Abstract:For Web services, a typical Internetware, a new Web service composition model is given: Requirement driven active Internetware entities aggregating from the aspects of active service, requirement driven and automated aggregating. In this model, service Agents discover requirement actively and aggregate around the requirement automatically. The Agent group aggregated for a given requirement becomes an effective multi-Agent system through a process of mechanism design, negotiation, and collaboration. For making Agents have the ability to discover and understand requirements, a function ontology has been created, which includes function descriptions and function decomposition modes in special domain. For the service Agents collaboration, requirement driven automated mechanism design is put forward, and a collaboration model named barycenter model based on justice principle is also constructed. At last a specification for the final multi-Agent system is given.

Abstract:For the uncertainty and incompleteness in the behavior of Internetware, a negotiation-enabled approach to modeling and verification of software architectural behavior is proposed in this paper. In the modeling, this approach takes the notations of UML sequence diagram and extend the model with new elements to support the uncertainty and incompleteness. In the verification, the model checker Spin is employed for checking behavior models. In addition, a negotiation-enabled solution is proposed for the verification with uncertain and incomplete model based on the counter example guided abstract refinement method.

Abstract:As a novel software paradigm evolved by the Internet, Internetware is still faced with many challenges, such as expressing explicit environments, autonomous software entities, self-adaptive run mechanisms, etc. From component perspective, this paper presents EBDI (electronic business document exchange) architecture to describe the components which can autonomously plan themselves at runtime to handle variable environments, and uses dynamic binding relationship to illuminate the self-adaptive and evolutionary components. Throughout formal role model, run status, autonomous run and dynamic evolving run mechanisms for components of Internetware are addressed. As the platform of Internetware, DAgent-Internetware prototype can provide support for Internetware based on DAgent to design, develop, deploy, run and evolve.

Abstract:This paper aims at revealing the essence of volunteer computing from the point of view of formal abstraction. At first, three elements of volunteer computing are analyzed and outlined. It included some concepts of component and computing resource in volunteer computing. One formal model and method concerning volunteers are introduced. Resource roles such as the basic elements of systems are identified in the abstract model, and modeling volunteer systems by basic elements. Relationships among elements and relationship changes are also characterized, based on set theory and operational reduction rules. And take XtremWeb as an example. These elements and relationships are specified in a formal manner. All of the results can help to build a firm foundation for research of formalisms for volunteer computing.

Abstract:Modern component-based systems consist of active components that execute in parallel, which brings great difficulties in verifying correctness. By extending component calculus, a theory concerning refinement of active components is proposed. For interfaces, contracts are introduced which give functional specifications for both public methods and active action in terms of guarded designs. Then, a contract's dynamic behavior is defined by a pair of divergences/failures sets. The refinement relation between contracts is defined as the set inclusion of their divergences/failures sets. The theories applying simulation techniques to assure the refinement relation are proved. By defining the semantics of a component as a mapping from the contract of its required interface to the contract of its provide interface, component refinement can be proved in terms of contract refinement. When the component- based systems are being constructed in a bottom-up manner, the application of the refinement method together with the composition rule can guarantee their correctness.

Abstract:This paper addresses the state-space explosion problem in the context of verifying component composition. It adapts the counterexample guided abstraction refinement (CEGAR) scheme and proposes a compositional verification approach that the verification of component composition is transformed into local abstraction refinement for individual components participating in the composition in order to reduce analysis complexity. The existential quotient based on equivalence relation is employed to compute the abstraction of each component in component composition, and then the abstraction model for the component composition can be built by composing the existential quotients of components. A compositional validation theorem is proposed and proved, so validating if a generated counterexample is valid and refining the abstraction are all carried out component-wise. This approach does not require the construction of a complete state space of the concrete component composition under verification.

Abstract:The uncertain data requirements of Internetware lead to the DP (data pragmatics) uncertainty. And then it is required that the DP operating mechanism has the ability to adapt to the uncertain DP, i.e. the corresponding relationships between application objects and database tables can be dynamically created, updated and removed on demand. As current persistence technologies lack of dynamic adaptation of DP, this paper proposes an approach to dynamically operating DP for Internetware, POD (persistence on demand), based on ORM (object/relational mapping). Together with the mainstream ORM framework, a prototype of persistence framework following POD is implemented.

Abstract:This paper proposes a dynamic QoS assessment approach for Internetware with uncertainty reasoning. The salient feature of this approach is that it's based on Bayesian network, and can correctly predict the component's service capability in various combinations of users' QoS requirements, especially to the entities with different service levels. Through online learning, it supports to update the Bayesian network dynamically and improves the accuracy of prediction result. The proposed QoS assessment model has been implemented in the developed Service Coordination Bus (Once-ESB). The experimental results show that it is effective.

Abstract:This paper considers the formal analysis and verification methods for the environmental resource adaptability of component-based Interneware. Firstly, the resource interface automata is used to model the behaviors of component interfaces which contain the information of dynamical resource utilization, and the resource interface automaton networks are constructed to describe the compositional behaviors of the system. At the same time, the UML sequence diagrams are used to model the specifications of specified behaviors in the compositional system. Then, two typical problems are proposed and analyzed formally, one of them is to check whether all behaviors of a system are satisfied within the specified resource constraints, and the other is the verification of whether the specified behaviors are satisfied when the resources have been changed. Based on analyzing the compatible state space of the resource interface automata networks, a corresponding reachability graph is constructed, and finally several algorithms are developed for the above problems.

Abstract:A method is proposed in this paper for resolving dynamic service evolving based on OSGi. First, use indirect method for updating service definition based-on OSGi. The method can make dynamic evolving transparent. Then, divide service definition into implementation and data, which makes fields in service instance consistent and evolvable. The adding/deleting service during evolving is also discussed. A project is implemented, which can direct how to design, execute and evolve updatable service. The methods mentioned in the paper may be helpful to evolving components, service and object-oriented software.

Abstract:This paper proposes a domain based adaptive replica selecting model named DARSM (domain based adaptive replica selection model), in which component replicas are organized into strong consistency domain and weak consistency domain, and a schema based on consistency window is utilized to synchronize states between theses domains. Accordingly, a partition-balanced based adaptive replica selection algorithm PWARS (partition- weighted based adaptive replica selection) could be built on dynamic performance metric information to select the appropriate replica set that satisfies specific QoS constraints. A consistency window adaptive reconfiguration algorithm CWAR (consistency window adaptive reconfiguration) is presented to adapt to the dynamic change of consistency constraints. In this algorithm, a probability model built on the base of current consistency constraints distribution is used to dynamically adjust the configuration of consistency window. As a result, the inconsistency of each replica is controlled adaptively. This approach has been implemented in OnceAS, and experimental results demonstrate that it can effectively enhance the performance of replica selection.

Abstract:This paper presents a service flow describing language XPL (extended-calling process language) which mainly focuses on value-added service in telecom field, and the supporting system of this language. XPL has the ability to describe both calling and digital services. This language is highly abstract, easily used and fast in developing service. Due to the base of SOA (services-oriented architecture), the supporting system suits service creation under the condition of net merging.

Abstract:Based on the analysis of 13 well-known available bandwidth systems and the experience in designing, building, and deploying the BNeck system, the fundamental problems with available bandwidth measurement systems are analyzed comprehensively.

Abstract:This paper studies the security of a newly proposed stream cipher structure based on linear feedback shift register, nonlinear feedback shift register and filter Boolean functions. A distinguishing attack on this structure is presented. An example is illustrated to show the effectiveness of this attack. This new attack suggests that this new stream cipher structure has potential security weakness.