Papers by Chantal Cherifi
Today, the deployment of Web services in many
enterprise applications has gained much attention. ... more Today, the deployment of Web services in many
enterprise applications has gained much attention. Service
network inhibits certain common properties as they arise
spontaneously and are subject to high fluctuation. The
objective of consumer is to compose services for stable
business processes in coherence with their legacy system
capabilities and with better quality of services. For this
purpose we have proposed a dynamic decision model that
integrates several performance metrics and attributes to
monitor the performance of service oriented systems in order
to ensure their sustainability. Based on the available metrics,
we have identified performance metrics criteria and classified
into categories like time based QoS, size based QoS, combined
QoS and estimated attributes. Then we have designed service
network monitoring ontology (SNM). Our decision model will
take user query and SNM as input, measures the performance
capabilities and suggests some new performance
configurations like selected service is not available, physical
resource is not available and no maintenance will be available
for the selected service for composition.
Smart city services have an inevitable role in
addressing the complexity of modern city operation... more Smart city services have an inevitable role in
addressing the complexity of modern city operation. Smart
transport, smart parking, smart energy, smart water and many
others are examples of vertical smart city systems that are
mainly concerned with its particular domain. Realizing the
full promise of smart city will require interoperability among
those systems and data fusion between heterogeneous
components from different domains. In this regard, many
standardization organizations have been working on modeling
smart city and similar or related systems and concepts, such
as Internet of Things (IoT) and Cyber Physical Systems (CPS),
to ensure common technical grounding and architectural
principles. Though, there is still a need to address the higherlevel
requirements of smart city as a complete ecosystem. To
this end, this paper discusses different Smart City solutions
and highlights lifecycle based modeling to better integrate
people, processes, and systems; and assure information
consistency, traceability, and long-term archiving.
Community structure is one of the key properties
of real-world complex networks. It plays a cruci... more 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 represent
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.
The constraints on business process applications in terms of automation and reusability makes the... more The constraints on business process applications in terms of automation and reusability makes their development a challenging issue. To manage the variety of business process requirements, agile methods are required. Classically, business processes are implemented in a static way, what makes any evolution costly to realize. To cope with those needs, we propose the use of Web services to implement business processes. Web services and the designed business processes are stored in ontologies. An efficient multi-criteria service selection algorithm performs a semantic matching between the ontologies. It selects the most appropriate Web services among the existing ones for implementing a business process. This algorithm considers the business context, functional and QoS properties of the Web services. The user is asked for weights on QoS attributes. WordNet is integrated to solve the synonym problems. To be closer to reality and for more accurate results, our algorithm takes into account the changing values of QoS over time.
1. Cherifi, C., : Enhancing Web Services Classification Using Similarity Networks. In Int. Ubiquitous Computing and Communication Journal (UbiCC), Vol. 9 N°1, (2014), 2014
The diversity of users' needs and the ever growing number of Web services makes the discovering o... more The diversity of users' needs and the ever growing number of Web services makes the discovering of the appropriate ones a challenging issue. In order to enhance the composition life cycle, an efficient organization of the Web services landscape must be integrated within discovery and substitution mechanisms. Classically, Web services are organized into non overlapping categories based on a similarity metric. The main drawback of this approach is that it lacks the precise information that is needed toward Web service selection within a category. In this paper, we propose a finer organization based on networks. The nodes of the networks are the operations of the Web services while the links join similar operations. Four similarity measures based on the comparison of input and output parameters values of Web services operations are presented. A comparative evaluation of the topological structure of the corresponding networks is performed on a benchmark of semantically annotated Web services. Results show that, with this approach, we get a deeper and more subtle vision of the functional similarities between Web services.
Cherifi, C: Complex Networks and Web Services. In Complex Networks and their applications. Cambridge Scholars Publishing, pp.285-319 (2014), 2014
Many real-world complex systems such as social, biological, information as well as technological ... more Many real-world complex systems such as social, biological, information as well as technological systems results of a decentralized 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.
In order to deal efficiently with the exponential growth of the Web services landscape in composi... more In order to deal efficiently with the exponential growth of the Web services landscape in composition life cycle activities, it is necessary to have a clear view of its main features. As for many situations where there is a lot of interacting entities, the complex networks paradigm is an appropriate approach to analyze the interactions between the multitudes of Web services. In this paper, we present and investigate the main interactions between semantic Web services models from the complex network perspective. Results show that both parameter and operation networks exhibit the main characteristics of typical real-world complex networks such as the “small-world” property and an inhomogeneous degree distribution. These results yield valuable insight in order to develop composition search algorithms, to deal with security threat in the composition process and on the phenomena which characterize its evolution.
Web service composition is the process of synthesizing a new composite service using a set of ava... more Web service composition is the process of synthesizing a new composite service using a set of available Web services in order to satisfy a client request that cannot be treated by any available Web services. The Web services space is a dynamic environment characterized by a huge number of elements. Furthermore, many Web services are offering similar functionalities. In this paper we propose a model for Web service composition designed to address the scale effect and the redundancy issue. The Web services space is represented by a two-layered network architecture. A concrete similarity network layer organizes the Web services operations into communities of functionally similar operations. An abstract interaction network layer represents the composition relationships between the sets of communities. Composition synthesis is performed by a two-phased graph search algorithm. First, the interaction network is mined in order to discover abstract solutions to the request goal. Then, the abstract compositions are instantiated with concrete operations selected from the similarity network. This strategy allows an efficient exploration of the Web services space. Furthermore, operations grouped in a community can be easily substituted if necessary during the composition's synthesis's process.
Web services substitution is one of the most challenging tasks for automating the composition pro... more Web services substitution is one of the most challenging tasks for automating the composition process of multiple Web services. It aims to improve performances and to deal efficiently with Web services failures. Many existing solutions have approached the problem through classification of substitutable Web services. To go a step further, we propose in this paper a network based approach where nodes are Web services operations and links join similar operations. Four similarity measures based on the comparison of input and output parameters values of Web services operations are presented. A comparative evaluation of the topological structure of the corresponding networks is performed on a benchmark of semantically annotated Web services. Results show that this approach allows a more detailed analysis of substitutable Web services.
Web services growth makes the composition process a hard task to solve. This numerous interacting... more 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.
Advances in Information …, 2011
Web services represent a system with a huge number of units and many various and complex interact... more Web services represent a system with a huge number of units and many various and complex interactions. Complex networks as a tool for modelling and analyzing natural environments seem to be well adapted to such a complex system. To describe a set of Web services we propose three Web services network models based on the notions of dependency, interaction and similarity. Using the WS-NEXT extractor we instantiate the models with a collection of Web services descriptions. We take advantage of complex network properties to provide an analyzis of the Web services networks. Those networks and the knowledge of their toplogical properties can be exploited for the discovery and composition processes.
Networked Digital …, 2011
Many recent works aim at developing methods and tools for the processing of semantic Web services... more 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.
The semantic Web service community develops efforts to bring semantics to Web service description... more 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.
Proceedings of The 5th …, 2011
In this article, a Web services network extractor toolkit, WS-NEXT (WS Network EXtractor Toolkit)... more In this article, a Web services network extractor toolkit, WS-NEXT (WS Network EXtractor Toolkit), is presented. WS-NEXT allows extraction of interaction and dependency WS networks. Networks can be extracted from syntactic and semantic WS descriptions. Such network structures can be analyzed using complex network tools. We provide examples of networks extracted from a publicly available WS collection. Additionally, we give some networks analysis results.
Strategic Advantage of …, 2010
The number of publicly available Web services (WS) is continuously growing. To perform efficient ... more The number of publicly available Web services (WS) is continuously growing. To perform efficient WS discovery, it is desirable to organize the WS space. Works in this direction propose to group WS according to certain shared properties. Such groups commonly called communities are based either on similarity or on interaction between WS. In this paper we focus on the former, and propose a new network-based approach to extract communities from a WS collection. This process is three-stepped: first we define several similarity functions able to compare WS operations, second we use them to build so-called similarity networks, and third we identify communities under the form of specific structures in these networks. We apply our method on a collection of real-world WS and comment the resulting communities. Finally, we additionally provide an analysis and an interpretation of our similarity networks with a complex networks perspective.
Zavoral et al.(Eds), NDT, 2010
The number of publicly available Web services (WS) is continuously growing, and in parallel, we a... more The number of publicly available Web services (WS) is continuously growing, and in parallel, we are witnessing a rapid development in semanticrelated 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.
… Conference of New …, 2010
Along with a continuously growing number of publicly available Web services (WS), we are witnessi... more Along with a continuously growing number of publicly available Web services (WS), we are witnessing a rapid development in semantic-related web technologies, which lead to the apparition of semantically described WS. In this work, we perform a comparative analysis of the syntactic and semantic approaches used to describe WS, from a complex network perspective. First, we extract syntactic and semantic WS dependency networks from a collection of publicly available WS descriptions. Then, we take advantage of tools from the complex network field to analyze them and determine their topological properties. We show WS dependency networks exhibit some of the typical characteristics observed in real-world networks, such as small world and scale free properties, as well as community structure. By comparing syntactic and semantic networks through their topological properties, we show the introduction of semantics in WS description allows modeling more accurately the dependencies between parameters, which in turn could lead to improved composition mining methods.
C"est avec beaucoup d"émotion que je rédige cette page parce qu"elle symbolise un lieu de rassemb... more C"est avec beaucoup d"émotion que je rédige cette page parce qu"elle symbolise un lieu de rassemblement. Dans cet espace se trouvent réunies les personnes qui, à travers l"espace et le temps, ont partagé cette aventure.
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Papers by Chantal Cherifi
enterprise applications has gained much attention. Service
network inhibits certain common properties as they arise
spontaneously and are subject to high fluctuation. The
objective of consumer is to compose services for stable
business processes in coherence with their legacy system
capabilities and with better quality of services. For this
purpose we have proposed a dynamic decision model that
integrates several performance metrics and attributes to
monitor the performance of service oriented systems in order
to ensure their sustainability. Based on the available metrics,
we have identified performance metrics criteria and classified
into categories like time based QoS, size based QoS, combined
QoS and estimated attributes. Then we have designed service
network monitoring ontology (SNM). Our decision model will
take user query and SNM as input, measures the performance
capabilities and suggests some new performance
configurations like selected service is not available, physical
resource is not available and no maintenance will be available
for the selected service for composition.
addressing the complexity of modern city operation. Smart
transport, smart parking, smart energy, smart water and many
others are examples of vertical smart city systems that are
mainly concerned with its particular domain. Realizing the
full promise of smart city will require interoperability among
those systems and data fusion between heterogeneous
components from different domains. In this regard, many
standardization organizations have been working on modeling
smart city and similar or related systems and concepts, such
as Internet of Things (IoT) and Cyber Physical Systems (CPS),
to ensure common technical grounding and architectural
principles. Though, there is still a need to address the higherlevel
requirements of smart city as a complete ecosystem. To
this end, this paper discusses different Smart City solutions
and highlights lifecycle based modeling to better integrate
people, processes, and systems; and assure information
consistency, traceability, and long-term archiving.
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 represent
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.
enterprise applications has gained much attention. Service
network inhibits certain common properties as they arise
spontaneously and are subject to high fluctuation. The
objective of consumer is to compose services for stable
business processes in coherence with their legacy system
capabilities and with better quality of services. For this
purpose we have proposed a dynamic decision model that
integrates several performance metrics and attributes to
monitor the performance of service oriented systems in order
to ensure their sustainability. Based on the available metrics,
we have identified performance metrics criteria and classified
into categories like time based QoS, size based QoS, combined
QoS and estimated attributes. Then we have designed service
network monitoring ontology (SNM). Our decision model will
take user query and SNM as input, measures the performance
capabilities and suggests some new performance
configurations like selected service is not available, physical
resource is not available and no maintenance will be available
for the selected service for composition.
addressing the complexity of modern city operation. Smart
transport, smart parking, smart energy, smart water and many
others are examples of vertical smart city systems that are
mainly concerned with its particular domain. Realizing the
full promise of smart city will require interoperability among
those systems and data fusion between heterogeneous
components from different domains. In this regard, many
standardization organizations have been working on modeling
smart city and similar or related systems and concepts, such
as Internet of Things (IoT) and Cyber Physical Systems (CPS),
to ensure common technical grounding and architectural
principles. Though, there is still a need to address the higherlevel
requirements of smart city as a complete ecosystem. To
this end, this paper discusses different Smart City solutions
and highlights lifecycle based modeling to better integrate
people, processes, and systems; and assure information
consistency, traceability, and long-term archiving.
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 represent
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.