• Journal of Construction Engineering and Project Management
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• 제3권2호
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• pp.58-65
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• 2013

Earthwork activities are typically performed by heavy duty diesel (HDD) construction equipment that consumes large quantities of diesel fuel use and emits large quantities of pollutants, including nitrogen oxides (NOx), particulate matters (PM), hydrocarbon (HC), carbon monoxide (CO), and carbon dioxide ($CO_2$). This paper presents the framework for a model that can be used to estimate the production rate, activity duration, total fuel use, and total pollutants emissions for earthwork activities. A case study and sensitivity analysis for an excavator performing excavations are presented. The tool is developed by combining the multiple linear regressions (MLR) approach for modeling the productivity with the EPA's NONROAD model. The excavator data from RSMeans Heavy Construction Data were selected to build the productivity model, and emission factors of all type of pollutants from NONROAD model were used to estimate the total fuel use and emissions. The MLR model for the productivity rate can explain 92% of the variability in the data. Based on the model, the fuel use and emissions of excavator increase as the trench depth increase, but as the bucket size increase, the fuel use and emissions decrease.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.660-670
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• 2009

Neighboring construction becomes mainstream of Ground excavation in downtown area. This causes the displacement, deformation, stress condition, etc of the ground surroundings. Therefore Neighboring construction have an effect on Neighboring structure. All these years a lot of Neighboring construction carried out, and the accumulation of technology also get accomplished. But earth retaining structure collapse happens yet. Types of earth retaining structure collapse are 12. 1. Failure of anchor or strut system, 2. Insufficiency of penetration, 3. H-pile Failure on excessive bending moment, 4. Slope sliding failure, 5. Excessive settlement of the back, 6. Deflection of H-pile, 7. Joint failure of coupled H-pile, 8. Rock failure when H-pile penetration is rock mass, 9. Plane arrangement of support systems are mechanically weak, 10. Boiling, 11. Heaving, 12. Over excavation. But field collapses are difficult for classification according to the type, because collapse process are complex with various types. When we consider the 12 collapse field, insufficient recognition of ground condition is 4 case. Thorough construction management prevents from fault construction. For limitations of soil survey, It is difficult to estimate ground condition exactly. Therefore, it should estimate the safety of earth retaining system, plan for necessary reinforcement, according to measurement and observation continuously.

• 한국건설관리학회논문집
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• 제10권4호
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• pp.50-57
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• 2009

공공 건설사업의 계약에 있어 합리적이며 적정한 예정가격의 산정이 가장 중요한 요소라 할 수 있다. 공공 공사 예정가격 산정 근거로 사용되어 온 표준품셈과 더불어 실적공사비 제도를 단계적으로 확대 도입키로 했다. 본 논문에서는 과거에 낙찰되었던 계약단가 뿐 아니라 모든 입찰단가 자료를 활용하여 산출한 실적단가의 변동패턴을 분석하여 예측하는 일련의 절차 및 방법론을 제시하였다. 본 연구에서는 신뢰성 있는 자료 확보를 위해 저가입찰 등과 같은 전략적 입찰단가를 제거한 실적단가를 활용하여 시계열 자료를 구성하여 이 시계열을 웨이블릿 분석을 통해 변동 패턴과 추세를 파악하고 신경망을 이용하여 공사비를 예측하는 방안을 주요하게 다루고 있다. 건설 공사비는 매우 다양한 특성을 내포하고 있으므로 그 예측이 어려울 뿐만 아니라 그 오차 또한 매우 클 것으로 예상된다. 이에 본 연구에서는 웨이블릿 변환을 통하여 다양한 특성의 변동을 찾아내어 이를 예측에 이용함으로써 예측력을 높이고자 하였다. 다만 시계열이 매우 단기간의 자료로 구축되어 변동의 양상이 정확하게 분석될 수 없었으나 지속적으로 실적공사비 자료기 축적되어 장기간의 자료를 바탕으로 시계열이 구축된다면 향후 수행될 건설사업의 기획 시 개략적인 공사비 산출에 참고할수 있는 유용한 자료로 활용될수 있을 것이다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2004년도 학술대회지
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• pp.15-19
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• 2004

The production of waste concrete is increased continuously by urban renewal, reconstruction, remodeling, and so on. So the positive use of recycled aggregate concrete is needed. Research for recycled aggregate concrete that use recycled aggregate from the mid-80s to solve environmental problem of aggregate insufficiency and waste concrete is consisting vigorously. However, specifications and mix design about waste concrete's use are evading use of recycled aggregate concrete yet in spot being not taken a triangular position. Therefore. it analyze existing research data for recycled aggregate concrete collection to develop strength estimate program in this research. Recycled aggregate concrete's strength estimate program if specifications and mix design about recycled aggregate concrete are taken a triangular position to foundation recycled aggregate concrete's practical use to increase judge.

• 한국건설관리학회논문집
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• 제5권6호
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• pp.138-145
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• 2004

공사에 소요되는 기간은 시설물의 품질과 비용에 직접적인 영향을 미치지만, 고등학교 시설공사의 경우 경험과 직관에 의거하여 공기를 산정하고 있어 공사수행과정에서 계약당사자 간에 분쟁이 많이 발생하고 있다. 본 논문은 고등학교 시설공사에 소요되는 기간의 산정에 영향을 미치는 다양한 요인을 분석하여 공기 산정기준을 제안하는 것으로, 인천지 역에서 최근에 개교한 고등학교의 실적자료를 수집하여 다중선형 회귀분석 하였다. 회귀분석 결과로 얻은 순 공사기간에 인천지 역의 기후특성을 고려하여 산정한 작업불가능기간을 더하여 총 공사기간을 산출 하였다. 본 논문에서 제안한 공기 산정식은 공사발주 및 계약 시 계약공기를 정확하게 산정 하는데 도움을 줄 수 있을 것이다

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.349-352
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• 2003

우리와 미국의 건설사업 환경 및 제도가 다른 상황에서, EVMS의 도입은 적지 않은 혼란을 가져올 수 있다. 미국의 경우는 수십년간의 많은 경험을 바탕으로 EVMS를 적용하고 있으나, 국내는 이제 EVMS를 도입하고 활용하기 시작하는 단계이기 때문이다. 이에 본 연구에서는 EVMS 도입상의 문제점 중에서도 최종공사비 산정시 성과지수의 사용에 대한 문제를 다루어 보고자 한다. 본 연구에서는 국내${\cdot}$외의 연구에서 사용된 지수를 검증대상 지수로 보고. 이를 EVMS방식이 적용된 국내 아파트 프로젝트에 통계적으로 적용해 보았다. 이를 통하여, 국내 적용될 수 있는 지수들을 평가하고 지수들의 경향 및 특성을 파악할 수 있었다.

• Architectural research
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• 제22권2호
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• pp.63-73
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• 2020

This paper reports problems of current working environment on construction site in South Korea from a female laborers' point of view and proposes solutions to improve the environment. To investigate and analyze the problems, a questionnaire survey and a focus group interview were conducted with 341 engineers and 557 laborers. Among them female engineers and female laborers were 51 and 136 respectively. Findings are the facilities related with welfare facilities such as lavatories, shower rooms, lounges and changing room, etc. for women were not sufficient and even not installed only for women because all of the planners for the facilities were men and The Standard of Estimate does not consider gender distinction. The data on the trade and the number of female laborers were not recorded and this study confirmed the number and the proportion of female laborers according to construction progress i.e. the proportion of female laborers were 0% ~ 11% (average 6%) at 26 construction sites having 2% ~ 92 % construction progress. In order to solve these problems, gender education for the welfare facility planner is required and the current Standard of Estimate should be revised considering female laborers after collecting the site data for the number of female laborers according progress and the increase in the construction cost should be reflected in the contract amount accordingly. Conclusively temporary work planning related with welfare facilities should be established and conducted in terms of gender equality at construction sites. In addition, improving working environment on construction sites for female laborers will enhance the company's image and also helping solve the labor shortage problem by women laborers engaging in construction industry easily.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2001년도 춘계 공동학술발표회
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• pp.206-207
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• 2001

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.417-424
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• 2009

For a construction project to progress smoothly, effective cost estimation is vital, particularly in the conceptual and schematic design stages. In these early phases, despite the fact that initial estimates are highly sensitive to changes in project scope, owners require accurate forecasts which reflect their supplying information. Thus, cost estimators need effective estimation strategies. Practically, parametric cost estimates are the most commonly used method in these initial phases, which utilizes historical cost data (Karshenas 1984, Kirkham 2007). Hence, compilation of historical data regarding appropriate cost variance governing parameters is a prime requirement. However, precedent practice of data mining (data preprocessing) for denoising internal errors or abnormal values is needed before compilation. As an effort to deal with this issue, this research proposed a statistical methodology for data preprocessing and verified that data preprocessing has a positive impact on the enhancement of estimate accuracy and stability. Moreover, Statistically Preprocessed data Based Parametric (SPBP) cost models are developed based on multiple regression equations and verified their effectiveness compared with conventional cost models.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.133-137
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• 2017

Nuclear power plants in Korea are usually built based on a duplicated model; so the project cost data of the preceding unit can be used as reference when estimating the project cost for the succeeding unit. However, since the contracting method is oriented towards the price, empirical factors such as making top-down estimations using the reverse calculation method based on the completion cost of the preceding unit is dominant. In order to develop a project cost database to resolve such problems, the detailed cost boundary of the project cost data must be categorized by project and by system. This study proposes a method to connect the code of account with the base quantities and the IAEA account, and proposes a database structure for the development of a project cost estimation system. The estimation system developed in the future is expected to utilize the proposed project cost data structure.