Abstract This paper sheds light on the complexity of designing Internet of Things (IoT) ecosystems where a high number of things reside and thus must collaborate despite their reduced size, restricted connectivity, and constrained storage limitations. To address this complexity, a novel concept referred to as thing artifact is devised abstracting the roles that things play in an IoT ecosystem. The abstraction focuses on 3 crosscutting aspects, namely functionality in terms of what to perform, life cycle in terms of how to behave, and interaction flow in terms of with whom to exchange. Building upon the concept of data artifact commonly used in data-driven business applications design, thing artifacts engage in relations with peers to coordinate their individual behaviors and hence avoid conflicts that could result from the quality of exchanged data. Putting functionality, life cycle, interaction flow, and relation together contributes to abstracting IoT ecosystems design. A system implementing a thing artifact-based ecosystem along with some experiments is presented in the paper as well.

Cloud consumers’ requirements possess an inherent dynamic nature, characterized by fluctuating needs in reliability and high-availability relative to their workload. To satisfy these requirements, service reconfiguration strategies are put in place ensuring first, adaptable service provisioning and second, compliance with the agreed-upon Service Level Agreements (SLAs) between consumers and providers. However, deviations between SLAs and “real” observed behaviours could occur even after triggering reconfiguration strategies. Additionally, as organizations increasingly embrace multi-cloud environments, careful consideration must be given to the inherent challenges that arise in this requirements satisfaction. In this paper, we represent these strategies as state machines used to report their conformance to collected logs which track what really happened at run-time. The collected logs are processed to construct state machines suitable for conformance checking. Experiments demonstrating the technical doability of using conformance checking to detect deviations between SLAs and logs, along with verifying the suitability of reconfiguration strategies, are also discussed in the paper.

Summary In the context of Internet of Things, thingsourcing is poised to promote the collective behavior that should prevail among things despite their independent nature being confined into silos. By analogy with crowdsourcing where crowds of (sometimes anonymous) people are contacted for their expertise, thingsourcing abstracts crowds of things and provides the necessary mechanisms for composing things together so they collectively satisfy users' demands. However, to ensure successful discovery of things according to these demands' requirements, an ontology‐based semantic description of things is deemed necessary. This article presents an approach for enriching things' descriptions semantically in preparation for their composition with respect to specific scripts that define who will do what, when, and where. A system demonstrating semantic thingsourcing along with a case study about dairy supply‐chain is presented in this article as well.

With great pleasure we welcome the delegates of the 19th IEEE Conference on Computer Systems and Applications (AICCSA'2022) that will be held on the campus of Zayed University in Abu-Dhabi, United Arab Emirates (UAE) from December 5 to 7, 2022. The essence of AICCSA in computer systems research remains strong, healthy, and vibrant, with an acceptance rate of 42%. AICCSA'2022 IEEE proceedings will publish the accepted authors' works on Xplore following the conference. AICCSA uses a double-blind review process whereby each submission undergoes a rigorous review process. The breadth of topics in the submitted papers reflects the scope of areas in which computer systems evolve.

International audience

International audience

Summary Despite the elasticity and pay‐per‐use benefits of cloud computing (aka fifth utility computing), organizations adopting clouds could be locked into single cloud providers, which is not always a “pleasant” experience when these providers stop operations. This is a serious concern for those organizations that who would like to deploy (core) business processes on the cloud along with tapping into these two benefits. To address the lock‐into concern, this paper proposes an approach for decomposing business processes into fragments that would run over multiple clouds and hence multiple providers. To develop fragments, the approach considers both restrictions over owners of business processes and potential competition among cloud providers. On the one hand, restrictions apply to each task in a business process and are specialized into budget to allocate, deadline to meet, and exclusivity to request. On the other hand, competition leads cloud providers to offer flexible pricing policies that would cater to the needs and requirements of each process owner. A policy handles certain clouds' properties referred to as limitedness, non‐renewability, and non‐shareability that impact the availability of cloud resources and hence the whole fragmentation. For instance, a non‐shareable resource could delay other processes should the current process do not release this resource on time. During fragmentation, interactions between owners of processes and providers of clouds happen according to two strategies referred to as global and partial. The former collects offers about cloud resources from all providers, while the latter collects such details from particular providers. To evaluate these strategies' pros and cons, a system implementing them, as well as demonstrating the technical feasibility of the fragmentation approach using credit‐application case study, is also presented in the paper. The system extends BPMN2‐modeler Eclipse plugin and supports interactions of processes' owners with clouds' providers that result to identifying the necessary fragments with focus on cost optimization.

We are delighted to present this novel special issue, which emphasizes semantic eSystems and their engineering methods, techniques, and tools. “eSystems” are those interdisciplinary cost-effective and interconnected solutions that leverage advanced information and communication technologies' techniques and tools to gain competitive advantage. Recent years have witnessed increasing interest in the design and development of various eSystem-based applications, ranging from real-world to machine and robotic applications. An essential feature in eSystems is their intelligent ability to “speak” and interact with one another to support function “extensibility” so that complex interactions could be established with other eSystems. Therefore, connecting disparate eSystems “on the fly” necessitates engineering a dialog channel such that it enables data fusion, exchange, and link in a unified and understandable way. While data emitted from eSystems are of different formats, sizes, and types, adopting semantic data technologies is a natural way to address these differences. Simply put, semantics is about agreeing on a common understanding of data that need to be exchanged between systems and between humans and systems. This special issue received 22 submissions, which were aligned with the theme of semantic eSystems' methods, techniques, and tools. Those submissions came from diverse researchers from academia, industry, and individuals from all over the globe. First, all submissions were screened closely by the editors to check their suitability with the special issue's list of topics. Second, after multiple rounds of peer review, only 11 high-quality submissions were accepted for publication in this special issue. Those accepted papers address the semantic eSystems theme from different perspectives including, for instance, efficient semantic–visual indexing model for large-scale image retrieval in cloud environment, trilateration-based indoor localization engineering technique for visible light communication system, graph-based system to enable efficient transformation of enterprise infrastructures, recognizing physical activities having complex interclass variations using semantic data of smartphone, spatiotemporal-based sentiment analysis on tweets for risk assessment of an event using the deep-learning approach, sentiment-based eSystem using hybridized fuzzy and deep neural network for measuring customer satisfaction, data fusion analysis for emotion recognition with thermal image and Internet of Thing devices, unified framework to manage cybersecurity and safety in manufacturing industry, graph-based convolutional neural network stock price prediction with leading indicators, author classification using transfer learning and predicting stars in coauthor networks, and DNA signal analysis tool: intelligent noise suppression window filter. The authors express their sincere thanks to the Editor-in-Chief for allowing them to organize this special issue. The editorial office staff members are excellent and are thanked for their support. The authors are also thankful to all the contributors who made this special issue possible and to the reviewers for their thoughtful contributions.

There have been significant advances in the field of Internet of Things (IoT) recently, which have not always considered security or data security concerns: A high degree of security is required when considering the sharing of medical data over networks. In most IoT-based systems, especially those within smart-homes and smart-cities, there is a bridging point (fog computing) between a sensor network and the Internet which often just performs basic functions such as translating between the protocols used in the Internet and sensor networks, as well as small amounts of data processing. The fog nodes can have useful knowledge and potential for constructive security and control over both the sensor network and the data transmitted over the Internet. Smart healthcare services utilise such networks of IoT systems. It is therefore vital that medical data emanating from IoT systems is highly secure, to prevent fraudulent use, whilst maintaining quality of service providing assured, verified and complete data. In this article, we examine the development of a Cognitive Fog (CF) model, for secure, smart healthcare services, that is able to make decisions such as opting-in and opting-out from running processes and invoking new processes when required, and providing security for the operational processes within the fog system. Overall, the proposed ensemble security model performed better in terms of Accuracy Rate, Detection Rate, and a lower False Positive Rate (standard intrusion detection measurements) than three base classifiers (K-NN, DBSCAN, and DT) using a standard security dataset (NSL-KDD).

Cloud services are often distributed across several data centers requiring new scalable approaches to efficiently perform searching to reduce the energy and price cost of fulfilling requests. Multiagent-based systems have arisen as a powerful technique for improving distributed processing on a wide scale, which can operate in environments where partial observability is the norm and the cost of prolonged search can be exponential. In this paper, we present a multiagent-based service composition approach, using agent-matchmakers and agent-representatives, for the efficient retrieval of distributed services and propagation of information within the agent network to reduce the amount of brute-force search. Our extensive simulation results indicate that by introducing localized agent-based memory searches, the amount of actions (with their associated energy costs) can be reduced by over 50 percent which results in a lower energy cost per composition request.

This paper discusses a novel way of making business processes and Internet of Things (IoT) work together. Indeed each "suffers" from many limitations that the other could help address them and vice versa. On the one hand, business processes are known for capturing organizations' best practices when satisfying users' demands but do not have the capabilities of controlling the physical surrounding that comprises millions of devices/things. On the other hand, IoT is known for provisioning contextualized services to users thanks to millions of devices/things but does not have the capabilities of making these devices/things collaborate. The paper presents a framework to support the collaboration of business processes and IoT. This collaboration is exemplified with 2 types of processes referred as thing-aware processes (TaP) and process-of-things (PoT). A system illustrating the development of PoT is presented in the paper as well.

In the Internet of Things (IoT), mutation aims to enhance functionality and survivability of a thing in the context of dynamic environments by allowing the thing to satisfy a need or seize a potential opportunity. In this paper, we propose a framework based on thing mutation as a countermeasure to certain security threats that could impact things' operations (e.g., sensing and communicating). We then provide a case study which focuses on battery draining attack and propose a mutation-based strategy as a countermeasure to this attack.

The Internet of Things (IoT) is among the latest Information and Communication Technologies (ICT) developments that is making the boundaries between reality and fiction vanish. According to Mark Weiser, "...The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it." [5]. The International Data Corporation (IDC) also mentions the huge spending on IoT that "...will increase by a compound annual growth rate of 13.6% from 2017 to 2022, reaching $1.2 trillion within the next four years"1. To sustain this rapid growth, IoT should overcome different obstacles such as diversity of things' development technologies and communication standards, users' reluctance and sometimes rejection due to things invading their privacy, lack of killer applications that demonstrate the necessity of things, lack of an IoT-oriented software engineering discipline, and finally, the passive nature of things. To address these obstacles, the research community is putting forward many solutions that would make things proactive and responsive to their cyber-physical surroundings. This should allow things for instance, to reach out to peers that expose collaborative behavior, to form dynamic alliances when necessary, to avoid peers that expose malicious behavior, and to be accountable for their actions. In this keynote presentation, we discuss our ongoing research agenda on IoT with focus on four initiatives: process-of-things [3], mutation-of-things [1], cloud-fog-things [2, 6], and finally, vetting-things [4].

Microservices have emerged as an alternative solution to many existing technologies allowing to break monolithic applications into “small” fine-grained, highly-cohesive, and loosely-coupled units. However, identifying microservices remains a challenge that could undermine this migration success. This paper proposes an approach for microservices automatic-identification from a set of business processes (BP). The approach is multi-models combining different independent models that represent a BP's control dependencies, data dependencies, semantic dependencies, respectively. the approach is also based on collaborative clustering. A case study about renting bikes is adopted to illustrate and demonstrate the approach. In term of precision, the results show how BPs as inputs permit to generate better microservices compared to other approaches discussed in the paper, as well.

This paper presents thingsourcing to enable thing collaboration in the context of IoT. Compared to crowdsourcing that refers to a crowd of persons, there is limited research in thingsourcing which deprives things from participating in complex business applications. In this paper, thingsourcing is associated with a platform that acts as an IoT marketplace where things sign-up and sign-off looking for opportunities to complete users' demands. The platform also has a set of mechanisms that allow to describe, search for, and “glue” things together. For demonstration purposes a car service center is used illustrating how things like service bays and vehicles collaborate in compliance with scripts defined in ComPOS (Composition language for Palcom Oblivious Services).

Summary This paper stresses out the struggle of organizations when managing multiple variants of the same business process. Each variant constitutes a response to structural and/or functional needs that overtime become unsustainable due to the multiplicity and complexity of these needs. To mitigate this struggle, a knowledge‐based approach for capturing these versions into a single configurable business process and splitting this process into fragments is discussed in the paper. The approach builds a configuration knowledge base to track the business process variability (ie, particularities of each business process variant). Variants are represented as a new configurable process structure tree resulting from fragmenting a business process. Implementation of the approach is, also, reported in this paper.

Social business processes support enterprises tap into the opportunities of Web 2.0. To ensure an efficient support, this paper presents an approach for identifying an enterprise’s business processes that could be converted into social. Indeed, not all processes are eligible for this conversion. The approach is built upon the concept of enterprise architecture that sheds the light on the necessary contextual elements for guiding the socialization of business processes. Due to the fuzzy nature of socialization, two multi-criteria decision making techniques, fuzzy logic and fuzzy-decision tree, enhance this guidance. A set of experiments for evaluating the proposed approach are presented in the paper, as well.

International audience

Abstract: This paper discusses the blend of cognitive computing with the Internet-of-Things that should result into developing cognitive things. Today’s things are confined into a data-supplier role, which deprives them from being the technology of choice for smart applications development. Cognitive computing is about reasoning, learning, explaining, acting, etc. In this paper, cognitive things’ features include functional and non-functional restrictions along with a 3 stage operation cycle that takes into account these restrictions during reasoning, adaptation, and learning. Some implementation details about cognitive things are included in this paper based on a water pipe case-study.

International audience

Despite the smooth weaving of the Internet-of-Things into people's daily lives, many challenges, such as diversity and multiplicity of things' development technologies and communication standards, and users' reluctance due to privacy invasion, are slowing down this weaving. This paper tackles the challenge of things' passive nature that has confined them into a data-supplier role. Empowering things with additional capabilities would make them proactive so, that, they can for instance, reach out to peers exposing collaborative attitude and (un)form dynamic communities when necessary. In this paper, this empowerment takes shape through thing agentification that relies on norms (specialized into business and social) to regulate the operations of things and commitments to ensure thing compliance with these norms. No-compliance would lead to sanctions over things, which should affect their credibility and reputation. A proof-of-concept and missing-child case study technically illustrate thing agentification.

In conjunction with the rapid growth and adoption of social media, people are more and more willing to share their personal experiences and opinions about products and/or services with the community. Opinions could be the basis of developing systems that would advise future users on how to proceed with any purchase without risking any disappointment. Unfortunately, opinions are not always genuine due to for instance, biased users as well as mixed feedback coming from the same users (i.e., multi-identity). This paper presents an approach for opinion analysis using credibility as a decisive criterion for supporting future users make sound decisions. The effectiveness of this approach has been tested using opinions posted on Twitter.

This paper presents an approach for detecting and tackling obstacles that could fail the execution of social business processes. Existing approaches target regular (nonsocial) business processes and thus, rely mainly on business logs that contain details such as who executes what, when, and where. However, interactions between a business process's three components namely task, machine, and person, are overlooked. This deprives process engineers from valuable details that could help detect and tackle obstacles. These details refer to task-2task, machine-2-machine, and person-2-person interactions and are recorded in social logs. Both business and social logs are part of an architecture that includes monitor, solver, and crawler components. A system implementing the architecture is also presented in the paper and illustrates how logs are developed and structured using eXtensible Event Stream format.

A configurable Business Process (BP) is an abstract BP that engineers customize with respect to specific requirements. To keep track of the multiple and recurrent customizations that lead to a set of derived BPs, this paper proposes a knowledge-based approach that uses a new Process Structure Tree called configurable PST (cPST). A cPST abstracts a separate variability option of the configurable BP. All cPSTs should be equivalent to the set of all PSTs associated with the derived BPs that could originate from the same configurable BP. This paper also proposes a logic-based configuration model for capturing configuration details on the cBP and describing the cPST computing.

A Social Business Process (SBP) is the result of blending social computing (a.k.a. Web 2.0) with business process (BP). Despite the benefits of SBP to enterprises, several limitations continue to undermine them. In this paper, we address two specific limitations, namely the difficulty of capturing SBP's requirements and the lack of a definition for SBP. Thus, meta-modeling is used to capture requirements from organizational, technological, and management perspectives. In addition, we introduce a definition for SBP by enriching an existing BP meta-model with social concepts. To annotate the SBP model with its requirements, a BPMN extension is proposed. The proposed meta-models are evaluated in terms of completeness and clarity using the Bunge-Wand-Weber ontology.

It is largely known that objective criteria like profit and market-share drive the decisions of engineering business processes. However, there are cases where subjective criteria (e.g., reputation and attitude) need also to be taken into account, which will definitely impact the objective criteria. These cases fall into examining business processes from a social perspective. This paper discusses the mechanisms of making a business process's components (task, person, and machine) exhibit certain social qualities like selfishness and goodwill. This exposure is dependent on three criteria that are resource availability, transactional properties of tasks, and profit. An online system demonstrates the use of these criteria when capturing and quantifying the social qualities in business processes.

This paper presents a system for tracking the execution of social actions over Facebook along with the execution of business tasks. Putting social actions like post and comment together, results into developing social flows. Webhooks is used to "listen" to the changes happening over Facebook pages. Keywords: Business Task, Facebook, Social Action, and Social Flow.

Over the years, different development waves have shaped the Web. Introduced as a tool to browse Web sites, the Web now is a dynamic and robust platform upon which enterprises conduct e-Business. One of these waves known as Web 2.0 (or social Web) is putting pressure on how enterprises should ensure a productive use of Web 2.0 applications such as Facebook and Twitter. Misuse cases of these applications are on the rise and the lack of guidelines and awareness is a main reason. This paper presents an approach for "controlling" the social actions that Web 2.0 applications allow users to execute. These actions are identified after analyzing some representative Web 2.0 applications and then defined in terms of stakeholders, content, and tools. The control over these actions is defined with UML Object Constraint Language (OCL) and then demonstrated through a prototype system.

This paper discusses how to design and develop collaborative enterprise applications using business and social artifacts. Business artifacts populate the business world (associated with business process management platforms) and allow to facilitate the communication between IT and non-IT practitioners over application requirements to satisfy, for example. And social artifacts populate the social world (associated with Web~2.0 applications) and abstract the online activities that are executed over Web~2.0 applications such as tagging photos. Both worlds are connected to each other through social machines that allow business artifacts to act upon Web~2.0 applications such as creating new social artifacts and checking on the statuses of existing social artifacts. A system that demonstrates business artifact and social artifact collaboration is also presented in this paper.

This paper looks into ways of supporting social Web services react to the behaviors that their peers expose at run time. Examples of behaviors include selfishness and unfairness. These reactions are associated with actions packaged into capabilities. A capability allows a social Web service to stop exchanging private details with a peer and/or to suspend collaborating with another peer, for example. The analysis of capability results into three types referred to as functional (what a social Web service does), non-functional (how a social Web service runs), and social (how a social Web service reacts to peers). To avoid cross-cutting concerns among these capabilities aspect-oriented programming is used for implementing a system.

Social Web Services (SWSs) constitute a novel paradigm of service-oriented computing, where Web services, just like humans, sign up in social networks that guarantee, e.g., better service discovery for users and faster replacement in case of service failures. In past work, composition of SWSs was mainly supported by specialised social networks of competitor services and cooperating ones. In this work, we continue this line of research, by proposing a novel SWSs composition procedure driven by the SWSs reputation. Making use of a well-known formal language and associated tools, we specify the composition steps and we prove that such reputation-driven approach assures better results in terms of the overall quality of service of the compositions, with respect to randomly selecting SWSs.

This paper presents a credibility model to assess trust of Web services. The model relies on consumers' ratings whose accuracy can be questioned due to different biases. A category of consumers known as strict are usually excluded from the process of reaching a majority consensus. We demonstrated that this exclusion should not be. The proposed model reduces the gap between these consumers' ratings and the current majority rating. Fuzzy clustering is used to compute consumers' credibility. To validate this model a set of experiments are carried out.

Data-driven Web services build on service-oriented technologies to provide an interoperable method of interacting with data sources on top of the Web. Data Web services composition has emerged as a flexible solution to answer users’ complex queries on the fly. However, as the number of Web services on the Web grows quickly, a large number of candidate compositions that would use different (most likely competing) services may be used to answer the same query. User preferences are a key factor that can be used to rank candidate services/compositions and retain only the best ones. In this article, we present a novel approach for computing the top- k data service compositions based on user preferences. In our approach, we model user preferences using fuzzy sets and incorporate them into the composition query. We use an efficient RDF query rewriting algorithm to determine the relevant services that may be used to answer the composition query. We match the (fuzzy) constraints of the relevant services to those of the query and determine their matching degrees using a set of matching methods. We then rank-order the candidate services based on a fuzzification of Pareto dominance and compute the top- k data service compositions. In addition, we introduce a new method for increasing the diversity of returned top- k compositions while maintaining as much as possible the compositions with the highest scores. Finally, we describe the architecture of our system and present a thorough experimental study of our proposed techniques and algorithms. The experimental study demonstrates the efficiency and the effectiveness of our techniques in different settings.

This paper discusses how social Web services are held responsible for the actions they take at run time. Compared to (regular) Web services, social Web services perform different actions, for instance establishing and maintaining networks of contacts and forming with some privileged contacts strong and long lasting collaborative groups. Assessing these actions' outcomes, to avoid any violation, occurs through commitments that the social Web services are required to bind to. Two types of commitments are identified: social commitments that guarantee the proper use of the social networks in which the social Web services sign up, and business commitments that guarantee the proper development of composite Web services in response to users' requests. Detecting commitment violation and action prohibition using monitoring results in imposing sanctions on the “guilty” social Web services and taking corrective actions. A system for commitment management in terms of definition, binding, monitoring, and violation detection is also discussed in this paper.

This paper discusses the value-added of diversity to support fault tolerant Web Services operation. Web Services offering the same functionality are gathering into the same virtual space referred to as diversity group. Besides the group additional components are used including: composite manager, group manager, and Web service manager. The first component invokes the diversity groups and either resumes or aborts the overall execution in case of failures. The second component oversees Web services execution and the interactions between them. Finally, the last component monitors a Web service execution and reports either failure or success to the group manager. An architecture and a set of experiments showing the use of diversity to design and deploy fault tolerant Web services is presented in this paper.

This paper discusses some of the research done in the area of communities of Web services. A community allows Web services offering similar functionalities to be grouped together. One challenge that arises as a result of this grouping concerns the assessment of the level of service of the community. We refer to this level of service as Quality of Community (QoC). The QoC is important as it permits differentiating the communities from each other as well as promoting and maintaining a certain service level in preparation for receiving user requests for processing. The QoC of a community is assessed based on the QoSs of the individual Web services that reside in this community. Different attributes specific to the community such as variance, selection rate, and substitution rate define the QoC. Experiments illustrating the use of the QoC are, also, reported in this paper.

Web services have become the technology of choice for service-oriented computing implementation, where Web services can be composed in response to some users' needs. It is critical to verify the compatibility of component Web services to ensure the correctness of the whole composition in which these components participate. Traditionally, two conditions need to be satisfied during the verification of compatibility: reachable termination and proper termination. Unfortunately, it is complex and time consuming to verify those two conditions. To reduce the complexity of this verification, we model Web services using colored Petri nets (PNs) so that a specific property of their structures is looked into, namely, well structuredness. We prove that only reachable termination needs to be satisfied when verifying behavioral compatibility among well-structured Web services. When a composition is declared as valid and in the case where one of its component Web services fails at run time, an alternative one with similar behavior needs to come into play as a substitute. Thus, it is important to develop effective approaches that permit one to analyze the similarity of Web services. Although many existing approaches utilize PNs to analyze behavioral compatibility, few of them explore further appropriate definitions of behavioral similarity and provide a user-friendly tool with automatic verification. In this paper, we introduce a formal definition of context-independent similarity and show that a Web service can be substituted by an alternative peer of similar behavior without intervening other Web services in the composition. Therefore, the cost of verifying service substitutability is largely reduced. We also provide an algorithm for the verification and implement it in a tool. Using the tool, the verification of behavioral similarity of Web services can be performed in an automatic way.

This paper presents an approach to developing Composite Web Services Marts (CWS-Marts). A CWS-Mart gathers ready-to-use composite Web services that users can invoke any time without going from scratch through the regular steps of discovering, selecting, and composing the necessary component Web services. In addition, this paper presents an architecture that encompasses four levels namely component, community, composite, and mart. The component and composite levels set respectively the ground upon which the community and mart levels are deployed. Similar to communities that gather similarly-functional Web services, CWS-Marts gather similarly-functional composite Web services. Some experimental details are, also, discussed in the paper.

International audience

Examining interactions between Web services is of paramount importance to the success of service composition. We have previously proposed a 2-layer framework for modeling, analyzing, and managing these interactions. Interactions are assigned to two layers: business logic and support. The business-logic layer comprises control and transactional flows, whereas the support layer comprises exception and message flows. This paper continues this research effort by focusing on the synchronization of the four flows at run-time. In particular, we discuss the synchronization mechanisms integrated into the 2-layer framework and report our preliminary experiments on the implementation.

This paper is an overview of how capacity-driven Web services are defined and put into action. Because of the specificities of these Web services compared to regular(i.e., mono-capacity) Web services, the way they are looked into is different and occurs through four steps known as description, discovery, composition, and enactment. A Web service that is empowered with several capacities, that are in fact operations to execute, has to know which capacity out of several it has to choose and then, trigger at run-time.For this purpose, this Web service takes into account the requirements like data and network that are put on each capacity it was empowered with. A feasibility discussion on the implementation of capacity-driven Web services is presented in this paper, as well.

In this paper, we discuss the suitability of using recommendation techniques for Web service discovery in distributed registry environments. The architecture we adopt consists in structuring registries of Web services into groups. We propose to adapt existing techniques for recommendation to ease the services discovery process. This consists of (1) recommendation of groups of registries using semantic matching and (2) recommendation of registries within these groups using user-characterization based technique. To put our proposed distributed registry architecture in practise and to test the efficiency of recommendation-based discovery, we propose to simulate a peer-to-peer (P2P) registries environment on top of JXTA platform.

Context-aware Web services are currently emerging as an important technology for building innovative context-aware applications. Unfortunately, context-aware Web services are still difficult to build. This paper describes ContextServ, a platform for rapid development of context-aware Web services. ContextServ adopts model-driven development where context-aware Web services are specified using ContextUML, a UML based modeling language. The platform also offers a set of automated tools for generating and deploying executable implementations of context-aware Web services. This paper presents the motivation, system design, implementation, and usage of ContextServ.

This paper focuses on the emerging importance of database and application security, textbooks and other supplementary materials to teach these topics and where to place these topics in a curriculum. The paper emphasizes 1) the growing concerns of database technologies and database applications, 2) existing books and supporting materials, and 3) and Zayed University's approach to teaching these topics. At Zayed, we incorporate database and database application security in two different courses.

Web service composition is currently a very focused-on topic of research, with many studies being proposed by academic and industrial research groups. This paper discusses the design and verification of behavior of composite Web services. We model composite Web services based on two behaviors, namely control and operational. These behaviors communicate through conversation messages. We use state charts to model composite Web services and verify the synchronization of the conversations among them using symbolic model checking with NuSMV.

Web services composition has been an active research area over the last few years. However, the technology is still not mature yet and several research issues need to be addressed. In this paper, we describe the design of CCAP, a system that provides tools for adaptive service composition and provisioning. We introduce a composition model where service context and exceptions are configurable to accommodate needs of different users. This allows for reusability of a service in different contexts and achieves a level of adaptiveness and contextualization without recoding and recompiling of the overall composed services. The execution semantics of the adaptive composite service is provided by an event-driven model. This execution model is based on Linda Tuple Spaces and supports real-time and asynchronous communication between services. Three core services, coordination service, context service, and event service, are implemented to automatically schedule and execute the component services, and adapt to user configured exceptions and contexts at run time. The proposed system provides an efficient and flexible support for specifying, deploying, and accessing adaptive composite services. We demonstrate the benefits of our system by conducting usability and performance studies.

This paper discusses how communities of Web services sustain the high availability of Web services engaged in composition scenarios. Availability is the proportion of time that a system is in a functioning condition. Web services offering the same functionality like HotelBooking are gathered into a single community regardless of who developed them, where they are located, and how they function. The current practice to achieve Web services high-availability advocates the use of replicas, which are managed according to specific replication strategies and come into play when the original Web service to back-up fails. Replacing Web services replicas with similarly functional Web services offers solutions to some of the limitations that feature these strategies, but at the same time raises other issues that are examined in this paper.

This paper presents a policy-based approach to compose Web services with emphasis on exceptions. Three types of policies denoted as engagement, mediation, and deployment regulate composition and are specified with WSPL. To support the exception handling strategy, context comes into play. Context oversees and keeps track of the execution outcomes of policies that took place and are now taking place.

This paper presents a Web services-based framework for modeling business-to-business (B2B) applications. This framework consists of three levels namely strategic, application, and resource, with focus here on the first two levels. The strategic level is about the common vision that independent businesses define as part of their decision to join forces. And the application level is about the business processes that get virtually integrated as result of this common vision. To implement the strategic and application levels, this paper leverages from our earlier two projects referred to as context-aware Web services and coordination model for Web services, respectively. Hence in line with these projects we model B2B applications as context-aware Web services. Context-based modeling is used for modeling and tracking interactions among B2B applications, with emphasis on how conflicts among the applications are identified and managed. The application of our framework to a B2B scenario relies on a case study from the purchasing domain. We also present a prototype implementation of our framework on this domain.

This paper presents a framework for modeling and deploying ℬusiness-to-ℬusiness (ℬ2ℬ) applications, with autonomous agents exposing the individual components that implement these applications. This framework consists of three levels identified by strategic, application, and resource, with focus here on the first two levels. The strategic level is about the common vision that independent businesses define as part of their decision of partnership. The application level is about the business processes that get virtually integrated as result of this common vision. Since conflicts are bound to arise among the independent applications/agents, the framework uses a formal model based upon computational argumentation theory through a persuasion protocol to detect and resolve these conflicts. In this protocol, agents can reason about partial information using partial arguments, partial attack and partial acceptability. Agents can then jointly find arguments supporting a new solution for their conflict, which is not known by any of them individually. Termination, soundness, and completeness properties of this protocol are presented. Distributed and centralized coordination strategies are also supported in this framework, which is illustrated with a simple online purchasing case study.

This write-up provides a summary of the International Workshop on Context enabled Source and Service Selection, Integration and Adaptation (CSSSIA 2008), organized in conjunction with WWW 2008, at Beijing, China on April 22nd 2008. We outline the motivation for organizing the workshop, briefly describe the organizational details and program of the workshop, and summarize each of the papers accepted by the workshop. More information about the workshop can be found at http://www.cs.adelaide.edu.au/~csssia08/.

This paper discusses how interactions between Web services engaged in composition scenarios are analyzed, modeled, and finally managed. Interactions are primarily considered as a means for conveying messages of different natures between separate components, for instance, Web services. To achieve better coordination and hence, avoid conflicts between Web services, in this paper interactions are handled by two layers known as business logic and support. The business-logic layer is the host of two flows known as control and transactional, whereas the support layer is the host of two additional flows namely exception and message. On top of the proposed layers and flows, context and policies are used to oversee the progress of interactions between Web services and to constrain the behavior of these Web services, respectively.

Making Web services context-aware is a challenge. This is like making Web service expose appropriate behaviors in response to changes detected in the environment. Context awareness requires a review and extension of the current execution model of Web services. This paper discusses the seamless combination of context and policy to manage behaviors that Web services expose during composition and in response to changes in the environment. For this purpose, a four-layer approach is devised. These layers are denoted by policy, user, Web service, and resource. In this approach, behavior management and binding are subject to executing policies of types permission, obligation, restriction, and dispensation. A prototype that illustrates how context and policy are woven into Web services composition scenarios is presented as well.

This paper presents a Web services composition approach that is built upon three layers known as component, community, and composite. The contribution of each layer towards this approach is assessed from two perspectives known as organization and management. Furthermore this paper discusses how Web services in a community are specialized into abstract and concrete. Interactions between abstract/- concrete Web services and composite Web services happen through a driver known as Open Service Connectivity. This driver permits first, binding any abstract Web service to any composite Web service and second, triggering any concrete Web service from any composite Web service.

This paper discusses the compatibility issue between policies of Web services, which could refrain the automatic composition of these Web services from smoothly progressing. Policies regulate/constrain the functioning of Web services at three levels identified by business, behavior, and privacy. Because independent Web services collaborate with one another in order to satisfy users' needs, their respective policies could be in contradiction. This could lead to conflicts and exceptions at run-time unless these contradictions are as a first step, detected and then, fixed. In this paper, WSPL is the language to specify policies of Web services.

Web services composition is a keystone in the development of interoperable systems. However, despite the widespread adoption of Web services, several obstacles still hinder their smooth automatic semantic reconciliation when being composed. Consistent understanding of data exchanged between composed Web services is hampered by various implicit modeling assumptions and representations. Our contribution in this article revolves around context and how it enriches data exchange between Web services. In particular, a context-based mediation approach to solve semantic heterogeneities between composed Web services is presented.

The explosion growth in the market place for handheld wireless devices has enabled new opportunities for wireless applications. Currently, handheld devices are restricted to being clients that make requests to servers and receive responses over the network. But as mobile ad-hoc networks become the trend, such devices will need to become active participants that serve requests from other devices and convey data to other devices as well. In this paper we present our vision of the future role that handheld devices will play in a mobile ad-hoc network configuration. We present this vision as part of the MESSENGER, project that develops data management mechanisms for UDDI registries of Web services using mobile users and their software agents, and then describe its extension for exchanging descriptions of Web services during ad-hoc collaboration sessions. User agents are in charge of interacting with peer users over an ad-hoc network, and collaborating on feeding UDDI registries with recent content

In this paper, we overviewed self-healing issues of Web services using AOP. This type of programming supports separation of self-healing concerns from Web services code and promotes maintenance and reusability. Similar to any computing application, Web services are subject to failure and unavailability due to multiple reasons, such as Web service faulty-code and unreliable communication-infrastructure

This paper presents an approach whose objective is to support Web services substitution. Substitution means replacing a component with another component, as long as the replacing component produces the same output and satisfies the same requirements as the replaced component. Motives for substitution include Web service's non-responsiveness to client requests and better arrangement with another, competitor Web service. To perform Web services substitution with less impact on the ongoing, and sometimes critical, business processes, the approach proposes deploying communities of Web services. A community promotes the dynamic binding of Web services through a common interface, known as open service connectivity. The open service connectivity directs requests to and responses from Web services regardless of how these latter are specified, implemented, and located

This paper discusses how ad-hoc collaboration boosts the operation of a set of messengers. This discussion continues the research we earlier initiated in theMESSENGER project, which develops data management mechanisms for UDDI registries of Web services using mobile users and software agents. In the current operation mode of messengers, descriptions of Web services are first, collected from UDDI registries and later on, distributed to other UDDI registries. This distribution mode of Web services descriptions does not foster the tremendous opportunities that both wireless technologies and mobile devices offer. When mobile devices are in the vicinity of each other, they can form a mobile ad-hoc network, which enables the exchange of data between these devices without any preexisting communication infrastructure. By authorizing messengers to engage in collaboration, collecting additional descriptions of Web services from other messengers can happen, too.

Summary form only given. This paper presents an approach for specifying an environment of software agents and Web services. Users in collaboration with software agents compose Web services into high-level business processes denoted by composite services. The participation of Web services in a composite service is based on several selection criteria such as the execution cost of a Web service and the location of the resources on which a Web service is performed. Prior to that selection, the specification approach puts forwards three levels: intrinsic, behavior, and organizational/functional.

Summary form only given. Centralized architectures based on the client server paradigm show their limits each time the Internet extends its capabilities. They present problems in terms of security, robustness, performance, high needs for administration. Short time solutions like load balancing and replication, or purchasing of more powerful hardware tend to cope with these limits for a while, but do not provide a definitive answer to these problems. Currently, different proprietary approaches hinder attempts to enabling communication between heterogeneous systems, while the Internet is developing toward a better interoperability with service-oriented architectures. Open source and standardization efforts allow building a framework providing an original answer to interoperability and scalability over the Internet. In this paper, we consider that the distributed nature of P2P platforms allied with the standardized WS architecture, based on SOAP and WSDL represent a powerful framework for building dynamic interoperable and decentralized information systems. The aim of our work is to allow P2P participants to dynamically access and compose semantic WS outside of the P2P network, and to improve existing WS publication and discovery by using the decentralization of P2P architecture. In order to achieve this goal, we propose a mediation framework built around the JXTA P2P architecture. This framework is based on the OWL-S language as a means for a semantic description of WS interfaces, in order to solve heterogeneity problems.

This paper presents an agent-based and context-oriented approach that supports the composition of Web services. A Web service is an accessible application that other applications and humans can discover and invoke to satisfy multiple needs. To reduce the complexity featuring the composition of Web services, two concepts are put forward, namely, software agent and context. A software agent is an autonomous entity that acts on behalf of users and the context is any relevant information that characterizes a situation. During the composition process, software agents engage in conversations with their peers to agree on the Web services that participate in this process. Conversations between agents take into account the execution context of the Web services. The security of the computing resources on which the Web services are executed constitutes another core component of the agent-based and context-oriented approach presented in this paper.

This work presents an approach for the dynamic management of the content of several Universal Description, Discovery, and Integration (UDDI) registries. By content, it is meant the announcements of Web services that providers post on various distributed UDDI registries. Unlike other initiatives in the field of Web services, our concerns are the following: availability of several UDDI registries, no predefined communication infrastructure between the UDDI registries, and no centralized component to coordinate the UDDI registries. The solution presented in this paper integrates users and software agents into what we call messengers. When a user is in the vicinity of an UDDI registry, his software agent, which resides in his mobile device, interacts with that registry. The objective is to submit the details on Web services that are stored in the mobile device.

Both workflow and agent technology have recently been applied to business process management. The integration of these two technologies definitely provides solutions to problems that cannot be solved by either of them individually. This paper summarises the capabilities of these two technologies and discusses the forms and benefits of integrating them for business process management. Generally, agent-enhanced workflow management and agent-based workflow management are the main forms of application of intelligent agents to workflow systems. Some research issues in each form are discussed. A conclusion, with a discussion about future research directions, is also given.

This paper presents a framework to deal with influence in multiagent systems. Influence is defined as the impact that a participant could have on another participant, known as target. Influence could be either positive or negative, according to how this target assesses the outcomes of the operations this participant has carried out. The presented framework could be viewed from two different perspectives: knowledge perspective with goal and belief as main components and organisation perspective with task and resource as main components.