• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1603-1618
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• 2024

Emergency operation plans are indispensable elements for effective process safety management especially when unanticipated events occur under extreme situations. In the paper, a synthesis framework is proposed for the integration success path planning and performance analysis. Within the synthesis framework, success path planning is implemented through flow-directed signal tracing, renaming and reconstruction from a complete collection of Minimal Path Sets (MPSs) that are obtained using graph traversal search on GO-FLOW model diagram. The performance of success paths is then evaluated and prioritized according to the task complexity and probability calculation of MPSs for optimum action plans identification. Finally, an Auxiliary Feed Water System of Pressurized Water Reactor (PWR-AFWS) is taken as an example system to demonstrate the flow-directed MPSs search method for success path planning and performance analysis. It is concluded that the synthesis framework is capable of providing procedural guidance for emergency response and safety management with optimal success path planning under extreme situations.

• 한국응급구조학회지
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• 제28권2호
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• pp.7-19
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• 2024

Purpose: To adjust item numbers in a national test, this study used item response theory to examine changes in average scores, reliability, difficulty, and discrimination according to the adjustment of item numbers. Methods: We analyzed the dichotomous coding of correct and incorrect answers of 473 examinees in a mock test conducted in 2023. Additionally, as an explanatory pilot study, we used an online questionnaire to survey experts on their perceptions of the appropriate item numbers for each test subject from January 18, 2024, to February 15, 2024. Results: Regarding the item numbers on the national exam, experts preferred to reduce the number of management of emergency patients (33.14±6.09, p<.05) and advanced emergency medical care: subtopics (104.49±11.55, p<.05), and the total number of questions (217.82±20.95, p<.05). In a simulation set in which items with low item fit were removed after fitting a two-parameter item response theory model, reliability was maintained at .910 until the 5th test consisting of 185 questions with little loss of difficulty, discrimination, and average score, and there was no correlation between item numbers and average score. Conclusion: Experts responded that reducing the number of items on the national exam was appropriate. As a result of the item reduction simulation, there was no significant loss in the average score, difficulty, discrimination, or reliability. More reliable results could be obtained if the results were based on a validity analysis and analyzed using actual national exams.

• 한국안전학회지
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• 제18권2호
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• pp.104-118
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• 2003

It has been criticized that conventional human reliability analysis (HRA) methodologies for probabilistic safety assessment (PSA) have been focused on the quantification of human error probability (HEP) without detailed analysis of human cognitive processes such as situation assessment or decision-making which are crticial to successful response to emergency situations. This paper introduces a new human reliability analysis (HRA) methodology, AGAPE-ET (A guidance And Procedure for Human Error Analysis for Emergency Tasks), focused on the qualitative error analysis of emergency tasks from the viewpoint of the performance of human cognitive function. The AGAPE-ET method is based on the simplified cognitive model and a taxonomy of influencing factors. By each cognitive function, error causes or error-likely situations have been identified considering the characteristics of the performance of each cognitive function and influencing mechanism of PIFs on the cognitive function. Then, overall human error analysis process is designed considering the cognitive demand of the required task. The application to an emergency task shows that the proposed method is useful to identify task vulnerabilities associated with the performance of emergency tasks.

• 말소리와 음성과학
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• 제8권2호
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• pp.31-39
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• 2016

In emergency dispatching at 119 Command & Dispatch Center, some inconsistencies between the 'standard emergency aid system' and 'dispatch protocol,' which are both mandatory to follow, cause inefficiency in the dispatcher's performance. If an emergency dispatch system uses automatic speech recognition (ASR) to process the dispatcher's protocol speech during the case registration, it instantly extracts and provides the required information specified in the 'standard emergency aid system,' making the rescue command more efficient. For this purpose, we have developed a Korean large vocabulary continuous speech recognition system for 400,000 words to be used for the emergency dispatch system. The 400,000 words include vocabulary from news, SNS, blogs and emergency rescue domains. Acoustic model is constructed by using 1,300 hours of telephone call (8 kHz) speech, whereas language model is constructed by using 13 GB text corpus. From the transcribed corpus of 6,600 real telephone calls, call logs with emergency rescue command class and identified major symptom are extracted in connection with the rescue activity log and National Emergency Department Information System (NEDIS). ASR is applied to emergency dispatcher's repetition utterances about the patient information. Based on the Levenshtein distance between the ASR result and the template information, the emergency patient information is extracted. Experimental results show that 9.15% Word Error Rate of the speech recognition performance and 95.8% of emergency response detection performance are obtained for the emergency dispatch system.

• 한국산업융합학회 논문집
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• 제26권6_3호
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• pp.1341-1347
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• 2023

This study proposes to ensure the seismic stability of an existing switchboard for emergency diesel generator by applying mode analysis, static analysis and dynamic analysis. First, a three dimensional model for the swithboard was made with simplification for mode analysis. Next, The mode analysis for the finite element model of the existing switchboard was performed. The 1st natural frequency below 33 Hz, the seismic safety cutoff frequency, was calculated to be 21.943 Hz. Finally, based on the seismic stability theory, the von-Mises equivalent stresses derived by structural analysis and response spectrum analysis under the normal and faulted conditions were 74.179 MPa and 49.769 MPa, respectively. These are less than specified allowable stresses. So seismic stability was confirmed.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2534-2546
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• 2021

Nuclear emergency preparedness and response is an essential part to ensure the safety of nuclear power plant (NPP). Key support technologies of nuclear emergency decision-making usually consist of accident diagnosis, source term estimation, accident consequence assessment, and protective action recommendation. Source term estimation is almost the most difficult part among them. For example, bad communication, incomplete information, as well as complicated accident scenario make it hard to determine the reactor status and estimate the source term timely in the Fukushima accident. Subsequently, it leads to the hard decision on how to take appropriate emergency response actions. Hence, this paper aims to develop a method for rapid source term estimation to support nuclear emergency decision making in pressurized water reactor NPP. The method aims to make our knowledge on NPP provide better support nuclear emergency. Firstly, this paper studies how to build a Bayesian network model for the NPP based on professional knowledge and engineering knowledge. This paper presents a method transforming the PRA model (event trees and fault trees) into a corresponding Bayesian network model. To solve the problem that some physical phenomena which are modeled as pivotal events in level 2 PRA, cannot find sensors associated directly with their occurrence, a weighted assignment approach based on expert assessment is proposed in this paper. Secondly, the monitoring data of NPP are provided to the Bayesian network model, the real-time status of pivotal events and initiating events can be determined based on the junction tree algorithm. Thirdly, since PRA knowledge can link the accident sequences to the possible release categories, the proposed method is capable to find the most likely release category for the candidate accidents scenarios, namely the source term. The probabilities of possible accident sequences and the source term are calculated. Finally, the prototype software is checked against several sets of accident scenario data which are generated by the simulator of AP1000-NPP, including large loss of coolant accident, loss of main feedwater, main steam line break, and steam generator tube rupture. The results show that the proposed method for rapid source term estimation under nuclear emergency decision making is promising.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1979-1990
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• 2021

Evacuation Time Estimate (ETE) can provide decision-makers with a likelihood to implement evacuation of a population with radiation exposure risk by a nuclear power plant. Thus, the ETE is essential for developing an emergency response preparedness. However, studies on ETE have not been conducted adequately in Korea to date. In this study, different cohorts were selected based on assumptions. Existing local data were collected to construct a multi-model network by TSIS-CORSIM code. Furthermore, several links were aggregated to make simple calculations, and post-processing was conducted for dealing with the stochastic property of TSIS-CORSIM. The average speed of each cohort was calculated by the link aggregation and post-processing, and the evacuation time was estimated. As a result, the average cohort-based evacuation time was estimated as 2.4-6.8 h, and the average clearance time from ten simulations in 26 km was calculated as 27.3 h. Through this study, uncertainty factors to ETE results, such as classifying cohorts, degree of model complexity, traffic volume outside of the network, were identified. Various studies related to these factors will be needed to improve ETE's methodology and obtain the reliability of ETE results.

• 보건의료산업학회지
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• 제6권3호
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• pp.1-11
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• 2012

The purpose of this study is to identify the effects of emergency medical technicians' personal traits and job characteristics on job/social stress, job satisfaction, role conflicts, organizational commitment, and self-efficacy. The study population was emergency medical technicians who is working at the hospitals in Yeungnam province. The 200 questionnaires were administered by using ground mail, e-mail, and personal visits and 156 questionnaires were returned(82.5% response rate). Social stress, job satisfaction and role conflicts were significantly determined by personal traits and job characteristic variables. However, job stress, organizational commitment and self-efficacy was only significantly determined by job characteristic variables. In social stress and role conflicts, the subjects with challenge, sociability, acceptance and prudence traits were tend to be significantly higher scores compared to the stability traits. Additionally, among social stress regression models, adding job characteristics to the personal traits model, $R^2$ was increased up to 19% and adding personal traits to the job characteristics model, $R^2$ was increased up to 14%. In conclusion, the study found that personal traits and job characteristics are important variables in explaining social stress, job satisfaction and role conflicts, that would have important managerial implications for recruiting, hiring and managing either new or current emergency medical technicians efficiently.

• 한국정보과학회논문지:정보통신
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• 제28권4호
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• pp.489-497
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• 2001

차세대 정보전에서는 자신의 정보 시스템에 대한 침해방지, 복구 등의 수동적인 형태의 보호뿐만 아니라 상대방의 정보 기반구조(Information Infrastructure)에 대한 공격과 같은 적극적인 형태의 보호가 요구된다. 침입이 발생함과 동시에 시스템에 대한 피해를 최소화하고 침입자 추적 등의 즉각적인 대응을 하기 위해 정보보호시스템이 인간의 개입없이 자동적으로 대응하는 기능을 제공할 필요가 있다. 본 논문에서는 자기확장 모니터링 기법과 이를 기반으로 설계된 침입자동대응 모델을 제시한다. 또한 제안된 모델에 의해 설계, 구현된 침입자동대응 시스템인 ARTEMIS(Advanced Realtime Emergency Management Identification System)를 소개한다. 자기보호 기능을 가진 모니터링과 복제를 이용한 자기확장 모니터링은 모니터링 정보수집과 침입자 추적에 대한 공간적인 제약을 최소화하여 침입탐지와 침입자 추적의 정확도를 높인다.

• 융합보안논문지
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• 제17권3호
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• pp.103-114
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• 2017

테러리즘은 개인적 법익에서부터 국가적 법익에 이르기까지 포괄적인 법익의 침해가 가능하다는 점에 있어 그 심각성이 크다. 그리고 이러한 법적 가치가 훼손될 경우에는 원상회복될 가능성이 매우 희박하므로 제도적 개선 및 대안적 정책을 제시하는 것 못지 않게 사전 예방적 활동의 중요성을 인식하는 것이 선행되어야 한다. 사전 예방적 작용과 절차적 합법성을 담보하기 위해서는 형사사법기관의 역할이 무엇보다 중요한데 구체적 절차 및 법적 접근이 이루어지기 전에 이들의 테러리즘 본질에 대한 인식은 어떠한지 살펴보는 것은 의미가 있을 것이다. 이 연구에서는 이러한 문제 인식을 바탕으로, 대테러리즘 인식을 살펴보기 위한 다양한 기준 중 포괄적 위기관리 모형(Comprehensive Emergency Management Model)에서 제시하고 있는 위기발생의 시차별 진행과정을 기준으로 예방과 완화, 준비, 대응, 복구 등 4단계로 분류하여 인식의 차이를 분석해 보고자 하였다.