The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Maria Bielikova - One of the best experts on this subject based on the ideXlab platform.
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automatic dynamic Web Service Composition a survey and problem formalization
Computing and Informatics \ Computers and Artificial Intelligence, 2011Co-Authors: Peter Bartalos, Maria BielikovaAbstract:The aim of Web Service Composition is to arrange multiple Services into workflows supplying complex user needs. Due to the huge amount of Web Services and the need to supply dynamically varying user goals, it is necessary to perform the Composition automatically. The objective of this article is to overview the issues of automatic dynamic Web Service Composition. We discuss the issues related to the semantics of Services, which is important for automatic Web ser- vice Composition. We propose a problem formalization contributing to the formal definition of the pre-/post-conditions, with possible value restrictions, and their re- lation to the semantics of Services. We also provide an overview of several existing approaches dealing with the problem of Web Service Composition and discuss the current achievements in the field and depict some open research areas.
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qos aware semantic Web Service Composition approach considering pre postconditions
International Conference on Web Services, 2010Co-Authors: Peter Bartalos, Maria BielikovaAbstract:Web Service Composition is a topic bringing several issues to be resolved. Our work deals with the effectiveness and scalability of Service Composition. During Composition we consider QoS and pre-/post-conditions of single Services to create a composite Service satisfying the user needs the best. Regarding pre-/post-conditions we propose an approach to fast determination of which Services produce results expected by the user, i.e. the post-condition of which Services implicates the desired condition defined in the user goal. This paper proposes also an approach to restriction on the Service space which provided a dramatic improvement in terms of Composition time.
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semantic Web Service Composition framework based on parallel processing
Congress on Evolutionary Computation, 2009Co-Authors: Peter Bartalos, Maria BielikovaAbstract:The process of semantic Web Service Composition arranges several Web Services into one composite Service to realize complex workflows with an exploitation of semantics. This paper proposes a framework to automatic semantic Web Service Composition. Its advantage is that a huge amount of computation is performed during preprocessing and the Composition approach is designed to exploit the parallel execution of processes which is nowadays supported in multiprocessor platforms. The framework is built to suit the WS Challenge competition requirements.
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fast and scalable semantic Web Service Composition approach considering complex pre postconditions
IEEE Congress on Services, 2009Co-Authors: Peter Bartalos, Maria BielikovaAbstract:The process of semantic Web Service Composition arranges several Web Services into one composite Service to realize complex workflows with an exploitation of semantics. This paper proposes an approach to automatic semantic Web Service Composition. Its advantage is good scalability regarding the complexity of user constraints and pre/post conditions. Based on these conditions it propagates the value restrictions constraint from the user goal through the overall composite Service. The resulting plan depicts all the possible branches of the workflow leading to a goal. This includes the automatic generation of the conditions deciding which branch will be chosen during the execution. Finally, our approach exploits available data which can be used as input parameters for Web Services. If these are not offered, it searches for a Web Service producing them.
Mengjie Zhang - One of the best experts on this subject based on the ideXlab platform.
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evolutionary computation for automatic Web Service Composition an indirect representation approach
Journal of Heuristics, 2018Co-Authors: Alexandre Sawczuk Da Silva, Mengjie ZhangAbstract:Web Services have become increasingly popular in recent years, and they are especially suitable to the process of Web Service Composition, which is when several Services are combined to create an application that accomplishes a more complex task. In recent years, significant research efforts have been made on developing approaches for performing Quality of Service -aware Web Service Composition. Evolutionary computing (EC) techniques have been widely used for solving this problem, since they allow for the quality of Compositions to be optimised, meanwhile also ensuring that the solutions produced have the required functionality. Existing EC-based Composition approaches perform constrained optimisation to produce solutions that meet those requirements, however these constraints may hinder the effectiveness of the search. To address this issue, a novel framework based on an indirect representation is proposed in this work. The core idea is to first generate candidate Service Compositions encoded as sequences of Services. Then, a decoding scheme is developed to transform any sequence of Services into a corresponding feasible Service Composition. Given a Service sequence, the decoding scheme builds the workflow from scratch by iteratively adding the Services to proper positions of the workflow in the order of the sequence. This is beneficial because it allows the optimisation to be carried out in an unconstrained way, later enforcing functionality constraints during the decoding process. A number of encoding methods and corresponding search operators, including the PSO, GA, and GP-based methods, are proposed and tested, with results showing that the quality of the solutions produced by the proposed indirect approach is higher than that of a baseline direct representation-based approach for twelve out of the thirteen datasets considered. In particular, the method using the variable-length sequence representation has the most efficient execution time, while the fixed-length sequence produces the highest quality solutions.
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Genetic programming for QoS-aware Web Service Composition and selection
Soft Computing, 2016Co-Authors: Alexandre Sawczuk Da Silva, Hui Ma, Mengjie ZhangAbstract:Web Services, which can be described as functionality modules invoked over a network as part of a larger application are often used in software development. Instead of occasionally incorporating some of these Services in an application, they can be thought of as fundamental building blocks that are combined in a process known as Web Service Composition. Manually creating Compositions from a large number of candidate Services is very time consuming, and developing techniques for achieving this objective in an automated manner becomes an active research field. One promising group of techniques encompasses evolutionary computing , which can effectively tackle the large search spaces characteristic of the Composition problem. Therefore, this paper proposes the use of genetic programming for Web Service Composition, investigating three variations to ensure the creation of functionally correct solutions that are also optimised according to their quality of Service . A variety of comparisons are carried out between these variations and two particle swarm optimisation approaches, with results showing that there is likely a trade-off between execution time and the quality of solutions when employing genetic programming and particle swarm optimisation. Even though genetic programming has a higher execution time for most datasets, the results indicate that it scales better than particle swarm optimisation.
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a memetic algorithm based indirect approach to Web Service Composition
Congress on Evolutionary Computation, 2016Co-Authors: Alexandre Sawczuk Da Silva, Mengjie ZhangAbstract:Web Service Composition is a popular area of investigation, since it encourages code reuse as opposed to re-implementing already existing functionality modules. Performing such Compositions manually can be quite time-consuming, since the functionality of each Service included in a solution must be fulfilled, while at the same time selecting candidates with the best possible quality of Service attributes. This work proposes a memetic algorithm that can perform Web Service Composition in a fully automated manner, optimising a sequence of Services that is then decoded into the final solution. The key advantage of this representation is that it separates the quality optimisation technique from the enforcement of correctness constraints, thus simplifying the overall Composition process and preventing solutions from being overly constrained. While this indirect Composition approach has been investigated earlier, the previous representation relied on weights for establishing a Service sequence and used PSO as the optimisation technique. In this work, on the other hand, sequences are directly represented using a vector of Services, which reduces the overall search space. Additionally, the memetic algorithm employed in this work is better at exploring solutions within promising areas of the search space. Experiments were conducted comparing the memetic approach with the previously proposed PSO, with two key findings. Firstly, the new representation reduces the overall execution time while maintaining the original solution quality. Secondly, the use of the memetic local search improves the overall quality of solutions, though it may incur longer execution times.
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graphevol a graph evolution technique for Web Service Composition
Database and Expert Systems Applications, 2015Co-Authors: Alexandre Sawczuk Da Silva, Mengjie ZhangAbstract:Web Service Composition can be thought of as the combination of reusable functionality modules available over the network to create applications that accomplish more complex tasks, and Evolutionary Computation (EC) techniques have been applied with success to this problem. Genetic Programming (GP) is a traditionally employed EC technique in this domain, and it encodes solutions as trees instead of their natural Directed Acyclic Graph (DAG) form. This complicates the enforcement of dependencies between Service nodes, which is much easier to accomplish in a DAG. To overcome this we propose GraphEvol, an evolutionary technique that uses DAGs directly to represent and evolve Web Service Composition solutions. GraphEvol is analogous to GP, but it implements the mutation and crossover operators differently. Experiments were carried out comparing GraphEvol with GP for a series of Composition tasks, with results showing that GraphEvol solutions either match or surpass the quality of those obtained using GP, at the same time relying on a more intuitive representation.
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a genetic programming approach to distributed qos aware Web Service Composition
Congress on Evolutionary Computation, 2014Co-Authors: Mengjie ZhangAbstract:Web Service Composition has emerged as a promising technique for building complex Web applications, thus supporting business-to-business and enterprise application integration. Nowadays there are increasing numbers of Web Services are distributed across the internet. For a given Service request there are many ways of Service Composition that can meet the Service functional requirements (inputs and outputs) but have different qualities of Services (QoS), like response time or execution cost. QoS-aware Web Service Composition seeks to find a Service Composition with optimized QoS properties. Genetic Programming is an efficient tool for tacking such optimization problems efficiently. This paper proposes a novel GP-based approach for distributed Web Service Composition where multiple QoS constraints are considered simultaneously. A series of experiments have been conducted to evaluate the proposed approach with test data. The results show that our approach is efficient and effective to find a near-optimal Service Composition solution in the context of distributed Service environment.
Peter Bartalos - One of the best experts on this subject based on the ideXlab platform.
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automatic dynamic Web Service Composition a survey and problem formalization
Computing and Informatics \ Computers and Artificial Intelligence, 2011Co-Authors: Peter Bartalos, Maria BielikovaAbstract:The aim of Web Service Composition is to arrange multiple Services into workflows supplying complex user needs. Due to the huge amount of Web Services and the need to supply dynamically varying user goals, it is necessary to perform the Composition automatically. The objective of this article is to overview the issues of automatic dynamic Web Service Composition. We discuss the issues related to the semantics of Services, which is important for automatic Web ser- vice Composition. We propose a problem formalization contributing to the formal definition of the pre-/post-conditions, with possible value restrictions, and their re- lation to the semantics of Services. We also provide an overview of several existing approaches dealing with the problem of Web Service Composition and discuss the current achievements in the field and depict some open research areas.
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qos aware semantic Web Service Composition approach considering pre postconditions
International Conference on Web Services, 2010Co-Authors: Peter Bartalos, Maria BielikovaAbstract:Web Service Composition is a topic bringing several issues to be resolved. Our work deals with the effectiveness and scalability of Service Composition. During Composition we consider QoS and pre-/post-conditions of single Services to create a composite Service satisfying the user needs the best. Regarding pre-/post-conditions we propose an approach to fast determination of which Services produce results expected by the user, i.e. the post-condition of which Services implicates the desired condition defined in the user goal. This paper proposes also an approach to restriction on the Service space which provided a dramatic improvement in terms of Composition time.
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semantic Web Service Composition framework based on parallel processing
Congress on Evolutionary Computation, 2009Co-Authors: Peter Bartalos, Maria BielikovaAbstract:The process of semantic Web Service Composition arranges several Web Services into one composite Service to realize complex workflows with an exploitation of semantics. This paper proposes a framework to automatic semantic Web Service Composition. Its advantage is that a huge amount of computation is performed during preprocessing and the Composition approach is designed to exploit the parallel execution of processes which is nowadays supported in multiprocessor platforms. The framework is built to suit the WS Challenge competition requirements.
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fast and scalable semantic Web Service Composition approach considering complex pre postconditions
IEEE Congress on Services, 2009Co-Authors: Peter Bartalos, Maria BielikovaAbstract:The process of semantic Web Service Composition arranges several Web Services into one composite Service to realize complex workflows with an exploitation of semantics. This paper proposes an approach to automatic semantic Web Service Composition. Its advantage is good scalability regarding the complexity of user constraints and pre/post conditions. Based on these conditions it propagates the value restrictions constraint from the user goal through the overall composite Service. The resulting plan depicts all the possible branches of the workflow leading to a goal. This includes the automatic generation of the conditions deciding which branch will be chosen during the execution. Finally, our approach exploits available data which can be used as input parameters for Web Services. If these are not offered, it searches for a Web Service producing them.
Rajkumar Buyya - One of the best experts on this subject based on the ideXlab platform.
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Computational Intelligence Based QoS-Aware Web Service Composition: A Systematic Literature Review
IEEE Transactions on Services Computing, 2017Co-Authors: Chandrashekar Jatoth, G.r. Gangadharan, Rajkumar BuyyaAbstract:Web Service Composition concerns the building of new value added Services by integrating the sets of existing Web Services. Due to the seamless proliferation of Web Services, it becomes difficult to find a suitable Web Service that satisfies the requirements of users during Web Service Composition. This paper systematically reviews existing research on QoS-aware Web Service Composition using computational intelligence techniques (published between 2005 and 2015). This paper develops a classification of research approaches on computational intelligence based QoS-aware Web Service Composition and describes future research directions in this area. In particular, the results of this study confirms that new meta-heuristic algorithms have not yet been applied for solving QoS-aware Web Services Composition.
Parag Doshi - One of the best experts on this subject based on the ideXlab platform.
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Towards Automated RESTful Web Service Composition
2009 IEEE International Conference on Web Services, 2009Co-Authors: Haibo Zhao, Parag DoshiAbstract:Emerging as the popular choice for leading Internet companies to expose internal data and resources, RESTful Web Services are attracting increasing attention in the industry. While automating WSDL/SOAP based Web Service Composition has been extensively studied in the research community, automated RESTful Web Service Composition in the context of Service-oriented architecture (SOA), to the best of our knowledge, is less explored. As an early paper addressing this problem, this paper discusses the challenges of composing RESTful Web Services and proposes a formal model for describing individual Web Services and automating the Composition. It demonstrates our approach by applying it to a real-world RESTful Web Service Composition problem. This paper represents our initial efforts towards the problem of automated RESTful Web Service Composition. We are hoping that it will draw interests from the research community on Web Services, and engage more researchers in this challenge.
