• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.561-568
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• 2002

한국원자력연구소에서 개발중인 액체금속로인 KALIMER는 경수로나 증수로와 근본적으로 설계가 상이하므로 PSA 방법에 대한 새로운 접근방법을 개발해야 한다. 액체금속로 KALIMER에 대한 확률론적 안전성 평가 방법 (PSA, Probabilistic Safety Assessment) 관련 연구는 초기 사건의 도출 및 빈도계산 방법과 주요 계통의 신뢰성 예비 평가에 대한 것이다. 초기 사건이란 원전에 과도 현상을 유발하여 발전소 정지를 초래하는 모든 비정상 사건을 의미하는 것으로 PSA에서 사건 수목을 구성하는 데 기본이 되는 정보이다. 액체금속로는 기존의 경수로 및 중수로와는 전혀 다른 설계를 갖고 있으므로 액체금속로 특유의 초기 사건을 도출하는 방법 및 이들 초기 사건의 빈도를 계산하는 방법에 대한 연구를 수행하였다. KALIMER 주요 계통의 신뢰성 예비 평가를 수행하기 위하여 확률론적 안전성 평가에서 계통분석기법으로 널리 이용되는 고장수목분석의 절차와 방법에 대한 방법론을 선정하여 PSA 방법론을 개발하였다.

• Korean Security Journal
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• no.36
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• pp.317-347
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• 2013

This study focuses on the characteristics of terrorist bombing incidents and causal factors on terrorist bombing incidents and number of casualty per incident in Afghanistan though statistical quantitative analysis. For doing so, the bombing data from GTD(Global Terrorism Database) of START program occurred from January 1st 2002 until December 31st 2011 was used. By using descriptive analysis, chi-square, and logistic regression analysis, characteristics of bombing incidents and causal factors on the frequency of incidents and the number of casualty were identified. According to the analysis results, a clear pattern was appeared in terrorist bombing incidents. This result suggests that terrorists rationally and strategically calculate bombing operations and therefore terrorist bombing incidents and number of casualty per incident are conditioned or affected by time, season, Pashtun tribal entity, production level of drugs, the characteristics of targets.

• Journal of Korean Society of Transportation
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• v.35 no.6
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• pp.469-480
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• 2017

On April 1, 2004, KTX (Korea Train eXpress), the first HSR (High-Speed Rail) in Korea, was introduced to Gyeongbu Line. The introduction of the KTX service led to a change in the number of passengers for Gyeongbu Line. Previous studies have analyzed the pre and post-event changes of the intervening events by either simple statistics or intervention ARIMA analysis. However, the intervention ARIMA model has a limitation that several assumptions such as the occurrence time and the type of intervention events are necessary. To this end, this study analyzed the effects of intervention event on the number of passengers using the Gyeongbu line based on a time series outlier detection technique which can overcome limitations in the previous studies. The time series outlier detection technique can analyze the time, effect type and size of an intervention event without the assumption of the time and effect type of the intervention event. The data were collected from the Korea Transport Database (KTDB) for twelve years from 2003 to 2014 (144 months). The analysis results showed that the size of the influence type in the same intervention events was different across the major city routes, and the intervention event which could not be found by previous study methods was also found.

• Journal of the Korean Society for Library and Information Science
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• v.58 no.3
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• pp.359-380
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• 2024

The purpose of this study is to increase understanding of the library use behavior and preferences of the elderly by exploring positive and negative experience factors in the use of public libraries by the elderly. To this end, the Critical Incident Technique (CIT) was applied and individual in-depth interviews were conducted with elderly people who use public libraries. Analysis of the collected data was conducted by applying the constant comparison method, and 12 categories of positive experience factors and 12 categories of negative experience factors were derived under four areas: data, service-program, environment-facility, and emotion. Based on these results, suggestions were made regarding public library services for the elderly.

• 방재와보험
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• s.124
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• pp.48-52
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• 2008

설 연휴가 끝나갈 무렵 발생한 숭례문(국보1호) 화재사건으로 온 나라가 발칵 뒤집혔고 모든 국민은 나의 소중한 일부를 잃어버린 공허함에 형용할 수 없이 참담한 심정으로 하루하루를 살아가고 있다. 언제나 그랬던 것처럼 화재원인의 끝자락에는 여지없이 인재로 귀결되고, 보존관리와 소화과정에 대한 논란도 쉽게 정리되지 않을 듯하다. 우리 주변에는 화재발생 요인도 다양하지만 그 대상물 또한 지니는 특징이 매우 다양하여 소화기법이나 조사기법 등에 있어서도 그 만큼 복잡한 형태를 갖는다. 본 코너에서는 화재로 인해 심각하거나 빈번한 피해를 가져다주는 주요 구조 형태에 따른 화재의 특징을 살펴보고 화재 원인의 유형과 조사기법에 대하여도 논의해 보고자 한다. 숭례문 화재 사건은 현재 조사가 진행 중인 만큼 사찰과 함께 특수 건축물의 유형으로 분류하여 추후 논의할 기회를 가져볼 것이다. 화재의 종류에는 소방관점이나 건축법상의 대상물 등 다양하게 표현되고 분류할 수 있다. 본 코너에서는 이러한 틀에서 벗어나 화재의 특징이 달라질 수 있는 구조나 재료, 형태 등을 달리하는 건축물 또는 구조물별로 화재 현상을 나누어 그들에서 발생하는 화재의 특징을 살펴보고, 사고 후 업무와 관련이 되는 담당자의 관점에서 조사의 요점이나 화재 사례 등을 살펴보고자 한다. 접근 방법에 따라 몇 가지로 분류해 보면 다음과 같이 나누어 볼 수 있다.

• Journal of Intelligence and Information Systems
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• v.24 no.1
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• pp.183-203
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• 2018

News articles are the most suitable medium for examining the events occurring at home and abroad. Especially, as the development of information and communication technology has brought various kinds of online news media, the news about the events occurring in society has increased greatly. So automatically summarizing key events from massive amounts of news data will help users to look at many of the events at a glance. In addition, if we build and provide an event network based on the relevance of events, it will be able to greatly help the reader in understanding the current events. In this study, we propose a method for extracting event networks from large news text data. To this end, we first collected Korean political and social articles from March 2016 to March 2017, and integrated the synonyms by leaving only meaningful words through preprocessing using NPMI and Word2Vec. Latent Dirichlet allocation (LDA) topic modeling was used to calculate the subject distribution by date and to find the peak of the subject distribution and to detect the event. A total of 32 topics were extracted from the topic modeling, and the point of occurrence of the event was deduced by looking at the point at which each subject distribution surged. As a result, a total of 85 events were detected, but the final 16 events were filtered and presented using the Gaussian smoothing technique. We also calculated the relevance score between events detected to construct the event network. Using the cosine coefficient between the co-occurred events, we calculated the relevance between the events and connected the events to construct the event network. Finally, we set up the event network by setting each event to each vertex and the relevance score between events to the vertices connecting the vertices. The event network constructed in our methods helped us to sort out major events in the political and social fields in Korea that occurred in the last one year in chronological order and at the same time identify which events are related to certain events. Our approach differs from existing event detection methods in that LDA topic modeling makes it possible to easily analyze large amounts of data and to identify the relevance of events that were difficult to detect in existing event detection. We applied various text mining techniques and Word2vec technique in the text preprocessing to improve the accuracy of the extraction of proper nouns and synthetic nouns, which have been difficult in analyzing existing Korean texts, can be found. In this study, the detection and network configuration techniques of the event have the following advantages in practical application. First, LDA topic modeling, which is unsupervised learning, can easily analyze subject and topic words and distribution from huge amount of data. Also, by using the date information of the collected news articles, it is possible to express the distribution by topic in a time series. Second, we can find out the connection of events in the form of present and summarized form by calculating relevance score and constructing event network by using simultaneous occurrence of topics that are difficult to grasp in existing event detection. It can be seen from the fact that the inter-event relevance-based event network proposed in this study was actually constructed in order of occurrence time. It is also possible to identify what happened as a starting point for a series of events through the event network. The limitation of this study is that the characteristics of LDA topic modeling have different results according to the initial parameters and the number of subjects, and the subject and event name of the analysis result should be given by the subjective judgment of the researcher. Also, since each topic is assumed to be exclusive and independent, it does not take into account the relevance between themes. Subsequent studies need to calculate the relevance between events that are not covered in this study or those that belong to the same subject.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1815-1829
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• 2014

Recently frequent collapse of old fill dams has taken place, which increases social awareness in the safety of the infrastructure. Fill dams in Korea has been incautiously regarded as safe once the fill dam is considered to have a full capacity to retain a conservative design flood determined by government authorities. However, developed foreign countries has been managing their fill dams by introducing systematic risk assessment techniques over a long period of time. In this study, the system response probabilities of the deteriorated old fill dams in Korea were systematically evaluated and analyzed by using the internal erosion toolbox based on the event tree analysis technique. The probability of the existence of flaw and the magnitude of the hydraulic gradient through a potential crack can significantly influence the geotechnical system response probability. The results of this study show that the probability of the existence of flaw and the magnitude of the hydraulic gradient through a potential crack can significantly influence the geotechnical system response probability and the risk of the deteriorated fill dam can be quantitatively assessed.

• The Journal of the Korea Contents Association
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• v.15 no.6
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• pp.606-615
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• 2015

This study aims to provide suggestions for the development of educational contents on historical events that can solve the existing curriculum's problems, such as the disproportionate weight given to Western historical events. The study focuses on content ranging from the start of the Agricultural Revolution (7000 BC.) to the start of the Industrial Revolution (AD. 1760). The results are as follows. We used the Delphi technique for deriving global historical events. Among them, 56 historical events were selected as the data for Social Network Analysis (SNA). The results of SNA showed that topics related to Civilization has a high priority. In addition, the results of a coagulation analysis showed the events can be divided into seven groups. The classification criteria is different from the criteria used for the current period. We expect that the suggested framework developed for historical contents will constitute a new approach to historical interpretation through network visualization and linkage analysis.

• Knowledge Management Research
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• v.25 no.1
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• pp.1-19
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• 2024

This study analyzed the changes in social media reactions of data subjects to major personal data breach incidents in South Korea from January 2014 to October 2022. We collected a total of 1,317 posts written on Naver Blogs within a week immediately following each incident. Applying the LDA topic modeling technique to these posts, five main topics were identified: personal data breaches, hacking, information technology, etc. Analyzing the temporal changes in topic distribution, we found that immediately after a data breach incident, the proportion of topics directly mentioning the incident was the highest. However, as time passed, the proportion of mentions related indirectly to the personal data breach increased. This suggests that the attention of data subjects shifts from the specific incident to related topics over time, and interest in personal data protection also decreases. The findings of this study imply a future need for research on the changes in privacy awareness of data subjects following personal data breach incidents.

• Korean Security Journal
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• no.18
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• pp.73-99
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• 2009

There are three assassination and treatening cases in this thesis introduced as analysis data. They are shooting accidents of the U.S.A's President Reagun (1981,3.30), and the President Park Jeong Hee of South Korea(1974.8.15), assassination of the Prime Minister Lavin of Israel (1995.11.4) In March 30, 1981, there was an accident where criminal, Hinckley, fired ball cartridges right before the President Reagan got into the car to move to White House after completing the announcement of Hilton Hotel of Washington. As a result, the chest of president was shot and public information secretary and safeguard were wounded. In August, 15, pm 10:23, where the 29th 8.15 independent anniversay event was being celebrated by the people at the National theater in Jangchungdong, Seoul, the criminal Moon Sekwang fired ball cartridges, he failed to assassinate the President Park Jeong Hee of Korea, but shot the First lady Yuk Young Soo. She was wounded right part of head and died. In November 4, Saturday, pm 22:00 the Prime Minster Lavin had finished the supporting event of Middle Asia's Peace project and was taking on the car when he was killed by the criminal Amir's shooting, The accidents left very important lesson from the aspect of security analysis and it has been frequently used as a material for the education and training of safeguard organization. In Korea, as well as Presidential Security Service, national security departments have selected it as an important model for the subjects such as 'Security Analysis, 'Security Practice' and 'Security Methodology'. In the performance of security duty, security skill is the most important matter. Moreover, it has a close relationship with politics, society and culture. The purpose of this study is to analyze and reevaluate the case, which has been treated as a usual model from the aspect of security analysis, beyond its introduction. Attempted assassination of President Reagan was evaluated as a positive success example because of its rapid response of adjacent guards to evacuate Reagan, who is a guard target, within 10 seconds after the shot. When comparing it to President Kennedy Assassination of 1963, it was evaluated that guards were significantly specialized. In the study, however, it was possible to found many problems such as carelessness of guard, who is in charge of external area of event place, idle attitude for frequently used event place, confusion of wireless communication, risk of wireless security disclose, insufficient provision of compulsory record file, insufficient profiling of dangerous person and unsecured hospital and first-aid room.