• 농촌계획
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• 제26권4호
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• pp.67-79
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• 2020

As globalization, international cooperation has grown in importance. In accordance with this trend, Korea has been receiving high demands from international organizations about expanding the scale of Official Development Assistance(ODA) in line with its improved national status. In addition, in the economic aspect of Korea, the ODA project is expected to provide new growth opportunities in the mid- to long-term by promoting cooperation with developing countries. Uganda is an area with high strategic value due to good agricultural conditions and favorable geographical conditions. The poultry industry is a business that is generally carried out to the Ugandan, but due to economic problems such as initial investment cost, most of them have raised poultry on a small scale which is not enough for main income. This paper proposes the construction and operation plan of adapting to small poultry farms in the village-intensive type to sustainable income for residents in Uganda through ODA project in Korea's agricultural technology. The economic feasibility was analyzed from the long-term perspective when the initial construction cost was supported or not and the poultry species ratio was adjusted in terms of initial and operating costs. Economic analysis was performed using Net Present Value(NPV) method. As of after 10 years, when operating in the form of shifting kuroiler to layers, it was estimated to earn about 700,000 ugx more than when only kuroiler is raised, and it is able to reduce about 14 million ugx from the initial cost than when only raising layers. As of 20 years, the most profitables scenario was the breeding of 100 kuroilers and 400 layers methods. however, this case was anlayzed to be unsuitable for Uganda farmers, with initial costs more than three times higher than the shifting method of the kuroiler to layers. If the initial construction cost is supported by ODA project, the initial investment cost can be recovered in the first year with the shifting method, whereas raising only layers take two years to recoup the cost. In the meantime, when studying livestock industry in Uganda, it was examined by relying on statistical data, but this paper is meaningful in that it predicted how much it is economically effective based on field experience.

• 한국건설관리학회논문집
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• 제17권5호
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• pp.120-129
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• 2016

이용자 비용은 SOC 시설물의 효율적 자산관리를 위한 LCCA에서 시설물의 생애주기, 관리자 비용 그리고 할인율과 함께 반드시 고려되어야 하는 주요한 분석 항목이다. 특히, 도로분야에서는 청소 및 유지보수 등의 공사구간(Work zone)으로 인해 이용자들에게 막대한 지체비용이 발생되는 경우가 많으며, 이와 같은 경우 관리자는 보다 합리적인 의사결정을 위해 관리자비용 뿐만아니라 이용자비용까지도 고려해야만 한다. 그러나 최근까지도 대부분의 의사결정 단계에서 이용자 비용은 고려되지 않고 있으며, 이에 관한 연구들도 활발하지 못한 실정이다. 본 연구에서는 교통류 모형과 교통시설 투자 평가 지침의 직접편익 산정 모델을 이용하여 의사결정 단계에서 필요한 이용자 비용 및 지체비용을 산정 하는 방법론을 제안한다. 그리고 2014년 실제 유지보수가 시행되었던 국도 4개구간에 대해 VISSIM을 이용하여 교통류 모형을 추정하고 제안된 방법론을 토대로 이용자 비용 및 지체비용을 산정하였다. 분석결과, AADT 약 3만대의 A구간은 공사구간 발생 전 평균 17,569천원/$km{\times}day$의 이용자 비용이 발생하는 것으로 분석되었으며, 유지보수로 인해 1차로를 차단 할 경우 추가적으로 평균 10,193천원/$km{\times}day$(158%)의 지체비용이 발생하는 것으로 분석 되었다. AADT 약 2만대의 B구간과 D구간에서는 각각 1,507천원/$km{\times}day$(115%), 1,985천원/$km{\times}day$(119%)의 지체비용이 발생되는 것으로 분석되었으며, AADT 약 1만대의 C구간에서는 262천원/$km{\times}day$(105%)의 지체 비용이 발생하는 것으로 나타났다. 본 연구의 결과는 교통류 모형을 시뮬레이션 기반으로 추정함으로서 실제 적용에는 한계가 있다. 향후 실제 관측 자료를 이용한 적정성 높은 모형의 개발과 시뮬레이션 검증을 통해 적용 가능성을 높이는 연구가 필요할 것으로 판단된다.

• 한국산림과학회지
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• 제83권3호
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• pp.299-310
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• 1994

본 연구는 강원도 춘천군에 위치한 임업진흥촉진지역(林業振興促進地域)을 대상으로 총수확비용(總收穫費用)(임도개설비(林道開設費)+집재비(集材費))을 최소화하는 양방향(兩方向)-단계집재(段階集材) 및 이단계집재(二段階集材)를 위한 적정임도간격(適正林道間隔) 및 임도밀도(林道密度)를 산출하였다. 이때의 임도개설비(林道開設費)는 km당 천만원부터 6천만원까지이다. 그 결과는 다음과 같다. 양방향(兩方向)-단계집재(段階集材)에서는 케이블 크fp인이 적합하며, 적정임도간격(適正林道間隔)은 1,698m~4,192m,평균 3,087m이며, 임도밀도(林道密度)는 3.44m/ha~8.44m/ha, 평균 5.12m/ha로 산출되었다. 양방향(兩方向)-이단계집재(二段階集材)에서 중지형(中地形)은 중형집재기와 로깅부기의 조합기종이 적합하며 임도간격(林道間隔) 1,483m~3,481m, 평균 2,589m로서, 임도밀도(林道密度)는 4.05m/ha~9.46m/ha, 평균 5.90m/ha로 산출되었다. 또한 급지형(急地形)은 중형집재기와 진성윈치의 조합기종이 적합하며, 임도간격(林道間隔) 1,693m~3,982m, 평균 2,960m로서, 임도밀도(林道密度)는 3.68m/ha~8.64m/ha 평균 5.38m/ha로 산출되었다.

• 터널과지하공간
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• 제20권4호
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• pp.233-240
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• 2010

지하 원유 저장공동에서 두 공동간의 혼유 방지를 위해 설치되는 더블 플러그는 구조물 시공 후 더블 플러그 내부를 물로 채운 후에 충수의 누수 정도를 파악함으로써 플러그 기밀성을 평가한다. 만약 예상 누수량이 과소하게 산정되면 시공비용이 증대되고, 과다하게 산정될 경우에는 운영비용이 증가될 수 있으므로 최적의 예상 누수량을 산정할 필요가 있다. 본 연구에서는 더블 플러그(double plug) 주변의 투수특성을 보다 정확하게 반영할 수 있도록 수리 안정성 해석을 수행하였으며, 수리 안정성 해석 및 기존 사례 분석 과정을 통해 플러그 주변의 누수 가능성이 있는 모든 경로에 대한 예상 누수량을 산정하였다. 또한 누수 경로에 대한 누수량을 실측 하여 예상 누수량 산정 결과의 신뢰성을 확인하였다.

• 대한토목학회논문집
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• 제33권4호
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• pp.1693-1705
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• 2013

국내의 수로교는 쌀문화로 상징되는 농업용수를 공급하는 교량으로서 수로교를 개보수하기 위해서는 기본설계를 실시하는 것이 바람직하나 현재 생략되고 있는 실정이므로 이에 소요되는 공사비를 산정할 필요가 있다. 이 연구에서는 2003년 이후 교체한 RC구조 수로교에 대한 실적자료를 기초로 개략공사비 산정 회귀분석(RA) 모델과 사례기반추론(CBR) 모델을 개발하였다. RA 모델의 경우 단순회귀 모델이 다중회귀 모델보다 오차율이 낮았다. CBR 모델의 경우 유전 알고리즘을 이용하였으며 영향요인의 가중치, 편차, 순위조건을 최적화 대상으로 하였고 특히 영향요인 가중치의 범위를 제한하여 수로교 개보수 공사비의 예측 정확도를 제고하였다. RA 모델과 CBR 모델 사이의 오차율은 통계적 차이를 보이지 않았다. 본 논문에서 제시된 수로교 개보수 개략공사비 산정방법은 개보수사업의 시행에 따른 신속한 의사결정을 하는데 활용될 수 있을 것으로 기대된다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1140-1147
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• 2009

Productivity measurement of construction machinery is a significant issue faced by many contractors especially those involved in earthwork projects. Traditionally, equipment production rate has been estimated using data available in manufacturers' catalogues, results of previous construction projects, or personal experience and assessments of the site personnel. Actual production rates obtained after the completion of a project demonstrate the fact that most of these methods fail to provide accurate results and as a direct consequence, may lead to unrealistic project cost estimations prepared by the contractors. What makes this more critical is that in most cases, inadequate cost estimations lead the entire project to exceed the initial budget or fall behind the schedule. In this paper, a linear regression method to estimate bulldozer productivity is introduced. This method has been developed using SPSS-16 software package. The presented method is used to estimate the productivity of Komatsu D-155A1 series which is commonly used in many earthmoving operations in Iran. The data required for the numerical analysis has been collected from actual site observation and productivity measurement of 60 pieces of D-155A1 series currently being used in several earthmoving projects in Iran. Comparative analysis of the output data of the presented regression method and the existing productivity tables provided by the manufacturer shows that when compared to the actual productivity data collected on the jobsite, a significant increase in accuracy and a remarkable reduction of data variance can be achieved by using the presented regression method.

• 농업과학연구
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• 제50권4호
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• pp.785-798
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• 2023

Considering irrigation facilities are currently insufficient and drought vulnerability due to climate change is high, efficient measures are required to secure water supply for field crops. This study, therefore, calculated the water shortage to secure water for representative field crops. An economic analysis was further conducted by comparing the production income to the input cost for each method. Here, five distinct regions were selected to represent each crop-Cheongyang-gun for chili peppers, Yesan-gun for apples, Dangjin-si for cabbages, Seosan-si for garlic, and Goesan for beans. The regions with insufficient water supply were estimated by calculating the water requirements and the supplied water from public groundwater wells for each area. A comprehensive set of four scenarios was presented as a strategy to ensure water security and manage irrigation facilities. These scenarios comprised the maintenance of existing groundwater wells, the construction of new water storage tanks, the installation of additional groundwater wells, and the utilization of surface water. B/C (benefit/cost) analysis was conducted for each scenario. As a result, the construction of water storage tanks was selected as a facility and water management plan in Cheongyang-gun, Dangjin-si, and Seosan-si. The analysis additionally indicated the economic viability of installing surface water utilization facilities in Yesan-gun and developing water storage tanks and groundwater (aquifer) wells in Goesan-gun. The results of this study are considered to serve as foundation data that may be utilized in the selection of water management plans for drought-prone areas in the future.

• 동력기계공학회지
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• 제16권5호
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• pp.13-19
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• 2012

In this paper, the offshore wind farms have been designed by using WindPRO with the help of real wind data measurements at Jeju Costal area by calculating the annual energy production for exact economic evaluation. In order to achieve benefit of wind farm, the annual revenue for power generation have been calculated with SMP and REC value. And construction cost has derived from the real wind farm project case. Also O&M cost has been estimated by OMCE (Operating & Maintenance Cost Estimator) to get accurate cost of wind farm. Economic evaluation of wind farms have been performed by comparing above parameters. In addition, sensitivity analysis calculating the effect of these factors has also been carried out.

• 대한건축학회논문집:구조계
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• 제35권12호
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• pp.181-188
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• 2019

The maintenance of school building is pivotal issue. However, it is difficult to obtain basic analysis data for LCC(Lifecycle Cost) analysis and maintenance planning of school building. Therefore, this study proposed System Dynamics(SD) techniques to make maintenance decisions for school building. The interaction between the major parameters related to the aging of a building, maintenance activities, and cost were expressed in Causal Loop Diagram. Based on this, the formula for the relationship between causal maps was defined and converted to Stock and Flow Diagram. Through the completed SD model the 50-year plan of 214 educational building were tested by considered in account budget, maintainability, and budget allocation opinions. As a result, the integrated SD model demonstrated that it can support strategic decision making by identifying the status class and LCC behavior of school buildings by scenario. According to the scenario analysis, the rehabilitation action of preventive maintenance that primarily repairs the buildings in condition grade C showed the best performance improvement effect relative to the cost. Therefore, if the proposed SD model is expanded to consider the effects of other educational policies, the crucial performance improvement budget can be estimated in the long-term perspective.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1183-1188
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• 2009

Estimating project costs during the early stage of conceptual planning is very important when deciding whether to approve the project and allocate an appropriate budget. However, due to greater uncertainties involved in a project, it is challenging to estimate costs during this initial stage within a reasonable tolerance. This paper attempts to develop a cost-estimate model for public road projects under these circumstances and limitations. In the conceptual planning stage of a road project, there is only limited information for cost estimation, for example, such input data as total length of the route, origin and destination, number of lanes, general geographic characteristics of the route, and other basic attributes. This implies that the model should individuate suitable but restricted information without considering detailed features such as quantity of earthwork and a detailed route of a given condition. With these limited facts, this paper applies a case-based reasoning (CBR) method to solve a new problem by deriving similar past problems, which in turn is used to estimate the cost of a given project based on best-fitted previous cases. To develop a CBR cost-estimate model, the authors classified 8 representative variables, including project type, the number of lanes, total length, road design grades, etc. Then, we developed the CBR model, primarily by using 180 actual cases of public road projects, procured over the last decade. With the CBR model, it was found that the degree of error in estimation can be reasonably reduced, to below approximately 30% compared to the final costs estimated upon the completion of detailed design.