• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.274-277
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• 2006

The EAC(Estimate at Completion) among existing methods, which estimate cost and time effectively, help managers anticipate changeable several results at the point of $15{\sim}30%$ in the project progress. However, this method may cause such some problems as not to consider the periodically changing circumstances caused by construction risks or uncertainties which can affect the cost and time in the project, and to regard collected and accumulated data only as a single value when predicting the results on the progress. Accordingly, it is very difficult to accept the even small range of variability based on the anticipation of EAC. Consequently, the study focuses on the possibility methodology to anticipate time and cost accurately on the way to utilize EVMS(Earned Value Management System), and also suggest the way to perform the right estimation of EAC as considering various risks and uncertainties in construction projects.

• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.25-34
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• 2012

It has been five years since the Post-Construction Sale System of Housing was introduced. The purpose of this study is to identify objectives and effects of the Post-Construction Sale System of Housing and analyze change of profitability at different sales time from a supplier's point of view. Apartment buildings construction projects performed in Seoul are used for the case study. The present value of sales revenues, sensitivity and the present value of expected sales prices are analyzed. According to the findings, first, profits made from a Pre-construction sales system was 5.1%~6.2% higher than those from a Post-construction sales system. Among four plans of a Pre-construction sales system (A, B, C and D plan), sales revenue from the A plan, which takes a deposit at the time of starting construction, was the greatest. Second, increase of the rate of discount and decrease of sales revenues are in direct proportion. The bigger rate of discount leads actual reduction of sales revenues. Third, for the present value of sales revenues reflecting change in basic model construction cost, a Pre-construction sales system showed a little higher than that of a Post-construction sales system by approximately 2%. It should be known that this study suggests profitability of Pre-and Post-construction sales system by clearly measuring them in the supplier's point of view and calculates sales revenues, considering change of a sale price following change of sales time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.314-321
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• 2016

After the 1980s, as the economy was growing rapidly and the real estate market was active, a large increase in population was supplied to the city. Accordingly, the national apartment housing market is located in the form of Urban Housing Culture. On the other hand, with time, the supply apartment houses became superannuated and the residential environment became poor. Therefore, the environment of old apartment houses has been changed to improve by reconstruction. Despite this, reconstruction incurred not only a lot of construction waste, but also problems of environmental degradation, noise, traffic congestion, increasing number of households, and so on. Recently, the housing law has changed, and vertical extension remodeling focused on Small/Medium Town House is underway. This has been changed in response to the demand. This is one of essential parts in the remodeling field for the future, even though it has some problems in how uses existing buildings. Therefore, this study analyzed occurrence risk factor for each type through research materials and case analysis regarding the vertical extension remodeling of apartment housing. In addition, the relative importance was determined through questionnaires and interviews from constructors, designers, and experts in the field.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.147-148
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• 2010

낙후된 도시를 정비하는 방법으로 새로이 등장한 거점확산형 주거환경개선사업은 전면철거방식인 주택재개발사업이내 공동주택 건설방식과 비교하여 지역주민의 재정착 비율이 높고, 기존 도시 조직을 고려하며 점진적으로 개발할 수 있는 기성시가지 정비수법으로 주목받아 왔다. 또한 지역의 침체된 경제를 활성화시키고 황폐화된 구시가지를 회복시키기 위하여 정부에서는 도시의 새로운 경쟁력을 찾고 지역 주민의 삶의 질을 보장하기 위해 지역 주민의 삶의 질을 보장하기 위해 지역 커뮤니티를 근간으로 하는 도시재생사업을 추진하게 되었다. 효과적인 거점확산형 주거환경개선사업을 위해서는 주민참여가 중요하며, 현재에 이르러서는 필수적인 요건이 되었고, 도시계획 역시 주민과 함께 하는 방향으로 변화하게 되었다. 이에 따라 GIS도 주민과 같은 비전문가의 의사결정을 지원하기 위한 도구로 확대되어 활용되고 있다 하지만, 현행 주민참여 방식은 형식적인 수단에 불과하며, 주민 참여도를 높일 수 있는 획기적인 방법은 아직도 연구해야할 과제이다. 따라서 본 연구에서는 커뮤니티의 재생을 목적으로 하는 거점확산형 주거환경개선사업에서 능동적 주민참여를 좀 더 효율적으로 이끌어 내고자 사업정보제공서비스, 주민의사반영 서비스, 쌍방향적 의견교환서비스, GIS 서비스를 제공하는 커뮤니티 재생을 위한 앱 기반 PPGIS 모델을 제안하였다. 최근 스마트폰의 보급률이 급증함에 따라 스마트폰의 활용은 주민들의 관심과 참여 비율의 변화를 크게 가져올 수 있을 것으로 기대되며, 커뮤니티 재생을 위한 스마트폰의 앱 기반 PPGIS 모델은 정책결정자, 전문가 그리고 주민이 서로의 생각을 교환하고 이해하는데 또 다른 유용한 의사소통 도구가 되어 주민의 참여도를 높여 줄 것이라 기대된다 특히, 스마트폰을 많이 사용하고 있는 젊은층의 흥미를 유발하여 참여도가 낮은 젊은층의 참여도를 높이는데 기여할 것이라 여겨진다,

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.377-384
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• 2017

It is generally acknowledged that subcontractors mostly allocate their resources to project relying on their previous experiences, instead of data-based judgement. Installing residential fire protection systems, typically performed by subcontractors, is labor-intensive job and its schedule is frequently changed as the contractor master schedule is often revised. Nevertheless, it is still important for subcontractors to make much effort to improve labor productivity through a thorough planning for scheduling and resource allocation. The purpose of this study is to identify significant factors that affect labor productivity for residential fire protection system installation. For this purpose, 50 potential factors that may affect productivity were identified based on literature reviews and expert interviews. These factors were further explored using correlation analysis and ANOVA test. The results showed that the labor productivity is significant impacted by various project characteristics.

• Korean Journal of Construction Engineering and Management
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• v.24 no.6
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• pp.74-80
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• 2023

This study examines the characteristics of architectural review opinions as unstructured data, focusing on the most challenging risk for developers of small and medium-sized apartment projects in response to the increasing number of single-person households in Korea. Using multidimensional analysis methods, the study analyzes the review opinions of 25 projects in B City. Correspondence analysis and MDS (Multidimensional Scale) analysis show that, consistent with prior research, the keywords related to 'structure' and 'planning' dominate architectural review opinions in B City. While the MDS model's stress is very poor at 34.4%, correspondence analysis reveals that this is due to the characteristics of unstructured data in architectural reviews. In addition, the non-structured data analyzed in this study, such as architectural review opinions, exhibited a probability distribution with low kurtosis and high skewness, as they involved various combinations and occurrences of data depending on the discretion of the review committee members and the specific formats of different local governments. This often led to the emergence of keywords that differed significantly from commonly mentioned terms. Although the study has some limitations, it provides a foundation for future detailed analysis by identifying the characteristics of architectural review opinions as unstructured data.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.418-418
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• 2022

본 연구에서는 수문학적 물수지 분석을 통한 물수요-공급 시계열 분석을 수행하여 빗물이용률을 산정하였다. 물수지 분석 도구를 개발하였으며, 이를 통해 빗물이용시설 공급충족률(필요수량 대비 빗물이용량), 빗물보장률(전체일수 대비 빗물이용일수), 빗물이용률(빗물이용시서용량 대비 빗물이용가능량)에 대해 분석을 수행하였다. 업무시설, 학교, 체육시설(공원), 공동주택에 대해 수요처별 수요 시나리오를 작성하였으며, 고수요 75%, 중수요 50%, 저수요 25%를 적용하였다. 시나리오별 실제 용량과 기준용량에 따른 빗물이용률을 비교함으로써 현재 설치된 빗물이용시설이 잘 계획되었는지, 과소 계획되었는지 파악할 수 있다. 빗물이용률 분석을 위해 빗물이용시설 유형별 2개소씩 선정하였으며, 빗물이용시설 실제용량 및 기준용량(집수면적(m²)×0.05 적용)에 따른 수요 시나리오별 빗물이용률을 비교하였다. 이와 같이 물수지 분석 도구를 이용하면 다양한 시나리오 적용에 따른 운영 결과를 향후 설치될 빗물이용시설의 설치 이전에 확인하여 최적 운영방안 도출 및 저류조 용량 계획에 참고할 수 있을 것으로 판단된다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.390-395
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• 2006

Recently, construction industry demands have been changed by domestic construction circumstances such as high-technology, mega-projects, and the complexity of construction. In order to deal with the change of such a domestic construction circumstances, the Ministry of Construction and Transportation (MOCT) has introduced advanced delivery methods (i..e, CM, DB, etc.). However, the advantages and disadvantages of the advanced delivery methods have not been effectively applied for previous projects. The reason for this is that the "Reviewing Standard for the Large-scale Construction Bidding Method" has not reflected enough project characteristics when the delivery method is selected in the project planning phase. Therefore, this paper proposes the model for selecting criteria of delivery method based on project characteristics in the Multi-housing projects.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.70-79
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• 2016

The current remodeling cost estimation process is not only dependent on the historical data of new building construction, but it also has a poor linkage with risk-based estimation approach. As such, there is a high risk of falling short of initial budget. To overcome this, a risk-based estimation approach is necessary by providing a probabilistic estimation in consideration of the potential risk factors in conducting the remodeling projects. In addition, the decision-making process should be linked with the risk-based estimation results in stead of intuitive and/or experience-based estimation. This study provides a probabilistic estimation process for residential remodeling projects by developing a detailed methodology in which a step-by-step approach can be achieved. The new proposed estimation approach can help in decision-making for remodeling projects in terms of whether to proceed or not, by effectively reflecting the potential risk factors in the early stage of the project. In addition, the study can enhance the reliability of the estimation results by developing a sustainable estimation process model where a risk-based evaluation can be accomplished by setting up the cost-risk relationship database structure.

• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.207-215
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• 2007

The purpose of this study is to predict the long-term maintenance expense of BTL school projects which were ordered from the Ministry of Education and Human Resources Development and each Metropolitan and Province Office of Education. For conducting this study, the adapted research method includes a case study of BTL school projects ordered from Seoul Metropolitan Office of Education in 2006. After examination of initial investment based on each $school^{\circ}{\phi}s$ operation account, it estimates maintenance expense and long-term maintenance expense. Also it compare using two methods: one is the long-term maintenance expense estimation in apartment houses and the other is AEAM(annual equivalent amount method). The results of this study are as follows: 1) It is analyzed long-term maintenance expense rates of each BTL school. As a result, it is construction(14.0), civil(1.4%), mechanical(6.5%), equipment(6.5%), electronic(11.0%), fixture(5.1%) and the rest(1.0%). 2)It is applied using two methods: one is the long-term maintenance expense estimation in apartment houses and the other is AEAM. Finally, It is compared expense deflection per $100{\beta}{\ge}$ in each month.