• 한국산학기술학회논문지
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• 제21권10호
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• pp.421-432
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• 2020

본 연구의 목적은 초등학교 고학년 학생의 인터넷 게임 및 스마트폰 이용실태를 파악하고자 하였다. 2018년 10월 6일부터 2019년 9월 30일까지 K 지역 소재 16개 초등학교에 재학 중인 4~6학년 1,618명을 대상으로 자료를 수집하였고, 기술통계와 빈도분석, Chi-square를 이용하여 분석하였다. 연구결과, 인터넷 게임중독 자가진단척도(I-GUESS)는 고위험군이 6.1%로 나타났고, 스마트폰 과의존 척도(S-scale)는 잠재적 위험군 10.1%, 고위험군 0.8%로 나타났다. 인터넷 게임 및 스마트폰 사용과 관련된 신체적 문제는 36.0%가 경험했다고 응답했고, 눈의 피로가 20.4%로 가장 높았다. 정서적 문제는 18.5%에서 경험했다고 응답했으며, 분노가 6.8%로 가장 높았다. 사회적 문제는 21.8%가 경험한 것으로 파악되었고, 부모와의 갈등이 10.3%로 가장 높게 보고되었다. S-scale 점수와 I-GUESS 점수에 따른 주 사용 콘텐츠를 조사한 결과, S-scale 점수와 I-GUESS 점수가 높을수록 중계방송콘텐츠를 가장 많이 사용하는 것으로 나타났다. I-GUESS와 S-Scale 간의 상관관계에서는 I-GUESS와 S-Scale 간의 상관관계에서는 I-GUESS 점수가 고위험군 일수록, S-scale의 고위험군 비율도 높게 나타났으며, S-scale 점수가 고위험군 일수록 I-GUESS 점수의 고위험군 비율도 높은 것으로 나타났다. 향후, 이러한 변수를 고려하여 예방의 관점에서 초등학생을 위한 중재 프로그램 및 부모 교육 컨텐츠 개발이 시급함을 제언코자 한다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.683-686
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• 2008

Flood damage has been increased due to the abnormal climate and extreme rainfall. So, quantitative and qualitative hydrologic data should be improved in oder to enhance accuracy of hydrologic forecast. However, research regarding hydrologic data have not been thorough enough. Therefore, in this study, monte carlo simulation was applied to rainfall runoff model to improve the reliability of runoff analysis and risk analysis. Rainfall-Stage-Discharge curve was developed as a consequence of MCS and it is possible to get correct rating curve for high water level.

• 한국신뢰성학회지:신뢰성응용연구
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• 제10권1호
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• pp.73-91
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• 2010

All activities relate to railway traffic involve risk and that these arise from a combination of the nature of operating activities. Proper management system is required to provide the organizational capability to reveal, analyse and address these weaknesses over time and in reasonably practicable ways, which will determine the rate at which risks can be further reduced. This paper presents a systematic risk analysis approach to safety planning and decision making, informed by a range of risk assessment techniques. An railway organization's safety management system is also presented that shows the approaches taken to minimize the external risks, and identify the shared risks and explain how they will be controlled through collaboration with others.

• 대한전기학회논문지:전력기술부문A
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• 제55권10호
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• pp.426-432
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• 2006

This paper describes the concepts of Static Line Rating (SLR) and Dynamic Line Rating (DLR) and the computational methods to demonstrate them. Calculation of the line capacity needs the heat balance equation which is also used for computing the reduced tension in terms of line aging. SLR is calculated with the data from the worst condition of weather throughout the year. Even now, the utilization ratio is obtained from this SLR data in Korea. DLR is the improved method compared to SLR. A process for DLR reveals not only improved line ratings but also more accurate allowed line ratings based on line aging and real time conditions of weather. In order to reflect overhead transmission line aging in DLR, this paper proposes the method that considers the amount of decreased tension since the lines have been installed. Therefore, the continuous allowed temperature for remaining life time is newly acquired. In order to forecast DLR, this paper uses weather forecast models, and applies the concept of Thermal Overload Risk Probability (TORP). Then, the new concept of Dynamic Utilization Ratio (DUR) is defined, replacing Static Utilization Ratio (SUR). For the case study, the two main transmission lines which are responsible for the north bound power flow in the Seoul metropolitan area are chosen for computing line rating and utilization ratio. And then line rating and utilization ratio are analyzed for each transmission line, so that comparison of the present and estimated utilization ratios becomes available. Finally, this paper proves the validity of predictive DUR as the objective index, with simulations of emergency state caused by system outages, overload and so on.

• 산경연구논집
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• 제7권2호
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• pp.13-20
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• 2016

Purpose - The purpose of this research is to discover whether the presence of the product average rating introduces biases or change the way people perceive information. We posit that review's overall rating has a predisposition effect on consumers' perception towards detailed review information. Research design, data, and methodology - To test these hypotheses, we conducted an empirical study on a real-world setting of online shopping platform. We choose the Amazon website to test our results. The data we use were collected by the Stanford Network Analysis Project1 (McAuley et al., 2013). Results - With a dataset containing reviews of seven product categories from amazon.com., our findings could possess more generalizability as they are produced on the typical and influential online market. Second, as our research provides alternative views of consumers' shopping behavior, it is better to test our hypotheses by data from the same source. Conclusions - Our study reveals the impact of the collective rating presence on consumers' diagnosticity perception and sheds light upon some of the conflictive results in prior studies. Our research generates implications to both theories and business practices, and suggests future directions for the research question.

• 산경연구논집
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• 제13권1호
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• pp.23-32
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• 2022

Purpose: This study used ESG grade, but defined AESG, adjusted to the size of a company and examines whether it can be used as an investment strategy. Research design, data and methodology: The analysis sample in this study is a company that has given an ESG rating among companies listed on the Korea Stock Exchange. We examine the results through portfolio analysis and Fama-macbeth regression analysis. Results: As result of examining the long-only performance and the long-short performance by constructing quintile portfolios, it was observed that a significant positive return was shown. It was observed that there was an alpha that could not be explained in asset pricing models. Also, AESG had a return prediction effect in the result of a Fama-Macbeth regression that controlled corporate characteristic variables in individual stocks. Next, we confirmed AESG's usage through various portfolio composition. In the portfolio optimization, the Risk Efficient method was the most superior in terms of sharpe ratio and the construct multi-factor model with Value, Momentum and Low Vol showed statistically significant performance improvement. Conclusions: The results of this study suggest that it can be helpful in ESG investment to reflect the ESG rating of relatively small companies more through the scale adjustment of the ESG rating (i.e.AESG).

• 생물정신의학
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• 제12권2호
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• pp.189-195
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• 2005

Objects:Some studies have suggested that brain-derived neurotrophic factor(BDNF), one of the most important neurotrophins, is involved in pathophysiology of depression and suicide. This study was performed to determine whether there is an abnormality in plasma BDNF concentration in suicidal attempters. Methods:The subjects were 71 suicidal attempters who visited emergency rooms in multi-medical centers. All subjects had been interviewed by using Structured Clinical Interview for DSM-IV(SCID), Hamilton Depression Rating Scale(HDRS), Young Mania Rating Scale(YMRS), and Positive And Negative Syndrome Scale(PANSS). The severity of the suicidal behavior was measured by Lethality of Suicide Attempt Rating Scale(LSARS) and Risk-Rescue Rating(RRR) system. Seventy-one age, sex, and diagnosis matched non-suicidal psychiatric patients who were consecutively admitted to a psychiatric ward during the same period recruited as psychiatric controls. They were drug-naive or drug-free at least more than 2 months. In addition, 80 healthy controls were randomly selected as normal controls. Plasma BDNF level was measured by the enzyme linked immunosorbent assay(ELISA) methods. Results:In overall F-test, differences of the plasma BDNF levels among the groups were statistically significant(F=20.226, p<0.001). In the multiple comparisons(Scheffe), while mean levels of plasma BDNF between normal controls and non-suicidal psychiatric patients were similar(p=0.984), the BDNF levels of suicidal attempters were lower than those of other two groups(p<0.001). LSARS and RRR did not reveal any significant correlations with BDNF levels in suicidal attempters. Conclusion:These results suggest that reduction of plasma BDNF level is related to suicidal behavior and BDNF level may be a biological marker of suicidal behavior.

• 한국전기전자재료학회논문지
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• 제36권6호
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• pp.598-602
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• 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.

• 정신신체의학
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• 제24권2호
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• pp.236-243
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• 2016

연구목적 본 연구는 자살시도에서 알코올이 자살시도의 심각성 및 치명도에 미치는 영향이 성별에 따라 차이가 있는 지 여부를 확인하고자 하였다. 방 법 총 1,152명의 자살시도자(남성 487명, 여성 742명)를 분석 대상으로 하였으며, 음주 양상에 따라 알코올사용 장애군, 급성알코올사용군, 비알코올사용군으로 나누었다. 자살시도의 심각성과 치명도는 자살의도척도및 위험-구조평가척도로 평가하였다. 결 과 남성에서는 급성알코올사용군에 비해 알코올사용장애군에서 자살의도척도의 총점이 유의하게 낮았지만, 여성에서는 각 군 사이에 유의한 차이가 없었다. 위험-구조평가척도에서 남성은 각 군간에 차이가 없었으나, 여성은 알코올사용장애군에서 가장 높은 구조도와 가장 낮은 위험도 점수를 보였다. 결 론 알코올사용장애가 있는 여성 자살시도자는 구조가 쉬운 상황에서 충동적인 자살 시도를 하는 경향이 있다면, 남성은 알코올 사용장애 환자보다 급성 알코올 중독상태일 때 자살의도가 더 강했다. 자살시도자의 알코올의 사용이 성별에 따라 다른 영향을 미칠 수 있으며, 특히 여성에서 중요한 위험 요인임을 시사하고 있다.

• 산업융합연구
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• 제21권7호
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• pp.29-39
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• 2023

최근 국내‧외적으로 많은 지진이 발생하고 있는 상황에서, 우리나라의 건물은 내진설계 및 지진피해에 매우 취약한 상황이다. 따라서 현 연구의 목적은 건물에 대한 지진취약도 등급화 및 위험건물 밀도분석을 수행하는 효과적인 방법을 발굴하고 이를 모델화하여, 시범지역(서울시)자료를 활용해 검증해 보는데 있다. 이를 위해 활용된 두 가지 모델링 기법 중, 통계 분석 기법의 예측정확도는 87%였고, 머신러닝 기법은 Random Forest모델의 예측정확도가 가장 높았으며, 해당 모델의 Test Set 정확도는 97.1%로 도출되었다. 분석결과, 구별 등급화 결과는 광진구와 송파구가 상대적으로 위험하다고 예측되었으며, 위험건물 밀도분석은 서초구, 관악구, 강서구가 상대적으로 위험하다고 예측되었다. 최종적으로, 통계분석 기법을 활용한 분석결과가 머신러닝 기법을 활용한 분석결과보다 위험하게 도출되었으나, 우리나라에서는 지진 강도 6.5(MMI)가 내진설계의 기준인데, 서울시 건물의 약 18.9%가 내진설계 되어있는 것으로 확인된 것을 고려하면, 머신러닝 기법의 결과가 더 정확할 것으로 예측되었다. 현 연구는 인구 및 인프라와 경찰서, 소방서 등을 고려 않은 오직 건물만을 고려한 한계점이 있으며, 해당 한계를 포함해 수행하면 더욱 포괄적인 연구가 될 것이다.