• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.95-106
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• 2014

The outer surfaces of free form buildings contain panels with two-directional curvatures. To construct these panels, complex geometric surfaces should be divided into forms and sizes that can be manufactured and constructed efficiently. Because the bigger the curvatures of these panel, the more expensive the construction costs, these complex curvatures should go through optimal process of reinterpretation to minimize the curved surfaces with complex two-directional curvatures, which is called panel optimization. Small construction and design companies have trouble in calculating even rough estimate and cannot adjust expected construction cost of the panels based on comparison of design alternatives in conjunction with panel optimization process due to lack of knowledge and experience. This study conducts the research that can support designers' cost decision-making in the design stage of the free form buildings with respect to the panel optimization process. A 3D commercial application specialized to modeling free form shapes is used for the purpose.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.415-415
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• 2020

국내 농업용수 수요량 산정에 있어서 논벼 수요량은 수정 Penman (Modified Penman: MP) 방법에 의한 증발산량을 기반으로 산정하고 있으나, 최근 국제식량농업기구 (Food and Agriculture Organization of the United Nations: FAO) 및 국내 농진청 등에서는 Penman-Monteith (PM) 방법에 의한 증발산량 산정방법을 채택하고 있다. 따라서 본 연구에서는 논벼 수요량 산정에 있어 우리나라 실제 현장여건에 적합한 논벼 증발산량 산정 방법을 제안하고자 기존에 적용하고 있는 MP 방법과 최근에 국내외적으로 제안되고 있는 PM 방법에 의한 논벼 수요량 산정 결과를 실질적으로 벼 생산에 공급된 저수지 공급량 자료와 비교 분석을 통해 현장 적용성을 평가해 보았다. 이를 위해 본 연구에서는 농진청에서 PM 증발산량 작물계수를 도출한 현장실험지구를 포함하는 호남지역을 대상으로 저수지 100 만톤 이상의 한국농어촌공사 관리지역 중 농업용수 공급량 자료가 신뢰성 있는 대표지구를 선정하였다. 농업용수 실제 공급량 자료를 기반으로 두 증발산량에 의한 논벼 수요량 산정 결과를 비교 분석한 결과, MP 방법에 의한 수요량이 PM 방법에 의한 수요량 보다 높게 나타났으며, 따라서 MP 방법에 의한 수요량이 PM 방법에 의한 수요량 보다 농업용수 공급량과의 차이가 작게 나타나는 경향을 보였다. 대체적으로 강우량이 적은 지역에서 농업용수 공급량 및 논벼 수요량이 높게 나타났으며, 이러한 결과는 공급량과 수요량간의 관계에도 영향을 미쳐 강우량이 많은 지역에서 강우량이 적은 지역에 비해 농업용수 공급일수가 감소함으로써 공급량과 수요량과의 차이가 적어지는 경향을 보였다. 본 연구 결과로 농업용수 공급량을 기준으로 논벼 수요량 산정에 있어 증발산량 산정방법은 안정적인 농업용수 공급계획과 수리시설 설계에서의 이수안전도 확보차원에서 MP 방법을 채택하는 것이 더 바람직 할 것으로 사료된다. 추가적으로 논벼 수요량 산정은 증발산량 산정방법 외에도 유효우량 산정방법, 수로손실, 재배관리손실 등의 다양한 관련 인자들의 영향을 받기 때문에 증발산량 산정방법과 더불어 이들 인자들에 대해서도 종합적인 평가를 실시하여 논벼 수요량 산정 결과의 신뢰성 확보가 요구된다.

• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.65-72
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• 2013

While growth of domestic CM market has slowed down due to economic recession, it recently shows sign of scale as some public agencies are relocating their headquarters. Since the introduction of CM system, a number of client organizations have acquired construction project management capabilities, however, sufficient efforts are not made to estimate the size of construction project management organization. This study drew a method for estimating the size of the organization managing construction project by utilizing statics analysis and project costs per member based on 10 public construction projects and tried to review applicability through case studies. With this study, we would like to make a contribution to achieving smoother work performance and success of the construction project by estimating and allocating proper scale of management workforce.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.460-460
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• 2021

각종 오염물질이 수계로 유입되어 침강하면 하상에 퇴적되는데 이 오염된 퇴적물 중 질퍽한 콜로이드상의 물질을 오니토라 일컫는다. 이 오염물은 저장소 및 물환경의 변화에 따라 수질 악화의 직접적인 원인이 될 수 있는 인, 질소 등의 영양염류를 수중으로 재용출시킬 수 있는 비점오염원 종류 중 하나이다. 하천 준설은 하천에서 저수용량 확보와 하상 유지관리 및 골재확보, 수질 개선을 위해 토사를 제거하고 그 토사를 운반선에 의하여 운반하여 지정된 투기장에 투기하는 일련의 공사를 말하며, 이를 통하여 비점오염원인 오니토를 직접적으로 제거할 수 있다. 준설의 필요성 판단 및 수질개선 효과를 모니터하기 위해서는 하천의 수질과 유량을 조사해야 한다. 이때 대상구간이 요구하는 수질 기준에 부합하지 않으면 오염퇴적물 준설 기준을 통해 준설이 필요한 구간 및 사업량을 결정한다. 준설 사업량의 경제적 타당성을 정량적으로 검증하기 위해 대상 구간을 준설을 하지 않을 시 오니토가 상시 용출된다는 가정하에 물재생시설로 이 오염물을 정화했을 때의 비용을 준설 사업비와 비교하였다. 본 연구에서는 하천공사 표준시방서(2007)에 제시된 오염퇴적물 준설 기준을 만족하는 서낙동강수계의 준설 계획 지구에 대한 계획 사업비와 해당 지구 하류에 위치한 물재생시설의 정화능력 및 운영비를 비교해 하천 준설 사업비에 대한 편익을 산정하였다.

• Journal of the Society of Disaster Information
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• v.9 no.2
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• pp.195-205
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• 2013

Construction Management means a comprehensive plan of given the resources and the operation of the elements to complete the construction within the construction period. The construction period of these shall be determined by calculation based on reliable initial business. However, in actual field, inaccurate task duration is determined to the intuitive judgments of representative, reference of a similar project construction period of the past. As previous studies for the improvement of existing methods, This study presented a standard model that can be utilized in the early stages of construction projects for the TBM method operating by diameter (2.6m, 3.0m, 3.5m, 5.0m, 8.0m), and This study presented and calculated construction period which can estimated quickly the entire outline the construction period Therefore, When performing TBM construction work in the future, the total construction period which presented and analyze by TBM diameter, can be used as a useful material which plan and manage construction contracts, construction estimating, construction planning to the basic planning stage, and the basic design stage.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.67-77
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• 2012

O Having a highly reliable plan for the process and estimating an accurate construction period during the early stages of a construction project can prevent falsifying the plan and reduce the occurrence of construction delays. Moreover, it allows a succession of swift and accurate decisions to happen. The difficulty in obtaining an accurate estimate of the construction period is especially prominent in high-rise building projects because the works involved are very complicated and costly. As such, it is important that research is done to find out the impacts a reliable plan and good estimate of the construction period can bring with regards to the monthly work efficiency and success of a high-rise building project. However, due to the difference in climatic conditions at high altitude and surface level, the current way of calculating work efficiency in a typical project is inaccurate for a high-rise building project. With that, this paper aims to compute the work efficiency with height, taking into consideration the change in climatic elements at different working heights. A comparison of the results according to the climatic features of each city can also be done in this paper. According to the results calculated in work altitudes, the work efficiency in Busan falls the most. On the other hands, the work efficiency in Seoul falls the least. The reason these results are shown is the influence of wind speed at high altitude. The estimation of work efficiency at high altitude would be used for estimating construction period, feasibility studies, and selecting a city of high-rise building projects.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.167-178
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• 2000

An experimental study on step up filling method is carried out to reinforce the Yano method which is widely used to estimate volume ratio and self-weight consolidation settlement in reclamation area. This method considers actual reclamation construction in which dredged clay is continuously filled and rising of deposit height is presented as a result of volume decrease by height rising and self-weight consolidation. It measured the relationship between filling velocity and deposit rising velocity; calculated the total filling height which is needed to achieve the planned final deposit height, and its solid height and the time which is taken to finish the planned final deposit height; and on the basis of these calculated parameters, predicted the self-weight consolidation and volume change ratio in reclamation construction. Yano method is also used to predict the same conditions. 29.8% in self-weight consolidation, 31.1% in volume ratio, 40% in void ratio and water content is underestimated in Yano method compared to step up filling method.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.349-352
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• 2008

Weather condition is the uncontrolled factor to influence the project duration. Determining non-working days due to it incorrectly leads to often change the project duration and increase the total cost as well as causing the dispute among stakeholders. When making decision of non-working days, it is important to consider the expert's experience according to the characteristic of the site and local area. Therefore this paper presented the method to estimate non-working days due to wether condition by using fuzzy numbers reflecting expert's subjective experience.

• Journal of the Korea Institute of Building Construction
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• v.12 no.1
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• pp.108-114
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• 2012

Escalation method examining the changes in price index has been widely utilized in public construction projects. The previous escalation method determined estimated changes in price based on the average unit price of contract items over a period of time. In relation to this method, the issue has been raised that the fluctuation rates of previous method show different trends compared with other related price indices, as the influence of the small group of contract items with large unit prices overwhelms the others. This research suggested an improved escalation method which estimates the fluctuation rate by examining the changes in CCI (construction cost index) and applies it to the total amount or the partial amount deducted for labor cost in price escalation for previous bid price method. To verify the improvement, a case study is conducted on an educational facility, and the fluctuation rate was estimated in two different base periods (short term, long term). The results over the long term showed similar tendencies to those of related price indices, as well as significant differences in fluctuation rates compared to those of the previous method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.2
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• pp.227-234
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• 2006

Ministry of construction & transportation is operating for the soil and rock information system and is considered to accurate application of soil conversion factor that is essentially necessary for accurate calculation of earth volume. Since the balance of cutting earth in public work, the plan of spoil bank or borrow pit are directly related to construction costs, accurate calculation of earth volume and efficient scheme of haul are important. As such, this study has provided methods that can acquire information that is more rapid, applicable to job sites, and trustworthy by comparing resultant values of photogrammetry, laser scanning, or inside job site experimentations, and calculated soil conversion factor by applying photogrammetry and laser scanning methods for hard rock that has difficulty in calculating soil conversion factor. The study can provide alternatives that can resolve the problems of unbalanced earth volume that may arise in applying to plans the earth conversion factor that relies on planning books and experience without considering the characteristics of job site earth, and can establish its relevancy by calculating soil conversion factor for hard rock that has relative difficulties in doing inside or job site testing.