223 research outputs found

    A User-Aware and Semantic Approach for Enterprise Search

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    This article describes how in addition to general purposes search engines, specialized search engines have appeared and have gained their part of the market. An enterprise search engine enables the search inside the enterprise information, mainly web pages but also other kinds of documents; the search is performed by people inside the enterprise or by customers. This article proposes an enterprise search engine called AMBIT-SE that relies on two enhancements: first, it is user-aware in the sense that it takes into consideration the profile of the users that perform the query; second, it exploits semantic techniques to consider not only exact matches but also synonyms and related terms. It performs two main activities: (1) information processing to analyse the documents and build the user profile and (2) search and retrieval to search for information that matches user’s query and profile. An experimental evaluation of the proposed approach is performed on different real websites, showing its benefits over other well-established approaches

    A Self-healing Architecture based on RAINBOW for Industrial Usage

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    Over recent decades computer and software systems become more and more complex because of the applications’ and user’s requirements. The complexity makes the software systems more vulnerable to the error and bugs. Also, environmental situations affect software systems which do not react to the environmental activities. Self-healing architectures have been proposed in order to make systems defeat these problems and to make systems capable of reacting to the environmental activity. Hence, these architectures help system to become dynamic and more robust, but finding a proper architecture which can support and cover system’s requirements is an issue. This is particularly true in industrial environments, which consist of some known and some unknown parameters. This paper presents an architecture that can be used in some industrial environment to facilitate the process of adapting the system to unpredicted situations. This architecture has been developed over the base of RAINBOW infrastructure and it is compliant to the MAPE control loop (Autonomic Computing control loop). The paper reports also about the practical experience of implementing this architecture for a painter robot in an automotive factory, which deals with problems in painted part by itself. The proposed architecture uses rule-based reasoning and it actualizes the method of environmental modeling by using a rule-based system as the model extractor. The results of the implementation shows huge benefits in reusability and even in the quality of painting process

    Patterns for self-adaptive systems: agent-based simulations

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    Self-adaptive systems are distributed computing systems that can adapt their behavior and structure to different kinds of conditions. This adaptation does not concern the single components only, but the entire system. In a previous work we have identified several patterns for self-adaptation, classifying them by means of a taxonomy, which aims at being a support for developers of self-adaptive systems. Starting from that theoretical work, we have simulated the described self-adaptation patterns, in order to better understand the concrete and real features of each pattern. The contribution of this paper is to report about the simulation work of three patterns as examples, detailing how it was carried out, in order to provide a further support for the developers

    The future of AOSE: exploiting SME for a new conception of methodologies

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    In the last years, the software engineering eld has provided developers with dierent methodologies to support their work. Nevertheless, existing methodologies can hardly meet the requirements of all existing scenarios, which are more and more complex and highly dierentiated. This problem can be faced by applying the Situational Method Engineering (SME) approach, which enables to build appropriate methodologies by composing \fragments" of existing ones. We envision this approach as the future of software engineering in general, and in particular if applied in Agent Oriented Software Engineering (AOSE). This approach has also the valuable advantage of reusing models, solutions, experiences and tools of existing and tested methodologies. In this paper we report three examples of application of the Situational Method Engineering approach in AOSE. We show that this approach can be applied following dierent directions, and in particular: entity-driven, metamodel-driven, and characteristic-driven. To concretely show these directions, we present three examples of methodologies for developing agent systems (one regarding self-organising systems), all constructed composing methodology fragments to meet the scenario requirements

    Injecting roles in Java agents through runtime bytecode manipulation

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    Agents are problem-solving entities that can be used to develop complex and distributed systems because they are autonomous, mobile, reactive, social, and proactive. Today's trends in agent technology include the development of applications as multi-agent systems, where several agents interact within the same application. In these systems, the interactions among agents must be carefully considered. Roles constitute a powerful paradigm for modeling interactions, allowing algorithmic issues and interaction-dependent issues to be handled independently. In this paper, we present the RoleX interaction infrastructure, which enables Java(TM) agents to dynamically assume and use roles at runtime. Our approach is based on using bytecode manipulation to add (or remove) Java members from agents, changing their capabilities. We detail the main component of RoleX, the Role Loader, which performs the bytecode manipulation that allows agents to dynamically assume and release roles

    Towards User-Aware Service Composition

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    Our everyday life is more and more supported by the information technology in general and specific services provided by means of our electronic devices. The AMBIT project (Algorithms and Models for Building context-dependent Information delivery Tools) aims at providing a support to develop services that are automatically tailored based on the user profile. However, while the adaptation of the single services is the first step, the next step is to achieve adaptation in the composition of different services. In this paper, we explore how services can be composed in a user-aware way, in order to decide the composition that better meets users’ requirements. That is, we exploit the user profile not only to provide her customized services, but also to compose them in a suitable way

    Building self-adaptive systems by adaptation patterns integrated into agent methodologies

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    Adopting patterns, i.e. reusable solutions to generic problems, turns out to be useful to rely on tested solutions and to avoid reinventing the wheel. To this aim, we proposed to use adaptation patterns to build systems that exhibit self-adaptive features. However, these patterns would be more usable if integrated in a methodology exploited to develop a system. In this paper we show how our Catalogue of adaptation patterns can be integrated into methodologies for adaptive systems; more in detail, we consider methodologies which support the development of multi-agent systems that can be considered good examples of adaptive systems. The paper, in particular, shows the integration of our Catalogue of adaptive patterns into the PASSI methodology, together with the graphical tool that we developed to support it

    Dynamic digital factories for agile supply chains: An architectural approach

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    Digital factories comprise a multi-layered integration of various activities along the factories and product lifecycles. A central aspect of a digital factory is that of enabling the product lifecycle stakeholders to collaborate through the use of software solutions. The digital factory thus expands outside the company boundaries and offers the opportunity to collaborate on business processes affecting the whole supply chain. This paper discusses an interoperability architecture for digital factories. To this end, it delves into the issue by analysing the key requirements for enabling a scalable factory architecture characterized by access to services, aggregation of data, and orchestration of production processes. Then, the paper revises the state-of-the-art w.r.t. these requirements and proposes an architectural framework conjugating features of both service-oriented and data-sharing architectures. The framework is exemplified through a case study

    Location-dependent services for mobile users

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    Abstract—One of the main issues in mobile services ’ research (M-service) is supporting M-service availability, regardless of the user’s context (physical location, device employed, etc.). However, most scenarios also require the enforcement of context-awareness, to dynamically adapt M-services depending on the context in which they are requested. In this paper, we focus on the problem of adapting M-services depending on the users ’ location, whether physical (in space) or logical (within a specific distributed group/application). To this end, we propose a framework to model users ’ location via a multiplicity of local and active service contexts. First, service contexts represent the mean to access to M-services available within a physical locality. This leads to an intrinsic dependency of M-service on the users’ physical location. Second, the execution of service contexts can be tuned depending on who is requesting what M-service. This enables adapting M-services to the logical location of users (e.g., a request can lead to different executions for users belonging to different groups/applications). The paper firstly describes the framework in general terms, showing how it can facilitate the design of distributed applications involving mobile users as well as mobile agents. Then, it shows how the MARS coordination middleware, implementing service contexts in terms of programmable tuple spaces, can be used to develop and deploy applications and M-services coherently with the above framework. A case study is introduced and discussed through the paper to clarify our approach and to show its effectiveness. Index Terms—Context-awareness, coordination infrastructures, M-services, mobility, multiagent systems. I

    Dealing with data and software interoperability issues in digital factories

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    The digital factory paradigm comprises a multi-layered integration of the information related to various activities along the factory and product lifecycle manufacturing related resources. A central aspect of a digital factory is that of enabling the product lifecycle stakeholders to collaborate through the use of software solutions. The digital factory thus expands outside the actual company boundaries and offers the opportunity for the business and its suppliers to collaborate on business processes that affect the whole supply chain. This paper discusses an interoperability architecture for digital factories. To this end, it delves into the issue by analysing the main challenges that must be addressed to support an integrated and scalable factory architecture characterized by access to services, aggregation of data, and orchestration of production processes. Then, it revises the state of the art in the light of these requirements and proposes a general architectural framework conjugating the most interesting features of serviceoriented architectures and data sharing architectures. The study is exemplified through a case study
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