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        검색결과 45

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Recently, the single-step genomic best linear unbiased prediction (ssGBLUP) method, which incorporates not only genomic information but also phenotypic information of pedigree, is under study. In this study, we performed a ssGBLUP analysis on a commercial Hanwoo population using phenotypic, genotypic, and pedigree data. Methods: The test population comprised Hanwoo 1,740 heads raised in four regions of Korea, while the reference population used Hanwoo 18,499 heads raised across the country and two-generation pedigree data. Analysis was performed using genotype data generated by the Hanwoo 50 K SNP beadchip. Results: The mean Genome estimated breeding values (GEBVs) estimated using the ssGBLUP methods for carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS) were 7.348, 1.515, -0.355, and 0.040, respectively, while the accuracy of each trait was 0.749, 0.733, 0.769, and 0.768, respectively. When the correlation analysis between the GEBVs as a result of this study and the actual slaughter performance was confirmed, CWT, EMA, BFT, and MS were reported to be 0.519, 0.435, 0.444, and 0.543, respectively. Conclusions: Our results suggest that the ssGBLUP method enables a more accurate evaluation because it conducts a genetic evaluation of an individual using not only genotype information but also phenotypic information of the pedigree. Individual evaluation using the ssGBLUP method is considered effective for enhancing the genetic ability of farms and enabling accurate and rapid improvements. It is considered that if more pedigree information of reference population is collected for analysis, genetic ability can be evaluated more accurately.
        4,000원
        2.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the environmental impacts of fossil fuel energy sources increase, the South Korean government has tried to change non-environmental- friendly enery sources to environmental-friendly energy sources in order to mitigate environmental effects, which lead to global warming and air pollution. With both a limited budget and limited time, it is essential to accurately evaluate the economic and environmental effects of renewable energy projects for the efficient and effective operation of renewable energy plants. Although the traditional economic evaluation methods are not ideal for evaluating the economic impacts of renewable energy projects, they can still be used for this purpose. Renewable energy projects involve many risks due to various uncertainties. For this reason, this study utilizes a real option method, the Geske compound model, to evaluate the renewable energy projects on Jeju Island in terms of economic and environmental values. This study has developed an economic evaluation model based on the Geske compound model to investigate the influences of flexibility and uncertainty factors on the evaluation process. This study further conducts a sensitivity analysis to examine how two uncertainty factors (namely, investment cost and wind energy production) influence the economic and environmental value of renewable energy projects.
        4,200원
        3.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In general, a high-performance concrete construction method is a method of loading mixed cement and other materials on a mobile mixer equipped with a concrete plant. However, the construction cost is high because the unit cost of the mixed cement is very high and the equipment usage fee of the mobile mixer is also high. To compensate for these drawbacks, a cellular spray concrete method was developed. This is a highly functional customized concrete construction method in which admixtures are added to high-flow concrete with cellular (air bubbles) added at the site and constructed through spraying. METHODS : Field workability evaluation using cellular concrete was carried out using a spray method in 2017 and an anti-foaming agent in 2018. The test construction section was set as a new road-pavement construction site. After construction, strength, durability characteristics, and void analysis were performed to compare the construction methods. The results of laboratory tests under optimal conditions were also compared to the on-field results. By comparing the indoor mixing and the on-field results, we analyzed whether there were any problems concerning the performance expression. The economic feasibility at the initial construction stage was analyzed by comparing the existing and the cellular concrete construction methods in terms of material cost and equipment usage fee. RESULTS : In the case of cellular spray concrete, construction through spraying is cumbersome, and the need to additionally use large equipment such as a pump car and compressor constitutes a disadvantage. However, the most relevant feature is that it can be constructed not only on the floor, but also on a slope. In the case of cellular concrete with an antifoaming agent, it was possible to quickly produce high-performance concrete using on-site remixing equipment. By supplying materials to the pouring surface using a conveyor, smooth construction and construction in narrow spaces were also possible. CONCLUSIONS : The cellular concrete method allows the immediate on-site production of high-performance concrete, and it is possible to selectively apply spray construction, antifoaming agent construction, etc.
        4,000원
        5.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 세장한 구조의 장경간 아치교의 시공 및 설계가 증가하고 있는 추세로서 아치부재에 적용되는 강재를 경량화시킬 수 있는 콘크리트 충전강관 부재에 대한 수요가 증가하고 있다. 이는 장경간 아치교량의 구조적 특성상 압축력 지지에 유리한 콘크리트를 강재와 같이 이용함으로써 구조적 효율성을 증대시킬 수 있다. 본 연구에서는 콘크리트 충전강관을 사용한 아치교 설계에 적용되는 초기변수를 고려하여 하로아치교를 대상으로 강관 단면 내 콘크리트 충전길이, 트러스타입의 아치리브 높이, 강관 단면의 재료강성 변화 등의 영향을 유한요소해석을 통해 비교분석하였다. 이를 토대로 콘크리트 충전강관의 아치교 최적화 설계 방법을 제안하고 콘크리트 충전강관의 아치교 적용성을 확보할 수 있도록 경제성 분석을 수행하였다. 분석결과 콘크리트 충전강관 아치리브단면 적용 시 기존 아치리브에 비해 하로아치교의 경우 22.0%의 강재절감이 가능하며 콘크리트 충전에 따른 비용증가는 발생하나 전체 공사비의 경우 18% 절감되어 경제적으로 효과를 보였다.
        4,000원
        7.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There are two methods for evaluating two or more mutually exclusive projects. One is a total investment approach and the other is an incremental investment approach. The former can rank projects by the criterion of the net present value, but the latter can’t do it. An incremental investment approach is only possible when all pairwise alternatives are compared. Thus an incremental investment approach is superior in ranking them over an incremental investment approach. To do so, a principle of comparison must be established. Comparisons of profitability are reasonable when operating the same amount of investment over the same period of time. One principle is that all projects are invested in the largest of the projects. Another principle is that all projects are invested during the longest project life of the projects. In this paper, even if the principle is followed, it will be shown that the external rate of return fails to rank them. However, the productive rate of return criterion would prove to be able to rank them like the net present value standard, provided that the principle of comparison is kept. In addition, rate of returns can be assessed so that all mutually exclusive projects can be compared at once, such as on the criterion of the net present value. That is, it can be also compared with many other returns, such as the profit rates on financial investments or real investments.
        4,000원
        8.
        2018.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Less mature nuclear reactor technologies are characterized by a greater uncertainty due to insufficient detailed design information, operational data, cost information, etc., but the expected performance characteristics of less mature options are usually more attractive in comparison with more mature ones. The greater uncertainty is, the higher economic risks associated with the project realization will be. Within a comparative evaluation of less and more mature nuclear reactor technologies, it is necessary to apply economic risk measures to balance judgments regarding the economic performance of less and more mature options. Assessments of any risk metrics involve calculating different characteristics of probability distributions of associated economic performance indicators and applying the Monte-Carlo method. This paper considers the applicability of statistical risk measures for different economic performance indicators within a trial case study on a comparative evaluation of less and more mature unspecified LWRs. The presented case study demonstrates the main trends associated with the incorporation of economic risk metrics into a comparative evaluation of less and more mature nuclear reactor technologies.
        4,000원
        10.
        2018.04 구독 인증기관·개인회원 무료
        For economic effect on an import prohibition for the buff-tailed bumblebee, income of the bumblebee products, function, economic effect of pollinating insects and bumblebee were analyzed. The largest incremental gain was observed when using domestic bumblebees. Incremental revenue showed a larger incremental revenue in pollination than artificial pollination, the cost of artificial pollination was lowest for incremental cost, followed by domestic bumblebees, honeybees and imported bumblebees. Consequently, higher economic value can be achieved when domestic bumblebees and honeybees are used. According to this study, as it is used to make policy decisions on the prohibition of import of buff-tailed bumblebee, other alternative plan can be utilized due to its import prohibition.
        11.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Ministry of Agriculture, Forestry, Livestock and Food in Korea has done an R&D project to develop new corn and soybean varieties and cultivation technologies with Seoul National University and on-site company for three years in Russia, where Korean government has done the overseas’ agriculture for more than a decade. The objective of this study is to analyze the investment value of three years’ funding. For this, a Cost-Benefit and Scenario analysis approaches were used. The results revealed that 1) For the case of soybean, cost seems to outweigh benefits under a pessimistic scenario, but otherwise in case of neutral and optimistic scenarios. 2) The result of corn shows high economic efficiency for all scenarios. 3) The most important implication of this study is that Korea’s oversea agriculture R&D projects need to expand to different countries, regions, and crops.
        4,000원
        12.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For economic evaluation of integrated operation to sewage facilities, benefit-cost analysis was performed to watershed sewage works project in 7 watershed areas, 156 facilities. In this study, the cost before and after integrated operation was compared and benefits are calculated from the reduction of operators, increasement treated pollution loads, reduction cost through operation convenience, reduction water consumption through effluent reuse, and improvement of life benefit. The result showed that cost was 8,500million won and benefit was 16,747million won, so benefit was 49% higher than cost. B/C analysis result showed that B/C ratio was 1.97 and it is similar to other researches. The benefits of integrated operation included convenience of data management, increase of emergency response, decrease of complains with sewage which was not reflected numerically, so the benefits of integrated operation were expected much greater than this result.
        4,000원
        13.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        허베이 스피리트호의 유류유출량이 씨프린스호의 것에 비해 2.5배에 불과하지만, 그 경제적·환경적·사회적 피해는 30배에 이를 정도로 대규모 유류유출의 피해는 기하급수적으로 증가할 수 있다. 본 연구에서는 이와 같은 재난적 해양환경오염사고에 신속하고도 효율적으로 대응할 수 있는 다목적 대형방제선의 건조에 대한 기술적·경제적 타당성을 분석함으로써 다목적 대형방제선의 건조에 대한 당위성과 정당성을 확보하고자 한다. 다목적 대형방제선의 기술적 타당성분석과 선진해양국의 많은 사례를 검토한 결과, 4,000톤급의 자항식 호퍼준설선 겸용 방제선을 건조하는 것이 적합한 것으로 판단되었다. 경제적 타당성 분석결과, 가장 보수적인 추정의 B/C ratio는 0.82로 경제성에 미달하지만 자구적 노력을 통하여 경제성을 확보할 수 있다. 한편, 중간추정치와 낙관적 추정치의 B/C ratio는 각각 2.72와 5.82로 이 사업의 경제적 타당성을 충분히 확보할 수 있다.
        4,000원
        14.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구에서는 물량저감 철근상세를 갖는 중공 철근콘크리트 교각 시스템의 전용 설계프로그램과 소성설계 적용 결과를 제시하였다. 개발된 물량저감 철근상세는 경제성과 합리성을 갖으며 공사기간의 단축을 가져올 수 있다. 물량저감 중공 철근콘크리트 교각의 적용을 통해 경제성 평가를 수행하였다. 평가 결과 개발상세가 기존상세에 비해 구조적 합리성, 시공성, 그리고 경제성 등이 우수함을 확인하였다.
        4,000원
        15.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study evaluates the economic value of national highway construction projects using Real Option Pricing Models. METHODS : We identified the option premium for uncertainties associated with flexibilities according to the future's change in national highway construction projects. In order to evaluate value of future's underlying asset, we calculated the volatility of the unit price per year for benefit estimation such as VOTS, VOCS, VICS, VOPCS and VONCS that the “Transportation Facility Investment Evaluation Guidelines” presented. RESULTS: We evaluated the option premium of underlying asset through a case study of the actual national highway construction projects using ROPM. And in order to predict the changes in the option value of the future's underlying asset, we evaluated the changes of option premium for future's uncertainties by the defer of the start of construction work, the contract of project scale, and the abandon of project during pre-land compensation stages that were occurred frequently in the highway construction projects. Finally we analyzed the sensitivity of the underlying asset using volatility, risk free rate and expiration date of option. CONCLUSIONS: We concluded that a highway construction project has economic value even though static NPV had a negative(-) value because of the sum of the existing static NPV and the option premium for the future's uncertainties associated with flexibilities.
        4,800원
        16.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to evaluate the economic validity of artificial reefs facilities and seeds release programs in Jeju Trial Sea Farm Project for raising fishing people’s revenue. The results of this study show the artificial reefs facilities and seeds release programs have net present value of 15,962.63 million won, internal rate of retrurn 13.86%, and benefit-cost of 1.912 under a 5.5% social discount rate. This suggests that in Jeju trial sea farm project, artificial reefs facilities and seeds release programs increase fisherperson’s revenue.
        5,200원
        17.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 시험은 육성기 흑염소에 있어서 조사료원이 볏짚 위 주일 때, 농후사료 급여 수준이 발육, 사료이용성 및 경제 성에 미치는 영향을 구명하기 위해 실시하였다. 육성기 암 컷 흑염소 40두를 공시하여 농후사료 급여수준을 체중의 1.5% (T1), 1.8% (T2), 2.1% (T3) 및 자유채식구(T4)로 나누 어 급여 하였고 조사료원은 볏짚을 자유채식 하도록 하였 다. 그 결과, 일당 증체량은 T1 (1.5%), T2 (1.8%), T3 (2.1%) 및 T4(자유채식)구가 각각 50.23, 60.37, 71.46 및 98.90 g으로 농후사료의 급여 수준이 높아질수록 유의하게 높았으며(p<0.05), 조사료인 볏짚의 사료 섭취량은 농후사 료 급여수준이 증가 할수록 유의적으로 감소하는 결과를 보였다(p<0.05). 경제성 분석에 있어서 육성기 흑염소 경영 비는 농후사료를 1.5%, 1.8%, 2.1% 및 자유 채식하였을 때 각각 46,704원, 49,998원, 54,701원 및 74,613원으로 농후사 료의 급여수준이 증가할수록 경영비는 증가하였다. 이는 증체량에 있어서 T4(자유채식)구가 가장 많이 증가하였지 만 T3 (2.1%)구보다 사료비에 있어서 두당 19,912원 더 많 이 들었다. 이상의 시험 결과를 종합하여 고려할 때, 육성 기 흑염소에 있어서 조사료 원이 볏짚 단용일 경우에는 농 후사료를 2.1% 수준으로 급여하는 것이 가장 바람직할 것 으로 사료 된다.
        4,000원
        18.
        2013.10 구독 인증기관 무료, 개인회원 유료
        Virtual metrology(VM) is a promising technology which can convert off-line sampling inspection into on-line total inspection at the manufacturing process. This paper provides an economic evaluation model of VM system which predicts the defects of a target process with Bernoulli sampling inspection. For this purpose, we build M/G/1 queueing models of two systems. One is VM non-applied system and the other is VM applied one. We derive total costs per unit time of each system and conduct sensitivity analysis according to variations of input parameters such as defect rates, various process costs and VM prediction error rates. The proposed analysis model is expected to be used for evaluating economic values of VM system implementation projects.
        4,000원
        19.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        현재 국내에서 생산되는 구조용 강재의 강도는 크게 5가지로 구분할 수 있다. 경제적인 구조설계를 하기 위하여 적절한 강도의 선정이 우선적으로 요구되는데 현재는 이와 관련된 기존 자료가 충분치 않은 상태이다. 최근, 국내에서 항복강도가 650MPa인 고강도 강재가 개발되어 구조용 강재의 강도 범위가 더 커졌기 때문에 부재 종류별 강재의 선택에 따른 경제성의 차이도 더 커졌을 것으로 예상된다. 본 논문에서는 경제적인 구조설계에 도움이 되도록, 항복강도 235MPa, 325MPa 및 650MPa 강재를 다양한 구조부재에 적용함으로서, 고강도 강재 적용에 따른 부재 종류별 경제성을 분석하였다.
        4,000원
        20.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 흑염소 비육에 있어서 조사료원이 볏짚 단용인 경우 농후사료 급여수준이 흑염소의 사료섭취량, 체중변화, 도체특성 및 경제성에 미치는 영향을 구명하기 위하여 실시하였다. 비육 흑염소 40두를 공시하여 농후사료 급여수준을 체중의 1.5% (T1), 2.0% (T2, 농가관행), 2.5% (T3) 및 자유채식구(T4)로 나누어 급여 하였고 조사료는 볏짚을 자유채식 시켰으며그 결과는 다음과 같다. 볏짚인 조사료 섭취량은 농후사료 급여수준이 증가 할수록 감소하였으며, 흑염소의 일당증체량은 체중대비 농후사료 급여수준 1.5, 2.0, 2.5% 및 자유채식구가각각 22, 50, 69 및 94 g으로 농후사료 급여수준이 증가할수록 유의적으로 증가하였다(p <0.05). 비육 흑염소의 도체율은 농후사료 급여수준을 체중비 1.5, 2.0, 2.5% 및 자유채식 시켰을 때 각각 41.77, 42.78, 46.12 및 49.78%로농후사료 급여 수준이 증가할수록 증가하였으며(p<0.05), 지방률도 농후사료 급여수준이 증가 할수록 유의적으로 증가하였다. 경제성 분석에서는 농후사료 급여수준이 증가할수록 소득은 증가하였으며, 자유채식구가 두당 34,270원으로 가장 소득이 높았다. 이상의 결과를 종합적으로 고려할 때 조사료 자원이 볏짚 단용일 경우 비육 흑염소의 농후사료 급여 수준은자유채식 시키는 것이 사료이용성, 발육, 도체율 및 경제성에서 가장 유리할 것으로 사료되며, 흑염소의 비육을 위한 조사료 자원으로서볏짚 단용은 농후사료비의 가중을 가져오므로앞으로는 흑염소 비육을 위한 새로운 조사료자원의 개발이 필요하다고 하겠다.
        4,000원
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