Peng Pan

Ontology based hybrid access control for automatic interoperation

Semantic interoperation and service sharing have been accepted as efficient means to facilitate collaboration among heterogonous system applications. However, extensibility and complexity are still crucial problems in supporting multi-level automatic collaborations across dynamically changed domains. In this paper, we propose the ontology based hybrid access control model. It introduces the concept of Industry Coalition, which defines the common ontology and servers as the portal of an application domain for public. By mapping local authorizations to the common ontology, an enterprise can efficiently tackle the problems of automatic interoperation across heterogonous systems in the Coalition, as well as of the general requests from dynamically changed exterior collaborators not belonging to the Coalition. Several algorithms are also proposed to generate authorization mappings and maintain security constraints consistent. To illustrate our model, an example of property right exchange is given and experiment results are discussed.

A Deep Web Data Integration Model for Pervasive Computing

Pervasive computing demands to integrate all kinds of data, but with the rapid development of Web, there are more and more Web databases behind the query forms. It becomes imperative to provide an integrated query engine over Web databases under pervasive computing environments. In this paper, using house domain of Chinese environment as an example, we propose a more effective technique to perform this task. Our frame is called DWDE. Using Domain Ontology the process of Deep Web data integration is simplified, which only includes three modules, that is Query Interfaces Integration, Web Database Selection and Data Merger. It can get data rapidly and accurately from web databases. It adds three modules for pervasive computing, Interest Degree Manage, Demands Acquirement and Data Presentation. Using these modules, DWDE can combine a Deep Web data integration system into pervasive computing environments seamlessly, and provide better services to the users.

User Interest Learning in Pervasive Computing Environment

The advent of pervasive computing puts forward a new challenge for individual information research. With the explosion of information on the Internet, finding information relevant to a users interest can be a time-consuming and tedious task. User interest learning plays an important role in information personalization. In this paper, a learning approach to acquire and update user interest is proposed. The approach firstly models user profile as feature vectors. Then pervasive device captures users implicit feedback based on his/her reading behavior and delivers it to the server. At last, the server infers user interest and updates user profile by adjusting the weights of features to keep track of the dynamic change of user interest. The experiment suggests that the way of implicit feedback in the approach is effective and the precision of the information given to users is encouraging.

An approach for flexible RBAC workflow system

With the fast increase of electronic commerce, more and more enterprises and organizations are facilitating their business processes by workflow. To protect information secure and meet the requirement of frequent business changes over time, the security and flexibility become two of the most important aspects that attract attention both from academy and industry. Many related research work on flexible workflow and secure RBAC model were presented respectively. Unfortunately, the analysis and implementation of enforcing RBAC into Web-based flexible workflow have not been mentioned The intention of this paper is to extend RBAC framework further to flexible workflow to support the security, flexibility and expansibility of organization business. A model and its corresponding mechanism are introduced for establishment, dynamical customization and run-time management of the RBAC workflow. A practical system for Property Right Exchange (PRES) based on this model is implemented.

The top-k skyline query in pervasive computing environments

In pervasive computing environments, more and more applications or platforms based on mobile phone and PDA emerged. People could get what they want from these platforms anywhere. Top-k and skyline query are two methods to satisfy users preferences. In many situations, we need to combine the two querying technologies to satisfy the users preferences, which is called top-k skyline query. Based on a given pervasive computing scenario, we formulate a theoretical model for top-k skyline query, describe an algorithm that proceeds the skyline and top-k query synchronously. It shows better performance in experiment than algorithms proposed in [3].

Top-K Query Answering for Probabilistic Data Integration Systems in Pervasive Computing Environment

In pervasive computing environment, a challenge is how to exchange and share information on heterogeneous devices. The mediated-base approach of data integration provide a uniform view by creating the semantic relationship between sources and mediated schema. Since the manual match is unfeasible, many automatic approaches are developed. The probability of mappings should be considered inevitably during a query proposed on the global schema of mediated process. Since each tuple of the results has different probability, we may adapt Top-K algorithm to get the most approximate k answers. In this paper, based on a given pervasive computing scenario, we formulate a theoretical model for data integration with probability, demonstrate the probabilities for schema mappings and query answering. We also describe a distributed top-k algorithm cooperating with a local top-k algorithm.

Rank queries in probabilistic data integration systems for digital library federation

In digital library federation, a challenge is how to exchange and share information on heterogeneous digital libraries. The mediator-based approach of data integration provide a uniform view by creating the semantic relationship between sources and mediated schema. Since automatic matching produce probabilities, itpsilas necessary to take the probability of mappings into consideration. Further more, for tuplespsila probabilities arise as an additional ranking dimension, both tuple probabilities and scores be factored in the interpretation of top-k queries in probabilistic databases.In this paper, after proposing a architecture of data integration for DLF, we demonstrate the probabilities for the schema mappings and query answerings. Then, having discussed the opt_U-kRank algorithm, we describe the revised_U-kRank algorithm which may improve the efficiency of execution. Finally, based on the experiment results of two U-kRank algorithms, we discuss the effect of probabilities distribution on executions.

An approach for trusted interoperation in a multidomain environment

There are increasing requirements for interoperation among distributed multi-domain systems. The key challenge is how to balance security and collaboration. A novel approach is proposed in this paper to support the trusted interoperation. It introduces the notions of effect scope and life condition into role based access control model to restrict permission to be active only in proper environment. Partial inheritance of role hierarchy is presented to support the finely granular access rights as well as the verification algorithms are proposed to maintain security constraints consistent. As an example, XACML-based platform is provided to combine the existent systems for secure interoperation. Without compromising the collaboration, this approach can effectively enforce a layered security policy and can reduce the complexity of security management.