• Environmental and Resource Economics Review
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• v.21 no.4
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• pp.921-945
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• 2012

Conditional Logit (CL) model is widely used since its model estimation and interpretation of results of the model is relatively easy, on the other hand, it has the limit of preference heterogeneity of respondents being not fully considered. In this study we used the two models, Mixed Logit (ML) Model and Latent Class Model (LCM) to explain preference heterogeneity of respondents for protection for Boryeong Dam wetland. As a result of the examination for heterogeneity in Boryeong city and six metropolitan areas, we found there was significant difference between two regions. While there was explicit preference heterogeneity within respondents in Boryeong city, we found little heterogeneity within respondents in six metropolitan areas. Thus in the case of six metropolitan areas, CL model can be used for parameter estimation while in the case of Boryeong city, WTP estimates are based on parameter estimates from ML model to reflect the heterogeneity within respondents. Additionally, ML model with interaction and 2-class LCM for respondents in Boryeong city were used to explain the sources of the heterogeneity. The ML model with interaction has advantage of explaining individual unobserved heterogeneity. However The comarison between these two models reflects the fact that LCM provided added information that was not conveyed in the ML model with interaction. Thus, Preference heterogeneity within respondents in this study may be better explained by class level through LCM rather than indiviual level through ML model.

• Environmental and Resource Economics Review
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• v.27 no.4
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• pp.695-723
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• 2018

Recently, extreme weather due to climate change has become more frequent, and increase of fine dust has worsen air quality in Korea. Therefore, not only negative perception on coal-fired power generation is dominant, but also the social acceptance of nuclear power generation declines. This study aims at deriving consumer preferences on the mid and long term power mix with various energy sources. Willingness to pay for each generation source was estimated and the preference heterogeneity of consumers was examined by using mixed logit and latent class models. Mixed logit estimation results show that the preference heterogeneity of consumers is especially large for the nuclear power relative to renewable or coal energy. According to the estimation results from the latent class model, group 1 prefers renewable energy while group 2 prefers coal energy. Group 3 shows lexicographic preference which means restricted rationality. As for the policy implication, it is necessary to understand the preference heterogeneity of consumer groups in planning the mid to long term power mix.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.357-366
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• 2013

This study investigates to explain preference heterogeneity of respondents for economic valuation in washland of Upo wetland using Mixed Logit Model and Latent Class Model. Mixed Logit Model showed respondent heterogeneity in the attributes of wetland area and funds as well as some alternatives violated IIA assumption. 2-class Latent Class Model for respondents were used to explain the sources of the heterogeneity. Class 1 respondents who are located relatively close to Upo wetland had more experience and knowledge of Upo wetland and better understood the information suggested in the questionnaire than class 2 respondents in mostly metropolitan area of Seoul, Incheon.

• Environmental and Resource Economics Review
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• v.16 no.4
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• pp.873-900
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• 2007

Non-market valuation studies tend to assume that individual households have homogeneous preferences for a non-market good to value. However, since the preferences for non-market goods, especially environmental goods are more likely to be heterogeneous by nature, it may be more appropriate to assume heterogeneous preferences for non-market goods, which may in turn may lead to reduced biases in the WTP estimation. This study investigate the extent to which individual households have heterogeneous preferences for reduced concentrations of radon, a radioactive indoor air pollutant, for road safety, and for nuclear power safety. We also analyze the effect of heterogeneity assumption on the results of model and WTP estimation. Using the choice experiments and mixed logit models, we found that allowing for heterogeneous preferences improved model fitness and that there existed heterogeneous preferences for both reduced radon concentration and road safety, albeit not for nuclear power safety. The mean WTP for reduced radon concentrations and road safety increased by factors of 2.44 and l.74 respectively with the models allowing for heterogeneous preferences.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.247-253
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• 2006

본고는 주요 댐호수의 휴양가치를 댐호수의 특성별로 도출하고자 실제로 댐호수를 선택한 행위를 분석하고, 아울러 선택실험을 통해 가상적으로 설정된 특성을 가진 댐을 방문할지를 선택하도록 하여 그 결과를 분석하기도 하였다. 또한 현시선호된 선택과 진술선호선택을 모두 결합하여 분석하는 기법도 사용하였다. 분석결과 진술선호자료와 현시선호자료간의 이질성이 상당한 것으로 나타났으나 두 자료를 결합함으로써 모든 특성변수들이 만족도에 미치는 영향이 직관과 부합되도록 도출되었다. 댐호수의 수량과 수질 모두가 레크리에이션 가치에 영향을 미치는 것으로 나타났으나, 특히 수질개선의 편익 증가효과가 매우 크다는 것이 확인되었다. 그 외에도 홍보관, 주변 숙박시설 및 음식점, 인근 휴양지와의 연계성 등도 휴양가치 증가에 영향을 미치는 주요 변수로 파악되었다.

• Korea Trade Review
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• v.43 no.4
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• pp.69-88
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• 2018

Using a panel data set covering 19 Korean manufacturing sectors for the period 2009-2015, this paper investigates the extent to which industry characteristics affect the mode of entering foreign markets. The estimation results across various specifications show that firms prefer affiliate sales to export as firm heterogeneity increases, implying positive effects of productivity regarding foreign relative to domestic operations. The motive for overseas production is reinforced as economies of scale at the plant level decrease and economies of scale at the corporate level increase.

• Journal of Korean Home Economics Education Association
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• v.24 no.4
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• pp.1-18
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• 2012

This study investigated the mate selection preferences of single female teachers by investigating the desired traits in socioeconomic, physical attractions, psychological traits and family roles of their prospected marital partner, in order to explore the current trends in homogamous marriage. A questionnaire was distributed to 295 unmarried female teachers selected by convenience sampling from the various cities. The teachers pursued homogeneity in age, educational attainment, religion, and occupation while they preferred partners with higher income level. In terms of physical assets, the attraction that the teachers felt towards the partner was the most important physical appearances. The respondents preferred partners who are masculine and an androgynous partner. The teachers held high expectations towards their future spouses in that they desired to share the roles of emotional, financial support, child care and kin keeping. A partner who shared modern sex role attitudes was preferred over someone who held traditional one. The pursuit for overall homogeneity reflects that the teachers seek for equality in their relationships with prospected marital partners by exchanging similar characteristic.

• Environmental and Resource Economics Review
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• v.30 no.1
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• pp.49-77
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• 2021

This study uses a choice experiment approach to examine whether different types of feedstocks as well as other attributes such as the cost of bioethanol, bioethanol blending ratio, and government support policies affect consumers' biofuel preferences. We apply a standard conditional logit model, a mixed logit model (MLM), and individual coefficient estimation model (ICM) to estimate the parameters of the investigated attributes. The results show that people prefer domestic and non-food feedstock, along with tax exemption as a support policy. All the attributes show unobservable preference heterogeneity in the MLM and ICM. In particular, willingness to pay for attributes are higher in the genetically modified (GM) feedstock-unknown group than in the known one. We show the importance of using domestic and non-food feedstocks and managing GM feedstocks carefully to avoid consumer resistance when producing bioethanol in South Korea.

• The Korean Journal of Ecology
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• v.23 no.3
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• pp.255-266
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• 2000

생물권보전지역으로 지정된 점봉산의 온대낙엽수림(참나무 성숙림)에서 임상초본식물의 공간분포를 정량화하고, 이들의 공간분포에 미치는 미소환경요인의 영향을 파악하였다. 대부분의 임상초본식물들은 영구 방형구내 미소지소간에 큰 변이를 나타내었다. 초봄에 출현하는 임상초본식물중 공간의존도가 높은 식물은 현호색, 애기나리 및 노랑제비꽃이었고, 가을에 출현하는 임상초본식물중 공간의존도가 높은 식물은 벌깨덩굴, 쌀새 및 도라지모시대이었다. 초봄에 출현하는 홀아비바람꽃과 얼레지 그리고 가을에 출현하는 도라지모시대와 쌀새의 공간의존거리가 상대적으로 짧은 편이었다. 초봄에 출현하는 노랑제비꽃, 애기나리 및 얼레지는 관목이 적고, 낙엽층이 얇으며,토심이 깊고, 토양수분함량, 유기물함량 및 염기성양이온함량이 상대적으로 적은 생육지를 선호하였고, 애기앉은부채 와 현호색은 관목이 밀집하고, 낙엽층이 두꺼우며, 토심이 얇고, 유기물함량, 토양수분함량 및 영양염류함량이 높은 생육지를 선호하였다. 오리방풀은 빛조건이 좋고, 낙엽층이 두꺼우며, 토양수분함량과 영양염류가 풍부한 생육지를 선호하였고, 단풍취, 대사초, 개별꽃, 참취, 쌀새 및 도라지모시대는 토심이 깊고, 낙엽층이 얇으며, 토양수분함량과 영양염류함량이 상대적으로 적은 생육지를 선호하였다. 본 참나무 성숙림에서 토양수분함량, 유기물함량 및 영양염류함량은 바람, 미소지형 및 관목의 밀집정도에 의해 공간적으로 재배치되는 낙엽층 두께에 의해 영향을 받고 있기 때문에 초봄과 가을에 관찰되는 임상초본식물의 공간분포는 낙엽층의 불균등한 분포에 의해 가장 큰 영향을 받고 있는 것으로 추정되었다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.890-900
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• 1999

In homogeneous multiprocessor systems, the task allocation algorithm which equally assigns tasks to processors if possible is generally used. But this algorithm is not suitable to accomplish to accomplish effective task allocation in heterogeneous multiprocessor systems. JSQ (Join the Shortest Queue) algorithm is often used in heterogeneous multiprocessor systems. Unfortunately, JSQ algorithm is not efficient when the differences of capabilities of processors are far large. To solve this problem, we suggest a heuristic task allocation algorithm that makes use of dynamic information such as task arrival time, task service time, and number of finished tasks. The results of simulation show that the proposed heuristic allocation algorithm improves the system performance.