• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.29-38
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• 2008

This study intends to analyze the value of school forests, one type of urban forest. For this purpose, four attributes of school forests were investigated, considering ecological, educational, social and economic values using a conjoint model as the stated preference. Based on literature reviews, the levels of the four attributes were selected, and a questionnaire survey was given to 279 urban residents divided into 2 groups: those impacted by school forests and those not. The study results suggest that the most important attribute of school forests is economic value, and next is ecological, social and educational value according to the part-worth model. The fitness level of the model is 0.900(total group) which is very significant. As for the economic value, free and 1,000 won are more critical factors than the other 2 levels, 5,000 won and 10,000 won and air pollution purification and making the school landscape are more critical factors than small habitats and microclimate factors. In addition, regarding the social value related to residents' leisure activities，the utility of nature observation is higher than walking and exercising. Finally, for educational value, understanding nature's importance is more critical than the emotions and learning of students. The estimated WTP per household/month is 3,580 won, the group related to school forestsis 3,650 won and the non-related group is 3,540 won. Based on these results, the estimated total economic value of all households per year is 6,820 hundred million won. The group related to school forests is 6,970 hundred million won and the non-related group is 6,750 hundred million won.

• Environmental and Resource Economics Review
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• v.29 no.3
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• pp.335-362
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• 2020

Using the Hedonic pricing model using Box-Cox transformation, this paper estimated the marginal effect (implicit price) of odors from landfill in the metropolitan area on housing prices and the willingness to pay for changes in certain odor conditions. This paper utilized the proximity from the landfill in the metropolitan area as a environmental variable, and analyzed the effect of various housing characteristic variables on the sale price of apartments within a radius of 5 km from the landfill. In particular, because odors factor have various heterogeneity, we applied hedonic price models instead of stated-preference methods with various types of functional forms through Box-Cox transformation, considering the heterogeneity of each region. Estimates show that the marginal value (implicit price) for the distance from the odor source was 0.227 to 0.533 depending on the function type of the estimated model. In addition, when other house factors are the same, the marginal willingness to pay for a distance of 1km from the odor source was calculated to be 16.79 to 51.76 thousand dollar depending on the type of function. Finally for the general Box-Cox model, the annual WTP was estimated to be 3,229dollar.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.6
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• pp.79-86
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• 2009

In this paper, it has the performance metrics and the utility evaluation of the collusion codes about multimedia fingerprinting code based on BIBD and then the tracing algorithm of all colluders is proposed. Among the collusion codes, the bit stream of "all 0" or "all 1" are generated, also same collusion code and bit reversed code with user's fingerprinting code are generated. Thus there was occurred some problems, in which a colluder is deciding to anti-colluder or anti-colluder is deciding to colluder. In this paper, for the performance metrics and the utility evaluation of the collude codes, the experiment onto the total solution is processed by the logical collusion operation added with a partially processed averaging attack in the past papers. The proposed performance metrics and the utility evaluation about the collusion code generated from multimedia fingerprinting code based on BIBD is operated. Through the experiment, it confirmed that the ratio of colluder tracing is 100%.

• Clinical and Experimental Pediatrics
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• v.52 no.11
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• pp.1249-1259
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• 2009

Purpose:From a societal perspective, we evaluated the cost-effectiveness of a novel sustained-release injection of recombinant human growth hormone (GH) administered on a weekly basis compared with that of the present daily GH injection for the treatment of children with GH deficiency. Methods:Health-related utility for GH therapy was measured based on the visual analogue scale. During July 2008, caregivers of 149 children receiving GH therapy form 2 study sites participated in a web-based questionnaire survey. The survey required the caregivers to rate their current subjective utility with daily GH injections or expected utility of weekly GH injections. Because there was no difference in the costs of the daily and weekly therapies, for the purposes of this study, only drug acquisition costs were considered. Results:Switching from daily to weekly injection of GH increased the utility from 0.584 to 0.784 and incurred an extra cost of 4,060,811 Korean won (KW) per year. The incremental cost-utility ratio (ICUR) for a base case was 20,305,055 KW per quality-adjusted life year (QALY) gained. Scenario analyses showed that the ICUR ranged from 15,751,198 to 25,489,929 KW per QALY. Conclusion:The ICUR for a base case and worst case scenario analyses ranged from 0.85 to 1.37-times per capita gross domestic product of Korea, which is considered to be within the generally accepted willingness-to-pay threshold. Thus, it is concluded that switching from daily to weekly injection of GH would be cost-effective.

• Defense and Technology
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• no.8 s.246
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• pp.30-39
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• 1999

재래식 잠수함의 잠항 능력을 향상시키기 위해 제안된 AIP 장치들도 끊임없는 기술의 진보와 경쟁 그리고 실선 적용에 의한 검증을 거쳐 미래에는 어느 한 AIP 장치가 표준으로 자리잡게 될 것으로 추측된다. 시스템 자체의 소음수준이 낮을 것으로 기대되는 연료전지 AIP도 많은 홍보와 관심 속에서 실선용이 개발 중이다. 하지만 모든 AIP 장치들이 제각기 고유의 비효용성을 갖고 있는 것처럼 연료전지 역시 안전성 저하를 비롯한 여러 가지 부담을 추가한다는 점에 유의해야 할 것이다.

• The Korean Journal of Financial Management
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• v.18 no.1
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• pp.157-174
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• 2001

본 연구에서는 기업의 증자와 관련하여 풍문설이 유포되었을 때 그에 대한 조회공시의 내용을 확인, 부인, 혹은 검토의 유형별로 나누고, 사건연구방법을 사용하여 공시의 정확성과 효용성(정보전달 효과)을 살펴보고, 공시가 적시성이 있는지를 살펴보았다. 본 연구의 실증분석에 따르면 조회공시는 대체적으로 효율적이지 못하다고 결론지을 수 있다. 우선 공시의 적시성에 있어서는 조회 공시일 이전에 주가 수익률이 급격하게 상승함으로 미루어 증권시장에 풍문이 난무하여 공시가 충분히 신속하지 않았다고 할 수 있다. 공시의 정확성과 그 효용성 측면에서 보면 부인공시 후에도 주가가 하락하지 않는 현상은 결코 합리적이지 못하다. 즉, 부인공시는 조회공시 후에 번복되는 경우가 없어 정확하지만 시장이 이를 자본화(Capitalize)하지 않아 정보로서의 효용성이 없다. 그런데, 조회공시 유형별로 정보전달 효과는 조금씩 차이가 있어 일반 투자자들에게 투자 전략적으로 시사하는 바가 있다. 확인공시의 경우는 주가의 상승정도는 다른 조회공시에 비하여 약하지만 공시 당일 유의한 양의 초과수익률(t=0때 2.12%)을 기록하여 확인공시의 효과가 있다 할 수 있다. 또한 검토 중 공시나 부인 공시의 경우, 확연하게 조회의 내용이 즉각적으로 시장에 전달이 되지는 못하지만, 소문이나 풍문의 진위가 추후에 지연되면서 시장에 반영이 되는 듯하여(특히 무상 증자설 부인의 경우) 제한적이지만 정보의 효용성을 볼 수 있었다. 한편 검토 중 공시의 초과수익률이 확인공시나 부인공시의 경우보다 월등히 높게 나타나 증권시장에 퍼져있는 막연한 풍문이 오히려 투자자들의 초과수익을 더 높일 수 있다는 증권가의 주장을 뒷받침한다. 결론적으로 조회공시 유형별로 정보전달 효과를 살펴보았을 때 증자에 대한 풍문은 그 진위여부나 실시시기에 관계없이 사후적으로 투자자의 수익률에 음(-)의 방향으로 작용하지 않는다는 것이다.

• Journal of Navigation and Port Research
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• v.41 no.1
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• pp.17-24
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• 2017

This study uses Conjoint Analysis to study optimal port operations at the newly built International P assenger Terminal (IPT) at Inchon Port, Korea. The perceptions of users, operators, and the Incheon Port Authority are compared and analyzed. The results of user Conjoint Analysis showed that rent calculation method was the most important factor in the NIPT operation plan, followed by establishing automation and the size of the site area. For the Incheon Port Authority and operators, the rent calculation method turned out to be the most important factor for NIPT operation plans. It was followed by establishing automation and the site area. Utility results showed the "investment cost preservation method" to have the highest rent calculation utility, "yard automation" as the priority, and "43,000 pyeong-48,000 pyeong" as the optimal site area.

• Fire Science and Engineering
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• v.24 no.1
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• pp.31-39
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• 2010

Although the subject of sprinkler installations in Korean regulations is less strict than in other advanced countries, many building owners and managers tend to install sprinklers only in the types of buildings designated by law or create building designs for which sprinkler installation standards are not applied. This is because priority is given to cutting installation expenses rather than providing building fire safety. In this study, the benefit is estimated for various expenses from installation and maintenance of sprinklers as an investment. As a result of comparing sprinkler system installation expense and the financial benefit by efficiency analysis, the payback period is 1/20 of the building life expectancy and its efficiency is twice the expense. Therefore, installation of sprinklers by regulation has financial efficiency and it is desirable to broadly encourage the installation of sprinklers.

• Proceedings of the Korean Statistical Society Conference
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• 2002.11a
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• pp.169-174
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• 2002

본 연구는 k개 지수분포 모수들의 기하평균에 대한 베이지안추정 방법을 제시하였다. 이를 위해 Tibshirani가 제안한 직교변환법으로 비정보적 사전확률분포를 도출하여 모수들의 결합사후확률분포를 유도해 내었으며, 이 분포 하에서 가중 몬테칼로 방법을 사용하여 기하평균을 추정하는 절차를 제안하였다. 모의실험과 실제자료의 예를 통해 제안된 베이지안 추정의 유효성 및 효용성을 보였으며, 본 연구에서 제안한 사전확률분포가 전통적인 포함확률을 기준으로 볼 때, Jeffrey의 사전확률분포 보다 더 유효한 추정을 함을 보였다.

• Proceedings of the Korean Society for Information Management Conference
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• 2006.08a
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• pp.145-152
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• 2006

저자동시인용분석 기법은 인용을 통해서 특정 주제분야의 지적 구조를 파악하는 수단으로 널리 사용되고 있다. 그러나 저명한 연구자 위주의 분석이 되기 쉬우므로 은퇴자나 고인을 비롯한 비현역 연구자가 포함되는 경우도 흔하다. 또한 비영어권 국가의 국내 연구동향을 분석할 경우에는 분석결과에 국내 연구자가 상당수 배제되는 상황도 발생한다. 이 연구에서는 국내 현역 연구자 위주로 최근 동향을 분석할 수 있는 새로운 지적 구조 분석법인 서지적 저자결합분석을 제안하고 실제 자료를 대상으로 분석하여 효용성을 검증하였다