Salima Hassas

Self-organisation: paradigms and applications

A self-organising system functions without central control, and through contextual local interactions. Components achieve a simple task individually, but a complex collective behaviour emerges from their mutual interactions. Such a system modifies its structure and functionality to adapt to changes to requirements and to the environment based on previous experience. Nature provides examples of self-organisation, such as ants food foraging, molecules formation, or antibodies detection. Similarly, current software applications are driven by social interactions (negotiations, transactions), based on autonomous entities or agents, and run in highly dynamic environments. The issue of engineering applications, based on the principles of self-organisation to achieve robustness and adaptability, is gaining increasing interest in the software research community. The aim of this paper is to survey natural and artificial complex systems exhibiting emergent behaviour, and to outline the mechanisms enabling such behaviours.

A distributed Intrusion Detection and Response System based on mobile autonomous agents using social insects communication paradigm

Abstract The ever increasing connectivity of current computer environments makes traditional Intrusion and Detection Systems more and more inefficient. The ability of moving processes across networks brings new security problems, but also gives us new ways of dealing with these environments. In this paper, we propose an architecture for a distributed stealth Intrusion Detection and Response System (IDRS) based on mobile agents mimicking behaviors of social insects. We present the motivations of an approach that solves several problems actually unchallenged and offers many new ways of thinking future IDRSs. We also depict the foundations of our architecture, discuss its main points, and expose partial results obtained from a prototype. Finally, implementation issues and future work are presented.

Cooperative highway traffic

As cooperative systems (connected vehicles) enable communication and the exchange of information between vehicles and infrastructure, the communication capabilities are expected to lead to better active traffic management on urban motorways. Technological constraints must be the basis for any management strategy. If communication has been analytically proved to help stabilize traffic flow at a microscopic level, then realistic communication strategies should be evaluated by taking into consideration multiple perturbations such as sensor faults and driver cooperation. In this study, a three-layer multiagent framework was used to model and control the homogenization of traffic flow. The physical layer coordinated vehicle dynamics on the basis of a cooperative car-following model. This layer included cooperation derived from the communication and trust layers that, respectively, managed information and its reliability. Simulation results highlight the positive impacts of communication and control on the stability of traffic flow.

WS-Advisor: A Task Memory for Service Composition Frameworks

With the proliferation of Web services, it is becoming increasingly important to support the users in selecting the most appropriate compositions of services for a task. We propose a new service discovery and selection framework that utilises the concept of task memories and a social network of task memories. A task memory captures the service composition history and their meta-data such as associated context and user rating. A network of task memories is formed to realise an effective task memory sharing platform among the users.

Combining Trust and Self-Organization for Robust Maintaining of Information Coherence in Disturbed MAS

This paper addresses the issue of maintaining information coherence and its robustness in a multi-agent system (MAS), that collectively gathers information from distributed sources and where some sources may be defective (deliberately or not). In this context, the collective information gathered by the system is a progressive (non linear) aggregation of information collected individually by each agent. Therefore, each agent has direct information (collected by itself) and indirect information (obtained through communication with other agents). System coherence is defined by compatibility of collectively collected information about the explored environment with actual information of the environment. System resilience is defined by the capacity to maintain information coherence, despite the existence and increase of faulty agents within the system. In this context, we propose a new trust-based mechanism to detect defective agents and a self-organizational approach to act as a guide in communication and limit the dissemination of deceitful information in the system, thus reducing its impact on the process of collective information gathering.

TrustSets: using trust to detect deceitful agents in a distributed information collecting system

This paper addresses the issue of maintaining information coherence and its robustness in a multi-agent system, that collectively gathers information from distributed sources and where some sources may be defective (deliberately or not). In this context, the collective information gathered by the system is a progressive (non linear) aggregation of information collected individually by each agent. Therefore, each agent has direct information (collected by itself) and indirect information (obtained through communication with other agents). System coherence is defined by compatibility of collected information about the explored environment with actual information of the environment. System resilience is defined by the capability to maintain information coherence, despite the existence and increase of faulty agents within the system. In this context, we propose a new trust-based mechanism to detect defective agents and limit the dissemination of deceitful information in the system, thus reducing its impact on the process of collective information gathering.

A communication model of distributed information sources bacteria colonies inspired

The implementation of communication organizational strategies constitutes an essential performance factor. Nowadays, the organization becomes companies competitiveness element (organizational structures), networks, knowledge and competences management, and cooperation. This, to be better reactive to ensure the competing character, to support better new information technologies, concerning the data exchange inside as outside an organization. The information systems specification gives a partial description of the organization, which integrated with other descriptions is regarded as being the organization model. Using the abstraction level of an information system (information source) was proven to be not sufficient to face the conflicts confronted by the organizations. These conflicts are the improvement and the change with an aim of adapting constantly to the environment new requirements. These latter are essential to support the dynamic character which tends to characterize the current organizations and which is often nature taken. In order to implement this dynamism, we took as a starting point the biological sciences and more particularly the bacteria colonies. This paper presents a correspondence model between a communication system of distributed information sources and a bacteria colony

The Web and Complex Adaptive Systems

The Web continues to grow at a phenomenal rate and the amount of information on the Web is overwhelming. Finding the relevant information remains a big challenge. Due to its wide distribution, its openness and high dynamics, the WWW is a complex system, for which we have to imagine mechanisms of content maintaining, filtering and organizing that are able to deal with its evolving, dynamics and distribution. Integrating mechanisms of self-organization of the Web content is an attractive perspective, to match with these requirements. This paper explores the Web from a complex adaptive system (CAS) perspective. It reviews some characteristic behaviours of CAS and shows how the Web exhibits similar behaviours. We illustrate with a model for Web content organization adopting the CAS vision and using the multi-agent paradigm

Dynamic Multi-agent Architecture Using Conversational Role Delegation

This paper discusses the notions of dynamic composition and dynamic architectures, in the context of conversational multi-agents systems, as well as distributed component oriented or object based systems. The directory service or facilitator agent paradigm, commonly used for building architectures exhibiting these properties, is examined and discussed. It is then compared with a proposed alternative paradigm, based on dynamic conversational role delegation. It is shown that the directory service paradigm, among other weaknesses, exposes the system to synchronization problems when complex protocols are used or concurrent access to the directory are involved, and is not transparent. The role delegation paradigm, on the other hand, presents significant advantages, including a better synchronization with ongoing conversations, and allows transparent encapsulation of the compositional behavior. A working prototype, focused on electronic auction and on-the-fly protocol adaptation, through adaptation proxies, is presented to demonstrate the feasibility of the approach.

Towards a Self Organizing Protocol for a Multi Agents System (MASSOP)

The interaction between agents is more than one simple messages exchange: one of the interaction aspects shows a conversation based on a shared and officially agreed messages exchange. The conversations between agents in the multi agents systems (MAS) are often structured according to typical diagrams called interaction protocols. The interaction protocols aspects differ according to the type of the agents.