Chantal Cherifi

Benefits of Semantics on Web Service Composition from a Complex Network Perspective

The number of publicly available Web services (WS) is continuously growing, and in parallel, we are witnessing a rapid development in semantic-related web technologies. The intersection of the semantic web and WS allows the development of semantic WS. In this work, we adopt a complex network perspective to perform a comparative analysis of the syntactic and semantic approaches used to describe WS. From a collection of publicly available WS descriptions, we extract syntactic and semantic WS interaction networks. We take advantage of tools from the complex network field to analyze them and determine their properties. We show that WS interaction networks exhibit some of the typical characteristics observed in real-world networks, such as short average distance between nodes and community structure. By comparing syntactic and semantic networks through their properties, we show the introduction of semantics in WS descriptions should improve the composition process.

Community structure in interaction web service networks

Many real-world complex systems such as social, biological, information as well as technological systems results of a decentralised and unplanned evolution which leads to a common structuration. Irrespective of their origin, these so-called complex networks typically exhibit small-world and scale-free properties. Another common feature is their organisation into communities. In this paper, we introduce models of interaction networks based on the composition process of syntactic and semantic web services. An extensive experimental study conducted on a benchmark of real web services shows that these networks possess the typical properties of complex networks small-world, scale-free. Unlike most social networks, they are not transitive. Using a representative sample of community detection algorithms, a community structuration is revealed. The comparative evaluation of the discovered community structures shows that they are very similar in terms of content. Furthermore, the analysis performed on the community structures and on the communities themselves, leads us to conclude that their topological properties are consistent.

Overlapping Community Structure in Co-authorship Networks: A Case Study

Community structure is one of the key properties of real-world complex networks. It plays a crucial role in their behaviors and topology. While an important work has been done on the issue of community detection, very little attention has been devoted to the analysis of the community structure. In this paper, we present an extensive investigation of the overlapping community network deduced from a large-scale co-authorship network. The nodes of the overlapping community network rep-resent the functional communities of the co-authorship network, and the links account for the fact that communities share some nodes in the co-authorship network. The comparative evaluation of the topological properties of these two networks shows that they share similar topological properties. These results are very interesting. Indeed, the network of communities seems to be a good representative of the original co-authorship network. With its smaller size, it may be more practical in order to realize various analyses that cannot be performed easily in large-scale real-world networks.

On Flexible Web Services Composition Networks

The semantic Web service community develops efforts to bring semantics to Web service descriptions and allow automatic discovery and composition. However, there is no widespread adoption of such descriptions yet, because semantically defining Web services is highly complicated and costly. As a result, production Web services still rely on syntactic descriptions, key-word based discovery and predefined compositions. Hence, more advanced research on syntactic Web services is still ongoing. In this work we build syntactic composition Web services networks with three well known similarity metrics, namely Levenshtein, Jaro and Jaro-Winkler. We perform a comparative study on the metrics performance by studying the topological properties of networks built from a test collection of real-world descriptions. It appears Jaro-Winkler finds more appropriate similarities and can be used at higher thresholds. For lower thresholds, the Jaro metric would be preferable because it detect less irrelevant relationships.

A Comparative Study of Web Services Composition Networks

Web services growth makes the composition process a hard task to solve. This numerous interacting elements can be adequately represented by a network. Discovery and composition can benefit from the knowledge of the network structure. In this paper, we investigate the topological properties of two models of syntactic and semantic Web services composition networks: dependency and interaction. Results show that they share a similar organization characterized by the small-world property, a heavy-tailed degree distribution and a low transitivity value. Furthermore, the networks are disassortative.

MATAWS: A Multimodal Approach for Automatic WS Semantic Annotation

Many recent works aim at developing methods and tools for the processing of semantic Web services. In order to be properly tested, these tools must be applied to an appropriate benchmark, taking the form of a collection of semantic WS descriptions. However, all of the existing publicly available collections are limited by their size or their realism (use of randomly generated or resampled descriptions). Larger and realistic syntactic (WSDL) collections exist, but their semantic annotation requires a certain level of automation, due to the number of operations to be processed. In this article, we propose a fully automatic method to semantically annotate such large WS collections. Our approach is multimodal, in the sense it takes advantage of the latent semantics present not only in the parameter names, but also in the type names and structures. Concept-to-word association is performed by using Sigma, a mapping of WordNet to the SUMO ontology. After having described in details our annotation method, we apply it to the larger collection of real-world syntactic WS descriptions we could find, and assess its efficiency.

Complex Networks & Their Applications VI

This book highlights cutting-edge research in the field of network science, offering scientists, researchers, students and practitioners a unique update on the latest advances in theory and a multitude of applications. It presents the peer-reviewed proceedings of the VI International Conference on Complex Networks and their Applications (COMPLEX NETWORKS 2017), which took place in Lyon on November 29 – December 1, 2017. The carefully selected papers cover a wide range of theoretical topics such as network models and measures; community structure, network dynamics; diffusion, epidemics and spreading processes; resilience and control as well as all the main network applications, including social and political networks; networks in finance and economics; biological and ecological networks and technological networks.

Performance monitoring framework for service oriented system lifecycle

Service oriented systems are highly dynamic systems composed of several web services. One of the most important challenges in service oriented systems is to deliver acceptable quality of service. For this purpose, it is required to monitor quality of service along different activities of service oriented system. Existing research focuses on specific activities but do not take into account all the activities of service oriented system together at the infrastructure level. In this paper, we present performance monitoring framework to provide support for the whole service oriented system lifecycle. Our framework integrates several ontologies to monitor the performance of service oriented systems in order to ensure their sustainability. We design a base Service Monitoring Ontology that captures all the information about the service domain. Along with that we design ontologies for technical indicators at service level, binding level, composition level and server level. We conduct a performance evaluation over real web services using suitable estimators for response time, delay, loss and more.

Identifying Performance Objectives to Guide Service Oriented Architecture Layers

Service oriented architecture is emerging as a powerful paradigm for organizations that need to integrate their applications within and across organizational boundaries. Organizations need to take decisions more quickly and need to change those decisions dynamicaly. Delivering an adequate level of performance is a critical and significant challenge that requires monitoring along the different layers of service oriented architecture. Current monitoring systems are designed to support specific layers but do not fulfil the requirements of all the layers of service oriented architecture. Ontologies on the semantic web standardize and formalize the concepts and store domain knowledge for effective decision making. In this paper, we propose performance monitoring framework for various layers of service oriented architecture. It integrates various ontologies to monitor the performance at the service oriented layers in order to ensure their sustainability. We design a Service Performance Ontology that captures all the information about the service domain. Along with that we design ontologies for ensuring performance at service level, binding level, composition level and server level. We conduct a performance evaluation over real web services using suitable estimators for response time, delay, loss and more.

Performance Oriented Decision Making to Guide Web Service Lifecycle

Service composition networks are becoming increasingly important and more critical for the enterprise collaborations. The sustainability of service based systems is driven with the support of performance metrics analysis for decision making. Some of the existing works only focused performance at messaging level. Ontology based performance monitoring techniques did not provide the recommendation model for better quality of service. In this paper we propose a semantic service recommendation framework (SSRF) based on Service Networks Monitoring (SNM) concepts. This framework includes creation of Service Network Monitoring Ontology (SNMOnt), extracting traces of technical indicators for services and storing decision data in the existing database. The decision support covers the unavailability of service and recommendation of services based on technical indicators. Our framework is meant to support the creation of shared domain knowledge ensuring an optimal decision making system for web service lifecycle.