Youakim Badr

LinkedWS: A Novel Web Services Discovery Model Based on the Metaphor of Social Networks

Abstract Web services are increasingly becoming the de facto implementation for the service-oriented architecture paradigm for enterprises due to their ease of use. Nevertheless, discovering these Web services is still hindered by many challenges that are partially attributed to shortcomings found in the discovery registry models (e.g., UDDI) used nowadays. These registries do not, for example, capture the rich information resulting from the various types of interactions between Web services. To address these shortcomings, and inspired by the conventional human social networks on the net, like Facebook and Twitter, we develop LinkedWS , a social networks discovery model to capture the different interactions that occur between Web services. Based on these interactions, specialized relationships are spawned and discerned. Examples of these relationships are collaboration and substitution. This paper describes LinkedWS and its potential, and reports on its implementation status.

Enhancing web service selection by QoS-based ontology and WS-policy

The Service Oriented Architecture enables the development of flexible large scale-applications in open environments by dynamically combining Web services. Nevertheless, current techniques fail to address the problem of selecting adequate services to meet service consumer needs. Service selection must take into account non-functional parameters especially the Quality of Service (QoS). In this work we propose a Web service selection approach based on QoS attributes. We extend the WS-Policy to represent QoS policies. We apply ontological concepts to WS-policy in order to enable semantic matching. Publishing QoS policies is also examined in this work. We propose to extend the UDDI register to handle QoS-based policies.

The Integration of Corporate Security Strategies in Collaborative Business Processes

In response to increasing economical constraints, enterprise organization has evolved toward new structures such as networked enterprise, supply chains, virtual enterprise, or collaborative business organizations. This structural organization requires the interoperability of business processes (BPs)and information systems. Dealing with interoperability often leads to the deployment of Service-Oriented Architecture (SOA) based on Enterprise Service Bus (ESB) to design agile collaborative BPs and publish and compose new services. In order to protect each partners own interests, security strategies must be developed and integrated in the service environment. Unfortunately, traditional security approaches deal with security concerns from a technical perspective (i.e., data transmission or authentication, etc.) and do not support end-to-end security in a distributed environment of business services and collaborative processes. In this paper, we attempt to improve end-to-end security by annotating service descriptions with security objectives used to generate convenient quality of protection (QoP) agreements between partners. Conversely, agreements are processed by a dedicated matching module with respect to security requirements and preferences to select business services, and then, compose their appropriate technical security services.

Emergent Web Intelligence: Advanced Information Retrieval

Web Intelligence explores the impact of artificial intelligence and advanced information technologies representing the next generation of Web-based systems, services, and environments, and designing hybrid web systems that serve wired and wireless users more efficiently. Multimedia and XML-based data are produced regularly and in increasing way in our daily digital activities, and their retrieval must be explored and studied in this emergent web-based era. Emergent Web Intelligence: Advanced information retrieval provides reviews of the related cuttingedge technologies and insights. It is valuable companion and comprehensive reference for undergraduate and postgraduate students who are taking a course in Web intelligence and need to study current concepts of retrieval of multimedia and XML-based data, developers who need to implement advanced search engine and make benefit of web intelligence technologies, researchers who desire to understand exiting approaches, pin down their limits, and identify several future directions. The book is organized in self-contained chapters to provide greatest reading flexibility.

Hybrid Evolutionary Algorithm for Solving Global Optimization Problems

Differential Evolution (DE) is a novel evolutionary approach capable of handling non-differentiable, non-linear and multi-modal objective functions. DE has been consistently ranked as one of the best search algorithm for solving global optimization problems in several case studies. This paper presents a simple and modified hybridized Differential Evolution algorithm for solving global optimization problems. The proposed algorithm is a hybrid of Differential Evolution (DE) and Evolutionary Programming (EP). Based on the generation of initial population, three versions are proposed. Besides using the uniform distribution (U-MDE), the Gaussian distribution (G-MDE) and Sobol sequence (S-MDE) are also used for generating the initial population. Empirical results show that the proposed versions are quite competent for solving the considered test functions.

Towards a framework for weaving social networks principles into web services discovery

Despite the regular updates of the existing discovery techniques, the discovery of Web services continues to exacerbate users due to the large number of available Web services on the Internet. Different needs trigger the discovery of Web services such as developing new, value-added composite services and sustaining the high availability of other peers. These needs reveal three types of relationships between Web services, which are substitution, competition, and collaboration. The proposed framework includes tools that capture and update these relationships into social networks so that Web services discovery can be made smooth. Some implementation and simulation details are, also, discussed in this paper.

A security policy framework for context-aware and user preferences in e-services

In todays dynamic and distributed markets a large spectrum of services is delivered through information and communication technologies. Emerging markets of e-services lie at the intersection of non-traditional user behaviour, and cyber-partnerships of enterprises to deliver innovative services. Current approaches to manage and control security demonstrate lacks in terms of security policy matching and integration in heterogeneous e-service environments. In this paper, we introduce a framework to support role-based access control for distributed services focusing on the integration of customer preferences. The framework aims to collect and generate policy-based security measures in cross-organisational scenarios. In addition to catering to specifications of security and business policies, the ability to integrate contextual information and user preferences make the role-based framework flexible and express a variety of access policies that provide a just-in-time permission activation.

Economic Load Dispatch Using a Chemotactic Differential Evolution Algorithm

This paper presents a novel stochastic optimization approach to solve constrained economic load dispatch (ELD) problem using Hybrid Bacterial Foraging-Differential Evolution optimization algorithm. In this hybrid approach computational chemotaxis of BFOA, which may also be viewed as a stochastic gradient search, has been coupled with DE type mutation and crossover of the optimization agents. The proposed methodology easily takes care of solving non-convex economic load dispatch problems along with different constraints like transmission losses, dynamic operation constraints (ramp rate limits) and prohibited operating zones. Simulations were performed over various standard test systems with different number of generating units and comparisons are performed with other existing relevant approaches. The findings affirmed the robustness and proficiency of the proposed methodology over other existing techniques.

Automatic Clustering Using a Synergy of Genetic Algorithm and Multi-objective Differential Evolution

This paper applies the Differential Evolution (DE) and Genetic Algorithm (GA) to the task of automatic fuzzy clustering in a Multi-objective Optimization (MO) framework. It compares the performance a hybrid of the GA and DE (GADE) algorithms over the fuzzy clustering problem, where two conflicting fuzzy validity indices are simultaneously optimized. The resultant Pareto optimal set of solutions from each algorithm consists of a number of non-dominated solutions, from which the user can choose the most promising ones according to the problem specifications. A real-coded representation of the search variables, accommodating variable number of cluster centers, is used for GADE. The performance of GADE has also been contrasted to that of two most well-known schemes of MO.

Towards a Unified Approach for Business Process Modeling Using Context-Based Artifacts and Web Services

Service-Oriented Architecture is a paradigm for modeling and enacting business processes that promotes improved flexibility and monitor ability through the composition of loosely-coupled Web services. However, such process-centric composition, with focus on invoking Web services to reach a stated goal, still does not provide the desired flexibility. Web services implementations are typically locked into the business logic of the business processes that they implement. Additionally,monitoring such Web services compositions becomes cumbersome especially for business analysts and managers who are not IT experts. To address these issues, this paper presents a unified process- and data-centric approach with focus on Web services as a driving element to the changes affecting both processes and data. In this approach a business process is modeled as a collection of interacting (business) artifacts, each of which behaves as per a predefined state transition system called Artifact Life-Cycle (ALC). An ALC is enriched with contextual details, which permits business process execution monitoring. Throughout this paper, a realistic running example in the purchase order domain is used for illustration purposes.