의학전문대학원 학생들의 수면과 심리적 요인

김대욱,김성곤,김지훈,양영희,정우영,이진성,Kim, Dae-Wook,Kim, Sung-Gon,Kim, Ji-Hoon,Yang, Young-Hui,Jung, Woo-Young,Lee, Jin-Seong 대한수면의학회 2013 수면·정신생리 Vol.20 No.2

목 적 : 의학전문대학원 학생들은 과도한 학업으로 인해 수면 시간이 부족하고 수면의 질이 낮다고 알려져 있다. 본 연구는 의학전문대학원 학생의 수면 양상 및 이와 연관이 있을 것으로 생각되는 심리적 문제를 조사하였다. 방 법 : 부산대학교 의학전문대학원 1~4학년 학생 352명을 대상으로 수면 양상, Pittsburgh sleep quality index(PSQI), Epworth sleepiness scale(ESS), global assessment of recent stress scale(GASS), the center for epidemiologic studies-depression scale(CES-D), and Moudsley obsessive-compulsive inventory(MOCI)를 조사하였다. 두 군간 연속변수 비교에는 독립 t-검정, 비연속비교는 ${\chi}^2$-검정, 두 변수간의 상관관계는 Pearson 상관분석, 그리고 세 군 이상 비교에는 ANOVA를 이용하였다(p<0.05, 양측검정). 결 과 : 평일 수면시간 5시간 36분, 주말 수면시간 7시간 39분으로, 주말 수면시간이 더 길었다(t=15.94, p<0.001). 취침 시각은 평일 0 : 49, 주말 1 : 34으로 주말에 더 늦게 취침하였고(t=-5.23, p<0.001), 기상 시각은 평일 6 : 58,. 주말 9 : 30으로 주말에 더 늦게 기상하였다(t=-24.48, p<0.001). PSQI는 ESS(r=0.383, p<0.001), GASS(r=0.326, p<0.001), CES-D(r=0.393, p<0.001), 그리고 MOCI 점수(r=0.247, p< 0.001)와 양의 상관관계를 보였지만, 성적과는 상관관계를 보이지 않았다(r=0.072, p=0.228). 학년이 높을수록 PSQI, GASS, CES-D, MOCI 점수가 낮았다(p<0.05). 결 론 : 의학전문대학원생들의 수면의 질은 낮았고 수면 시간은 부족하였다. 수면의 질은 주간졸림, 우울감, 스트레스, 강박 성향과 연관성이 있었다. Introduction: Although it is well known that medical students are not getting an adequate amount of sleep, there have been only a few studies on the sleep patterns of medical students and the related factors. Therefore, the present study aimed to investigate the medical students' sleep patterns and the related factors. Methods: A questionnaire package was administered to the $1^{st}$ to $4^{th}$ year medical students at one medical school. It consisted of questions asking about their lifestyles as well as Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale (ESS), global assessment of recent stress scale (GASS), the center for epidemiologic studies-depression scale (CES-D), and Moudsley obsessive-compulsive inventory (MOCI). A total of 352 students (206 males and 146 females) responded to the survey and the result was analyzed using the independent t-test, the chi-square test, the paired t-test, Pearson's correlation and ANOVA. p-values of less than 0.05 were considered statistically significant in analyses. Results: The weekend bedtime was significantly delayed (0 : 49 on weekday ; 1 : 34 on weekend ; t=-5.23, p<0.001), the weekend rise time was delayed (6 : 58 on weekday ; 9 : 30 on weekend ; t=-24.48, p<0.001) and the total sleep time was increased on weekends (5 : 36 on weekday ; 7 : 39 on weekend ; t=15.94, p<0.001). The PSQI score of all subjects was 6.43{\pm}2.64. PSQI was positively correlated with ESS (r=0.383, p<0.001), GASS (r=0.326, p<0.001), CES-D (r=0.393, p< 0.001), and MOCI (r=0.247, p<0.001), but not with GPA (r=0.072, p=0.228. The more senior students had lower PSQI, GASS, CES-D, and MOCI score (p<0.05). Conclusion: Medical students were experiencing a lack of sleep during weekdays as they have a later bedtime and earlier rise time, and consequently had more hours of sleep on weekends. Overall, the medical students were experiencing poor sleep quality and sleep deprivation. Poor sleep quality is associated with psychological problems (daytime sleepiness, stress, depression, and obsessive tendency).

플라즈마 침탄 공정을 이용한 SCM415강의 표면 경화 특성

김대욱,김동원,임병수,김석범,Kim, Dae-Wook,Kim, Dong-Won,Lim, Byeong-Soo,Kim, Seuk-Buom 한국재료학회 1998 한국재료학회지 Vol.8 No.8

현재 자동차용 소재 및 기계부품에 폭넓게 이용되는 SCM415강의 플라즈마 침탄 특성을 연구하기 위해 가스조성, 압력, 전류밀도, 온도 및 시간을 변수로 사용하였다. 가스조성의 경우 저합금강에서는 수소 가스 효과보다 메탄가스에 의해 주로 침탄특성이 좌우되며 메탄가스 100%일 때 시편 내의 모든 방향에서 경화층 분포가 일정하고, 최대의 유효경화깊이를 얻을 수 있었다. 가스압력이나 플라즈마 전압이 상승할 때 전류밀도가 상승하게 되는데, 이에 따라 최표면의 탄소농도가 증가되어 강의 유효경화깊이는 증대되었다. 침탄 온도일 경우 적어도 85$0^{\circ}C$이상되어야 유효경화깊이를 얻을 수 있었고, 온도가 상승할수록 유효경화깊이의 증가를 나타내어 침탄 효과가 우수하였다. 탄소의 확산 깊이는 침탄 시간의 제곱근에 비례하는 것으로 나타났다. 플라즈마 치탄한 강의 피로강도를 평가한 결과 열처리하지 않은 시편이나 재가열처리한 시편에 비해 높은 피로강도를 나타내었다. The influence of plasma carburizing process on the surface hardness of SCM415 low-alloy steel (0.15% C) was investigated under the various process conditions of gas composition. gas pressure, plasma current density. temperature and time. The effective case depth was found to depend on the amount of methan gas containing carbon. thus the deepest case depth and the uniform hardeness were obtained with the 100% methan gas. The case depth increased with the plasma current density. The effective plasma carburizing temperature of SCM415 steel was found to be higher than 85$0^{\circ}C$, and the case depth was proportional to the square root of carburizing time under the same current density. The bending fatigue strength of the plasma carburized specimen is' higher than those of as- received specimen or reheat-quenched specimen.

The Effects of Ownership, Regulation and Marked Structure on the Pricing: Evidence from the U.S. Electricity and Natural Gas Industries

김대욱,Kim, Dae-Wook 한국환경경제학회 2008 자원·환경경제연구 Vol.17 No.4

본 논문은 미국의 전력산업과 천연가스산업이 본격적인 구조변화를 시작한 1999년부터 2001년까지의 자료를 사용하여 제도적인 변화가 시장가격에 미친 영향을 분석한다. 이를 위해 가격에 영향을 미치는 비용과 수요를 제어한 축약형태(reduced forms) 모형의 회귀분석을 사용하여, 본 논문은 제도적인 요소 중에서 구체적으로 어떠한 요소가 가격결정과 긴밀히 연결되어 있는지를 추정한다. 분석결과에 의하면 투자자 소유의 기업의 전력가격이 공기업에 비해서 보다 높은 것으로 추정되었다. 더불어 전기와 천연가스 2개의 상품을 공급하는 기업은 1개의 재화를 제공하는 기업에 비해서 두 재화를 보다 저렴한 가격으로 공급하는 규모의 경제를 가지고 있는 것으로 나타났다. 마지막으로 천연가스 기업간의 합병은 합병이 일어나지 않은 지역에 비해서 가스요금의 수준이 보다 높은 것으로 나타났다. In this paper, we examine the institutional prices differences in the electricity and natural gas industries using unbalanced panel data from 1999 to 2001. The changing market structures following deregulation in both markets allow us to examine the institutional prices differences by ownership type, market structure and merger activities. Estimating the reduced form, after controlling both intrinsic characteristic (marginal costs) and external factors (demand), allows us to identify the extent to which specific factors are correlated with the price. Furthermore it allows us to identify systematic institutional price differences in both electricity and natural gas markets. Our estimation results suggest that the private firms in electricity markets are associated with higher prices than public firms after controlling for demand and cost. We further find that dual-product firms in the natural gas industry and the electricity industry are associated with lower rates than single product firms. These results provide a weak evidence of economies of scope in the dual-product firms. Our results finally suggest that merger activities in natural gas markets are associated with higher rates.

만성 외측 발목 불안정

김대욱,성기선,Kim, Dae-Wook,Sung, Ki-Sun 대한족부족관절학회 2018 대한족부족관절학회지 Vol.22 No.2

Chronic lateral ankle instability is a major complication of acute ankle sprains, which can cause discomfort in both daily and sports activity. In addition, it may result in degenerative changes to the ankle joint in the long term. An accurate diagnostic approach and successful treatment plan can be established based on a comprehensive understanding of the concept of functional and mechanical instability. The patients' history and correct physical examination would be the first and most important step. The hindfoot alignment, competence of the lateral ligaments, and proprioceptive function should be evaluated. Additional information can be gathered using standard and stress radiographs. In addition, concomitant pathologic conditions can be investigated by magnetic resonance imaging. Conservative rehabilitation composed of the range of motion, muscle strengthening, and proprioceptive exercise is the main treatment for functional instability and mechanical instability. Regarding the mechanical instability, surgical treatment can be considered for irresponsible patients after a sufficient period of rehabilitation. Anatomic repair (modified $Brostr{\ddot{o}}m$ operation) is regarded as the gold standard procedure. In cases with poor prognostic factors, an anatomical reconstruction or additional procedures can be chosen. For combined intra-articular pathologies, arthroscopic procedures should be conducted, and arthroscopic lateral ligament repair has recently been introduced. Regarding the postoperative management, early functional rehabilitation with short term immobilization is recommended.

KC-100 소형항공기 추진계통 비행시험 사례연구

김대욱,강성수,김찬조,우봉길,Kim, Dae-wook,Kang, Sung-soo,Kim, Chan-jo,Wu, Bong-gil 항공우주시스템공학회 2013 항공우주시스템공학회지 Vol.7 No.2

The conformity of propulsion system need to be evaluated thorough the flight test because it is an important part of the airplane to ensure the flight safety. In the small airplane development, the flight test according to KAS(Korean Airworthiness Standards) Part 23 is one of the ways to verify compliance in terms of satisfactory aircraft/engine/propeller integration. This thesis introduces means of verifying the compliance and test requirement of KAS Part 23 for the conformity of the propulsion system in small airplane. It also describes procedures and methods of propulsion system flight test through KC-100 airplane project.

MF 주파수대역 무선전력전송에서 매칭회로타입에 따른 매칭특성에 대한 연구

김대욱(Dae-Wook Kim),양대기(Dae-Ki Yang),안영오(Young-Oh An),임은석(Eun-Suk Lim),최상돈(Sang-Don Choi),최대규(Dae-Kyu Choi),정윤도(Yoon-Do Chung) 전력전자학회 2014 전력전자학술대회 논문집 Vol.2014 No.7

스마트폰을 이용한 타이어 측면 정보 인식

김대욱(Dae-wook Kim),감동욱(Dong-uk Kam),유수곤(Soogon Yoo),이건우(Kunwoo Lee) (사)한국CDE학회 2016 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2016 No.동계

Smart application for a novel recognition system of commercial tire was suggested. Consumers who buy their car tire through online usually make wrong order because they hardly have knowledge about interpreting tire information, which is carved on left side of tire. The suggested system only needs smart phone and provides the tire information (maker & model) from the picture taken by consumer’s phone. At first, wheel rim of tire is detected using texture-based segmentation algorithm and rectified image is acquired. After the large text area is cropped, bounding boxes which have large possibility of including text were extracted. Through HOG feature machine learning and convolutional neural network deep learning, tire information can be recognized. With suggested system, consumers can easily understand the tire information only by taking the picture.

조직공정성, 직무만족, 조직몰입, 혁신행동의 구조적 관계 분석 : 지방공무원의 인식을 중심으로

김대욱 ( Kim Dae Wook ),이희재 ( Lee Hee Jae ) 한국지방행정연구원 2016 地方行政硏究 Vol.30 No.3

본 연구는 조직공정성이 혁신행동에 미치는 관계에 있어 내생변수로서 직무만족과 조직몰입을 설정하여 변수 간 구조적 관계를 규명하고자 하였다. 설정된 구조적 관계는 이론과 선행연구로부터 도출된 것으로 확증적 인과관계의 검증이라는 구조방정식의 목적을 효과적으로 달성하는 연구모형이다. 지방공무원을 대상으로 한 설문조사의 결과 측정모형의 신뢰성과 타당성이 입증되었다. 변수 간 관계에 대한 가설검정 결과 조직공정성은 직무만족과 조직몰입에 직접적인 정(+)의 영향을 미치나, 혁신행동에는 직접적 영향이 아닌 간접적 영향을 미친다는 사실을 확인할 수 있었다. 또한 조직몰입은 혁신행동에 직접적인 유의미한 요인이나, 직무만족은 그렇지 않다는 점을 밝혀 양자 간의 차별적 영향력 또한 규명할 수 있었다. 이러한 연구결과를 바탕으로 조직 관리에 대한 이론적 및 실천적 시사점을 제시하였다. This study tries to find the relationship between organizational fairness and innovation activity with endogenous variables; job satisfaction and organizational commitment. This structural relationship came from theory and previous studies. It effectively achieves the goal to verify causal relationships. The reliability and the validity of this model are statistically proven by questionnaire survey targeting local public employees. Statistical hypothesis testing shows that organizational fairness have directly positive effect on job satisfaction and organizational commitment, but indirectly positive effect on innovation activity. Also organizational commitment has direct effect on innovation activity whereas job satisfaction has no significant direct effect on innovation activity. Based on the analysis, this study suggests theoretical and practical directions to effective organization management.

Boom & Receptacle Refueling 시스템 및 공중급유 조종특성 비행시험 소개

김대욱(Dae-wook Kim),김찬조(Chan Jo Kim) 한국항공우주학회 2016 한국항공우주학회 학술발표회 논문집 Vol.2016 No.11

실업팀 씨름선수의 상해에 관한 연구

김대욱 ( Kim Dae Wook ),장인영 ( Jang In Young ),허유섭 ( Huh Yu Sub ) 경남대학교 교육문제연구소 2016 敎育理論과 實踐 Vol.25 No.-

This study investigate on injury inflicted during exercise on employment team ssrreum players who are currently engaged in the spore as of 2016. For data analysis, frequency analysis was carried out in order to identify social demographic characteristic. Through the application of research methods and procedures prescribed above, differences and relations among each variable such as period, time and season, place, Treatment period causes of injury were analyzed. injury period were winter training, training camp, summer training, joint training, and event of a game, the most high in the winter training period. injury time were afternoon, morning, evening and dawn, the most high in the afternoon. injury season were winter, summer, autumn and spring, the most high in the winter. injury places were practice ground, camp ground, school ground, and event ground, the most high in the practice ground. exercise injury treatment and recovery period were in the 4 weeks, 8 weeks, 2 weeks, 6 weeks, 12 weeks, and 3 months, the most high in the 4weeks. exercise injury treatment method were in the oriental medcine clinic, medical care, chiropractic therapy, and one of himself, the most high in the oriental medcine clinic. The Ssirum was a game played by their opponents, the body contact sport injuries in the nature of the events likely to cause. In the case of a higher level of technology becoming major drag on their game because of high frequency of occurrence of injury.