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Database and Expert Systems Applications, 1997. Proceedings., Eighth International Workshop on

Date 1-2 Sept. 1997

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  • Database and Expert Systems Applications. 8th International Conference, DEXA '97. Proceedings

    Publication Year: 1997
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    Freely Available from IEEE
  • Specifying indefinite workflow-functions in ad-hoc dialogs

    Publication Year: 1997 , Page(s): 30 - 35
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    Within a workflow management system, a dialog system is suggested to handle indefinite (vague, imprecise) workflow situations. The Issue Based Information System (IBIS) may be extended by explanatory dialogs, allowing a debate on conclusions, premises and rules. Horizontal and vertical dimensions as well as productive and reductive directions are distinguished in an explanatory dialog in order to schematize and simplify workflow functions. View full abstract»

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  • Modeling samples processing in laboratory environments as scientific workflows

    Publication Year: 1997 , Page(s): 49 - 54
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    While workflow management appears to be an accepted technology in business applications and enterprises for enhancing their efficiency, its use in non business environments is still in its infancy. One such domain comprises scientific laboratories; the paper outlines how the workflow paradigm can fruitfully be employed in an environment of this kind. Specifically, it is indicated how to improve the management of processes and the processing of samples in laboratory environments. View full abstract»

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  • Cooperative and integrated workflow and document management for engineering applications

    Publication Year: 1997 , Page(s): 68 - 73
    Cited by:  Papers (2)
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    Engineering workflow management has to cope with a great variety of processes. Well structured and a priori defined activities are mixed with creative, less structured, and continuously evolving process steps. The classical coordination support provided by workflow management systems has to be enhanced to cope with dynamic, product centered, and cooperative processes. We concentrate on cooperation support within workflow management on both document level and workflow level. First, we propose an integrated and flexible approach to process and document management which is based on an object oriented modeling framework. We outline how different kinds of processes can be supported on this basis. Finally, we introduce an approach for flexible control and data flow modeling which supports cooperation on the workflow level and takes versioning and different forms of data interchange between activities into account. View full abstract»

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  • A search system based on image features

    Publication Year: 1997 , Page(s): 80 - 85
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    We present a system platform for the content based retrieval of images. The system has resulted in a prototype with two major steps: extraction and queries. We combine manual, semi automatic and automatic approaches in order to extract image regions (colors, shapes). Regions, which are extracted semi automatically, are significant and relevant for the final user. Shapes are represented by powerful mathematical formulas, so the representation of the shape is independent of the rotation, homothecie and translation. The features extracted are modeled, using object technology, in the database management system O2. The object modeling has several advantages such as simplification of the encapsulation of data that saves developers many details of particular image hardware or software. This makes the framework portable and extensible. View full abstract»

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  • Extending database space of INADA/ODMG for very large databases on 64 bit workstations

    Publication Year: 1997 , Page(s): 112 - 117
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    Discusses the properties of a 64-bit environment and the redesign of our 32-bit INADA/ODMG object management system for the 64-bit environment. The new implementation is introduced based on the 64-bit properties. In the new design, a very large on-disk database can be mapped onto a large-size virtual memory without considering the size limitation. High query performance and storage capability are expected in the new INADA/ODMG. While designing the implementation of a Sequoia 2000 benchmark, we came to the conclusion that OQL is flexible enough to handle massive amounts of complicated data. View full abstract»

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  • Designing navigational contexts using an OO query language

    Publication Year: 1997 , Page(s): 130 - 135
    Cited by:  Patents (4)
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    Discusses how to use an object-oriented (OO) query language for designing some features of hypermedia applications. We show that it allows designers to define navigational contexts by retrieving instances related by special relationships (one-to-many or aggregation relationships) specified in the conceptual model or as a set of a arbitrary instances where a condition holds. We first describe an OO hypermedia design model, supporting nodes, links and their anchors and perspectives. We then present the query language and give some examples showing our strategy to define navigational contexts. View full abstract»

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  • Towards a spatio-temporal OQL for the four dimensional spatial database system Hawks

    Publication Year: 1997 , Page(s): 142 - 147
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    Discusses a spatio-temporal object query language (OQL), which treats spatial data and temporal data in the same way. We address spatial, temporal and spatio-temporal predicates and operators, and then show the queries in the spatio-temporal OQL and the ones in the internal expression of the spatio-temporal database system Hawks. This language is going to be implemented in INADA/ODMG, which is a database programming language based on C++ and which provides the C++ bindings of the ODMG-93 Object Database Standard. The expressions, in which spatio-temporal objects are defined as the figures of the 4D topological space resulting from the direct product of the 3D space and time, are used to retrieve those spatio-temporal objects which satisfy a condition. View full abstract»

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  • Giving permission implies giving choice

    Publication Year: 1997 , Page(s): 198 - 203
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    When we want to examine different kinds of forms of acts within the framework of the description of the Dutch criminal law, whether an act is permitted or not permitted, we can encounter a difference. On the one hand, it could be the case that a certain act is permitted by a competent normative authority. On the other hand, it could be the case that in the Dutch criminal law a certain act is weak permitted without a competent normative authority having enacted that permission. The article presents the formalisation of the weak and strong permission in deontic logic based on the logic of enactment. A permission that follows from the absence of a prohibition, we call a weak permission; this permission is not enacted. A strong permission is always enacted (implicitly or explicitly), and implies a giving choice. The distinction between these two types of permission is a consequence of the universality of a normative system by the closure rule: 'whatever is not forbidden, is permitted'. View full abstract»

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  • An adaptive value-based scheduling policy for multiprocessor real-time database systems

    Publication Year: 1997 , Page(s): 254 - 259
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    In a real-time application, a transaction may be assigned a value to reflect the profit of completing the transaction before its deadline. Satisfying both goals of maximizing the totally obtained profit and minimizing the number of missed transactions at the same time is a challenge. The authors present an adaptive real-time scheduling policy named value-based processor allocation (VPA-k) for scheduling value-based transactions in a multiprocessor real-time database system. Using the VPA-k policy, the transactions with higher values are given higher priorities to execute first, while at most k percentage of total processors are dynamically allocated to execute the urgent transactions. Through simulation experiments, VPA-k is shown to outperform other scheduling policies substantially in both maximizing the totally obtained profit and minimizing the number of missed transactions under various system environments. View full abstract»

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  • Tree-based buffer management in real-time database systems

    Publication Year: 1997 , Page(s): 260 - 264
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    This paper deals with buffer management for tree-based access-path structures in real-time database system kernels. A predictable and efficient buffer replacement strategy for B- and B/sup +/-trees is introduced. The strategy called LC (Level Control) uses the structural information known about the trees and the tree search to determine a node to be replaced. The basic idea is to use the level of a node as replacement criteria. This allows a certain prediction of buffer hits and misses for tree search operations, even if the item's value searched for is unknown. A small prediction interval can be calculated for search operations and a larger interval for update operations. Simulations show the correctness of these calculations and the efficiency of LC for B- and B/sup +/-trees compared to common other replacement strategies. View full abstract»

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  • READS: a prototyping environment for real-time active applications

    Publication Year: 1997 , Page(s): 265 - 270
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    We present our Real-time Active Database System, READS, which is a prototyping environment for real-time active database applications on a conventional Unix environment, e.g., Solaris 2.4. In READS, transactions are associated with deadlines and priorities. Priority scheduling is supported by the real-time extensions provided in the underlying operating system. READS can be served as a testbed for evaluating different issues in the design of real-time active database systems (RTADBS). Different approaches for assigning deadlines and priorities to triggered transactions have been suggested and discussed. An application, the programmed trading database system, is implemented with READS and experiments have been performed to study the impact of the deadline constraints on the performance of the deferred and immediate coupling modes for triggering. View full abstract»

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  • ELEKTRA: an electronic article delivery service

    Publication Year: 1997 , Page(s): 272 - 277
    Cited by:  Patents (4)
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    With the success of the World-Wide Web new solutions for very fast document access have emerged. ELEKTRA is an article delivery system that supports full-text and relational information retrieval as well as electronic article ordering and delivery. Full-length articles can be both viewed by standard-web browsers and printed by PostScript printers in a high resolution quality. ELEKTRA has been realized by using the general multimedia digital library tool Omnis 4.0. View full abstract»

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  • Supporting adaptable technical information systems in heterogeneous environments-using WWW and ORDBMS

    Publication Year: 1997 , Page(s): 295 - 303
    Cited by:  Patents (8)
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    Due to the ever rising competition in nearly all industrial sectors, there is a strong need for integrated information systems (ISs) that will store, retrieve, manipulate and exchange information efficiently to support all activities in an enterprise. Moreover, such an IS should not be a one-size-fit-all or a permanent solution, rather, the adaptability must be pursued so that the system can deal with all possible changes resulting from new technologies or new application demands. We present our first experience with developing such an integrated IS for a technical application domain. From the data processing point of view, the environment to be managed consists of distributed client/server systems embodied by heterogeneous hardware and software components; unconventional data types such as multimedia data and HTML statements are to be managed, and effective and robust database (DB) support should be provided. To meet the challenges posed by these advanced applications, new information techniques, such as World Wide Web (WWW or Web) and object-relational database management systems (ORDBMSs), are employed to facilitate a platform-independent DB access via a versatile user interface, as well as powerful DB services with high extensibility. View full abstract»

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  • Design of a visual query language for hospital information systems

    Publication Year: 1997 , Page(s): 306 - 311
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    A visual query language, designed to be used in a hospital information system is presented. The language exhibits a high degree of adaptation to all kinds of users, as well as a powerful set of tools to formulate queries. It appears to be very simple to learn and it is especially suited to object oriented models. We have also developed a textual language equivalent to the visual one and we have made a comparison with relational algebra. View full abstract»

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  • Security concerns for mobile information systems in health care

    Publication Year: 1997 , Page(s): 312 - 317
    Cited by:  Patents (6)
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    We study the mutually restricting problems of permanent availability and legally demanded security of patient data in clinical information systems. Inefficiencies in today's clinical information management call for an integrated technological support for hospitals. In particular, client/server solutions offer the flexibility and spatial independence appreciated in health care. On the other hand, mobile client applications having access from nearly everywhere in a hospital to servers containing sensitive data arouse severe security problems. Additionally, the need for 24 hours per day and 7 days per week availability of patient data in hospital run information systems defines a conflicting border condition. We present a proposed approach developed in the Swiss National Science Foundation project MobiMed to support clinical processes technologically, including access control which is compatible with security mechanisms as well as everyday practical work consideration in clinical environments. View full abstract»

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  • Discovery and application of inter-class patterns in database

    Publication Year: 1997 , Page(s): 326 - 331
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    Presents an inter-class pattern discovery method for real-world databases. While the data in a conventional database has a tuple structure, the data in pattern discovery has set-values or sequences. The structural differences between them may cause useless resulting patterns, and may result in an inefficient pattern discovery method. To resolve those issues, we propose an inter-class pattern discovery methodology. The first step is to convert a conventional database into a set of objects. During the conversion process, a tuple in the original database is converted into a conceptual object and, as another result, object generalization hierarchies are generated. From the object generalization hierarchies, interesting patterns of the conceptual objects can be extracted by applying multi-level pattern discovery algorithms. The resulting patterns are inter-class patterns of the original conventional database. We also show a pattern discovery query for our methodology and its application to intelligent query processing. View full abstract»

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  • ATREUS: a model for the conceptual representation of a workflow

    Publication Year: 1997 , Page(s): 400 - 405
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    We propose a workflow conceptual model able to represent clinical and managerial activities within health-care structures, the ATREUS model. This model was defined taking into account the intrinsic difficulties and complexity of processes in the health-care domain. This model uses: hypergraphs to represent processes graphically; a textual representation which describes each activity; and a state diagram to control the activity development. The model allows a top-down refinement of processes. View full abstract»

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  • Towards flexible support for cooperation: group awareness in shared workspaces

    Publication Year: 1997 , Page(s): 406 - 411
    Cited by:  Papers (2)
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    In the last decade since computer-supported cooperative work (CSCW) constituted as a research area on its own many interesting findings about groups of cooperating individuals, cooperative work, and technical support thereof have been made and a huge variety of groupware applications have been built. However, there is a discrepancy between the theoretical concepts elaborated and the functionality of the groupware applications and shared workspace systems built. Actually most groupware systems and shared workspace systems support only highly specific tasks, situations and forms of group interaction. This paper argues for more flexible groupware applications and shared workspace systems, which adhere to those theoretical concepts, which are integrated smoothly through the provision of group awareness information, and which respect the interdependencies and interplay among them. View full abstract»

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  • Evaluating workflow management systems

    Publication Year: 1997 , Page(s): 412 - 417
    Cited by:  Papers (2)
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    We describe a project focusing on the evaluation of workflow management systems for a large Austrian bank. In the first part we establish a catalogue of evaluation criteria. It summarizes the huge amount of criteria into smaller classes (criteria categories) and orders the classes in a semantically structured directory. In the second part, we describe a tool implementing the evaluation framework. A database stores the criteria classes along with associated questions as well as the appropriate answers for a set of workflow products. The tool allows to extend the database as well as to perform a customized evaluation process. In the third part of the paper, we describe some of the results of using the tool for evaluating workflow management systems for the First Austrian Savings Bank. View full abstract»

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  • Web4Groups-a tool for telematic collaboration

    Publication Year: 1997 , Page(s): 425 - 430
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    This paper presents the web-based group communication service Web4Groups. First it is shown how the project to develop this service is organized. The work of the project consortium consisting of 12 European partners is described. It is further explained how specific user groups in different areas are involved and how their needs are integrated in the development process. Secondly, the Web4Groups service itself is described with respect to features and technical architecture. View full abstract»

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  • Extending the Van der Veer approach to cooperative work: a bridge between groupware task analysis and workflow design

    Publication Year: 1997 , Page(s): 431 - 439
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    Recent evolution in IT research have brought different design methods for CSCW systems. Efforts to meet the requirements of integral solutions for CSCW systems are shifting: WFMS put the focus on support and automation of design/execution of tasks, database- and document management, status monitoring, etc. Most improvements comply with a bottom-up approach. The Groupware approach starts with a holistic view of work and so is top-down directed. In breaking down work to tasks GTA plays a major role. GTA is a promising approach to improvement of conventional task analysis because it achieves significant progress by including group cooperation. Yet, GTA suffers from neglecting conventional organisational structures and technical information infrastructure already in use. This paper introduces the Extended GTA, a design approach which bridges the gaps between Workflow Analysis and GTA. EGTA uses GTA as base and considers users, work practices, work organisations, information infrastructure, and interdependencies between the domains. View full abstract»

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  • Applying evolutionary algorithms to the problem of information filtering

    Publication Year: 1997 , Page(s): 450 - 458
    Cited by:  Papers (2)  |  Patents (13)
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    This paper presents an intelligent information filtering system that learns from user feedback and behavior through evolutionary algorithms. By applying the learning abilities of a classifier system and genetic algorithms to the system, the following tasks can be performed: (1) reducing a user's information overload; (2) predicting the actions that the users are supposed to do; and (3) prioritizing electronic mail. View full abstract»

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  • One application of neural networks for detection of defects using video data bases: identification of road distresses

    Publication Year: 1997 , Page(s): 459 - 464
    Cited by:  Papers (4)
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    Describes an application of neural networks to the discovery of road surface distresses (cracks, etc.) from video sequences. After describing the context of this application, we detail its progressive design. We initially thought of using only one neural network to totally analyze each image extracted from a video sequence. We later thought of a more simple neural network analyzing only a small part of each image each time, with a preprocessor scanning the image. We finally preferred to simplify the role of the neural network by putting an image preprocessing sequence in front, to extract objects that were then identified by the neural network. We describe the sequence of treatments that we use and detail each processing step: improvement of the original image, extraction of significant objects (possible distresses) and identification of these objects by the neural network. We conclude by evaluating the performance of our system and by discussing possible improvements. View full abstract»

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  • Semantic cooperation of legacy information systems: an object-oriented framework

    Publication Year: 1997 , Page(s): 488 - 493
    Cited by:  Papers (1)
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    When several legacy information systems have to cooperate, the issue is to define a global framework providing both semantic interoperability and loose coupling among heterogeneous local information sources. To conciliate such requirements, we propose an object-oriented framework dedicated to the semantic evaluation of global queries while respecting local autonomy. Several layers insure interoperability through application objects and actual cooperation at a meta-level composed of federative objects. A unified description of local data allows structural and semantic evaluations during query processing. To preserve local autonomy, the description is dynamically derived from local data structures. Federative objects exploit a cooperation protocol to coordinate the exchanges during query evaluation. View full abstract»

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