대학교 재학생에서 Fatigue Severity Scale의 신뢰도 및 타당도 연구

이정현,정현석,임수미,조한별,마지영,고은,임주연,이선혜,배수진,이유진,류인균,정도언,Lee, Junghyun H.,Jeong, Hyeonseok S.,Lim, Soo Mee,Cho, Han Byul,Ma, Ji-Young,Ko, Eun,Im, Jooyeon J.,Lee, Sun Hea,Bae, Sujin,Lee, Yu-Jin,Lyoo, In Kyoon,Je 대한생물정신의학회 2013 생물정신의학 Vol.20 No.1

Objectives There are only a limited number of studies on instruments assessing fatigue in university students, although fatigue exerts negative influences on their health and academic performances and fatigue-related complaints are more frequently reported in young adults than middle-aged adults. The aim of this study was to validate the 9-item Fatigue Severity Scale (FSS) among university students including both undergraduate and graduate students in South Korea. Methods A total of 176 university students completed a battery of self-report questionnaires, including the FSS, the Brief Fatigue Inventory (BFI), the Beck Depression Inventory-II (BDI-II), the Beck Anxiety Inventory (BAI), the Medical Outcomes Study Short Form 36 version 2 (MOS-SF36v2), and the Inclusion of Community in the Self Scale (ICS). The data were collected from February of 2012 to June of 2012. The reliability, convergent validity, divergent validity, and exploratory factor analyses were conducted to assess psychometric properties of the FSS. Results The mean FSS score was 3.20 (standard deviation = 1.43). The FSS demonstrated an excellent internal consistency (Cronbach's ${\alpha}$ = 0.93) and item-total correlations ranged from 0.56 to 0.90. Correlations of the FSS with the BFI (r = 0.71, p < 0.01), BDI-II (r = 0.54, p < 0.01), BAI (r = 0.46, p < 0.01), MOS-SF36v2 physical component summary (r = -0.28, p < 0.01), MOS-SF36v2 mental component summary (r = -0.55, p < 0.01), and ICS (Spearman's rho = -0.07, p = 0.33) showed acceptable convergent and divergent validity. Exploratory factor analysis defined one underlying factor (eigenvalue = 5.67) that explained 93.50% of the total variance. Conclusions To the best of our knowledge, this is the first study to investigate reliability and validity of the FSS in university students. The FSS exhibits good psychometric properties for evaluation of fatigue among university students in South Korea. Since the FSS is easy to administer, score, and interpret, it could be a useful tool in research and practice for assessing fatigue among university students.

신 흡수제(KoSol-5)를 적용한 0.1 MW급 Test Bed CO₂ 포집 성능시험

이정현,김범주,신수현,곽노상,이동욱,이지현,심재구,Lee, Junghyun,Kim, Beom-Ju,Shin, Su Hyun,kwak, No-Sang,Lee, Dong Woog,Lee, Ji Hyun,Shim, Jae-Goo 한국공업화학회 2016 공업화학 Vol.27 No.4

한전 전력연구원에서 개발한 고효율 아민계 습식 $CO_2$ 흡수제(KoSol-5)를 적용하여 0.1 MW급 Test Bed $CO_2$ 포집 성능시험을 수행하였다. 500 MW급 석탄화력발전소에서 발생되는 연소 배가스를 적용하여 하루 2톤의 $CO_2$를 처리할 수 있는 연소 후 $CO_2$ 포집기술의 성능을 확인하였으며 또한 국내에서는 유일하게 재생에너지 소비량을 실험적으로 측정함으로써 KoSol-5 흡수제의 성능에 대한 신뢰성 있는 데이터를 제시하고자 하였다. 그리고 주요 공정변수 운전 및 흡수탑 인터쿨링 효율 향상에 따른 에너지 저감 효과를 테스트하였다. 흡수탑에서의 $CO_2$ 제거율은 국제에너지기구 산하 온실가스 프로그램(IEA-GHG)에서 제시하는 $CO_2$ 포집기술 성능평가 기준치($CO_2$ 제거율: 90%)를 안정적으로 유지하였다. 또한 흡수제(KoSol-5)의 재생을 위한 스팀 사용량(재생에너지)은 $2.95GJ/tonCO_2$가 소비되는 것으로 산출되었는데 이는 기존 상용 흡수제(MEA, Monoethanol amine)의 평균 재생에너지 수준(약 $4.0GJ/tonCO_2$) 대비 약 26% 저감 된 수치이다. 본 연구를 통해 한전 전력연구원에서 개발한 KoSol-5 흡수제 및 $CO_2$ 포집 공정의 우수한 $CO_2$ 포집 성능을 확인할 수 있었고, 향후 본 연구에서 성능이 확인된 고효율 흡수제(KoSol-5)를 실증급 $CO_2$ 포집플랜트에 적용할 경우 $CO_2$ 포집비용을 크게 낮출 수 있을 것으로 기대된다. The absorption efficiency of amine $CO_2$ absorbent (KoSol-5) developed by KEPCO research institute was evaluated using a 0.1 MW test bed. The performance of post-combustion technology to capture two tons of $CO_2$ per day from a slipstream of the flue gas from a 500 MW coal-fired power station was first confirmed in Korea. Also the analysis of the absorbent regeneration energy was conducted to suggest the reliable data for the KoSol-5 absorbent performance. And we tested energy reduction effects by improving the absorption tower inter-cooling system. Overall results showed that the $CO_2$ removal rate met the technical guideline ($CO_2$ removal rate : 90%) suggested by IEA-GHG. Also the regeneration energy of the KoSol-5 showed about $3.05GJ/tonCO_2$ which was about 25% reduction in the regeneration energy compared to that of using the commercial absorbent MEA (Monoethanolamine). Based on current experiments, the KoSol-5 absorbent showed high efficiency for $CO_2$ capture. It is expected that the application of KoSol-5 to commercial scale $CO_2$ capture plants could dramatically reduce $CO_2$ capture costs.

경찰공무원에서 외상후스트레스장애와 기질 및 성격 특성의 관계

이정현,김옥주,남윤영,신정하,이희봉,김지애,심민영,Lee, Junghyun H.,Kim, Ok Joo,Nam, Yoon-Young,Shin, Jungha,Lee, Heebong,Kim, Jiae,Sim, Minyoung 대한불안의학회 2015 대한불안의학회지 Vol.11 No.1

Objective : Police officers are exposed to job-related traumatic events and have a high prevalence of post-traumatic stress disorder (PTSD). This study examined the relationship between PTSD symptoms and dimensions of temperament and character in police officers. Method : Thirty-six police officers participating in a psychological support program were enrolled. All subjects were asked to complete a demographic questionnaire, the Impact of Event Scale-Revised (IES-R), the Temperament and Character Inventory (TCI) and other self-reported symptoms scales. Results : Among all participants (age $40.8{\pm}10.2$, men 94.4%), the rate of 'post-traumatic stress symptoms group' was 47.2%. After controlling for confounding factors, lower self-directedness scores were significantly associated with higher PTSD symptoms (${\beta}=0.6$, p=0.03) in multiple regression analysis. Conclusion : Character traits, especially self-directedness, were associated with the severity of PTSD symptoms severity. These findings may provide useful information regarding personality factors related to PTSD in police officers.

사회복지전담공무원의 외상사건 및 스트레스 대처방식과 외상후스트레스증상 관련성

이정현,김지애,심민영,전경선,오승아,양정일,이영렬,Lee, Junghyun H.,Kim, Jiae,Sim, Minyoung,Jeon, Kyoungsun,Oh, Seunga,Yang, Jungll,Lee, Yunglyul 대한생물정신의학회 2015 생물정신의학 Vol.22 No.2

Objectives Social workers can suffer from occupational stress resulting from dealing with clients, which might lead to metal health problems. We aimed to investigate the association of duty-related traumatic experiences and stress coping strategies with post-traumatic stress symptoms among social workers in public sector. Methods A total of 110 social workers in public sector (men 30.9%, $36.5{\pm}7.6$ yrs) participated in this study. All subjects were evaluated the frequency and the impact of duty-related traumatic events. Additionally, they completed questionnaires including the Impact of Event Scale-Revised for post-traumatic stress symptoms, the Beck Depression Inventory-II for depressive symptoms, the Scale for Suicidal Ideation for suicide symptoms and the Ways of Coping Checklist for stress coping strategies. Results The most frequent traumatic events were "Violent or abusive language from a client" (95.0%) and "Client made a fuss" (94.5%). The most distressing traumatic event was "Seeing a dead body on duty" (7.6 out of 10), which predicted post-traumatic stress symptoms (odds ratio 4.04 ; 95% confidence interval, 1.79-9.11). Among 4 types of stress coping strategies, the emotion-focused coping was positively correlated with post-traumatic stress symptoms after controlling age and sex (${\beta}$ = 0.50, p < 0.001). Conclusions Social workers in public sector showed high level of post-traumatic stress symptoms. Duty-related traumatic events and the emotional-focused coping strategies were associated with the severity of post-traumatic stress symptoms. The modification of stress coping strategies would alleviate post-traumatic stress symptoms in social workers in public sector.

Interagency Operations Advisory Group (IOAG) Service Catalog 에 따른 국제 표준화 및 국내 적용 방안

이정현,박덕종,안상일,Lee, Junghyun,Park, Durkjong,Ahn, Sangil 한국우주과학회 2022 우주기술과 응용 Vol.2 No.2

Space development has been independently performed by space agencies in each country. This causes redundant development for individual function, resulting in waste of space resources. Accordingly, Interagency Operations Advisory Group (IOAG) was established for standardization with mutual agreement between international organizations, and space resources can be used efficiently between space agencies through cross-support. IOAG define Service Catalog#1, #2, and #3, according to the network layer. In this technical paper, the background and main contents of the IOAG Service Catalog, and the application plan for domestic space development will be discussed.

실험계획법을 이용한 예인 음탐기용 음향패키지 형상 연구

이정현,신증호,권오조,김군칠,Lee, JungHyun,Shin, Jeungho,Kwon, Oh-Cho,Kim, Gunchil 한국음향학회 2019 韓國音響學會誌 Vol.38 No.2

본 연구에서는 예인 음탐기용 음향패키지에 대한 수신전압감도 특성을 분석하기 위해 수치해석과 실험계획법을 적용하였다. 수치해석 결과는 초기 설계된 음향패키지의 구조 공진 모드 특성으로 인한 수신전압감도 변화를 보여준다. 수신전압감도 편차를 줄이기 위해 도출된 음향패키지 설계 변수의 영향은 실험계획법을 통해 분석하였다. 수신전압감도 편차는 수중청음기 쉴드캔 두께(t)의 변화에 가장 민감한 것을 확인하였다. 수조시험 결과 실험계획법에 의해 도출된 음향패키지는 수신전압감도 편차가 감소됨을 확인하였다. In this paper, the characteristics of receiving voltage sensitivity about acoustic package in towed array sonar is analyzed through the numerical simulation and design of experiments. Simulation results show that the variation of receiving voltage sensitivity is caused by the structural resonance mode shape on baseline acoustic package. The effect of design parameters of the acoustic package are analyzed through the design of experiments to reduce the deviation of receiving voltage sensitivity. A change of hydrophone shield can thickness (t) is the greatest effect on the deviation of receiving voltage sensitivity. As a result of water tank test, the acoustic package derived from the design of experiments has reduced deviation of receiving voltage sensitivity.

Tolerance analysis and diagnosis modeling of assembly considering welding distortion and patterns

Junghyun Lee(이정현) (사)한국CDE학회 2015 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2015 No.동계

Preliminary Empirical Analyses of Clustering in Block MDPs

Junghyun Lee(이정현),Se-Young Yun(윤세영) 한국정보과학회 2022 한국정보과학회 학술발표논문집 Vol.2022 No.12

스테인리스 파이프를 이용한 그루브 조인트 디자인의 경제적 효과

이정현(Lee, Junghyun),백명기(Baek, Myeongki) 한국전시산업융합연구원 2013 한국과학예술융합학회 Vol.12 No.-

최근 건축 내부의 형태는 대형 및 다양화되고 있는 추세이며, 기계설비 또한 신뢰성 및 안정성을 필요로 하고 있다. 이에, 본 연구에서는 용접 및 그루브 조인트 접합 공법의 내구성과 경제적 효과를 비교 분석하였다. 배관연결 접합 공법 중 스테인리스강을 적용하여 공법의 장단점 및 현장 적용성을 확립하려 한다. 용접 및 그루브 조인트 공법의 내구성(수압시험) 및 경제적 효과(인건 및 자재비)를 통하여 비교 분석한 결과의 타당성을 검증하였다. 배관연결 공법 중 주로 사용되어지는 용접 공법은 공정 시간이 길며, 화재에 대한 위험성이 높다. 반면, 그루브 조인트 공법은 건설현장에서 화재를 최소화 할 수 있으며, 용접 공법에 비해 약 9%를 절감할 수 있는 방법이다. 또한, 유지보수 및 내구성에 매우 높은 경제적 효과를 얻을 수 있다. 이 공법 과정은 전문 기술력이 불필요하므로 건설산업 분야에서 많은 에너지를 절약할 수 있을 것으로 기대된다. The current trend of the form of inner architecture structures is becoming larger and more diversified. Also, construction equipment is emphasized with reliability and stability. This study will analyze and compare the economic effect and the durability in construction methods, such as the welding joint method and the groove joint method. If we adopt the stainless steel of pipe connect construction methods, then we will build up pros and cons of that method and field applicability. Moreover, we will prove the validity in the comparison result by investigating the hydrostatic test (durability) and material and labor cost (economic effect). The tubular connection method that is mainly used is the welding method. However, it takes a long time to process and is a greater risk of fire. On the other hand, the groove joint construction method will minimize the damage caused by fires in the construction area. By comparison with the welding joint method, the groove joint construction method reduces 9% of construction expenses. This will provide a high economic efficiency in maintenance costs as well as a high level of durability. In addition, this construction method doesn"t need any professional skill, so people can save a lot of time spent in various construction industry fields.

직선 기반 SLAM에서 Reference Heading을 이용한 루프결합 방법 및 실험

이정현(Junghyun Lee),장국현(Guoxuan Zhang),서일홍(Il Hong Suh) 대한전기학회 2012 정보 및 제어 심포지엄 논문집 Vol.2012 No.10