Search results for "InformationSystems_DATABASEMANAGEMENT"
showing 10 items of 50 documents
RDB2OWL
2010
RDB2OWL is a simple approach of mapping relational databases into independently developed OWL ontologies. The approach is based on creating a mapping RDB schema, filling it with mapping information from which SQL scripts are generated that perform the instance-level transformation. We describe the RDB2OWL mapping schema and report on successful application of the technology to the migration of Latvian medical registries data.
The Effects of Database Complexity on SQL Query Formulation
2020
In Structured Query Language (SQL) education, students often execute queries against a simple exercise database. Recently, databases that are more realistic have been utilized to the effect that students find exercises more interesting and useful, as these databases more accurately mimic databases students are likely to encounter in their future work environments. However, using even the most engaging database can be counterproductive to learning, if a student is not able to formulate correct queries due to the complexity of the database schema. Scientific evidence on the effects of database complexity on student’s query formulation is limited, and with queries from 744 students against thr…
ViziQuer: A Web-Based Tool for Visual Diagrammatic Queries Over RDF Data
2018
We demonstrate the open source ViziQuer tool for web-based creation and execution of visual diagrammatic queries over RDF/SPARQL data. The tool supports the data instance level and statistics queries, providing visual counterparts for most of SPARQL 1.1 select query constructs, including aggregation and subqueries. A query environment can be created over a user-supplied SPARQL endpoint with known data schema (a data schema exploration service is available, as well). There are pre-defined demonstration query environments for a mini-university data set, a fragment of synthetic similar to reality hospital data set, and a variant of Linked Movie Database RDF data set.
Datamining: Pemanfaatan Algoritma Apriori dalam Menganalisa Pola-Pola Transaksi yang Terjadi
2012
This paper will be described about implementation and analysis of the well-known apriori algorithm, which is called Market Basket Analysis (MBA) in data mining. This algorithm is widely used to predict the relation among market basket in the huge amount of database. This algorithm is based on the concept of a prefix tree. There are several ways to organize the nodes of such a tree, to encode the items, and to organize the transactions, which may be used in order to minimize the time needed to find the frequent itemsets as well as to reduce the amount of memory needed to store the counters. The rules produced will be used by management of supermarket to organize the items set to increase the…
Optimisation des requêtes de similarité dans les espaces métriques répondant aux besoins des usagers
2012
The complexity of data stored in large databases has increased at very fast paces. Hence, operations more elaborated than traditional queries are essential in order to extract all required information from the database. Therefore, the interest of the database community in similarity search has increased significantly. Two of the well-known types of similarity search are the Range (Rq) and the k-Nearest Neighbor (kNNq) queries, which, as any of the traditional ones, can be sped up by indexing structures of the Database Management System (DBMS). Another way of speeding up queries is to perform query optimization. In this process, metrics about data are collected and employed to adjust the par…
Design-based estimation for geometric quantiles with application to outlier detection
2010
Geometric quantiles are investigated using data collected from a complex survey. Geometric quantiles are an extension of univariate quantiles in a multivariate set-up that uses the geometry of multivariate data clouds. A very important application of geometric quantiles is the detection of outliers in multivariate data by means of quantile contours. A design-based estimator of geometric quantiles is constructed and used to compute quantile contours in order to detect outliers in both multivariate data and survey sampling set-ups. An algorithm for computing geometric quantile estimates is also developed. Under broad assumptions, the asymptotic variance of the quantile estimator is derived an…
Efficient evaluation for a subset of recursive queries
1991
Abstract We consider the efficient evaluation of recursive queries in logic databases where the queries are expressed using a Datalog program (function-free Horn-clause program) that contains only regularly or linearly recursive predicates. Using well-known results on graph traversal, we develop an efficient algorithm for evaluating relations defined by a binary-chain program. We also present a transformation by which the evaluation of a subset of queries involving nonbinary relations can be reduced to the evaluation of binary-chain queries. This transformation is guided by the choice of bound arguments in the query, and the bindings are propagated through the program so that in the evaluat…
Indexing Method for Transitive Relationships of Product Information
2008
To successfully use a relational database management system (RDBMS) as a repository for product information, the RDBMS must efficiently process and properly answer ontological queries. The key to processing the ontological queries is whether the various semantic relationships among the concepts of the product ontology are likewise well-processed. In particular, the transitive relationships (e.g., is-a, component-of relationships) such as ancestors-descendents, parents-children, and taxonomy of products must be processed successfully. We propose an efficient index using a numbering scheme (labeling scheme) to process queries over transitive relationships. (This paper is an extended version o…
The social and environmental impacts of mining activitieson indigenious communities : the case of Newmont Gold (Gh) limited (Kenyasi) in Ghana
2010
Masteroppgave i development management- Universitetet i Agder 2010 The study explores and assesses mining and its impacts on communities within which mining activities takes place. The focus has been on a mining community in Ghana called Kenyasi where mining is vigorously carried out by an American mining giant, Newmont Mining Corporation. The study investigates the real and latent impacts of mining activities on the community in the light of the numerous promises and prospects that mining is said to provide for communities. Mining for many decades served as an important component of countries‟ revenue source especially for developing countries that have been endowed with the mineral wealth…
Research Directions of OLAP Personalizaton
2011
In this paper we have highlighted five existing approaches for introducing personalization in OLAP: preference constructors, dynamic personalization, visual OLAP, recommendations with user session analysis and recommendations with user profile analysis and have analyzed research papers within these directions. We have provided an evaluation in order to point out (i) personalization options, described in these approaches, and its applicability to OLAP schema elements, aggregate functions, OLAP operations, (ii) the type of constraints (hard, soft or other), used in each approach, (iii) the methods for obtaining user preferences and collecting user information. The goal of our paper is to syst…