• 동력기계공학회지
• /
• 제8권2호
• /
• pp.5-11
• /
• 2004

The failure frequency of the Emergency Diesel Generator(EDG) at Nuclear Power Plants(NPPs) is not so much lower than that of the Marine engines, whereas the running hours of the diesel engine at NPPs is much less than those of the engines for commercial service. The primary factor results from the severe surveillance test requirements such as fast start, large number of starting test, fast load-run, high load running, etc. The other factor comes from the excessive maintenance based on the engine maker's instruction manual that did not incorporate the peculiar characteristics of the diesel engines at NPPs. In this paper, the present preventive maintenance program on the basis of the Pielstick diesel engines was reviewed for the purpose of securing the reliability of the emergency diesel generator at NPPs and the ways for its improvement were presented by referring to the overseas cases for their applications.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권9호
• /
• pp.2302-2322
• /
• 2012

Wireless Body Area Networks (WBANs) are introduced as an enabling technology in tele-health for patient monitoring. Designing an efficient Medium Access Control (MAC) protocol is the main challenge in WBANs because of their various applications and strict requirements such as low level of energy consumption, low transmission delay, the wide range of data rates and prioritizing emergency data. In this paper, we propose a new MAC protocol to provide different requirements of WBANs targeted for medical applications. The proposed MAC provides an efficient emergency response mechanism by considering the correlation between medical signals. It also reduces the power consumption of nodes by minimizing contention access, reducing the probability of the collision and using an efficient synchronization algorithm. In addition, the proposed MAC protocol increases the data rate of the nodes by allocating the resources according to the condition of the network. Analytical and simulation results show that the proposed MAC protocol outperforms IEEE 802.15.4 MAC protocol in terms of power consumption level as well as the average response delay. Also, the comparison results of the proposed MAC with IEEE 802.15.6 MAC protocol show a tradeoff between average response delay and medical data rate.

• Nuclear Engineering and Technology
• /
• 제51권5호
• /
• pp.1470-1476
• /
• 2019

The nuclear power plants in South Korea have been designed in accordance with the U.S. Regulatory Guide 1.60 (R.G 1.60) design spectrum of which the peak frequency range is 2-10 Hz. The characteristics of the earthquakes at the Korea nuclear power plant sites were observed to be closer to that of Central and Eastern United States (CEUS) than the R.G 1.60, which is a lower amplification in a low frequency range, and a higher amplification in a high frequency range. The possibility of failure for sensitive power plant components in the high frequency range has been considered and evaluated. In this study, in order to improve the reliability of nuclear plant and administrative control procedures, seismic tests of an emergency diesel generator (EDG) were conducted using a shaking table under both high and low frequency ranges. From the tests, oil/lubricant leaks from the bolt connections, the fuel filter and the fuel inlet were observed. Therefore, the check list of nuclear plant components after an earthquake should include bolt connections of EDG as well as anchor bolts.

• 조명전기설비학회논문지
• /
• 제22권5호
• /
• pp.53-57
• /
• 2008

일반적으로 비상시 전원으로 디젤발전기를 가장 많이 사용하고 있으며, 하이브리드 전원소스(상용전원, 축전지, 연료전지, 태양전지 등)를 사용하여 부하에 안정적인 전력을 공급하기 위한 방법들이 연구되어지고 있다. 최근 비상시 전원으로 가장 많이 사용하고 있는 디젤발전기의 역할이 아주 중요하게 여겨지며, 운영부하에 따라서도 유연하게 동작되어야 하고, 신뢰성도 확보되어야 한다. 따라서 본 연구에서 부하 변동에 따른 최대전력 추종제어 기능이 가능하고, 고조파 억제 기능 및 안정주파수 유지기능이 가능하도록 부하 변동에 따른 디젤발전기의 제어기에 대하여 논하고자 한다.

• 방사성폐기물학회지
• /
• 제3권4호
• /
• pp.359-372
• /
• 2005

원자력발전소 사고시 방사성물질이 발전소외 지역으로 유출될 경우 주민을 안전하게 보호하기 위한 조치의 일환으로 주민소개가 고려된다. 소개시간 산정에 필요한 인자를 도출하고, 각각의 인자에 대해 원전 주변의 현장자료를 토대로 부지주변의 교통환경 여건을 반영하여 울진원전의 방사선비상계획구역 내의 주민전체를 소개시키는데 소요되는 시간을 예측하였다. 평상교통, 여름철 첨두교통, 그리고 겨울철 첨두교통에 대해 각각 주간 및 야간, 평상기상 및 악기상의 경우로 나누어 12가지의 주민소개 시나리오를 설정하였다. 비상계획구역 경계 남단과 북단에서 모든 소개차량(인구)이 비상계획구역을 벗어나는 데 걸리는 시간은 전체적으로는 $210\~315$분 정도로 예측되었다. 소개시간은 밤이 낮보다 약 45분 정도 더 소요되는 것으로 예측되었다.

• 전력전자학회논문지
• /
• 제20권1호
• /
• pp.11-18
• /
• 2015

This paper proposes a high-efficiency 3-kW hybrid ESS with emergency power supply. The proposed system enables efficient use of power from photovoltaic (PV) cells and energy storage system (ESS). The proposed system can operate as an uninterruptible power supply (UPS) when grid fault occurs, providing seamless transfer from grid-connected mode to stand-alone mode. The LLC converter for PV achieves ZVS turn-on of switches and ZCS turn-off of diodes, and the isolated bidirectional DC-DC converter for ESS achieves ZCS turn-off regardless of load condition, resulting in high efficiency. The efficiency and performance of the proposed hybrid ESS has been verified by a 3-kW prototype.

• 한국응급구조학회지
• /
• 제15권2호
• /
• pp.27-42
• /
• 2011

Purpose: This study intended to improve quality of prehospital emergency care for trauma patients by figuring out its current situations and problems based on run-sheets and questionnaires of 119 emergency medical technicians (EMTs). Methods: This study conducted a research of 425 trauma patients transferred to the 3rd hospital in G-city by 119 ambulances from July 1, 2008 to June 30, 2009. We aslo utilized 114 copies with questionnaires of 119 EMTs working in J-province. The data were analyzed with SPSS 18.0. Results: There were 425 trauma patients including 272 men and 137 patients with traffic accident. When it comes to types of 119 EMTs who delivered cares to patients, there were 206 (48.5%) advanced EMTs, 101 (23.8%) basic EMTs, 50 (11.8%) nurses and 43 (10.2%) rescue education receivers. The most frequent measured vital sign was pulse rate (54.1%). Regarding assessment of systolic blood pressure, pulse rate and respiration rate, there were some significant differences in accordance with type of 119 EMTs. Among the 317 patients evaluated 'emergency' in field, 137 patients returned to their home. Prehospital emergency cares accounted for 861, around 2.0 treatments per a patient. In view of questionnaire, the 74.6% of 119 EMTs hoped supplement of man power for proper prehospital care to trauma patients. Conclusion: This study suggested that it is necessary to develop detailed guidelines for trauma patients so as to improve quality of trauma patient evaluation and prehospital care. Furthermore, improvement of emergency care systems will reduce mortality of trauma patients and lead to their good outcome.

• 전자공학회논문지
• /
• 제51권3호
• /
• pp.10-21
• /
• 2014

후쿠시마 원전사고는 자연재해에 의한 중대사고 발생 시 전원공급 중단 및 극한 환경으로 인해 발전소 내부 상황을 정확하게 파악하지 못하였고, 대부분의 계측제어시스템이 그 기능을 제대로 발휘하지 못해 비상냉각기능이 상실되어 수소폭발 및 다량의 방사능이 누출된 사고였다. 본 논문에서는 중대사고 발생 시에도 발전소 내부 상황을 감시하고, 적절히 제어할 수 있는 비상대응시스템에 대하여 소개하고, 비상대응시스템에 사용되는 무선통신망의 성능요구사항에 대해서 논의하고, 요구사항을 만족시킬 수 있는 비상통신망의 성능을 마코프 모델을 이용하여 분석하였다.

• 한국주거학회논문집
• /
• 제27권4호
• /
• pp.59-66
• /
• 2016

The purpose of this study is to examine the necessity of 'emergency plumbing equipment for preventing the spread of water leakage'. It reviews social and economic costs when there is spread of water leakage and finds out that those are enormous. Expansion of water leakage causes conflicts between neighbors, economic loss and inconvenience from damages on facilities like elevator and power failure. Next, it examines the inability of existing plumbing equipment when it comes to spread of water leakage. Newly defined 'Surface Leakage' means rapid leak in the surface, and 'Internal Leakage' means seeping out slowly and gradually buried in the pipeline. It will also be analyzed by separating the concept of a leak in the two concepts of a 'Surface Leakage' and 'Internal Leakage'. It proposes emergency plumbing equipment for preventing the spread of water leakage as a solution for the expansion of water leakage. It explains general concepts of emergency plumbing equipment for preventing the spread of water leakage. It will also examine the effectiveness of the user by performing a survey of 420 multi-level building their opinion on the effects of an emergency plumbing equipments to prevent the spread of water leakage.

• 기본간호학회지
• /
• 제25권3호
• /
• pp.210-219
• /
• 2018

Purpose: The purpose of this study was to investigate the effects of emergency setting visitors' knowledge and behavior patterns in relation to prevention of respiratory tract infections. Methods: A descriptive survey was used. The participants were visitors to the emergency service in 'D' general hospital in 'D' city, and the data were collected from July 1 to September 1, 2016. The collected data were analyzed using frequency analysis, t-test, ANOVA, $Scheff{\acute{e}}$ test, Pearson correlation coefficients, and multiple regression analysis. Results: Factors influencing prevention of respiratory tract infections were visitors' education level, methods of dissemination of prevention information, and participants' knowledge with regard to preventive methods. The explanatory power was found to be 35% in the regression model. Conclusion: The findings indicate that visitors' education level, knowledge of infection prevention, and the dissemination of information regarding infection prevention by the hospital play an important role in the prevention of respiratory tract infections in emergency services in the hospital. These results highlight the need for a customized education program for prevention of respiratory tract infections in emergency settings. Programs should take into consideration the educational background of visitors, and provide them with appropriate information regarding infection prevention.