대기내 발생하는 복잡한 광화학반응에 대한 수치실험

원경미,김유근,이화운,김희정 한국환경과학회 2006 한국환경과학회지 Vol.15 No.3

Validation of anatomical and biological definition of borderline resectable cancer according to the 2017 international consensus for survival in patients with resectable and borderline resectable pancreatic ductal adenocarcinoma undergoing upfront surgery

Boram Lee,Yoo-Seok Yoon,Jun Suh Lee,Haw Won Lee,Jai Young Cho,Ho-Seong Han 대한종양외과학회 2022 대한임상종양학회 학술대회지 Vol.2022 No.2

AT급전방식 비절연보호선 전류해석에 따른 터널내 가선방식 정립

이해원(Haw-Won Lee),박민주(Min-Ju Park),유향복(Hyang-Bok Ryoo),최장영(Jang-Yong Choi) 한국철도학회 2014 한국철도학회 학술발표대회논문집 Vol.2014 No.10

전기철도의 단권변압기(AT) 급전방식에서 비절연보호선(FPW)은 급전선과 전차선의 중성점으로부터 연결하여 가선하고 있다. FPW 는 전기철도 귀선회로를 구성하면서 전철주 및 완금, 철구조물에 연접하여 가선하고 섬락사고시 금속회로 구성으로 신속한 고장회로 차단이 가능하도록 하며, 계통의 사고시 고장전류의 흐름을 부담하는 기능을 가지고 있다. 또한 설치 위치에 따라 통신유도장해를 경감할 수 있도록 차폐 역할을 하고 있다. 가선방식은 토공구간에서 선로 좌,우측에 가선하며 터널내에서는 선로 중앙부 하수강구조물 등에 연접가선하며, 선로별 상,하선 각 1 회선을 설계하고 있다. 본 논문에서는 FPW 의 전류흐름을 해석하여 역할을 재검토하고, 터널 형태별 장주도에 따라 섬락보호지선(FPGW)과의 조합구성 방식을 검토하여 대안을 제시하였다. One of the electric railway, Auto-Transformers(AT) from Fault Protection Wire(FPW) from feeder lines and contect wire of catenary that connect the overhead line. The orbiting FPW Electric Railway ear to configure, train, and a little slower, iron structure with a rock island and leisure accident metal circuit configuration, the rapid failure circuit block is possible, which would allow strain of the accident of electric current flow breaks down the ability to pay. Based on the location of the installation also encourage communication stumbling blocks to reduce the car to shut down. The KLC track on the left, and on the right track is good, and my tunnel lined up along the track to the steel water and fold in the good, and track stars, each 1 lines ship design. In this paper the current flow FPW role to review and interpret the tunnel, according to the mounting diagram, led by Fault Protection Ground Wire (FPGW) configuration in the combination, review alternatives to do them.

Treatment of melasma by a relatively higher fluence Q-switched 1,064-nm Nd:YAG laser: Long term follow up

( Kwang Hee Won ),( Hyung Min Lee ),( Seung Suk Han ),( Youn Jin Kim ),( Jung Ran Choi ),( Sik Haw ),( Hana Bak ),( Chong Hyun Won ),( Mi Woo Lee ),( Jee Ho Choi ),( Sung Eun Chang ) 대한피부과학회 2012 대한피부과학회 학술발표대회집 Vol.64 No.3

Case Reports : Acral Angioosteoma Cutis

( Eun Ju Lee ),( Jong Ho Lee ),( Min Kyung Shin ),( Sung Won Lee ),( Choong Rim Haw ) 대한피부과학회 2011 Annals of Dermatology Vol.23 No.1S

Acral angioosteoma cutis is a rare disease first described in 2006 that is characterized by vascular proliferation with ossification at the acral area, and which bears clinical similarity to pyogenic granuloma. However, there is no lobular pattern in the capillary proliferation that is a typical histopathological feature in pyogenic granuloma. Metaplastic cutaneous ossification is associated with multiple skin diseases and inflammatory conditions such as scars, nevi, basal cell carcinomas, pilomatricomas, chondroid syringomas, and venous stasis. It is rarely associated with vascular proliferation diseases like hemangiomas and pyogenic granulomas. We report a case of capillary proliferation with ectopic bone formation in a 43-year-old female who presented with an ulcerative, dome-shaped subungual nodule on the left fourth toe, which appeared to be a pyogenic granuloma. Because the biopsy findings showed no lobular capillary proliferation, we determined that this case was consistent with acral angioosteoma cutis. (Ann Dermatol 23(S1) S105~ S107, 2011)

Trends in recent waterborne and foodborne disease outbreaks in South Korea, 2015–2019

Sang Hyuk Lee,Jae-Won Yun,Ji Hee Lee,Yeon Haw Jung,Dong Han Lee 질병관리본부 2021 Osong Public Health and Research Persptectives Vol.12 No.2

Objectives: This study analyzed trends in foodborne and waterborne diseases in South Korea between 2015 and 2019. Methods: The data consisted of information on outbreaks of waterborne and foodborne infectious diseases reported through the Korea Centers for Disease Control and Prevention (KCDC) system. We analyzed the trends and epidemiological aspects of outbreaks by month, place of occurrence, and causative pathogens in this observational study. Results: The number of outbreaks has steadily increased over the last 5 years, but the number of cases per outbreak has followed a decreasing trend. Incidence at daycare centers and preschools has been steadily increasing over consecutive years. Conclusion: The steady number of patients and decreasing number of cases per outbreak, even as the number of outbreaks has been increasing, suggest that the KCDC’s professional management system is operating effectively. It is necessary to continue improving the objectivity and efficiency of the management system and to carefully examine the increasing number of outbreaks in smaller-scale group catering facilities, such as daycare centers and preschools. Outbreaks can be prevented by closely examining those caused by unidentified pathogens and group outbreaks caused by other diseases, identifying problems, and supplementing the management system.

Vibration analysis of scanning thermal microscope probe nanomachining using Timoshenko beam theory

Haw-Long Lee,Shao-Shu Chu,Win-Jin Chang 한국물리학회 2010 Current Applied Physics Vol.10 No.2

In this paper, the effect of thermal vibration on the resonant frequency of transverse vibration of scanning thermal microscope (SThM) cantilever probe is analyzed using the Timoshenko beam theory, including the effects of rotary inertia and shear deformation. The thermal vibration effect can be considered as an axial force and is dependent of temperature distribution of the probe. In this analysis, the temperature is assumed to be distributed in accordance with the constant, linear, and quadratic models along the probe length. The Rayleigh–Ritz method is used to solve the vibration problem of the probe. The numerical results show that the frequency obtained with the constant model is the highest, while it is the lowest for the quadratic model. The frequency of vibration modes of the probe increases with increasing the temperature of the probe. As the ratio of probe length to its thickness increases, the frequency of vibration modes decreases. In addition, the effects of rotary inertia and shear deformation on the frequency are significant, especially in higher order modes and smaller values of the ratio of the probe length to its thickness.

FREE ASYMMETRIC TRANSVERSE VIBRATION OF CIRCULAR MONOLAYER GRAPHENE

Win-Jin Chang,Haw-Long Lee 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.7

The free vibration equations of circular monolayer graphene are analytically derived based onnonlocal elasticity theory. The natural frequency and mode shape for the axisymmetric andasymmetric circular monolayer graphenes are analyzed using the equations. The results showthat the natural frequency of the asymmetric graphene is larger than that of the axisymmetricone. The natural frequency decreases with increasing nonlocal parameter for the axisymmetricand asymmetric graphenes. In addition, the diametrical nodal lines and nodal circles for the°exural vibration of the circular monolayer graphene are investigated. To avoid vibration failureof the sensors, they can be placed at the diametrical nodal lines and nodal circles.

Impact of the COVID-19 Pandemic on the Mental Health of Adolescent Students in Daegu, Korea

Lee Hojun,Noh Yeseul,Seo Ji Young,Park Sang Hee,Kim Myoung Haw,Won Seunghee 대한의학회 2021 Journal of Korean medical science Vol.36 No.46

Background: In February 2020, as coronavirus disease 2019 (COVID-19) spread rapidly in Daegu, South Korea, students in that region experienced many emotional difficulties. In this study, we analyzed the stress and emotional crisis experienced by students during the COVID-19 pandemic, its causative factors, and the factors that affect negative emotions. Methods: We identified the demographic information related to the experiences of unbearable stress and emotional crisis and their causal factors at three points in time: before the pandemic, during its peak, and at the time of the survey (2–3 months after the peak). In addition, we analyzed the factors related to depression and anxiety experienced by students during the COVID-19 pandemic. The Korean version of the Patient Health Questionnaire 9 and the Korean version of the Generalized Anxiety Disorder 7 was used to assess for depressive and anxiety symptoms in the subject students, respectively. Results: A total of 8,177 students participated in the analysis, with 4,072 boys (49.8%), 4,105 girls (50.2%), and 4,463 middle school students (54.6%) and 3,177 high school students (45.4%). The percentage of students who experienced unbearable stress was 9% before the COVID-19 pandemic, increased to 16% at the peak of the COVID-19 pandemic, then decreased to 12.7% at the time of the survey. Stress was experienced more by girls (18.1% versus 13.8% in boys; χ2 = 28.159, P < 0.001) and high school students (19.0% versus 13.5% in middle school students; χ2 = 45.437, P < 0.001). Overall, 7.6% experienced emotional crises during the COVID-19 pandemic, which was more prevalent in girls (10.1% versus 5.2% in boys; χ2 = 71.025, P < 0.001) and in high school students (8.8% versus 6.7% in middle school students; χ2 = 12.996, P < 0.001). Depression and anxiety was seen in 19.8% and 12.3% of students during the COVID-19 pandemic, respectively. The risk factors for depression and anxiety included unbearable stress before the COVID-19 pandemic (P < 0.001), mental health (P = 0.044), and age (P = 0.040), whereas resilience was identified as a protective factor for depression and anxiety (P = 0.001). Conclusion: Students in Daegu experienced lots of mental difficulties since the COVID-19 pandemic. It will be necessary to improve stress management and resilience to improve students' mental health in disasters such as the COVID-19 pandemic.

Vibrational Analysis of a Single-Layered Nanoporous Graphene Membrane

Haw-Long Lee,Win-Jin Chang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.4

In this study, we use the atomic-scale finite element method to investigate the vibrational behavior of the armchair- and zigzag-structured nanoporous graphene layers with simply supported-free-simply supported-free (SFSF) and clamped-free-free-free (CFFF) boundary conditions. The fundamental frequencies computed for the graphene layers without pores are compared with the results of previous studies. We observe very good correspondence of our results with that of the other studies in all the considered cases. For the armchair- and zigzag-structured nanoporous graphenes with SFSF and CFFF boundary conditions, the frequencies decrease with increasing porosity. When the positions of the pores are symmetric with respect to the center of the graphene, the frequency of the zigzag nanoporous graphene is higher than that of the armchair one. To the best of our knowledge, this is first study investigating the relation between the vibrational behavior and porosity of nanoporous graphene layers, which is essential for tuning the material/structural design and exploring new applications for nanoporous graphenes.