P048 - ISTA 2004 - Information Systems Technology and its Applications
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- KonferenzbeitragPeriodic scheduling in on-demand broadcast system(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Prabhu, Nitin; Kumar, Vijay; Ray, IndrakshiRecent advances in mobile computing have enabled the deployment of broadcast based information systems such as, wireless internet, traffic information systems, etc. These systems are mainly pull-based and their performance very much depends on the broadcast schedule they use. In this paper we focus on on-demand broadcast system. We propose a new ondemand scheduling algorithm that takes scheduling decision at periodic interval, unlike previous algorithms that take decision after broadcasting every data item. This reduces the time client spends monitoring the broadcast channel for data items. We study its behavior with a detailed simulation study and show that our algorithm performs better than the pervious algorithms for on-demand systems.
- KonferenzbeitragCombining the best of global-as-view and local-as-view for data integration(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Xu, Li; Embley, David W.Currently, there are two main basic approaches to data integration: Globalas-View (GAV) and Local-as-View (LAV). However, both GAV and LAV have their limitations. In a GAV approach, changes in information sources or adding a new information source requires revisions of a global schema and mappings between the global schema and source schemas. In a LAV approach, automating query reformulation has exponential time complexity with respect to query and source schema definitions. To resolve these problems, we offer TIQS as an alternative point of view that is neither GAV nor LAV. The approach uses source-to-target mappings based on a predefined conceptual target schema, which is specified ontologically and independently of any of the sources. The proposed data integration system is easier to maintain than both GAV and LAV, and query reformulation reduces to rule unfolding. Compared with other data integration approaches, our approach combines the advantages of GAV and LAV, mitigates the disadvantages, and provides an alternative for flexible and scalable data integration.
- KonferenzbeitragAn access control service for dynamic and hierarchical resources: Declarative model and implementation on top of XACML(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Psaila, Giuseppe; Biondi, FulvioThe increasing complexity of (distributed) information systems requires new solutions for dealing with access control problems. In particular, information systems are based on a large number of resources, with very complex structure, that must be accessed by a large variety of users. Traditional and instance based solutions are not adequate. In this paper, we propose a new approach to the problem. First of all, we define an access control model which is declarative, modular, hierarchical and instance independent, so that it is suitable for highly dynamic contexts. Then, we reports about the implementation of a Profile Service, which effectively exploits the XACML technology to simplify and shorten the development.
- KonferenzbeitragTransM: A structured document transformation model(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Amaneddine, Nouhad; Bahsoun, Jean-Paul; Bodeveix, Jean-PaulWe present in this paper a transformation model for structured documents. TransM is a new model that deals with specified documents, where the structure conforms to a predefined data type. In particular TransM works on XML document conforming to a document type definition DTD. We present the different components of our model and we put the point on the kernel part of TransM which is the transformation rules. We show the strengths and the weaknesses of some recent transformation approaches and we prove that TransM can perform not only those simple and direct transformations but also complicated ones, especially, those who handle recursive appearance in the structure of the modeled documents, where elements may appear at any level of deepness in the hierarchical composition of the document structure, whilst the problem is not clearly resolved in the existing transformation models. We propose TransM as a general model for structured document transformation and we explore in more details its specification core that carries out document transformations.
- KonferenzbeitragA data transformation method based on schema mapping(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Li, You; Liu, Dongbo; Zhang, WwimingSchema mapping is an important approach to solve the problem of data integration. This paper introduces a research prototype called SDE, which is a system for managing and facilitating the complex tasks of heterogeneous data transformation and integration. We also present a data transformation method based on schema mapping techniques. By analyzing the mappings and schemas it can automatically fulfill the task of data transformation and guarantee that the target result satisfies the target structure and constraints. It allows users to view the other participants' information as an extension of its own information system, without concerning for heterogeneity.
- KonferenzbeitragBusiness rule verbalization(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Halpin, TerryBusiness rules should first be specified at the conceptual level, using concepts and languages easily understood by the business domain experts who are best qualified to validate the rules. This paper focuses on the verbalization of static business rules (i.e. constraints and derivation rules that apply to individual states of the business), ignoring dynamic rules relating to state transitions and/or workflows. We propose desirable language criteria for rule verbalization, and orthogonal dimensions by which rule verbalizations may be classified, and illustrate these general qualities with a wide variety of business rule examples, using model fragments depicted graphically in Entity-Relationship, Object-Role Modeling and Unified Modeling Language notations.
- KonferenzbeitragObject relational mapping techniques for .Net framework(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Doroshenko, Anatoliy; Romanenko, VladThe paper concerns the problem of building an object-relational mapping framework based on the Microsoft .Net platform. The work uses design patterns methodology and proposes to exploit powerful features of .Net as a managed objectoriented platform such as Common Type System, custom attributes and reflection. Such approach facilitates the development, can save efforts and serves as a solid ground for further improvements. An initial implementation of the framework has been developed and successfully used to build a business information system.
- KonferenzbeitragA novel multimedia data model supporting temporal semantic abstraction(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Yan, Jianfeng; Li, ZhanhuaiMost of researches on content descriptions and queries of temporal features only base on the thirteen kinds of temporal relationships defined by Allen, which are difficult to answer the queries of multimedia data that are built on temporal semantic abstraction. Based on the definition of Multimedia Object and Multimedia Data Unit (MDU), this paper focuses on the descriptive algorithm of generalization and aggregation, which are two kinds of important temporal semantic abstraction.
- KonferenzbeitragA conceptual modeling technique based on semantically complete model, its applications(Information systems technology and its applications, 3rd international conference ISTA'2004, 2004) Ovchinnikov, VladimirThe article proposes a conceptual modeling technique based on Semantically Complete model, the main property of which is that relations carry complete information about interconnection of underlying object types. The paper describes consequences of this property; the most important one is the possibility to use a model relation without its proper name. The author introduces Semantically Complete Query Language, expressions of which is formulated without relation names, describes a closure mechanism allowing to request an interconnection of indirectly related object types by means of a simple enumeration of them. The technique is applied to conceptual modeling of a metallurgical enterprise Manufacturing Execution System as an example. The article proposes use of Semantically Complete model as a unified data access interface to distributed data stored in systems of different architectures and placements, introduces a conception of Semantic Browser based on this interface. The browser permits to view and modify data, has an embedded mechanism of semantic navigation between points of view on information, and a mechanism of creation and publication of new view points by users.
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