Spelling suggestions: "subject:"database"" "subject:"catabase""
471 |
Multipaged implementation of MRDS on UNIXPal, Jatinder. January 1984 (has links)
No description available.
|
472 |
Alignment of competencies as identified by library and information science educators and practitioners : a case study of database managementNwakanma, Chukwuemeka Dean January 2008 (has links)
Library and Information Science (LIS) education must equip its graduates with the level of competence commensurate with the demands of entry-level positions available in the field. This is more so in the area of information technology (IT) that is widely acknowledged to be rapidly evolving thereby offering unique job specifications and or positions in LIS. This exploratory research investigates the extent of alignment between the level of competence proposed in learning objectives by LIS educators, and the level of competence required from LIS graduates by practitioners in the field. The study focuses specifically on cognitive competence, and in the domain of database management (DBM) within LIS education in US and Canada. The Taxonomy Table (TT) designed by Anderson and Krathwohl (2001) was used as a conceptual framework, to analyze learning objectives obtained from DBM educators and practitioners to determine the levels of competence proposed by educator and practitioners in DBM. The levels of competence derived from educators and practitioners were then compared to determine the extent of alignment between the levels of competence offered by LIS educators, and the levels of competence expectations of LIS practitioners from graduates in DBM. / Une fonnation en bibliothéconomie et les sciences de l’infonnation (BSI) doit équiper ses finissants de compétences qui répondent aux besoins du marché du travail. C’est d’autant plus vrai dans le domaine des technologies de l’infonnation et des communications où il est reconnue y avoir une évolution rapide créant des caractéristiques de tâches et/ou des emplois uniques en BSI. Cette recherche exploratoire examine le degré de concordance entre le niveau de compétences proposé par les objectifs d’apprentissages émis par les éducateurs en BSI et celui demandé aux finissants en BSI par les professionnels du domaines. L’étude est concentrée spécifiquement sur les compétences cognitives dans le domaine de la gestion de bases de données (GBD) dans les contexte d’une éducation en BSI aux États-Unis et au Canada. Le tableau taxonomique conçut par Anderson et Krathwohl (2001) sert de cadre conceptuel pennettant d’analyser les objectifs d’apprentissage obtenus chez les éducateurs et les professionnels. Cette analyse détennine le niveau de compétence offert par les éducateurs et celui demandé par les professionnels. Ces niveaux sont ensuite comparés afin de quantifier le degré de concordance entre les niveaux de compétence offerts par les éducateurs en BSI et les attentes que les finissants en BSI devront combler afin de satisfaire les professionnels en BSI en se qui attrait à la GBD.
|
473 |
Aggregation and Privacy in Multi-Relational DatabasesJafer, Yasser 11 April 2012 (has links)
Most existing data mining approaches perform data mining tasks on a single data table. However, increasingly, data repositories such as financial data and medical records, amongst others, are stored in relational databases. The inability of applying traditional data mining techniques directly on such relational database thus poses a serious challenge. To address this issue, a number of researchers convert a relational database into one or more flat files and then apply traditional data mining algorithms. The above-mentioned process of transforming a relational database into one or more flat files usually involves aggregation. Aggregation functions such as maximum, minimum, average, standard deviation, count and sum are commonly used in such a flattening process.
Our research aims to address the following question: Is there a link between aggregation and possible privacy violations during relational database mining? In this research we investigate how, and if, applying aggregation functions will affect the privacy of a relational database, during supervised learning, or classification, where the target concept is known. To this end, we introduce the PBIRD (Privacy Breach Investigation in Relational Databases) methodology. The PBIRD methodology combines multi-view learning with feature selection, to discover the potentially dangerous sets of features as hidden within a database. Our approach creates a number of views, which consist of subsets of the data, with and without aggregation. Then, by identifying and investigating the set of selected features in each view, potential privacy breaches are detected. In this way, our PBIRD algorithm is able to discover those features that are correlated with the classification target that may also lead to revealing of sensitive information in the database.
Our experimental results show that aggregation functions do, indeed, change the correlation between attributes and the classification target. We show that with aggregation, we obtain a set of features which can be accurately linked to the classification target and used to predict (with high accuracy) the confidential information. On the other hand, the results show that, without aggregation we obtain another different set of potentially harmful features. By identifying the complete set of potentially dangerous attributes, the PBIRD methodology provides a solution where the database designers/owners can be warned, to subsequently perform necessary adjustments to protect the privacy of the relational database.
In our research, we also perform a comparative study to investigate the impact of aggregation on the classification accuracy and on the time required to build the models. Our results suggest that in the case where a database consists only of categorical data, aggregation should especially be used with caution. This is due to the fact that aggregation causes a decrease in overall accuracies of the resulting models. When the database contains mixed attributes, the results show that the accuracies without aggregation and with aggregation are comparable. However, even in such scenarios, schemas without aggregation tend to slightly outperform. With regard to the impact of aggregation on the model building time, the results show that, in general, the models constructed with aggregation require shorter building time. However, when the database is small and consists of nominal attributes with high cardinality, aggregation causes a slower model building time.
|
474 |
Algorithms and data structures for the implimentation of a relational database systemOrenstein, J. A. January 1982 (has links)
The problems of implementing a relational database are considered. In part 1, a new class of data structures for processing range queries is described. A member of this class is derived from a data structure which supports random and sequential accessing. We also describe two new data structures with this property that seem to have better performance than the Btree. In part 2, a new design for the physical database is proposed. This design is based on the separation of a relation into two parts: a static "master file" and a dynamic "differential file" which stores updates. Our design includes a new system for recovering from system failures and allows greater concurrency than is possible with existing systems.
|
475 |
Document management and retrieval for specialised domains: an evolutionary user-based approachKim, Mihye, Computer Science & Engineering, Faculty of Engineering, UNSW January 2003 (has links)
Browsing marked-up documents by traversing hyperlinks has become probably the most important means by which documents are accessed, both via the World Wide Web (WWW) and organisational Intranets. However, there is a pressing demand for document management and retrieval systems to deal appropriately with the massive number of documents available. There are two classes of solution: general search engines, whether for the WWW or an Intranet, which make little use of specific domain knowledge or hand-crafted specialised systems which are costly to build and maintain. The aim of this thesis was to develop a document management and retrieval system suitable for small communities as well as individuals in specialised domains on the Web. The aim was to allow users to easily create and maintain their own organisation of documents while ensuring continual improvement in the retrieval performance of the system as it evolves. The system developed is based on the free annotation of documents by users and is browsed using the concept lattice of Formal Concept Analysis (FCA). A number of annotation support tools were developed to aid the annotation process so that a suitable system evolved. Experiments were conducted in using the system to assist in finding staff and student home pages at the School of Computer Science and Engineering, University of New South Wales. Results indicated that the annotation tools provided a good level of assistance so that documents were easily organised and a lattice-based browsing structure that evolves in an ad hoc fashion provided good efficiency in retrieval performance. An interesting result suggested that although an established external taxonomy can be useful in proposing annotation terms, users appear to be very selective in their use of terms proposed. Results also supported the hypothesis that the concept lattice of FCA helped take users beyond a narrow search to find other useful documents. In general, lattice-based browsing was considered as a more helpful method than Boolean queries or hierarchical browsing for searching a specialised domain. We conclude that the concept lattice of Formal Concept Analysis, supported by annotation techniques is a useful way of supporting the flexible open management of documents required by individuals, small communities and in specialised domains. It seems likely that this approach can be readily integrated with other developments such as further improvements in search engines and the use of semantically marked-up documents, and provide a unique advantage in supporting autonomous management of documents by individuals and groups - in a way that is closely aligned with the autonomy of the WWW.
|
476 |
Maintaining Global Consistency in Advanced Database SystemsJohn Gilmore Unknown Date (has links)
The thesis examines issues of consistency maintenance in advanced database systems; primarily, multidatabase systems. A multidatabase system consists of a number of pre-existing local database systems. A local database system is unaware of its participation in the multidatabase system and, likewise, the multidatabase system has no knowledge of local transaction executions. Enforcing global constraints in such an environment is clearly a challenging task. A methodology for constraint enforcement is presented which utilises existing technology for the replication of data in an attempt to enforce global consistency. While it is shown to have limited applicability, it is nonetheless an interesting study and serves to qualify the limits of such a solution. An alternative method for global consistency maintenance, which relies on the existence of triggers at each of the participant local databases, is then discussed. This method is shown to be particularly suitable when the issue of local database autonomy is of concern. It is, however, only suited to systems where each of the local databases provides a capability for triggering external actions based on the occurrence of particular database events. As a result of this methodology, the requirement for identification of enforcement actions which access sites where the instigating transaction originated becomes apparent. Such enforcement actions can cause deadlock in certain circumstances when they are executed at the same site which initially triggered the global constraint. This issue is dealt with in a novel way by proposing a methodology for statically checking relations at each participant site with a view to determining their susceptibility to this form of deadlock. The method, a graphical representation of the constraint enforcement process in a distributed system, is also shown to have other desirable properties. Arising from the requirements of other work within the thesis, an algorithm for detecting all cycles in a given directed graph is presented. It is shown that, while the well-known adaptation of the Depth First Search algorithm to cycle detection in directed graphs can detect the existence of cycles, it cannot in all circumstances identify all cycles. An algorithm which performs this task is presented together with an analysis of its complexity and correctness. In a more general sense, the issue of deferred constraint enforcement is discussed. Several scenarios where deferred enforcement of constraints is required are presented, together with a method for detecting the presence of cyclic dependencies within a given database schema.
|
477 |
Spatial cadastral information systems: the maintenance of digital cadastral mapsEffenberg, Wolfgang Unknown Date (has links) (PDF)
The management of a cadastral system's digital spatial data has promptedconsiderable research, generally with a focus limited to the organisationmaintaining the cadastral map. The approach of viewing the maintenanceof cadastral maps as a system encompassing the entire cadastral industryhas not been comprehensively studied and documented. This approach isseen as essential to transform cadastral mapping from its currentorganisation specific isolation, into a form that is truly interoperable withthe processing of spatial cadastral information in a digital environment.This dissertation documents a research program that is essentially adefinition and an analysis and design of spatial cadastral systems withparticular emphasis on the Australian State of Victoria. The researchsubstantiates the existence of a spatial cadastral system within the overallcadastral system. A review is presented of the analysis of a number ofinternational, western spatial cadastral systems, and establishes theboundary of the spatial cadastral system. An investigation of systemmethodologies used in cadastral research and information systemsconcludes the applicability of the Zachman Framework to structure anddocument the more comprehensive analysis of spatial cadastral systems.This analysis is undertaken for the spatial cadastral systems of theAustralian State of Victoria.The impacting developments, such as enabling technology, coupled withuser requirements and issues relating to existing spatial cadastralsystems, provides the basis for the presentation of a range of solutionalternatives to manage the spatial data associated with the maintenanceof the multipurpose cadastral map in a digital and Internet enabledenvironment.
|
478 |
A metadata management system for web based SDIsPhillips, Andrew Heath Unknown Date (has links)
The process of decision making is best undertaken with the consideration of as much information as possible. One way to maximise the amount of information that is being used in the process is to use metadata engines. Metadata engines can be used to create virtual databases which are a collection of individual datasets located over a network. Virtual databases allow decisions to be made using data from many different data bases at many different locations on a network. They shield the user from this fact. From the users point of view they are only using data from the one location. This thesis investigates some of the concepts behind metadata engines for Internet based Spatial Data Infrastructures. The thesis has a particular emphasis on how metadata engines can be used to create virtual databases that could be of use in the planning and decision making processes. The thesis also investigates some current spatial data technologies such as SDIs, data warehouses, data marts and clearing houses, their interoperability and their relationship to metadata engines. It also explores some of the more recent spatial data applications that have been developed in the context of metadata engines and Spatial Data Infrastructures.
|
479 |
Document management and retrieval for specialised domains: an evolutionary user-based approachKim, Mihye, Computer Science & Engineering, Faculty of Engineering, UNSW January 2003 (has links)
Browsing marked-up documents by traversing hyperlinks has become probably the most important means by which documents are accessed, both via the World Wide Web (WWW) and organisational Intranets. However, there is a pressing demand for document management and retrieval systems to deal appropriately with the massive number of documents available. There are two classes of solution: general search engines, whether for the WWW or an Intranet, which make little use of specific domain knowledge or hand-crafted specialised systems which are costly to build and maintain. The aim of this thesis was to develop a document management and retrieval system suitable for small communities as well as individuals in specialised domains on the Web. The aim was to allow users to easily create and maintain their own organisation of documents while ensuring continual improvement in the retrieval performance of the system as it evolves. The system developed is based on the free annotation of documents by users and is browsed using the concept lattice of Formal Concept Analysis (FCA). A number of annotation support tools were developed to aid the annotation process so that a suitable system evolved. Experiments were conducted in using the system to assist in finding staff and student home pages at the School of Computer Science and Engineering, University of New South Wales. Results indicated that the annotation tools provided a good level of assistance so that documents were easily organised and a lattice-based browsing structure that evolves in an ad hoc fashion provided good efficiency in retrieval performance. An interesting result suggested that although an established external taxonomy can be useful in proposing annotation terms, users appear to be very selective in their use of terms proposed. Results also supported the hypothesis that the concept lattice of FCA helped take users beyond a narrow search to find other useful documents. In general, lattice-based browsing was considered as a more helpful method than Boolean queries or hierarchical browsing for searching a specialised domain. We conclude that the concept lattice of Formal Concept Analysis, supported by annotation techniques is a useful way of supporting the flexible open management of documents required by individuals, small communities and in specialised domains. It seems likely that this approach can be readily integrated with other developments such as further improvements in search engines and the use of semantically marked-up documents, and provide a unique advantage in supporting autonomous management of documents by individuals and groups - in a way that is closely aligned with the autonomy of the WWW.
|
480 |
Document management and retrieval for specialised domains: an evolutionary user-based approachKim, Mihye, Computer Science & Engineering, Faculty of Engineering, UNSW January 2003 (has links)
Browsing marked-up documents by traversing hyperlinks has become probably the most important means by which documents are accessed, both via the World Wide Web (WWW) and organisational Intranets. However, there is a pressing demand for document management and retrieval systems to deal appropriately with the massive number of documents available. There are two classes of solution: general search engines, whether for the WWW or an Intranet, which make little use of specific domain knowledge or hand-crafted specialised systems which are costly to build and maintain. The aim of this thesis was to develop a document management and retrieval system suitable for small communities as well as individuals in specialised domains on the Web. The aim was to allow users to easily create and maintain their own organisation of documents while ensuring continual improvement in the retrieval performance of the system as it evolves. The system developed is based on the free annotation of documents by users and is browsed using the concept lattice of Formal Concept Analysis (FCA). A number of annotation support tools were developed to aid the annotation process so that a suitable system evolved. Experiments were conducted in using the system to assist in finding staff and student home pages at the School of Computer Science and Engineering, University of New South Wales. Results indicated that the annotation tools provided a good level of assistance so that documents were easily organised and a lattice-based browsing structure that evolves in an ad hoc fashion provided good efficiency in retrieval performance. An interesting result suggested that although an established external taxonomy can be useful in proposing annotation terms, users appear to be very selective in their use of terms proposed. Results also supported the hypothesis that the concept lattice of FCA helped take users beyond a narrow search to find other useful documents. In general, lattice-based browsing was considered as a more helpful method than Boolean queries or hierarchical browsing for searching a specialised domain. We conclude that the concept lattice of Formal Concept Analysis, supported by annotation techniques is a useful way of supporting the flexible open management of documents required by individuals, small communities and in specialised domains. It seems likely that this approach can be readily integrated with other developments such as further improvements in search engines and the use of semantically marked-up documents, and provide a unique advantage in supporting autonomous management of documents by individuals and groups - in a way that is closely aligned with the autonomy of the WWW.
|
Page generated in 0.0366 seconds