• 대한건축학회논문집:계획계
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• 제35권12호
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• pp.105-114
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• 2019

The goal of this study is to quantitatively evaluate the effects of the additional construction of urban railroads. To this end, 1) establish accessibility as a measure of quantitative evaluation of construction effects; 2) select the 'Integration' of Space Syntax as a quantifiable indicator of accessibility; 3) represent the Seoul railroads as a network; 4) calculate the 'Integration' form the network before and after the additional construction of the urban railroads. By calculating the change of the 'Integration' of the individual nodes and the change of the sum of the 'Integration' of given zones, the change in accessibility of a particular node and the change in accessibility of a particular region were calculated. After analyzing the change in accessibility in nodes and areas as well, it was confirmed that the additional construction of urban railroads was improving accessibility as a whole of Seoul. It was also identified that there was a degree of difference in the extent of the accessibility change for the different areas. It is particularly noteworthy that changes occur in the accessibility ranking. While certain regions were improving relative rankings, others fell in rank. With this finding, it could be argued that active consideration of the areas in which the relative decline occurs is needed when the planned urban railroad is being built.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.244-245
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• 2021

Design VE (Value Engineering) has been basic design and implementation design separately, but due to the recent change in guidelines, it is changing to implement only once in the implementation design stage. However, in the implementation design stage, construction costs, plans, and specifications based on the volume details are almost completed. Therefore, it is effective to perform the function analysis step after identifying information analysis and key issues through CostModeling based on functional center for the selected target in the process of implementing the VE performance procedure.

• 한국조경학회지
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• 제37권1호
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• pp.28-42
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• 2009

조경공사 중 설계변경을 통하여 이루어지는 기술적 검토사안들을 토대로 설계변경의 유형분류체계를 제시하고 유형별 발생빈도와 규모, 유형간 상관성, 현장별 차이분석을 통하여 아파트단지 조경공사 설계변경의 특성을 밝히고자 하였다. 대한주택공사 충청권지역에서 2004년부터 2006년 상반기까지의 설계변경 건을 대상으로 설계변경 시 목적 및 사유로서 언급한 사안을 중심으로 유형을 구분한 결과, 단지이미지, 경관요소, 이용자 고려, 하자방지, 시공성, 현장여건, 공종간 불일치, 상위기준, 민원방지, 설계내역, 기타의 11개 유형과 47개 세부요인으로 구분하였다. 설계변경심사승인 횟수와 시기, 유형별 발생빈도와 변경규모 증감액, 상관관계를 조사 분석한 결과, 첫째, 단지이미지형 설계변경이 발생빈도 22%, 증감액 54.9%를 차지하는 주된 설계변경이었고, 둘째, 유형간 상관성 분석에서 단지이미지형 설계변경의 증가액이 커질수록 사유가 불명확한 기타 설계변경의 감소액이 커지는 반비례관계가 성립되는 등 공사비 증가를 상쇄하는 절감노력이 이루어지고 있었으며, 셋째, 설계변경심사승인 건수와 최초심사승인일은 각각 2건 이내와 준공 전 90일 이내가 $52{\sim}53%$를 차지하여 설계변경 절차가 적기에 이루어지도록 하기 위한 제도인 설계변경심사승인 자체가 사후 일괄적으로 처리되고 있었는데, 이는 공사비가 감소한 유형수와 비교결과 공사비 절감노력 즉, 예산문제에서 기인하고 있었다.

• 한국건설관리학회논문집
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• 제4권2호
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• pp.91-98
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• 2003

국내 건축설계 프로젝트에서는 협력업체간의 커뮤니케이션이 원활치 못하여 건축 부위 설계 시 성능 및 비용을 만족하는 적절한 설계대안 생성이 어려울 뿐 아니라, 설계단계에서부터 시공단견1에 이르기까지 다양한 원인으로 발생되는 설계변경에 적절히 대응하지 못하고 있다. 따라서 분야별 설계도서의 불일치로 인한 시공 품질 저하 등의 문제가 발생되고 있다. 이에 따라 본 연구에서는 건축설계단계에서 합리적인 건축설계대안 생성을 위한 협력설계 의사결정 지원시스템 구축방법의 개념을 제시하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.110-111
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• 2019

In ACI 318-19 published recently, the conditions and development length equation to use the headed deformed bars were changed considerably. Although the use of the larger-diameter(No.14 and 18) headed deformed bars isn't yet permitted, the use of the high strength(80,000psi) headed deformed bars is permitted and the effect of bar-diameter($d_b$) on the development length is increased considerably. Therefore, structures using larger-diameter headed deformed bars will be expected to be affected by this code change. We will study the effect of the code change on the development design and find out the design optimization method to minimize the effect of the changed conditions and development length equation.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.550-555
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• 2011

Utilizing construction knowledge and experiences in design phase can reduce change orders and improve productivity in construction phase. To do so, information must be made available to the design team in time. Current approaches for effective utilization of constructability knowledge, however, only focus on the formalization of constructability knowledge such as a checklist, which lacks the consideration of the appropriate use at the proper point in time. The inadequate use of constructability knowledge can result in unnecessary reworks. To deal with this problem, the design team needs to know what constructability knowledge is required for specific design activities in the design process. This paper presents a constructability implementation model using the dependency structure matrix (DSM) that focuses on information flows between design activities and constructability knowledge. For this objective, design activities in the design process are modeled in a matrix form based on their dependency. Then, constructability knowledge, which needs to be considered in the design stage, is mapped into activities and incorporated into the matrix, creating Constructability-DSM (C-DSM). Next, the partitioning algorithm is applied to C-DSM for optimal information flow. The Partitioned C-DSM is then analyzed based on the relationship between activities. Finally, the optimal utilization of construction knowledge in the design process is determined by identifying what constructability knowledge is required for each design activity, and how and when it is reflected to design for constructability. Thus, this research can help provide robust control actions to reduce unnecessary iterative cycles in design process for efficient constructability implementation.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.315-318
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• 2003

국내 건축설계 프로젝트에서는 협력업체간의 커뮤니케이션이 원활치 못하여 건축 부위 설계시 성능 및 비용을 만족하는 적절한 설계대안 생성이 어려울 뿐 아니라, 설계단계에서부터 시공단계에 이르기까지 다양한 원인으로 발생되는 설계변경에 적절히 대응하지 못하고 있다. 따라서 분야별 설계도서의 불일치로 인한 시공 품질 저하 등의 문제가 발생되고 있다. 이에 따라 본 연구에서는 건축 중간설계단계에서 합리적인 건축설계대안 생성을 위한 협력 의사결정 지원 프로세스 구축방법을 제시하였다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1283-1287
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• 2009

The Korean government implemented 259 road projects from 2004 to 2007, valued at $18.4 billion. Change orders of these road projects occurred 8,973 times and, subsequently, caused significant increases in the cost of the projects, approximately up to $4.2 billion (22.8% of the initial budget). These significant problems of huge change orders require a more workable control system for budget management whereas the effectiveness of the government's control is still not satisfied. However, previous approaches and studies mostly limited their analyses to simply classifying the causes of the change orders. This paper investigates the real frequency and cost impacts incurred by each cause of a change order, primarily based on 218 road projects in Korea. The paper then identifies the attributes of change orders through a survey of 204 project participants in that those sources were inevitable or avoided if properly managed. The causes of the change orders are further analyzed with analysis of variance (ANOVA) in connection with contract volume, bid award rate, the contractor's capacity to perform, and the design company's capacity. This study found that if the contract volume is smaller, then the possibility of change orders is higher. Interestingly, if the bid award rate is less than 67.5%, it signifies the highest rate of change orders. In addition, the contractors whose construction ability is assessed as the top-ranked group showed the lowest change order rates. With these results, this paper provides the preventive guidelines for reducing the likelihood of change orders.

• 한국건설관리학회논문집
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• 제4권4호
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• pp.106-113
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• 2003

The purpose of this thesis is to provide an appropriate trade-off information for the conflicting interests caused by the various factors between building owner and contractor during selecting the contractor and performing the construction work, in which the construction was contracted by open bidding from the government or private organizations. In order to propose the legitimate evidence, the differences between the domestic contract sheet of drawing change and the process of drawing change and those of the foreign countries were compared and analysed The number of construction ordered in Youngdong area in 2001 whose construction expenses are more than 100,000,000 won is 218 items and 147,005,000,000 won in total cost Among them, the number of 218 items whose total cost amounts to 16,705,000,000 (11.36$\%$) is in case of increase of construction expenses due to the drawing changes, and the number of 48 items whose tool cost amounts to 2,009,000,000 won (1.37$\%$) is the case of decrease. In conclusions, the contractor could have more benefits than the building owner in case they submit the detailed estimate sheet without eliminating the increasing expenses of construction. It is shown that the building owner's loss is increasing whenever the labor cost is higher material cost Therefore, this thesis proposes a proper standards for the harmonious compromise between the contractor and the building owner for the problems caused by the drawing changes when the contract agreement is occurred.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.48-49
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• 2020

Recently the diversification of construction market and the continuous reduction of construction amount are raising the need of alternative delivery method in the construction industry. The foreign advanced companies actively adopted the CM at Risk delivery method where they perform the service of agent CM in the design phase, and agree GMP(Guaranteed Maximum Price) with the client at the time of 50~80% completion of design. Even in Korea they began to apply that method to pilot projects. In CM at Risk, through the early participation of builder, the level of design completion can be improved and the change order and construction period delay can be minimized. On the other hand, GMP is usually calculated when the design is about 80% complete, so there is uncertainty in the construction cost. Therefore, in this research, the increased amounts of construction cost are analyzed in a number of public construction projects, and GMP calculation process is proposed using the analysis results and CBR(Case-Based Reasoning) technique to reduce the construction cost increase in the construction phase.