• Advances in concrete construction
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• 제10권6호
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• pp.527-536
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• 2020

In this study, a process is proposed to calculate analytical correction values for the vertical shortening of all columns on all floors in a high-rise building that minimizes the error between the structural analysis predictions and values measured during construction. The weight ratio and the most probable value were accordingly considered based on the properties of the shortening value analyzed at several points in each construction stage and the distance between these measured points and unmeasured points at which the shortening was predicted. The effective range and shortening value normalization were considered using the column grouping concept. These tools were applied to calculate the error ratio between the predicted and measured values on a floor where a measured point exists, and then determine the estimated error ratio and estimated error value for the unmeasured point using this error ratio. At points on a floor where no measured point exists, the estimated error ratio and the estimated error value were calculated by applying the most probable value considering the weight ratio for the nearest floor where measured points exist. In this manner, the error values and estimated error values can be determined at all points in a structure. Then, the analytical correction value, defined as this error or estimated error value, was applied by adding it to the predicted value. Finally, the adequacy of the proposed correction method was verified against measurements by applying the analytical corrections to all unmeasured points based on the points where the measurement exists.

• 한국건축시공학회지
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• 제6권4호
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• pp.77-83
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• 2006

The purpose of this study is to measure the straightness of prefounded columns during underground construction stages. There are several causes of an error of prefounded column: (1) columns connected by welding or bolting, (2) by placement of concrete and aggregates around columns, (3) movement during construction, and (4) load applied during construction. The error of column straightness is different for each column, and the tilting of columns is shown in one or two directions between floors. The additional loads caused by the error of straightness may give damage to buildings. This paper presents the measurement results of column straightness, and thus providing a basis for further analysis.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.67-73
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• 2022

Construction bid documents contain various errors or discrepancies giving rise to uncertainties. The errors/discrepancies/ambiguities in the bid document, if not identified and clarified before the bid, may cause dispute and conflict between the contracting parties. Given the fact that bid document is a major resource in estimating construction costs, inaccurate information in bid document can result in over/under estimating. Thus, any questions from bidders related to the errors in the bid document should be clarified by employers before bid submission. This study aims to examine the pre-bid queries, i.e., pre-bid request for information (RFI), from state DoTs of the United States to investigate error types most frequently encountered in bid documents. For the study, around 200 pre-bids RFI were collected from state DoTs and were classified into several error types (e.g., coordination error, errors in drawings). The analysis of the data showed that errors in bill of quantities is the most frequent error in the bid documents followed by errors in drawing. The study findings addressed uncertainty types in construction bid documents that should be checked during a bid process, and, in a broader sense, it will contribute to advancing the construction management body of knowledge by clarifying and classifying bid risk factors at an early stage of construction projects.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제2권2호
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• pp.82-102
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• 2008

Packet losses tend to occur during short error bursts separated by long periods of relatively error-free transmission. There is also a significant spatial correlation in loss among the receiver nodes in a multicast session. To recover packet transmission errors at the transport layer, tree-based protocols construct a logical tree for error recovery before data transmission is started. The current tree construction scheme does not scale well because it overloads the sender node. We propose a scalable recovery tree construction scheme considering these properties. Unlike the existing tree construction schemes, our scheme distributes some tasks normally handled by the sender node to specific nodes acting as repair node distributors. It also allows receiver nodes to adaptively re-select their repair node when they experience unacceptable error recovery delay. Simulation results show that our scheme constructs the logical tree with reduced message and time overhead. Our analysis also indicates that it provides fast error recovery, since it can reduce the number of additional retransmissions from its upstream repair nodes or sender node.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.31-32
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• 2023

Recently, with the digitalization of the construction industry, free-form building construction technology is developing. However, the technology for manufacturing free-form concrete panels is still insufficient. In this study, the surface error of the FCP according to the thickness of the lower silicon plate, which is a component of the existing lower multi-point press, was analyzed in order to manufacture a precise FCP. As a result of the analysis, it was found that the thinner the thickness, the larger the error value. These results can be used as a basis for existing research and are expected to be used for research on high-quality FCP manufacturing technology.

• 한국건설관리학회논문집
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• 제16권2호
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• pp.77-85
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• 2015

현재 건설공사 사후평가시스템 입력과정에서 자료가 오류 및 누락이 발생되는 경우가 많아 데이터의 신뢰성이 떨어지는 경우가 많다. 이에 따라 본 연구에서는 사후평가 결과분석의 신뢰성 확보를 위해 건설공사 사후평가시스템의 입력누락 및 입력오류에 대한 세부적인 분석을 실시하였다. 분석결과, 건설사업 초기 단계일수록 자료의 미입력된 자료의 비중이 높게 나타났다. 그리고 분석된 등록오류로는 참고자료의 부정확, "원" 단위 오류, 입력항목에 대한 이해부족 등으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.108-109
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• 2019

Top-down construction is a useful method of utilizing the working space, economic benefits and shorten the construction period. Precision construction of the elevator core is very important for safety of the top-down structure. In this study, the layout system for the field-BIM(Building Information Modeling) was used to precisely construct the elevator core in the basement and the ground. Through the layout system, it was possible to process the construction status, review the design results and construction errors, and confirm whether there is or not within the construction error range for elevator installation.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1042-1047
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• 2005

A web-based camera (webcam) is expected to enhance construction operation monitoring. However, webcams are often installed outside a building because their mobility is limited by cable wiring, which makes it difficult to monitor construction operations inside the building. If a webcam is integrated with emerging wireless communication technologies, construction professionals may be able to monitor interior construction operations using webcams without getting network cables wired on a congested and dynamic construction job site. However, one may concern that wireless communication may not be fast enough to transport all webcam images seamlessly. This paper presents an investigation as to the observation error of webcam images when a limited amount of images are delivered.

• 한국재난정보학회 논문집
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• 제17권1호
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• pp.154-164
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• 2021

연구목적: 건설업 기초안전보건교육이 실시된 지 10년이 지난 지금 더 이상의 보수교육이 실시되지 않고 있으며, 기초안전보건교육을 이수한 사람은 신규채용자교육도 면제되고 있어서 안전교육이 부실화되고 있다. 조속히 보수교육과 신규채용자교육의 법제화로 불안전한 행동의 유발을 방지하고 안전사고를 방지하기 위한 전략적 방안을 모색하고자 한다. 연구방법: 본 연구에서는 건설안전교육인 기초안전보건교육과 신규채용자교육이 불안전한 행동인 Human Error와 위반 행동과의 구조적 관계를 설문을 통한 회기분석을 실시하였다. 연구결과: 설문조사는 건설업 기초안전보건교육과 신규채용자 교육이 재해의 인적 요소인 Human Error와 위반 행동 감소에 많은 영향이 있는 것으로 분석되었고 지속적인 안전교육이 안전의식을 높일 수 있음을 확인하였다. 결론: 기초안전보건교육의 보수교육과 신규채용자 교육의 법 개정으로 안전교육의 부실화를 방지하여야 한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.140-141
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• 2015

Although the depression of oversea construction market becomes more serious recent years, asian construction market is relatively dynamic, particularly in china. However, few research has been conducted about how to manage construction projects in china as foreign developers. Four important risks are identified from series of surveys using the WBS-RBS method, the result shows that the main risk of tender stage is 'Tender max price error', ' Bill of quantities error', 'Unusual low price' and 'Moral risk' respectively.