• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.04a
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• pp.118-125
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• 1992

The ground deformation due to the tunnel excavation is dependent on various factors such as ground condition, geometry of the tunnel, excavation method, installation of support members, construction condition of each excavation stage, etc. And the distance from the facing effects significantly the stress conditions of the supported and unsupported ground due to the 3-dimensional structural nature of the excavated tunnel. The concept of ground characteristic line has been applied to properly consider the loading condition given by staged tunnel excavation so that the imaginary supporting pressure is applied against the surface of excavated ground. Discussions on the results of the performed finite element analysis were mainly made with respect to the ground settlement, tunnel displacement, earth pressure, stress mobilized in supporting members.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.316-321
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• 2008

As people are aging, there are changes about biological psychological sociological. For these reasons, it will arise that changing body size, decreasing power of body, shrinking of living, becoming dull the senses, and feeling alienation loneliness sense of distance about society. Many studies have been done to give residential space supporting older adults' living. Recently many ubiquitous technologies are being development and applied to residential space. The purpose of this study was to classified ubiquitous services by housing supporting concept and older people's physical, psychological and social characteristics and to identify needs for ubiquitous services by older adults. The researches developed a survey instrument and collected the data from 260 people in July to August, 2008 who were more than 40 years old. The results of this study found that residents' current needs and suggested ubiquitous services in future residential environment for older adults.

• Journal of the Korean Ceramic Society
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• v.37 no.7
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• pp.713-720
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• 2000

The biaxial fracture behavior of alumina ceramics was studied using ball-on-3-ball test. The polished surfaces of alumina specimens were indented at 0mm, 1mm, 2mm, 3mm apart from the center of the specimen along path A, passing between the two supporting balls from the center of the specimen, and along path B, passing above the three supporting balls from the center of the specimen. The fracture strength of the indented specimens was measured using the ball-on-3-ball test, a kind of biaxial strength test. The fracture strength increased with increasing the distance from the center to indented position. The fracture strength of the specimen indented along path B was higher than that of the specimens indented along path A. It was presented that the fracture caused by tangential stress rather than radial stress when the indented positions are 1mm and 2mm from the center of the specimen. This phenomenon was in good agreement with FEM analysis.

• IE interfaces
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• v.14 no.1
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• pp.39-46
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• 2001

The purpose of this paper is to develop a vehicle routing supporting system with various restrictions using a digital map. The position data and the distance data are obtained from the digital map. The system is composed of input module, execution module, output module. In the input module, we can select options, which correspond to various restrictions and criteria for the vehicle routing problem to be solved. The execution module solves the selected problem in a relatively short time and suggest a good heuristic solution to the dispatcher, and also allows the dispatcher to easily modify the solution. The vehicle routes are displayed on the digital map. The application and the effectiveness of the system were shown through two case studies.

• Journal of The Korean Association of Information Education
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• v.13 no.2
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• pp.135-144
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• 2009

The purpose of this study was to explore strategies for promoting distance education program and for providing total information for teachers about curriculum of distance educational training institute. In 2007, there were 65 institutes of distance education training, but we don't have enough information about curriculum of the institutes. To analyze curriculums of the institutes, it had been selected 33 institutes of 65, and 567 of performance training programs, 317 of optional programs, and 23 of free training programs. The following results were obtained : (1) It calls for easy accessibility to distance educational training institutes (2) It has to overcome biased status that private institutes have more courses than government institutes'. (3) It will be needed to make diverse courses for teacher's capabilities. (4) It calls for course development of several subject matters (5) It will be needed to maintenance for running course continuously. (6) It has to make supporting plan for excellent courses by government.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.3
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• pp.253-260
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• 2016

This paper proposes a planar Log-Periodic Dipole Array(LPDA) antenna with light-weight supporting structure for installing on an aircraft. The proposed antenna is designed by applying a planar skeleton supporting structure that has light-weight for an aircraft and is capable of withstanding structural vibration. The material of the planar skeleton supporting structure is a Polyether ether ketone(Peek) which has excellent characteristics on strength and temperature. The proposed antenna is fabricated by attaching the radiating elements of the LPDA on both sides of the supporting structure. The changed input impedance due to the dielectric material of the supporting structure was compensated for by controlling the distance and length of several radiating elements. The 10-dB return loss bandwidths of the designed planar LPDA antenna with light-weight supporting structure are obtained as 0.4~3.1 GHz(7.3:1) in the simulation and 0.41~3.5 GHz(8.2:1) in the measurement. The average gains in 0.5~3 GHz band are 6.77 dBi in the simulation and 6.55 dBi in the measurement. Therefore, we confirm that the designed antenna is appropriate to be installed on an aircraft due to its light-weight structure and wideband directional radiation characteristics.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.367-369
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• 2001

GSPA(Generic Shortest Path Algorithm)은 각종 정보통신 네트워크 상에서 멀티미디어 정보전송시 요구되는 QoS 기반의 라우팅을 위한 새로운 라우팅 알고리즘이다. 전체적인 동작은 원시노드(Source Node)에서 목적노드(Destination Node) 사이에서 이전 단계의 재귀호출에서 찾은 최단 경로를 기준으로 해서 이웃 노드들을 대상으로 재귀호출을 통해서 QoS 요구조건을 만족하는 경로정보를 기록하면서 최단 경로를 찾는 알고리즘이다. GSPA는 기존 Distance Vector 알고리즘이 경로를 설정하기 위해 많은 시간과 대역폭을 낭비하며 네트워크 형상이 수시로 변경될 때 “Counting to Infinity”현상을 발생시키는 단점을 보완하고, Link-State 데이터 베이스를 이용해서 함수 재귀호츨을 통해서 최단 경로를 찾아냄으로써 구현하기가 쉬운 알고리즘이다. 또, Distance-Vector와 Link-State 알고리즘의 장점을 수용하였으며, 이 알고리즘을 분산 네트워크 환경에서 동작하도록 수정하면 분산 네트워크 환경에서의 Hierarchical Routing, Multi-Path Routing, QoS Routing을 위한 기본 알고리즘으로 매우 좋은 특성들을 가지고 있다. 본 논문에서는 이 알고리즘을 소개하고 간단한 예를 통해 기본 동작에 대해 살펴본다.

• Journal of information and communication convergence engineering
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• v.19 no.3
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• pp.161-165
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• 2021

Since the first commercialization of beacon-based services in 2011, various services have been provided to improve Bluetooth performance, and research has been conducted to accurately recognize user locations using beacons. The various measurement methods of indoor positioning systems (IPS) include methods using receiver signal strength indicator (RSSI) the strength of which varies greatly in accuracy depending on whether there are obstacles such as cement walls or doors. In this paper, we present a method to provide accurate positioning services even in the presence of obstacles in indoor spaces. To this end, we connect the HM-10 module supporting the beacon with Arduino Uno, to place beacons in three directions in real-world indoor space, and derive an optimal trilateration equation. Based on the derivation, we select the optimal expression for calculating the distance between the beacon and the moving station and use it to verify the coordinate determination for the moving station.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.133-136
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• 1998

Supporting decision-makers involves not only functions of conventional DSS such as problem identification, alternative generation and selection but also education and business processing. The purpose of this paper is to propose Decision-Maker Support System (DMSS) that comprehensively supports decision-makers who should enhance their decision quality. The DMSS consists of three core subsystem: distance learning system, conventional DSS and ERP system.

• Knowledge Management Research
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• v.2 no.1
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• pp.133-144
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• 2001

Clusters mean geographic concentrations of interconnected companies and institutions in a particular field. Geographic, cultural, and institutional proximity provides companies with special access, closer relationships, better information, powerful incentives, and other advantages that are difficult to tap from a distance. And clusters are the knowledge-sharing networks which are composed of co-existence of related industries and supporting industries, sophisticated demand, sponsor of various exhibitions and events, liaison of peripheries and clusters, liaison of clusters and clusters, and governments' willingness for promoting clusters' development.