Basic Query Research Articles

Linearization and Completeness Results for Terminating Transitive Closure Queries on Spatial Databases

We study queries to spatial databases, where spatial data are modeled as semi-algebraic sets, using the relational calculus with polynomial inequalities as a basic query language. We work with the extension of the relational calculus with terminating transitive closures. The main result is that this language can express the linearization of semialgebraic databases. We also show that the sublanguage with linear inequalities only can express all computable queries on semilinear databases. As a consequence of these results, we obtain a completeness result for topological queries on semialgebraic databases.

메타데이터 정보를 이용한 분산 KRISTAL-2002 시스템의 통합 검색 시스템 개발

본 논문에서는 메타데이터fmf 이용하여 분산된 KRISTAL-2002 기반의 시스템을 통합 검색하는 정보검색시스템의 구현 방법을 제안한다. 이 시스템은 서로 다른 분야에서 사용되고 있는 기개발된 정보검색시스템을 통한 검색하거나, 같은 분야의 시스템이라도 스키마가 다를 경우에 이를 사용자가 마치 하나의 시스템에서 검색하는 것과 같은 통합검색을 수행할 수 있도록 해준다. 본 시스템은 통합메타데이터베이스와 원천서버간의 스키마 매핑을 지원하는 원천서버관리기, 메타데이터를 등록하고 원천서버의 정보와 통합 메타데이터간의 매핑을 관리하고 지원하는 통합메타데이터 관리기, 통합검색을 위한 사용자 신의를 각 원천서버에 적합한 질의로 생성하여 처리하는 분산질의 처리기, 검색된 결과를 통합하여 사용자 화면으로 출력하기 위해 HTML 문서로 변환하는 분산 데이터 셋 관리기, 그리고 통합검색을 위한 통합검색 엔진으로 구성되어 있다. 통합메타데이터는 본 시스템의 일부분인 메타데이터 등록기를 이용하여 ISO/IEC 11179에서 정의된 표준화된 절차고 등록되었다고 가정하여 사용하였다. 사용자는 하나의 통합시스템에서 검색하는 것과 같이 통합검색 화면에서 검색대상 시스템을 선정하고 기본검색과 상세검색을 수행하며, 분야별 혹은 기관별로 검색하고 결과를 볼 수 있도록 하였다. 본 시스템은 KRISTAL-2002 시스템을 기반으로 Visual C++와 C++ CGI를 이용하여 리눅스 상에서 개발되었으며 6개의 서로 다른 데이터베이스fmf 이용하여 실험, 검증하였다. In this paper, we propose an integrated information retrieval system for distributed multiple KRISTAL-2002 systems by using the metadata information. This system integrates current systems for different areas or systems for the same area with the different schemas so that the users can get the answers by once from the whole systems. The proposed system composes of the Source Server Manager(SSM) supporting the mapping between the integrated metadata database and source server, the Integrated Metadata Manager(ISM) for registering and managing the metadata and schema mapping, the Distributed Query Processor (DQP) for processing the user query into the source server query, the Distributed Data Set Integrated Manager(DDSIM) for transforming the total retrieval results by merging to the HTML format, and the integrated retrieval engine for managing the query results. It is assumed that the integrated metadata follows ISO/IEC 11179 metadata registration procedure with the metadata registry system which is a subsystem of the proposed system. There are two kinds of queries for users; the basic query and the detailed query. The users may select the databases or organizations for results by their own choices before giving the queries. The proposed system has been developed over KRISTAL-2002 systems with <TEX>$Visual C^{++}\;and\;C^{++}-CGI$</TEX> and tested and verified with the six database systems.

Their First Encounter

Abstract This article discusses the response of at-risk students to their initial library orientation. By presenting an entertaining yet informative session, students will be quickly put at ease. The goal of this type of orientation is to promote the library's resources and services, address basic queries, and encourage students' return in a non-threatening, entertaining manner. The article includes a review of the literature on the need for library orientation for non-users, a description of a summer success program on campus, the process involved in putting the library component together, the program's design, and a preliminary assessment of the program.

SemQuery: semantic clustering and querying on heterogeneous features for visual data

The effectiveness of content-based image retrieval can be enhanced using heterogeneous features embedded in the images. However, since the features in texture, color, and shape are generated using different computation methods and thus may require different similarity measurements, the integration of the retrievals on heterogeneous features is a nontrivial task. We present a semantics-based clustering and indexing approach, termed SemQuery, to support visual queries on heterogeneous features of images. Using this approach, the database images are classified based on their heterogeneous features. Each semantic image cluster contains a set of subclusters that are represented by the heterogeneous features that the images contain. An image is included in a semantic cluster if it falls within the scope of all the heterogeneous clusters of the semantic cluster. We also design a neural network model to merge the results of basic queries on individual features. A query processing strategy is then presented to support visual queries on heterogeneous features. An experimental analysis is conducted and presented to demonstrate the effectiveness and efficiency of the proposed approach.

Partial Entity Structure: A Compact Boundary Representation for Non-Manifold Geometric Modeling

Non-manifold boundary representations have become very popular in recent years and various representation schemes have been proposed, as they represent a wider range of objects, for various applications, than conventional manifold representations. As these schemes mainly focus on describing sufficient adjacency relationships of topological entities, the models represented in these schemes occupy storage space redundantly, although they are very efficient in answering queries on topological adjacency relationships. To solve this problem, in this paper, we propose a compact as well as fast non-manifold boundary representation, called the partial entity structure. This representation reduces the storage size to half that of the radial edge structure, which is one of the most popular and efficient of existing data structures, while allowing full topological adjacency relationships to be derived without loss of efficiency. In order to verify the time and storage efficiency of the partial entity structure, the time complexity of basic query procedures and the storage requirement for typical geometric models are derived and compared with those of existing schemes.

Dynamic planar convex hull operations in near-logarithmic amortized time

We give a data structure that allows arbitrary insertions and deletions on a planar point set P and supports basic queries on the convex hull of P , such as membership and tangent-finding. Updates take O (log 1+ε n ) amori tzed time and queries take O (log n time each, where n is the maximum size of P and ε is any fixed positive constant. For some advanced queries such as bridge-finding, both our bounds increase to O (log 3/2 n ). The only previous fully dynamic solution was by Overmars and van Leeuwen from 1981 and required O (log 2 n ) time per update and O (log n ) time per query.

VARIANT: A System for Terrain Modeling at Variable Resolution

We describe VARIANT (VAriable Resolution Interactive ANalysis of Terrain), an extensible system for processing and visualizing terrains represented through Triangulated Irregular Networks (TINs), featuring the accuracy of the representation, possibly variable over the terrain domain, as a further parameter in computation. VARIANT is based on a multiresolution terrain model, which we developed in our earlier research. Its architecture is made of a kernel, which provides primitive operations for building and querying the multiresolution model; and of application programs, which access a terrain model based on the primitives in the kernel. VARIANT directly supports basic queries (e.g., windowing, buffering, computation of elevation at a given point, or along a given line) as well as high-level operations (e.g., fly-over visualization, contour map extraction, viewshed analysis). However, the true power of VARIANT lies in the possibility of extending it with new applications that can exploit its multiresolution features in a transparent way.

Querying Semistructured Heterogeneous Information

Semistructured data has no absolute schema fixed in advance and its structure may be irregular or incomplete. Such data commonly arises in sources that do not impose a rigid structure (such as the World-Wide Web) and when data is combined from several heterogeneous sources. Data models and query languages designed for well structured data are inappropriate in such environments. Starting with a “lightweight” object model adopted for the TSIMMIS project at Stanford, in this paper we describe a query language and object repository designed specifically for semistructured data. Our language provides meaningful query results in cases where conventional models and languages do not: when some data is absent, when data does not have regular structure, when similar concepts are represented using different types, when heterogeneous sets are present, and when object structure is not fully known. This paper motivates the key concepts behind our approach, describes the language through a series of examples (a complete semantics is available in an accompanying technical report [23]), and describes the basic architecture and query processing strategy of the “lightweight” object repository we have developed.

An open abstract-object storage system

Database systems must become more open to retain their relevance as a technology of choice and necessity. Openness implies not only databases exporting their data, but also exporting their services. This is as true in classical application areas as in non-classical (GIS, multimedia, design, etc).This paper addresses the problem of exporting storage-management services of indexing, replication and basic query processing. We describe an abstract-object storage model which provides the basic mechanism, ' likeness ', through which these services are applied uniformly to internally-stored, internally-defined data, and to externally-stored, externally-defined data. Managing external data requires the coupling of external operations to the database system. We discuss the interfaces and protocols required of these to achieve correct resource management and admit efficient realisation. Throughout, we demonstrate our solutions in the area of semi-structured file management; in our case, geospatial metadata files.

Computing for Historians: An Introductory Guide

Part 1 Background: history and computing - the second revolution computer systems - an introduction word-processing for historians. Part 2 Census - an introductory historical database: structured sources using a database - basic queries enriching the information - coding and structure simple statistics - description, correlation and sampling. Part 3 Sources, resources and approaches: more advanced database techniques - collective biography tables and spreadsheets - voting and the census using existing databases - economic perspectives linking sources - comprehensive analysis of a community beyond the database - text analysis, hypertext and computer-assisted learning. Appendices: the Gorbals census dataset CD-ROM and on-line historical bibliographies.

A methodology for database system performance evaluation

This paper presents a methodology for evaluating the performance of database management systems and database machines in a multiuser environment. Three main factors that affect transaction throughput in a multiuser environment are identified: multiprogramming level, degree of data sharing among simultaneously executing transactions, and transaction mix. We demonstrate that only four basic query types are needed to construct a benchmark that will evaluate the performance of a system under a wide variety of workloads. Finally, we present the results of applying our techniques to the Britton-Lee IDM 500 database machine

Residual (API) Analysis and the Private Value of Information

The purpose of this paper is to investigate the relationship between the private value of information (PVI) and the API metric. The question was probably first raised by Beaver and Dukes [1972]. The issues involved are of interest, since they touch upon the basic query: why residual analysis? As has been noted by Gonedes and Dopuch [1974] and Marshall [1975], residual analysis generally cannot resolve the question of finding the socially optimal accounting alternative; that much has at least been agreed upon. Regarding the issue of relating API metrics to PVI, the state of our present knowledge is much less clear-cut. Marshall [1975, p. 103] has shown that . . . the API cannot always be relied on to measure correctly either private information value or association. Marshall develops a simple numerical example to make the point. However, Marshall does not consider the problem of finding sufficient conditions. This would appear to be a more substantive question, since it almost goes without saying that there generally cannot be a one-to-one correspondence between the PVI and the API. It also should be clear that unless the sufficiency problem is understood, one will have little, if any, idea whether the API is a meaningful metric. In the accounting literature, it appears that an API metric can be given two conceptually distinct interpretations-first, as an ordinary measure of association or correlation between signal(s) and the unexpected components of returns (residuals). The association can be contemporaneous or predictive, and many, if not most, studies consider both of these

Dimensions of welfare in a Comparative Scandinavian Study

as a word has many connotations. In the English language and particularly in its American variant the word brings to mind the notion of public assistance. Something of the same idea is present in the most common usage of the term welfare A society with a high amount of public expenditure in the fields of social security, education and health is characterized as a state. Here the word refers to the state of need-satisfaction in a national population. The aim has been to measure and describe or the state of need-satisfaction in Denmark, Finland, Norway, and Sweden. Welfare as a concept denoting the state of need-satisfaction in a population is usually studied and described by some system of social indicators. The indicators refer to different components or aspects of welfare. However, indicators of are not merely some kind of variables. They are explicitly value-oriented, and as such concerned with the good and bad life. Hence, indicators of may also be labeled value-dimensions or values. In developing a system of values two problems in particular are pressing. The first and very basic problem concerns the source of these values, and the basic query is from where we get the values. In current debates there have, roughly speaking, been two opposing views. According to one view values or dimensions should be established by studying objective facts, and in particular, people's goal-directed activities and conditions under which people suffer. In the last analysis, then, the values are established by the researcher irrespective of whether he works in collaboration with the people studied or not. According to another view the values have to be established by studying the subjective per-

MUSEUM SPECIMEN RECORD DATA STORAGE AND RETRIEVAL

SummaryExamples of problems that arise from the present lack of an efficient information service for specimen‐label data are reviewed. Deficiencies exist in the guidance given to collectors, the provision of local distribution data for environmental and other studies, and in the support given the monographers in locating Types. Basic queries such as on the fauna and flora of a particular area mostly cannot be answered directly, although the data lie close at hand. With respect to label information the museum or herbarium is a data crypt rather than a data bank. Computer‐based data‐banking offers a solution to these fundamental problems. Selected items of label data can be retrieved and sorted for output in catalogues or lists by the computer, along with tallies and distribution maps. The steps by which one may achieve this are described, together with a review of the chief kinds of computer program‐system and sources of advice. The need for careful systems analysis and international standards for recording the data is emphasised.

How Teachers Perceive the Relation Between School and Society

A SERIES OF studies of the school as a social institution was begun at the Institute of Sociological Research early in 1969. The studies are guided by two basic queries: (1) What is the nature of the relationship between the dynamics of society and of the school; in other words, how can a school system that generally tends toward rigidity adapt itself to the demands of a changing society? (2) How do differentiation and hierarchies related to schooling evolve in a society that is striving toward egalitarianism? These problems are approached in our research from several angles and treated at different levels (e.g., the levels of leaders of the society, parents, the school, teachers) by a variety of methods, ranging from the in-depth interview and content analysis to the sociological survey and specially designed procedures of measurement. Two large-scale investigations served as a starting-point. On the one hand, we have described the workings of the educational system of Hungary with the aid of statistical data about scholastic achievement. Using a national sample, stratified by type of locality and type of school, we obtained school marks for approximately 70,000 children in 2000 classes. Our purpose was to learn what influence school characteristics, the social milieu of the child,

An Optimized Frequent Item Query Algorithm for Uncertain Streaming Data

Recently, sensors are used in many fields, and the data generated are uncertain streaming data. Frequent item query is one of the most query primitives in this kind of data. In this paper, we study frequent item query for uncertain streaming data. First, we propose a basic frequent item query algorithm for uncertain streaming data basic on slide window, and then propose an optimized algorithm. Experiments show that, the proposed optimized algorithm can reduce running time and memory usage while querying frequent item for uncertain streaming data generated by sensors

Some Basic Queries Respecting World Regionalism

IN THE opinion of many, the globe, and not merely the nation or even the continent or oceanic area, has become the areal unit within which a host of planning and functional activities relating to administration and well-being must be carried on. Regionalism on a world scale has been actively and widely advocated recently, especially in the United States, as an aid-in fact, an indispensability-in conducting these tasks. It is mentioned especially as an aid in world unity as well as administration. Certain assumptions, which are sometimes lost sight of, underlie the whole matter of post-war world organization. The more basic of these will be stated as a background for the critical examination of world regionalism to follow.