5,572 research outputs found

    Introducing Dynamic Behavior in Amalgamated Knowledge Bases

    Full text link
    The problem of integrating knowledge from multiple and heterogeneous sources is a fundamental issue in current information systems. In order to cope with this problem, the concept of mediator has been introduced as a software component providing intermediate services, linking data resources and application programs, and making transparent the heterogeneity of the underlying systems. In designing a mediator architecture, we believe that an important aspect is the definition of a formal framework by which one is able to model integration according to a declarative style. To this purpose, the use of a logical approach seems very promising. Another important aspect is the ability to model both static integration aspects, concerning query execution, and dynamic ones, concerning data updates and their propagation among the various data sources. Unfortunately, as far as we know, no formal proposals for logically modeling mediator architectures both from a static and dynamic point of view have already been developed. In this paper, we extend the framework for amalgamated knowledge bases, presented by Subrahmanian, to deal with dynamic aspects. The language we propose is based on the Active U-Datalog language, and extends it with annotated logic and amalgamation concepts. We model the sources of information and the mediator (also called supervisor) as Active U-Datalog deductive databases, thus modeling queries, transactions, and active rules, interpreted according to the PARK semantics. By using active rules, the system can efficiently perform update propagation among different databases. The result is a logical environment, integrating active and deductive rules, to perform queries and update propagation in an heterogeneous mediated framework.Comment: Other Keywords: Deductive databases; Heterogeneous databases; Active rules; Update

    A conditional role-involved purpose-based access control model

    Get PDF
    This paper presents a role-involved conditional purpose-based access control (RCPBAC) model, where a purpose is defined as the intension of data accesses or usages. RCPBAC allows users using some data for certain purpose with conditions. The structure of RCPBAC model is defined and investigated. An algorithm is developed to achieve the compliance computation between access purposes (related to data access) and intended purposes (related to data objects) and is illustrated with role-based access control (RBAC) to support RCPBAC. According to this model, more information from data providers can be extracted while at the same time assuring privacy that maximizes the usability of consumers' data. It extends traditional access control models to a further coverage of privacy preserving in data mining environment as RBAC is one of the most popular approach towards access control to achieve database security and available in database management systems. The structure helps enterprises to circulate clear privacy promise, to collect and manage user preferences and consent

    Extended RBAC with role attributes

    Get PDF
    Though RBAC has been researched for many years as a current dominant access control technology, there are few researches to be done to address the further extension of the role which is the fundamental entity of RBAC. This paper tries to extend the role to a further level, the role attributes. Through the attributes, the function and operation on the role can be enhanced and extended. Through the attributes, ANSI RBAC is significantly extended. In the inheritance of hierarchical role, the privacy of its parental role can be kept by using HA (Hidden Attribute)

    On the Selection of Optimal Index Configuration in OO Databases

    Get PDF
    An operation in object-oriented databases gives rise to the processing of a path. Several database operations may result into the same path. The authors address the problem of optimal index configuration for a single path. As it is shown an optimal index configuration for a path can be achieved by splitting the path into subpaths and by indexing each subpath with the optimal index organization. The authors present an algorithm which is able to select an optimal index configuration for a given path. The authors consider a limited number of existing indexing techniques (simple index, inherited index, nested inherited index, multi-index, and multi-inherited index) but the principles of the algorithm remain the same adding more indexing technique

    Hierarchical Role-Based Access Control with Homomorphic Encryption for Database as a Service

    Full text link
    Database as a service provides services for accessing and managing customers data which provides ease of access, and the cost is less for these services. There is a possibility that the DBaaS service provider may not be trusted, and data may be stored on untrusted server. The access control mechanism can restrict users from unauthorized access, but in cloud environment access control policies are more flexible. However, an attacker can gather sensitive information for a malicious purpose by abusing the privileges as another user and so database security is compromised. The other problems associated with the DBaaS are to manage role hierarchy and secure session management for query transaction in the database. In this paper, a role-based access control for the multitenant database with role hierarchy is proposed. The query is granted with least access privileges, and a session key is used for session management. The proposed work protects data from privilege escalation and SQL injection. It uses the partial homomorphic encryption (Paillier Encryption) for the encrypting the sensitive data. If a query is to perform any operation on sensitive data, then extra permissions are required for accessing sensitive data. Data confidentiality and integrity are achieved using the role-based access control with partial homomorphic encryption.Comment: 11 Pages,4 figures, Proceedings of International Conference on ICT for Sustainable Developmen

    Effect of matrix parameters on mesoporous matrix based quantum computation

    Full text link
    We present a solid state implementation of quantum computation, which improves previously proposed optically driven schemes. Our proposal is based on vertical arrays of quantum dots embedded in a mesoporous material which can be fabricated with present technology. We study the feasibility of performing quantum computation with different mesoporous matrices. We analyse which matrix materials ensure that each individual stack of quantum dots can be considered isolated from the rest of the ensemble-a key requirement of our scheme. This requirement is satisfied for all matrix materials for feasible structure parameters and GaN/AlN based quantum dots. We also show that one dimensional ensembles substantially improve performances, even of CdSe/CdS based quantum dots

    Key Components for an Ethics Consultation Curriculum

    Get PDF
    Due to a lack of formal credentials for clinical ethics consultants, the professionalization of clinical ethics as a normative discipline in contemporary American health care is diminished amongst other health care professionals. While medical specialties, organizational leadership positions, and other miscellaneous health care occupations possess governing bodies that posit credentials that justify these roles, clinical ethics consultants lack a standard of competence. While this gap has been temporarily reconciled by individual employer criteria, a national standard that attempts to educate and demonstrate a clinical ethicist’s abilities does not exist. Still, various attempts have been made to establish a certification program for clinical ethicists. These programs contain central concepts in ethics consultation and are effective in demonstrating the impact of a clinical ethicist’s knowledge. However, the educational facets entailed in proposed certification programs that clinical ethicist ought to be familiar with do not include information surrounding the nature of clinical ethics and the role a clinical ethicist must embody in order to perform his job effectively. The central supposition of this dissertation is that additional work needs to be completed around clinical ethics education and certification. While no formal certification or educational standard exists for clinical ethicists, this dissertation proposes key components for an ethics consultation curriculum. The key components in this dissertation emphasize the nature and value of virtue in clinical ethics and the role virtue plays in orchestrating an effective certification program for ethicists. This dissertation aims to do the following: (i) Clarify and demonstrate the problems associated with a lack of formal certification standard for ethicists; (ii) Define and examine the nature of clinical ethics and the role philosophy plays in this line of work; (iii) Explain and demonstrate the effectiveness of teaching virtues as key components for a formalized ethics consultation curriculum; and (iv) Illustrate how key components for an ethics consultation curriculum manifest in an educational venue for clinical ethicists. This dissertation seeks to contribute a novel approach to educating and certifying clinical ethicists in the United States. By combining knowledge points associated with moral philosophy and medicine with general skill objectives for ethics consultants, this dissertation aids in developing analytic moral reasoning skills for clinical ethicists which in turn fosters the overall education and professional development of clinical ethics consultants
    corecore