Synthesis, Structural Characterization, and Photoluminescence Properties of SiOx Nanowires Prepared Using a Palladium Catalyst

김현우,이종무,윤의준,염근영,황해진,Hyeong Joon Kim,Hyung-Sun Kim,유지범,Jong Woo Lee,이내응,Seung Hyun Shim,Sun Keun Hwang,Sung-Yoon Chung,주영창 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.6

We report the production of SiO$_x$ nanowires by thermal heating of Pd-coated Si substrates. Scanning electron microscope images indicated that the nanowires had diameters in the range of 15 -- 100 nm. X-ray diffraction, selected area electron diffraction, and energy dispersive X-ray analyses revealed that the nanowires were amorphous and comprised of silicon oxide only. Photoluminescence measurements showed that the SiO$_x$ nanowires had an emission band in the blue region. We discuss a possible growth mechanism for the SiO$_x$ nanowires.

소규모 기독교 대학의 서비스러닝 질적사례 연구: 서비스러닝 효과와 학습정서를 중심으로

김현우,이정미,Kim, Hyun Woo,Lee, Jeong Mee 한국기독교교육학회 2022 기독교교육논총 Vol.- No.71

This study tried to explore the ways to operate service learning more effectively by analyzing the educational effects of service learning and changes in learning sentiments that appeared in the service learning operation process established for the realization of the Christian educational philosophy at a small local Christian university. The analysis was conducted using NVivo11, focusing on the reflection journals of students who participated in service learning in the first semester of 2022 at J University. As a result of the study, through service learning, personal competence growth, self-reflection and will to change, self-esteem and self-efficacy, social and civic aspects, social responsibility enhancement, community (community) empathy and awareness of participation, and helping others There were educational effects such as an increase in the breadth of understanding. In addition, learning emotions that appeared in the service learning process included positive emotions such as gratitude, challenge recognition, pride, confidence, and responsibility, and negative emotions such as worry (difficulty), upset, regret, and awkwardness. It is a measure to increase the educational effect based on the learning emotion shown in the service learning process. When operating service learning, the service period at the visiting institution is increased to 6 weeks or more, and based on close interaction and detailed analysis of the educational environment in the planning stage, Suggest to develop and operate a plan. In addition, if you have the opportunity to receive feedback from your professors and colleagues through demonstrations and mock presentations in the classroom before visiting the institution, and finally have the opportunity to visit the institution again after the results of service learning are announced, more quality service learning education will be operated. Based on the results of this study, it is expected that more valuable and meaningful service learning education opportunities will be provided to learners by designing and operating a practical and sophisticated service learning curriculum.

광학활성 동축 이중 원통을 수직하게 비추는 단색 빛의 산란 : II. 수치 계산 결과

김현우,김진승,Kim, Hyun-Woo,Kim, Jin-Seung 한국광학회 2009 한국광학회지 Vol.20 No.6

광학활성 동축 이중층 원통에 수직 입사하는 전자기 파동의 산란을 수치 계산 법을 써서 살펴 보았다. 앞의 논문에서 얻은 해석적인 해를 바탕으로 수치계산 프로그램을 개발했고, 산란광의 밝기와 편광 상태의 각도에 따른 분포를 몇 가지 예에 대해서 계산하였다. 이러한 수치계산 프로그램은 산란광의 밝기와 편광상태의 각분포를 재어 원통의 크기, 구조, 조성을 비파괴적으로 정확히 결정하는데 쓸 수 있다. The scattering of a normally incident monochromatic light by optically active concentric double cylinders is studied by using a numerical method. A numerical code is developed on the basis of the analytical solutions, and the angular distributions of the intensity and the polarization of the scattered light are computed for some specific cases. The numerical code can be used to non-invasively determine the size, structure, and composition of a double cylinder with high accuracy by measuring the angular distribution of the scattered light by an experiment.

Fabrication and annealing effects of SnO2/SiOx nanocables sheathed by the sputtering technique

김현우,Seung Hyun Shim,Jong Woo Lee,Hyo Sung Kim,Mesfin Abayneh Kebede,나한길,양주찬,공명호,이종무 한국물리학회 2010 Current Applied Physics Vol.10 No.1

We reported an approach, in which we have produced the nano-sized crystalline tin oxide (SnO2) particles with rutile structure. SnO2 nanowires were coated with a shell layer of SiOx via a sputtering method. Transmission electron microscopy and elemental mapping investigations revealed that the nanostructures consisted of a crystalline SnO2 core surrounded by an amorphous SiOx sheath. The annealing effects on the core-shell nanowires were investigated, revealing that the outer surface became rougher by the thermal annealing. For core-shell nanowires, a room-temperature PL measurement with a Gaussian fitting showed yellow, blue, and violet light emission bands, with the relative intensity of the yellow band showing an increase after thermal annealing. Possible PL emission mechanisms are discussed. This study reveals that the sputtering is effective for preparing the shell layers of nanocables.

폐경기 증후군의 사회심리적 측면

김현우,Kim, Hyun-Woo 한국정신신체의학회 1996 정신신체의학 Vol.4 No.1

Regarding menopause as a turning point in woman's lift, the author reviewed the psychosocial aspects of menopause. Seeing menstruation as the symbolic meaning of female sexuality, psychoanalysts argue that menopause, the loss of symbolic meaning of female sexuality, may bring a mourning reaction to woman. It is reported that the high ratio of depression does not have a serious relationship with the menopause syndrome, and that depression cannot be viewed as a different symptoms. It is also proved that most women successfully recover themselves from temporary menopause symptom. Research data shows that some women have a negative thought on the meaning of menopause. Others, however, have a positive concept on the meaning of menopause because of the feeling of release and freedom. In sum, the author suggests that psychosocial consideration is very important as much as bilogical consideration in considering the meaning of menopausal syndrome.

고련피 추출물의 항암활성

김현우,강세찬,Kim, Hyun-Woo,Kang, Se-Chan 한국자원식물학회 2009 한국자원식물학회지 Vol.22 No.4

In the present study, the anti-cancer activity of 80% ethanol extracts from 120 kinds of medicinal herbs and native plants were investigated. Among them, the barks of Melia azedarach L. var. japonica Makino showed the highest cytotoxicity in HCT-15 human colon cancer cell. With this result, we carried out hollow fiber (HF) assay and anti-metastasis study to confirm the anti-cancer effects of M. azedarach var. japonica. In MTT assay, M. azedarach var. japonica.inhibited the proliferation of HCT-15 cells in dose-dependent manner. HF assay was carried out using A549 human adenocarcinoma cell, HCT-15 and SK-Hep1 human liver cancer cell via intraperitoneal (IP) and subcutaneous (SC) site. As a results, SK-Hep1 implanted in IP site showed the highest cytotoxicity. The result from metastatic model using B16/BL6 mouse corresponded to that of HF assay. These results suggest that the ethanol extract from M. azedarach var. japonica. might have a potent anti-cancer activity and advanced study is needed for the development of novel natural anti-cancer drug.

신체형 동통장애 환자의 정신치료 경험

김현우,이현제,Kim, Hyun-Woo,Lee, Hyun-Je 한국정신신체의학회 1994 정신신체의학 Vol.2 No.1

The authors tried to look into the process of the individual psychotherapeutic experience of a 18-year-old male diagnosed as somatoform pain disorder or chronic pain syndrome. The patient had showed strong resistance to acceptance of his psychological problems. Some issues such as indications of psychotherapy for chronic pain, changing the mode of the treatment some problems around changing the therapist secondary gain and parents' attitude were discussed considering their relatedness to the outcome. The psychotherapy had lasted about 2 years and the result was estimated as fair.

유기질비료의 표층 및 전층시비에 따른 벼 수량 변화

김현우,최현석,김병호,김홍재,최경주,정덕영,이연,박광래,정석규,Kim, Hyun-Woo,Choi, Hyun-Sug,Kim, Byeong-Ho,Kim, Hong-Jae,Choi, Kyeong-Ju,Chung, Doug-Young,Lee, Youn,Park, Kwang-Lai,Jung, Seok-Kyu 한국유기농업학회 2012 韓國有機農業學會誌 Vol.20 No.1

벼 유기재배를 하는데 있어서 전층과 표층 시비방법에 따른 토양의 화학성, 물리성, 미생물상, 그리고 벼의 생육과 수량에 대해서 어떠한 영향을 미치는 지를 구명하기 위해서 수행하였다. 2008년부터 2010년까지 3년간에 걸쳐서 전라남도농업기술원 시험포장(논, 양토)에서 조사하였고 시험품종은 '동진1호'를 이용하였다. 토양유기물은 표층시비에서 높았고 토양양이온은 전층시비에서 높았다. 유기질비료의 질소 무기화율은 표층시비에서 높았고 잔존하는 시기별 토양 유기물함량도 표층시비에서 높은 경향을 나타내었다. 토양물리성은 전층시비에 의해서 향상되는 경향을 보였고, 토양 미생물상은 전체적으로 표층시비에서 높았다. 표층시비구가 전층시비보다 5%의 수량이 증수되는 특성을 보였다. This study was investigated to evaluate the effects of fertilizer application of surface and broadcast for rice culture on the soil chemical, physical, and microbial properties as well as growth and yield of rice. The application was made with 'Dongjin 1' rice at Jeollanam-do Agricultural Research & Extension Services from 2008 to 2010. Soil organic matter and cation concentrations were increased by surface and broadcast applications, respectively. Plots treated by surface application tended to be higher seasonal N-mineralization rate in the organic fertilizer and seasonal soil organic matter than those of broadcast application. Soil physical properties seemed to be improved by the broadcast application, and soil microbial properties were increased by the surface application. Surface application increased 5% of rice yield compared to that of broadcast.

얼굴의 특이점 검출 및 실시간 추적을 이용한 e-Book 제어

김현우,박주용,이정직,윤영로,Kim, Hyun-Woo,Park, Joo-Yong,Lee, Jeong-Jick,Yoon, Young-Ro 대한의용생체공학회 2014 의공학회지 Vol.35 No.2

This study is about e-Book program based on human-computer interaction(HCI) system for physically handicapped person. By acquiring background knowledge of HCI, we know that if we use vision-based interface we can replace current computer input devices by extracting any characteristic point and tracing it. We decided betweeneyes as a characteristic point by analyzing facial input image using webcam. But because of three-dimensional structure of glasses, the person who is wearing glasses wasn't suitable for tracing between-eyes. So we changed characteristic point to the bridge of the nose after detecting between-eyes. By using this technique, we could trace rotation of head in real-time regardless of glasses. To test this program's usefulness, we conducted an experiment to analyze the test result on actual application. Consequently, we got 96.5% rate of success for controlling e-Book under proper condition by analyzing the test result of 20 subjects.

광학활성 동축 이중 원통을 수직하게 비추는 단색 빛의 산란 : I. 해석적 이론

김현우,김진승,Kim, Hyun-Woo,Kim, Jin-Seung 한국광학회 2009 한국광학회지 Vol.20 No.6

광학활성 동축 이중 원통의 산란 문제에 대한 해석적인 해를 구하였다. 얻은 해의 타당성을 점검하고자 해를 이미 알고 있는 특수한 경우와 비교하였다. 이 해는 둥근 막대모양의 생물 세포를 광학적으로 분석하는데 쓸 수 있는데, 세포핵에는 나선형으로 꼬인 염색체가 들어 있으므로 광학활성이 있을 수 있다. An analytic solution is obtained for the problem of monochromatic light scattering by optically active, concentric double cylinders. The validity of the obtained solution is indirectly checked by comparing it with solutions already reported for some special cases. The solution can be used in the optical analysis of rod-shaped biological cells which possibly have optically active nuclei containing helically wound chromosomes.