International Journal of Web and Grid Services (6 papers in press)
Towards the Optimality of QoS-aware Web Service Composition with Uncertainty
by Sen Niu, Guobing Zou, Yanglan Gan, Yang Xiang, Bofeng Zhang
Abstract: QoS-aware web service composition has recently become one of the most challenging research issues. Although much work has been investigated to solve the problem, they mainly focus on certain QoS of web services, while QoS with uncertainty exposes the most important characteristic in real and highly dynamic environment on the Internet. In this paper, with the consideration of uncertain service QoS and user's preferences, we model the issue of uncertain QoS-aware web service composition via interval number and translate it into a multi-objective optimization problem with global QoS constraints of user's preferences. The encoded optimization problem is solved by an non-deterministic multi-objective evolutionary algorithm, which takes advantage of new genetic encoding schema, the strategy of crossover and uncertain interval Pareto comparison. To validate the feasibility of our proposed approach, large-scale experiments have been conducted on our simulated datasets. The experimental results demonstrate that our proposed approach can effectively and efficiently help an active user find optimum composite service solutions set with satisfactory convergence.
Keywords: web services;uncertain QoS;web service composition;multi-objective optimization.
A Semantic Approach for Generating Government Processes
by Cherouana Amina, Bellatreche Ladjel, Mahdaoui Latifa, Medjahed Brahim
Abstract: In the last years, governments embraced business process management practices to improve their interactions and services with various stakeholders such as citizens, businesses, and other government agencies. Nevertheless, current government process management solutions are still very limited at the semantic level, leading to challenges in dealing with legal, social, organizational, political and economic constraints, collectively referred to as Context. In this paper, we introduce SGPM, a Semantic Government Process Management approach for the design and deployment of legally compliant government processes. The developed solution is mainly articulated around an ontological framework, with a high level of abstraction, allowing the explicit representation of legal context associated with government processes. It is connected to a defined legal meta-model that acts as legal context extraction guidelines and knowledge source. Moreover, this framework is substantiated by a legal features model allowing the semantic representation of structural relationships and dependencies between processes, sub-processes, as well as activities. The ontological framework is implemented as software assets, using OWL-DL, that constitute the kernel from which BPEL executable government processes are automatically generated.
Keywords: E-government; Government Process Management; Meta-modeling; Ontology; Legal Context; Compliance.
SAW-Q: A dynamic composition approach of REST services based on queue model
by Jesus Bellido, Rosa Alarcon, Cesare Pautasso, Carla Vairetti
Abstract: Service composition is one of the principles of service-oriented architecture; it enables reuse and allows developers to combine existing services in order to create new services that in turn can be part of another composition. Dynamic composition requires that service components are chosen from a set of services with equal or similar functionality at runtime, and possibly automatically. The adoption of the REST services in the industry has led to a growing number of services of this type, many with similar functionality. The existing dynamic composition techniques are method-oriented whereas REST is resource-oriented, and consider only traditional (WSDL/SOAP) services. We propose SAW-Q, an extension of Simple Additive Weighting (SAW), as a novel dynamic composition technique that follows the principles of the REST style. Additionally, SAW-Q models quality attributes as a function of the actual service demand instead of the traditional constant values. Our model is much more accurate when compared to real implementation, positively improving the quality of dynamic service compositions.
Keywords: SOA; REST services; dynamic composition; quality attributes.
Planning Operators of Concurrent RDF Stream Processing Queries
by Sejin Chun, Seungjun Yoon, Jooik Jung, Kyong-Ho Lee
Abstract: RDF Stream Processing(RSP), which aims to query data streams and Linked Data sets using common data model and query languages extended from RDF and SPARQL, is gaining popularity. However, most of the existing RSP engines do not provide any optimization techniques for shared join operators among query plans from concurrent queries. Many number of shared join operators can incur the waste of a lot of CPU resources like a processing memory. Moreover, queries on shared operators cause a slow response time because they must be re-evaluated without reusing intermediate results. To solve these problems, we propose an efficient method of optimizing query plans on multiple queries. First, the proposed method evicts some data that get notified from the streams in order to maintain an efficient memory usage. Second, the proposed method optimizes query plans to maximize the reuse of shared join results. Experimental results show that the proposed method has significant improvements in terms of memory consumption and latency, compared to the state-the-of-art methods.
Keywords: RDF; SPARQL; Stream processing; Distributed processing; Operator planning; Semantic Web.
An Auction Framework for DaaS in Cloud Computing and Its Evaluation
by Anjan Bandyopadhyay, Fatos Xhafa, Sajal Mukhopadhyay, Vikash Kumar Singh, Aniruddh Sharma
Abstract: Data as a Service (DaaS) is the next emerging technology in cloud computing research. Small clouds operating as a group may exploit the DaaS efficiently to perform the substantial amount of work. In this paper, an auction framework is studied and evaluated when the small clouds are strategic in nature. We present the system model and formal definition of the problem and its
experimental evaluation. Several auction DaaS-based mechanisms are proposed and their correctness and computational complexity is analyzed. To the best of our knowledge, this is the first and realistic attempt to study the DaaS in a strategic setting. We have evaluated the proposed approach under various simulation scenarios to judge on its usefulness and efficiency.
Keywords: Data as a Service, Auction, Mechanism Design, Micro Cloud
Special Issue on: Security for Cloud Computing
Searchable Symmetric Encryption Based on the
Inner Product for Cloud Storage
by Jun Yang, Shujuan Li, Xiaodan Yan, Baihui Zhang, Baojiang Cui
Abstract: Searchable encryption enables the data owner to store their own data after
encrypting them in the cloud. Searchable encryption also allows the client to search over
the data without leaking any information about it. In this paper, we rst introduce a
searchable symmetric encryption scheme based on the inner product: it is more ecient
to compute the inner product of two vectors. In our construction, the parties can be Data
Owners, Clients or the Cloud Server. The three parties communicate with each other
through the inner product to achieve the goal that the client can search the data in the
cloud without leaking any information on the data the owner stored in the cloud. We then
perform a security analysis and performance evaluation, which show that our algorithm
and construction are secure and ecient.
Keywords: Searchable Encryption; Searchable Symmetric Encryption; Inner Product;
the Cloud Server; Security.