• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.391-394
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• 1998

The man-machine interface Is an important factor in the computer system, and it is thought that line-of-sight (LOS) detection technology will allow significant advances in this field. Techniques for detecting LOS for use in human interfaces have been studied［1]［2］. In earlier studies, however, LOS was detected with a head piece, goggles, or through fixing the position of the head. The limitations imposed by these fixed conditions render them unsuitable far use in interfaces, as they have adverse mental or physical effects on humans. Therefore. they have not been sufficiently developed for practical application. Research on non-contact LOS detection is expected to result in a usable LOS man-machine interface［3］［4］, and the current study is intended to be a step in that direction. The authors used color contact lenses for LOS detection, and applied this new method to a computer interface. The use of color contact lenses simplifies image processing. The algorithm used in this study is sufficiently accurate for practical applications. This technique can be used in input devices, in virtual reality applications, and in human engineering research.

• 폴리머
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• 제24권1호
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• pp.23-28
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• 2000

Solvent 용접에 따른 무정형 고분자 폴리스티렌/폴리스티렌 계면의 접착강도의 변화를 butt joint실험을 통하여 살펴보았다. 폴리스티렌과 용해도 상수가 유사한 용매를 계면에 코팅함으로써 계면 분자쇄의 유동성 증가와 계면의 거침정도의 변화에 따른 접촉표면의 증가로 인하여 접착 강도가 증가함을 확인하였다. 사용용매의 비등점이 접착온도보다 높은 경우, 접착강도의 증가는 용매에 의한 분자쇄의 유동성 증가에 기인되는 반면 용매의 비등점이 접착온도에 비해 낮을 경우 접착강도의 증가는 용매에 의한 접촉표면의 증가에 의존함을 알 수 있었다. 접착온도가 높을수록, 접착시간이 길어질수록 접착강도는 증가되며, 사용용매가 접착강도에 미치는 영향은 감소함을 알 수 있었다.

• 대한치과보철학회지
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• 제35권4호
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• pp.627-646
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• 1997

In order to find the degree of osseointegration at bone-implant interface of clinically successful implants, models including the 3.75mm wide, 10mm long screw type $Br{\aa}nemark$ implant as a standard and cylinder, 15mm long, 5.0mm wide, two splinted implants, and implants installed in various cancellous bone density were designed. Also, the amount of load and material of prostheses were changed. The stress and minimum contact fraction were analyzed on each model using three-dimensional finite element method(I-DEAS and ABAQUS version 5.5). The results of this study were as follows. 1. 10mm long, 3.75mm diameter-screw type implant had $36.5{\sim}43.7%$ of minimum contact fraction. 2. Cylinder type implant showed inferior stress distribution and higher minimum contact fraction than screw type. 3. As implant length was increased, minimum contact fraction was increased a little, however, maximum principal stress was decreased. 4. Implants with a large diameter had lower stress value with slightly higher minimum contact fraction than standard screw type. 5. Two splinted implants showed no change of minimum contact fraction. 6. The higher bone density, the lower stress value. 7. The material of occlusal surface had no effect on the stress of the bone-implant interface.

• 전자공학회논문지T
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• 제36T권1호
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• pp.51-57
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• 1999

본 논문은 온도센서 RSD. Pt 100Ω의 감지신호가 Temperature Controller의 릴레이 출력을 발생시키고 PLC 입력접점으로 입력시켜 1Scan Time으로 연산된 PLC 출력을 접점 P030에 Interface Unit를 연결시키므로 부하를 구동시키는 개발장비인 Wired Logic Type Unit에 대해서 기술하였다. 현재 PLC 교육장에서 프로그램 되어진 PLC가 부하를 구동시킬 수 있는 국내의 교육 PLC Test Kit로는 PLC와 부하 사이에 Interface 과정이 무시된 상태에서 PLC의 교육을 하도록 되어있다. 개발 키 트는 이 점을 보안하기 위해서 각종 센서 중 전자에서 언급한 온도 센서 Pt 100Ω을 이용한 온도 제어기의 릴레이 출력이 PLC 입력으로 피드백 되었을 때, 연산된 PLC 출력접점에 WLTU를 삽입시켜 PC, PLC와 부하 사이에 실시간 시스템으로 구동 시킬 수 있는 설비로, PLC 사용의 핵심원리를 쉽게 이해하고 알아 볼 수 있었다. 부하 Interface Unit인 WLTU의 구성은 구동 부분인 유 접점, 무접점, 센서, 지시 등, A접점, B접점 부하인 Motor로 나누었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제29회 춘계학술대회
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• pp.170-174
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• 1999

In order to analysis contact mechanism of head/ disk interface on hard disk drive, many techniques of analysis have been developed. Acoustic Emission sensor can be used for detect elastic energy of contact at head/disk interface. This work presents a good understanding of slider characteristics in frequency domain. The results show that torsional and bending mode of slider are dominant in head/disk contact.

• KSTLE International Journal
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• 제2권1호
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• pp.22-28
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• 2001

A resin bonded copper-graphite brush was investigated to evaluate the characteristics electrical signal transmission through a sliding contact as a function of the relative amount of graphite and copper in the brush. Particular attention was given to the correlation between electrical signal fluctuation and tribological properties in an electrical sliding contact system. A ring-on-block type tribotester was used for this experiment and the ring was made from pure copper. Results showed that a copper-graphite brush at a particular composition range exhibited the most stable frictional behavior with a minimum voltage drop. The amount of voltage drop at the friction interface was affected by the surface roughness, transfer film formation at the friction interface, and the real area of contact. Microscopic observations and the surface analysis showed a good agreement with the results from this experiment. The results also indicated that the electrical signal flunctuation was directly associated with the oscillation of the coefficient of friction during sliding by nanoscale variation of contacts at the friction interface.

• 한국재료학회지
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• 제26권10호
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• pp.556-560
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• 2016

Using current-voltage (I-V) and capacitance-voltage (C-V) measurements, the electrical properties of Au and Cu Schottky contacts to n-Ge were comparatively investigated. Lower values of barrier height, ideality factor and series resistance were obtained for the Au contact as compared to the Cu contact. The values of capacitance showed strong dependence on the bias voltage and the frequency. The presence of an inversion layer at the interface might reduce the intercept voltage at the voltage axis, lowering the barrier height for C-V measurements, especially at lower frequencies. In addition, a higher interface state density was observed for the Au contact. The generation of sputter deposition-induced defects might occur more severely for the Au contact; these defects affected both the I-V and C-V characteristics.

• Structural Engineering and Mechanics
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• 제15권6호
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• pp.609-628
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• 2003

Mechanical anchorage devices are generally tested in the laboratory and may be analyzed using the finite element method. These devices are composed of many components interacting through diverse contact interfaces. Generally, a Coulomb friction law is sufficient to take into account friction between smooth surfaces. However, in the case of mechanical anchorages, a gripping system, named herein the wedge-tendon system, is used to anchor the prestressing tendon. The wedge inner surface is made of a series of triangular notches designed to grip the tendon. In this particular case, the Coulomb law is not adapted to simulate the contact interface. The present paper deals with a new constitutive contact/gripping law to simulate the gripping effect. A parameter identification procedure, based on experimental results as well as on a finite element/neural network approach, is presented. It is demonstrated that all parameters have been selected in a satisfactory way and that the proposed constitutive law is well adapted to simulate the wedge gripping effect taking place in a mechanical anchorage device.

• 한국정밀공학회지
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• 제27권8호
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• pp.20-27
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• 2010

A precise evaluation of the contact position and the distribution of contact pressure in a wheel-rail interface analysis is one of the most important procedures to predict fatigue life and wear of wheel and rail. This paper presents the analysis result of finite element method(FEM) to investigate how the deformation of a wheelset, which is the assembly of wheel and axle of a railroad vehicle, affect the contact analysis of wheel and rail. 3D-FEM was used to analyze three contact models; a model with only wheel, a model with wheelset, and a model with simplified wheel and rail geometry. The analysis result of the contact position and the distribution of contact pressure are discussed. It is shown that the analysis results of a model with wheelset represent largest value with respect to contact pressure and contact stress. Furthermore, it is found that the distribution of contact pressure and the contact position is highly affected by the deformation of wheel and axle. It is concluded that the deformation of axle should be considered to evaluate the exact contact parameters in a wheel-rail contact analysis.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.251-254
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• 2003

In this study, main works are focused on investigating the stress distribution at the interface between a rotor core and Cu bar when a punch is applied into the body of Cu bar. A parametric study with dimensional changes of core slot was performed numerically to identify what factors are dominant in producing high contact forces in the interface. As analysis results, it was found that core slot length was a dominant factor in increasing contact force at the interface between a rotor core and Cu bar.