• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.659-667
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• 2009

Recently Song and Cheon (2006) and Cheon and Lim (2009) developed the generalized maximum entropy(GME) estimator to solve ill-posed problems for the regression coefficients in the simple panel model. The models discussed consider the individual and a spatial autoregressive disturbance effects. However, in many application in economics the data may contain nested groupings. This paper considers a two-way error component model with nested groupings for the ill-posed data and proposes the GME estimator of the unknown parameters. The performance of this estimator is compared with the existing methods on the simulated dataset. The results indicate that the GME method performs the best in estimating the unknown parameters in terms of its quality when the data are ill-posed.

• Transactions of Materials Processing
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• v.18 no.5
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• pp.371-376
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• 2009

An equivalent drawbead model(EDM) for sheet metal forming analysis, which replaces complex drawbead geometries with drawbead forces in modeling the stamping dies with finite elements, is experimentally verified and applied to the numerical simulation of auto-panel stamping process. The drawbead restraining and opening forces of elliptical drawbead, circular drawbead, square drawbead, and step drawbead are obtained by performing the drawbead pulling test and compared with those of EDM and commercial code models(CCM). Better agreement with experimental measurements is found in EDM than CCM. Furthermore, the excellence of EDM is demonstrated in its application to the auto-body stamping analysis.

• Transactions of Materials Processing
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• v.18 no.5
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• pp.416-421
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• 2009

The applications of the aluminum alloy sheets to the auto-body panels are dramatically increasing for weight reduction of the automobiles. However, low formability of the aluminum alloy sheet compared to the steel sheet can be obstacles in tool manufacturing processes. Therefore, many of yield criteria for the anisotropic materials such as the aluminum alloy sheet have been observed. In this study, the biaxial tensile test and FLD test for the aluminum alloy sheet are performed. The results are compared with Hill's 1948 and Hill's 1990 models by means of theoretical predictions. Finite element analysis was also performed using the proposed method for the real panel.

• KDI Journal of Economic Policy
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• v.40 no.3
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• pp.91-115
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• 2018

This paper aims to identify the most effective mode of development finance flows for the economic growth of middle-income developing and least developed countries, separately. It also attempts to confirm whether governance has any significant role in the causal relationship between development finance flows and economic growth. Policymakers in each developing country should select the most effective modality of development finance inflows among the different modalities (such as Official Development Assistance (ODA) grants, Official Development Assistance (ODA) loans, FDI, and international personal remittances) and expand it for their economic growth. Dynamic panel regression models were used on 48 least developed countries and 89 middle-income developing countries, respectively, during the Millennium Development Era: 2000-2015. The empirical analysis results show that ODA grants and remittances were most effective in promoting economic growth for least developed countries, while FDI was most effective for middle-income developing countries. These findings were not affected by the status of governance of the individual country.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.389-392
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• 2009

The application of an equivalent drawbead model(EDM) for sheet metal forming analysis, which adopts the forces instead of complex geometries in modeling the drawbead, to the numerical simulation of auto-panel stamping process is introduced in this study. In terms of the thinning and draw-in, better agreement with experimental measurements was found in EDM than in commercial code models so that the excellence of EDM in the accuracy of drawbead forces for the simulation of auto-body stampings was revealed.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.213-223
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• 2016

The validity of landfill gas models is an important problem considering that they are frequently used for landfill-site-related policy making and energy recovery planning. In this study, the Monte Carlo method was applied to an landfill gas generation model in order to enhance conformity. Results show that the relative mean deviation between measured data and modeled results (MD) decreased from 19.8% to 11.7% after applying the uncertainty range of Intergovernmental Panel on Climate Change (IPCC) to the methane-generation potential and reaction constants. Additionally, when let reaction constant adjust derived errors from all other modeling components, such as model logic, gauging waste, and measured methane data, MD decreased to 6.6% and the disparity in total methane generation quantity to 2.1%.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.71-71
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• 2009

Recently several LCD TV makers including Samsung, LG and Sony actively have released LED LCD TV models on market. LED LCD TV is just which applied LED BLUs so that its color contrast ratio fairly enhance up to 1 million:1 and its thickness minimize to a few mm. Even this aspect seems somewhat to be each panel maker's strategies for prior market occupations on whole TV market. Without regard to the reasons, we do obviously meet a new era of technically advanced LCD TV. However we have still lots of problems or issues which we must overcome technically including LED chip/packaging process, secondary optics treatment, heat managements and cost reduction issues. Here I would like to forecast market volume and trend of LED LCD TV first and then discuss above almost of technical issues and suggest their possible solutions. Even these solutions looks better technologies and if they may increase production cost significantly, we will not prefer to choice that technology since lower cost policy can open the market. Finally I'm trying to suggest how well LED, as future light source, can apply to future LCD TV technologies.

• Korean Medical Education Review
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• v.20 no.1
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• pp.6-14
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• 2018

In recent years, Korean medical schools have shown a growing interest in the longitudinal integrated clerkship (LIC) as a means of improving clinical education. Some overseas medical schools have tried the LIC since the 1970s. In the 1990s, several universities in the United States, Canada, and Australia introduced LICs. A variety of studies have confirmed positive results of the LIC. Traditional block-rotation is a discipline-based, inpatient-centered practice. Instead, under the LIC system, a medical student responsible for a panel of longitudinal patients observes developments of their diseases, serving several departments simultaneously. Overseas medical schools have different LIC models depending on their affiliate hospitals' sizes and characteristics. The purpose of this study is to introduce LIC practices in Harvard Medical School and University of California San Francisco, which could be applied by Korean medical schools. This paper also aims to find out the strategies that have been able to help the two US medical schools implement the LIC successfully.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.537-542
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• 2000

When visual intrusion Is an Important factor, it is desirable to find alternative methods of Improving the insertion loss of a noise barrier without Increasing the height. Therefore, the primary object of the work attenuate the noise due to railway by small interference device installed at noise barrier edge. In this paper the performance of noise barriers with attached interference device, in terms of shape, absorptive material and split panel, we examined using the boundary element approach. Also, the scale models are mounted in an anechoic chamber and the frequency of the sound sources are appropriately scaled to simulate full scale site conditions. Lastly, experimental measurements of the designs are executed for a range of frequencies and receiver positions, and are compared with the results of numerical modeling.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.373-374
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• 2015

This paper proposes a dynamic thermo-electric model that links electrical parameters with thermal parameters. In this model, the irradiance and ambient temperature are used to calculate the cell temperature based on a four-layer model that includes the PV cell and surround materials. The calculated cell temperature is then used in the electrical model to accurately adjust the PV electrical characteristics. Dynamic PV characteristics, parallel capacitive and series inductive components, are added to the conventional single-diode model. The results show the effectiveness of this model rather than other conventional models of a PV panel.