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The Resource Description Framework (RDF) is the basic standard for representing information in the Semantic Web. It is mainly designed to be machine-readable and -processable. This paper takes the opposite side of view: RDF is investigated as a logic system designed for the needs of humans. RDF is developed as a logic system based on mathematical graphs, i.e., as diagrammatic reasoning system. As such, is has humanly-readable, diagrammatic representations. Moreover, a sound and complete calculus is provided. Its rules are suited to act on the diagrammatic representations. Finally, some normalforms for the graphs are introduced, and the calculus is modified to suit them. [ABSTRACT FROM AUTHOR]

In a distributed environment, authorizations are usually physically stored in several computers connected by a network. Each computer may have its own local policies which could conflict with the others. Therefore how to make a global decision from the local authorization policies is a crucial and practical problem for a distributed system. In this paper, three general integration models based on the degrees of node autonomy are proposed, and different strategies of integrating the local policies into the global policies in each model are systematically discussed. The discussion is based on the weighted authorization graph model that we proposed before. Keywords: access control, authorization conflict, weighted graph. [ABSTRACT FROM AUTHOR]

Content-based filtering can reflect content information, and provide recommendations by comparing various feature based information regarding an item. However, this method suffers from the shortcomings of superficial content analysis, the special recommendation trend, and varying accuracy of predictions, which relies on the learning method. In order to resolve these problems, this paper presents content-based image filtering, seamlessly combining content-based filtering and image-based filtering for recommendation. Filtering techniques are combined in a weighted mix, in order to achieve excellent results. In order to evaluate the performance of the proposed method, this study uses the EachMovie dataset, and is compared with the performance of previous recommendation studies. The results have demonstrated that the proposed method significantly outperforms previous methods. [ABSTRACT FROM AUTHOR]

Medical guidelines are clinical behaviour recommendations used to help and support physicians in the definition of the most appropriate diagnosis and/or therapy within determinate clinical circumstances. Due to the intrinsic complexity of such guidelines, their application is not a trivial task; hence it is important to verify if health-care workers behave in a conform manner w.r.t. the intended model, and to evaluate how much their behaviour differs. In this paper we present the GPROVE framework that we are developing within a regional project to describe medical guidelines in a visual way and to automatically perform the conformance verification. [ABSTRACT FROM AUTHOR]

This paper presents a semantics-driven web portal allowing browsing and flexible querying state-of-the-art data on organizations, national and international projects, current research topics, technologies and software solutions in the domain of the European Research in the FP6/IST program. The backbone of this portal consists of an ontology-based knowledge base structuring information about the above-described area. The portal incorporates advanced information retrieval methods, based on ontologies and on natural language processing. [ABSTRACT FROM AUTHOR]

This paper introduces a kernel selection method to automatically choose the best kernel type for a query by using the score distributions of the relevant and non-relevant images given by user as feedback. When applied to our data, the method selects the same best kernel (out of the 12 tried kernels) for a particular query as the kernel obtained from our extensive experimental results. [ABSTRACT FROM AUTHOR]

Multiple UAV cooperative reconnaissance is one of the most important aspects of UAV operations. This paper presents a genetic algorithm(GA) based approach for multiple UAVs cooperative reconnaissance mission planning problem. The objective is to conduct reconnaissance on a set of targets within predefined time windows at minimum cost, while satisfying the reconnaissance resolution demands of the targets, and without violating the maximum travel time for each UAV. A mathematical formulation is presented for the problem, taking the targets reconnaissance resolution demands and time windows constraints into account, which are always ignored in previous approaches. Then a GA based approach is put forward to resolve the problem. Our GA implementation uses integer string as the chromosome representation, and incorporates novel evolutionary operators, including a subsequence crossover operator and a forward insertion mutation operator. Finally the simulation results show the efficiency of our algorithm. [ABSTRACT FROM AUTHOR]

The development of intelligent multi-agent systems involves a number of concerns, including mobility, context-awareness, reasoning and mining. Towards ubiquitous intelligence this area of research addresses the intersection between mobile agents, heterogeneous networks, and ubiquitous intelligence. This paper presents a development of hardware and software systems to address the combination of these interests as Location-Aware Service. Our architecture performs the intelligent services to meet the respective requirements. By adding autonomous mobility to the agents, the system becomes more able to dynamically localize around areas of interest and adapt to changes in the ubiquitous intelligence landscape. We also analyze some lessons learned based on our experience in using location-aware multi-agent techniques and methods. Keywords: ubiquitous networks, location-awareness, multi-agent, context aware system, Ontology, smart home, pervasive computing. [ABSTRACT FROM AUTHOR]

Formal Concept Analysis is an unsupervised machine learning technique that has successfully been applied to document organisation by considering documents as objects and keywords as attributes. The basic algorithms of Formal Concept Analysis then allow an intelligent information retrieval system to cluster documents according to keyword views. This paper investigates the scalability of this idea. In particular we present the results of applying spatial data structures to large datasets in formal concept analysis. Our experiments are motivated by the application of the Formal Concept Analysis idea of a virtual filesystem [11,17,15]. In particular the libferris [1] Semantic File System. This paper presents customizations to an RD-Tree Generalized Index Search Tree based index structure to better support the application of Formal Concept Analysis to large data sources. [ABSTRACT FROM AUTHOR]

Text search engines are inadequate for indexing and searching XML documents because they ignore metadata and aggregation structure implicit in the XML documents. On the other hand, the query languages supported by specialized XML search engines are very complex. In this paper, we present a simple yet flexible query language, and develop its semantics to enable intuitively appealing extraction of relevant fragments of information while simultaneously falling back on retrieval through plain text search if necessary. We also present a simple yet robust relevance ranking for heterogeneous document-centric XML. [ABSTRACT FROM AUTHOR]

In this paper, we present the ${\mathcal{S}}$CIFF platform for multi-agent systems. The platform is based on Abductive Logic Programming, with a uniform language for specifying agent policies and interaction protocols. A significant advantage of the computational logic foundation of the ${\mathcal{S}}$CIFF framework is that the declarative specifications of agent policies and interaction protocols can be used directly, at runtime, as the programs for the agent instances and for the verification of compliance. We also provide a definition of conformance of an agent policy to an interaction protocol (i.e., a property that guarantees that an agent will comply to a given protocol) and a operational procedure to test conformance. [ABSTRACT FROM AUTHOR]

The search for an optimal node elimination sequence for the triangulation of Bayesian networks is an NP-hard problem. In this paper, a new method, called the TAGA algorithm, is proposed to search for the optimal node elimination sequence. TAGA adjusts the probabilities of crossover and mutation operators by itself, and provides an adaptive ranking-based selection operator that adjusts the pressure of selection according to the evolution of the population. Therefore the algorithm not only maintains the diversity of the population and avoids premature convergence, but also improves on-line and off-line performances. Experimental results show that the TAGA algorithm outperforms a simple genetic algorithm, an existing adaptive genetic algorithm, and simulated annealing on three Bayesian networks. [ABSTRACT FROM AUTHOR]

This paper illustrates our work concerning the development of an agent-based architecture for the control of a smart home environment. In particular, we focus the description on a particular component of the system: the Butler Interactor Agent (BIA). BIA has the role of mediating between the agents controlling environment devices and the user. As any good butler, it is able to observe and learn about users preferences but it leaves to its "owner" the last word on critical decisions. This is possible by employing user and context modeling techniques in order to provide a dynamic adaptation of the interaction with the environment according to the vision of ambient intelligence. Moreover, in order to support trust, this agent is able to adapt its autonomy on the basis of the received user delegation. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of training a discriminative classifier when the data sets are imbalanced. More specifically, this work is concerned with the problem of classify a sample as belonging, or not, to a Target Class (TC), when the number of examples from the "Non-Target Class" (NTC) is much higher than those of the TC. The effectiveness of the heuristic method called Non Target Incremental Learning (NTIL) in the task of extracting, from the pool of NTC representatives, the most discriminant training subset with regard to the TC, has been proved when an Artificial Neural Network is used as classifier (ISMIS 2003). In this paper the effectiveness of this method is also shown for Support Vector Machines. [ABSTRACT FROM AUTHOR]

In the paper, a new method for cost-sensitive learning of decision trees is proposed. Our approach consists in extending the existing evolutionary algorithm (EA) for global induction of decision trees. In contrast to the classical top-down methods, our system searches for the whole tree at the moment. We propose a new fitness function which allows the algorithm to minimize expected cost of classification defined as a sum of misclassification cost and cost of the tests. The remaining components of EA i.e. the representation of solutions and the specialized genetic search operators are not changed. The proposed method is experimentally validated and preliminary results show that the global approach is able to effectively induce cost-sensitive decision trees. [ABSTRACT FROM AUTHOR]

A successful adoption and adaptation of the particle swarm optimization (PSO) algorithm is presented in this paper. It improves the performance of Support Vector Machine (SVM) in the classification of incipient faults of power transformers. A PSO-based encoding technique is developed to improve the accuracy of classification. The proposed scheme is capable of removing misleading input features and, optimizing the kernel parameters at the same time. Experiments on real operational data had demonstrated the effectiveness and efficiency of the proposed approach. The power system industry can benefit from our system in both the accelerated operational speed and the improved accuracy in the classification of incipient faults. Keywords: particle swarm optimization, incipient fault, classification. [ABSTRACT FROM AUTHOR]

This paper proposes decision fusion method of shape and motion information based on Bayesian framework for object classification in image sequences. This method is designed for intelligent information and surveillance guard robots to detect and track a suspicious person and vehicle within a security region. For reliable and stable classification of targets, multiple invariant feature vectors to more certainly discriminate between targets are required. To do this, shape and motion information are extracted using Fourier descriptor, gradients, and motion feature variation on spatial and temporal images, and then local decisions are performed respectively. Finally, global decision is done using decision fusion method based on Bayesian framework. The experimental results on the different test sequences showed that the proposed method obtained good classification result than any other ones using neural net and other fusion methods. [ABSTRACT FROM AUTHOR]

Efficient multi-receiver delivery of video data over computer networks, such as the Internet is still challenging, due to heterogeneity in involved network technologies, end-node capabilities and receiver preferences. While adaptive and scalable video encoding can solve many of the problems caused by heterogeneity, media gateway systems are needed for performing video filtering and transformation in order to handle cases not solved by scalable coding. The complexity of such systems makes them difficult to manage by humans. Hence streaming media delivery systems, including media gateway systems should be self-managed only guided by policies provided by system managers and users. In this paper, we describe a media gateway systems framework for developing binding managers for gateway-based stream bindings. These bindings construct an overlay network for media stream distribution. The framework is open, enabling insertion of specific binding policies that suits particular user preferences. Our framework contributes towards self-management of multi-user streaming services by supporting self-configuration and re-configuration of multi-receiver bindings. It also contributes to easier development of business streaming applications by supporting the plugging in of binding policies targeting particular application domains. We describe the implementation of a prototype of the framework and evaluate the framework by observing and comparing the effect on the property of bindings when different binding policies are applied. Finally we discuss issues of gateway service placement when bindings are deployed in a large scale infrastructure. [ABSTRACT FROM AUTHOR]

Nowadays, distributed and mobile systems are acquiring greater importance and becoming more widely used to support ubiquitous computing. However, developing systems of this kind is a difficult task. Instead of concentrating on how problems should be solved developers must worry about implementation details. Ambient Calculus is a formalism that provides primitives to describe mobile systems in an abstract way. Aspect-oriented software development and software architectures promise to achieve reusability, maintenance and adaptability, which are all essential for the development of distributed systems. In this paper, we present how a platform-independent model called Ambient-PRISMA combines both Ambient Calculus and Aspect-Oriented Software Architecture for the specification of distributed and mobile systems. A platform-specific model in .Net for supporting Ambient-PRISMA code generation is also presented. [ABSTRACT FROM AUTHOR]

This paper presents a framework for building and managing compound documents in distributed systems. It enables an enriched document to be dynamically and nestedly composed of software components corresponding to various types of content, e.g., text, images, and windows. It permits the content of each component and program code to access the content inseparable inside the components so that the components can be viewed or modified without the need for any applications. It enables each component or document to migrate over a network under its own control by using mobile agent technology. Moreover, it introduces components as carriers or forwarders because it enables them to carry or transmit other components as first class objects to other locations. It offers several basic operations for network processing, e.g., forwarding, duplication, and synchronization. Since these operations are still document components, they can be dynamically deployed and customized at local or remote computers through GUI manipulations. It therefore allows an end-user to easily and rapidly configure network processing in the same way as if he/she had edited the documents. This paper describes the framework and its implementation, which currently uses Java as the implementation language as well as a component development language, and then illustrates several interesting applications that demonstrate its utility and flexibility. [ABSTRACT FROM AUTHOR]

In this paper we introduce the concept of Distributed Abstract Data Type (dadt), a new programming model simplifying the development of distributed, context-aware applications. A dadt instance logically encapsulates a collection of adt instances distributed throughout the system. dadt operations specify the semantics of access to this distributed state by using dedicated programming constructs. The scope of these operations can be restricted using dadtviews, i.e., projections over the target adt instances, defined declaratively and dynamically based on adt properties. Interestingly, dadt constructs can be used to deal not only with application data, but also with the space where it resides. This leads to a uniform treatment of the data and space concerns, simplifying the development of context-aware applications and providing the programmer with considerable flexibility and expressive power. We argue that dadts are amenable to incorporation in existing object-oriented programming languages, as demonstrated by our prototype implementation. [ABSTRACT FROM AUTHOR]

Since many human activities depend on the creation, use and transmission of symbolic information advances in our ability to produce and use such information (semi)automatically can be expected to have great impact on society and economic development. For this reason, this objective has been proposed as one of the main activities under Framework programme 7 (FP7), the next cycle of EU research and development activities and funding to run through 2007-2013. This paper gives a broad overview of the place of content and knowledge in FP7 and discusses several specific lines of research that have been identified as particularly important and promising. [ABSTRACT FROM AUTHOR]

With the adoption of Web services technology to realize Service Oriented Architectures, the need arises for more flexible and dynamic technologies for the just-in-time integration and composition of services. As the runtime integration, selection and management of services involves a variety of crosscutting concerns, such as error handling, service monitoring, and QoS enforcements, Aspect Oriented Programming (AOP) is useful to modularize such concerns. In this paper we investigate aspect-oriented support for crosscutting concerns of distributed management of web service compositions. We propose to use a distributed AOP approach, Aspects with Explicit Distribution (AWED), to modularize such concerns in a distributed variant of the Web Services Management Layer (WSML). Concretely, we present three contributions. First, we present an extension of the WSML to distributed compositions. Second, we present two extensions to AWED's aspect language which are useful for the modularization of crosscutting concerns of web services: support for chains of (a)synchronous remote advice that communicate through futures, and support for different modes of parameter passing between remote pointcuts and advice. Third, we illustrate our approach by investigating error handling in distributed web compositions. [ABSTRACT FROM AUTHOR]

From the computational point of view, Content-based Im- age Retrieval systems are potentially expensive and have user response times growing with the ever-increasing sizes of the databases associated to them. This paper presents a grid implementation of a Content-based Image Retrieval system that offers a good cost/performance ratio to solve this problem due to their excellent flexibility, scalability and fault tolerance. This approach allows a dynamic management of specific data- bases that can be incorporated to or removed from the CBIR system in function of the desired user query. Experimental performance results are collected in order to show the feasibility of this solution. [ABSTRACT FROM AUTHOR]

Deployment of distributed applications on large systems, and especially on grid infrastructures, becomes a more and more complex task. Grid users spend a lot of time to prepare, install and configure middleware and application binaries on nodes, and eventually start their applications. The problem is that the deployment process is composed of many heterogeneous tasks that have to be orchestrated in a specific correct order. As a consequence, the automatization of the deployment process is currently very difficult to reach. To address this problem, we propose in this paper a generic deployment framework allowing to automatize the execution of heterogeneous tasks composing the whole deployment process. Our approach is based on a reification as software components of all required deployment mechanisms or existing tools. Grid users only have to describe the configuration to deploy in a simple natural language instead of programming or scripting how the deployment process is executed. As a toy example, this framework is used to deploy CORBA component-based applications and OpenCCM middleware on one thousand nodes of the French Grid5000 infrastructure. Keywords: Grid computing, middleware, distributed applications, deployment, software components. [ABSTRACT FROM AUTHOR]

Globus Toolkit version 4 (GT4) provides a set of new services and tools, completing a first step towards the migration to web services of previous Globus Toolkit versions. It provides components addressing basic issues related to security, resource discovery, data movement and management, etc. However, it still lacks from advanced management frameworks that may be linked to GT4 services and thus providing a system-wide view of these services. This is especially true in the case of security related services. They need to be properly managed all across different organizations collaborating in the grid infrastructure. This paper presents the major achievements when designing and developing a semantic-aware management framework for GT4 security services. Keywords: GT4 security services management, web service-oriented management, semantic-aware policy checking and validation. [ABSTRACT FROM AUTHOR]

Grid workflows are very often composed of multilingual applications. Monitoring such multilingual workflows in the Grid requires an instrumentation infrastructure that is capable of dealing with workflow components implemented in different programming languages. Moreover, Grid workflows introduce multiple levels of abstraction and all levels must be taken into account in order to understand the performance behaviour of a workflow. As a result, any instrumentation infrastructure for Grid workflows should assist the user/tool to conduct the monitoring and analysis at multiple levels of abstraction. This paper presents a novel instrumentation infrastructure for Grid services that addresses the above-mentioned issues by supporting the instrumentation of multilingual Grid workflows at multiple levels of abstraction using a unified, highly interoperable interface. Keywords: grid, monitoring, instrumentation, legacy applications. [ABSTRACT FROM AUTHOR]

The paper describes a self-operating integration mechanism for virtual repository's distributed resources based on object-oriented databases in a grid architecture. The core architecture is based on the SBA theory and its virtual updateable views. Our virtual repository transparently processes heterogeneous data producing conceptually and semantically coherent results. Our integration apparatus is explained by two examples with different types of fragmentations - horizontal and vertical. A transparent integration process exploits a global index mechanism and an independent virtual P2P network for a communication between distributed databases. Researches presented in the paper are based on a prototype integrator which is currently under development. [ABSTRACT FROM AUTHOR]

TEDDY applications form a distributed package designed for data acquisition and evaluation of inspections carried out in nuclear power plants. These inspections typically involve a number of acquisition equipments exploring the state of different parts of the plant in order to detect any kind of failure. Currently, these applications follow a typical client-server model, where every client -up to one hundred- accesses a central server containing all the information about the inspection itself; furthermore, it centralizes all the coordination and synchronization mechanisms of the work. The client applications act as producer/consumer from server data, so that a failure in the server should halt all the activity in the inspection. In this paper, we propose a peer to peer model where all the nodes share the information and discuss the pros and cons of the new system. Keywords: Peer-to-peer, resource sharing, distributed applications, failure tolerance, replication, collaboration technologies. [ABSTRACT FROM AUTHOR]

The development of complex applications that use the Peer-to-Peer computing model is restrained by security and trust management concerns, despite evident performance benefits. An example of such an application of P2P computing is P2P Massive Multi-user Online Games, where cheating by players is simple without centralized control or specialized trust management mechanisms. The article presents new techniques for trust enforcement that use cryptographic methods and are adapted to the dynamic membership and resources of P2P systems. The proposed approach to trust management differs significantly from previous work in the area that mainly used reputation. The paper describes a comprehensive trust management infrastructure fore P2P MMO games that enables to recognize and exclude cheating players while keeping the performance overhead as low as possible. While the architecture requires trusted centralized components (superpeers), their role in trust management is limited to a minimum and the performance gains of using the P2P computing model are preserved. [ABSTRACT FROM AUTHOR]

This paper outlines the first experiences of an approach for automatically deriving information demands in order to provide users with demand-driven information supply and decision support. The presented approach is based on the idea that information demands with respect to work activities can be identified by examining the contexts in which they exist and that a suitable source for such contexts are Enterprise Models. However, deriving contexts manually from large and complex models is very time consuming and it is therefore proposed that a better approach is to, based on an Enterprise Model, produce a domain ontology and from this then automatically derive the information demand contexts that exist in the model. Keywords: information demand;enterprise model; ontology engineering; ontology management; context; context derivation. [ABSTRACT FROM AUTHOR]

The paper proposes a framework to assess the semantic similarity among instances within an ontology. It aims to define a sensitive measurement of semantic similarity, which takes into account different hints hidden in the ontology definition and explicitly considers the application context. The similarity measurement is computed by combining and extending existing similarity measures and tailoring them according to the criteria induced by the context. Experiments and evaluation of the similarity assessment are provided. [ABSTRACT FROM AUTHOR]

In this paper we present a multi-agent system aiming at supporting patients to search health care services of their interest in an e-health scenario. The proposed system is HL7-aware in that it represents both patient and service information according to the directives of HL7, the information management standard adopted in medical context. In this paper we illustrate the technical characteristics of our system and we present a comparison between it and other related systems already proposed in the literature. [ABSTRACT FROM AUTHOR]

In this paper, we present a web-based, machine-learning enhanced news reader (PersoNews). The main advantages of PersoNews are the aggregation of many different news sources, machine learning filtering offering personalization not only per user but also for every feed a user is subscribed to, and finally the ability for every user to watch a more abstracted topic of interest by employing a simple form of semantic filtering through a taxonomy of topics. [ABSTRACT FROM AUTHOR]

Recently, the advantages of metamodeling for the graphical specification of ontologies have been recognized by the semantic web community. This has lead to a number of activities concerned with the development of graphical modeling approaches for the Web Ontology Language based on the Meta Object Facility (MOF) and the Unified Modeling Language (UML). An aspect that has not been addressed so far is the need to specify mappings between heterogenous ontologies. With an increasing number of ontologies being available, the problem of specifying mappings is becoming more important and the rationales for providing model based graphical modeling support for mappings is the same as for the ontologies themselves. In this paper, we therefore propose a MOF-based metamodel for mappings between OWL DL ontologies. [ABSTRACT FROM AUTHOR]

This paper presents a new ontology mapping method. This method addresses the case in which a non-structured ontology is to be mapped with a structured one. Both ontologies are composed of triplets of the form (object, characteristic, value). Structured means that the values describing the objects according to a given characteristic are hierarchically organized using the a kind of relation. The proposed method uses fuzzy conceptual graphs [8] to represent and map objects from a source ontology to a target one. First, we establish a correspondence between characteristics of the source ontology and characteristics of the target ontology based on the comparison of their associated values. Then, we propose an original way of translating the description of an object of the source ontology using characteristics and values of the target ontology. The description thus translated is represented as a fuzzy conceptual graph. Finally, a new projection operation is used to find mappings between translated objects and actual objects of the target ontology. This method has been implemented and the results of an experimentation concerning the mapping of ontologies in the field of risk in food are presented. [ABSTRACT FROM AUTHOR]

This paper outlines a prototypical work bench which offers semantically enhanced analytical capabilities to the business analyst. The business case for such an environment is outlined and user scenario development used to illustrate system requirements. Based upon ideas from meta-discourse and exploiting advances within the fields of ontology engineering, annotation, natural language processing and personal knowledge management, the Analyst Work Bench offers the automated identification of, and between business discourse items with possible propositional content. The semantically annotated results are visually presented allowing personalised report path traversal marked up against the original source. [ABSTRACT FROM AUTHOR]

Workflow management systems usually interpret a workflow definition rigidly, allowing no deviations during execution. However, there are real life situations where users should be allowed to deviate from the prescribed static workflow definition for various reasons, including lack of information about parameter values and unavailability of the required resources. To flexibilize workflow execution, this paper proposes an exception handling mechanism that allows the execution to proceed when otherwise it would have been stopped. The proposal is introduced as a set of extensions to OWL-S that capture the information required for the flexibilization mechanism. In particular, this paper focus on the transactional behavior of a workflow instance, in the sense that it guarantees that either all actions executed by the instance terminate correctly or they are all abandoned. [ABSTRACT FROM AUTHOR]

Ontologies are instruments for capturing and using formal semantics, and are often the result of a "central committee controlled" style of working. A new trend on the Web is the increasing popularity of folksologies in the form of social bookmarking sites. Folksologies provide informal semantics and can be created and adopted by anybody anytime anywhere on the Internet. Shared meaning in a folksology emerges through the use of tags that are used to bookmark web pages, their usage frequency being considered a reliable indicator of their usefulness and acceptance. Rather than choosing for either ontologies or folksologies, hybrid emergent semantics systems are needed that combine elements of both perspectives, depending on the particular application. There is a need to analyse the larger picture (including the full range of semantics' functionalities in their context of use. In this paper, we outline a number of key design characteristics of emergent semantics systems (ESS). We examine the functionalities of two existing examples of well-known ESSs: del.icio.us and Piggy Bank. Using the results of this comparison, we introduce DogmaBank as a proof of concept implementation of a next-generation ESS that introduces a more advanced combination of lexical and conceptual emergent semantics functionalities. [ABSTRACT FROM AUTHOR]

Nowadays, ontologies are used in several research domains by offering the means to describe and represent concepts of information sources. Therefore, several approaches and systems storing ontologies and their instances in the same repository (database) have been proposed. As a consequence, defining a query language to support ontology-based database (OBDB) becomes a challenge for the database community. In this paper, we present OntoQL, an ontology query language for OBDBs. Firstly, we present formally the OBDB data model supported by this language. Secondly, an overview of the algebra defining the semantics of operators used in OntoQL is described. Several query examples showing the interest of this language compared to traditional database query languages are given along this paper. Finally, we present a prototype of the implementation of OntoQL. [ABSTRACT FROM AUTHOR]

The semantic web will not be a static collection of formats, data and meta-data but highly dynamic in each aspect. This paper proposes a personalized event notification system for semantic web documents (ENS-SW). The system can intelligently detect and filter changes in semantic web documents by exploiting the semantic structure of those documents. In our prototype, we combine the functionalities of user profiles and distributed authoring systems. Typically, both approaches would lack the ability to handle semantic web documents. This paper introduces the design and implementation of our event notification system for semantic web documents that handles the XML representation of RDF. We analyzed our prototype regarding accuracy and efficiency in change detection. Our system supports sophisticated change detection including partial deletion, awareness for document restructuring, and approximate filter matches. [ABSTRACT FROM AUTHOR]

At the early stages of the cooperative information system development one of the major problems is to explore the space of alternative ways of assignment and delegations of goals among system actors. The exploration process should be guided by a number of criteria to determine whether the adopted alternative is good-enough. This paper frames the problem of designing actor dependency networks as a multi-agent planning problem and adopts an off-the-shelf planner to offer a tool (P-Tool) that generates alternative actor dependency networks, and evaluates them in terms of metrics derived from Game Theory literature. As well, we offer preliminary experimental results on the scalability of the approach. [ABSTRACT FROM AUTHOR]

The growing need for information sharing among partnering organizations or members of virtual organizations poses a great security challenge. One of the key aspects of this challenge is deploying intrusion detection systems (IDS) that can operate in heterogeneous, large-scale environments. This is particularly difficult because the different networks involved generally use IDSs that have not been designed to work in a cooperative fashion. This paper presents a model for integrating intrusion detection systems in such environments. The main idea is to build compositions of IDSs that work as unified systems, using a service-oriented architecture (SOA) based on the Web Services technology. The necessary interoperability among the elements of the compositions is achieved through the use of standardized specifications, mainly those developed by IETF, W3C and OASIS . Dynamic compositions are supported through service orchestration. We also describe a prototype implementation of the proposed infrastructure and analyze some results obtained through experimentation with this prototype. [ABSTRACT FROM AUTHOR]

Trust models have been touted to facilitate cooperation among unknown entities. Existing behavior-based trust models typically include a fixed evaluation scheme to derive the trustworthiness of an entity from knowledge about its behavior in previous interactions. This paper in turn proposes a framework for behavior-based trust models for open environments with the following distinctive characteristic. Based on a relational representation of behavior-specific knowledge, we propose a trust-policy algebra allowing for the specification of a wide range of trust-evaluation schemes. A key observation is that the evaluation of the standing of an entity in the network of peers requires centrality indices, and we propose a first-class operator of our algebra for computation of centrality measures. This paper concludes with some preliminary performance experiments that confirm the viability of our approach. [ABSTRACT FROM AUTHOR]

Web services are becoming more and more complex, involving numerous interacting business objects within complex distributed processes. In order to fully explore Web service business opportunities, while ensuring a correct and reliable execution, analyzing and tracking Web services interactions will enable them to be well understood and controlled. The work described in this paper is a contribution to these issues for Web services based process applications. This article describes a novel way of applying process mining techniques to Web services logs in order to enable "Web service intelligence". Our work attempts to apply Web service log-based analysis and process mining techniques in order to provide semantical knowledge about the context of and the reasons for discrepancies between process models and related instances. [ABSTRACT FROM AUTHOR]

Users preferences heterogeneity in distributed systems often forces resources suppliers to offer customizable-resources in order to fulfill different customer needs. We present in this paper a Feature Logic based approach to customizable-resources description, selection, and composition. In our approach, resources and requests are both specified in a logical framework by feature terms. The feature terms unification technique allows reasoning on these specifications in order to select and possibly compose the resources that are candidate to satisfy a client request. [ABSTRACT FROM AUTHOR]

This paper presents the realisation, using a Service Oriented Architecture, of an approach for dynamic flexibility and evolution in workflows through the support of flexible work practices, based not on proprietary frameworks, but on accepted ideas of how people actually work. A set of principles have been derived from a sound theoretical base and applied to the development of worklets, an extensible repertoire of self-contained sub-processes aligned to each task, from which a dynamic runtime selection is made depending on the context of the particular work instance. [ABSTRACT FROM AUTHOR]

Although the efforts from the Workflow Management Coalition (WfMC) led to the definition of a standard process definition language (XPDL), there is still no standard for the definition of expected exceptions in workflows. Yet, the very few Workflow Management Systems (WfMC) capable of managing exceptions, provide a proprietary exception handling unit, preventing workflow exception definitions from being portable from one system to another one. In this paper, we show how generic process definitions based on XPDL can be seamlessly enriched with standard-conform exception handling constructs, starting from a high-level event-condition-action language. We further introduce a suitable rule compiler, enabling to yield portable process and exception definitions in a fully automated way. [ABSTRACT FROM AUTHOR]

Most available aspect-oriented languages today are extensions to programming languages. However, aspect-orientation, which is a paradigm for decomposition and modularization, is not only applicable in that context. In this paper, we introduce aspect-oriented software development concepts to workflow languages in order to improve the modularity of workflow process specifications with respect to crosscutting concerns and crosscutting changes. In fact, crosscutting concerns such as data validation and security cannot be captured in a modular way when using the constructs provided by current workflow languages. We will propose a concern-based decomposition of workflow process specifications and present the main concepts of aspect-oriented workflow languages using AO4BPEL, which is an aspect-oriented workflow language for Web Service composition. Keywords: Modularity, Separation of Concerns, Aspect-Oriented Software Development, Workflow Languages. [ABSTRACT FROM AUTHOR]

The interest surrounding the Web services (WS) composition issue has been growing tremendously. In the near future, it is awaited to prompt a veritable shift in the distributed computing history, by making the Service-Oriented Architecture (SOA) a reality. Yet, the way ahead is still long. A careful investigation of a major part of the solutions proposed so far reveals that they follow a workflow-like composition approach and that they view failures as exceptional situations that need not to be a primary concern. In this paper, we claim that obeying these assumptions in the WS realm may constrain critically the chances to achieve a high-dependability level and may hamper significantly flexibility. Motivated with these arguments, we propose a WS composition modeling approach that accepts failures inevitability and enriches the composition with concepts that can add flexibility and dependability but that are not part from the WS architecture pillars, namely, the state, the transactional behavior, the vitality degree, and the failure recovery. In addition, we describe a WS composition in terms of definition rules, composability rules, and ordering rules, and we introduce a graphical and a formal notation to ensure that a WS composition is easily and dynamically adaptable to best suit the requirements of a continuously changing environment. Our approach can be seen as a higher level of abstraction of many of the current solutions, since it extends them with the required support to achieve higher flexibility, dependability, and expressiveness power. [ABSTRACT FROM AUTHOR]