• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.16-28
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• 2007

Objective: Evaluation of individual growth is important in orthodontics. The aim of this study was to develop a convenient software that can evaluate current growth status and predict further growth. Methods: Stature data of 2 to 20 year-old Koreans (4893 boys and 4987 girls) were extracted from a nationwide data. Age-sex-specific continuous functions describing percentile growth curves were constructed using natural cubic spline function (NCSF). Then, final stature prediction algorithm was developed and its validity was tested using longitudinal series of stature measurements on randomly selected 200 samples. Various accuracy measurements and analyses of errors between observed and predicted stature using NCSF growth curves were performed. Results: NCSF growth curves were shown to be excellent models in describing reference percentile stature growth curie over age. The prediction accuracy compared favorably with previous prediction models, even more accurate. The current prediction models gave more accurate results in girls than boys. Although the prediction accuracy was high, the error pattern of the validation data showed that in most cases, there were a lot of residuals with the same sign, suggestive of autocorrelation among them. Conclusion: More sophisticated growth prediction algorithm is warranted to enhance a more appropriate goodness of model fit for individual growth.

• Convergence Security Journal
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• v.12 no.3
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• pp.115-121
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• 2012

Software failure time presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing. For data analysis of software reliability model, data scale tools of trend analysis are developed. The methods of trend analysis are arithmetic mean test and Laplace trend test. Trend analysis only offers information of outline content. In this paper, we discuss forecasting failure time case of failure time censoring. In this study, we predict the future failure time by using the curve regression analysis where the s-curve, growth, and Logistic model is used. The proposed prediction method analysis used failure time for the prediction of this model. Model selection using the coefficient of determination and the mean square error were presented for effective comparison.

• Electronics and Telecommunications Trends
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• v.5 no.3
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• pp.43-51
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• 1990

주요 17개국의 전기통신 보급율과 이용량을 이용하여 각 발전단계별 특징을 도출하였다. 아울러 전기통신수요의 특성과 전기통신산업의 다양화에 대한 분석을 하였으며, 전기통신 네트워크 발전과정의 국제비교를 통하여 특징들을 추출하였다.

• Environmental and Resource Economics Review
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• v.15 no.3
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• pp.405-423
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• 2006

This paper develops theoretical model between economic growth and pollution as follows: First, emissions are generated from final good production process and technology accumulation. Second, pollution is directly connected with increase in final good production or in consumption, Third, no pollution abatement activity would be undertaken. Fourth, reproducible factors associated with labor and capital input are used in production function. We also test the existence of nonlinear Dynamics between economic growth and pollution using an exponential smooth transition autoregressive model(ESTAR). We find the presence of nonlinear dynamics between economic growth and pollution with a time series data for Seoul. This result shows indirectly that an inverted U relationship between air pollution and economic growth exists.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2016.10a
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• pp.77-90
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• 2016

• Journal of Environmental Policy
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• v.10 no.4
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• pp.3-37
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• 2011

This paper investigates the existence of the environmental Kuznets curve (EKC) for carbon dioxide $CO_2$ emissions and its causal relationships with economic growth and openness by using time series data (1971-2006) from China (an emerging market), Korea (a newly industrialized country), and Japan (a developed country). The sample countries span a whole range of development stages from industrialized to newly industrialized and emerging market economies. The environmental consequences according to openness and economic growth do not show uniform results across the countries. Depending on the national characteristics, the estimated EKC show different temporal patterns. China shows an N-shaped curve while Japan has a U-shaped curve. Such dissimilarities are also found in the relationship between $CO_2$ emissions and openness. In the case of Korea, and Japan it represents an inverted U-shaped curve while China shows a U-shaped curve. We also analyze the dynamic relationships between the variables by adopting a vector auto regression or vector error correction model. These models through the impulse response functions allow for analysis of the causal variable's influence on the dynamic response of emission variables, and it adopts a variance decomposition to explain the magnitude of the forecast error variance determined by the shocks to each of the causal variables over time. Results show evidence of large heterogeneity among the countries and variables impacts.

• Journal of Technology Innovation
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• v.28 no.1
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• pp.1-30
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• 2020

The government has implemented policies to increase university technology commercialization while supporting university research over time. This paper adopts the neo-institutional theory and examines the effect of change in the government research funds that universities have received overtime on the change in their technology commercialization performance. It also investigates a location (Seoul metro or others) effect on the relationships. Using latent growth curve modeling (LGM), which is widely used for time-varying analysis, this study longitudinally analyzes 138 universities in South Korea over the past nine years from 2009 to 2017. The results indicate that the growth in the annual government research funds that universities attain affects the growth in the economic value of technology transfers. In addition, the relationship is stronger for universities in Seoul metropolitan areas than those in other areas. The relationships are intact with one-year lagging effects. The findings help understand the effectiveness of government R&D policies for promoting technology commercialization.

• Environmental and Resource Economics Review
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• v.12 no.3
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• pp.515-529
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• 2003

This theoretical model makes three contributions to the study on economic growth and environment. First, emissions are generated during final goods production and technology accumulation. Second, this paper assumes that pollution is directly increasing with increase in final goods output or in consumption. Third, we use reproducible factors associated with labor and capital input in production function and assume constant return to scale in reproducible factors. From growth rate condition we derived, increases in reproducible factors, increases in productivity of either the abatment or technology sector, and decrease in social discount rate would increase the sustainable growth rate. In empirical test, the environmental degradation did not effect the economic growth rate though other factors satisfied the growth rate condition equation. However, through the reinterpretation of this result, we found indirectly the fact of that an inverted U relationship between air pollution and economic growth rate would exist in 20 OECD countries using a panel data for the period of 1986~1995.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.2025-2033
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• 1999

In this paper, we forecast launching time of the commercial IMT-2000 service as feb. 2001, according to expert’s opinion, and most of they forecast rapid evolution. And, we propose two different models according to two cases for competition power of price for IMT-2000 service subscriber demand forecasting. In this paper, we combine the expert’s opinion method with the growth curve model for demand forecasting for new products in order to reduce error of the demand forecasting that haven’t past references. The estimation of needed coefficients for each growth curve model is based on experts’ subjective opinions.

• Survey Research
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• v.6 no.2
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• pp.75-101
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• 2005

This study introduces and analyzes the data from Directory of Korean NGOs, which was published in 1997 and again in 200, to conduct a quantitative research on the growth of civic organization in South Korea. This paper focus on the information on membership size and founding year which are essential indicators for the growth of organizations. Missing rates on those two indicators are checked to evaluate the quality of data. We examine the changes in membership size between the two time periods, 1996 and 1999. It shows that there is a considerable decrease in the membership size for civic and advocary organizations that are oriented to national issues. It suggests the competition among the organizations over limited resources, which is consistent with an assumption of ecological theory of organization on non-linear growth pattern. Using founding year data from 1945 to 1996, we estimate pseudo growth curves of civic organizations based on logistic growth curve model to discuss different growth patterns of organizations across areas of activities.