Web Service Description Language Research Articles

Harmonised information exchange between decentralised food composition database systems

The main aim of the European Food Information Resource (EuroFIR) project is to develop and disseminate a comprehensive, coherent and validated data bank for the distribution of food composition data (FCD). This can only be accomplished by harmonising food description and data documentation and by the use of standardised thesauri. The data bank is implemented through a network of local FCD storages (usually national) under the control and responsibility of the local (national) EuroFIR partner. The implementation of the system based on the EuroFIR specifications is under development. The data interchange happens through the EuroFIR Web Services interface, allowing the partners to implement their system using methods and software suitable for the local computer environment. The implementation uses common international standards, such as Simple Object Access Protocol, Web Service Description Language and Extensible Markup Language (XML). A specifically constructed EuroFIR search facility (eSearch) was designed for end users. The EuroFIR eSearch facility compiles queries using a specifically designed Food Data Query Language and sends a request to those network nodes linked to the EuroFIR Web Services that will most likely have the requested information. The retrieved FCD are compiled into a specifically designed data interchange format (the EuroFIR Food Data Transport Package) in XML, which is sent back to the EuroFIR eSearch facility as the query response. The same request-response operation happens in all the nodes that have been selected in the EuroFIR eSearch facility for a certain task. Finally, the FCD are combined by the EuroFIR eSearch facility and delivered to the food compiler. The implementation of FCD interchange using decentralised computer systems instead of traditional data-centre models has several advantages. First of all, the local partners have more control over their FCD, which will increase commitment and improve quality. Second, a multicentred solution is more economically viable than the creation of a centralised data bank, because of the lack of national political support for multinational systems.

Discovery of semantic Web Services with an enhanced‐Chord‐based P2P network

AbstractCurrently Web Service (WS) systems are based on central registries for publication and discovery. With the growing number and the dynamicity of WS, this centralized approach rapidly becomes inefficient and impractical. Furthermore, existing WS standards such as WS Description Language (WSDL) and Universal Description, Discovery and Integration (UDDI) do not support semantic description which is essential for the automation of several WS‐related functions such as discovery, execution and composition. We propose a system that enables efficient Semantic WSs publication and discovery in a fully decentralized network using peer‐to‐peer technologies. We also propose and evaluate the performances of an enhanced version of Chord protocol that we have called ‘enhanced‐Chord’. Copyright © 2010 John Wiley & Sons, Ltd.

Revising WSDL Documents: Why and How

Although Web service technologies promote reuse, Web Services Description Language (WSDL) documents that are supposed to describe the API that services offer often fail to do so properly. Therefore, finding services, understanding what they do, and reusing them are challenging tasks. The authors describe the most common errors they've found in real WSDL documents, explain how these errors impact service discovery, and present some guidelines for revising them.

Sharing geoscience algorithms in a Web service-oriented environment (GRASS GIS example)

Effective use of the large amounts of geospatial data available for geospatial research and applications is needed. In this paper, the emerging SOAP-based Web service technologies have been used to develop a large number of standard compliant, chainable geospatial Web services, using existing geospatial modules in software systems or specific geoscientific algorithms. A prototype for wrapping legacy software modules or geoscientific algorithms into loosely coupled Web services is proposed from an implementation viewpoint. Module development for Web services adheres to the Open GIS Consortium (OGC) geospatial implementation and the World Wide Web consortium (W3C) standards. The Web service interfaces are designed using Web Services Description Language (WSDL) documents. This paper presents how the granularity of an individual existing geospatial service module used by other geoscientific workflows is decided. A treatment of concurrence processes and clustered deployment of Web services is used to overcome multi-user access and network speed limit problems. This endeavor should allow extensive use of geoscientific algorithms and geospatial data.

Developing an End-to-End Scientific Workflow:

Grid-based simulation usually involves sequences of activities such as resource discovery, job submission, file transfer, analysis and simulation, and data harvesting. We can use service-oriented workflow to automate task coordination without direct human control, where each task and legacy scientific code can be presented as a Web service and thereby simplifying workflow development and maintenance. Because each service is described using Web Service Description Language, workflow manager works only with the WSDL interface rather than specific implementations.

A service based interface for scientific data retrieval

Retrieval of scientific data at large fusion experiments is an important but surprisingly complicated task. There are many different data storage systems that have to be accessed using different software interfaces on varying platforms. With MDS+ a respectable approach towards a more standardised and simplified data access interface was started. However, it has its drawbacks regarding continuously acquired data and provides a whole data storage system rather than only an interface, which is not always demanded. Therefore, a data access interface based on service oriented technologies has been developed aiming for a more standardised and platform independent solution. The contribution will describe the current status of this development. It will explain the interface itself including the WSDL (Web Service Description Language) definition and show currently existing service implementations for the Wendelstein 7-X and the Wendelstein 7-AS data storage systems. Furthermore different possibilities to access the services on the client side will be discussed.

Trends and Issues in Integrating Enterprises and other associated systems using Web Services

A Web service is defined as an autonomous unit of application logic that provides either some business functionality or information to other applications through an Internet connection. Web services are based on a set of XM L standards such as Simple Object Access Protocol (SOAP), Universal Description, Discovery and Integration (UDDI) and Web Services Description Language (WSDL). The notorious success that the application of the Web service technology has achieved in B2B e-Commerce has also lead to consider it as a promising technology for designing and building effective business collaboration in supply chains. The key challenges for enterprises nowadays are, how efficiently to integrate business functions and associated systems using web services. The business process automation has generated the need for integrating the available web services across different systems. To achieve this, a better understanding of current methodologies for service integrations is required. In this paper, we investigate the current trends and issues in integrating businesses and other associated systems using web services.

A Novel Cost Model of XML Serialization

Using XML as a data representation format is a common choice when integrating software systems on different platforms. The serialization of in-memory object instances of a class into corresponding XML documents heavily influences the performance of the XML-based communication, even if we send the XML over HTTP as in the case of SOAP-based XML Web Services, or with asynchronous messaging such as Java Message Service (JMS), or simply saving it into a file. Several studies have been published analyzing the performance impact of XML serialization on different platforms. No models or measurement methodologies have been proposed however, to establish a relationship between the serialization cost of primitive types (e.g. int, double, string), and the serialization cost of composite types. Such a model can be very useful when the type of the XML messages exchanged during the communication are known a priori, recorded in an interface definition, similarly to the Web Services Description Language (WSDL) in case of XML Web Services. This paper introduces a model that is validated with measurements on .NET and Java platform. The opposite direction, deserialization is covered as well. The main mathematical tool used is linear regression, but cases are also shown and explained where linearity is compromised.

ERP and PDM integration technology to support collaborative product development

Enterprises product collaborative development gathers partners distributed in space, time and organisations in order to achieve a common goal. Product Data Management (PDM) and Enterprise Resource Planning (ERP) systems are two important tools to support product data in the product collaborative design and manufacture process. However, they are often used in the enterprise separately. A framework of data integration based on the PDM/ERP system to support data coordination interaction is put forward in the paper. Several kinds of methods and models for data exchange are discussed, which include the seven layers of sandglass transfer exchange, coding data exchange and modularisation data exchange, etc. We also present a data synchronisation algorithm between ERP and PDM system and build a relevant rule. Data integration is realised between SmarTeam and WhutERP by using XML and Web Services Description Language (WSDL) standard. A collaborative product development case of stream turbine body is given in the end.

The "GDSClient" Collecting Tool for Networked Solid Earth Science Data

The data center of our institute distributes solid earth science data obtained by the Ocean Hemisphere Project (OHP) network through the website of Pacific 21. We have developed Java-based software GDSClient, which enables us to collect not only the data of the OHP network but also those distributed from other data centers by means of the web service technology. It is possible to request the data controlling parameters such as data centers, observatories, a data period, and other auxiliary detailed parameters. It is unnecessary to know differences between data centers with preparing a WSDL (Web Services Description Language) file, in which information of user interface is described in XML format. The latest GDSClients are released from the website of Pacific 21.

A conceptual graph approach to semantic similarity computation method for e-service discovery

E-services are services that make themselves available on the web and can be invoked over the internet. These services can be composed together to form new services. With the great growth of the number of services on the web it is indispensable to adopt an effective and efficient way to discover and compose them to meet the users' requirements. However, current web services description languages such as WSDL and OWL-S do not provide semantic support for automatic search and composition of services. In this paper, based on the Conceptual Graph theory, we propose a contextual based conceptual model for automatic search and match for services using two kinds of contextual information – service characteristics and inter-service semantic relations. We explore the theoretical models for inter-service and service characteristics semantic similarity computation to match users' service queries and based on the conceptual model we present an effective service matching algorithm.

BioModels.net Web Services, a free and integrated toolkit for computational modelling software

Exchanging and sharing scientific results are essential for researchers in the field of computational modelling. BioModels.net defines agreed-upon standards for model curation. A fundamental one, MIRIAM (Minimum Information Requested in the Annotation of Models), standardises the annotation and curation process of quantitative models in biology. To support this standard, MIRIAM Resources maintains a set of standard data types for annotating models, and provides services for manipulating these annotations. Furthermore, BioModels.net creates controlled vocabularies, such as SBO (Systems Biology Ontology) which strictly indexes, defines and links terms used in Systems Biology. Finally, BioModels Database provides a free, centralised, publicly accessible database for storing, searching and retrieving curated and annotated computational models. Each resource provides a web interface to submit, search, retrieve and display its data. In addition, the BioModels.net team provides a set of Web Services which allows the community to programmatically access the resources. A user is then able to perform remote queries, such as retrieving a model and resolving all its MIRIAM Annotations, as well as getting the details about the associated SBO terms. These web services use established standards. Communications rely on SOAP (Simple Object Access Protocol) messages and the available queries are described in a WSDL (Web Services Description Language) file. Several libraries are provided in order to simplify the development of client software. BioModels.net Web Services make one step further for the researchers to simulate and understand the entirety of a biological system, by allowing them to retrieve biological models in their own tool, combine queries in workflows and efficiently analyse models.

URBE: Web Service Retrieval Based on Similarity Evaluation

In this work, we present UDDI registry by example (Urbe), a novel approach for Web service retrieval based on the evaluation of similarity between Web service interfaces. Our approach assumes that the Web service interfaces are defined with Web service description language (WSDL) and the algorithm combines the analysis of their structures and the analysis of the terms used inside them. The higher the similarity, the less are the differences among their interfaces. As a consequence, Urbe is useful when we need to find a Web service suitable to replace an existing one that fails. Especially in autonomic systems, this situation is very common since we need to ensure the self-management, the self-configuration, the self-optimization, the self-healing, and the self-protection of the application that is based on the failed Web service. A semantic-oriented variant of the approach is also proposed, where we take advantage of annotations semantically enriching WSDL specifications. Semantic Annotation for WSDL (SAWSDL) is adopted as a language to annotate a WSDL description. The Urbe approach has been implemented in a prototype that extends a universal description, discovery and integration (UDDI) compliant Web service registry.

A Modified Operation Similarity Measure Method Based on WSDL Description

Based on the current Web service description standard WSDL (Web Service Description Language), a Modified Operation Similarity Measure (MOSM) method is proposed. After the data preprocessing, an operation included in a Web service is modeled as an unordered labeled tree and get the similarities measured with other operations by calculating the constrained edit distances in MOSM. First the tree structure of the operation′s XML schema is extracted and transformed so as only the tag nodes are kept; then the constrained edit distances among the generated unordered labeled trees are calculated, which turns the operation similarity measure problem into the unordered labeled tree matching problem. The innovations of this paper mainly are: Using the constrained unordered trees instead of the ordered trees as the model, introducing the asymmetric characteristic into the cost model of the tree edit distance algorithm, and introducing the similarity weight into both the structure matching and the string label matching. In the end of the paper the experiments shows that MOSM can effectively improve the top-k precision, which makes much sense to look for the similar back up operations.

RESTful Web service composition with BPEL for REST

Current Web service technology is evolving towards a simpler approach to define Web service APIs that challenges the assumptions made by existing languages for Web service composition. RESTful Web services introduce a new kind of abstraction, the resource, which does not fit well with the message-oriented paradigm of the Web service description language (WSDL). RESTful Web services are thus hard to compose using the Business Process Execution Language (WS-BPEL), due to its tight coupling to WSDL. The goal of the BPEL for REST extensions presented in this paper is twofold. First, we aim to enable the composition of both RESTful Web services and traditional Web services from within the same process-oriented service composition language. Second, we show how to publish a BPEL process as a RESTful Web service, by exposing selected parts of its execution state using the REST interaction primitives. We include a detailed example on how BPEL for REST can be applied to orchestrate a RESTful e-Commerce scenario and discuss how the proposed extensions affect the architecture of a process execution engine.

Automating the manufacturing process under a web based framework

The rapid evolution of the web has affected the way under which the manufacturing process is practised. In this paper, a web based framework – independent from any specific CAD/CAM software – is proposed, for employing electronic interaction between designers and manufacturers. In this context, designers and manufacturers communicate for the manufacturing of a workpiece, under a platform-independent, easier, faster and more economical way. The proposed framework is implemented as a web service, where the Simple Object Access Protocol (SOAP) is used for the exchange of the necessary machined parts data and the methodologies of UDDI (Universal Description Discovery and Integration) and WSDL (Web Services Description Language) are introduced for providing directories and descriptions information.

A flexible geospatial sensor observation service for diverse sensor data based on Web service

Achieving a flexible and efficient geospatial Sensor Observation Service (SOS) is difficult, given the diversity of sensor networks, the heterogeneity of sensor data storage, and the differing requirements of users. This paper describes development of a service-oriented multi-purpose SOS framework. The goal is to create a single method of access to the data by integrating the sensor observation service with other Open Geospatial Consortium (OGC) services — Catalogue Service for the Web (CSW), Transactional Web Feature Service (WFS-T) and Transactional Web Coverage Service (WCS-T). The framework includes an extensible sensor data adapter, an OGC-compliant geospatial SOS, a geospatial catalogue service, a WFS-T, and a WCS-T for the SOS, and a geospatial sensor client. The extensible sensor data adapter finds, stores, and manages sensor data from live sensors, sensor models, and simulation systems. Abstract factory design patterns are used during design and implementation. A sensor observation service compatible with the SWE is designed, following the OGC “core” and “transaction” specifications. It is implemented using Java servlet technology. It can be easily deployed in any Java servlet container and automatically exposed for discovery using Web Service Description Language (WSDL). Interaction sequences between a Sensor Web data consumer and an SOS, between a producer and an SOS, and between an SOS and a CSW are described in detail. The framework has been successfully demonstrated in application scenarios for EO-1 observations, weather observations, and water height gauge observations.

Semantic web services discovery based on structural ontology matching

In this paper, we present an approach to semantic-based web service discovery and a prototypical tool based on syntactic and structural schema matching. It is based on matching an input ontology, describing a service request, to web services descriptions at the 'syntactic level' through Web Services Description Language (WSDL) or, at the semantic level, through service ontologies described with languages such as Ontology Web Language for Services (OWL-S), Web Services Modelling Ontology (WSMO), Semantic Web Services Framework (SWSF) and Web Services Description Language Semantics (WSDL-S). The different input schemas, WSDL descriptions, Ontology Web Language (OWL) ontologies, OWL-S, WSMO, SWSF and WSDL-S components are represented in a uniform way by means of directed rooted graphs, where nodes represent schema elements, connected by directed links of different types, e.g., for containment and referential relationships. On this uniform internal representation, a number of matching algorithms operate, including structural-based algorithms (Children Matcher, Leaves Matcher, Graph and SubGraph Isomorphism) and syntactical ones (Edit Distance (Levenshtein Distance or LD) and Synonym Matcher (through the WordNet synonyms thesaurus)).

Data Complexity Metrics for XML Web Services

Web services that are based on eXtensible Markup Language (XML) technologies enable integration of diverse IT processes and systems and have been gaining extraordinary acceptance from the basic to the most complicated business and scientific processes. The maintainability is one of the important factors that affect the quality of the Web services that can be seen a kind of software project. The effective management of any type of software projects requires modelling, measurement, and quantification. This study presents a metric for the assessment of the quality of the Web services in terms of its maintainability. For this purpose we proposed a data complexity metric that can be evaluated by analyzing WSDL (Web Service Description Language) documents used for describing Web services.

Web service clustering using text mining techniques

The idea of a decentralised, self-organising service-oriented architecture seems to be more and more plausible than the traditional registry-based ones in view of the success of the web and the reluctance in taking up web service technologies. Automatically clustering Web Service Description Language (WSDL) files on the web into functionally similar homogeneous service groups can be seen as a bootstrapping step for creating a service search engine and, at the same time, reducing the search space for service discovery. This paper proposes techniques to automatically gather, discover and integrate features related to a set of WSDL files and cluster them into naturally occurring service groups. Despite the lack of a common platform for assessing the performance of web service cluster discovery, our initial experiments using real-world WSDL files demonstrated the great potential of the proposed techniques.