• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.415-422
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• 2018

Lycorma delicatula, known as spotted lanternfly, is a planthopper native to Southeast Asia, including Vietnam, India and South China. This species damages local fruit trees and has spread rapidly in South Korea in recent years. The purpose of this study is to present the methods and estimation results pertaining to the risk of invasive species like Lycorma delicatula. We used a partial budget (PB) method to assess direct income reduction of farm households and a partial equilibrium (PE) model to examine social welfare change from the outbreak of Lycorma delicatula. We also estimated the future economic impacts of Lycorma delicatula under various climate scenarios considering habitat suitability. As climate change progresses, domestic ecosystems are expected to become increasingly vulnerable to pest outbreaks leading to further economic damage. We believe that this study can be a base to evaluate efficiency of the national pest control and quarantine system.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.215-229
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• 2018

The purpose of this study was to examine the structural relationships among factors affecting teachers' robot-based SW education acceptance in primary school. In addition, this study investigated moderating effects of gender, age, and experience. For this purpose, 171 elementary school teachers participated in this study and structural equation modeling analyses were employed to examine the causal relationships among variables. The result of this study showed that perceived ease of use, perceived usefulness, personal innovativeness had direct effects on attitude. Furthermore, attitude mediated relationships between perceived usefulness, perceived ease of use, personal innovativeness and intention to use. Third, the moderating effects of experience between perceived usefulness, personal innovativeness and attitude were significant, but gender and age were not significant on all paths. Based on the results of this study, successful teaching practices, cases, and contents should be shared with teachers. Also, continuous supports and differentiated strategies based on experience are needed.

• Journal of Korea Water Resources Association
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• v.48 no.8
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• pp.625-634
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• 2015

The diverse patterns of separation zone according to the marked bed discordance by dredging at confluence in addition to the confluence angle of tributary and discharge ratio between tributary and main channels have been analyzed by CCHE2D model simulation. The separation zone is defined by inside of zero velocity boundary at down-stream of confluence. The separation zone dose not formed at the $30^{\circ}$ of confluence angle of tributary. The size of separation zone increases as the discharge ratio and confluence angle increase in general. The separation zone decreases as the dredging depth increases which shows the relative momentum reduction compared by the flow volume increasing by dredging at confluence. The contraction factor with the variation of confluence angle and discharge ratio has been investigated and confirmed the corresponding conveyance decreasing results in backwater effect. The regression equation of shape factor with confluence angle and discharge and dredging depth ratios has been suggested.

• KDI Journal of Economic Policy
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• v.9 no.2
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• pp.71-88
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• 1987

본고(本稿)에서는 소비지출(消費支出)을 상이(相異)한 가구특성(家口特性)을 지닌 단위가구(單位家口)의 소비지출(消費支出)로 환산(換算)하기 위한 지수(指數)(디플레이터), 즉 상이(相異)한 가구특성(家口特性)들을 지닌 도시가구(都市家口)의 동등화소비단위(同等化消費單位)를 추계(推計) 분석(分析)하였으며 이를 위하여 "조르겐슨-슬레스닉"의 모형(模型)을 적용(適用)하였다. 특징적(特徵的)으로 나타난 결과는 다음과 같다. 첫째, 품목별(品目別) 동등화소비단위(同等化消費單位)나 총화(總和) 동등화소비단위(同等化消費單位) 모두 가구주(家口主) 직종별(職種別)로는 일용근로자(日傭勤勞者), 자영업자(自營業者), 봉급자(俸給者)의 순서로 높아지고 가구원수(家口員數)는 3명(名)에서 4명(名)으로 느는 데 따라 크게 증가되고 있다. 둘째, 가구원수(家口員數)의 증가(增加)에 따른 동등화단위(同等化單位)의 증가와 일관성 있게 가구주(家口主) 연령별(年齡別)로는 자녀(子女)를 한두 명 두게 되는 25~29세(歲)의 연령층(年齡層)에 유의(有意)한 동등화단위(同等化單位)의 증가가 있는 것으로 나타났다. 셋째, 지출항목별(支出項目別)로는 광열비(光熱費)와 수도료(水道料)를 제외한 모든 지출비용(支出費用)에서 소비생활(消費生活)에 있어서 규모(規模)의 경제(經濟)가 나타난 바 이러한 광열비(光熱費)와 수도료(水道料)의 추정결과(推定結果)는 우리나라에 있어서 누진적(累進的)인 요율체계(料率體系)에서 기인(基因)한 것으로 해석된다. 이 연구(硏究)가 함축하는 가장 큰 정책적(政策的) 의미(意味)는 일용근로자가구(日傭勤勞者家口)의 동등화소비단위(同等化消費單位)가 가장 낮음으로써 같은 수준의 경제성장률(經濟成長率)을 전제하더라도 이들에게 소득(所得) 및 소비(消費)의 증대(增大)가 일어나면 국민경제(國民經濟) 전체로서의 복지후생수준(福祉厚生水準)이 가장 크게 향상될 수 있음을 함축하고 있는 데 있다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.163-176
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• 1993

A methodology based on the influence coefficient algorithm was established for the optimal calibration of QUAL2E reaction coefficients. It was applied to the stream sections from the Chungju Dam to the downstream end of the South Han River. A water budget analysis using the monthly records of reservoir inflows and outflows in 1990 was made to determine tributary inflows. Estimated tributary inflows were used, together with the monthly records of water quality measurements in 1990, for the calibration of reaction coefficients. Simulated quality constituents were chl.a. nitrogen cycles, phosphorus cycles. BOD and DO. A sensitivity analysis was made to determine significant reaction coefficients, and as a result 11 reaction coefficients were selected as calibration parameters. The influence coefficient algorithm applied to the calibration of QUAL2E reaction coefficients proved to be a useful one yielding a rapid convergence. Each calibration parameter converged to an optimum value within 3 iterations.

• Management & Information Systems Review
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• v.34 no.2
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• pp.21-37
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• 2015

Entrepreneurship and innovation are highlighted as a way to overcome limitations and risk factors caused by today's uncertain business environment. As the uncertainty in the business environment increases, organizations are required to adapt to ever changing business dynamics. For this adaptation, entrepreneurship and innovation are crucial factors. This study proposes a model to explain a structural relationship between entrepreneurship, technological innovation, and innovation performance. The unit of analysis focus is small and medium-sized businesses. Empirical results show that there are positive causal relationships from entrepreneurship to technological innovation, and from technological innovation to innovation performance. Additionally, no direct relationship from entrepreneurship to innovation performance can be achieved through innovation activities such as technological innovation. This study points out the importance of entrepreneurship and technological innovation, and suggests that entrepreneurship along with technological innovation should be internalized as business practices leading to increased performance.

• 한국벤처창업학회:학술대회논문집
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• 2006.11a
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• pp.197-217
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• 2006

Korea economy's latent growth rate has already been decreased about 4%. During 1983-1989, the latent growth rate was 8%, before the foreign exchange crisis, 1990-1997 was 6.7%, and during $2000{\sim}2004$, it had been decreased 4.4%. The latent growth rate means economy growth rate which one nation can achieve capital, labor, and factors as applying these. Our economy growth rate was 8% in 1980s, but it had been decreased about 6.7% during $1990{\sim}1997$, after 2000, it remarkably decreased 4.8% which shows weakness of our economy's strength. This study attempts to investigate about export growth factor of venture company in our nation's growth that depends on export. This thesis studied the companies continuance and growth in external environment's regular correlation and casual relationship which surround company's factors and internal. Also, the external environment, which surrounds company, can be thought that company can't control itself, so that the company's continuance and growth can be decided because of its internal primary factors. This thesis establishes and analyzes the study model that how factors can affect to company's growth.

• Water for future
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• v.29 no.2
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• pp.179-190
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• 1996

The characteristics of water quality in the downstream of the Han River were analyzed by statistical techniques. Basic characteristics, areal and temporal variations, and correlations of water quality data were investigated. Monthly water quality data have been investigated systematically by exploring data analysis, including time series plot, summary statistics, distribution test, time dependence test, seasonality test and flow relatedness test. Results show that water quality data in this river have seasonality. And applicability of stochastic models such as Thomas-Fiering model and ARMA(1,1) model was identified. From the examination of water quality data related to discharge, it was found that DO and SS are sensitive to water temperature rather than discharge, while BOD and COD are sensitive to discharge at dry seasons. Seasonal periodicities were identified in all water quality variables from the cross correlation analysis.

• Environmental and Resource Economics Review
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• v.24 no.1
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• pp.165-187
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• 2015

In this paper, we tested if the sewage subsidy from Korean Water Management Fund discourage sewage fee increase by Korean local governments, and consequently hinder water quality improvement. To examine this counter-incentive effect of Water manage Fund sewage subsidy, we estimated the effect of sewage subsidy on the ratio of sewage fee revenue to environmental treatment facilities' operation cost of local governments in 2009-12, using two-stage least square estimation. We found that the sewage subsidy has negative effect on the sewage fee revenue to sewage operation cost ratio. But, the statistical significance of this effect was sensitive to model specification. And the size was too small to conclude that the counter-incentive effect was economically significant.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.301-314
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• 2008

The purpose of this study is to examine the effect of information service quality on user satisfaction and individual performance in Outbound Callcenter. A survey was conducted and data were collected from 330 respondents of 1 company which adopted CMS. Validity and reliability of the research instrument were tested and research hypotheses were examined using PLS Graph 3.0. As a result of data analysis, 6 out of 8 hypotheses were supported. User satisfaction is significantly influenced by information quality factors such as accuracy, currency, and relevancy. 2) Also, User satisfaction is significantly affected by internal service quality factors such as training support and reward system. 3) Individual performance is significantly influenced by user satisfaction. Implications of these findings are discussed for researchers and practitioners.