Web Service Communication Research Articles

A Transformational Approach to Managing Data Model Evolution of Web Services

The communication of web services is typically organized through APIs, which rely on a common data model shared among system components. Over time, this data model must be changed in order to accommodate new or changing requirements, and the components including the data they are operating on must be migrated. In practice however, not all affected components can be migrated instantly and at the same time. A common approach is to plan data model changes in a backward compatible fashion, which causes serious maintenance problems and is a common cause of technical debt. We propose an alternative solution, using a translation layer serving as a round-trip migration service, responsible for the lossless translation of object-oriented data model instances of different versions. We present a framework which offers a version-aware interface definition language (IDL) for APIs, a typed JavaScript-based language using the IDL definition, and a run-time environment. From a methodological point of view, development is supported by a catalog which comprises a set of typical evolution scenarios along with corresponding round-trip migration strategies. We showcase the applicability of our approach via a case study of a real-world e-commerce web application, and evaluate correctness through automated testing.

A secure approach to monitoring emergency health resources

This proposal presents an optimized, efficient and secure system designed to improve healthcare staff management in emergency situations through a complete tool to classify victims in a emergency situation according the severity of their condition, providing at the same time their location and the best route to reach them. The developed tool consists on a mobile application (assigned to medical and healthcare staff), a web service and Near Field Communication tags (assigned to victims). The mobile application supports secure communication among health staff and implements triage algorithms which result is stored in NFC tags. Apart from this, it helps to indicate which should be the next victim to be treated. The developed web service provides a global view of the emergency status and the current position of victims and staff. Data security is a key objective, overall in health applications; for this reason, tokens are used to protect the triage results before being stored in NFC tags, and the use of IDentity-Based Signcryption provides confidentiality and authentication to communications. Two different signcryption methods are used depending on the communication mode (peer-to-peer or broadcast mode).

Non-local configuration of component interfaces by constraint satisfaction

Service-oriented computing is the paradigm that utilises services as fundamental elements for developing applications. Service composition, where data consistency becomes especially important, is still a key challenge for service-oriented computing. We maintain that there is one aspect of Web service communication on the data conformance side that has so far escaped the researchers attention. Aggregation of networked services gives rise to long pipelines, or quasi-pipeline structures, where there is a profitable form of inheritance called flow inheritance. In its presence, interface reconciliation ceases to be a local procedure, and hence it requires distributed constraint satisfaction of a special kind. We propose a constraint language for this, and present a solver which implements it. In addition, our approach provides a binding between the language and C++, whereby the assignment to the variables found by the solver is automatically translated into a transformation of C++ code. This makes the C++ Web service context compliant without any further communication. Besides, it uniquely permits a very high degree of flexibility of a C++ coded Web service without making public any part of its source code.

Supporting integrated care with a flexible data management framework built upon Linked Data, HL7 FHIR and ontologies.

In this paper we present the methodology and decisions behind an implementation of a telehealth data management framework, aiming to support integrated care services for chronic and multimorbid patients. The framework leverages an OWL ontology, built upon HL7 FHIR resources, to provide storage and representation of semantically enriched EHR data following Linked Data principles. This is presented along with the realization of the persistent storage solution and communication web services that allow the management of EHR data, ensuring the validity and integrity of the exchanged patient data as self-describing ontology instances. The framework concentrates on flexibility and reusability, which is addressed by regarding the aforementioned ontology as a single point of change. This solution has been implemented in the scope of the EU project WELCOME for managing data in a telemonitoring system for patients with COPD and co-morbidities and was also successfully deployed for the INLIFE EU project with minimal effort. The results of the two applications suggest it can be adopted and properly adapted in a series of integrated care scenarios with minimal effort.

An eHealth Platform for the Support of a Brazilian Regional Network of Mental Health Care (eHealth-Interop): Development of an Interoperability Platform for Mental Care Integration.

BackgroundThe electronic exchange of health-related data can support different professionals and services to act in a more coordinated and transparent manner and make the management of health service networks more efficient. Although mental health care is one of the areas that can benefit from a secure health information exchange (HIE), as it usually involves long-term and multiprofessional care, there are few published studies on this topic, particularly in low- and middle-income countries.ObjectiveThe aim of this study was to design, implement, and evaluate an electronic health (eHealth) platform that allows the technical and informational support of a Brazilian regional network of mental health care. This solution was to enable HIE, improve data quality, and identify and monitor patients over time and in different services.MethodsThe proposed platform is based on client-server architecture to be deployed on the Web following a Web services communication model. The interoperability information model was based on international and Brazilian health standards. To test platform usage, we have utilized the case of the mental health care network of the XIII Regional Health Department of the São Paulo state, Brazil. Data were extracted from 5 different sources, involving 26 municipalities, and included national demographic data, data from primary health care, data from requests for psychiatric hospitalizations performed by community services, and data obtained from 2 psychiatric hospitals about hospitalizations. Data quality metrics such as accuracy and completeness were evaluated to test the proposed solution.ResultsThe eHealth-Interop integration platform was designed, developed, and tested. It contains a built-in terminology server and a record linkage module to support patients’ identification and deduplication. The proposed interoperability environment was able to integrate information in the mental health care network case with the support of 5 international and national terminologies. In total, 27,353 records containing demographic and clinical data were integrated into eHealth-Interop. Of these records, 34.91% (9548/27,353) were identified as patients who were present in more than 1 data source with different levels of accuracy and completeness. The data quality analysis was performed on 26 demographic attributes for each integrable patient record, totaling 248,248 comparisons. In general, it was possible to achieve an improvement of 18.40% (45,678/248,248) in completeness and 1.10% (2731/248,248) in syntactic accuracy over the test dataset after integration and deduplication.ConclusionsThe proposed platform established an eHealth solution to fill the gap in the availability and quality of information within a network of health services to improve the continuity of care and the health services management. It has been successfully applied in the context of mental health care and is flexible to be tested in other areas of care.

Automatic categorization of Web service elements

PurposeSemantic categorization of Web services comprises a fundamental requirement for enabling more efficient and accurate search and discovery of services in the semantic Web era. However, to efficiently deal with the growing presence of Web services, more automated mechanisms are required. This paper aims to introduce an automatic Web service categorization mechanism, by exploiting various techniques that aim to increase the overall prediction accuracy.Design/methodology/approachThe paper proposes the use of Error Correcting Output Codes on top of a Logistic Model Trees-based classifier, in conjunction with a data pre-processing technique that reduces the original feature-space dimension without affecting data integrity. The proposed technique is generalized so as to adhere to all Web services with a description file. A semantic matchmaking scheme is also proposed for enabling the semantic annotation of the input and output parameters of each operation.FindingsThe proposed Web service categorization framework was tested with the OWLS-TC v4.0, as well as a synthetic data set with a systematic evaluation procedure that enables comparison with well-known approaches. After conducting exhaustive evaluation experiments, categorization efficiency in terms of accuracy, precision, recall and F-measure was measured. The presented Web service categorization framework outperformed the other benchmark techniques, which comprise different variations of it and also third-party implementations.Originality/valueThe proposed three-level categorization approach is a significant contribution to the Web service community, as it allows the automatic semantic categorization of all functional elements of Web services that are equipped with a service description file.

Flexible Web services integration: a novel personalised social approach

Dynamic composition or integration remains one of the key objectives of Web services technology. This paper aims to propose an innovative approach of dynamic Web services composition based on functional and non-functional attributes and individual preferences. In this approach, social networks of Web services are used to maintain interactions between Web services in order to select and compose Web services that are more tightly related to user’s preferences. We use the concept of Web services community in a social network of Web services to reduce considerably their search space. These communities are created by the direct involvement of Web services providers.

Web Service Composition via Supervisory Control Theory

We present a model for the service composition problem and relate it to the classical problem of supervisory control in discrete event systems. In particular, we show how the orchestrator in the first problem transparently maps to the controller in the second problem. Moreover, the community of web services plays the role of the plant in supervisory control and both formalisms are related using the notion of bisimulation. We also show how modal specifications can be used in both settings.

Analysis of Dynamic Web Services: Towards Efficient Discovery in Cloud

Web services are very dynamic as they can be added, modified and deleted from the repository on the fly. Discovering web services for service composition have special requirements. In the service composition, service requirement is not only to satisfy its functional specification but it also needs to ensure that the selected composing services are compatible with respect to their input/output structure and its associated data types. Web Service community [1] organized the functionally similar services together in a group. But one important drawback of using web service community in the service composition is that it requires further analysis of the discovered service communities for selecting appropriate service which can be composed based on its input/output structure and data types. This paper proposes data structures, which can be used to create web service family [2] by filtering not only on the basis of functionality but also on the basis of its input/output structure, which are required for composing services with one another. In order to speed up the web service family creation process, the creation of web service family is divided in two phases. The first phase of the proposed approach introduces a novel concept of business family and dynamic business web service (DBWS) tree, which are used to organize all web services in the tree structure on the basis of their business context and input/output structure. In the second phase, the concept of DBWS tree is used further to create the web service families. The DBWS resembles the classification and organization of businesses in NAICS. The DBWS tree can be used very efficiently for creating web service families, which in turn can be used for selecting service efficiently in service composition.

Engineering web maps with gradual content zoom based on streaming vector data

Vario-scale data structures have been designed to support gradual content zoom and the progressive transfer of vector data, for use with arbitrary map scales. The focus to date has been on the server side, especially on how to convert geographic data into the proposed vario-scale structures by means of automated generalisation. This paper contributes to the ongoing vario-scale research by focusing on the client side and communication, particularly on how this works in a web-services setting. It is claimed that these functionalities are urgently needed, as many web-based applications, both desktop and mobile, require gradual content zoom, progressive transfer and a high performance level. The web-client prototypes developed in this paper make it possible to assess the behaviour of vario-scale data and to determine how users will actually see the interactions. Several different options of web-services communication architectures are possible in a vario-scale setting. These options are analysed and tested with various web-client prototypes, with respect to functionality, ease of implementation and performance (amount of transmitted data and response times). We show that the vario-scale data structure can fit in with current web-based architectures and efforts to standardise map distribution on the internet. However, to maximise the benefits of vario-scale data, a client needs to be aware of this structure. When a client needs a map to be refined (by means of a gradual content zoom operation), only the ‘missing’ data will be requested. This data will be sent incrementally to the client from a server. In this way, the amount of data transferred at one time is reduced, shortening the transmission time. In addition to these conceptual architecture aspects, there are many implementation and tooling design decisions at play. These will also be elaborated on in this paper. Based on the experiments conducted, we conclude that the vario-scale approach indeed supports gradual content zoom and the progressive web transfer of vector data. This is a big step forward in making vector data at arbitrary map scales available to larger user groups.

Web services communities engineering based on user interaction patterns

In today's collaborative environments such as bioinformatics and healthcare, the access to the increasing number of distributed web services constitutes an important step towards enhancing decision support systems. In this context, the concept of community has been proposed to collect web services related to the same field of interest and to publish the features offered by web services. Indeed, the community infrastructure contributes to improving the availability of web services through providing a centralised access to distributed web services. However, many events may occur in the web services communities' environment and should be considered in the web services communities' management. In this paper, we propose a user-interaction-based solution to deal with the web services communities' management problem. The proposed method tackles how web services community can be reengineered based on the user interaction patterns. It is intended to minimise the gap between the user's expectations when visiting and using a web services community as well as the designers point of view used for modelling the community.

Secured Web Service Communication using Attribute based Encryption and Outsource Decryption with Trusted Certificate Authorities (ABE-TCA)

Web services are one of the most aspired technologies in IT industry and more companies are adopting concepts and strategies used in web services for their businesses. User‘s set of attributes paves way for encryption and decryption of data by employing impregnable Attribute Based Encryption (ABE) for defended web service communication, which intensifies its privacy and security. In the existing ABE scheme, decryption involves an expensive process and increase the complexity of the access policy. To overcome the decryption overhead, outsourced decryption is used to authenticate the untrusted servers. The transformation key is responsible for reducing the decryption overhead by translating the complex ciphertext into simple ciphertext based on the user‘s attributes, and the overhead for the conversion of ciphertext to plaintext is acceptably minimal. Kerberos is incorporated to generate a ticket granting service that is used to verify authentication database and after verification of both parties, replies to the requested user for authentication. Furthermore to secure outsourcing agents, Certificate Authority is used to segregate unauthorized users. During data transmission integrity of the data can be verified by hashing algorithms.

Semantically structured service community discovery: based on relationship and functionality

As a key enabler to achieve the full potential of service computing, service community discovery is employed to support web service intelligent application effectively. The proposed framework applies a semantically structured approach to the web service community modelling for service community discovery based on probabilistic graphical model and probabilistic topic model. The approach to the problem is to identify web services of a service community based on both the semantics of the functional properties of web services and the graph structure of the inherent semantic association, dependency among services, which not only leverages the semantic functionality property but also exploits the semantic association relationship between services and operations. The experimental results and analysis shows that the proposed approach is efficient, feasible and practical. The result of the present work implied that the service community can be discovered by the approach and also has the full semantic interpretation.

Semantically structured service community discovery: based on relationship and functionality

As a key enabler to achieve the full potential of service computing, service community discovery is employed to support web service intelligent application effectively. The proposed framework applies a semantically structured approach to the web service community modelling for service community discovery based on probabilistic graphical model and probabilistic topic model. The approach to the problem is to identify web services of a service community based on both the semantics of the functional properties of web services and the graph structure of the inherent semantic association, dependency among services, which not only leverages the semantic functionality property but also exploits the semantic association relationship between services and operations. The experimental results and analysis shows that the proposed approach is efficient, feasible and practical. The result of the present work implied that the service community can be discovered by the approach and also has the full semantic interpretation.

A new approach for enhancing managing and querying Web services communities: health care case study

Collaborative environments in recent years, such as bioinformatics and health care, have seen an increasing interest in Web services communities. The new concept was proposed and widely accepted as a distributed paradigm over the Internet, and has been used widely even in collaborative fixture design and manufacture. Indeed, the community infrastructure contributes to improving the availability of Web services through providing a centralized access to distributed Web services. However, the organization into communities raises many challenges related to communities’ management and querying. In order to cover the mentioned aspects, we propose in this work, an approach which offers a user-interaction-based solution to deal with the services communities’ management problem. The proposed method tackles how Web services community can be re-engineered based on the user-interaction patterns. It is intended to minimize the gap between the user’s expectations when visiting and using a Web services community as well as the designers’ point of view used for modeling the community. Then, we enhance the querying process of the Web services communities. The proposed solution is based on endowing the community with a semantic cache. We show how the health care Web services community’s members can considerably take advantage of the semantic cache while processing a query.

Web services composition: Complexity and models

A web service is a modular and self-described application callable with standard web technologies. A workflow describes how to combine the functionalities of different web services in order to create a new value added functionality resulting in composite web service. QoS-aware web service composition means to select a composite web service that maximizes a QoS objective function while satisfying several QoS constraints (e.g. price or duration). The workflow-based QoS-aware web service composition problem has received a lot of interest, mainly in web service community. This general problem is NP-hard since it is equivalent to the multidimensional multiple choice knapsack problem (MMKP). In this article, the theoretical complexity is analysed more precisely in regard to the property of the workflow structuring the composition. For some classes of workflows and some QoS models, the composition problem can be solved in polynomial time (since the workflow is a series–parallel directed graph). Otherwise, when there exist one or several QoS constraints to verify, the composition problem becomes NP-hard. In this case, we propose a new mixed integer linear program to represent the problem with a polynomial number of variables and constraints. Then, using CPLEX, we present some experimental results showing that our proposed model is able to solve big size instances.

A Study on Detection Techniques of XML Rewriting Attacks in Web Services

Making Web Services secure means making SOAP messages secure and keeping them secure wherever they go. Several security standards of Web Service Security (WS-Security), such as XML Digital Signature, are used to secure SOAP messages exchange in Web Service environment. However, the content of a SOAP message, protected with XML Digital Signature, can be changed without invalidating the signature. In this paper, we present a study on detection techniques of XML Rewriting attacks in Web Services. We first explore the XML Rewriting Attack that can take place in Web Service communication. We further investigate detection techniques and describe their limitations. Finally, we discuss general countermeasures for prevention and mitigation of XML Rewriting attacks.

A GRASP × ELS approach for the job-shop with a web service paradigm packaging

The Job-Shop Scheduling Problem (JSSP) is well known for its complexity as an NP-hard disjunctive scheduling problem. The problem addressed in this paper is JSSPs with an objective of minimizing makespan while satisfying a number of hard constraints. An efficient GRASP×ELS approach is introduced for solving this problem. The efficiency is evaluated using the widely known 40 Laurence’s instances which encompass medium and large scale instances. The computational results prove that the proposed method competes with the best published methods in both quality of results and computational time. Recently, Web services have generated great interest in researchers. Such application architecture is based on the client–server model using existing Internet protocols and open standards. It provides new approaches to optimization methods. The proposed GRASP×ELS is packaged into a Web Service (WS), i.e., it offers for the research community an open access to our optimization approach. Moreover, the proposed web service can be even included in research future works with a very small programming effort.To favor utilization of the web service and to prove the facility in which the service could be used, we provide an example in Java proving that it is possible to obtain in less than 10min a client application using the different methods exposed by this web service. Such usage extends to classical library inclusion in program with the difference that a method is called in the client side and represents an execution on the server.The Web Service paradigm is a new approach in spreading algorithms and therefore this paper stands at the crossroads of optimization research community and the web service community expectations. The GRASP×ELS provided in the web service, is a state of the art method which competes with previously published ones and which has the advantage of being available for free, in any languages, everywhere contributing in spreading operational research contribution.

Enhanced Mobile Cloud Computing Platform

Mobile Cloud Computing is a technology that influences integrated resources of varied clouds and network technologies toward limitless mobility, functionality and storage. It serves a mass of mobile devices anywhere, anytime through different channels, being either Ethernet or Internet regardless of diverse environments and platforms; it also means to provide mobile users with data storage and processing power on a cloud computing platform. Still there are some problems integrating both Cloud Computing and Mobile Computing as Cloud Computing is not initially designed to be consumed from mobile devices with its limited resources; however the mobile devices could interact with cloud services containing drawbacks such as resources limitation, bandwidth, and unstable connection. In this paper we present Enhanced Cloud Computing Platform, which enhances the interaction between the mobile devices and web services through cloud platform for optimized mobile web service communication by providing an alternative architecture for the XML based SOAP services.

Discovering Heterogeneous Evolving Web Service Communities Using Semi-Supervised Non Negative Matrix Factorization

Discovering Heterogeneous Evolving Web Service Communities Using Semi-Supervised Non Negative Matrix Factorization