32,347 research outputs found
A Matching Algorithm for Selecting Web Services Based on Non-Functional Features
Searching for a Web service that meets the user requirements can be a complex task especially when the system starts to scale up by increasing the number of Web services, w, in the UDDI registry and by enlarging the number of QoS features (f) by which each Web service is described. This can be perceived as the commonly known nearest neighbor search problem, which typically imposes a time or storage complexity that is exponential in f. In this work, we present a new algorithm (wsSVD) that is founded on the algebraic matrix operation called Singular Value Decomposition (SVD). The basic idea is to encode the features of each Web service by a single value using the SVD. When a user seeks a Web service based on some specific requirements, these requirements get encoded by a single value using the same algorithm, and the matching process takes place in order to find the closest Web service that fulfills the user requirements. Our experiments show that the wsSVD algorithm performs and scales up well in comparison with other matching algorithms
Advanced service monitoring configurations with SLA decomposition and selection
Service Level Agreements (SLAs) for Software Services aim to clearly identify the service level commitments established between service requesters and providers. The commitments that are agreed however can be expressed in complex notations through a combination of expressions that need to evaluated and monitored efficiently. The dynamic allocation of the responsibility for monitoring SLAs (and often different parts within them) to different monitoring components is necessary as both SLAs and the components available for monitoring them may change dynamically during the operation of a service based system. In this paper we discuss an approach to supporting this dynamic configuration, and in particular, how SLAs expressed in higher-level notations can be efficiently decomposed and appropriate monitoring components dynamically allocated for each part of the agreements. The approach is illustrated with mechanical support in the form of a configuration service which can be incorporated into SLA-based service monitoring infrastructures
Semantic-driven matchmaking of web services using case-based reasoning
With the rapid proliferation of Web services as the medium of choice to securely publish application services beyond the firewall, the importance of accurate, yet flexible matchmaking of similar services gains importance both for the human user and for dynamic composition engines. In this paper, we present a novel approach that utilizes the case based reasoning methodology for modelling dynamic Web service discovery and matchmaking. Our framework considers Web services execution experiences in the decision making process and is highly adaptable to the service requester constraints. The framework also utilises OWL semantic descriptions extensively for implementing both the components of the CBR engine and the matchmaking profile of the Web services
Non-functional Property based service selection: A survey and classification of approaches
In recent years there has been much effort dedicated to developing approaches for service selection based on non-functional properties. It is clear that much progress has been made, and by considering the individual approaches there is some overlap in functionality, but obviously also some divergence. In this paper we contribute a classification of approaches, that is, we define a number of criteria which allow to differentiate approaches. We use this classification to provide a comparison of existing approaches and in that sense provide a survey of the state of the art of the field. Finally we make some suggestions as to where the research in this area might be heading and which new challenges need to be addressed
Web Data Extraction, Applications and Techniques: A Survey
Web Data Extraction is an important problem that has been studied by means of
different scientific tools and in a broad range of applications. Many
approaches to extracting data from the Web have been designed to solve specific
problems and operate in ad-hoc domains. Other approaches, instead, heavily
reuse techniques and algorithms developed in the field of Information
Extraction.
This survey aims at providing a structured and comprehensive overview of the
literature in the field of Web Data Extraction. We provided a simple
classification framework in which existing Web Data Extraction applications are
grouped into two main classes, namely applications at the Enterprise level and
at the Social Web level. At the Enterprise level, Web Data Extraction
techniques emerge as a key tool to perform data analysis in Business and
Competitive Intelligence systems as well as for business process
re-engineering. At the Social Web level, Web Data Extraction techniques allow
to gather a large amount of structured data continuously generated and
disseminated by Web 2.0, Social Media and Online Social Network users and this
offers unprecedented opportunities to analyze human behavior at a very large
scale. We discuss also the potential of cross-fertilization, i.e., on the
possibility of re-using Web Data Extraction techniques originally designed to
work in a given domain, in other domains.Comment: Knowledge-based System
Supporting Semantically Enhanced Web Service Discovery for Enterprise Application Integration
The availability of sophisticated Web service discovery mechanisms is an essential prerequisite for increasing the levels of efficiency and automation in EAI. In this chapter, we present an approach for developing service registries building on the UDDI standard and offering semantically-enhanced publication and discovery capabilities in order to overcome some of the known limitations of conventional service registries. The approach aspires to promote efficiency in EAI in a number of ways, but primarily by automating the task of evaluating service integrability on the basis of the input and output messages that are defined in the Web service’s interface. The presented solution combines the use of three technology standards to meet its objectives: OWL-DL, for modelling service characteristics and performing fine-grained service matchmaking via DL reasoning, SAWSDL, for creating semantically annotated descriptions of service interfaces, and UDDI, for storing and retrieving syntactic and semantic information about services and service providers
An Integrated Semantic Web Service Discovery and Composition Framework
In this paper we present a theoretical analysis of graph-based service
composition in terms of its dependency with service discovery. Driven by this
analysis we define a composition framework by means of integration with
fine-grained I/O service discovery that enables the generation of a graph-based
composition which contains the set of services that are semantically relevant
for an input-output request. The proposed framework also includes an optimal
composition search algorithm to extract the best composition from the graph
minimising the length and the number of services, and different graph
optimisations to improve the scalability of the system. A practical
implementation used for the empirical analysis is also provided. This analysis
proves the scalability and flexibility of our proposal and provides insights on
how integrated composition systems can be designed in order to achieve good
performance in real scenarios for the Web.Comment: Accepted to appear in IEEE Transactions on Services Computing 201
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