• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2298-2309
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• 2000

This paper proposes the multidimensioa! nested attribute indexing techniques (MD- NAI) in object-oriented databases using a multidimensional index structure. Since most conventional indexing techniques for object oriented databases use a one-dimensional index stnlcture such as the B-tree, they do not often handle complex qUlTies involving both nested attributes and class hierarchies. We extend a tunable two dimensional class hierachy indexing technique(2D-CHI) for nested attributes. The 2D-CHI is an indexing scheme that deals with the problem of clustering ohjects in a two dimensional domain space that consists of a kev attribute dOI11'lin and a class idmtifier domain for a simple attribute in a class hierachy. In our extended scheme, we construct indexes using multidimensional file organizations that include one class identifier domain per class hierarchy on a path expression that defines the indexed nested attribute. This scheme efficiently suppoI1s queries that involve search conditions on the nested attribute represcnted by an extcnded path expression. An extended path expression is a one in which a class hierarchy can be substituted by an indivisual class or a subclass hierarchy in the class hierarchy.

• Spatial Information Research
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• v.14 no.2 s.37
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• pp.245-260
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• 2006

A practical use of the location information and user requirement are increased in a mobile environment which supports the portability. And Various service which GIS is related with a Spatial DB have been processed. Generally, logical relation of a traffic network which organizes the Road DB uses a basic node-link structure. In this way, Designed structure can not be flexible at various model apply and are not efficient with a database retrieval in a maintenance management side. In this research, We supplement with the problem of a existing network model and the limitation of the building through the design of a network model which uses dynamic segmentation. And we tried to implement efficient hierarchy model at the retrieval of the network and presentation. Designed model supports a stage presentation of various level and a hierarchy entity relation and We are expected to supplement a network spatial modelling function which the GIS has.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.115-121
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• 1995

The Conventional database management system is not applicable because of their inadequate performance and difficulty of CAD database that is dependant to hierarchical structure and to repeat accesses of large data. For effective management and easy tool integration of CAD database, hierarchy Interface System(HIS) is designed and GROCO(Graph Representation fOr Complex Objects) Model is presented. Hierarchy Interface System which is composed of two subsystems of a configurator and a converter is designed for the interface between a conventional database management system and CAD tools. GROCO Model is a directed cyclic graph having five node-types for representing semantics and supports efficiently CAD database characters having a hierarchical structure of complex objects.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1199-1208
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• 2013

In recent years, the development of application programs for distribution system analysis and control has been essential part for distribution management system (DMS). In this paper, we propose the common database for application programs of distribution management system. The proposed database model has several characteristics as followings. First, the proposed database model is designed for the common use of almost the whole distribution application software. The static equipment model and dynamic type tables are mixed and the parallel table structure is applied. Second, the linked list structure of database are used for the fast processing of applications. The database model includes the hierarchy and non-hierarchy distribution system structure. Third, the reduction method of distribution database is applied. For this, we present the network reduction rules. The basic concept of reduction rules are the electrical unification of successive line section which has not lateral branches and the removal of simple lateral branches which has no devices and other laterals. Proposed database model is tested for the Jeju system of Korea Electric Power Corporation (KEPCO). Through the test, we verified that the proposed database structure can be effectively used to accomplish the distribution system operation.

• Smart Structures and Systems
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• v.29 no.5
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• pp.747-755
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• 2022

Hierarchical structure parameters, proposed in She-Leveque model, are investigated for velocity components obtained from different flow types over a large range of Reynolds numbers 255 < Re_𝜆 < 720. The values of intermittency parameter 𝛽, with respect to a fixed velocity component, are observed nearly same for all four types of turbulence. The parameter 𝛾, for streamwise velocity components is nearly the same but significantly different for vertical components in different flows. It is also observed that for both parameters, an obvious relation between the longitudinal and transverse components 𝛽_T < 𝛽_L (and 𝛾_T < 𝛾_L) always holds. However, the difference between 𝛽_L and 𝛽_T is found very small in all types of turbulent flows, we studied here. It is evidenced that at low Reynolds numbers, the deviations from K41 scaling are mainly due to the most intense structures and slightly because of more heterogeneous hierarchy of fluctuation structures. However, at higher Reynolds numbers the deviations seem as a consequence of the most intense structures only. Over all, the study suggests that the hierarchy parameter 𝛽 may be consider as a universal constant.

• IE interfaces
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• v.2 no.1
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• pp.69-78
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• 1989

The objective of this study is to establish a hierarchical structure for Quality of Service Management (QOSM) from subsriber's viewpoint. First, We construct the hierarchy of the QOSM items. These items are derived from the CCITT concepts and the present Korean Telecommunication Authority(KTA) system. Then QOS performance indicators which consists of the lower levels of the hierarchy and the weight value is constructed. Finally, an evaluation method of the QOS is presented. It is expected that this study offers an evaluation method of network performance and efficiency of operation and maintenance for telecommunication facilities.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.325-334
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• 2009

The aims of this study is to suggest the strategic development plan of Ulsan Port using SWOT/AHP method. In order to do this, 16 detailed factors for SWOT Matrix were identified both from previous studies and from brainstorming professionals of the port and these made into a 3 level hierarchy structure. AHP method identified the relative weight of SWOT level as threat(0.311), opportunity(0.259), strength(0.218) and weakness(0.212), also the composite relative weight of detailed factors as recession of global economy(0.125), strengthening of economic function in port(0.085), insufficiency of port facilities(0.080) and a government regulation of port management(0.075). As a result, the study suggests S/T strategy, W/T strategy, S/O strategy, W/O strategy as a strategic development plan of the Ulsan Port.

• The Mathematical Education
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• v.43 no.1
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• pp.70-85
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• 2004

Comparing to the other subject, hierarchy among mathematical contents is strong from the perspective of knowledge order as grades go up. That is, the knowledge that students already have learned, are learning and will learn are closed related from grade to grade. We expect students to be proactive and creative in studying mathematics, which is the goal of 21th century, analyzing their. knowledge structure based on the hierarchy of knowledge through assessment. Especially, using computer system we provide students with substantial feedback for the assessment as well as objective validity is increased along with speedy and exact process in a bid to help students' mathematical understanding grow. This paper seeks to analyze the assessment data by applying knowledge spaces to computer system and develops efficient methods based on the analyzed results, to diagram each student's knowledge structure.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.2
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• pp.195-204
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• 2010

As the throughout of transshipment oil cargo in Korea has been increasing, the importance and competition of the oil hub port has also been increasing. The aim of this study is to suggest how the factors influence the competitiveness of the oil hub port based on the specialists' opinions. For doing this, the evaluating factors were obtained from both previous studies and brainstorming of the professionals from the oil hub port. These were divided into groups by the ‘KJ method' according to 5 criteria and were made into a 3 level hierarchy structure. The ‘AHP method' identified the relative importance of factors and trends from the preferences of the specialists. This study presents the factors influencing the competitiveness of the oil hub port.

• Journal of Korean Society for Quality Management
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• v.33 no.2
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• pp.1-12
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• 2005

An extensive literature review has been made in this paper to build the evaluation hierarchy structure for the certification of electronic commerce services. In building the evaluation hierarchy structure, major candidate evaluation factors are selected by bench marking the various certification practices, including the Malcolm Baldrige award, ISO9000, and BSC(balanced scorecard) techniques. This paper deployed principal component analysis and factor analysis techniques to develop a statistically solid and systematic evaluation model. The final evaluation model, as presented in this paper as a model for the certification of electronic commerce services, produces a numeric score on the 100% scale, which can be served as a metric for the certification decision. The AHP technique was used in converting the various qualitative and quantitative evaluation values into a single measure for the certification decision.