• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1265-1266
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• 2013

• Nuclear Engineering and Technology
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• 제43권5호
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• pp.447-458
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• 2011

This paper proposes an approximated contact force model to identify the nonlinear behavior of a fuel rod with gap supports; also, the numerical prediction of interfacial forces in the mechanical contact of fuel rods with gap supports is studied. The Newmark integration method requires the current status of the contact force, but the contact force is not given a priori. Taylor's expansion can be used to predict the unknown contact force; therefore, it should be guaranteed that the first derivative of the contact force is continuous. This work proposes a continuous and differentiable contact force model with the ability to estimate the current state of the contact force. An approximated convex and differentiable potential function for the contact force is described, and a variational formulation is also provided. A numerical example that considers the particularly stiff supports has been studied, and a fuel rod with hardening supports was also examined for a realistic simulation. An approximated proper solution can be obtained using the results, and abrupt changes from the contacting state to non-contacting state, or vice versa, can be relieved. It can also be seen that not only the external force but also the developed contact force affects the response.

• 한국안광학회지
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• 제10권4호
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• pp.411-417
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• 2005

본 연구의 목적은 Pure Vision 콘택트렌즈를 착용하여 착용자의 적응력을 조사하였다. 방법에서 피검자는 78명의 대학생들로 이들의 타각과 자각적 방법에 의해서 분석하였다. 매일 착용 또는 연속착용 동안 임상 적용에 대한 상대적인 결과들은 일주일 기간이 지난 후 분석을 하였다. 결과는 다름과 같다. 1. 시기능의 상태는 우수함 62.3%, 적당함 27.2%, 좋지 못함 10.6%이었다. 2. 부작용은 없음이 76.12%, 약간의 자극감이 18.21%, 그리고 심한 경험은 6.5%이었다. 3. 렌즈의 취급은 쉬움이 97.44%, 어려움이 2.56%이었다. 4. Pure Vision 렌즈의 특성에 대한 이해는 50.64%가 잘 이해를 잘하고 있었다. 결론적으로 대부분의 Pure Vision 콘택트렌즈 착용자들은 타각과 자각적으로 좋은 임상 반응을 가졌으나 약 절반정도는 렌즈의 특성을 충분히 이해하지는 못하였다.

• Physical Therapy Rehabilitation Science
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• 제12권2호
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• pp.167-176
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• 2023

Objective: The purpose of this study was to investigate the effects of anon-contact complex exercise program on muscle strength, fall efficacy, quality of life, and balance ability in older over 65 years of age. Design: A randomized controlled trial Methods: A total of 37 people in older over 65 years of age participated in the study. Random program was conducted and assigned to the experimental group (n=19) and the control group (n=18). Both groups performed the older people welfare center program. In addition, in the experimental group, a non-contact complex exercise program for muscle and balance exercise was performed. All interventions were performed 2 times a week, for a total of 6 weeks. chair stand test (CST), fall efficacy scale (FES), Euro quality of life 5 dimension (EQ-5D), Berg balance scale (BBS), timed up and go test (TUG), Fullerton advanced balance scale (FAB) were measured before and after the intervention to compare their effectiveness. Results: Both groups showed significant differences in CST, FES, EQ-5D, BBS, and TUG before and after intervention (p<0.05). FAB showed significant differences before and after intervention in all items except for FAB 8 and 9 items in the experimental group. In addition, the experimental group showed significant differences in CST, FES, BBS, TUG, FAB (except 1, 7, 8, 9) compared to the control group (p<0.05). Conclusions: The non-contact complex exercise program is an effective intervention method that has clinical significance in improving muscle strength, fall efficacy and static and dynamic balance abilities for the older over 65 years of age.

• JSTS:Journal of Semiconductor Technology and Science
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• 제1권1호
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• pp.20-30
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• 2001

A 1.8V $650{\;}\textrm{mm}^2$ 4Gb DRAM having $0.10{\;}\mu\textrm{m}^2$ cell size has been successfully developed using 0.11 $\mu\textrm{m}$DRAM technology. Considering manufactur-ability, we have focused on developing patterning technology using KrF lithography that makes $0.11{\;}\mu\textrm{m}$ DRAM technology possible. Furthermore, we developed novel DRAM technologies, which will have strong influence on the future DRAM integration. These are novel oxide gap-filling, W-bit line with stud contact for borderless metal contact, line-type storage node self-aligned contact (SAC), mechanically stable metal-insulator-silicon (MIS) capacitor and CVD Al process for metal inter-connections. In addition, 80 nm array transistor and sub-80 nm memory cell contact are also developed for high functional yield as well as chip performance. Many issues which large sized chip often faces are solved by novel design approaches such as skew minimizing technique, gain control pre-sensing scheme and bit line calibration scheme.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1065-1068
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• 2001

Effects of compacting pressure on the electrical and sintering characteristics of Cu25Cr contact material have been investigated. Cu25Cr contact materials were prepared by solid and liquid-phase sintering methods varying compacting pressure. Influence of compacting pressure on electrical characteristics were investigated in the cylindrical stainless-steel vessel using L-C resonant circuit. The physical and electrical properties of solid-phase sintered Cu25Cr material were found to be improved by increased compacting pressure. On the other hand, it was found that compacting pressure had little influence in case of liquid-phase sintered Cu25Cr material. After conditioning, contact resistance of Cu25Cr material was decreased regardless of compacting pressure. With increased compacting pressure, interrupting ability was shown to be increased.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.989-998
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• 2023

Under nuclear reactor severe accidents, the resuspension of radioactive aerosol may occur in the containment due to the disturbing airflow generated by hydrogen combustion, hydrogen explosion and containment depressurization resulting in the increase of radioactive source term in the containment. In this paper, for containment conditions, by considering the contact between particle and rough deposition surface, the distribution of the distance between two contact points of particle and deposition surface, rolling and lifting separation mechanism, resuspension model based on random contact with rough surface (RRCR) is established. Subsequently, the detailed torque and force analysis is carried out, which indicates that particles are more easily resuspended by rolling under low disturbing airflow velocity. The simulation result is compared with the experimental result and the prediction of different simulation methods, the RRCR model shows equivalent and better predictive ability, which can be applicable for simulation of aerosol resuspension in containment during severe accident.

• 센서학회지
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• 제31권3호
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• pp.139-144
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• 2022

Advanced tactile sensors are receiving significant attention in various industries such as extended reality, electronic skin, organic user interfaces, and robotics. The capabilities of advanced tactile sensors require a variety of functions, including position sensing, pressure sensing, and material recognition. Moreover, they should comsume less power and be bio-friendly with human contact. Recently, a tactile sensor based on the triboelectrification effect was developed. Triboelectric tactile sensors have the advantages of wide material availability, simple structure, and low manufacturing cost. Because they generate electricity by contact, they have low power consumption compared to conventional tactile sensors such as capacitive and piezoresistive. Furthermore, they have the ability to recognize the contact material as well as execute position and pressure sensing functions using the triboelectrification effect. The aim of this study is to introduce the progress of research on triboelectrification-based tactile sensors with various functions such as position sensing, pressure sensing and contact material recognition.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제1권1호
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• pp.1-8
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• 2020

Recent studies revealed that many animals identify individual humans. In this account, we review previous literatures on individual human recognition by wild or domestic animals and discuss the three hypotheses: "high cognitive abilities" hypothesis, "close human contact" and "pre-exposure to stimuli" hypothesis. The three hypotheses are not mutually exclusive. Close human contact hypothesis is an ultimate explanation for adaptive benefits whereas high cognitive abilities and pre-exposure to stimuli hypothesis are proximate explanations for mechanisms to perform such discriminatory behaviour. We report a case study of two bird species in a human-free habitat. Long-tailed skuas, which are known for having high cognitive abilities, exhibited the human discriminatory abilities whereas ruddy turnstones did not display such abilities toward approaching humans. This suggests that highly intelligent species may have this type of discriminatory ability so that they could learn to identify individual humans quickly by pre-exposure to stimuli, even in a human-free habitat. Here, we discuss that human recognition is more common in species with rapid learning ability and it could develop for a short period of time between an intelligent species and human.

• 아태비즈니스연구
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• 제12권4호
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• pp.271-288
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• 2021

Purpose - The purpose of this study is to identify the critical factors that restaurant management should consider strategically when making a decision after COVID-19 under the digital transformation and non-contact service expansions environment. Design/methodology/approach - The thirty six experts and managers who have 5 years or more experience in restaurant industry in Korea participate this study. The Analytic Hierarchy Process (AHP) and SER-M were used to analyze the experts' opinion Findings - As a result of the analysis, 'management environment' (0.313) showed the highest relative importance priority, followed by 'brand (0.263)', 'management characteristics (0.254)', and 'physical factors (0.17)'. And, as for the sub-factor value, 'lifestyle (0.087)', 'awareness (0.084)', 'consumer desire (0.075)', and 'loyalty (0.068)' were ranked highest among the 19 influencing critical factors. Research implications or Originality - In the case of large restaurant enterprises, it is judged that the subject(CEO, Management) is actively pursuing a strategy to acquire the necessary resources for the given environment of digital transformation and customer demand for non-contact services. On the other hand, in the case of middle and small restaurant enterprises, it seems that they are fully aware of the demand for expansion of non-contact services and the digital transformation required in the post COVID-19 era, but information technology utilization ability, usage experience, technology acceptance ability, and education and training support for this are only available to large enterprises.