Connecting Smart Things through Web Services Orchestrations

User preference-based automatic orchestration of web services using a multi-agent

Semantic Web services is considered as the concept bringing the web to its full potential by combining the best features of web services, agent technology, grid and the Semantic web. In this paper we present a semantic Web Services platform based on software agent (JASW), which introduces Semantic web and software agent and takes the automated discovery, selection, orchestration and invocation of Web services as application background. In the platform, we adopt Semantic web to accurately describe Web services, and use software agent to implement discovery, selection, and orchestration of Web services.

Softwareengineersareincreasinglyadoptingserviceorientedar-chitectures (SOAs) for the automation of business processes andthe integration of IT systems, both within and across organisa-tional boundaries. These service oriented architectures frequentlyrely on web service standards, such as the Web Service Descrip-tion Language (WSDL) [5] and the Simple Object Access Protocol(SOAP) [10] for the implementation of service invocations acrossmachine boundaries.The combination of several web services into a more complexweb service is a crucial building block for service oriented archi-tectures. Peltz refers to such compositions that integrate the in-vocation of two or more services into a more complex executableworkflow as web service orchestration and contrasts this with webservice choreography, which tracks message exchanges betweendifferent autonomous domains [13]. Web service orchestration isappealing as it facilitates compositionality and reuse of the compo-nents that implement these services without necessarily having todeploy these services locally.Web service orchestration is supported by the Business ProcessExecution Language for Web Services (BPEL) [1]. BPEL emergedthrough consolidation of earlier work on IBM’s Web Service FlowLanguage (WSFL) [11] and XLANG [14] developed by Microsoft.BPELwas proposedas astandardby Microsoft, IBM,Siebel, BEA

Interacting with the Web of Things

Service Oriented Architecture (SOA) is an emerging computing model that aims to build new software, by assembling independent and loosely coupled services. This composition can be described from both a local or a global perspective by respective orchestration or choreography. In fact, the main focus of this paper is to validate a web service orchestration through the verification of properties. This verification must take into account both generic and specific properties. The generic properties can be checked for any invoked web services when the specific properties are different interdependence relationships between activities within an orchestration process. These properties cannot be directly verified on the process, so, we have to use formal techniques. Doing so, we will present, in this paper, our formal approach to validate a web service orchestration. The paper adopts WS-BPEL 2.0 as the language to describe the web service orchestration and uses the SPIN model-checker for the verification engine. The WS-BPEL specification is translated into Promela code which is the input language for SPIN model-checker, in order to check generic and specific properties expressed with LTL (Linear Temporal Logic). A tool named Bpel VT (BPEL Verification Tool) is developed to support the proposed approach. It provides the WS-BPEL manager, the automated process translation of WS-BPEL to Promela code and model-checking views.

S2O: A smart objects orchestrator framework based on the web of things

Spatial Data Infrastructures (SDI) have been widely accepted to exchange geospatial data among organizations. Today SDIs main focus lies on the provision of geospatial data in the form of distributed spatial web services, the retrieval through catalogues, and visualization in the form of Web Map Services (WMS). The hypothesis presented in this paper takes SDI's one step further by providing a method to process geodata in an Open Geospatial Consortium (OGC) compliant way into information. Two case studies present the potential of standardized geoprocessing services. In addition, this paper addresses the problem of service chaining by providing a system architecture to implement complex geoprocessing models and workflows based on web services using Web Service Orchestration (WSO). The proposed methods utilize spatial standards provided by OGC, the International Organization for Standardization (ISO) and ‘mainstream IT’ standards provided by the World Wide Web Consortium (W3C) and the Organization for the Advancement of Structured Information Standards (OASIS) to establish a generic web service architecture for providing common geoprocessing capabilities (e.g. spatial algorithms, map algebra, etc.) for usage in SDIs.

The key concept of the Internet of Things (IoT) is linking physical smart things to the Internet to make them active participants on the Internet. The Web of Things (WoT) uses the World Wide Web platform and its associated technologies as a framework to realize IoT. Inspired by WoT, we propose a new paradigm, the Virtual Environment of Things (VEoT), to integrate real-world smart things and virtual-world avatars/objects in a computer generated virtual environment so that entities in either worlds can interact with one another in a real-time manner. To prove the VEoT concept, we design a hierarchical smart gateway, REX (Resources Exchange), to embody smart things as Restful resources that can be combined with networked virtual environments (NVEs) to realize the integration and the interaction of the virtual environments and the real world. In addition, we implement a VEoT-based NVE, called X-Campus, for guiding visitors to navigate a building of National Central University to verify the feasibility of VEoT. This implementation shows the VEoT framework works properly.

Service-Oriented Architectures (SOA) benefit from business processes (BP), which orchestrate web services (WS) and human actors in cross organizational environments. In this setting, handling the security and privacy issues while exchanging and processing personal data is essential. This lacks for secure business processes management. To achieve this, we represent security constraints descriptively by annotating process models, aiming to enforce these constraints by a secure business process management system (BPMS).To assist the process modeler in annotating process models, we introduce in this paper a tool which provides semantic interoperability during process design. By enforcing a shared conceptualization (ontology) of the security and privacy domains with an ontology base grounded in natural language this tool called knowledge annotator is able to make annotation recommendations according to knowledge stored in a knowledge base. The annotator is validated in an employability use case scenario.

Policy-based management provides Web of Things (WoT) system with the ability to describe its requirements and functionality, so that desired service goals are achieved. This requires WoT system provisioning smart things which can work under the guidance of policies. However, policy makers with less awareness of specific safety constraints of smart things may create harmful policies, which make smart things work in unexpected situations and cause safety issues. From the view of smart things, the notion of safety issues is two-fold: First, devices themselves work in an unsound and unsecure state, second, devices are influenced by other devices with same or contradict function. We identify these safety issues as device-centric modality conflicts and interest conflicts, and then define a specific conflict detection approach for these conflicts. In this paper, we demonstrate the use of the conflict detection approach to detect device-centric conflicts in two cases. Finally, we conduct three experiments to evaluate the accuracy and time performance of the detection approach.

In recent years, many Web service composition languages have been proposed. Web service choreography describes collaboration protocols of cooperating Web service participants from a global view. Web service orchestration describes collaboration of the Web services in predefined patterns based on local decision about their interactions with one another at the message/execution level. In this work, we present model-based methods to close the gap between the two views. Building on the strength of model checking techniques, Web service choreography and orchestration are verified against temporal properties or against each other (to show that they are consistent). Specialized optimization techniques are developed to handle large Web service models. Furthermore, we propose a method to mechanically synthesize a prototype Web service orchestration from choreography, by repairing the choreography if necessary and projecting relevant behaviors to each service provider.

Education and training is an important part of the career and is one of the welfares for an employee supplied by enterprise. Various knowledge base and test questions are usually developed and maintained in the departments or divisions to aid educating and training. These databases may be different at data structure, style, specialized subject or difficult level. To make the education and training stardardized, and to unite and integrate the databases at different departments, we design a framework for education resources management in an enterprise, which is based on web service orchestration. In this framework, the physical details and implementation details of the scattered databases are transparent to the education executive, which is owed to the web service standard protocol stack and related regulations. The education executive needs to define the education goal and process, and to define an instance of education project and the rules of assembling information. The framework is verified to be effective after deployed to accomplish education, training and examination.

Although information and Internet technology developed rapidly, how to realize flexible integration of enterprise application, and how to realize coordination of the heterogeneous information system and automation of the business process, have been core issues that need to be further researched. Application of Web Services and WS-BPEL can solve this problem. By using Web Services, which is platform-independent and loosely coupled, business process can be adapted to rapidly changing environment. On the other hand, BPM combination of services for process planning and management can further improve business efficiency and lower development cost. In this paper, based on the web services and WS-BPEL, utilizing a typical commercial model, the web services of business process are developed, and the method of using WS-BPEL for process planning is explored. At the same time, web services orchestration is fulfilled through the WS-BPEL, commercial model of process automation instance is established. In the end, business process automation is implemented and tested accordingly.

Web Services are becoming the prominent paradigm for distributed computing and electronic businesses. This makes natural the extension of the concepts at the base of the workflow management systems to coordinate network services supplied by many organisations, in order to develop and realise B2B architectures. In this context, the Web Services technology provides the base to make complex business processes through the composition of Web Services (Web Services orchestration and choreography). This paper introduces the current state of the research in this area, and, with reference to the most used Web Service orchestration language (BPEL4WS), introduces a methodology in order to find, through the analysis of different workflows, parts of workflow characterised by Web Services which interact according to a determined model of interaction, in order to obtain a common target. Moreover, we present the ARCOS (Automatic Reusable COmponent Search) Tool which implements the proposed methodology, and, we show its application to a realistic case study.

Verification techniques like model checking, preorder checking and equivalence checking are shown to be relevant to web service orchestration. The Concurrency Workbench of the New Century (CWB) is a verification tool that supports these verification techniques. By means of the Process Algebra Compiler (PAC), the CWB is modified to support the BPE-calculus. The BPE-calculus is a small language, based on BPEL4WS, to express web service orchestration. Both the syntax and the semantics of the BPE-calculus are formally defined. These are subsequently used as input for the PAC. As output, the PAC produces modules that are incorporated into the CWB so that it supports the BPE-calculus and, hence, provides a verification tool for web service orchestration.