• 제목/요약/키워드: restricted choice

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Analysis of Consumer Preference on Mid to Long Term Power Sources by Using a Choice Experiment (선택실험법을 이용한 중장기 전원별 소비자 선호 분석)

  • Jung, Heayoung;Bae, Jeong Hwan
    • 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.

Dynamic Behaviors of Redox Mediators within the Hydrophobic Layers as an Important Factor for Effective Microbial Fuel Cell Operation

  • Choi, Young-Jin;Kim, Nam-Joon;Kim, Sung-Hyun;Jung, Seun-Ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.4
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    • pp.437-440
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    • 2003
  • In a mediator-aided microbial fuel cell, the choice of a proper mediator is one of the most important factors for the development of a better fuel cell system as it transfers electrons from bacteria to the electrode. The electrochemical behaviors within the lipid layer of two representative mediators, thionin and safranine O both of which exhibit reversible electron transfer reactions, were compared with the fuel cell efficiency. Thionin was found to be much more effective than safranine O though it has lower negative formal potential. Cyclic voltammetric and fluorescence spectroscopic analyses indicated that both mediators easily penetrated the lipid layer to pick up the electrons produced inside bacteria. While thionin could pass through the lipid layer, the gradual accumulation of safranine O was observed within the layer. This restricted dynamic behavior of safranine O led to the poor fuel cell operation despite its good negative formal potential.

Analysis of a New Current-Fed DC-DC Converter with the Double Outputs (이중출력을 갖는 새로운 전류환류형 DC-DC 컨버터의 해석)

  • Hong, S.M.;Kim, C.S.;Kim, H.J.
    • Proceedings of the KIEE Conference
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    • 1997.07f
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    • pp.2033-2036
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    • 1997
  • In this paper, we proposed a novel current-fed DC-DC converter with multi-output. It has two winding reactor in series with the input source of the converter. By using the 2nd winding recycling the energy stored in the reactor to the input, the double-outputs DC-DC converter can be created, which makes it a good choice for a multi-output power supply with more outputs and has savings in cost and space. The steady state and dynamic characteristics of the converter are analyzed in detail by using the state space averaging method. It is found that the maximum value of $V_{o2}$ exists in the 2nd output and also during the MOSFET off period, the energy stored in the magnetizing inductance is reset through auxiliary winding $N_3$, so the duty cycle is restricted to 50%. Theoretical and experimental results were taken from the converter rated at switching frequency 50kHz. input voltage 50V. output voltage 5V. 12V and output power 65W. As a result, both results were well consistent. Therefore, it is varified the validity of the proposed converter in this paper.

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A Study on the System Improvement for the Activation of Industrial Man Power in Fisheries (수산업계 산업기능요원제도의 활성화를 위한 개선방안 연구)

  • Kim, Yong-Bok;Kim, Jong-Hwa
    • Journal of Fisheries and Marine Sciences Education
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    • v.13 no.2
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    • pp.178-193
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    • 2001
  • This paper is written for the aim of the system improvement to the activation of industrial man power in fisheries on the basis of '73 military special except system (MSES). As the results of the purpose, several points to be improved are as follows : 1. It is necessary to reminder on the important of man power maintenance by the cooperative system between industry and school. 2. MSES should be known to the people broadly and positively through the Korea pelagic fishery association and related industry, for example, their internet homepages. 3. The students should be opened the choice opportunity to applicant to lower license grade than their general study level. 4. More companies will be relaxed the restricted items upon new criteria about the nominated companies, revised system on March 27, 2001. 5. If any nominated company has unemployed man power under the system, it entrust the power of attorney in military office to other recommended authority or association for the purpose of the prompt performance to other nominated companies.

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Analysis of the Statistical Techniques and Errors in the Field of Sasang Constitution Researches: from 2011 to 2015 (최근 5년간(2011~2015) 사상체질분야 논문의 통계기법 분석 및 오류에 관한 연구)

  • Kim, Sujung;Kim, Sanghyuk;Lee, Siwoo
    • Journal of Sasang Constitutional Medicine
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    • v.28 no.1
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    • pp.51-56
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    • 2016
  • Objectives This study was to identify the types of errors in the statistical analysis and trends of previous reported papers that used various statistical techniques.Methods We have selected 118 original articles for statistical review from the OASIS(http://oasis.kiom.re.kr) and the Pubmed(http://www.pubmed.gov) in the field of Sasang constitutional medicine. Published year was restricted from 2011 to 2015.Results 1. The ANOVA(25.72%) was the statistic of choice overall, followed by the chi-square test(21.74%), regression analysis(14.13%), t-test(11.59%), and etc. 2. By examining the errors of the statistical methods, there were 42(59.2%) thesis with errors among 71 thesis using ANOVA, 19(31.7%) thesis among 60 thesis using chi-square test, and 35(89.7%) over 39 thesis using regression analysis.Conclusions To improve the quality of Sasang Constitution, the participation of statisticians in research design will reduce the significant errors in statistical interpretation of the results.

Valuing the Economic Benefits of the Water Quality Improvement in Busan (부산시 수돗물 수질개선 편익의 추정)

  • Kwak, So-Yoon;Yoo, Seung-Hoon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.452-456
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    • 2010
  • Water is an indispensable input to human's existence and industrial production. In these days, people are getting more concerned about their health and the interest in the safety of drinking water has increased. In this situation, this paper attempts to measure the economic benefits of the tap water quality improvement. The study area was restricted to Busan, the second largest city in Korea, where local government is planning to implement a tap water quality improvement program. We apply a one-and-one-half bounded dichotomous choice contingent valuation (CV) method to obtain at least a preliminary evaluation of the benefits. CV is developed for valuing goods or services that cannot be valued either directly or indirectly from market observations and has been applied to several environmental goods. The CV survey was rigorously designed to comply with the guidelines for best-practiced CV studies. We surveyed a randomly selected sample of 400 households in Busan and asked respondents questions in person-to-person interviews about how they would be willing to pay for the water quality improvement. Respondents overall accepted the contingent market and were willing to contribute a significant amount (US$1.66), on average, per household per month. We can also calculate the aggregate value of the program which improves the water quality in Busan. This study is expected to provide policy-makers with useful information for evaluating and planning environmental policies relating specifically to water.

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A Survey on the Korean Food Preference, Frequency and Nutritional Knowledge of College Students in Kangwondo Area (강원지역 일부 대학생들의 한국음식섭취와 영양지식 조사)

  • Park, Ok-Jin;Min, Sung-Hee
    • Journal of the Korean Society of Food Culture
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    • v.19 no.1
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    • pp.43-51
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    • 2004
  • The purpose of this study was to investigate the preference on Korean food and the nutritional knowledge of the college students. Self-administrated questionnaires were completed by 556 college students majoring food-related subjects in Kangwon-do area. The results were as fellows : 1. Male subjects liked meat (Calbi, Bulgogi, Seolungtang) and female subjects liked Kimchi and soybean soup. Both genders, however, disliked seasoned vegetables. 2. In the frequency of taking, Kimchi had the highest rank followed by Bibimbab and Seolungtang in higher order. 3. The first choice of both family and friends eating out was Korean foods. 4. The top two reasons for selecting Korean foods were their deliciousness and availability in higher order. 5. According to this study, the establishment of standardized recipe and the different way of facing Korean foods of individuals (Koreans) are promptly required for the globalization of Korean foods. 6. The nutritional knowledge of the subjects were limited and restricted to simple facts regardless of their major.

A Study on the Art Make-up Reflected on Grotesqueness -Focused on face- (그로테스크 특성이 반영된 예술 분장의 연구 - 안면 분장을 중심으로 -)

  • Kim, Soong-Hyun
    • Journal of the Korean Society of Fashion and Beauty
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    • v.3 no.2 s.2
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    • pp.39-46
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    • 2005
  • Art-Make-up has resulted in occupying one of the central areas of this culture. Art Make-up is currently undergoing various changes. The viewpoint of modern make-up is the infiniteness of emotion such as the subjectively individualized expressions and aesthetic values breaking with conventional thought. The most significant change is the idea of the 'grotesque'. The purpose of this research is to re-clarify the development of the diversity, professionalism and artistic feature through the study of Art make-up based on the 'grotesque' style. This also strives to focus attention at observing the deep and mysterious workings of the human inner world. In order to explain the features of 'grotesque' Art make-up, six images below are presented. Firstly, Inharmonious images. Secondly, disgusting inhuman images. Thirdly, mechanical images. Fourthly, distorted and exaggerated images. Fifthly, diabolic and horrific images. And, lastly, playful images. These six images thoroughly demonstrate the 'grotesque' features. The fact at we can see the 'grotesque' features in Art make-up explains the enormous growth of Art make-up and the unlimited range of expression in this field. It also implies that the choice of material and theme is not restricted to universal artistic criteria. In closing, it is necessary that Art make-up is thought of not as actual art but more as a tool for its subjects. As a result, this research will provide valuable information for studies in the future.

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An Improved Algorithm for Performance Evaluation of Communication Protocol Using Extended Timed Petri Nets (확장된 Timed Petri Net을 이용한 통신 프로토콜의 성능분석 알고리즘)

  • 이철희;이상호;김홍식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.14 no.3
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    • pp.197-206
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    • 1989
  • In this paper, we represent an improved algorithm of performance evaluation for communication protocol. It is an algorithm that analyzes Extended Timed Perti Net models including time which have been successfully used to model and evaluate the performance of distributed system. While Timed Petri Nets generally limted to free-choice and safe nets, our algorithm permits the construnction of elegant models of restricted concurrent processing. Furthermore, to reduce the state space size of Timed Reachability Graph, we improve the algorithm by using Maximum Firing Rule and sets of simultaneously firing transitions. Procedures for constructing of Timed Reachability Graphs and analyzing are presented, and we demonstrate the usefulness of this algorithm by applying it to the analysis of the communication protocol.

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Seismic evaluation and upgrading of RC buildings with weak open ground stories

  • Antonopoulos, T.A.;Anagnostopoulos, S.A.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.611-628
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    • 2012
  • The inelastic earthquake response of existing, reinforced concrete buildings with an open ground story, designed according to the old Greek codes, is investigated before and after their seismic strengthening with steel braces restricted to the open ground stories. The seismic performance evaluation is based on Part 3 of Eurocode 8 for assessment and retrofitting of buildings. Three and five-story, symmetric and non-symmetric buildings are subjected to a set of seven pairs of synthetic accelerograms, compatible with the design spectrum, and conclusions are drawn regarding the effectiveness of the strengthening solutions. Seismic behavior of the selected models confirms results of previous work regarding the insufficient capacity of the open ground stories for design level earthquakes. It is also shown that strengthening only the weak ground story, a choice having the substantial advantage of low cost and continued usage of the building during its seismic retrofitting, can remove the inherent weakness without shifting the problem to the stories above and thus making such buildings at least as strong as those without a weak first story. This partial strengthening is possible for symmetric as well as eccentric buildings, in which torsion plays a further detrimental role.