• 농촌계획
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• 제25권4호
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• pp.27-33
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• 2019

Agricultural water for crops are faced with the need to improve the use efficiency due to the impact of climate change. Water productivity (WP) is known as a good indicator for assessing resources efficiency. This study was conducted to assess WP of rice and potential water consumption (PWC) as new indicator for water use efficiency assessment. The average of WP was 0.7 kg/㎥, and Jeonbuk had the highest WP as 0.83 kg/㎥. Kangwon and Kyungbuk had the lowest WP as 0.59 kg/㎥. PWC showed the same trend because of rice consumption per capita, but Total PWC considering population living in each province showed the different trend with PWC. Every year, the changing patterns of WP was increasing little by little, and the patterns of PWC was decreasing greatly than WP. These results mean that WP has been slowly improved through breed development and irrigation techniques, and PWC was affected by reduced rice consumption and WP increasing. PWC could also be useful as an indicator to compare the water use efficiency between provinces or nations.

• 한국지반환경공학회 논문집
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• 제12권2호
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• pp.63-68
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• 2011

본 연구의 목표는 전자빔 공정을 적용하여 1,4-dioxane의 제거효율 및 독성평가를 하는 것이다. 이 실험에서는 전자빔 선량과 1,4-dioxane의 초기 농도에 따른 저감 효율 및 scavenger gas에 따른 무기화의 정도를 알아보았다. 또한 녹조류 중 하나인 Pseudokirohneriella Subcapitata를 이용하여 생물독성과 위해성 평가를 통한 독성저감기술을 확립하였다. 그 결과 1,4-dioxane은 전자빔 조사량이 증가할수록 분해 효율이 향상되었고, Radical Scavenger gas에 의한 TOC 제거는 $N_2O$나 $O_2$를 용해시켰을 때 효율이 증가되었다. 4일(96hrs) 후 독성평가 결과 전자빔 조사 강도의 증가에 따라 독성 영향이 저감되는 것을 알 수 있었다.

• 한국농공학회지
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• 제45권1호
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• pp.23-32
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• 2003

The objective of this study is assessing water management efficiency using water withdrawals from rivers and water requirements for paddies. The water management efficiency was defined by the ratio of water requirements and water withdrawals. Water withdrawals were estimated using the operating times and pumping capacity of the pumping stations from 1992 to 1999 in the Han River and Nakdong River basins. Water requirements were estimated by adding the evapotranspiration of the crops and infiltrations in the irrigated area. Evapotranspiration from the paddies was calculated by the FAO modified Penman method with observed daily weather data. The monthly water management efficiency was analyzed for each pumping stations and the district offices of KARICO (Korea Agricultural and Rural Infrastructure Corporation). The efficiencies of 59 pumping stations in the Han River basin varied from 19% to 135%, and the average was 61%. The efficiencies of 146 pumping stations in the Nakdong River basin ranged from 17% to 190%, and the average was 72%. There were no good correlations between the water management efficiency and pump capacity or irrigated area, it showed that the water management efficiency was affected by the traditional water management practices rather than the scale of irrigation district.

• Steel and Composite Structures
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• 제44권1호
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• pp.105-117
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• 2022

Impact resistance efficiency of the newly designed sandwich beam with a laterally arched core as bio-inspired by the woodpecker is numerically investigated. The principal components of the beam comprise a dual-core system sandwiched by the top and bottom laminated CFRP skins. Different materials, including hot melt adhesive, high-density polyethylene (HDPE), acrylonitrile butadiene styrene (ABS), epoxy resin (EPON862), aluminum (Al6061), and mild carbon steel (AISI1018), are considered for the side-arched core layer of the beam for impact efficiency assessment. The aluminum honeycomb takes the role of the second core. Contact force, stress, damage formation, and impact energy for beams equipped with different materials are examined. A diversity in performance superiority is noticed in each of these indicators for different core materials. Therefore, for overall performance appraisal, the impact resistance efficiency index, which covers several chief impact performance parameters, of each sandwich beam is computed and compared. The impact resistance efficiency index of the structure equipped with the AISI1018 core is found to be the highest, about 3-10 times greater than other specimens, thus demonstrating its efficacy as the optimal material for the bio-inspired dual-core sandwich beam system.

• The Journal of Asian Finance, Economics and Business
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• 제9권7호
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• pp.261-271
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• 2022

Over the last 20 years, the insurance industry in Vietnam has been rapidly growing with an average annual growth rate of 21%, one of the most active markets in Southeast Asia, raising the question of efficiency to managers, investors, and regulators. This article is one of the first research works using Data Envelopment Analysis combined with the Malmquist index over the period from 2016 to 2020 for 37 insurance firms in Vietnam to investigate the efficiency of this sector. The value-added approach is employed with total equity and operating expenses as inputs, finance income, and gross written premium as outputs. The findings reveal that most of Vietnam's insurance companies are operating quite effectively, and the non-life sector is more efficient than the life sector. There is also a regression in efficiency change, while there is a progression in technological change and total factor productivity change during the period examined. The goal of this research is to give a fundamental understanding of the overall efficiency of insurance firms in Vietnam, and help managers, investors, policyholders, and government agencies make better decisions regarding self-assessment, M&A activities, deregulation... Consequently, the insurance sector could improve in terms of efficiency and develop sustainably over time.

• 한국환경농학회지
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• 제27권3호
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• pp.267-273
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• 2008

안전농산물에 대한 국민의 관심 증대와 농업환경자원의 유지 보전을 위한 지속적인 농업생산 방안으로 친환경농업 육성의 필요성이 증대되어 왔다. 이에 우리나라에서는 친환경 농업이 빠르게 성장하여 1999년 1300호였던 인증농가가 2007년에는 100배 증가하여 13만호에 이르고 있다. 그러나 친환경농업의 빠른 증가 추세에도 불구하고 친환경농업이 농업생태계에 미치는 영향에 대한 정량적인 연구는 미흡한 실정으로 친환경농업의 올바른 확산을 위해서는 농업생태계에 미치는 영향을 규명하고, 지속가능성을 정량화하는 연구가 필요하다. 이에 친환경농업의 지속가능성을 평가하고자 2006년부터 2007년까지 완주군 고산면 광역친환경농업단지 벼유기농업단지에서 쌀생산 시 에너지효율 및 양분수지를 조사하였다. 그 결과 벼유기농업단지가 관행논보다 에너지효율은 낮았으나 재생가능한 에너지 자원을 사용하는 유기농법이 화학비료나 농약을 사용하는 관행농법에 비하여 자원이용의 지속가능도는 높았다. 또한 벼유기농업단지는 과량의 축분퇴비 시용으로 토양 내 인산과 칼륨이 과다 축적되어 있으므로 축분 퇴비의 시용량을 줄이고 질소대비 인산과 칼륨의 함량이 비교적 낮은 자운영 등을 이용한 시비개선이 필요할 것으로 판단된다.

• Communications for Statistical Applications and Methods
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• 제7권2호
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• pp.427-433
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• 2000

In this paper, we review several two-stage randomized response techniques for gathering self-report data when persons are asked sensitive question. Also efficiencies and privacy protections based on the two-stage randomized response procedures are compared. Finally, we find optimal parameter conditions.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.620-620
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• 2005

• 환경영향평가
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• 제25권6호
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• pp.384-401
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• 2016

본 연구는 하천환경평가체계 구축의 일환으로서 식생 평가 지표 및 평가 기준의 검증을 목적으로 수행하였다. 본 연구를 위해 5개 시험하천을 대상으로 68개의 평가단위에서 총 204개의 식생 표본조사구를 설정하였으며, 표본조사구별 상관-종조성 수준에서 식생군집의 분류 및 현존식생도를 작성하였다. 현존식생도를 기준으로 식생자료의 분석을 통해 표본조사의 적정 규모, 식생 지수의 점수 기준, 식생 군집분류의 표준화, 그리고 식생평가지표의 등급화를 위한 종합 점수기준을 검토하였다. 하천 식생 평가를 위해 개발된 식생 다양도 지수와 식생 복잡도, 그리고 식생자연도 지수로 이루어진 식생평가지표의 종합점수 산정 및 등급화는 타당한 것으로 판단되었다. 식생평가지표의 등급화에 대한 식생지수의 기여도를 분석한 결과 식생자연도 지수가 다른 지수에 비해 보다 큰 역할을 하는 것으로 판단되었으나 세부 식생지수 사이의 상호보완적인 관계가 성립되어 있음을 확인할 수 있었다. 또한, 선행 연구에서의 기준의 재검토 및 식생군집 분류의 표준화 작업 등을 통해 개정된 기준을 적용한 결과 식생평가등급 간 변별력이 크게 확보되었음을 확인 할 수 있었으나, 하천구간의 유형에 따른 식생 지수 및 식생평가지표의 등급화는 큰 차이가 없는 것으로 나타났다.

• International Journal of Advanced Culture Technology
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• 제6권3호
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• pp.178-186
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• 2018

Generally, in terms of the development of irrigation scheme, the efficient water resource management that supplies the irrigation water in consideration of the required time and accurate quantity to grow the crop should be conducted. The water resource assessment should precede to supply the irrigation water efficiently. The water resources assessment is divided into the water requirement analysis and the water availability assessment. In case of Korea, the major crop is paddy rice unlike crops of Africa, such as sugarcane, maize, and cassava, etc. Because it is not familiar with the method for upland irrigation development in tropical area, it needs to know the water resources assessment for irrigation scheme development about these crops. The Natama Scheme in Chiradzulu District of the Southern Malawi was selected as study area, which has tropical climate. From the collected meteorological data, the evapotranspiration was analyzed by Penman-Monteith Method and the effective rainfall was analyzed by USDA Soil Conservation Service Method. This study displays the results that for study area, the evapotranspiration varies from 2.80 mm/day to 5.51 mm/day and the effective rainfall varied from 2.1mm to 149.0mm. According to the selected crop (Green Maize, Dry Maize), the unit water requirement (UWR) and water demand (WD) considering the irrigation efficiency, irrigation time and irrigation area were estimated to be $0.00122m^3/s/ha$ and $0.0122m^3/s$ respectively. For the water availability assessment, the runoff of Natama scheme was calculated by specific yield method. The water availability was evaluated through reviewed differences of discharge between $Q80_{intake}$ and Total WD, and the irrigation water can be supplied sufficiently in the existing 10ha of Natama scheme. As a result of reviewing the extensibility of irrigable area, total WD of scheme is $0.02313m^3/s$, and $Q80_{intake}$ is $0.02387m^3/s$ ($Q80_{intake}$ > Total WD). Therefore, Natama scheme can be extended from 10 ha to 17 ha in the dry season in consideration of the $Q80_{intake}$.