• KDI Journal of Economic Policy
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• v.28 no.1
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• pp.117-144
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• 2006

This study is to analyze the existence of the real buffer effect that reflects the effect of beginning-of-period inventory stocks effect on the demand for fixed investment, and the financial buffer effect indicates the substitution effect between end-of-period inventory stock and the source of financing for fixed investment. I use panel data of 361 Korean listed non-financial firms during 1990-2003. After the crisis, it also observed whether the relationship between inventory stocks and fixed investment has altered or not. I review the theoretical connection between inventory stock and fixed investment through the paper by Bo(2004) and estimate the investment model by the method of GMM-SYS. The results show negative relation between end-of-period inventory stock and fixed investment in the whole period and each period classified, also it confirms that the relation between fixed investment and end-of-period investment is significantly negative. It can be interpreted through two aspects that firms not only use inventory stock as a buffer in response to unexpectedly high demand, but also utilize inventory stock as a source of financing for fixed investment. The results imply that firm's decision-making is much correlated with production-and-inventory stock adjustment, decision-making about fixed investment, and decision-making about financial affairs.

• Communications for Statistical Applications and Methods
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• v.21 no.2
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• pp.193-200
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• 2014

It was recognized by some researchers that the disturbance variance in a censored regression model is frequently underestimated by the maximum likelihood method. This underestimation has implications for the estimation of marginal effects and asymptotic standard errors. For instance, the actual coverage probability of the confidence interval based on a maximum likelihood estimate can be significantly smaller than the nominal confidence level; consequently, a Bayesian estimation is considered to overcome this difficulty. The behaviors of the maximum likelihood and Bayesian estimators of disturbance variance are examined in a fixed effects panel regression model with a limited dependent variable, which is known to have the incidental parameter problem. Behavior under random effect assumption is also investigated.

• The Journal of Fisheries Business Administration
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• v.44 no.2
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• pp.19-33
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• 2013

China is the world's largest producer of aquatic products and its fishery sector is comprised primarily of aquaculture facilities, both fresh and seawater, and a much smaller wild catch component. The expansion of the aquaculture sector continues to boost China's aquatic output. The increase is attributable to several factors. Among them rapidly growing domestic demand is no doubt one of the most important reasons. Rapid economic growth and rising disposable income are influencing domestic consumption and the economic recovery of major import markets is further stimulating consumption of China's aquatic products. This paper tries to examine the status, trend and reasons of consumption of aquatic products in China. Based on the analysis on the consumption of aquatic products and its change, this paper utilizes panel regression model to estimate the affecting factors of aquatic products consumption in China. By using panel data between 1997 and 2010, the results indicate that income, urbanization, aging and dummy variable have positive effects and fish price index has negative effect on China's aquatic products consumption as predicted. However, effects of meat consumption and education on fishery consumption are totally opposite with our predictions. In other words, it turns out that meat consumption has positive effect on fish consumption while education turns out to have negative effect. Finally the member of household does not show any significant effect on consumption of aquatic products in China.

• Safety and Health at Work
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• v.2 no.2
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• pp.148-157
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• 2011

Objectives: Although compensation for occupational injuries and diseases is guaranteed in almost all nations, countries vary greatly with respect to how they organize workers' compensation systems. In this paper, we focus on three aspects of workers' compensation insurance in Organization for Economic Cooperation and Development (OECD) countries - types of systems, employers' funding mechanisms, and coverage for injured workers - and their impacts on the actual frequencies of occupational injuries and diseases. Methods: We estimated a panel data fixed effect model with cross-country OECD and International Labor Organization data. We controlled for country fixed effects, relevant aggregate variables, and dummy variables representing the occupational accidents data source. Results: First, the use of a private insurance system is found to lower the occupational accidents. Second, the use of risk-based pricing for the payment of employer raises the occupational injuries and diseases. Finally, the wider the coverage of injured workers is, the less frequent the workplace accidents are. Conclusion: Private insurance system, fixed flat rate employers' funding mechanism, and higher coverage of compensation scheme are significantly and positively correlated with lower level of occupational accidents compared with the public insurance system, risk-based funding system, and lower coverage of compensation scheme.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.5
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• pp.67-73
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• 2013

The conversion of solar radiation into electrical energy by Photo-Voltaic (PV) effect is a very promising technology, being clean, silent and reliable, with very small maintenance costs and small ecological impact. The output power produced by the PV panels depends strongly on the incident light radiation. The continuous modification of the sun-earth relative position determines a continuously changing of incident radiation on a fixed PV panel. The point of maximum received energy is reached when the direction of solar radiation is perpendicular on the panel surface. Thus an increase of the output energy of a given PV panel can be obtained by mounting the panel on a solar tracking device that follows the sun trajectory. Tracking systems that have two axes and follow the sun closely at all times during the day are currently the most popular. This paper presents research conducted into the performance of Solar tracking system with photosensors. The results show that an optimized dual-axis tracking system with photosensor performance and analysis. From the obtained results, it is seen that the sun tracking system improves the energy and energy efficiency of the PV panel.ti-junction CPV module promises to accelerate growth in photovoltaic power generation.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.11a
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• pp.1213-1244
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• 2017

This study used a resource-based perspective to analyse the effects of organizational composition on the R&D performance of science and technology government-funded research institutes (GFRIs). We assumed that the composition of each GFRI would eventually be regarded as absorptive capacity and act as a moderating variable between R&D investment and performance. We used a panel generalized least squares (GLS) model with fixed effects to analyse panel data from 115 Korean GFRIs between 2011 and 2015. Our findings show that R&D investment of GFRIs has a direct and positive effect on performance. We also analysed how organizational composition can moderate the effect of R&D investment on performance. The findings provide evidence that organizational composition plays a moderating role between R&D investment and performance. Finally, this study discusses policy implications, its limitations, and also highlights future research directions.

• Journal of Ship and Ocean Technology
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• v.12 no.3
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• pp.14-25
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• 2008

Recently, there has been a serious effort to design a wing in ground effect (WIG) craft. Vehicles of this type might use low aspect ratio wings defined as those with smaller than 3. Design and prediction techniques for fixed wings of relatively large aspect ratio are reasonably well developed. However, Aerodynamic problems related to vortex lift on wings of low aspect ratio have made it difficult to use existing techniques. In this work, we firstly focus on understanding aerodynamic characteristics of low aspect ratio wings and comparing the results from experimental measurements and currently available numerical predictions for both inviscid and viscous flows. Second, we apply an improved numerical method, "B-spline based high panel method with wake roll-up modeling", to the same problem.

• Journal of Korean Society of Rural Planning
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• v.22 no.4
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• pp.103-114
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• 2016

The global trade partners have been diversified and mixed in agricultural market, which is expended the international agri-food market through the Regional Trade Agreement and World Trade Organization, etc. The aim of this study is to derive influential factors for exports increases of agricultural products targeting to Association of South-East Asian Nations (ASEAN). We set the equation for agricultural products exports referred to panel gravity model considering panel fixed effect for controlling endogeneity within variables. The results of this study are the follows; (1) Social economic distance considering international oil price negatively affects in the mushroom model; (2) Korean GDP affects (-) in a mushroom model and (+) in a vegetable model, however, ASEAN's per capita GDP indicates opposite influence in the same model; (3) Relative exchange rate shows negative impact in a vegetable model; (4) The entry status into WTO and the status in force of FTA have converse effects in mushroom and vegetable model, respectively.

• The Korean Journal of Applied Statistics
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• v.34 no.5
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• pp.697-710
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• 2021

Relative error prediction is preferred over ordinary prediction methods when relative/percentile errors are regarded as important, especially in econometrics, software engineering and government official statistics. The relative error prediction techniques have been developed in linear/nonlinear regression, nonparametric regression using kernel regression smoother, and stationary time series models. However, random effect models have not been used in relative error prediction. The purpose of this article is to extend relative error prediction to some of generalized linear mixed model (GLMM) with panel data, which is the random effect models based on gamma, lognormal, or inverse gaussian distribution. For better understanding, the real auto insurance data is used to predict the claim size, and the best predictor and the best relative error predictor are comparatively illustrated.

• Korea Trade Review
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• v.41 no.3
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• pp.177-198
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• 2016

China has retained economic growth rate of average 9% for more than ten years recently after China introduced capitalistic market economy system in 1979 by Deng Xiaoping. China has attracted foreign direct investment for a long time because it has retained very high economic growth rate, low labor cost, and various policies for foreign investors. This paper tries to analyse the determinants of foreign direct investment inflow after reform-opening of China with empirical analysis methods utilizing each province·city's specific characteristics by using the panel data from 1985 to 2013. For the empirical analysis we use random effect model, fixed effect model, pooled OLS, and random coefficient model. The results by pooled OLS and random coefficient model are presented for the comparison with the main results in the process of research. The research shows the results by fixed effect model are better than those by random effect model after doing Hausman's test. The results shows that GRDP, capital stock, and telecommunication exert a positive relationship with foreign direct investment, while express way variable exerts a negative one. China's education level surprisingly does not attract foreign direct investment even though it is not at a critical level. Therefore, the Chinese government should try to increase national income level as it symbolizes market size; encourage domestic investment; and construct high quality telecommunication infrastructure.