• 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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.429-436
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• 1998

In this paper, we derive the algorithm for calculating contact point between wheel and rail and develop the method for track modeling. The proposed methods use travelling distance to represent track center line poistion vector and track orientation with respect to Newtonian reference frame. The proposed methods can be easily used in multibody dynamic analysis. Two numerical examples are given to verify the validity of the proposed methods.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1115-1116
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.761-762
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• 2010

• 한국식생활문화학회지
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• 제25권3호
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• pp.312-323
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• 2010

The objective of this study was to examine the effects of relationships between food service companies and their client companies by surveying employees working at cafeterias among a food service companies' client companies. For this purpose, previous research was reviewed, and confirmatory research was conducted using a questionnaire. In the questionnaire survey, the subjects were sampled through convenience sampling from the client companies of A Food Service Company, and 182 valid questionnaires were used in the analysis. The results of this study are summarized as follows. First, the characteristics of the relationship between the food service company and its client companies, which were reputation, communication, operation skill, and contact-point employees' service quality, had a significant effect on trust, and the effect was high in the order of contact-point employees' service quality, communication, operation skill, and reputation. Satisfaction was significantly affected by reputation, operation skill, and contact-point employee' service quality, but not by communication. The effect was high in the order of contact-point employees' service quality, reputation, and operation skill. In addition, reputation, communication, operation skill, and contact-point employees' service quality had a significant effect on long-term orientation, and the effects were high in the order of reputation, contact-point employees' service quality, communication, and operation skill. Second, with regard to the quality of relationships between a food service company and its client companies, trust had a significant effect on satisfaction. Third, among the factors related to the quality of relationships between the food service company and its client companies, trust and satisfaction had a significant effect on long-term orientation, and the effect of satisfaction was higher than that of trust. This study has scientific significance as one of only a few studies on factors affecting the long-term relationship between food service companies and their client companies, along with managerial implications that contact-point employees' capabilities are most important in service businesses, and thus efforts should be made at employing and educating them properly.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.609-612
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• 2007

The HDD (hard disk drive) using Load/Unload (L/UL) technology includes the benefits which are increased areal density, reduced power consumption and improved shock resistance than those of contact-start-stop (CSS). Dynamic L/UL has been widely used in portable hard disk drive and will become the key technology for developing the small form factor hard disk drive. The main design objectives of the L/UL mechanisms are no slider-disk contact or no media damage even with contact during L/UL, and a smooth and short unloading process. In this paper, we focus on lift-off force, pitch static attitude (PSA), roll static attitude (RSA) and dimple point. The "lift-off" force, defined as the minimum air bearing force, is another very important indicator of unloading performance. A large amplitude of lift-off force increases the ramp force, the unloading time, the slider oscillation and contact-possibility. PSA and RSA are also very important parameters in L/UL system and stability of slider is mainly determined by PSA and RSA. Dimple point by PSA and RSA is also important indicator. Therefore we find the optimal dimple point of SFF HDD suspension for improving the unloading performance.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 추계학술대회
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• pp.26-27
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• 2019

선박 경계영역 이론에 의한 선박 사이의 실시간 범퍼면적을 갖는 타원형 범퍼가 서로 접하는 순간을 계산하기 위한 연구이다. 실시간 타원형 범퍼가 겹치는 순간을 인지하여 관제사들이 선박의 충돌위기를 느끼는 인지 위험 평가에 중요한 도구로 사용할 수 있다. 본 연구에서는 선박 사이의 충돌위기를 사전에 느끼는 선박 범퍼의 접촉을 컴퓨터 프로그램을 이용하여 다양한 각도에서 충돌위기를 미리 인지하여 선박 관제에 도움을 주기 위한 연구이다.

• 전기학회논문지
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• 제57권12호
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• pp.2291-2299
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• 2008

Hall effect force sensors have been used to measure clamping force in conventional Electric Parking Brake(EPB) systems. Estimation of clamping force without the sensors has drawn attentions due to mounting space limitations and cost issues. Removing the sensor requires the estimation of the initial contact point where the clamping force is effectively applied to the brake pads. In this paper, we propose how to estimate the initial contact point finding the relation between the angular velocity of an actuator and the initial contact point. For force estimation a look-up table is used as a function of the displacement of parking cable from the initial contact point. The proposed method is validated by experiments. From the experimental results we observe that the proposed method satisfies the specifications. The designed method is also able to estimate clamping force although parking cables are loosened and brake pads are worn out. Applying the proposed method enables manufacturing of low cost EPB systems.

• 한국철도학회논문집
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• 제15권1호
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• pp.1-8
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• 2012

윤축 동역학 해석은 철도차량 동역학 해석의 정밀도를 결정하는 핵심 요소이다. 본 연구에서는 정밀한 3차원 차륜-레일 접촉 해석을 윤축의 강체 운동 방정식에 적용하는 방법으로 3차원 윤축 동역학 해석을 수행하였다. 곡선 주행시 플랜지 접촉에 의해 차륜-레일 2점 접촉이 발생할 때 윤축의 동역학 해석이 가능한 수치해석 절차를 개발하였다. 윤축의 구속조건식과 강체 동역학 방정식을 Runge-Kutta 방법을 이용하여 수치적분을 수행하였다. 제안된 윤축 동역학 해석 결과는 VI-RAIL을 이용한 해석결과와 비교 분석하여 타당성을 검증하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.406-406
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• 2011

최근 결정질 실리콘 태양전지 분야에서는 태양전지의 Voc와 Isc의 증가를 통한 효율 향상을 목적으로 후면 passivation 박막에 대한 연구가 활발하게 진행되고 있다. Local-Back Contact Cell은 최적화된 후면 passivation 박막을 이용한 태양전지 제조방법이다. 본 연구에서는 고효율의 LBC 태양전지 개발을 위해 Rapid Thermal Oxide(RTO)를 이용한 후면 passivation 박막에 screen printing을 이용한 point contact 구조의 LBC 태양전지를 제작하고 그 특성을 분석하였다. 본 연구에 사용된 RTO 박막은 O2와 N2, 2L/min의 조건에서 $850^{\circ}C$에서 3분 동안 열처리하여 성장시켰다. 이렇게 성장된 박막은 3nm의 두께로 형성되어 passivation 효과를 나타내었으며, carrier lifetime 측정 결과 37.8us의 값을 나타냈다. 전면 ARC형성을 위해 RTO 박막 위에 PECVD를 이용하여 SiNx passivation 처리를 하였고, 그 결과 carrier lifetime은 49.1us까지 향상하였다. 후면의 전극 형성을 위해 screen printing 방법으로 Al point contact을 형성하여 local 한 BSF를 형성 시켰으며, 이후 후면 전극 연결을 위한 방법으로 300nm의 두께로 full Al evaporation 공정을 진행 하였다. 결과적으로 RTO 후면 passivation 박막에 Al point contact 형성을 통해 제작된 태양전지는, Suns-Voc 579mV, FF 82.3%, 16.7%의 효율을 달성하였다.