• PNF and Movement
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• 제19권2호
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• pp.233-242
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• 2021

Purpose: The purpose of this study was to determine the changes in foot contact area and pressure when walking with a functional insole that emphasizes the Hallux point as compared to a general insole. Methods: In this study, an experiment was conducted to investigate changes in plantar pressure and contact area for a functional insole that emphasized the Hallux point as compared to a general insole. A lower extremity robot was used for walking reproduction. First, the gait sequence according to the two insoles was determined through a randomized controlled trial comparison. According to the sequence procedure, the insole was attached to the shoe and then worn on the right side of the lower extremity robot for gait reproduction at a normal gait speed of 20 steps per minute. After programming the robot to walk, the experiment was carried out. The result value was determined by averaging the pressure and area data of the fore and rear foot measures after walking at 20 steps per minute. Results: The functional insole that emphasized the hallux point significantly increased the forefoot and rearfoot contact area (p < 0.05) and significantly decreased the forefoot and rearfoot contact pressure (p < 0.05) compared to the general insole. Conclusion: A functional insole that emphasizes the hallux point does not collapse the medial longitudinal arch during gait, increasing foot stability and reducing fatigue. Thus, this functional insole needs to be widely used clinically.

• Tribology and Lubricants
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• 제39권1호
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• pp.8-12
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• 2023

This study presents a molecular simulation of adhesion control between carbon nanotube (CNT) and Ag thin film deposited on silicon substrate. Rough and flat Ag thin film models were prepared to investigate the effect of surface roughness on adhesion force. Heat treatment was applied to the models to modify the adhesion characteristics of the Ag/CNT interface based on thermal wetting. Simulation results showed that the heat treatment altered the Ag thin film morphology by thermal wetting, causing an increase in contact area of Ag/CNT interface and the adhesion force for both the flat and rough models changed. Despite the increase in contact area, the adhesion force of flat Ag/CNT interface decreased after the heat treatment because of plastic deformation of the Ag thin film. The result suggests that internal stress of the CNT induced by the substrate deformation contributes in reduction of adhesion. Contrarily, heat treatment to the rough model increases adhesion force because of the expanded contact area. The contact area is speculated to be more influential to the adhesion force rather than the internal stress of the CNT on the rough Ag thin film, because the CNT on the rough model contains internal stress regardless of the heat treatment. Therefore, as demonstrated by simulation results, the heat treatment can prevent delamination or wear of CNT coating on a rough metallic substrate by thermal wetting phenomena.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.82-84
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• 2003

In case contact between point of contacts is not achieved well, contact resistance is grown, and by current concentration at current conducting contacts can weld. In order to decrease contact resistance between contacts in case of busbar, installing spring between fixed contact and moving contact. and then force on faying surface of contacts increase and contact resistance decrease. But, in case increase force of spring to widen contact area, operating force moving contact can grow, on the contrary force of spring is small, contact resistance becomes low. Therefore, need to optimize force and number of spring. position, and also need to examine force change on contact surface at point of contact moving. In this paper, dynamic kinetics analysis for force on faying surface of contacts is performed at unsteady state. It is showed to not uniform force on surface between contacts, and we can got more uniform force by means of change spring position.

• 대한물리치료과학회지
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• 제18권2호
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• pp.29-40
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• 2011

Purpose: The purpose of this study was to analyze the changes of parameters of foot contact by various carrying a pack methods during walking. Method: The subjects were consisted of normal forty four persons (males 30, females 14, mean age 23). The carrying a pack methods were classified into five conditions: carrying no bag(Con 1), carrying a backpack(Con 2), carrying a shoulder bag(Con 3), carrying a cross bag(Con 4), carrying a one-hand bag(Con 5). All subjects were participated in these five condition and measured foot pressure by F-scan system during walking. Then foot contact time, foot contact area, foot contact length and width were measured and analyzed. The repeated one-way analysis of variance (ANOVA) was used to get difference between conditions and independent t-test was used to get difference between left and right foot within condition. Result: In the comparison of parameters of foot, contact time, contact area and mid foot width were significantly different between conditions(p<.05), and in both foot contact time at condition 5 showed the most significant reduction(p<.05). In the comparison of parameters of foot between left and right foot within condition, every conditions were not significantly different(p>.05). Conclusion: In this study various carrying methods changed the parameters of foot contact and showed significant difference in some articles between carrying methods. However, asymmetric load of pack by carrying methods didn't affected symmetry of parameters of foot contact between left and right foot.

• 한국안광학회지
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• 제21권3호
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• pp.215-225
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• 2016

목적: 본 연구에서는 소프트콘택트렌즈의 재질 특성과 착색 여부가 눈물 성분이 침착된 소프트콘택트렌즈에 칸디다균 흡착에 미치는 영향을 알아보았다. 방법: Etafilcon A, hilafilcon B, nelfilcon A 재질의 투명 소프트콘택트렌즈와 써클 소프트콘택트렌즈를 대상으로 하여 인공눈물에 침착시키기 전과 후의 흡착 균 수를 측정하였다. 또한, 주사전자현미경을 통해 렌즈에 흡착된 균을 관찰하였다. 결과: 칸디다균의 흡착은 콘택트렌즈 재질에 따라 통계적으로 유의하게 차이가 있었다. Etafilcon A 재질에서는 투명 소프트콘택트렌즈와 써클 콘택트렌즈간 균 흡착양 차이가 없었으며, hilafilcon B 및 nelfilcon A 재질에서는 써클 소프트콘택트렌즈에 흡착된 균 수가 다소 많았다. 투명 중심부와 착색부를 비교하였을 때 투명 중심부에 칸디다균 흡착이 더 많았으며, 투명 중심부와 투명 주변부를 비교하였을 때 투명 주변부에서의 균 흡착양이 더 많았다. 눈물 단백질이 침착되었을 경우 흡착된 칸디다균의 수가 감소하였으며 눈물 단백질의 칸디다균에 대한 항균력 유지는 재질에 따라 차이가 있어 etafilcon A 재질 렌즈에서 유지 기간이 가장 길었다. 결론: 본 연구에서는 소프트콘택트렌즈의 재질 특성, 착색여부 및 부위에 따라 흡착되는 칸디다균수가 달라진다는 것을 밝혔으며, 칸디다균의 흡착 특성에 따라 관리 방법을 달리해야 할 것을 제안한다.

• 한국초전도ㆍ저온공학회논문지
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• 제17권4호
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• pp.1-7
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• 2015

This paper addresses technical problems of thermal contact conductance or resistance which inevitably occurs in most cryogenic engineering systems. The main focus of this paper is to examine what kind of physical factors primarily influences the thermal contact resistance and to suggest how it can be minimized. It is a good practical rule that the contact surface must have sub-micron roughness level with no oxide layer and be thinly covered by indium, gold, or Apiezon-N grease for securing sufficient direct contact area. The higher contact pressure, the lower the thermal contact resistance. The general description of this technique has been widely perceived and reasonable engineering results have been achieved in most applications. However, the detailed view of employing these techniques and their relative efficacies to reduce thermal contact resistances need to be thoroughly reviewed. We should consider specific thermal contact conditions, examine the engineering requirements, and execute each method with precautions to fulfil their maximum potentials.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.134-137
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• 2005

In this paper, a continuous contact treatment has been considered during FE-analysis of the sheet metal forming processes. Because the simulation is usually performed stepwise, the status of contact can change suddenly. In case of implicit scheme, the increment of punch stroke can be chosen as large value. For exact assessment of contact force and friction force between die and sheet, the continuous contact treatment is proposed. The virtual surface of sheet metal is modeled by NURBS curves or surfaces in order to calculate exact contact area and penetration depth. From the geometrical evaluation of contact behavior, additional contact pressure is imposed to the element. The deformation of bending process and hydroforming process are analyzed based on this scheme.

• 대한치과보철학회지
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• 제8권1호
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• pp.37-41
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• 1968

The purpose of this paper is to evaluate the number of occlusal contacts in centric occlusion. The 50 strictly selected subjects, who have good natural dentition and occlusion, were impressioned with Alginate Impression material, and dental stone models were madel. After transfering the models from mouth to Hanau Articulator Model H2 by means of SM type Face-Bow, condylar guidances were registered, red articulating papers($13{\mu}$ in thickness) were inserted between upper and lower posterior teeth, and the red marked points and lines were counted as occlusal contact points. 1. The number of occlusal contact points in centric occlusion were 1st Molars 2nd Molars, 2nd Premolars and 1st Premolars in order. 2. The number of occlusal contact points of right side showed comparatively much more than those of left side. 3. The number of occlusal contact points of upper in Premolar area were much more than those of lower, and in Molar area were the reverse. 4. The total number of occlusal contact points in centric occlusion were approximately 105 points.

• 대한물리의학회지
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• 제5권3호
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• pp.445-453
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• 2010

Purpose : The purpose of this study was to investigate the effect of pelvic tilt exercise with changing the body position on foot contact pattern in the hemiplegic patients. Methods : Thirty seven hemiplegic patients were randomly divided 3 groups; control group (CG), sitting exercise group (SIEG) and standing exercise group (STEG). F-mat system and F-scan system were used for the measurement of foot contact pattern of hemiplegic side in walking. Data were analyzed statistically using paired t-test and one-way ANOVA. Results : The results were as follows : 1) Contact area of CG and SIEG were not significant difference in walking. Contact area of STEG was significant increased in walking. 2) Anteroposterior distance of COP of SIEG and STEG were significant increased in walking. Conclusion : These results suggest that pelvic tilt exercise in sitting and standing position are effective in the improvement of Anteroposterior distance of COP and gait stability are increased in only standing position.

• 자원환경지질
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• 제25권4호
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• pp.463-477
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• 1992

The study area consists of sedimentary and volcanic rocks of Gyeongsang Supergroup, granitoid intrusives, and hornfelses around the granitoids. Granitoid intrusives occur in small stocks in Nijeon-ri, Uggogri, and Yul-ri area. The masses in Nijeon-ri and Uggog-ri are hornblende-biotite granodiorite, biotite granodiorite respectively, and Yul-ri mass is biotite granite. Surrounding sediments of these masses were thermally metamorphosed and contact aureoles were formed. The studied granitoids are considered to be formed by sequential crystallization-differentiation from calc-alkalic granitoid magma. Metamorphic minerals occurring in contact aureole are chlorite, actinolite, epidote, and biotite. Diopside and hornblende are observed in small amount in some lithology around contact aureole. The lithology of contact aureole is predominantly silty and sandy, and characteristic metamorphic minerals were poorly developed because of low temperature metamorphism. Low temperature in contact aureole could be deduced from the facts that the intrusions were small size, shallow depth, low temperature, and rare movement of volatiles from magma.