• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.36 no.6
• /
• pp.598-602
• /
• 2023

With the purpose of instilling an awareness of the safety of users of electrical equipment and inducing voluntary facility improvement through the safety rating system for general low voltage electrical equipment, simulation and field application of the safety rating of general low voltage electrical equipment were conducted. For the introduction and application of the safety rating system for general low-voltage electrical equipment, data related to domestic safety was investigated and analyzed, cases of introduction in other fields were reviewed, and for design, the 4M risk assessment method of the Korea Occupational Safety and Health Agency and the cases of safety index development in Korea were analyzed and standardized. Safety rating system simulations were conducted for general low-voltage electrical equipment, and problem improvement measures were prepared by analyzing the results through on-site verification and simulation applied to the initial design. Design standards for the introduction of the safety rating system for general low-voltage electrical equipment were prepared, and 394 youth training facilities were applied to the field to see if the design standards were practically applicable to the field. With the application of the safety rating system for low-voltage electrical equipment for general use, youth training facilities that had been classified as 'appropriate' were able to induce an upgrade to a higher level through voluntary facility improvement according to the application of grades (A to E). As a result of inducing voluntary repair projects based on the results of the 1st and 2nd inspection of youth training facilities, it was confirmed that 86 facilities received grade A, 225 facilities received grade B, and only 311 facilities received grade A to B out of a total of 394 facilities, and there was no grade E.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.19 no.4
• /
• pp.693-700
• /
• 2024

This study aims to analyze the concept and application of AI-based predictive maintenance in the railroad industry and draw implications from it. Focusing on the adoption of AI-based maintenance systems by the Korea Railroad Corporation and Seoul Metro, we examined how AI technology can improve the efficiency and safety of railroad operations. We also compared and analyzed the application of AI technology in the European railroad industry through the cases of Deutsche Bahn in Germany and SNCF in France. The study found that AI-powered predictive maintenance contributes to reducing the frequency of breakdowns, reducing maintenance costs, and increasing the reliability of railroad operations.

• Geophysics and Geophysical Exploration
• /
• v.25 no.3
• /
• pp.120-128
• /
• 2022

There are 17,000 reservoir dams in Korea, of which more than 85% were built over 50 years ago. Old embankment dams are weakened by internal erosion and suffusion phenomena due to preferential leakage paths and this ongoing weakening can cause their failure. Therefore, early warning associated with leakage in an embankment dam is crucial to prevent its failure. An electrical resistivity survey is a non-destructive, real-time and in-situ technique for detecting the development of leakage zones and general conditions of embankment dams. Because of its advantages, the electrical resistivity survey is widely used for reservoir safety inspections. However, the electrical resistivity survey is still not officially included in the precise safety inspection of reservoir dams because it cannot present a quantitative index of dam safety. In this study, we propose a method for calculating the leak index according to the water content evaluated from the electrical resistivity survey and/or induced polarization survey. Particularly, by proposing a quantitative leak index calculation method from monitoring surveys and independent surveys, we provide a theoretical basis for including electrical resistivity and induced polarization surveys as components of the precise safety inspection of reservoirs dams.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.6
• /
• pp.599-609
• /
• 2021

A novel grounding system, which is presented in IEC 60364, has been adopted since 2021. A safety evaluation for the human body on the grounding system is required due to the various characteristics of the touch voltage and current passing when the human body experiences an electric shock. The Korea Electrical Safety Corporation (KESCO) and Korea Electric Association (KEA) have been conducting a safety technical education on the grounding system. On the other hand, it is difficult to instruct the electrical safety manager because of a lack of safety evaluations for the test equipment on the grounding system. Therefore, this paper modeled and implemented a test device for a safety evaluation depending on the grounding system of IEC 60364. Namely, this paper presents the modeling of the test device for a safety evaluation using PSCAD/EMTDC S/W, which is composed of an AC grid section, s test device section on the grounding system, and a sub-device section. This paper implemented a test device for safety evaluation, which consisted of an AC grid section, TT grounding system section, TN-S grounding system section, and monitoring section. From the simulation and test results with the safety characteristics of the human body in the TT and TN-S grounding system, when the fault impedances are 0[Ω], 10[Ω], and 100[Ω], the currents passing through the human body in the TT grounding system are 104[mA], 87.4[mA], and 35.5[mA], respectively. The corresponding currents in the TN-S grounding system are 54.9[mA], 4.1[mA], and 0.4[mA], respectively. Based on the results, the protection performance for an electric shock to the human body in the TN-S system is better than the TT system. This can be improved when the existing grounding system is changed from the TT system to the TN-S system.

• Geophysics and Geophysical Exploration
• /
• v.22 no.3
• /
• pp.99-106
• /
• 2019

Resistivity method has been used for the dam safety inspection and, for the convenience of fieldwork, two-dimensional (2D) resistivity data has been usually measured along the dam crest. However, since the dam has three-dimensional (3D) structure, 2D resistivity survey along the dam crest violates 2D assumption and 3D effects caused by 3D topography and material properties in the dam distort the inversion result of 2D resistivity data acquired along the dam crest. Furthermore, it is really hard to evaluate the 3D structure of the dam and 3D leakage pathway using 2D resistivity survey because 2D resistivity survey can provide only 2D resistivity section beneath the survey line. In this study, 3D resistivity survey was conducted at a dam in Korea. By comparing the results from 3D and 2D resistivity surveys, merit and demerits of 3D survey were investigated. Finally, it was confirmed that 3D survey can provide more accurate information about the dam status and 3D leakage pathway compared to the 2D survey. Therefore the 3D resistivity survey should be actively expanded for more accurate dam safety inspection even though more time and expense are required.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.10
• /
• pp.166-175
• /
• 2007

Nowadays, the power quality issue becomes very important in the electric distribution system. Especially, when a distribution transformer is replaced, the customers who are supplied electricity from the transformer feel inconvenience due to electric outage. Therefore, an advanced method for the distribution transformer replacement without outage is strongly required. The conventional method is the primary-secondary high voltage bypass method according to the transformer utilization factor and the field condition. But it is inconvenient and has some problems such as breakdown and security troubles of the workers according to the unauthorized and temporary work. Therefore, the new scheme for the replacement with uninterruptable power supply is demanded. This paper proposes the new replacement method using the phase converter. The proposed method can reduces the process of replacement work and also ensures worker's safety. Therefore, the method is reasonable in comparison with the conventional method. The proposed method is able to contribute the national economy growth and elevate the convenience of national life by uninterruptable power supply.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.8 no.4
• /
• pp.87-90
• /
• 2008

This research is to study and analyze our country's management of disasters, the present condition of cultural heritages bases on the examples of temples, and Japan's safety management prevention of buddhist temple. As a result, this research aims to how to improve the temple fire prevention system. To improve the anti-fire system of temples, it is important to make new laws about fire lose to minimize cultural property lose. Secondly, to protect self-contained type fire alarm device, with aerosol type hand propelled fire extinguishers to prevent fire lose. Lastly, construction work of electric engineer is necessary to prevent temple fire loses.

• The Journal of the Acoustical Society of Korea
• /
• v.26 no.4
• /
• pp.166-172
• /
• 2007

In this paper, we address the target positioning performance of Multi-Static sonar with respect to target positioning method and measurement error. Based on the analysis on two candidate solution approaches, namely, Least Square (LS) using range and angular information simultaneously and Maximum Likelihood (ML) using only range information as the existing information fusion methods for possible application to Multi-Static sonar, we propose to employ ML using range and angular information. Assuming that each sensor can receive range and angular information, we conduct representative comparison experiments over the existing and proposed methods under various measurement noise scenarios. We also investigate the target positioning performance according to number of sensors, distance between transmitter and receiver. According to the experimental results, RMSE of the proposed ML with distance and direction information is found to be more superior to ML using distance alone and to LS in case distance between transmitter and receiver is longer and number of receiver is smaller.

• Journal of the Korean Institute of Gas
• /
• v.5 no.4 s.16
• /
• pp.21-26
• /
• 2001

Because of the continuous growth of energy consumption, and also tile tendency to site power lines and pipelines along the same routes, the close proximity of high voltage structures and metallic pipelines has become more and more frequent. Recently, the results of assessment about a system integrity are needed in korea also when a gas pipeline is running parallel with high voltage power line in same submarine tunnel, Therefore, we analyze the system integrity(AC corrosion of pipe, melting of pipeline coating, safety of insulation flange, especially cathodic protection system which are rectifier and CI(cathodic Isolator)) resulting from the influence of high voltage power system.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.652-654
• /
• 2007

본 논문에서는 국가의 기간 에너지원인 전력망을 구성하는 구조물인 송전철탑의 설계하중에 가장 큰 요인으로 작용하는 기준풍속 산정을 위한 연구내용을 고찰하고자 한다. 현행의 송전용 지지물 설계 기준은 전기설비기술기준에 고시된 가공전선로 지지물에 관한 기준을 토대로 전력사의 실무적인 설계를 위하여 보다 구체화하여 작성된 한국전력공사 송전설계기준에 근거하고 있다. 이러한 기존 설계기준은 1985년 이전의 기상자료를 토대로 제정되어 본 논문에서는 1980년대 후반부터 약 20년간의 기상청의 풍향, 풍속자료를 추가로 확보하고 이를 분석하여 재현기간을 반영한 지역별 설계기준 풍속 Map을 제시하였다. 이러한 흐름으로 최근의 기상자료를 포함하여 보다 정확한 분석을 도모하고, 사회 환경의 급변함에 따라 우려되는 기상이변 등을 고려한 안전성과 경제성이 향상된 기준풍속 산정과정을 고찰하고, IEC 등 해외 주요국의 풍하중 설계기준에서 반영하고 있는 국부지형을 고려한 설계방법에 대한 국내 기준 적용성 평가를 위한 비교분석 결과를 소개하였다.