대전시 일부 지하상가 공기중 포름알데히드 농도 및 종사자들의 자각증상에 관한 연구

양태웅,장성실 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

This study was performed to get the fundamental data establishing environmental formaldehyde threshold limit as well as to contribute the health promotion of merchants and customers in two underground shopping-centers in Taejon from Dec. 1997 to Jan. 1998. Formaldehyde concentration and three climate factors-air current, humidity, and temperature-were measured at exit., hallway and inside shops in underground environment, and questionnaire about 15 subjective symptoms among 120 merchants in the inside shops were also surveyed by means of the questionnaire for screening workers exposed formaldehyde in Korea. The results were as follows ; 1. The average formaldehyde concentration in whole area was 0.0299 ppm ; Exit, Hallway and Inside shop were 0.0205 ppm, 0.0325 ppm and 0.0366 ppm, respectively(p<0.000). 2. According to simple regresson analysis, air current(r=-0.2517, p<0.05) and temperature(r=0. 5871, p<0.001) were significantly related to formaldehyde concentration. 3. More than 80% of the merchants have 5 subjective symptoms such as easy fatigahility, headache, throat discomfort, conjunctival injection, and nasal congestion. With all above the results, it can be suggested that environmental formaldehyde threshold limit at underground in Korea be reestablished, regarding related climate factor-air current and temperature-, and the questionnaire for screening subjective symptoms should be developed again for evaluating the evironmental effect of formaldehyde.

Al-Zn-Mg-Cu-Zr 합금의 집합조직 발달과 기계적 특성에 미치는 Sc 첨가의 영향

제창웅,진승준,정동석,임성택,이용연,박노진 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.10

The texture and mechanical properties during fabrication processes - extrusion, cold rolling and aging treatment - of plate in the 7050 Al alloys without/with 0.1%Sc were investigated. In both the cross section(CS) and longitudinal section(LS) of the specimen without Sc, after cold rolling, texture of R-fiber was predominant. In the Sc added alloy after cold rolling, {112}<111>(Cu)+weak (123)<634>(S) texture components developed in the CS of the specimen while strong (3-fiber+(110)<001>(Goss) components developed in the LS of the specimen. After solution treatment and aging treatment, the alloy (CS and LS) without Sc had random texture, but by the alloys with the 0.1%Sc, the components of the rolling texture are not changed. After the aging treatment, hardness and tensile strength of the alloy with 0.1%Sc increased about 15% and 17%, respectively, than those without Sc. Tensile strength of the Sc added specimen was the highest along the rolling direction where the <111> texture was strongly developed. On the other hand, in the specimen without Sc, the mechanical properties were not dependent on the direction of the sample. (Received May 3, 2004)

국가 대표급과 제주도 고교 대표급 수영선수들의 그랩 스타트의 운동학적 분석

김철원,김승곤,오만원,임상용,김성찬,이창준,남사웅,이세형,류재청,신석종,김세민 濟州大學敎 體育科學硏究所 1998 체육과학연구 Vol.4 No.-

The purpose of the study was to undertaken to analysis the Grab starting technique between national representive team(3) and Cheju's representive team(3) with 3D cinematography. The conclusions obtained were as follows: Cheju's showed more elapsed time than national representive team on starting block. and more vertical than horizontal direction of COG position, more concentrated vertical velocity & acceleration than forward direction. Therefore It is necessory for cheju's to train balanced trust force in horizontal and vertical direction in grab starting technique.

전기장 인가에 따른 DNA 신장에 관한 AFM 연구

박진영,한성웅,손세영,송성훈,김종민,Ohtani, Toshio,Muramatsu, Hiroshi,장상목 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.1

본 연구에서는 마이카 표면상에서 전기장에 의한 극히 낮은 농도의 DNA 신장에 대한 효율적인 방법론을 제시하였다. 전기장에 의한 DNA 신장을 AFM형상으로 분석한 결과, DNA 농도범위가 약 57×10 exp(-3)ng/mL-57×10 exp(-6)ng/mL일 때 매우 잘 적용되며, 신장된 DNA는 두 전극 중앙에 존재하였다. 또한, 일반 마이카, Mg^2+ 처리된 마이카, 그리고 AP-마이카 표면들에 대한 신장 효율의 차를 기술하였다. 동일한 실험조건 하에서 AP-마이카의 표면이 가장 좋은 효율의 DNA 신장 결과를 나타내었다. An effective method of DNA stretching using electric field on mica surface was proposed for extremely low solution concentration of DNA. DNA stretching based on electric field was observed by AFM and well applied on the concentration range from 57×10 exp(-3)ng/mL to 57×10 exp(-6)ng/mL. Stretched DNA existed in the middle of two electrodes. The difference in stretching efficiency for the different surfaces of bare mica, Mg^2+ soaked mica and AP-mica was discussed. The best performance of stretching was found from the surface of AP-mica under the same experimental condition.

분류된 학습률을 가진 고속 경쟁 학습

김창욱,조성원,이충웅,Kim, Chang-Wook,Cho, Seong-Won,Lee, Choong-Woong 대한전자공학회 1994 전자공학회논문지-B Vol.b31 No.11

This paper deals with fast competitive learning using classified learning rates. The basic idea of the proposed method is to assign a classified learning rate to each weight vector. The weight vector associated with an output node is updated using its own learning rate. Each learning rate is changed only when its corresponding output node wins the competition, and the learning rates of the losing nodes are not changed. The experimental results obtained with image vector quantization show that the proposed method learns more rapidly and yields better quality that conventional competitive learning. 본 논문은 분류된 학습률을 이용한 고속 경쟁 학습에 대한 연구이다. 이연구의 기본 개념은 각 출력 노우드의 연결강도 벡터에 분류된 학습률을 할당하는 것이다. 출력 노우드의 각 연결강도 벡터는 자기 자신의 학습률에 의하여 갱신된다. 각 학습률은 관련되는 출력 노우드가 경쟁에서 승리할 때에만 변화되며, 승리하지 못한 노우드들의 학습률은 변화되지 않는다. 영상 벡터 양자화에 대하여 실험한 결과는 제안한 방법이 기존 경쟁 학습 방법에 비하여 더 빠르게 학습되고 더 좋은 화질을 갖게 됨을 보였다.

제주 우수 육상경기 선수들의 년중 훈련효과 분석 및 처방

김철원,임상용,김승곤,오만원,김성찬,이창준,남사웅,이세형,류재청 濟州大學敎 體育科學硏究所 1996 체육과학연구 Vol.2 No.-

The study was undertaken to analysis, evaluate, and prescribe t h e annual effect of training of periodically anaerobic and aerobic motor ability for Che-Ju representive team of elementary, middle and high school athletes. first. the performance can be obtained when it was prescribed proper training after analysis of physical fitness by each events. second, individually fitness. scientific analysis. prescription. proper management of athlete will be necessary to apply. In addition to physiology aspect, it is essential to consider sport biomechanics. sport psychology when we prescribe specific events and necessary approach in demension coach-athlete-researcher for individual.

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

제주 우수 수영 선수들의 년중 훈련효과 분석 및 처방

김철원,임상용,김승곤,오만원,김성찬,이창준,남사웅,이세형,류재청 濟州大學敎 體育科學硏究所 1996 체육과학연구 Vol.2 No.-

The study was undertaken to analysis, evaluate, and prescribe the annual effect of training of periodically anaerobic and erobic motor ability for Che-Ju representive team of elementary, middle and high school athletes, first the performance can be obtained when it was prescribed proper training after analysis of physical fitness by each events, second individually fitness scientific analysis. prescription. proper management of athlete will be necessary to apply.

Subcortical Ischemic Change as a Predictor of Driving Cessation in the Elderly

Mi Jang,Chang Hyung Hong,Hyun-Chung Kim,Seong Hye Choi,Sang Won Seo,Seong Yoon Kim,Duk L. Na,Yunhwan Lee,Ki Jung Chang,Hyun Woong Roh,Sang Joon Son 대한신경정신의학회 2018 PSYCHIATRY INVESTIGATION Vol.15 No.12

Objective Motor, perceptual, and cognitive functions are known to affect driving competence. Subcortical ischemic changes on brain magnetic resonance imaging (MRI) can reflect reduction in cognitive and motor performance. However, few studies have reported the relationship between subcortical ischemic changes and driving competence of the elderly. Thus, the objective of this study was to investigate the association between subcortical ischemic changes on MRI and driving abilities of the elderly. Methods Participants (n=540) were drawn from a nationwide, multicenter, hospital-based, longitudinal cohort. Each participant underwent MRI scan and interview for driving capacity categorized into ‘now driving’ and ‘driving cessation (driven before, not driving now)’. Participants were divided into three groups (mild, n=389; moderate, n=116; and severe, n=35) depending on the degree of white matter hyperintensity (WMH) on MRI at baseline. Driving status was evaluated at follow-up. Statistical analyses were conducted using χ2 test, analysis of variance (ANOVA), structured equation model (SEM), and generalized estimating equation (GEE). Results In SEM, greater baseline degree of WMH was directly associated with driving cessation regardless of cognitive or motor dysfunction (β=-0.110, p<0.001). In GEE models after controlling for age, sex, education, cognitive, and motor dysfunction, more severe change in the degree of WMH was associated with faster change from ‘now driving’ state to ‘driving cessation’ state over time in the elderly (β=-0.508, p<0.001). Conclusion In both cross-sectional and longitudinal results, the degree of subcortical ischemic change on MRI might predict driving cessation in the elderly.