• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.118-124
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• 2006

The characteristic of sheet metal process is the few loss of material during process, the short processing time and the excel lent price and strength. The sheet metal process with above characteristic is common used in industrial field, but in order to analysis irregular field problems the reliable and economical analysis method is demanded. Finite element method is very effective method to simulate the forming processes with good prediction of the deformation behavior. Among Finite element method, the static-implicit finite element method is applied effectively to analyze real-size auto-body panel stamping processes, which include the forming stage. In this paper, it was focused on the drawing ability factors on auto-body panel stamping by AUTOFORM with using tool planning alloy to reduce law price as well as high precision front Design Optimization of die. According to this study, the results of simulation will give engineers good information to access the Design Optimization of die.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.06a
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• pp.81-85
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• 2006

The characteristic of sheet metal process is the few loss of material during process, the short processing time and the excellent price and strength. The sheet metal process with above characteristic is common used in industrial field, but in order to analysis irregular field problems the reliable and economical analysis method is demanded. Finite element method is very effective method to simulate the forming processes with good prediction of the deformation behaviour. Among Finite element method, The static-implicit finite element method is applied effectively to analyze real-size auto-body panel stamping processes, which include the forming stage. In this paper, it was focussed on the drawability factors on auto-body panel stamping by AUTOFORM with using tool planing alloy to reduce law price as well as high precision from Design Optimization of die. According to this study, the results of simulation will give engineers good information to access the Design Optimization of die.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.84-91
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• 2010

The bonding process of LCD panel is attaching an inner lead to an outer lead in the production line of LCD panel module. It is composed of an OLB process and a PCB bonding process. Since bonding tool assembly is one of the core parts of the bonding equipment that determines the durability and performance of the final product, much design efforts to enhance uniformity and efficiency of the process have been made. In this paper, FE analyses have been employed to determine the bonding tool size. Bonding tool of long bar shape has been simplified as a piece with same heater pitch, and appropriate boundary conditions such as convection and radiation are considered. Thermal analysis results by the FEM have been validated by the experiments. With the use of FE analysis varies design parameters and the corresponding effects have been evaluated. It was observed that the approach presented in this paper could be employed for the design of LCD module bonding tool.

• Health Policy and Management
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• v.31 no.4
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• pp.531-543
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• 2021

Background: Population aging is a serious problem in Korea. And we have experienced a rapid increase in the health expenditures of the elderly. The purpose of this paper is to analyze the effect of having a usual source of care (USC) for the elderly. Methods: This study used the Korea Health Panel Survey data of 2012, 2013, 2016, 2017, and 2018. The sample was the person who answered the USC questions among the elderly. The panel logit model was used to analyze the determinants of having USC and the panel simultaneous equation model was used to analyze the effect of having USC among the elderly on the medical expenses, medical utilization, and subjective health status. Results: The estimation result shows that age, income, marriage, and so forth turn out to be the factors of having USC. Having the clinic level USC is estimated to reduce the health care utilization and the health expenditure and to improve the subjective health status. Conclusion: It is expected that the result of our analysis will provide evidence for encouraging having USC.

• Steel and Composite Structures
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• v.32 no.2
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• pp.265-279
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• 2019

The self-centering capacity and energy dissipation performance have been recognized critically for increasing the seismic performance of structures. This paper presents an innovative steel moment frame with self-centering steel reinforced concrete (SRC) wall panel incorporating replaceable energy dissipation devices (SF-SCWD). The self-centering mechanism and energy dissipation mechanism of the structure were validated by cyclic tests. The earthquake resilience of wall panel has the ability to limit structural damage and residual drift, while the energy dissipation devices located at wall toes are used to dissipate energy and reduce the seismic response. The oriented post-tensioned strands provide additional overturning force resistance and help to reduce residual drift. The main parameters were studied by numerical analysis to understand the complex structural behavior of this new system, such as initial stress of post-tensioning strands, yield strength of damper plates and height-width ratio of the wall panel. The static push-over analysis was conducted to investigate the failure process of the SF-SCWD. Moreover, nonlinear time history analysis of the 6-story frame was carried out, which confirmed the availability of the proposed structures in permanent drift mitigation.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.14 no.2
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• pp.67-78
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• 2010

An elastic field composed of symmetric cross-ply laminated material is analyzed in roller guided panel. The plane stress elasticity problem is formulated in terms of two displacement parameters with mixed boundary conditions. The numerical solution for two displacement parameters is obtained using a finite element method considering a panel of glass/epoxy laminated composite. Some components of stress and displacement at different sections of panel are displayed. The results makes sure that the formulation developed in this study can be applied to analyze the characteristics of elastic field made of laminated composite under any boundary conditions.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.8 s.101
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• pp.924-930
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• 2005

Sound absorptive materials have good performance in high frequency range, not at low frequencies. Therefore it has been great challenge to develop a sound absorbing structure that is good at low frequency. We propose to use a Helmholtz resonator array panel for this purpose. A Helmholtz resonator is one of noise control elements widely used in many practical applications. The resonator is a simple structure composed of a rigid-walled cavity with a neck, but it has very high performance at resonance frequency. This paper discusses the sound absorption of Helmholtz resonator array panels at normal and random incidence. First, various experimental results are introduced and studied. Secondly, we theoretically predict the absorptive characteristics of the resonator away panel. The theoretical approach is based on the Fourier analysis for a periodic absorber. We believe that this method can be used to design a panel for low frequency noise control.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.78-85
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• 2005

The static implicit finite element method is applied effectively to analyze total roof panel stamping processes, which include the forming stage. complicated and abnormal Large size roof panel was analyzed by using commercial program called AutoForm. Analysis results examining possibility and validity of the AutoForm software and the factor study are presented. Further, the simulated results for the total roof panel stamping processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

• Transactions of Materials Processing
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• v.24 no.4
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• pp.248-255
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• 2015

The warm drawing of magnesium alloy AZ31B sheet is affected by temperature because tensile elongation is changed due to the elevated temperature. In the current study, the effect of temperature was investigated for an automotive dash panel part by both experimental and FE analysis. Tensile tests were performed to obtain mechanical properties for various temperatures. AZ31B alloy sheet shows increased total elongation with increasing deformation temperature in the range of 200 to 300℃. The heating channel inserted into the die was used to regulate and to obtain an optimal temperature. A temperature controller was constructed to reduce temperature variation. Warm drawing of magnesium alloy AZ31B was performed to produce the desired shape of the lightweight automotive dash panel. The simulated results showed good agreement with the experimental results.

• Journal of the Korean Vacuum Society
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• v.1 no.3
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• pp.323-331
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• 1992

다층 panel형 cryoarray를 갖는 원통형 cryopump의 정적 pumping 특성을 view factor를 이용한 수치적 방법으로 해석하였다. 해석모델은 단순 원판을 기본으로 하고, 여기 에 상향 및 하향의 skirt를 부착한 실질적 array를 대상으로 하였으며, 형상, 크기 및 panel 개수를 변화시키면서 array 전체의 총 pumping 효율과 array 내의 pumping 속도 분포를 모두 구하였다. 다층 panel array에서도 single panel의 경우와 같이 type III 개스(He, H2) 에 있어서는 pumping 효율을 최대로 하는 최적의 크기가 있으며, panel 수효가 증가하면 pumping 속도는 약간만 증가하나 총 pumping 용량은 이에 비례하여 증가한다. Skirt의 각 도를 상향으로 변화시키면 type III 개스의 상대적 pumping 속도가 증가되며 type II 개스에 의한 cryosorbent의 오염도는 대략 10% 정도이다.