• Journal of Construction Engineering and Project Management
• /
• 제5권4호
• /
• pp.7-11
• /
• 2015

The luffing-tower crane (T/C) is a key facility used in the vertical and horizontal transportation of materials in a tall building construction. Locating the crane in an optimal position is an essential task in the initial stages of construction planning. This paper proposes a new optimization model to locate the luffing T/C in the optimal position to minimize the transportation time. A newly developed mathematical formula is suggested to calculate the transportation time of luffing T/C correctly. An optimization algorithm, the Harmony Search (HS) algorithm, was used and the results show that HS has high performance characteristics to solve the optimization problem in a short period of time. In a case study, the proposed model offered a better position for T/C than the previous heuristic approach.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.573-578
• /
• 2009

Previous research on super high rise buildings focused mostly on the use of public space from building plan perspective, survey of residents' satisfaction evaluation, construction technology and structural technology. But little research is done on the economic analysis of landmark factors. The purpose of this study is to find landmark factors that can be quantitatively measured, collect data on super high rise residential buildings in Seoul. Find the intrinsic values of the landmarks, and analyze how these values differ in areas with different densities, i.e. in 3 Gangnam-gus & Yeongdeungpo-gu and in other areas. It is expected that the results of this study can be used to set an appropriate price of super high rise building in consideration of its landmark value in different area

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.420-424
• /
• 2015

The luffing-tower crane (T/C) is a key facility used in the vertical and horizontal transportation of materials in a tall building construction. Locating the crane in an optimal position is an essential task in the initial stages of construction planning. This paper proposes a new optimization model to locate the luffing T/C in the optimal position to minimize the transportation time. An optimization algorithm, the Harmony Search (HS) algorithm, was used and the results show that HS has high performance characteristics to solve the optimization problem in a short period of time. In a case study, the proposed model offered a better position for T/C than the previous heuristic approach.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.702-703
• /
• 2015

Currently, according to the climate change, serious damage by Typhoon has been occurred in the world. In this respect, the research on the damage prediction model to minimize the damage from various natural disaster has been conducted in several developed countries. In the case of U.S, various damage prediction models of buildings from natural disasters have been used widely in many organizations such as insurance companies and governments. In South Korea, although studies regarding damage prediction model of hurricane have been conducted, the scope has been only limited to consider the property of hurricane. However, it is necessary to consider various factors such as socio-economic, physical, geographical, and built environmental factors to predict the damages. Therefore, to address this issue, correlation analysis is conducted between various variables based on the data of hurricane from 2003 to 2012. The findings of this study can be utilized to develop for predicting the damage of hurricane on buildings.

• 기호학연구
• /
• 제54호
• /
• pp.205-224
• /
• 2018

본 연구는 건축기호학에서 퍼스 기호학의 논리적 장점을 건축 디자인에 활용하기 위해 필요한 연구의 일환으로서 퍼스 유형론의 적용성을 검토하고 건축 디자인에 접목하기 위한 방법을 모색하는 연구이다. 이를 위하여 형식논리학 관점에서 양자의 접목 방법에 대하여 검토한다. 나아가서 본 연구에서는 기호포함구조가 기호 성장 모델의 근간 역할을 할 수 있는 가능성에 대해서 검토한다. 본 연구에서는 퍼스의 기호 유형론의 역삼각형 구조를 재구성한 기호포함구조의 도식을 제시하고 이것을 중심으로 논의를 진행하였다. 연구 결과 건축 디자인에서 이루어지는 해석, 생성 작업의 연속성과 논리성이 본 연구에서 제시된 기호포함구조의 삼중 구조를 적용함으로써 논리적, 구조적 설명과 분해가 가능하고 이를 통해 디자인의 질 향상에 기여할 수 있다는 것이 나타났다. 나아가서 제시된 기호포함구조는 건축 디자인에서 이루어지는 기호의 확장 또는 성장 모델의 배경 프레임 역할을 할 수 있다는 가능성이 나타났다. 향후 적용성을 높이기 위한 과제로서 건축 디자인 사고와 기호 유형론에 근간한 포함 관계적 사고를 추론 프레임으로 결합하기 위한 연구의 필요성이 나타났다.

• 한국건축시공학회지
• /
• 제13권4호
• /
• pp.416-423
• /
• 2013

An adjusted assessment model based on benefit-cost analysis (BCA) is proposed for evaluating the economic efficiency of automated construction technologies. In contrast to conventional BCA, the model does not compare monetary values, but the differences in benefits and costs between traditional and automated construction methods. To verify the usefulness of the model, it was applied to a real-scale building construction project that used a fully automated building construction system, and the face validity of the model was confirmed. The results indicate that the model can support decision makers in identifying valuable benefit factors and in assessing the cost effectiveness of the system.

• Journal of Construction Engineering and Project Management
• /
• 제1권3호
• /
• pp.28-37
• /
• 2011

Domestic construction companies are suffering from financing difficulties in the wake of the economic slump in Korea and abroad. During this economic slump, real estate investment trusts (REITs), facilitators for improving financing and stimulating construction businesses, have increasingly expanded since their introduction in 2001. However, in terms of growth speed and marketing size, Korean REITs are falling behind those of other nations. The purpose of this study is to suggest a method for composing a portfolio using the Markowitz portfolio selection model to stimulate REITs. The main contents are as follows. First, a comparative analysis was conducted of increased REIT profit with the application of the Markowitz model and the average REIT profit rate from July 3, 2007, to July 21, 2008, during the investment analysis periods. The results showed that the total profit rate from the Markowitz model was about 10% higher than the average REIT profit rate. Second, the sensitivity was analyzed according to the portfolio's data-gathering and replacement cycle to measure the optimum cycle and yield. The six-mouth profit data collection period showed about 16% higher profits with the Markowitz model than with the REITs. The two-week portfolio change period resulted in about 11% higher profits with the Markowitz model than with the REITs.

• Geomechanics and Engineering
• /
• 제38권5호
• /
• pp.507-515
• /
• 2024

An accurate estimation of the geotechnical parameters in front of tunnel faces is crucial for the safe construction of underground infrastructure using tunnel boring machines (TBMs). This study was aimed at developing a data-driven model for predicting the rock quality designation (RQD) of the ground formation ahead of tunnel faces. The dataset used for the machine learning (ML) model comprises seven geological and mechanical features and 564 RQD values, obtained from an earth pressure balance (EPB) shield TBM tunneling project beneath the Han River in the Republic of Korea. Four ML algorithms were employed in developing the RQD prediction model: k-nearest neighbor (KNN), support vector regression (SVR), random forest (RF), and extreme gradient boosting (XGB). The grid search and five-fold cross-validation techniques were applied to optimize the prediction performance of the developed model by identifying the optimal hyperparameter combinations. The prediction results revealed that the RF algorithm-based model exhibited superior performance, achieving a root mean square error of 7.38% and coefficient of determination of 0.81. In addition, the Shapley additive explanations (SHAP) approach was adopted to determine the most relevant features, thereby enhancing the interpretability and reliability of the developed model with the RF algorithm. It was concluded that the developed model can successfully predict the RQD of the ground formation ahead of tunnel faces, contributing to safe and efficient tunnel excavation.

• Computers and Concrete
• /
• 제34권4호
• /
• pp.503-517
• /
• 2024

This study presents an analysis model to estimate the shear strength of a reinforced concrete (RC) member with corroded tensile reinforcements. The thick-walled cylinder theory was modified to fit the dual potential capacity model to reflect interdependent failure mechanisms, including the degradation effect of bonds in corroded tensile reinforcement. In the proposed model, it is considered that the shear failure of corroded RC members with no proper anchorage detail is primarily dominated by the flexural-bond mechanism, where insufficient bond strength is provided owing to corrosion damage. However, when tensile reinforcements are properly anchored in the end regions using end hooks or mechanical devices, it is assumed that the tied-arch action can be developed as a secondary shear transfer mechanism, even under severe corrosion damage. The proposed model was verified by comparison with shear test results of corroded RC members collected from the literature, and it appeared that the proposed model can estimate their shear strengths with a good level of accuracy, regardless of various anchorage details and corrosion rates in tensile reinforcements.

• 건축역사연구
• /
• 제5권2호
• /
• pp.83-95
• /
• 1996

Computerized visual database construction of architectural precedents has just begun in some research institutes in the world. In Korea the first visual database has shown its testl version by S architectural design firm in september 1996. In this article the author discusses the historical contexts and the recent computerization cases, the traits, the uses and the limits of architectural visual database system of precedents. The forms and contents of data fields in two cases are compared with a focus on the description of architectural traits of each data entry. Compared to the KIA format, the S database has better performance for architectural design reference because it collects more pictures and drawings and larger texts for the field of architectural chracteristics. But this latter also is constrained by its capacity of memory and so lacks the reciprocity of the DOORS in the Graduate School of Design, Harvard University. A visual database system which has more flexible allocation of memory and respondent with the users is yet to be prepared. But this system also should be maintained by some experts in architectural history, theory and criticism, because their knowledge is essential for selection of precedents and revision of the data description. A full-fledged electronic visual database in architecture will not only save much effort for the architect, but also will change the architects' design behavior. Nevertheless this does not mean the automatic promotion of architects' creativity.