• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.216-219
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• 1997

분산 데이터베이스에서의 통신량을 줄이기 위한 기법과 관련한 많은 연구가 수행되고 있으며, 이러한 연구는 주로 데이터베이스 설계 초기에 고려되는 파일의 배치에 대한 문제를 다루고 있다. 이러한 파일 배치 문제에서는 분산 데이터베이스 상황을 가정하고, 공식화(formulation)한 후 이에 대한 해법을 제시하는 방식을 취하는 것이 일반적이다. 본 연구에서는 하나의 파일이 다른 지점에 있는 파일을 참조하는 경우 두 파일에 대한 접근량을 줄이기 위한 방법을 제안함으로써 분산 데이터베이스의 물리적 설계의 최적화를 도모하였다. 본 연구에서는 기존의 방법과는 달리 참조정보를 요하는 참조 파일(referential file)을 추가함으로써 두 지점간의 통신량을 줄이고자 하는 방안을 제시하였으며, 이 때 참조 파일의 종류는 참조하는 레코드의 수를 유지하는 방법과 참조 여부에 관한 정보만 유지하는 두 가지 방법을 모두 고려하였다. 본 연구에서는 기존의 방식과 본 연구에서 제안한 두 가지 방법간의 통신비용을 계산함으로써 본 연구의 타당성을 검증하였다. 이때 참조 무결성을 유지하는 대표적인 세 가지 제약조건, 즉 Cascade delete, Restricted, Nullify를 대상으로 분석함으로써 이와 관련된 대다수의 프로토콜에서 본 연구에서 제안한 방법의 효용성을 입증코자 했다. 이를 위해 필요한 공식들을 유도해 내는 작업도 논문에서 중요하게 다루었다. 이 연구는 분산 데이터베이스 설계시 통신량을 줄이는 중요한 고려 요소로 활용될수 있을 것이다.

• The Journal of Society for e-Business Studies
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• v.8 no.1
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• pp.103-111
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• 2003

Nowadays XML is used for exchanging information in e-Commerce, especially B2B. Necessity of XML DBMS has being increased to efficiently process XML data. So a lots of database products for supporting XML are rapidly appeared in the market. In this paper, we made an XML DBMS system based on Generic Data Model. First we developed XML Adaptor based on Generic Data Model and added it on relational DBMS for developing XML DBMS. XML Adaptor is composed of Query Convertor and XML Repository System. The Query Convertor parse commands that are for XML data manipulation and then call the relevant component of XML Repository System for relational database operation. The XML Repository System handles relational database operations such as create, delete, store, and etc. In this way we can use a relational DBMS for manipulation XML data. Therefor we can build more economically XML DBMS.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.3
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• pp.59-80
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• 1997

Designing highly survivable interoffice telecommunication networks is considered. The problem is formulated as a minimum-cost network design problem with three node connectivity constraints. These valid and facet-defining inequalities for the convex hull of the solution are presented. A branch and cut algorithm is proposed based on the inequalities to obtain the optimal solution. With the lower bound by the cutting plane algorithm, a delete-ink heuristic is proposed to otain a good upper bound in the branch and bound procedure. The effeciveness of the branch and cut algorithm is demonstrated with computational results for a variety of problem sets : different lower bounds, two types of link costs and large number of links. The cutting plane procedure based on the three inequalities provides excellent lower bounds to the optimal solutions.

• International Journal of Contents
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• v.6 no.4
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• pp.22-29
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• 2010

In flash memory, many previous garbage collection methods only merge blocks statically and do not consider the contents of buffer. These schemes may cause more unnecessary block erase operations and page copy operations. However, since flash memory has the limitation of maximum rate and life cycle to delete each block, an efficient garbage collection method to evenly wear out the flash memory region is needed. This paper proposes a memory compaction scheme based on block-level buffer for flash memory. The proposed scheme not only merges the data blocks and the corresponding log block, but also searches for the block-level buffer to find the corresponding buffer blocks. Consequently, unnecessary potential page copying operations and block erasure operations could be reduced, thereby improving the performance of flash memory and prolonging the lifetime of flash memory.

• Journal of Computing Science and Engineering
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• v.3 no.1
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• pp.15-26
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• 2009

Given an n-length text T over a $\sigma$-size alphabet, we present a compressed representation of T which supports retrieving queries of rank/select/access and updating queries of insert/delete. For a measure of compression, we use the empirical entropy H(T), which defines a lower bound nH(T) bits for any algorithm to compress T of n log $\sigma$ bits. Our representation takes this entropy bound of T, i.e., nH(T) $\leq$ n log $\sigma$ bits, and an additional bits less than the text size, i.e., o(n log $\sigma$) + O(n) bits. In compressed space of nH(T) + o(n log $\sigma$) + O(n) bits, our representation supports O(log n) time queries for a log n-size alphabet and its extension provides O(($1+\frac{{\log}\;{\sigma}}{{\log}\;{\log}\;n}$) log n) time queries for a $\sigma$-size alphabet.

• Proceedings of the KSRS Conference
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• v.2
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• pp.695-697
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• 2006

Elshayal $Smart{\copyright}$ software is an almost First Arabian GIS $software{\copyright}$ which completely developed by Arabian developers team and independent of any commercial software package. The software current Features are View and Edit shape files, build new layers, add existing layers, remove layers, swap layers, save layers, set layer data sources, layer properties, zoom in & zoom out, pan, identify, selecting features, invert selection, show data table, data query builder, location query builder, build network, find shortest path, print map, save map image, copy map image to clipboard, save project map, edit move vertex, edit move features, snap vertexes, set vertex XY, move settings, converting coordinate system, applying VB script, copy selected features to another layer, move selected features to another layer, delete selected features, edit data table, modify table structure, edit map features, drawing new features, GPS tracking, 3D view, etc... The software expected Features are: Viewing raster image and image geo-referencing, read other map formats such as DXF Format and Tiger Line Format.

• Communications for Statistical Applications and Methods
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• v.11 no.2
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• pp.399-411
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• 2004

A common method of handling nonresponse in sample survey is to delete the cases, which may result in a substantial loss of cases. Thus in certain situation, it is of interest to create a complete set of sample values. In this case, a popular approach is to impute the missing values in the sample by the mean or the median of responders. The difficulty with this method which just replaces each missing value with a single imputed value is that inferences based on the completed dataset underestimate the precision of the inferential procedure. Various suggestions have been made to overcome the difficulty but they might not be appropriate for public-use files where the user has only limited information for about the reasons for nonresponse. In this note, a multiple imputation method is considered to create complete dataset which might be used for all possible inferential procedures without misleading or underestimating the precision.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.565-569
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• 1993

In this paper, a specified number of actuators are selected from a given set of admissible actuators. The selected set of actuators is likely to use minimum control energy while required output variance constraints are guaranteed to be satisfied. The actuator selection procedure is an iterative algorithm composed of two parts; an output variance constrained control and an input variance constrained control algorithm. The idea behind this algorithm is that the solution to the first control problem provides the necessary weighting matrix in the objective function of the second optimization problem, and the sensitivity information from the second problem is utilized to delete one actuator. For variance constrained control problems, by considering a dual version of each control problem an efficient algorithm is provided, whose convergence properties turn out to be better than an existing algorithm. Numerical examples with a simple beam are given for both the input/output variance constrained control problem and the actuator selection problem.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.10a
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• pp.18-18
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• 1998

현재 대형 조선소에서는 선박에 사용하고 있는 수많은 부재들을 고가이고, 고급인력을 필요로 하는 WORK-STATION에서 구동되는 대형의 선박전용 프로그램 등에 의하여 부재생성 및 네스팅을 하고 있다 그러나 중소형 조선소의 경제적, 기술적인 사정으로 고가의 장비와 고급인력의 확보가 어려운 실정이다. 따라서 본 연구에서는 널리 보급되어 있는 PC에서 사용 가능한 파라매트의 매크로에 의한 부재생성과 부재의 스트리핑 프로그램을 개발하였다. 본 논문의 주요 내용은 다음과 같다. 첫째, 파라매트릭 매크로기법을 이용하여 빠르고 정확하게 스티프너를 생성하기 위하여 라이브러리를 구축하고, 생성된 스티프너를 확인할 수 있는 프로그램을 개발하였다. 둘째, 스티프너들을 강재의 효율이 좋게 배치하기 위하여 AUTO, INSERT, DELETE, MOVE 기능이 포함된 자동배치 프로그램을 개발하였다. 셋째, 구축된 부재외형들을 라이브러리에 등록하고, 생성된 부재와 강재에 배치된 부재들의 관리를 위하여 데이터베이스 프로그램을 개발하였다. 개발된 프로그램에 의하여 중소형 조선소에서도 컴퓨터에 의한 정확한 부재의 생성과 부재의 자동배치에 의하여 강재수율을 높일 수 있을 것으로 사료된다.

• Korean Journal of Child Studies
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• v.28 no.4
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• pp.73-95
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• 2007

Causal relationships of kindergarteners' phonological awareness and processing to their ability to read words was investigated with the participation of 289 4- to 6-year-old children attending three kindergartens in Busan. Results showed gradual growth in reading ability with age. Children performed best in reading words and poorest in reading low frequency letters. They showed continuous development in skills of syllable deletion, phoneme substitution, phoneme insertion, phonological memory and naming. Discontinuous development was found in counting syllables. Longer syllables were difficult to count, and middle syllables of 3 syllable words were hard to delete. Children had poor perception of final consonants of Consonant-Vowel-Consonant syllables. Children's phonological awareness and processing were latent variables strongly related to ability to read words written in Hangul.