• 한국가시화정보학회지
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• 제4권2호
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• pp.59-68
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• 2006

We have evaluated the performances of the following six interpolation schemes used for win-dow deformation in particle image velocimetry (PIV): the linear, quadratic, B-spline, cubic, sinc, Lagrange interpolations. Artificially generated images comprised of particles of diameter in a range pixel were investigated. Three particle diameters were selected for detailed evaluation: pixel with a constant particle concentration $0.02particle/pixel^2$. Two flow patterns were considered: uniform and shear flows. The mean and random errors, and the computation times of the interpolation schemes were determined and compared.

• 대한기계학회논문집A
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• 제28권11호
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• pp.1646-1655
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• 2004

A description of the basic principles of moire interferometry leads to the design of a eight-mirror four-beam interferometer for obtaining fringe patterns representing contour-maps of in-Plane displacements. The technique is implemented by the optical system using an environmental chamber for submicro-displacement mesurement. In order to estimate the reliability and applicabili쇼 of the system developed, the measurement of coefficient of thermal expansion (CTE) for a aluminium block is performed. Consequently, the system is applied to the measurement of thermal deformation of a WB-PBGA package assembly. Temperature dependent analyses of global and local deformations are presented to study the effect of the mismatch of CTE between materials composed of the package assemblies. Bending displacements of the packages and average strains of solder balls are documented. Thermal induced displacements calculated by FEM agree quantitatively with experimental results.

• 한국의류산업학회지
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• 제21권4호
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• pp.468-479
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• 2019

This study used a three-dimensional-analysis method to quantitatively analyze the change of clothing appearance according to a gusset added to bodice and sleeve patterns for men in their twenties. Comparing six different patterns, the study found that patterns P1 and P2 with little gusset did not have a large difference in the strain map, and pattern P6 had no gusset in the motion of raising the arm $28^{\circ}$ to the side (M1). When the arm was raised $45^{\circ}$ to the side (M2), the P1 pattern had the smallest deformation, and only the P5 pattern had a large deformation from the neck to the armhole area. In contrast, except for in the P3 pattern, large wrinkles formed in the front and back when the arm was raised above $158^{\circ}$ (M3) from the side of the waist to the armpit. In addition, P3 had the smallest change in the hem of the bodice and sleeves. However, the appearance of P2, P3, and P5 was excellent when the arm was moved forward (M4), and the P2 and P5 patterns were the smallest at the bodice and sleeve hem. The P6 pattern showed the least fitness in terms of function. In the case of raising the arm, there was a strong correlation between gusset size and motion function, but when the motion of the arm changed, the motion function did not improved just by changing the ease size.

• 전자공학회논문지B
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• 제31B권10호
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• pp.140-148
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• 1994

본 논문에서는 입력영상에 존재하는 복수 패턴을 한번의 패스(pass)로 인식할 수 있는 변형된 네오코그니트론을 제안한다. 변형된 네오코그니트론은 특징을 추출하는 S세포층 및 V세포층과 패턴의 크기, 이동, 회전 등 변형에 덜 민감하게 하는 C세포층으로 구성된 계층적 신경망이다. S세포와 V세포들은 DCC(don't care condition)을 적용하여 영상에 존재하는 모든 패턴에 대한 특징을 추출하는 역할을 하며, S세포와 C세포는 추출된 패턴에 대한 위치정보도 함께 가진다. 위치정보는 추출된 특징들이 서로 간섭을 받지 않고 올바른 특징만이 추출되도록 하는 데 이용된다. 제안한 방법은 피드백이 존재하는 선택적 주의 방법과는 달리 단일패스로 인식이 가능하므로 인식시간이 짧으며, DCC와 위치정보를 이용하므로 서로 접촉되어 있는 복수 패턴의 인식도 가능하다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1127-1128
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.101-102
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• 2010

• Design & Manufacturing
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• 제7권1호
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• pp.11-18
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• 2013

This paper presents the plastic inhomogeneous deformation behavior of bimetal composite rods during the axisymmetric and steady-state extrusion process through a conical die. The rigid-plastic FE model considering frictional contact problem was used to analyze the co-extrusion process with material combinations of Cu/Al. Different cases of initial geometry shape for composite material were simulated under different conditions of co-extrusion process, which includes the interference and frictional conditions. The main design parameters influencing on deformation pattern are diameter ratio of the composite components and semi-die angle. Efforts are focused on the deformation patterns, velocity gradient, predicted forming load and the end distance through the various simulations. Simulation results indicate that there is an obvious difference of forming pattern with various diameter ratio and semi-die angle. The analysis in this paper is concentrated on the evaluation of the design parameters on the deformation pattern of composite rod.

• 대한기계학회논문집
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• 제16권9호
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• pp.1728-1735
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• 1992

본 연구에서는 실시간 홀로그래피 간섭계(real time holographic interfero- metry ststem)를 구성하고 위상변이법과 디지탈 영상처리를 이용하여 물체 변형을 실 시간으로 자동 측정이 가능하도록 하였다. 한편 광학계 구성과 대상물체의 상태에 따른 오차 요인을 해석하기 위해서 외팔보를 대상물체로 하여 측정된 변형값과 이론값 을 비교하였다. 응용예로써는 터빈 블레이드(turbine blade)에 굽힘력이 가해질때 나타나는 미소변형을 측정하였다.

• 건축역사연구
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• 제4권1호
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• pp.9-28
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• 1995

How have they preserved the regional historic buildings in Korea? Do they preserve the original value as a historic building. Are there any artificial deformations deteriorating the quality of the buildings? Is the regional system for preservation effective agalnst the artificial deformations of the buildings? These questions are involved in the purposes of this paper. I investigated the historic buildings designated by Kyong-Nam provincial government. As the resuit, variouse patterns of artificial deformation were found. I found that the deformations may deteriorate the original quality of historic building, and it is related somehow to the limitations of regional system for preservation. So I suggest some alternative ideas for preserving the quality of historic buildings against artificial deformation : a. Present system for preservation is not effective for preserving various architectural value such as urban context and landscape, site planning techniques, function of a space, etc. Regional system should be revised for preserving their architectural value or meaning. b. Historic buildings should be classified and should have proper protecting area according to each architectural values or meanings, respectibly: Historic buildings with Urban context and landscape Historic buildings as a part of a complex Historic buildings as a behavorial setting. c. Historic buildings should be graded based on their quality. And standard and criteria for acceptable deformations should be established. d. Periodical inspections by experts should be carried out to check out the deformation.

• Elastomers and Composites
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• 제55권2호
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• pp.88-94
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• 2020

Automobile industry, along with the automobile steering system, is rapidly changing and developing. The constant velocity joint transmits power to the wheels of vehicles without changing their angular velocity based on the movement of the steering wheel. Moreover, it controls their movement to act as a buffer. In order to prevent the excessive increase in temperature caused by the movement of vehicles, boots are attached to the constant velocity joint and lubricant is injected into the boots. The boots maintain the lubrication and protect the constant velocity joint from sand, water, and so on. As the wheels of the vehicle rotate, the boots are acted upon by forces such as bending, compression, and tension. Additionally, self-contact occurs to boots. Therefore, their durability deteriorates over time. To prevent this problem, polychloroprene rubber was initially used however, it was replaced by thermoplastic polyester elastomers due to their excellent fatigue durability. In this study, the structural analysis of boots was conducted. The results showed the deformation patterns of the boots based on the translation and rotation of the constant velocity joint. Moreover, it confirmed the location that was vulnerable to deformation. This study can be used to potentially design high-quality constant velocity joint boots.