36 research outputs found

    Efficient Database-Driven Evaluation of Security Clearance for Federated Access Control of Dynamic XML Documents

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    Abstract. Achieving data security over cooperating web services is becoming a reality, but existing XML access control architectures do not consider this federated service computing. In this paper, we consider a federated access control model, in which Data Provider and Policy Enforcers are separated into different organizations; the Data Provider is responsible for evaluating criticality of requested XML documents based on co-occurrence of security objects, and issuing security clearances. The Policy Enforcers enforce access control rules reflecting their organization-specific policies. A user’s query is sent to the Data Provider and she needs to obtain a permission from the Policy Enforcer in her organization to read the results of her query. The Data Provider evaluates the query and also evaluate criticality of the query, where evaluation of sensitiveness is carried out by using clearance rules. In this setting, we present a novel approach, called the DIFF approach, to evaluate security clearance by the Data Provider. Our technique is build on top of relational framework and utilizes pre-evaluated clearances by taking the differences (or deltas) between query results.

    Program Slicing on VHDL Descriptions and Its Applications

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    We propose applying program slicing to hardware description language VHDL; program slicing is a technique developed in the software engineering field, and it can extract all the sentences which have a certain dependence to a given sentence, and it can be utilized for analysis and modification of programs. Program slicing for hardware description languages should have a variety of applications in VLSI CAD, such as functional verification, test generation, designer assistance, and design synthesis. We show several examples of program slicing on VHDL descriptions, and address a list of related issues. 1 Introduction Hardware description languages (HDLs) are now being widely used as a tool for total system description, from low-level circuit descriptions to high-level abstract and conceptual descriptions. As design resources in the form of HDL descriptions are going to be accumulated, verification, maintenance and reuse of HDL descriptions will become an important issue. We propose apply..

    Private-iye: A framework for privacy preserving data integration

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    Data integration has been a long standing challenge to the database and data mining communities. This need has become critical in numerous contexts, including building e-commerce market places, sharing data from scientific research, and improving homeland security. However, these important activities are hampered by legitimate and widespread concerns of data privacy. It is necessary to develop solutions that enable integration of data, especially in the domains of national priorities, while effective privacy control of the data. In this paper, we present an architecture and key research issues for building such a privacy preserving data integration system called PRIVATE-IYE.

    A System for Querying and Viewing Business Constraints

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    In E-commerce processes, various rules and constraints regarding product specifications, pricing, terms and conditions are exchanged between vendors and buyers. Developing a formal model for those rules and constraints gives a foundation for new E-commerce applications. Our approach is to develop a constraint database holding these conditions as dynamic constraints and provide a query language, called dynamic constraint algebra (DCA), for retrieving and matching business constraints

    Polymorphic Crystallization and Thermodynamic Phase Transition between the Polymorphs of a Photochromic Diarylethene

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    We synthesized a photochromic diarylethene, 1,2-bis­(2-methyl-5-(4-hexyloxyphenyl)-3-thienyl)­perfluorocyclopentene (<b>1a</b>), and found that it has two types of crystals, a needle-like α-crystal and a plate-like β-crystal. From X-ray crystallographic analysis, the space groups of the α- and β-crystals were determined to be <i>P</i>1̅ and <i>C</i>2/<i>c</i>, respectively. The molecular conformation and packing of two crystal forms are quite different. The α- and β-crystals can be obtained individually by recrystallization from acetone at different temperatures. The solvent-mediated phase transition from the α-crystal to the β-crystal was found to occur in the acetone solution at room temperature. Moreover, the thermodynamic phase transition from α-form to β-form was found to take place above 88 °C, as confirmed by differential scanning calorimetry measurement, optical microscopic observation under crossed Nicols, and powder X-ray diffraction measurement. The phase transition from α-form to β-form was also observed at 78 °C by photochromic reaction of <b>1a</b>, and the phase transition proceeded from the UV irradiated part to the nonirradiated part
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