• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.4
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• pp.77-88
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• 2023

The purpose of this study is to confirm whether the current technology appraisal model for investment, which is designed to identify high-growth SMEs in sales, which is one of the characteristics of gazelle companies, has the possibility of expanding employment effects. For SMEs classified as technology investment adequate firms(TI1-TI6) through technology appraisal for investment between 2016 and 2018 were targeted. At this time, the employment effect was analyzed by dividing the absolute employment effect and the relative employment effect. As a result of the analysis, it was confirmed that the technology appraisal items for investment defined as innovation characteristics did not have significant explanatory power for the absolute employment effect. However, for the relative employment effect, among innovation characteristics, technicality(TC) was found to have significant explanatory power, and this is because the item appraised based on future growth potential. In particular, the relative employment effect is meaningful in terms of the actual employment effect, and the conclusion is drawn that the current technology appraisal model for investment is an appraisal model with the possibility of expansion in terms of employment effect.

• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.627-681
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• 2012

This paper starts with a model of monopolistic competition and endogenous growth, and it adds pollution as an input to production. Then I adopt environmental quality as a renewable resource used in production. I show that increasing returns due to specialization of clean activities as inputs can help lead to sustainable growth with no harm to environmental quality. I also compare and evaluate alternative policy combinations (i.e. taxes +subsidies) that correct two distortions from pollution and monopolistic competition. Finally, I find that, if the productivity of environment in final good production is not sufficiently enough, the number of clean goods tends to increase with more environmental concerns.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.399-408
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• 2016

There is a need to detect heteroscedasticity in a regression analysis; however, it invalidates the standard inference procedure. The diagnostics on heteroscedasticity may be distorted when both outliers and heteroscedasticity exist. Available heteroscedasticity detection methods in the presence of outliers usually use robust estimators or separating outliers from the data. Several approaches have been suggested to identify outliers in the heteroscedasticity problem. In this article conventional tests on heteroscedasticity are modified by using a sequential outlier detection methods to separate outliers from contaminated data. The performance of the proposed method is compared with original tests by a Monte Carlo study and examples.

• Journal of Korea Water Resources Association
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• v.37 no.11
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• pp.889-896
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• 2004

The fractal advection-diffusion equation (ADE) is a generalization of the classical AdE in which the second-order derivative is replaced with a fractal order derivative. While the fractal ADE have been analyzed with a stochastic process In the Fourier and Laplace space so far, in this study a fractal ADE for describing solute transport in rivers is derived with a finite difference scheme in the real space. This derivation with a finite difference scheme gives the hint how the fractal derivative order and fractal diffusion coefficient can be estimated physically In contrast to the classical ADE, the fractal ADE is expected to be able to provide solutions that resemble the highly skewed and heavy-tailed time-concentration distribution curves of contaminant plumes observed in rivers.

• The Journal of the Korea Contents Association
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• v.9 no.3
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• pp.262-269
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• 2009

The public and private sectors have quite different views on the operation of community welfare alliance. Their understanding of the issues has a vast difference, which may lead to twisted operation of the community welfare alliance. In fact, there are many areas that have troubles in the operation of the alliance. This study systematically analyzes limitations that the alliance has and it goals to draw out improvement policies to overcome them. As a study method, a survey is conducted on the leaders of community welfare alliance to suggest an AHP analysis model on the issue awareness and improvement policy. Concentrated on the analyzed results and implications entailed through the analysis, this study suggests improvement policies to overcome such limitations that the community welfare alliance has.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.3
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• pp.41-50
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• 1999

Derivatio of reasonable design floods was attempted by comparative analysis of design floods derived by Generalized Extreme Value(GEV) distribution using methods of L-moments and LH-moments for the annual maximum series at ten watersheds along Han, Nagdong. Geum, Yeongsan and Seomjin river systems, LH-coefficient of variation, LH-skewness and Lh-kurtosis were calcualted by KH-moment ration respectively. Paramenters were estimated by the Method of LH-Moments, Design floods obtained by Method of LH-Moments using different methods for plotting positionsi n GEV distribution and design floods were compared with those obtained using the Method of L-Moments by the Relative Mean Errors(RME) and Relative Absolute Errors(RAE). The results was found that design floods derived by the method of L-Moments and LH-Moments using Cunnane plotting position formula in the GEV distribution are much closer to those of the observed data in comparison with those obtained by methods of L-moments and LH-moments using the other formula for plotting positions from the viewpoint of Relative Mean Errors and Relative Absolute Errors. In viewpoint of the fact that hydrqulic structures including dams and levees are genrally using design floods with the return period of two hundred years or so, design floods derived by LH-Moments are seemed to be more reasonable than those of L-Moments in the GEV distribution.

• Water for future
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• v.24 no.4
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• pp.67-72
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• 1991

Various modeling approaches to study along term behavior of streamflow or groundwater storagge have been conducted. In this study, a Multivariate AR (1) Model has been applied to generate monthly flows of the one key station which has historical flows using monthly flows of the three subordinate stations. The Model performance was examined using statistical comparisons between the historical and generated monthly series such as mean, various, skewness. Also, the correlation coefficients(lag-zero, and lag-one)between the two monthly flows were compared. The results showed that the modeled generated flows were statistically similar to the historical flows.

• Korean Journal of Remote Sensing
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• v.14 no.1
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• pp.69-82
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• 1998

SAR imagery can overcome the limitations of electro-optical sensor imagery and provide us Information which plays a supplementary role. But it is necessary to remove a variety of geometric errors in SAR imagery. An accurate geometric correction of SAR imagery is not easy task to achieve, though some techniques and theories are introduced. We also have difficulties such as transformation problem between 'International' ellipsoid in Radarsat system and 'Bessel' ellipsoid. Two widely used correction method, one is made by simulated image, and the other by collinearity equation, usually use DEM. In this study, the merits and demerits of geocoding methods respectively and the effective method for Korean terrain were found.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.6-6
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• 2015

본 연구에서는 일단위로 제공되는 RCP 시나리오를 Poisson Cluster 기법을 활용하여 시간강우량으로 생성할 수 있는 모형을 개발하는데 목적이 있다. 일반적으로 시간단위 강우량의 경우 수자원 설계 또는 강우-유출 분석시 가장 기본이 되는 입력 자료로서 이에 대한 모의기법 확립이 기후변화에 따른 수문학적 영향 검토의 신뢰성을 결정짓는 핵심 요소이다. 그러나 국내 다수 연구를 살펴보면 기후변화 시나리오의 시 공간적 상세화 기법을 활용한 일단위 상세화 연구는 다수 존재하였지만, 일단이 이하의 시간적 규모에 대한 연구는 미진한 실정이다. 이러한 이유로 본 연구에서는 시단위 상세화 기법시 일반적으로 사용되고 있는 Poisson Cluster 기법을 활용하여 국내 실정에 맞는 시단위 상세화 기법을 개발고자 한다. 본 연구에서는 RCP 시나리오를 시단위강우량 자료로 생성하기 위해 다음과 같은 연구를 진행하였다. 첫째, 본 연구에서는 기상청에서 제공하는 RCP($27km{\times}27km$) 시나리오를 활용하였으며, 1km 격자 단위로 시공간적 상세화 기법을 수행하였다. 둘째, 시공간적으로 상세화 된 자료를 Poisson Cluster 기법을 기반으로 시간단위 자료를 생성하였으며, 기본적인 통계치(평균, 분산, 왜곡도 등)를 활용하여 관측값과 비교 분석 하였다. 마지막으로, 미래 기후변화 시나리오를 동일한 방법으로 시간단위 자료를 생성하고 연 최대값을 추출하여 빈도해석을 통해 미래 극치 확률강우량을 평가하였다. 본 연구 결과 시간단위 자료를 제공함으로써 미래 수자원 설계 및 영향평가를 효과적으로 수행할 것으로 기대되며, 수문기상변화 예측을 위한 신뢰성 있는 자료로 활용될 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.212-212
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• 2018

설계홍수량 산정요령(MLTMA, 2012)이 배포된 이후 실무에서는 홍수량을 산정할 때, Clark 단위도(Clark, 1945)를 적용하는 것으로 획일화되는 추세다. SCS 단위도(SCS, 1972)가 설계홍수량 산정요령에서 배제된 것은 Clark 단위도와 비교해서 도달시간 등 유역 매개변수를 같게 대입하더라도 홍수량이 과다 산정되는 경향 때문이다(e.g., Singh, 2000; Kilduff et al., 2010; Bhunya et al., 2011). 그럼에도 불구하고 SCS 단위도는 단변량 모형으로 적용 방법이 매우 간단하고, 실무에서 주로 사용되는 상용프로그램 대부분에 내재되어 있는 등 실무에서의 효용가치가 높은 편이다. SCS 단위도의 높은 첨두홍수량을 조정하고자 첨두시간 산정 공식을 수정한 SCS 방법이 제안되었으나(e.g., Ministry of Construction, 1992; Jung and Moon, 2001), 이는 첨두시간이 크게 산정되도록 하여 첨두홍수량을 낮추려는 시도로 도달시간, 기저시간 등 유역의 물리적인 특성을 왜곡한다. 반면에 SCS 단위도의 기울기(Peak Rate Factor; PRF)는 유역 경사에 따라 300에서 600 사이의 값을 갖게 되고 평균값으로 484가 제안되었으나(SCS, 1972), 이를 맹목적으로 사용하기에는 무리가 있다. 실험을 통해서 75-100, 284, 100-575 등 다양한 범위의 PRF 값이 제시되었고(e.g., Woodward et al., 1980; Wanielista et al., 1997), PRF에 직접 비례해서 첨두홍수량이 결정되는 SCS 단위도의 특성을 고려할 때, 유역의 조건에 맞는 적절한 PRF를 산정하는 것이 우선이다. 본 연구에서는 SCS 단위도의 첨두시간과 같은 종속변수 대신 PRF를 조정하는 방법에 주목해서 Clark 단위도로 산정된 홍수량과 서로 상호보완이 될 수 있도록 국내의 유역 환경에 적합한 SCS 단위도 적용 방안을 제시하고자 한다.