• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.787-792
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• 1996

The method of manipulation by striking a part and letting it slide until it comes to rest, has been very little studied. However, the manipulation method is not uncommon in our daily lives. We analyze the dynamic behavior of a rigid polygonal part being striked and sliding on a horizontal surface under the action of fiction. There are two parts in this problem; one is the impact problem, and the other is the sliding problem. We characterize the impact and sliding dynamics with friction for polygonal parts, and present the possibility of reverse calculation for motion planning of striking operations. Using a high speed video camera, the computer simulation results are experimentally verified.

• 한국세라믹학회지
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• 제31권4호
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• pp.436-447
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• 1994

ZnO transparent conducting thin film, which is a strong candidate for a transparent electrical contact in optoelectronic devices, was prepared by the vapour spraying method on the slide glass in nitrogen ambient at the atmospheric pressure. The structural, optical and electrical properties of films show a strong dependence on substrate temperature, and the optimum range of deposition temperature existed to obtain TCO(Transparent Conducting Oxide) films. At the higher temperatures, milky films were obtained. In such optimum range, the bandgap in ZnO films was determined from the spectral dependence of absorption coefficient and electrical characteristics were characterized with by the Hall mobility and carrier concentration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.405-407
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• 2000

The most generally implemented method to detect the ground speed of the railway vehicles is to use the rotary type speed sensor attached to wheel axle. The Slip or sliding phenomenon on the railway vehicles occurs frequently caused by the weak viscosity of the wheel. Thus, precisely to control the car, the slip/sliding detection system is required. In this paper we proposed for the speed data management system, which uses rotary type speed sensor. Proposed speed management system can detect the slip/sliding with wheel axle as well as correct the generated speed error during in error time, to provide accurate speed and precise location data. The effectiveness for adapting to the railway system is clarified by the computer simulation.

• Steel and Composite Structures
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• 제51권5호
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• pp.575-586
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• 2024

Steel arch supports are used in mines and underground structures to provide stability. Most of the supports are made up of overlapping arches. They can behave either yieldingly or unyieldingly. If the normal force at any point of overlapping equals the slip resistance, the slide occurs. This paper presents a solution procedure for determining the load-carrying capacity of steel arch supports in the yielding implementation. This solution considers the effects of several significant elements, including differing materials and the number of clamps in yielding friction joints. The direct stiffness method is applied. The solution contains geometric, physical, and structural nonlinearity. The results obtained from numerical modeling using the provided procedure are compared to laboratory tests conducted at GIG Katowice in 2012. They show a good correlation with previously collected data from equivalent laboratory conditions.

• 한국결정성장학회지
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• 제4권2호
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• pp.199-209
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• 1994

Titanium tetra iso-propoxide와 Lead acetate trihydrate를 출발물질로 사용하여 제조한 졸을 현미경용 soda-lime-silica 슬라이드 유리, Si-Wafer 및 Sapphire 기판 위에 Dip-coating법으로 박막을 제조하였으며, 안정한 졸을 얻기 위하여 Acetylacetone을 첨가하였다. 졸의 점도, 조성등의 영향을 조사하였고, 조성변화, 막의 두께 변화, 열처리 온도에 따른 가시영역에서의 투과율과 굴절율 및 IR Spectra를 측정하였으며, $PbTiO_3$ 박막의 결정 생성 유무를 XPD로 검토하였다. 또하 EDX로 슬라이드 유리에서 박막으로의 확산 유무를 조사하였다. 제조된 졸은 20일동안 침전없는 안정한 상태를 유지하였다. 가시영역에서의 투과율은 열처리온도와 막의 두께가 증가함에 따라 감소하였고, flat한 투과특성을 나타내었다. 슬라이드 유리 위에 코팅한 $PbTiO_3$ 박막은 $600^{\circ}C$에서 열처리한 경우 Pyrochlore형이 나타났고, Si-Wafer와 Sapphire 기판 위에 코팅할 경우에는 $600^{\circ}C$에서 Pyrochlore형이 나타나기 시작하였으며, 열처리 온도가 높아짐에 따라 $800^{\circ}C$에서 $PbTi_3O_7$상이 나타났다.

• 한국산학기술학회논문지
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• 제16권10호
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• pp.6977-6984
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• 2015

품질 향상을 위해 연속적인 소성 변형을 이용한 롤 포밍 공정에 피어싱, 벤딩, 트리밍 등 별도의 가공공정을 통합한 볼 슬라이드 레일의 멀티 롤 포밍 공정의 필요성이 대두되고 있다. 하지만 프레스기의 진동 및 소음은 이 공정에서 생산되는 슬라이드 레일의 품질 저하를 유발한다. 본 연구에서는 롤 포밍 유한요소 프로그램으로 최적 변형률을 고려하여 롤을 설계하였다. 그리고 멀티 공정의 정적 안정성을 예측하기 위해 구조해석 프로그램으로 프레스기에 대한 응력 및 변형량을 계산하였다. 또한 공진영역에서의 장치들의 운전을 회피하기 위해 Modal 해석을 통해 1, 2차 모드에서의 고유진동수를 계산하였다. 그 결과 공정의 동적 안정성 개선을 확인하기 위해 마이크로폰과 가속도계를 이용하여 기존 및 연구 공정들의 소음, 진동의 크기를 비교하였다. 그리고 기존 및 연구 공정으로 생산되어진 레일의 폭 치수와 표면거칠기를 측정하였다. 따라서 해석 및 실험적 연구를 통해 멀티 롤 포밍 공정이 안정하다는 것을 알 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.662-669
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• 2006

PEM(Prestressed Earth Method) is a method to minimize lateral movements of the ground generated by progressive excavation and increases shear strength by applying prestresses to the end of earth bolt equipped with a P.C. panel after earth bolt is set up under the in-situ ground. In case of PEM, there are noticeable advantages. First of all, PEM maximizes the utility of the ground because PEM needs less volume of backfill and cutting than other general walls. Second, it's an environmental method possible to garden on the banquette. In this study, the behavioral characteristics of PEM are analyzed and compared with soil nailing system through the measured data of PEM and numerical method using SMAP-2D program and also an increased stability of PEM is evaluated by increasing prestress of earth bolts through the numerical analysis using Slide (ver. 4.0) program.

• 한국문헌정보학회지
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• 제17권
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• pp.85-103
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• 1989

The purpose of this second one of the two consecutive papers, which carried out for the research, is to evaluate their relative effectiveness regarding instruction with such three presentation methods as video/print+ lecture, print/video, print+lecture/video, with which the library of Duk Sung Women's University applied already for the orientation of the freshmen in 1988. In sum, the major research findings are as follows : First, as the more numerous media were applied for the orientation, the instruction were more effective. Second, it is very interesting to find out that there were wide differences in effectiveness among the three presentation methods applied for the student. Especially, the print+ lecture/video method was more effective in the instruction than the print/video method. Surprisingly, the video/print + lecture method was much more effective than the print+ lecture/video method. With the research findings of this two consecutive papers into consideration, it seems safe to say that the video-tape method was most effective among such three orienting methods as lecture, slide-tape, and video tape, and the video/print+lecture method was most effective among such three presentation methods as video/print+lecture, print/video, and print+lecture/video.

• 한국안광학회지
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• 제10권4호
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• pp.267-272
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• 2005

유기발광물질 $Alq_3$(alumina quinoline)의 단일박막을 열 증착(thermal evaporation)방법에 의하여 실리콘(c-Si)기판과 슬라이드유리(slide glass) 기판위에 제작하였다. 박막 제작 후 가변입사각운광타원계(VASE : Variable Angle Spectroscopic Ellipsometer)를 사용하여 1.50~5.0 eV 광 에너지 영역에서 타원 각(ellipsometry angle) ${\Delta}$, ${\Psi}$를 측정하였다. 이 측정결과들을 Jellison Modine 분산관계식을 사용하여 최적맞춤하고, 매개변수들을 구하여 박막의 광학상수인 굴절계수와 소광계수를 결정하였다. 결정한 광학상수의 정확성올 확인하기 위하여 투과율을 전산 시늉하고, 흡수계수(absorption coefficient)와 분광광도계로 측정한 흡광도(absorbance)의 스펙트럼 비교로 분석의 정확성을 확인하였다.

• 한국의류학회지
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• 제34권4호
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• pp.553-562
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• 2010

This survey investigates the conditions of summer working uniforms for contracted foodservice workers. The data were obtained from 67 workers through in-depth interviews (July 2005~October 2005). The results of study are as follows: The working environment changed to menu and cooking method (air temperature $28\sim37^{\circ}C$, humidity 72~86 %RH, radiant temperature $27\sim37^{\circ}C$, air velocity 0.14~0.37m/sec). They answered that the working environment has high temperatures, humidity, excessive noise, and liability to slide. The typical accidents were burns, cuts, slide, and ligament injuries in the workplace. Work duties consisted of cooking, serving food, washing, and cleaning up leftover food. All the employees carried out multi tasks. The primary working postures and motions were standing, crouching, and lifting. The female workers usually wore underwear (panty and brassiere), upper and lower work wear, aprons, waterproof-aprons, cotton-gloves, rubber-gloves, socks, and rubber-boots. The satisfaction of the uniform was relatively low for trousers and waterproof-aprons. The answer about the fit was generally "comfortable." They answered "back," "chest," and "head" were wet with perspiration during work. The uncomfortable parts were the crotch and neck. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly for ventilation and absorbency. In case of the colors of the working uniform, workers preferred white color for the upper part, and black color for the lower part.