• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2603-2605
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• 2003

증기발생기(SG : Steam Generator)는 다수의 세관으로 구성되어 원자로에서 발생한 열을 이용하여 발전기 터빈을 구동시키는 원동력인 증기를 생성해 주는 기능을 하는 원자력발전소의 핵심 설비이다. 증기 발생기 세관의 건전성을 확보하기 위해 매주기 계획예방 정비, 즉 가동중검사마다 정기적인 와전류검사를 수행하고, 검사결과에 따라 전열관 보수 등과 같은 제반 조치를 취하고 있다. 현재 검사데이터 DB 구축은 일부 발전소에 개발되어 운영중에 있고, 세관 DB와는 별도로 통계정보만을 관리하는 증기발생기 성능관리시스템이 운영되고 있으며, 또한 각 발전소마다 수질을 계측하여 수화학 성분을 감시하는 수질관리시스템이 운용되고 있다. 이러한 이원화된 DB 및 시스템을 통합하고 연계하여 전 원전의 증기발생기를 종합적으로 관리 할 수 있는 시스템의 필요성이 대두되었다. 따라서 본 논문에서는 현장에 보관되어 있는 모든 세관 검사데이터를 취득하여 대용량 데이터베이스를 설계 및 구축하고 이기종의 분산된 수질관리시스템 DB를 연계하여, 증기발생기의 설계/제작부터 검사결과 Mapping, 추이 분석을 통한 수명평가에 이르는 전 과정을 통합 관리한 수 있는 시스템을 개발하고 그 구현방안을 제시한다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.557-558
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• 2007

변화, 발전하는 IT기술과 디지털 기술, 그리고 네트워킹 기술 등에 따라 변전소의 운용 및 자동화 부문에 있어서도 적지 않은 변화가 일어나고 있다. 변전소의 건설 및 운용 면에 있어서도 예외가 아니며, 관련된 관심 사항으로는 시스템 구축 및 운용 시의 경제적인 측면, 시스템의 신뢰성, 그리고 유지보수 및 설비 관리의 효율성 등을 언급할 수 있다. 최근의 기술 추세는 Ethernet 통신 기반의 Network Device를 근간으로 하는 시스템으로의 변신을 주장하고 있으며, 세계 유수의 전력 설비 Maker에서도 이에 부응하기 위한 Network Device를 개발, 출시하고 있는 실정이다. 당소에서도 이와 같은 기술 추세에 부응하여 소위 미래형 변전소에서 요구되는 각종 ND의 개발을 추진하고 있으며, 그 첫번째 결과물로 154kV GIS의 운용 시에 요구되는 각종 제어 및 감시를 위한 Digital Control Unit(이하 DCU)을 개발하였다. 두 번째로 이와 같은 DCU와 연계하여 기존의 Remote Control 기능을 구비하고 상위시스템과 연결되며 변전실내에서 운용되는 Remote Control Unit(이하 RCU)을 개발하였다. 마지막으로 예방진단 시스템과 관련하여 주요 전력 설비의 상태 정보를 취합하는 Serial 통신 기반의 Static Type의 Diagnostic Analysis Unit(이하 DAU)을 하나의 Network Device로 개발함으로써 감시, 진단, 제어 등의 요구기능이 일체화 된 네트워크 기반의 미래형 변전소 자동화 시스템 구축에 한걸음 다가가는 기반을 마련하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.401-401
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• 2019

상수관망시스템은 정수처리 된 용수를 수요처에 공급하는 사회기반시설물이며, 주로 지하에 매설되는 시설물의 특성상 관로에 누수가 발생하였을 경우, 정확한 발생지점을 파악하기가 어렵다. 특히, 지진에 의해 시스템 내 다중지점에 누수가 발생할 경우, 장기간 경제적 손실과 사용자의 불편이 예상되므로 신속히 누수지점을 파악한 후, 피해 관로의 적절한 교체 혹은 보수가 이루어져야 한다. 본 연구에서는 지진으로 인해 상수관망에 발생한 다중 누수관로의 정확한 탐지를 위해 다양한 누수탐지 기법을 제안하고 모의결과를 비교, 분석하였다. 가상의 다중 누수 시나리오를 모의한 후, 시스템 내 설치된 수압계와 유량계의 누수발생 전, 후 모니터링 값을 이용하여 1) 최적화 알고리즘을 이용한 Calibration 기법, 2) 수리해석을 통한 누수지점 역추적 기법, 3) 인공신경망을 이용한 Pattern 학습법 등을 적용하였다. 동일한 다중 누수 시나리오를 각 누수탐지 기법에 적용함으로써 누수지점 산정 결과에 대한 정확도를 비교, 분석하였다. 본 연구는 최근 국내에서 발생빈도가 높아지고 있는 지진재해 발생에 대비하여 상수관망시스템의 지진피해 복구 연구를 위해 활용될 수 있을 것으로 기대한다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.183-192
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• 2022

Function and performance degradation in tunnel structure can cause road's function loss, proactive maintenance is needed to prevent the initial damage from progressing to intensified damage. Inspection and diagnosis are implemented in accordance with regulations, but it does not fully reflect maintenance processes such as inspection and diagnosis, planning rehabilitation and carrying out. It was carried out for 5,540 cases inspection and diagnosis result in 1,728 tunnels was analyzed to suggest rational maintenance plan in this study.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.322-331
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• 2017

District heating was first introduced in Korea in 1985. As the service life of the underground thermal piping network has increased for more than 30 years, the maintenance of the underground thermal pipe has become an important issue. A variety of complex technologies are required for periodic inspection and operation management for the maintenance of the aged thermal piping network. Especially, it is required to develop a model that can be used for decision making in order to derive optimal maintenance and replacement point from the economic viewpoint in the field. In this study, the analysis was carried out based on the repair history and accident data at the operation of the thermal pipe network of five districts in the Korea District Heating Corporation. A failure probability model was developed by introducing statistical techniques of qualitative analysis and binomial logistic regression analysis. As a result of qualitative analysis of maintenance history and accident data, the most important cause of pipeline damage was construction erosion, corrosion of pipe and bad material accounted for about 82%. In the statistical model analysis, by setting the separation point of the classification to 0.25, the accuracy of the thermal pipe breakage and non-breakage classification improved to 73.5%. In order to establish the failure probability model, the fitness of the model was verified through the Hosmer and Lemeshow test, the independent test of the independent variables, and the Chi-Square test of the model. According to the results of analysis of the risk of thermal pipe network damage, the highest probability of failure was analyzed as the thermal pipeline constructed by the F construction company in the reducer pipe of less than 250mm, which is more than 10 years on the Seoul area motorway in winter. The results of this study can be used to prioritize maintenance, preventive inspection, and replacement of thermal piping systems. In addition, it will be possible to reduce the frequency of thermal pipeline damage and to use it more aggressively to manage thermal piping network by establishing and coping with accident prevention plan in advance such as inspection and maintenance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.145-152
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• 2009

Domestic Kori-1 MCR was partially modified in 2007 and will be renovated entirely in 2013. Digital devices partially replacing original analog devices have been introduced and standard alone computer systems such as SPDS have been integrated into the plant computer. Upgrading KSNP's MCR based on the ditalization is planned for 2015. However, the site engineers and operators are reluctant to the advanced systems. Therefore, a prototype for the KSNP's advanced MCR has been developed to increase the acceptance level of the operators and field engineers and also, to evaluate user interfaces and I&C architecture. For enhancing support of the operators' work, a P&ID based display system composed of multi-layers, which are linked through a context sensitive menu each other, has been adopted. The $1^{st}$ layer displays a simplified P&ID, the $2^{nd}$ layer control related diagrams such as controllers and logic diagrams, the $3^{rd}$ layer trends, etc. The end point view of MCR for KSNP is also suggested considering reliability and operability of the digital systems. Additionally, modernization strategies over the overhaul periods, that do not have much impact on operation and configuration efforts are suggested.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.409-417
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• 2019

Purpose: Since the implementation of the Chemical Substance Management Act, data on the number of occurrences by annual chemical accident in Korea and the contractor's contract data received from the competent authority were used. After the implementation of the contract reporting system, the contribution to the reduction of chemical accidents is summarized by statistical data. The characteristics of each region, month, type and those of similar industries and human life were compared and analyzed. Method: 4 years of chemical accident statistics from 2015 to 2018 and since 2003, we have used data from the Chemical Safety Clearing-House (CSC), which provides safety information on cases of chemical accidents. Results and Conclusion: The risk of accidents increases as a number of unskilled workers are put into the workplace during the period when the hazardous chemical handling process is temporarily suspended. Through the reporting for awarding a contract, the operators are strengthening the safety management of chemical accidents by educating unskilled workers and wearing personal protective equipment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.711-717
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• 2017

The railway is a public transportation system that provides large-scale passenger transportation and service, whose reliability and safety is the top priority. The wiring of railway vehicles is classified into train control lines (train lines) and communication lines. The train lines are used for input / output signals related to vehicle driving and safety functions, and the communication lines are used for the input / output signals for passenger services such as broadcasting. In order to measure the reliability of railway vehicles, a train line is applied to the input / output interface of the control signals between the electric control devices in the vehicle, and there are many electromechanical devices such as relays and contactors for the control logic. In fact, since the vehicle control circuit is composed of several thousand contacts, it is difficult to check for errors such as contact failure, and it is impossible to check the real-time status, so a lot of manpower and time is required for regular maintenance. Therefore, we analyze the current state of the train line design of the electric equipment used for driving and services in domestic railway cars and propose three wiring reduction methods to improve it. Based on the analysis of domestic electric vehicles, it was confirmed that the wiring reduction effect is 35% or more.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.453-460
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• 2017

This study proposes effective quality control and maintenance method by developing a new qualitative evaluation method of apron for medical radiation protection. As an experimental material, one of 0.45 mm lead and 100 of 0.45 mm Pb aprons were used and irradiated under the conditions of a tube voltage of 75 kVp and a tube current of 12.5 mAs to obtain an image. and using the Image J program, PSNR values were compared and analyzed. The results showed that there were 40 aprons (less than 11dB), 55 aprons (less than 11dB, less than 30dB), and 5 aprons (30dB or more). In addition, the dose showed a normal distribution for the apron, and 5 aprons with PSNR less than 11dB and 30dB or more were selected and divided into 8 zones, and these groups were statistically significant.

• Food Science of Animal Resources
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• v.23 no.2
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• pp.115-121
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• 2003

The pork quality was determined with following treatments. The meat samples were obtained from pigs which had been fed finishing pig diets containing 5% beef tallow(Control), 3% beef tallow and 2% perillar seed oil(T1), 250 ppm vitamin E(a-tocopheryl acetate) in T1(T2), 3% beef tallow and 2% squid viscera oil(T3), 250 ppm vitamin E in T3(T4), 3% beef tallow and 2% CLA(Conjugated linoleic acid, T5). T1 had the lowest sarcomere length, salt solubility and total protein contents among the treatments. Salt solubility and total protein content of T2 and T4 which had been fed diets containing Vit. E were higher than those of T1 and T3 which had not been fed diets without Vit. E. pH and water holding capacity(WHC) values of control were higher than those of T1, T3 and T5, while WHC of T2 and T4 was higher than those of T1, T3 and T5. The hunter L value of meat and a value of fat showed higher in T5 than those in control, T, T3. The adhesiveness of T3 and the springiness of T5 in cooked meat showed higher level than other treatments.