• 대한산업공학회지
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• 제21권4호
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• pp.463-477
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• 1995

This paper presents a decision model that will estimate the expected number of failed units in a repair facility in accordance with the varying demand, and determine the required number of personnel for repairing components. The demand is related to the failure process which follows a reliability growth phenomenon in service. The information in this paper is useful for selecting appropriate scheduling rules and spares stocking policies. SIMAN and FORTRAN were used for computing the time dependent performance measures in the repair facility. The numerical integration method that is presented in this paper will provide accurate performance measures with any dynamic pattern of demand, service rates, and any number of servers.

• 전력전자학회논문지
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• 제22권3호
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• pp.223-230
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• 2017

A low-cost BLDC motor with hall sensor is used to drive the position control of a facility security monitoring system in this paper. Low measurable frequency of the hall sensor signal in low-speed regions results in difficulty in obtaining accurate speed detection and position control. To improve system control performance, we propose a variable gain of position controller and stop mode control scheme according to the motor speed and error position with pre-set deceleration time. The proposed stop mode control scheme is activated around the stop position to forcibly move the BLDC motor to the stop position in low speed. In the proposed stop mode, the motor current is controlled by the actual speed with the reference rotating angle. The control performance of the proposed position control is verified through experiments at the actual rail guided facility security monitoring system.

• 방사성폐기물학회지
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• 제21권3호
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• pp.329-345
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• 2023

This paper described a method for analyzing the structural performance of a metal container used for disposing radioactive waste generated during the decommissioning of a nuclear power plant, and numerical analysis results of a method for reinforcing the container. The containers to be analyzed were those that can be used in near-surface and landfill disposal facilities scheduled to be operated at the Gyeongju radioactive waste disposal facility. Structural reinforcement of the container was performed by lattice reinforcement, column reinforcement, and bottom plate reinforcement. Accordingly, a total of 14 reinforcement cases were modeled. The external force causing damage to the container was set equivalent to the impact of a 9-m fall, accounting for the height of the vault at the near-surface disposal facility. The reinforcement methods with a high contribution to the structural performance of the container were concluded to be lattice and column reinforcements.

• Journal of Astronomy and Space Sciences
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• 제40권3호
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• pp.93-100
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• 2023

A study of uncertainty analysis was conducted on four key thermophysical properties of molten Platinum using a noncontacting levitation technique. More specifically, this work demonstrates a detailed reporting of the uncertainties associated with the density, volumetric thermal expansion coefficient, surface tension and viscosity measurements at higher temperatures for a widely used refractory metal, Platinum using electrostatic levitation (ESL). The microgravity experiments were conducted using JAXA's Electrostatic Levitation Furnace (ELF) facility on the International Space Station and the terrestrial experiments were conducted using NASA's Marshal Space Flight Center's ESL facility. The performance of these two facilities were then quantified based on the measurement precision and accuracy using the metrological International Standards Organization's Guide to the Expression of Uncertainty Measurement (GUM) principles.

• 방사선산업학회지
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• 제17권4호
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• pp.359-367
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• 2023

In this study, the function and purpose of the disposal cover, which is an engineering barrier installed to isolate the disposal vault of the near-surface disposal facility for radioactive waste from natural/man-made intrusion, and the design details of the demonstration facility for performance verification were described. The Demonstration facility was designed in a partially divided form to secure the efficiency of measurement while being the same as the actual size of the surface disposal facility to be built in the Intermediate & low-level radioactive waste disposal site of the Korea Radioactive Waste Agency (KORAD). The instruments used for measurement consist of a multi-point thermometer, FDR (Frequency Domain Reflectometry) sensor, inclinometer, acoustic sensor, flow meter, and meteorological observer. It is used as input data for the monitoring system. The 3D monitoring system was composed of 5 layers using the e-government standard framework, and was developed based on 4 components: screen, control module, service module, and DBIO(DataBase Input Output) module, and connected them to system operation. The monitoring system can provide real-time information on physical changes in the demonstration facility through the collection, analysis, storage, and visualization processes.

• Nuclear Engineering and Technology
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• 제38권2호
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• pp.185-194
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• 2006

Transient operations for an integral type reactor, SMART-P, have been experimentally investigated using a thermal-hydraulic integral test facility, VISTA (Experimental Verification by Integral Simulation of Transients and Accidents), in order to verify the system design and performance of the SMART-P, a pilot plant of SMART. The VISTA facility was subjected to various accident conditions such as feedwater increase and decrease, loss of coolant flow, and control rod withdrawal accidents in order to elucidate the thermal-hydraulic responses following such accidents and finally to verify the system design of the SMARTP. Full functional control logics have been implemented in the VISTA facility in order to control the required control action for an accident simulation. As one of the sensitivity tests to verify the PRHRS performance, the effects of the initial water level in the compensation tank are experimentally investigated. When the initial water level is 16%, the water is quickly drained and nitrogen gas is then introduced into the PRHR system, resulting in deterioration of the PRHRS performance. It is thus found that nitrogen ingression should be prevented to ensure stable PRHRS operation.

• 한국추진공학회지
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• 제12권1호
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• pp.37-43
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• 2008

우주발사체의 상단 추진기관은 고고도 환경에서 작동하므로 지상에서 그 성능을 최종적으로 검증하기 위해서는 고공환경을 모사할 수 있는 지상연소 시험설비가 필요하다. 원통형 초음속 디퓨저를 사용하면 배기가스의 모멘텀 만으로 비교적 간단하게 추진기관 주변에 고고도 환경의 낮은 주변 압력을 조성할 수 있다. 본 논문에서는 KSLV-I의 상단에 사용되는 킥모터의 고고도 시험을 위해 항공우주연구원이 구축한 고공환경모사 시험설비의 구성 및 규격에 대해 소개하고 있다. 5회의 연소시험을 통해 구축된 시험설비의 성능을 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2113-2115
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• 2000

It is necessary to install the arc generation facility in order to obtain the important technology for the design of breakers and switches, and for the improvement of their performance and reliability. With this facility, it is possible, to study the characteristics of Arc in air/gas/vacuum insulation environment. The facility briefly consists of capacitor bank which can charge enormous energy, an air-core reactor, experimental arc-chamber, and several measurement equipments. This facility can simulates the arc phenomena in breakers and switches by means of generating high currents. In order to study the arc phenomena in SF6 gas and vacuum and to test the quenching performance of the extinguishing chambers which are developing. we made experimental $SF_6$gas/vacuum chambers and measured several parameter's of chambers. And besides we visualized arc ignition and arc movement by means of high speed camera.

• 한국실내디자인학회논문집
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• 제16권4호
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• pp.72-80
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• 2007

Due to the recent Law on facilities Improvement in public performance facilities, equal access to the need of cultural satisfaction and the standards of facilities for people with disabilities are to be assessed. The aim of this study was to determine how to improve the facilities for disabled individuals and provide complementary guidelines for amenities designed for people with disabilities based on a comparative analysis of the disability codes in Korea, Japan, USA, Australia and Canada as well as a field observation. The results suggest the need for improved guidelines in terms of accessibility and accessible seating, which are summarized as follows: (1) The facility standards need to be complemented and clarified in terms of a detailed description, (2) regarding facilities for accessible seating, fall prevention handrails should be lowered to a height within the range of vision of the individual (3) The purpose and user's manual for theater and cultural facilities as well as detailed dimensional requirements need to be restated, and (4) an improvement in accessible seating in theaters and cultural facilities is needed. The purpose of the this study is to show an arrangement of a fundamental judgement and a ground data which can be complemented in planning a public performance facilities for the people with disabilities.

• 한국재난정보학회 논문집
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• 제17권1호
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• pp.39-52
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• 2021

연구목적: 최근 시설물 점검 및 진단에 있어 활용되는 첨단장비들이 증가하여 첨단장비의 검·인증제도의 필요성이 대두되고 있다. 본 연구는 시설물 점검 및 진단에 활용되는 터널스캐너의 성능검증 방법론을 제시하는 것을 목적으로 한다. 연구방법: 시설물 점검 및 진단에 활용되는 첨단장비의 성능검증 사례를 조사하고 전문가 자문회의를 통해 터널스캐너 성능검증 방법론을 제시하였다. 연구결과: 본 연구에서 제안하는 터널스캐너 성능검증 방법론은 1차 평가와 2차 평가로 구성된다. 1차 평가지표는 최소요구성능을 기준으로 구성되고, 2차 평가지표는 터널스캐너의 품질에 관여된 지표들로 구성된다. 결론: 본 연구에서 제시한 터널스캐너의 성능검증 방법론은 장비 사용자에게 공인된 성능 카탈로그를 제공할 수 있으며, 장비 개발자는 장비의 공인된 검증을 받을 수 있어 부실한 유지관리를 예방할 수 있을 것으로 기대된다.