• Title/Summary/Keyword: Estimation Methodology

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Development of a Conceptual Estimate Methodology for Plant Construction Projects (플랜트 건설 프로젝트를 위한 개산견적 방법론 개발)

  • Kim, Hyun-Joong;Choi, Jaehyun
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.1
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    • pp.141-150
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    • 2019
  • In the overseas plant construction market, the domain construction firms' construction capability has been greatly improved, but the capability of project management is evaluated to be insufficient compared to the technical aspect. Project management capabilities from the initial planning stage of project execution are regarded as the core competence of advanced construction companies. Among them, it is urgent to improve the capacity of conceptual estimate for domestic companies. In this study, the researchers surveyed and analyzed the methodology of estimating project cost in the planning phase of the plant project and developed an estimation method by conducting a case study analysis. Based on the logic of the cost index and parametric estimation method among the existing estimation methodology, the estimation tool was developed by deriving the input and output variables tailored to the plant project. The validity of the proposed methodology was evaluated by comparing the accuracy between the project estimate amount of the case project and the actual project amount. In order to increase the utilization of the developed conceptual estimate methodology,for plant construction project, it is necessary to systematize the data of the historical project data. Increasing the accuracy of future project cost estimates is directly related to increasing project award and profitability of the domestic construction company.

Earthquake Loss Estimation of Buried Pipeline Considering Permanent Ground Deformation due to Liquefaction (액상화.영구지반변형을 고려한 지중매설관로의 지진피해 평가)

  • Kim, Tae-Wook;Lim, Yun-Mook;Kim, Moon-Kyum
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.102-109
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    • 2005
  • In this study, a prototype model of earthquake loss estimation method will be proposed for the quantitative and qualitative damage evaluation of buried pipeline subjected to Permanent Ground Deformation(PGD) due to liquefaction. With this objective, domestic and foreign status of the arts related with earthquake loss estimation method is summarized at first. Domestic development of computer aided earthquake loss estimation method seems to be difficult for the time being. Thus, referring to HAZUS : Earthquake Loss Estimation Methodology which is developed by FEMA (Federal Emergency Management Agency) and NIBS (National Institute of Building Sciences), earthquake loss estimation procedure of buried pipeline subjected to PGD due to liquefaction are proposed, and then exemplary loss estimation are executed. Considering that there have been no practical earthquake loss estimation method and procedure in Korea, the research accomplishments such as above are considered to be helpful for the substantial development of earthquake loss estimation method of buried pipeline subjected to PGD due to liquefaction.

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An electromechanical impedance-based method for tensile force estimation and damage diagnosis of post-tensioning systems

  • Min, Jiyoung;Yun, Chung-Bang;Hong, Jung-Wuk
    • Smart Structures and Systems
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    • v.17 no.1
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    • pp.107-122
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    • 2016
  • We propose an effective methodology using electromechanical impedance characteristics for estimating the remaining tensile force of tendons and simultaneously detecting damages of the anchorage blocks. Once one piezoelectric patch is attached on the anchor head and the other is bonded on the bearing plate, impedance responses are measured through these two patches under varying tensile force conditions. Then statistical indices are calculated from the impedances, and two types of relationship curves between the tensile force and the statistical index (TE Curve) and between statistical indices of two patches (SR Curve) are established. Those are considered as database for monitoring both the tendon and the anchorage system. If damage exists on the bearing plate, the statistical index of patch on the bearing plate would be out of bounds of the SR curve and damage can be detected. A change in the statistical index by damage is calibrated with the SR curve, and the tensile force can be estimated with the corrected index and the TE Curve. For validation of the developed methodology, experimental studies are performed on the scaled model of an anchorage system that is simplified only with 3 solid wedges, a 3-hole anchor head, and a bearing plate. Then, the methodology is applied to a real scale anchorage system that has 19 strands, wedges, an anchor head, a bearing plate, and a steel duct. It is observed that the proposed scheme gives quite accurate estimation of the remaining tensile forces. Therefore, this methodology has great potential for practical use to evaluate the remaining tensile forces and damage status in the post-tensioned structural members.

A Study on the ICT Construction in Korea through Benchmarking Japanese Systems and Policies - Focused on Earthwork (일본의 제도·정책 벤치마킹을 통한 국내 건설 ICT 시공 방안에 관한 연구-토공사를 중심으로)

  • Park, Soo-Hyun;Kim, Jeong-Hwan;Seo, Jong-Won;Shim, Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.4
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    • pp.429-439
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    • 2021
  • In order to cope with the decrease of construction manpower caused by the aging population and to improve construction productivity, Japanese Ministry of Land, Infrastructure, Transport and Tourism has been promoting construction methodology using ICT (Information & Communication Technology) since 2016. The ministry has established and implemented new cost estimation standards, delivery systems, and government support policies to boost automated earthwork using ICT, and is expanding the types of automated construction methodology applied at the construction sites. To utilize ICT at construction sites in Korea, as in case of Japan, laws, systems, and policies should be readjusted first. By comparing the ICT-related systems and policies between Japan and Korea, this paper scrutinizes critical benchmarking factors. As a result, we have reached the conclusion that in order to promote ICT methodology at Korean construction sites, Korean government should establish ICT-related cost estimation standards, delivery systems, and economic support policies in advance.

Analysis of Forest Carbon Offset Credits from Forest Management Project based on to the Korean Forest Carbon Offset Standard and the VCS Methodology - Case Study on the Methodology for Forest Management through Extension of Rotation Age - (국내 산림탄소상쇄 운영표준 및 VCS 방법론에 따른 산림경영 사업의 산림탄소흡수량 차이 분석 - 벌기령 연장 사업 방법론을 중심으로 -)

  • Kim, Young-hwan
    • Journal of Climate Change Research
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    • v.8 no.4
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    • pp.369-375
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    • 2017
  • In this study, it was intended to compare the two methodologies for forest management project through extension of rotation age: Korean Forest Carbon Offset Standard (KFOS) and Verified Carbon Standard (VCS). The amount of carbon removals and offset credits based on the two methodologies and their trends were analyzed in this study. The major difference between two methodologies were found at the process of estimation of baseline carbon removals. For instance, average carbon stock during the project period was used for estimation of baseline carbon removals in KFOS, while average carbon stock change during the 100 years was used in VCS. Due to the different approach for estimation of baseline carbon removal, the estimated offset credits were also different according to the two methodologies. In this study, 15 project scenarios were considered for comparison of two methodologies : 5 major coniferous stands in Korea (Pinus densiflora in Gangwon region, Pinus densiflora in Central region, Pinus koraiensis, Larix leptolepis, Chamaecyparis obtusa) with 3 project periods (30, 35, 40 years). The results showed that estimated carbon offset credits based on the KFOS methodology were higher for all 15 scenarios compared to those based on the VCS methodology. The KFOS showed a steep decline in the annual offset credit as project period gets longer, thus it is not desirable for projects with longer period. VCS is more acceptable for longer projects with a small difference according to the project periods. The results also indicated that Pinus densiflora in Gangwon, Pinus koraiensis, and Larix leptolepis are more desirable species for forest management project through the extension of ration age.

A Classification Methodology of Structural Types of RC Buildings for Improving Seismic Fragility Functions (지진취약도 함수 개선을 위한 철근콘크리트 건물의 구조 유형 분류 방안)

  • Kim, Taewan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.24 no.6
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    • pp.285-292
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    • 2020
  • The methodology classifying structural types of concrete buildings in the existing seismic fragility functions is too simple to estimate the fragility of existing residential buildings and neighborhood living facilities, especially those below five stories. Their structural types are dependent on information contained in the building register such as main use, total floor area, story, permission date, and first story floor area of the individual building. All of this information is not considered for classifying types in the existing functions; therefore, the goal of this study was to suggest a methodology that classifies structural types of concrete buildings by utilizing such information. The results of this study showed that the suggested methodology can classify structural types better than the existing methodology. Nevertheless, there is still a need to simplify the methodology because fragility estimation demands quickness rather than accuracy.

The Evaluation Model for Natural Resource Conservation Areas - Focused on Site Selection for the National Trust - (자연자원 보전지역의 평가모형 - 내셔널 트러스트 후보지 선정을 중심으로 -)

  • 유주한;정성관
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.2
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    • pp.39-49
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    • 2002
  • The purpose of this study is to propose an objective and rational methodology for the selection of proposed sites far the National Trust(NT), which is the new alterative proposal far the conservation of natural environments destroyed by injudicious land development and economic growth. That is to enforce many analysis for the effective estimation of rare ecological and landscape resources and to propose a model based on estimation and united indicators. Using the estimative model, we apply it to the selection of the proposed site in micro scale and simultaneously offer the basic methodology of effective and systematic land conservation in macro scale. The results of this study are as follows: 1) The results of analysis for the reliability of estimative items and indicators, presented no problem in that the coefficient of reliability was over 0.7. 2) The correlation measure of the estimative indicator indicated that 'succession'and 'regenerating restorability' were highly correlative in the item of plants. Another three items showed a tendency to be alike. 3) The results of factor analysis on the characteristics of indicators, classified plants into four categories including a stable factor. The item of animals was classified as a stable and rare factor. The item of landscape was classified as a physical and mental factor and the environment as a pollutional and conditional factor. 4) The model of estimation created through factor analysis was valid for the approval of the regression model because significant probability was 0.00. When we consider the NT proposed site as a complex body that is composed of diverse natural and manmade resources, certainly the synthetic methodology of estimation is needed. If these studies are carried out, NT sites will be selected more rationally and effectively than at present. Consequently, they have the potential to play a core role of natural ecosystem conservation in Korea.

Estimation of Ultimate Lateral Load Capacity Using CPT Results Considering Lateral Soil Pressure Distribution (수평토압분포를 고려한 CPT 기반의 말뚝극한수평지지력 산정)

  • Kim, Min-Kee;Kyung, Doo-Hyun;Hong, Jung-Moo;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.25 no.2
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    • pp.37-44
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    • 2009
  • In this study, estimation methodology for the pile of ultimation lateral resistance, pu, and ultimate lateral capacity, Pu, is based on the CPT cone resistance $q_c$. Preexistent methodologies for ultimate lateral resistance and ultimate lateral capacity have been generally represented with relative density, vertical effective stresses, and various $K_0$ values which are important for analyzing sandy soil. These methodologies, however, did not consider the horizontal effective stress and the effects of construction site conditions. Therefore, CPT-based methodology for the estimation of the ultimate lateral pile load capacity Hu was proposed. Calibration chamber test results were analyzed and compared with calculated results. The proposed estimation methodology for the pile of $p_u$ can be effectively utilized as alternative to preexistent methods.

A Study on the Estimation Analysis Methodology of the Optimum Economic Life-Span of Buildings (건축물의 최적 경제수명 추정분석 방법론에 관한 연구)

  • Choi, Jun-Young
    • Journal of the Korean Society of Industry Convergence
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    • v.6 no.3
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    • pp.223-230
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    • 2003
  • Generally, the life-span of a multi-housing complex is over 50 years, but in reality they are usually demolished after 20 years in spite of its remaining life expectancy. Thus, this research focuses on the estimation of the optimum economic life-span of a multi-housing complex. To estimate the minimum total cost point of start to finish of a multi-housing complex, we'll apply MAPI(Machinery and Allied Product Institute) and LCC(Life Cycle Cost) theory.

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A Note on a New Two-Parameter Lifetime Distribution with Bathtub-Shaped Failure Rate Function

  • Wang, F.K.
    • International Journal of Reliability and Applications
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    • v.3 no.1
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    • pp.51-60
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    • 2002
  • This paper presents the methodology for obtaining point and interval estimating of the parameters of a new two-parameter distribution with multiple-censored and singly censored data (Type-I censoring or Type-II censoring) as well as complete data, using the maximum likelihood method. The basis is the likelihood expression for multiple-censored data. Furthermore, this model can be extended to a three-parameter distribution that is added a scale parameter. Then, the parameter estimation can be obtained by the graphical estimation on probability plot.

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