• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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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.

• Fashion & Textile Research Journal
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• v.21 no.4
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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.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.140-148
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• 1994

In this paepr, the modified neocognitron, which has capability of recognizing multi-patterns in input image in one pass, is proposed. It is the hierarchical neural network composed of S and V layer which are able to extract features and of C layer with little effect from deformation, changes in size, shifts in position. S and V cells extract the features of all patterns in input image by applying DCC(don't care condition) to those cells. S and C cells also have position informations of extracted patterns. Position information is used in extracting good features without extracted features beting interfered one another. The proposed method is shorter in recognition time than the selective attention method with backward connection, because of recognizing multi-patterns in one passe. The modified neocognitron can recognizze attached multi-patterns because of using DCC and position informations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1127-1128
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.101-102
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• 2010

• Design & Manufacturing
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• v.7 no.1
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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.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1728-1735
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• 1992

Holographic interferometry technique has been used for the measurement of whole-field deformation with high sensitivity. However there are some difficulties in quantitatively analyzing the holographic fringes. Recently, quantitative and automatic fringe analysis by using phase shifting method in interferometry has been studied in many fields. In this paper, a real time holographic interferometry system and a phase shifting method combined with digital image processing technique are employed to record and quantitatively analyze holographic fringe patterns. To evaluate our system and analyze errors, comparison of measured deformation with theoretical deformation of cantilever beam was carried out. The accuracy of 4.5% in our system was verified We have tried to apply this method to quantitatively measure the deformation of turbine blade under the bending force.

• Journal of architectural history
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• v.4 no.1
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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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• v.55 no.2
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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.

• Structural Engineering and Mechanics
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• v.40 no.2
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• pp.191-213
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• 2011

This paper presents an improved 8-node shell element for the analysis of plates and shells. The finite element, based on a refined first-order shear deformation theory, is further improved by the combined use of assumed natural strain method. We analyze the influence of the shell element with the different patterns of sampling points for interpolating different components of strains. Using the assumed natural strain method with proper interpolation functions, the present shell element generates neither membrane nor shear locking behavior even when full integration is used in the formulation. Further, a refined first-order shear deformation theory, which results in parabolic through-thickness distribution of the transverse shear strains from the formulation based on the third-order shear deformation theory, is proposed. This formulation eliminates the need for shear correction factors in the first-order theory. Numerical examples demonstrate that the present element perform better in comparison with other shell elements.