• International Journal of Naval Architecture and Ocean Engineering
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• 제10권3호
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• pp.393-402
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• 2018

While interacting with a sloping structure, an ice floe may fracture in different patterns. For example, it can be local bending failure or global splitting failure depending on the contact properties, geometry and confinement of the ice floe. Modelling these different fracture patterns as a natural outcome of numerical simulations is rather challenging. This is mainly because the effects of crack propagation, crack branching, multi fracturing modes and eventual fragmentation within a solid material are still questions to be answered by the on-going research in the Computational Mechanic community. In order to simulate the fracturing of ice floes with arbitrary geometries and confinement; and also to simulate the fracturing events at such a large scale yet with sufficient efficiency, we propose a semi-analytical/empirical and semi-numerical approach; but with focus on the global splitting failure mode in this paper. The simulation method is validated against data we collected during the Oden Arctic Technology Research Cruise 2015 (OATRC2015). The data include: 1) camera images based on which we specify the exact geometry of ice floes before and after an impact and fracturing event; 2) IMU data based on which the global dynamic force encountered by the icebreaker is extracted for the impact event. It was found that this method presents reasonably accurate results and realistic fracturing patterns upon given ice floes.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1017-1023
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• 2022

Past research shows that the construction of new infrastructure accelerates economic growth in the region by attracting more people and commodities. However, the previous studies only considered large-scale infrastructures such as sea-cross bridges and channel tunnels. There is a paucity of literature on regional infrastructure and its impact on socio-economic indicators. This paper explores the impact of new bridge construction on the human population, particularly focusing on regional bridges constructed during the 2000s in the state of Georgia. The human population at a county level was selected as a single socio-economic factor to be evaluated. A total of 124 cases were investigated as to whether the emergence of a new bridge affected the population change. The interrupted time series analysis was used to statistically examine the significance of population change due to the construction by treating each new bridge as an intervention event. The results show that, out of the 124 cases, the population of 67 cases significantly increased after the bridge construction, while the population of 57 cases was not affected by the construction at a significance level of 0.05. The 124 cases were also analyzed by route type, functional class, and traffic volume, but the results revealed, unlike large-scale infrastructure, that no clear evidence was found that a new bridge would bring an increase in the human population at a county level.

• 환경영향평가
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• 제18권6호
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• pp.347-357
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• 2009

This study conducted a vulnerability assessment on Korea's physical infrastructure to provide base data for developing strategies to strengthen Korea's ability to adapt to climate change. The assessment was conducted by surveying professionals in the field of infrastructure and climate change science. A vulnerability assessment was carried out for seven climate change events: average temperature increases, sea level rise, typhoons and storm surges, floods and heavy rain, drought, severe cold, and heat waves. The survey asked respondents questions with respect to the consequences of each climate change event, the urgency of adaptation to climate change, and the scale of investment for adaptation to each climate change event. Thereafter, management priorities for infrastructure were devised and implications for policy development were suggested. The results showed that respondents expected the possibility of "typhoons and storm surges" and "floods and heavy rain" to be the most high. Respondents indicated that infrastructure related to water, transportation, and the built environment were more vulnerable to climate change. The most vulnerable facilities included river related facilities such as dams and riverbanks in the "water" category and seaports and roads in the "transport and communication" category. The results found were consistent with the history of natural disasters in Korea.

• 정신신체의학
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• 제29권2호
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• pp.136-143
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• 2021

연구목적 코로나바이러스 사태로 인해 전세계가 보건 위기와 큰 혼란의 국면을 맞은 가운데, 특히 재난 상황에서 시민의 건강을 위해 노력하는 공공 근로자들의 신체적, 정신적 스트레스가 과중해지고 있다. 본 연구는 공공 근로자들의 정신적 스트레스를 분석하고자 했다. 방 법 본 연구에서는 광명시 정신건강복지센터 홈페이지를 통해 모집한 531명의 공공영역 종사자를 대상으로 한국판 지각된 스트레스 척 도(Perceived Stress Scale, PSS), 한국판 우울증 평가도구(Patient Health Questionnaire-9, PHQ-9), 한국판 사건 충격 척도 수정판(Impact Event Scale-Revised, IES-R-K)을 시행하였다. 결 과 분석 결과에 의하면 코로나 19 관련 종사자들은 중등도 이상의 지각된 스트레스 반응(85.2%), 우울증상(22.2%), 외상 후 스트레스 관련 증 상(38.8%)을 보여, 상당한 스트레스와 우울증상을 경험하는 상태로 나타났다. PSS 총점은 PHQ-9, IES-R 총 점 및 IES-R의 하위 척도별 점수와 유의한 상관관계를 보여, 주관적으로 지각된 스트레스 반응 정도가 우울 증상과 연관되어 있음을 시사하였다. PSS, PHQ-9, IES-R 총점은 각각 모두 연령과 음의 상관관계를 보였다. 즉, 연령이 직무 스트레스 반응과 번아웃에 대한 보호요인으로 작용할 가능성이 있다. 결 론 향후에 공공영역 종사자 들의 정신건강에 관한 추가적인 연구가 필요하겠으며 정신건강 관리 및 적절한 개입이 마련되어야 할 것으로 사료된다.

• 생물정신의학
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• 제8권1호
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• pp.131-139
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• 2001

This study was conducted to evaluate the effect of PTSD on memory function and hippocampal volume, and to identify major variables correlated to hippocampal volume and memory function. Thirty four Vietnam veterans were collected for this study, among whom eighteen were PTSD patients and sixteen were combat control subjects. The author used Impact of Event Scale(IES), Combat Exposure Scale(CES), Hamilton Depression Rating Scale(HDRS) and Beck Depression Inventory (BDI). Korea Memory Assessment Scale(K-MAS) was assessed for memory function. Magnetic resonance imaging(MRI) was used to measure hippocampal volume. There were significant differences between PTSD and Non-PTSD veterans in IES, HDRS and BDI. Significant difference was found in verbal memory and total memory of K-MAS between PTSD and Non-PTSD veterans. There was significant difference in hippocampal volume between PTSD and Non-PTSD veterans. Short term memory, verbal memory and total memory were positively correlated to hippocampal volume. Hippocampal volume was negatively correlated to IES, HDRS, and BDI. These results suggest that PTSD severity be associated with hippocampal atrophy and memory dysfunction. Reduced or smaller hippocampal volume may be preexisting risk factor for stress exposure or the development of PTSD on combat exposure.

• 한국농공학회논문집
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• 제62권3호
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• pp.109-121
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• 2020

Converting the agricultural land-use of rice field to upland has been increasingly conducted as farmers encourages themselves to grow higher value-added crops on rice fields under the policy support. Comparing to rice field, Upland shows different characteristic of discharge due to the slope, scale, and shape of field and characteristics of rainfall event. In this study, we designed the experiment fields reflecting flat-upland characteristics with different land scale, and tried to collect the discharge and load data. Soybeans and corn were selected as target crops considering the possibility of large-scale cultivation and crop demand. The cultivation was conducted during the growth period in 2019 with 3 different field scales. Hence, we have collected the discharge data from 17 rainfall events and the load data for 8 rainfall events. As a result, the magnitude of rainfall events and the discharge duration were found to have a strong positive correlation and field discharge occurred during the period by 55% to 83% of rainfall duration. Besides we found other relationships and characteristics of rainfall event, discharge, and pollutant load and also pointed out that continuous monitoring and more data are required to derive statistically significant results. Compared with slope-field monitoring data obtained from the precedent research, the runoff ratio of the flat-fields was significantly lower than slope-fields. Overall the discharge in the slop and flat-fields shows appreciably different characteristics so that the related researches need to be further conducted to reasonably assess environmental impact of agricultural activities at flat-field.

• 정신신체의학
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• 제29권2호
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• pp.191-198
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• 2021

연구목적 화상 환자의 방어 기제에 따른 외상 후 스트레스 증상의 정도를 알아보고자 이 연구를 수행하였다. 방 법 화상을 진단받은 환자 40명을 대상으로 사회 인구학적 특성, 화상 관련 특성, 한국판 사건충격척도 개정판(Impact of Event Scale-Revised, IES-R), 한국판 역학조사 우울증 척도(Center for epidemiologic studies depression scale, CES-D), 이화방어기제(Ewha Defense Mechanisms Test, EDMT)를 측정한 후 다중회귀분석을 실시하였다. 결 과 자아 확대적 방식으로 구성된 EDMT의 요인 2의 점수가 IES-R 점수와 통계학적으로 유의한 상관관계가 있었으며(β=-0.318, p=0.018), EDMT의 요인 2중에서는 통제(β=-0.299, p<0.05), 이타주의(β=-0.276, p<0.05)가 IES-R점수와 통계학적으로 유의한 상관관계가 있었다. 결 론 이 연구에서 화상 환자의 외상 후 스트레스장애는 통제, 이타주의 방어 기제와 상관성이 있었으며 화상 환자의 치료에 있어 방어 기제를 평가하는 것은 추후 외상 후 스트레스 장애의 심각도 판단에 도움을 줄 것으로 생각된다.

• 대한불안의학회지
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• 제12권1호
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• pp.28-33
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• 2016

Objective : One of the aims of this study was to confirm the relationship in firefighters who have a high risk of developing posttraumatic stress disorder. We also explored the mediation effects of resilience and posttraumatic growth (PTG) on the association between traumatic experiences and posttraumatic stress symptoms. Methods : A total of 677 firefighters were assessed in terms of the intensity of job-related traumatic experiences using the Visual Analogue Scale. They completed the Korean version of the Posttraumatic Growth Inventory (PTGI), the Korean version of the Impact of Event Scale-Revised (IES-R), and the Korean version of the 10-item Connor-Davidson Resilience Scale (CD-RISC-10). Results : The intensity of traumatic experiences was significantly negatively related to the CD-RISC-10 score, but it was positively related to the PTGI and the IES-R scores. The CD-RISC-10 score had a significantly positive correlation with the PTGI score, but it was negatively correlated to the IES-R score. Path analyses revealed that resilience and PTG independently mediated the association between traumatic experiences and posttraumatic stress symptoms. Conclusion : These results suggest that traumatic experiences contribute to posttraumatic stress symptoms and that these impacts may be mediated through resilience and PTG.

• 수면정신생리
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• 제17권1호
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• pp.28-33
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• 2010

목 적: 근무패턴 중 일반적인 생리 스케줄에 반한 교대순환근무가 개인의 신체적, 정신적 건강을 위협한다는 고민은 계속되어 왔다. 본 연구에서는 대표적인 교대순환근무가 이루어지고 있는 경찰 공무원을 대상으로, 주간고정근무자와 비교하였을 때 교대순환 근무자에서 수면의 질, 직무스트레스, 사건충격척도, 우울증상에 있어 차이가 있는지를 조사해 보고자 하였다. 방 법: 일 도시 지역 경찰공무원 1,145명(남성 1,040명, 여성 105명)을 대상으로 하였다. 연구 대상자들의 일반적 특성으로 근무 형태를 비롯한 사회 인구학적 정보를 조사하였고, 지난 한달 동안의 수면의 질(Pittsburgh Sleep Quality Index; 이하 PSQI), 직무스트레스척도(Korean Scale of Occupational Stress; 이하 KOSS), 사건 충격 척도 개정판(Impact of Event Scale-Revised; 이하 IES-R), 우울증 척도(Center for Epidemiologic Study-Depression; 이하 CES-D)로 구성된 설문지를 작성하도록 하였다. 결 과: 전체 대상군 중 98명(9.4%)이 CES-D 점수가 16점이 넘는 경도 이상 우울증상이 있는 집단으로 분류되었다(순환교대근무자의 9.2%, 주간고정근무자의 7.8%; 남성의 7.6%, 여성의 18.1%). 순환교대근무와 주간고정근무의 근무형태 별 CES-D 점수 평균의 차이는 통계적으로 유의하지 않았다(표 1; t=1.766, p=0.078). PSQI 점수 5점 초과의 '낮은 수면의 질'에 해당하는 군은 전체 대상군 중 178명(15.5%)으로 순환교대근무자의 18.0%, 주간근무자의 13.51%가 이에 해당되었고, 두 군 간의 점수 평균의 차이는 유의미했다(t=-1.958, p=0.050). 근무 형태 별 KOSS 평균 점수 역시 두 군 간 차이가 존재했으며(t=-2.895, p=0.004), IES-R 평균 점수에서도 유의미한 차이를 보였다(t=-2.067, p=0.039). 전체 대상군의 상관관계분석에서 나이와 성별, 학력을 보정한 후, CES-D 점수는 KOSS, PSQI, IES-R 점수와 유의한 양의 상관관계를 보였다(각각 r=0.262; p<0.000, r=0.228; p<0.000; r=0.421, p<0.000). CES-D 점수 16점 이상의 경도 이상 우울증상을 종속변수로 하고, 성별, 나이, 학력, PSQI 점수, KOSS 점수, IESR 점수, 근무형태를 독립변수로 로지스틱 회귀분석을 시행하였다. 이 중 성별(여성), 나이(20대), 높은 KOSS 점수, 높은 IES-R 점수와 교대순환 근무 여부가 CES-D 16점 이상의 우울증상을 유의하게 예측하였다(각각 Wald=5.167; p=0.023, Wald=10.432; p=0.015, Wald=41.596; p=0.000, Wald=51.784; p=0.000, Wald=5.270, p=0.022). PSQI 점수는 경도 이상의 우울증상을 유의하게 예측하지 못하였다(Wald=0.898; p=0.343). 결 론; 본 연구결과는 경찰 공무원의 우울증상에 여성, 나이, 높은 직무 스트레스와 사건충격 점수뿐 아니라 교대순환 근무 역시 우울 위험도를 높이는 인자임을 제시한다.

• Safety and Health at Work
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• 제8권4호
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• pp.410-412
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• 2017

Post-traumatic stress disorder (PTSD) is a serious problem not only among workers who experience industrial accidents but also among workers who witness such accidents. Early intervention is needed to prevent prolonged psychological problems. There has been no study conducted regarding the psychological problems of and interventions for bystander workers in Korea. This study introduces the experience of intervention on psychological problems at the Busan Workers' Health Center workers who witnessed their colleagues' death. An investigation and an intervention were conducted according to the Korean Occupational Safety and Health Agency (KOSHA) Guide. In total, 21 individuals including indirect observers showed statistical differences on scores of the Impact Event Scale Revised and the Patient Health Questionnaire 9 after the intervention. Future interventions and research involving a larger sample size over a longer period are needed. The KOSHA Guide could be a useful tool for urgent psychological intervention in the event of major workplace disasters.