• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.353-361
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• 1989

A parametric study of load distribution in bolt-nut joints is performed by the method of finite element contact analysis. The contacting surface is assumed unbonded and frictionless. Multi-body contact analysis is performed in elastic region under the assumption of axi-symmetric stress state. Load acting on the first thread from the fastened plate is much greater than that on the other threads in the standard setting. But the load distribution is shown to be improved by making the center of contact force acting on the nut surface move outwards. Such a modification is possible by enlarging the gap between bolt shank and fastened plate or by inserting suitable washers. Shape modification of the standard nut by the making a groove and a step on the nut surface is also suggested, which results in almost uniform load distribution and considerable decrease in the maximum stress of the joint.

• Science of Emotion and Sensibility
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• v.24 no.3
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• pp.41-60
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• 2021

The purpose of this research was to determine whether multimodal cues in an online shopping environment could enhance tactile consumer mental imagery, purchase intentions, and attitudes towards an apparel product. One limitation of online retail is that consumers are unable to physically touch the items. However, as tactile information plays an important role in consumer decisions especially for apparel products, this study investigated the effects of multimodal cues on overcoming the lack of tactile stimuli. In experiment 1, to explore the product, the participants were randomly assigned to four conditions; picture only, video without sound, video with corresponding sound, and video with discordant sound; after which tactile mental imagery vividness, ease of imagination, attitude, and purchase intentions were measured. It was found that the video with discordant sound had the lowest average scores of all dependent variables. A within-participants design was used in experiment 2, in which all participants explored the same product in the four conditions in a random order. They were told that they were visiting four different brands on a price comparison web site. After the same variables as in experiment 1, including the need for touch, were measured, the repeated measures ANCOVA results revealed that compared to the other conditions, the video with the corresponding sound significantly enhanced tactile mental imagery vividness, attitude, and purchase intentions. However, the discordant condition had significantly lower attitudes and purchase intentions. The dual mediation analysis also revealed that the multimodal cue conditions significantly predicted attitudes and purchase intentions by sequentially mediating the imagery vividness and ease of imagination. In sum, vivid tactile mental imagery triggered using audio-visual stimuli could have a positive effect on consumer decision making by making it easier to imagine a situation where consumers could touch and use the product.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.103-106
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• 2003

원형의 물체에 접해 있는 섬유 또는 실의 장력에 관하여 기존의 capstan equation의 잘못된 점을 보완하는 일반적인 capstan Equation을 유도하였다. 해석은 주로 섬유-물체의 접촉부위에 초점을 맞추었다. 그 결과 유도된 지배방정식은 2차 상미분 방정식의 형태를 갖는다. 지배방정식의 해를 구한 뒤, 접촉영역 전체에 작용하는 힘의 평형조건을 이용하여 입력 장력(incoming tension)과 출력 장력(outgoing tension)간의 관계식을 얻을 수 있었으며 우리는 이것을 True capstan equation이라 명하였다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.185-189
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• 1991

GaAs Schottky 접촉 전송선을 전극으로 하는 진행파형 광변조기의 특성이 분석되었다. 초고주파의 전파특성은 quasi-TEM 모델에 의해 분석되었으며, 고유치 방법과 유효 굴절율법을 결합하여 광파의 전파특성을 분석하였다. 또한 이를 통해 Schottky 접촉 전송선 및 광도파로의 기하학적 변수에 따라 진행파형 광변조기의 성능지수를 계산함으로써 최적 설계조건을 계산하였다.

• Journal of the KSME
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• v.26 no.1
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• pp.31-35
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• 1986

물질전달이 포함되는 교환기의 설계목표도 단순열교환기의 경우와 마찬가지로 여러 가지 주어진 제약조건(constraints; 예를들면 교환기의 제원이나 유체유동에 필요한 압력부하등)을 만족시키 면서 전달능력의 단위(number of transfer units, 이하 $N_{tu}$ 로 약함)를 최대로 해 주는데 있다. 그러나 교환장치들의 유형이나 형상에 따라 이같은 동일 목적을 위한 과정은 각양각색 이다. 본장에서는 직접 접촉식 교환기의 많은 종류중 물의 직접증발을 이용한 단열가습장치와 고체건조제 단열제습장치등 두가지의 해석과정을 예시하려고 한다.

• Tribology and Lubricants
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• v.31 no.5
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• pp.189-194
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• 2015

This paper focuses on the conformal contact problem. A typical example of conformal contact is the contact between a pin and hole. In particular, this paper focuses on the condition for assuming a contact stress field to be a Hertzian pressure profile by using well-known classical solutions associated with Hertzian contact. Persson first developed the conformal contact analysis method around half a century ago, but there have been no significant improvements since then. The present research also adopted this method, but developed new solutions from the viewpoint of application to structural design. The analysis began with a comparison between Persson°Øs conformal contact stress and the Hertzian stress fields. The next step was to check the differences in the normalized stress values of both. This study used the tolerance for the difference in the peak stresses of Persson°Øs solution and the Hertz solution to validate the Hertzian assumption. This gave the range for the difference in radii of the pin and hole when the contact force and mechanical properties of the material are specified. The results showed that, at a tolerance of 5%, the Hertzian assumption is valid if half of the contact angle is less than 35°ý. In addition, the Hertzian assumption holds even for a relatively long contact length, in contrast to the general incomplete contact problem. This paper discusses these results along with other aspects of the application to the design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.7
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• pp.117-125
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• 2004

Performing the sensitivity analysis of contact conduction on the basis of the thermal model already established, the study of thermal design is accomplished for the preparation of the future changes of mechanical interface design. A relatively simple thermal model is taken into consideration for the convenience of the analysis. A variety of the spacecraft bus voltages and the contact resistances are tried. As a consequence, when the mechanical interface condition is changed at the same module, the successful thermal design could be achieved if we design the heater to have sufficiently large power with reference to the heritage of contact resistance.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.358-363
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• 2008

Ultrasonic nonlinearity has been considered as a promising method to evaluate the micro damage of material; however, its magnitude is so small that its measurement is not easy. Thus, in this study, we investigate the effects of such experimental system dependent factors in the measurement of ultrasonic nonlinear parameter by using contact PZT transducer. Experimental results showed that the effect of system dependent nonlinearity is reduced when the contact pressure and transducer input voltage are sufficiently large. These results will be very useful to find out the proper experiment condition to measure rather accurate nonlinear parameter.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.96-96
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• 2013

그래핀과 금속 결합에서 발생하는 접촉 저항을 줄이기 위한 목적으로, 소자 제작에 사용되는 $SiO_2$ 기판의 표면을 플라즈마를 사용하여 에칭하는 최적의 조건에 대해 연구하였다. 기존에 발표된 연구 결과에 따라 $SF_6$와 $O_2$를 섞어 플라즈마 처리를 하였고, 플라즈마 방전에 사용 된 두 가스의 혼합 비율을 조절함으로써 소자 제작에 적합한 조건을 찾고자 하였다. 플라즈마 처리 전후의 $SiO_2$ 기판의 표면 측정은 AFM (Atomic Force Microscope)을 사용하였고, 단면은 SEM(Scanning Electron Microscope)을 통해 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.403-406
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• 2006

본 연구에서는 양극의 two-phase simulation 모델을 확립하고 GDL 물성과 작동조건이 전지성능에 미치는 영향에 대해 시행하였다. 모델로는 Multi-phase $mixture(M^2)$ 모델을 사용하였는데 이 모델은 각 상의 balance식을 하나의 mixture-phase식으로 통합하여 수학적 계산이 용이할 뿐만 아니라 실제 전지 성능에 매우 근사하여 신뢰성성도 확보할 수 있었다. 최적의 GDL 구조와 작동조건을 규명하기 위해 기체투과도, 접촉각, 기공도, 기체 공급가스 차이에 따른 전지 성능 분석을 시행하였는데 그 결과 모든 파라미터들이 증가할수록 비례적으로 전지 성능이 증가하였다. 기체 공급가스>기공도>>접촉각>기체투과도 순으로 전지에 미치는 영향이 큰 것으로 나타났다.