact, be used as is or with some extensions to describe other agent organization models. Actually, the results of precedent works [31 , 32 ] were synthesized with additional extensions related to the formal description of the Agent-Group-Role model. This approach is illustrated using the supply chain management (SCM) case study.
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Abstract: In multi-agent systems, the yellow pages service is very important for agents to be able to interact with each other. The more the number of agents is high, the more performance degradation will result, due to the overload of requests sent to central yellow pages. This issue didn’t get much attention from researchers despite its importance. The proposed approach for solving this scalability issue is based on the aspect-oriented paradigm. An aspect was used to play the roles of a replicator and a distributor of requests to several new yellow pages. The use of aspect-oriented programming simplifies the implementation, reduces…the maintenance effort and offers a good reusability of the proposed solution. The approach is validated on three JADE applications and evaluated on five different machines. Results, which are very promising, show a significant scalability and performance improvement of the yellow pages service especially on Linux operating system.
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Keywords: Perfective maintenance, performance, scalability, yellow pages, multi-agent systems
Abstract: Software preventive maintenance is an important software activity which consists to include modifications and updations in order to prevent future serious issues of the software. In the context of multi-agent systems, such activity is completely omitted. The inherent specificities of multi-agent systems (e.g., autonomy, pro-activity, reactivity, adaptability, etc.) make their maintenance difficult task to achieve. We propose, in this paper, a conditional preventive maintenance approach for multi-agent applications. The proposed approach is based on MAS quality measurements and uses Aspect-Oriented programming. The proposed approach consists of three major steps, (i) measuring two quality metrics (autonomy and sociability) of the running…application in a dynamic and continuous way by using AspectJ code and comparing them with minimum thresholds previously defined by the designer, (ii) warning the maintainer in case of detection of abnormal regression of the MAS quality, and (iii) intervention of the maintainer for preserving the application quality and thus avoid potential damage. The proposed approach is supported by a software tool we developed called PMMAS (Preventive Maintenance of Multi-Agent Systems). The approach and the associated tool are illustrated using a concrete case study.
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Abstract: In Open Multi-Agent Systems (Open MAS), no central authority can control all the agents. The agents share some features like: heterogeneity, different aims and objectives, autonomy, self-interested that conflicts individual goals and limited trust. Also, agents, in Open MAS, can enter and leave a system at any time. In order to ensure that the system carries out its goals, it must be observed and controlled. For that, it is necessary to define monitoring mechanisms for: (1) understanding and analyzing the system behavior, and (2) helping developers to review and examine, at run-time, agents’ communications and other different events (agents’ lifecycle,…agent requested roles, performed actions by a given agent, etc.) generated during the system execution. In this paper, an AOP-based approach for monitoring Open MAS is proposed. The proposed approach is supported by RT-MTOMAS (Real-Time Monitoring Tool for Open Multi-Agent Systems), a new tool we developed for dealing with Open MAS monitoring issues. RT-MTOMAS provides, also, a behavioral model in order to illustrate agents’ interactions. The developed tool is illustrated through a concrete case study. We outlined its integration with MaDKit agent platform.
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Keywords: Open MAS, AGR (agent, group, role), AGR-based open MAS, Run-Time Monitoring, AOP (Aspect Oriented Programming), MaDKit
Abstract: In this paper, we present a formal and systematic approach allowing translating the specification of the interactions between agents, described using AUML formalism, in a Maude specification. Based on rewriting logic, the formal and object-oriented language Maude offers an interesting way for concurrent systems formal specification and programming. The main objectives of our approach are essentially: (1) to specify formally multi-agent systems behavior and, (2) to provide a healthy description preserving the consistency in their behavior and supporting their verification and validation process. The Maude descriptions, generated in the context of the developed framework, have been validated using the platform…supporting the Maude language.
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Abstract: Multi-agent systems are proposed as a solution to mitigate nowadays software requirements: open and distributed architectures with dynamic and adaptive behaviour. Like any other software, multi-agent systems development process is error-prone; thus testing is a key activity to ensure the quality of the developed product. This paper sheds light on agent testing as it is the primary artefact for any multi-agent system’s testing process. A framework called JADE Testing Framework (JTF) for JADE platform’s agent testing is proposed. JTF allows testing agents at two levels: unit (inner-components) and agent (agent interactions) levels. JTF is the result of the integration of…two testing solutions: JAT a well-known framework for JADE’s agent’s interaction testing and UJade, a new solution that was developed for agent’s unit testing. UJade provides also a toolbox that allows for enhancing JAT capabilities. The evidence of JTF usability and effectiveness in JADE agent testing was supported by an empirical study conducted on seven multi-agent systems. The results of the study show that: when an agent’s code can be tested either at agent or unit levels UJade is less test’s effort consuming than JAT; JTF provides better testing capabilities and the developed tests are more effective than those developed using UJade or JAT alone.
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