Youna Jung

A survey of security issue in multi-agent systems

Multi-agent systems have attracted the attention of researchers because of agents’ automatic, pro-active, and dynamic problem solving behaviors. Consequently, there has been a rapid development in agent technology which has enabled us to provide or receive useful and convenient services in a variety of areas such as banking, transportation, e-business, and healthcare. In many of these services, it is, however, necessary that security is guaranteed. Unless we guarantee the security services based on agent-based systems, these services will face significant deployment problems. In this paper, we survey existing work related to security in multi-agent systems, especially focused on access control and trust/reputation, and then present our analyses. We also present existing problems and discuss future research challenges.

Multi-agent based community computing system development with the model driven architecture

Ubiquitous system can be considered as a system, in which many kinds of component are connected by networks and the components cooperate with each other for achieving some goals. To develop a ubiquitous system, several researches have used multi-agent models. Even thought current multi-agent models provide many benefits with ubiquitous system developments, they are not enough to develop ubiquitous systems. In this paper, we address the ubiquitous system which solves its problems with cooperative organization consisting of several heterogeneous computing components. We call such a ubiquitous system as a community computing system. In the community computing system, some goals are given to be achieved by the cooperative organization. In this paper, we propose a high-level abstraction model of multi-agent based community computing system. In addition, we propose the development process of the community computing system using MDA(Model Driven Architecture) approach.

Community computing model supporting community situation based strict cooperation and conflict resolution

Community computing is a new computing environment where ubiquitous services are provided by cooperation between existing smart object. In these days, it is studied by many researchers but works on community computing are still at an early phase. To design and describe cooperation effectively, in this paper, we propose the community situation based cooperation model. In addition, we introduce conflict resolution scheme for community computing. Consequently, we propose the community computing model supporting the community situation based cooperation and conflicts resolution. Case studies are also tried to examine the proposed community computing model.

Context-Based cooperation architecture for ubiquitous environment

Context-awareness which provides relevant information and services to situation using context is an important issue to solve problems in ubiquitous environment. In addition, many problems in ubiquitous environment are solved by interaction between computational elements rather than by performing individual actions. Therefore, it needs to approach context-awareness from in a cooperative point of view. In this paper, we discuss about context model for cooperation system in ubiquitous environment and describe context ontology focused on interaction process with general context. Moreover, we propose cooperation architecture based on context ontology supporting ontological processes. This architecture introduces community as an organization of elements solving common problem and provides context-aware mechanism within community.

RiBAC: Role Interaction Based Access Control Model for Community Computing

Community computing is an agent-based development paradigm for ubiquitous computing systems. In a community computing system, ubiquitous services are provided by cooperation among agents. While agents cooperate, they interact with each other continuously to access data of other agents and/or to execute other agent’s actions. However, in cases of security-critical ubiquitous services such as medical or military services, an access control mechanism is necessary to prevent unauthorized access to critical data or action. In this paper, we propose a family of Role interaction Based Access Control (RiBAC) models for Community Computing, by extending the existing RBAC model to consider role interactions. As a basic model, we propose the core RiBAC model. For the convenience of management and to provide more fine-grained access control, we propose Hierarchical RiBAC (H-RiBAC), Constrained RiBAC (C-RiBAC), and Constrained Hierarchical RiBAC (CH-RiBAC) models. Finally, we extend the existing community computing framework to accommodate the specification and enforcement of RiBAC policies.

Sports Image Classification through Bayesian Classifier

Most documents on the web today contain image as well as text data. So far, classification of images has been dependent on the annotation. For the more efficient and accurate classification, not only textual data but also image contents should be considered. In this paper, we propose a novel method for classifying specific image data; sports images. The proposed method is based on the Bayesian framework and employs four important color features to exploit the properties of sports images.

HIPAA-Compliant Privacy Policy Language for e-Health Applications

Many e-health applications collect patients health data and track how they are used by patients to enable and validate their effectiveness. Although e-health applications allow people to access healthcare services in easy and convenient way at the reduced cost, the lack of reliable and effective methods of privacy protection makes people hesitate to use e-health applications, and in turn, it becomes the biggest obstacle to the growth of e-Health applications. To overcome the drawback, in this paper, we first address the lack of consideration of health-related data on existing privacy policy languages and propose the HIPAA profile for existing languages, which contains the Health data schema and extensions to HIPAA-friendly policy languages. By using the HIPAA profile, e-health providers are able to specify HIPAA-compliant privacy policies and patients can express their privacy preferences on not only general usage and user data but also health-related data in detail. For better understanding, we present example policies for e-health applications and patients using the proposed profile.

DRiBAC: Fine-grained dynamic role interaction access control using ontology

Multiagent systems are characterized by enriched interactions among agents, which have dynamic and autonomous behavior, towards achieving some common goals. Such interactions involve accessing an agents resources and functionalities by other agents. It is critical that such interactions are secure and agents engage in only authorized interactions based on their roles. In this paper, we propose a fine-grained Dynamic Role Interaction Access Control (DRiBAC) model to support exclusive authorization for agents that need to engage in interactions with other agents by dynamic assignments of roles and permissions and their activations. We extend an earlier proposed RiBAC model with the notion of role interaction and interaction assignment and context-aware constraints. To capture the model and its context, and to support semantic reasoning of DRiBAC policies, we propose DRiBAC ontology and illustrate its use on an example online tutoring system.

A flexible privilege management scheme for role graph model

Since the role-based access control was introduced in the early 1970s, it has been considered as one of the promising access control methods. The role graph model was suggested as a reference model for the role-based access control. However, its privilege management is too strict to be applied to various applications. In this paper, therefore, we propose a flexible privilege management scheme based on the refinement of privileges in the role graph model, and show its effectiveness through several scenarios. We expect that this scheme will make the role graph model more powerful and applicable.