기립균형시 슬관절 전략이 안정성 한계에 미치는 영향

권혁철,정동훈 한국전문물리치료학회 1999 한국전문물리치료학회지 Vol.6 No.3

앉은 자세와 기립 자세의 비율이 정상 성인의 체간 굴곡 유연성에 미치는 영향

권혁철,정동훈 한국전문물리치료학회 2001 한국전문물리치료학회지 Vol.8 No.2

For spinal flexibility measurements to be meaningful to clinicians or researchers, they must have a normative information and an understanding of how different variables affect spinal range of motion (ROM). Normal spinal ROM measurements are influenced to differing degrees by many factors. These factors include age, gender, time of day, leisure activities, previous history of low back pain, warming up, and the techniques with which normative data are collected. The additional variables of standing height, ratio of standing height to sitting height, and obesity had not been previously studied extensively and were shown to have a significant effect on flexibility in the sagittal plane. These relationship cannot be explained easily. Thus, the purpose of this study was to determine the relationship between spinal flexibility and individual factors (weight, standing height, and ratio of standing height to sitting height) that influence it. Fifteen healthy subjects between the ages of 20 and 27 years were studied. Two physical therapists measured independently the spinal forward bending ROM in the sagittal plane by Remodified Schober test and Finger-to-floor test. In order to determine the statistical significance of the result the Pearson's correlation was applied at the .05 level of significance. The results of this study were as follows: 1) Significant relationship was not identified between spinal flexibility and weight. 2) Significant relationship was not identified between spinal flexibility and standing height. 3) Significant relationship was not identified between spinal flexibility and ratio of standing height to sitting height.

가시광선중합화에 따른 충전용 Glass lonomer Cement의 물리적 성질에 관한 연구

권혁춘,신동훈 大韓齒科保存學會 1992 Restorative Dentistry & Endodontics Vol.17 No.2

The aim of this study was to investigate the physical properties of visible light curing Glass Ionomer cement for restorative esthetic filling. The control group was the autopolymerizing GC fuji Glass Ionomer cement(2.2:1 P/L ratio) and the experimental groups were made by following procedure. To induce the polymerization by visible light, the powder of GC Fuji II GI cement and the liquid of vitrabond for base & liner were mixed in an amalgam capsule with 2.5:1, 3.0:1, 3.5:1 P/L ratio(% wt/wt). After fabrication of specimens, compressive strenght, fracture toughness (K_IC), Scanning Electron Microscope and X-ray Diffraction, water-leachable content, marginal leakage and surface roughness were studied. The results were as follows : 1. Only experimental No. 1 group(visible Light curing) showed less compressive strength than control group I hour after curing. strength was increased with aging in all groups, so the compressive strength of light curing groups was no less than that of autopolymerizing group after 3 weeks. 2. Experimental No.3 group(visible Light curing) was inferior to No. 2 group(visible Light curing) in fracture resistance but light curing groups were more resistant to fracture than autopolymerizing group and showed ductile fracture pattern as compared with the brittle fracture pattern of autopolymerizing group. 3. From scanning electron microscopic image, various sized unreacted powder particles, surrounded by silica gel, were embedded in polysalt matrix. Light curing groups showed little crack and more dense unreacted particles than autopolymerizing group. 4. From X-ray diffraction analysis, GC Fuji II Glass Ionomer cement powder and all groups showed glassy appearance but light curing groups seemed to be more intensive in crystaline than autopolymerizing. 5. The most significant dissolution was shown in early setting period in all group. Light curing groups were dissolved less than autopolymerizing group. 6. Marginal leakage was not different significantly in case of cavity margin composed of same tooth structure(ex. only enamel margin, only dentin margin) but much more leakage was shown in dentin/cementum margin than enamel margin. In only case of only enamel margin, light curing groups were superior to autopolymerizing group. 7. All groups showed relatively smooth surface, which inegularity was less than l μm. Light curing groups were smoother than autopolymerizing group.

Iridoid 화합물이 치수절단 후 잔존치수 조직에 미치는 영향

권혁춘,박동성,손호현 大韓齒科保存學會 1997 Restorative Dentistry & Endodontics Vol.22 No.2

Aucubin, an iridoid glucoside, which is isolated form Aucuba japonica, has some biological effects. This study was to investigate the effect of aucubin on the remainig pulp tissues after pulpotomy. Mongrel dog's coronal pulps were mechanically exposed with a sterile round bur and excised with sterile sharp excarvator. After bleeding was controlled, in control group, Ca(OH)_2 powder was applied on the remaining pulps and the cavities were sealed with Z.O.E cement. In experimental group 1, mixed powder with Ca(OH)_2 and aucubin(1:1 by weight) was applied on the pulotomized pulp surfaces. After th cavities were covered with sterile aluminum foil, they were sealed with Z.O.E. cement. In experimental group 2, only aucubin powder was applied on the remaining pulps and then they were treated the same as experimental group 1. In the all groups, the pulps were histopathologically observed by light microscope at the time intervals of 1, 2 and 4 weeks after experiment. The results were as follows: 1. In control and experimental groups, mild vascular congestion and bleeding were found in most of the specimens. Less inflammatory infiltration was observed in experimental groups than in control group. 2. Dentin bridge formation was found after 1 week at both control and experimental group 1. Dentin birdge had discontinuous osteodentin like appearance of contained some dentin chips. In experimental group 2, dentin bridge was not seen. 3. The coagulation necrosis layer on the remaining pulp tissues was seen in all groups. In experimental group 2, the thickest layer was observed. And in control group, coagulation necrosis layer was similar as in experimental group 1.

편마비 환자의 비대칭적 체중지지가 기립균형 안정성 한계에 미치는 영향

권혁철,정동훈 한국전문물리치료학회 2000 한국전문물리치료학회지 Vol.7 No.2

창원지역 중고등학생들의 환경보전에 관한 의식분석

권혁범,이동근,김종오 경상대학교 환경보전연구소 1998 環境保全硏究所報 Vol.6 No.1

This study has been carried out to investigate the consciousness of the middle and high school students in Changwon city on environmental protection. A certain logical questionnaire containing various environmental items was answered by the 432 students, and the results could be summarized as follows : 1. The students were very interested in environmental problems, and they also worried about environmental problems more deeply than the other problems such as a threat of war, a population explosion and a exhaustion of resources. 2. Most of the students took the underground water as a drinking water and they didn't believe that the water supplied by the local government is safe enough for drinking. Therefore, the administration has to try to purify water further in order to recover the belief on environmental policies of the local government. 3. Most of the students said that the more academic subjects associated with environmental problems are needed to obtain detailed knowledges about environmental problems and protection. They generally meet the environmental problems through the mass communications such as TV and radio. When the academic subjects concerning about environmental problem are open in the curriculum, they wanted to attend the class readily. 4. The students recognized that environmental problems are serious. Although they think that they should do their best to solve the environmental problems, they actually were not active enough to put their thought in practice.

생물막 반응조에서 돈사폐수의 유기물 특성 및 동력학계수 산정

한동준,임재명,권재혁 江原大學校 産業技術硏究所 1996 産業技術硏究 Vol.16 No.-

This research was performed for the fundamental data using a advanced treatment process of piggery wastewater. Characteristics of influent wastewater was divided with various methods in fixed biofilm batch reasctor. Fractons of organic were divided into readily bioderadable soluble COD(Ss), slowly biodegradable COD(Xs), nonbiodegradable soluble COD(S?),and nonbiodegradable suspended COD(X?). Experimental results were summerized as following : i)biodegradable organics fraction in piggery wastewater was asbout 88.1 percent, and fraction of readily biodegrasdable soluble COD was about 66.1 percent. ii)Fractions of nonbiodegradable soluble COD was 11~12 percent, and soluble inert COD by metabolism was producted about 6~8 percent. iii) Active biomass fraction of attached biofilm was about 54.7percent, annd substrate utilization rate and maximum specific growth rate of heterotrophs were 8.315 d and 3.823 d? respectively.

증발기용 튜브의 내부 나선홈에 의한 열전달 특성과 압력손실에 관한 연구

조동현,권혁홍 대진대학교 1995 大眞論叢 Vol.3 No.-

Heat transfer performance improvement by fin and grooves is studied for evaporation of R-11 on integral-fin tubes. Eight tubes with trapezoidally shaped integral-fins having fin density from 748 to 1654fpm and 10, 30 grooves are tested. A plain tube having the same diameter as the finned tubes is also used for comparison. R-11 evaporate at saturation state of 23.6 C on the outside tube surface hotted by inside water flow. All of test data are taken at steady state. The heat transfer loop is used for testing single long tubes and hot water is pumped from a hot water boiler through filters and flowmeters to the horizontal test section where it is hotted by boiling on the outside of the tubes. The pressure drop across the test section is measured by means pressure gauge and manometer. The results obtained in this study is as follows : 1. Based on inside dimeter and nominal inside area, overall heat transfer coefficients of finned tube are enhansed up to 1.6-2.1 times that of a plain tube at a constant Reynolds number. 2. Friction factors are up to 1.6-2.1 times those of plain tubes. 3. The constant pumping power ratio for the low integral-fin tubes increase directly with the effective area to the nominal area ratio, and with the effective area diameter ratio. 4. A tube having a fin density of 1299fpm(fin per meter) and 30 grooves has the best heat transfer performance.

체위에 따른 균형 안정성 한계의 비교

정동훈,권혁철 한국전문물리치료학회 1999 한국전문물리치료학회지 Vol.6 No.1

Fabry-Perot 간섭형 광섬유 센서의 제조 및 온도특성

朴東洙,權大赫 慶一大學校 1993 論文集 Vol.9 No.1

A fiber optic Fabry-Perot interferometric sensor, compared with conventional sensor, has many advantages, such as high sensitivity in the wide range, rapid response, point measurement and multi-point detction. The Fabry-Perot interferomentric sensor was fabricated using TiO₂ thin film which has high refractive index and transparency in the visible and infrared and impervious of water vapor. The temperature dependent characteristics of the fiber optic sensor was investigated. As the result, it showed stable and linear response in the temperature range of 50~500℃.