A Formal Approach to Protocol Interoperability Testing

Porotocol Interoperability testing is an important means to ensure the interconnection and interoperation between protocol products.In this paper,we proposed a formal approach to protocol interoperability testing based on the operational semantics of Concurrent TTCN.We define Concurrent TTCN‘s operational semantics by using Labeled Transition System,and describe the interoperability test execution and test verdict based on Concurrent TTCN.This approach is very helpful for the formation of formal interoperability testing theory and construction of general interoperability testing system.     

A formal method to real-time protocol interoperability testing

Interoperability testing is an important technique to ensure the quality of implementations of network communication protocol. In the next generation Internet protocol, real-time applications should be supported effectively. However, time constraints were not considered in the related studies of protocol interoperability testing, so existing interoperability testing methods are difficult to be applied in real-time protocol interoperability testing. In this paper, a formal method to real-time protocol interoperability testing is proposed. Firstly, a formal model CMpTIOA （communicating multi-port timed input output automata） is defined to specify the system under test （SUT） in real-time protocol interoperability testing; based on this model, timed interoperability relation is then defined. In order to check this relation, a test generation method is presented to generate a parameterized test behavior tree from SUT model; a mechanism of executability pre-determination is also integrated in the test generation method to alleviate state space explosion problem to some extent. The proposed theory and method are then applied in interoperability testing of IPv6 neighbor discovery protocol to show the feasibility of this method.     

An approach to the formal analysis of license interoperability

With recent advances in information and telecommunications technologies, a large range of digital content is distributed over the Internet. Whereas diverse licenses are provided to protect the content legally and have the advantage of offering authors many choices, the obstruction of smooth content distribution may occur if the relationships between licenses are not revealed because of differences between the restrictions imposed by each license. To activate digital content distribution, license interoperability must be revealed. In this paper, we propose a framework for formally examining license interoperability by using many-sorted first-order logic. We formalize five actual licenses and examine their interoperability to prove the effectiveness of our proposed framework. The results show that the framework reveals the relationships between licenses.     

A formal framework for service mashups with dynamic service selection

The service mashup programming paradigm is a blooming faction of service oriented Architecture for developing web applications. A mashup application constructs its functionality by combining data, presentation and functionalities obtained from online services published by service providers such as Google and Amazon. This paradigm significantly facilitates the implementation of application and reduces the workload. But it also makes the application rely on the availability and qualities of the online services which beyond its control in which case the robustness of the system requires more concern. This paper proposes a formal model to specify and analyze the behavior and robustness of service mashups under a certain environment where some services may become unavailable. The specification contains both system specification and environment situation. Refinement theory are employed to specify the correctness of dynamic service selection. The framework realizes the service selection by allowing virtual service requests to be handled by any online service having consistent interface and refined functionality. The framework provides a clear definition of the robustness of mashup systems and proposes several rules as well as approaches to preserve the robustness during the development and maintenance of the system.     

Integrating web service and semantic dialogue model for user models interoperability on the web

Nowadays there is a great number of Web information systems that build a model of the user and adapt their services according to the needs and preferences maintained by the user model (UM). One of the most challenging issues of this scenario is the possibility to enable different systems to cooperate in order to exchange the available information about a user. Our aim is to create rich (and scalable) communication protocols and infrastructures to enable consumers and providers of UM data to interact. Our solution for dealing with such an issue is to exploit Web standards for interoperability (i.e. Semantic Web and Web Services) for implementing simple atomic communication, and a dialogue model for implementing enhanced communication capabilities. In particular, two systems can start a semantics-enhanced Dialogue Game as a form of negotiation to clarify the meaning of the requested concepts when a shared knowledge model does not exist, and to approximate the response when the exact one is not available. We propose a distributed semantic conversation framework based on the Sesame semantic environment for the exchange of user model knowledge on the Web. Systems have to expose their user model data as a Web Service, and to exploit a public dialogue knowledge base to start the dialogue. The main advantage of the approach is to allow systems to deal with difficult situations by starting an appropriate dialogue game instead of stopping the communication as in the traditional “all-or-nothing” Web Service approach. On the basis of a preliminary evaluation, the approach has shown an improvement of the adaptation results provided by the systems we tested.     

A taxonomy of geospatial services for global service discovery and interoperability

Geospatial service taxonomies represent the knowledge about the characteristics of geospatial services from the enterprise, computational, information, engineering, infrastructure, or technology viewpoints. This paper presents a lightweight taxonomy of geospatial services with the aim of promoting the global sharing of and interoperability among geospatial service instances. This taxonomy focuses on the knowledge connected with service interoperability. As a hierarchical taxonomy, it consists of six layers: service category, service type, version, profile, binding and uniform resource name (URN), from the root down to the leaves. Each layer is composed of classification nodes, with each node identifying one classification concept. Each concept, with a concrete semantic meaning, can be used to classify service instances. The application of this classification scheme to the Global Earth Observation System of Systems (GEOSS) Component and Service registry is also introduced. The results of this study may lead to the further development of service taxonomy to thoroughly capture the knowledge about geospatial services. The lessons learned may be useful to others representing and manipulating geoscientific knowledge.     

A formal framework for service modeling and prototyping

Service-oriented Computing is rapidly gaining importance across several application domains due to its capability of composing autonomous and loosely-coupled services. In order to support the engineering of service-oriented software applications, foundational theories, service modeling notations, evaluation techniques fully integrated in a pragmatic software engineering approach are required. This article introduces a framework for modeling and prototyping service-oriented applications. The framework consists of a precise and executable language, SCA-ASM, for model-based design, and of a tool for early and quick design evaluation of service assemblies. The language combines the OASIS/OSOA standard Service Component Architecture (SCA) capability of modeling and assembling heterogeneous service-oriented components in a technology agnostic way, with the rigor of the Abstract State Machine (ASM) formal method able to model notions of service behavior, interactions, orchestration, compensation and context-awareness in an abstract but executable way. The tool is based on existing execution environments for ASM models and SCA applications. An SCA-ASM model of a service-oriented component, possibly not yet implemented in code or available as off-the-shelf, can be (i) simulated and evaluated offline, i.e. in isolation from the other components; or (ii) executed as abstract implementation (or prototype) together with the other components implementations according to the chosen SCA assembly. As proof of concept, a case study taken from EU research projects has been considered to show the functionalities and potentialities of the proposed framework.     

基于接口自动机的BPEL4WS Web服务组合形式化模型

介绍了接口自动机的基本语法,针对目前最主要的一种描述和执行基于工作流模式的Web服务组合的规范——Web服务商业流程执行语言 (business process execution language for Web services,BPEL4WS),定义了接口自动机和BPEL4WS之间的概念映射,并给出了BPEL4WS的基于接口自动机的形式化模型,最后通过一个案例给出了BPEL4WS到接口自动机的映射及验证的方法。     

Cost model based service placement in federated hybrid clouds

As cloud federation allows companies in need of computational resources to use computational resources hosted by different cloud providers, it reduces the cost of IT infrastructure by lowering capital and operational expenses. This is the result of economies of scale and the possibility for organizations to purchase just as much computing and storage resources as needed whenever needed. However, a clear specification of cost savings requires a detailed specification of the costs incurred. Although there are some efforts to define cost models for clouds, the need for a comprehensive cost model, which covers all cost factors and types of clouds, is undeniable. In this paper, we cover this gap by suggesting a cost model for the most general form of a cloud, namely federated hybrid clouds. This type of cloud is composed of a private cloud and a number of interoperable public clouds. The proposed cost model is applied within a cost minimization algorithm for making service placement decisions in clouds. We demonstrate the workings of our cost model and service placement algorithm within a specific cloud scenario. Our results show that the service placement algorithm with the cost model minimizes the spending for computational services.     

A semantic enriched data model for sensor network interoperability

One of the main open issues in the development of applications for sensor network management is the definition of interoperability mechanisms among the several monitoring systems and heterogeneous data. Interesting researches related to integration techniques have taken place, they are primary based on the adoption of sharing data mechanisms. In the last years, the Service-Oriented Architecture (SOA) approach has become predominant in many sensor network projects as it enables the cooperation and interoperability of different sensor platforms at an higher level of abstraction. In this paper we propose a novel architecture for the interoperability of sensor networks, which is based on web services technologies and on a common data model enriched with semantic concepts and annotations. The proposed architecture allows the development of complex decision support system applications by integration of heterogeneous data, accessible through services, according to standard data format and standard protocols.     

A model for the formal definition of programming languages

An operational model which allows the complete formal definition of the full syntax and, particularly, semantics of programming languages is described. Both its syntactic and semantic parts are based on so-called linked-forest manipulation systems which allow the definition of mappings on forests. The idea of “linking” is crucial for the given model, we represent not only abstract programs but also intermediate states of our system (abstract computer) by labelled forests with pointers.     

PKI互操作性的一种新的信任模型

PKI是解决电子商务和电子政务安全的有效途径。针对不同国家和不同组织采用不同的PKI安全政策和实现引发的互操作性问题,提出了一种新的CA环状信任模型——网关型CA来解决PKI的互操作性。     

A theoretical model for the automatic generation of tag clouds

This paper presents a new approach to information retrieval from non-structured attributes in databases, which involves the processing of text attributes. To make retrieval more effective, frequent text sequences are extracted and mathematically represented as intermediate forms which permit a clearer and more precise definition of operations on texts. These intermediate forms appear to users in the form of tag clouds to facilitate content identification, exploration, and querying. In this sense, tag cloud visualization is a simple, user-friendly visual interface to data. This paper proposes a theoretical model for the representation of frequent text sequences and their operations as well as a general procedure for generating tag clouds from text attributes in databases. The tag clouds thus obtained were compared with conventional tag clouds composed of single terms. Our study showed that automatically generated multi-term tag clouds provide better results than mono-term tag clouds.     

A formal security model for microprocessor hardware

The paper introduces a formal security model for a microprocessor hardware system. The model has been developed as part of the evaluation process of the processor product according to ITSEC assurance level E4. Novel aspects of the model are the need for defining integrity and confidentiality objectives on the hardware level without the operating system or application specification and security policy being given, and the utilization of an abstract function and data space. The security model consists of a system model given as a state transition automaton on infinite structures and the formalization of security objectives by means of properties of automaton behaviors. Validity of the security properties is proved. The paper compares the model with published ones and summarizes the lessons learned throughout the modeling process     

A formal model for knowledge-based systems verification

A logico-algebraic model for verification of Knowledge Based Systems, based on Abraham Robinson's meta-algebra, is presented in this article. the set of rules of Knowledge Based System is considered to be the set of axioms of a theory “T”. the model consists of: (i) the collection “P” of all well formed formulas of the language of T, (ii) a subset P₀ of P that has as its elements the axioms of a given logic (bivalued, intuitionistic, or other), plus all the theorems that can be deduced from this logic inside the language of T, (iii) some distinguished subsets of P, to be called m-ideals and m-filters, that depend on T and P₀. Important concepts that are involved in the verification of Knowledge Based Systems are considered, such as forward and backward reasoning consistencies. Appropriate characterizations are obtained by using properties of m-ideals and m-filters. © 1994 John Wiley & Sons, Inc.     

A formal model for module interconnection languages

A model is proposed that formalizes the design of hierarchical module structures. The model is specified by a collection of Z schema type definitions that is invariant across all applications. A particular application is described by specifying the values of generic parameters and adding application-specific declarations and constraints to the schema definitions. As applications, the definitions in the model are used to describe the Conic configuration language and the STILE graphical design and development environment     

A formal semantics for the Taverna 2 workflow model

This paper presents a formal semantics for the Taverna 2 scientific workflow system. Taverna 2 is a successor to Taverna, an open-source workflow system broadly adopted within the e-science community worldwide. The new version improves upon the existing model in two main ways: (i) by adding support for data pipelining, which in turns enables input streams of indefinite length to be processed efficiently; and (ii) by providing new extensibility points that make it possible to add new operators to the workflow model. Consistent with previous work by some of the authors, we use trace semantics to describe the effect of workflow computations, and we show how they can be used to describe the new features in the Taverna 2 model.     

A formal model of explanation

As information systems become more complex, formal methods offer a solution to the increasing problem of ensuring correctness of design and implementation. This paper illustrates the use of mathematical specification to formalise the notion of explanation. This is relevant to any information system which engages in inference. An information system is regarded as a homogeneous function on states of information. An explanation for a conclusion is regarded as a weakening of the theory relating input to output, such that the same conclusion is reached. As an example, the specification is implemented for a simple statistical classifier to assist medical diagnosis.