성장기 아동에서 Cervical Headger 사용시 골격적 변화 양상에 대한 연구

현하영,이진우,차경석 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.5

성장기 아동의 Class II 부정교합에서 과도한 성장의 억제, 미약한 성장의 촉진으로 성장 시기에 적절히 치료하는 것이 가장 효과적이며 좋은 치료 방법이다. 이러한 방법 중 가장 적절히 쓰이는 장치 중 Cervical headgear의 사용을 들수 있으며 악골에 효과적으로 적용된다. 그러나 장치의 부작용이라 할 수 있는 수직적 성장의 과잉을 볼 수 있는데 이에 대해 많은 서학들의 연구가 시행되어 왔다. 본 연구는 Cervial headgear의 상하악골에 대한 효과를 분석하고 Lower facial height를 기준으로 증가군(>0)과 증가하지 않은 군 ( ≤0)으로 나누어 골격적 특성을 알아보기 위해 단국대학교 부속 치과병원에 내원한 성장기 아동의 II급 부정교합환자 25명을 대상으로 cervical headgear를 사용한 결과 다음과 같이 다소의 지견을 얻었기에 보고하는 바이다. 1. 상악골의 전방 성분이 억제되었고, 구개 평면의 전방이 하방으로 tipping되었으며 상악 제 1대구치의 후방 이동이 있었다. 2. 하악골의 두개저에 대한 상대적인 전방 이동이 있었으며 상악에 대한 하악 제1대구치의 상대적인 전방 이동이 있었고 하악골의 alveolar growth에 의한 수직적인 증가가 있었다. 3. 전안면 고경과 후안면 고경이 각기 유의하게 증가했으나 안면 고경 비율에는 유의성이 없었다. 4. Lower facial height가 증가한 group이 증가하지 않은 group보다 ramus의 길이가 짧고 palatal plane angle이 더 작았으며 상악 제 1대구치의 후방 이동량이 더 많았다. This study was to investigate the horizontal & vertical bone change pattern when using cervical headgear in Class II malocclusion of growing children and compared the skeletal features between the group with increased lower facial height and the group without increase in lower facial height. The results are as follows ; 1. Forward growth of maxilla was inhibited, downward tipping of anterior palatal plane could be seen and distal movement of maxillary first molar was observed. 2. There was relative forward movement of Mandible against the Maxillary cranial base, and relative forward movement of mandibular 1st molar against the Maxilla and vertical increase due to alveolar growth of Mandible. 3. There was significant increase in anterior and posterior facial heights but the ratio of facial height showed no significant difference. 4. The group with increased lower facial height has shorter ramus length, than the smaller palatal plane angle, and more distal movement of Maxillary 1st molar than the group without increase Ha-young Hyun.

물리적 외력이 배양중인 치주인대세포에 미치는 영향

김현영,차경석 대한치과교정학회 1994 대한치과교정학회지 Vol.24 No.2

The movement of teeth during orthodontic treatment requires bone remodeling process in periodontal tissue. To find out changes occuring in the cell itself, mechanical force was applied to the cultured periodontal ligament cells. Following results were obtained from measuring the changes in cyclic AMP and PGE₂,³H-thymidine incorporation amount in time lapse after application of mechanical force. 1. When mechanical force was applied to cultured PDL cells, the amount of cAMP in cells were increased significantly after 15 min. of force application, but were decreased gradually as time lapsed. 2. When mechanical force was applied to cultured PDL cells, the amount of PGE2 were increased at 20,40,60 min. and was significantly increased at 20 min. 3. When mechanical force was applied to cultured PDL cells, the amount of ³H- thymidine incorporation was some increased, increased, but not statistically significant.

염화비닐 노출 근로자의 시료채취시기에 따른 요중 thiodiglycolic acid의 농도 변화

김현수,김치년,원종욱,차봉석,이경종,노재훈 大韓産業醫學會 2006 대한직업환경의학회지 Vol.18 No.2

목적: 본 연구는 염화비닐 및 폴리염화비닐수지 제조공장의 VCM 노출 근로자들을 대상으로 소변 시료채취 시기에 따른 요중 TDGA 농도의 변화를 알아보고자 하였다. 방법: VCM 및 PVC 제조공장 남성 근로자 31명을 대상으로 공기중 VCM 개인노출평가를 실시하였으며 소변내 TDGA 배설 양상을 알아보기 위해 3일 휴식 후 척 작업 시작 전(TDGA1), 1일 작업종료 후(TDGA2), 1일 작업 한 다음날 작업 전(TDGA3) 소변을 채취하였다. VCM에 노출되지 않은 대조군 30명에 대해 작업종료 후 소변을 채취하였다. 공기 중 VCM의 측정 및 본석은 NIOSH 공정시험법 No. 1007에 따라 실시하였다. 요중 TDGA 분석을 위하여 소변을 trimethylsilyldiazomethane(2.0 M in diethyl ether)으로 메틸화 반응하여 가스크로마트그래피/펄스불꽃광도검출기로 분석하였다. 결과: VCM 노출 후 요중 TDGA가 배설되어 감소하는 시기를 조사하기위해 대조군과 VCM 노출 근로자들의 3일 휴식 후 작업 시작 전 요중 TDGA 농도 (TDGA1)를 비교한 결과 각각 0.179±0.271 mg/g creatinine, 0.218±0.443 mg/g creatinine으로 통계학적으로 유의한 차이가 없었다. 1일 작업 종료 후 요중 TDGA 농도(TDGA2)는 0.434±0.623 mg/g creatinine, 1일 작업 한 다음날 작업전 요중 TDGA 농도(TDGA3)는 0.767±1.056 mg/g creatinine으로 순차적으로 증가하였다. 하루 노출량을 평가하기 위해 공기 중 VCM 농도와 요중 TDGA와의 단순회귀분석 결과 1일 작업한 다음날 작업 전 요중 TDGA 농도(TDGA3)와 공기 중 VCM 농도와의 관련성은 R^(2)=0.4215로 1일 작업종료 후 요중 TDGA 농도(TDGA2)보다 높았다. 결론: VCM 노출 후 3일이 경과하면 대조군의 요중 TDGA 농도 수준으로 감소하여 요중 TDGA의 배설 반감기가 3일 이내인 것으로 판단된다. 또한, 하루 근무하고 그 다음날 작업 전에 채취한 요중 TDGA 농도(TDGA3)가 전날 근무시의 VCM노출량과 상관성이 가장 높아 하루 동안의 VCM노출을 평가하기 위한 유용한 생물학적 지표로 사용할 수 있을 것으로 판단된다. Objectives: The study was performed to investigate the changes of urinary thiodiglycolic acid (TDGA) concentration in workers exposed to vinyl chloride monomer (VCM) according to the time of sampling urine. Methods: The personal exposure to airborne VCM was assessed and urinary TDGA concentration was sampled in 31 workers employed in a VCM and polyvinyl chloride (PVC) manufacturing factory. Urinary TDGA was sampled three times: before the start of the shift after 3 days off (TDGA 1), after the end of the first-day shift (TDGA2) and before starting the following day shift after completing the one- day shift (TDGA3). Urinary TDGA in 30 workers who had not been exposed to airborne VCM was sam- pled after the end of the shift. A gas chromatography/pulsed flame photometric detector (GC/PFPD) was utilized to analyze TDGA concentration in urine after the urine was methylated with trimethylsilyldia- zomethane (2.0M in diethyl ether). Results: The creatinine level was 0.179±0.271 mg/g in the control workers and 0.218±0.443 mg/g in the workers before the start of the shift after 3 days off (TDGA1), showing no significant difference (p=0.7035). Urine samples were compared according to sampling time in order to investigate the change of urinary TDGA concentration in the case of continuous exposure to airborne VCM. In VCM-exposed workers, urinary creatinine concentration was 0.434±0.623 mg/g in TDGA2 and 0.767±1.056 mg/g in TDGA3, which indicated a gradual but significant increase (p=0.024). In terms of the statistical correlation between airborne VCM and urinary TDGA to evaluate exposure dose per day, of the three urinary TDGA concentrations, TDGA3, showed the highest degree of regression (R^(2)=0.4215) with 8h-TWA airborne VCM concentration. Conclusion: Based on this result, the excretion half-life of urinary TDGA was assumed to be less than 3 days, because the concentration of urinary TDGA at 3 days after exposure to airborne VCM was decreased to the level of urinary TDGA concentration in the control workers. The concentration of urinary TDGA increased in the case of continuous shift, due to the accumulation of residual metabolites of TDGA. It was considered that TDGA3 can be applied as a useful biological index to evaluate the exposure dose of airborne VCM during one day because TDGA3 showed the highest correlation with the exposure dose of airborne VCM in the previous shift day.

구간분할 바이너리 제어를 이용한 로봇핸드의 동특성에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

In recent years, as the robot technology is developed the researches on the artificial muscle actuator that enable robot to move dextrously like biological organ become active. The widely used materials for artificial muscle are the shape memory alloy and the electro active polymer. These actuators have the higher energy density than the electromechanical actuator such as motor. However, there are some drawbacks for actuator. SMA has the hysterical dynamic characteristics. In this paper the segmented binary control for reducing the hysteresis of SMA is proposed and the simulation of anthropomorphic robotic hand is performed using ADAMS.

대전 대덕구 출토 복식 유물에 부착된 세균의 종류 및 섬유소분해효소 활성

이상준,차미선,조현혹,백영미,권영숙 한국의류산업학회 2005 한국의류산업학회지 Vol.7 No.1

This study was aimed to isolation and identification of attached bacteria on the clothes excavated from Deajeon area dating on the 16th century. From the observation with colony shape, 17 bacterial strains were isolated, and then 7 bacterial strains were identified with morphological and biochemical characteristics. Streptococcus sp., Alcah eves faecalis, Gemella sp., Acinetobacter sp., Pseudomones vesicularis, Aeromonas sails. salmonicida, Moraxella spp. In observation of the bacterial strains by the sort of textile, more bacterial strains were found in silk, cotton, and cotton bats than in ramie and hemp. It is suggest that hemp has antibacterial characteristics due to the presence of lignin. In the comparison washed samples with unwashed ones, there were more kinds of bacterial strains in washed samples. In the cellulase activity tests, all isolated bacteria had low level cellulase activity.

초정밀 광소자 정렬 스테이지의 구동 특성에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement to the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

다채널 광정렬 장치에서의 다자유도 회전 스테이지 동작 특성에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

In recent years, as the demands of VBNS(Very high speed Backbone Network Service) and VDSL(Very high-data rate Digital Subscriber Line) increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, WDM elements increase. The alignment and the attachment technology are very important to fabricate the optical elements for communication. In this paper, the mechanism of rotational stage are studied. with the three different method and the results of them are applied to the design of the system. The performance test of resolution and travel is performed.

극초정밀 다축 스테이지의 광소자 정렬에 관한 연구

정상화,차경래,김현욱,최석봉,김광호,박준호 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

In recent years, as the demands of VBNS and VDSL increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM elements increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the optical alignment characteristics of multi-axis ultra precision stage were studied. The alignment algorithms were studied for applying to the ultra precision multi-axis stage. The alignment algorithm is comprised of field search and peak search algorithms. The contour of optical power signals can be obtained by field search and the precise coordinate can be found out by peak search. Two kinds of alignments, such as 1ch. input vs. 1ch. output optical stack, and 1ch. input vs. 8ch. output PLC stacks were performed for investigating the alignment characteristics.

서해 태안반도 연안에서 오터트롤에 채집된 저서생물의 종조성 및 계절변동

정경숙 ( Gyeong Suk Jeong ),차병열 ( Byung Yeul Cha ),임양재 ( Yang Jae Im ),권대현 ( Dae Hyeon Kwon ),황학진 ( Hak Jin Hwang ),조현수 ( Hyun Su Jo ) 한국수산과학회 2014 한국수산과학회지 Vol.47 No.3

To investigate specie composition and seasonal variation of demersal organisms in the coastal waters off the Taean peninsula, otter trawl surveys were conducted from April 2010 to January 2011. A total of 75 species were collected including 44 species of Pisces, 19 species of Crustacea, 6 species of Cephalopoda, 4 species of Gastropoda, and I spe-cies each of Bivalvia and Echinoidea. The dominant species in each season were Palaemon gravieri in spring, Cha-rybdis bimaculata in summer, Loligo japonica in autumn, and Crangon hakodatei in winter. The number of species, individuals and biomass were highest in autumn and lowest in winter. The diversity index was highest in summer and lowest in winter. The dominance index was highest in winter and lowest in summer. The richness index was highest in autumn and lowest in winter. The evenness index was highest in summer and lowest in autumn. A cluster analysis showed that demersal organisms were divided into two groups; spring and winter organisms (Group 1) and summer and autumn organisms (Group 2). We detected a significant difference (P<0.05) between these groups, mainly owing to Platycephalus indicus, Repomucenus koreanus, and Paralichthys olivaceus within Pisces: Trachysalambria curvi-rostris, Metapenaeopsis dalei, P. gravieri and C. hakodatei within Crustacea: and L. japonica within Cephalopoda.

남자 고등학교 세팍타크로 경기의 공격기술에 관한 분석 연구

김영호,고문석,제임스전,이영익,차정훈,현종건,김범수,임종만,이석인 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.6

This research aims at analysis of attack technique in sepaktakraw games. For this purpose, 3 high school coaches observed and recorded each game Five times in videos of high school male players' thirty games in 2003. The conclusion from the analysis of the recorded data are as follows. 1. Scissors spike was the most popular (favorite) attack technique. Rolling spike, tapping spike and heading spike was popular in order. 2. Heading spike showed the highest success rate (73.5%) in attack technique. And tapping spike (69.5%), scissors spike (57.8%) and rolling spike (67.11) showed a lower success rate in order. In failure rate, heading spike (5.5%), tapping spike (36.5%), scissors spike (32.2%) and rolling spike (32.9%) had a higher percentage in order. 3. When receive was stable, the success rate in attach technique was 47.1%, the failure rate was 20.1%. On the other hand, when receive was unstable, the success rate in attach technique was 16.5%, the failure rate was 14.3%.