• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.272-277
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• 2012

KORAIL's logistics business coefficient is improved slightly from 197.4 in 2009 to 190.7 in 2010 but the cost is still high compared to the revenues. In order to derive activities for the efficient logistics and measure their effects quantitatively, the analysis of various indexes that can be extracted from the statistical data is very important. In this study, the various indexes are analyzed to evaluate the efficiency of freight cars based on railway logistics. It can be used to estimate the various activities for the efficient logistics associated with freight cars. We suggest the Indexes as the number of transport, cumulative transport distance and transport income to evaluate the efficiency of freight cars and they should be applied according to the characteristics of each index.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.526-527
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• 2008

태양광발전은 성장전망으로 다양한 이점을 보유하고 있으며 그 중에서 화력, 원자력 등 기존 에너지원과 달리 온실가스 배출, 소음, 환경파괴 등의 위험성을 초래하지 않는 무공해 에너지란 점과 또한 태양광은 석유, 천연가스처럼 수입에 의존할 필요 없이 자체 조달이 가능해 에너지 안보 측면에서도 매우 유리하며 막대한 부존 량의 바탕으로 적용영역의 확대와 기술혁신을 통해 효율성 제고의 가능성이 매우 크다는 평가이다. 유지비용도 저렴하여 향후 기술혁신에 따른 원가절감 및 효용성 제고의 가능성도 풍부하므로 앞으로 크게 성장하기에 본 논문에서는 계통연계 태양광발전 시스템의 모델링을 제시 계통과의 연계 시 전압변동에 대한 시뮬레이션을 수행하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.501-504
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• 2000

원격 병리 진단 시스템은 웹을 기반으로 하여 중소병원과 종합병원을 연결하고, 이들 사이에서 발생하는 병리검사의 효율성을 향상시킬 목적으로 개발되었다. 원격병리진단 시스템은 크게 검체영상 처리 모듈, 현미경 원격제어 모듈, 병리정보 처리 모듈로 구성되며, 각각을 컴포넌트화 하여 재사용성 및 확장성을 극대화하였다. 현재미국 등과 같은 서구에서 이와 유사한 시스템이 이미 개발되어 상용화되고 있지만, 국내에서는 아직까지 막대한 초기비용의 부담으로 인하여 도입이 늦어지고 있는 실정으로, 이에 원격 병리 진단 시스템은 보다 낮은 비용으로 본 시스템에 있어서 적용 가능한 모든 분야에 활용하고자 한다. 이를 통하여 외국으로부터의 시스템 수입대체 효과를 볼 수 있을 뿐만 아니라, 세계 각국으로의 수출에 따른 외화획득에도 크게 기여할 것이다.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.205-214
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• 2019

In Korea, the first-price sealed bid auction and the constrained mean-price sealed bid auction(buchal-je in Korean) have been used alternatively as procurement auctions. In this paper, we characterize the constrained mean-price sealed bid auction in the context of mechanism design. We consider the general ?-bidder case in which each bidder has private information. Under the assumptions of uniformly distributed valuations and linear strategies, we derive the equilibrium of the constrained mean-price sealed bid auction. Furthermore, we analyze the efficiency and the expected revenue of this auction mechanism in comparison with the first-price sealed bid auction. Finally, we conclude with the critical remarks on the practical intention of the government which uses this auction.

• Journal of Korean Society of Transportation
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• v.24 no.6 s.92
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• pp.45-54
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• 2006

The Purpose of this Paper is to compare and analyze the operational condition of corporation-owned and owner-driver taxies using tachometer output data. The empirical findings from this study are as follows : First, although corporation-owned taxies have long operating mileage and service driving mileage per vehicle. the service rate of owner-driver taxies were 3.5 percent higher than corporation-owned taxies. Secondly it is found that operation mileage, service driving mileage, and service Income except non-service driving mileage have statistically significant differences between corporation owned and owner-driver taxies. In addition. there was a weak correlation between the income and non-service driving mileage of owner-driver taxies. It is concluded that owner-driver taxies joined the call-taxi association and call-taxi services decreased non-service driving mileage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.318-332
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• 2015

The maize production in South-eastern Asian countries showed a continuous increase with increasing poultry-livestock from the beginning of the 1990s to early 2010. Also the need for a new variety development of each contries was increased rapidly in the same period. Single-Cross hybrid varieties have been developed and supplied from 2001 instead of multi-cross maize varieties since 1992 in Indonesia. In Cambodia, CP group is mainly manufacturing feeds with most of the forage maize from farmers who are growing its seeds from the company. Cambodian main cultivars are varieties of multinational corporations such as DK8868 from Monsanto, NK6326, NK7328 from Syngenta and CP333 from CP group including local business company. Vietnam is the main maze importing country in South-Eastern Asia which had imported 13 times scale of amount compared to exports in average from 1990 to 2011. Vietnamese government has developed a range of varieties for improving their efficiency in production, such as the LVN-10 with political investments. Their production has been reached to 80% of the total. According to the 2012 MIFAFF (Ministry for Food, Agriculture, Forestry and Fisheries) data in Korea, domestic edible maize cultivation area was approximately 15,000ha. It showed 74,399 tons of production, 3.8% of food self-sufficiency in maize and around 0.9% of grain self-sufficiency rate. The consumption of grain is mostly rely on imports in Korea. To overcome the limit of the domestic seed market and increase maize self-sufficiency, the need to develop maze varieties for world-class is increasing at present through analyzing the market trend and prospect of the seed industry in South-eastern Asia.

• Environmental and Resource Economics Review
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• v.6 no.2
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• pp.171-191
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• 1997

83년 7월부터 NYMEX 선물시장에서 거래되기 시작한 원유선물은 90년대 들어 주식 채권 외환 등의 금융시장과 관련하여 크게 성장하고 있으며, 원유선물가격이 현물시장에서의 가격형성에 큰 영향을 미치고 있다. 따라서, 원유선물가격이 미래의 현물가격에 대한 최적의 예측치라고 하는 합리적기대모형(合理的期待模型)에 의거하여 원유선물 가격과 현물가격의 변화추이 및 그들 사이의 장(長) 단기(短期) 균형관계(均衡關係)(동태적통합(動態的統合))와 효율성(效率性)등을 일별(日別) NYMEX 선물유가(근월도래선물(近月到來先物)의 종가(終價))와 WTI 현물유가의 자료를 이용하여 계량분석하였다. 원유선물가격과 현물가격은 단위근(單位根)을 갖는 불안정(不安定)한 시계열이지만, 선물유가와 현물유가사이에는 공적분관계(共積分關係)(공통확률적추세(共通確率的趨勢))가 있어 장기적(長期的) 균형관계(均衡關係)가 존재하며, 또한 공시계열상관관계(共時系列相關關係)(공통안정적순환(共通安定的循環))가 있어 단기적(短期的) 균형관계(均衡關係)도 존재하는 것으로 보여진다. 그리고 선물유가는 미래의 현물유가에 대한 예측력이 있는 것으로 보여진다. 따라서, 원유선물가격이 미래의 현물가격에 대한 최적의 예측치라고 히는 합리적기대모형(合理的期待模型)과 일치하는 것으로 나타났다. 원유선물가격이 현물가격과 장(長) 단기적(短期的)으로 동태적(動態的)인 균형관계를 보이고 있으므로 정부의 합리적인 수입선다변화정책과 유가자유화에 따른 석유업계의 효율적인 운영방안의 하나로 원유선물시장의 활용이 더욱 더 필요할 것으로 생각된다.

• Journal of dental hygiene science
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• v.2 no.2
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• pp.63-67
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• 2002

The purpose of this study was to develop more effective dental health education program and to reduce the occurrence of dental diseases among industrial men-workers in Korea. The questionaire and dental examination were given to 782 industrial men-workers who visited Asan Medical Center for the purpose of health examinations in 2000. The obtained results were as follows; 1. According to the results of logistic regression analysis, both ages (especially under 30's: P=0.027) and monthly incomes (especially under 1,000,000 won: P=0.000) show negative relationships with the occurrence of dental caries. 2. As the results of logistic regression analysis, ages shows positive relationship and monthly incomes shows negative relationship (only under 1,000,000 won: P=0.059) with the occurrence of missing teeth. 3. According to the results of logistic regression analysis of periodontal disease, the model shows no significance (P=0.117). 4. As the results of logistic regression analysis, both monthly incomes and ages show positive relationships with the occurrence of abrasion.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.179-186
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• 2017

For more efficient and proactive safety control of imported food, new trend in U.S. is emerging, which assesses the food safety control systems of exporting countries using Systems Recognition Assessment Tool and helps ensure safety of imported foods. This study examines trends in development and application of assessmemnt tool and country assessment reports in U.S. where an active discussion on this issue is in progress. The expert interviews were also conducted. U.S. Systems Recognition Assessment Tool was developed by FDA to recognize the potential value in leveraging the expertise of foreign food safety systems and help ensure safety of imported food. The tool is comprised of ten standards and provides an objective framework for determining the robustness of trading partners' overall food safety systems. Using its own tool, the U.S. FDA conducted a preliminary assessment of the food safety control systems of New Zealand and Canada. According to the U.S.-New Zealand and the U.S.-Canada assessment reports, the overall structure of the systems was similar between the countries. In summarizing the opinions of experts, such a trend in National Food Safety Control System Assessment may be utilized in the sanitary assessment and the control of imported food border inspection frequency before importing food. It would contribute to more effective distribution of national budget and increased public trust. Additionally, international collaboration as well as securing of qualified experts and sufficient budget appear to be crucial to further increase the utility of National Food Safety Control Systems Assessment. In conclusion, firstly, it is critically important for the competent authority of South Korea to proactively respond to international trend in National Food Safety Control System Assessment by identifying the details of its background, assessment purpose, core assessment elements, and assessment procedures. Secondly, it is necessary to identify and complement the weaknesses of Korea's food safety control system by reviewing it with U.S. Systems Recognition Assessment Tool. Thirdly, by adapting the assessment results from imported countries' food safety control systems to the imported food inspection intensity, the resources previously used in inspecting the imported food from accredited countries can be redistributed to inspecting the imported food from unaccredited countries, and it would contribute to more efficient imported food safety control. Fourthly, the competent authority of South Korea should also consider developing its own assessment tool designed to reflect the unique characteristics of its food safety control system and international guidelines.

• Journal of Intelligence and Information Systems
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• v.28 no.3
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• pp.139-159
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• 2022

As interest in health functional foods has increased since COVID-19, the importance of imported food safety inspections is growing. However, in contrast to the annual increase in imports of health functional foods, the budget and manpower required for inspections for import and export are reaching their limit. Hence, the purpose of this study is to propose a machine learning model that efficiently detects unsuitable food suitable for the characteristics of data possessed by government offices on imported food. First, the components of food import/export inspections data that affect the judgment of nonconformity were examined and derived variables were newly created. Second, in order to select features for the machine learning, class imbalance and nonlinearity were considered when performing exploratory analysis on imported food-related data. Third, we try to compare the performance and interpretability of each model by applying various machine learning techniques. In particular, the ensemble model was the best, and it was confirmed that the derived variables and models proposed in this study can be helpful to the system used in import/export inspections.