• 산업공학
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• 제12권3호
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• pp.395-400
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• 1999

Shipbuilding process is composed of hull construction, in which the structural body of a ship is formed, and outfitting, in which all the non-structural parts such as pipes, derricks, engines, machinery, electrical cable, etc. are manufactured, added and assembled. Hull construction can be classified into parts fabrication, block assembly and hull erection. Among them, the parts fabrication is the first manufacturing stage that produces components or zones needed for block assembly and hull construction. More specifically, the parts fabrication is performed through machining processes including marking, cutting, pressing, and/or forming. When material is entering into the parts fabrication stage, it is important for achieving the total efficiency of production to select one of production division, so-called 'bay,' as well as machine tools on which the part is fabricated. In this paper, given production quantities of parts in the fabrication stage, the problem is to optimally select machine tools and production division, such that the total flow-time is minimized as well as the workload among machines is balanced. Specifically, three mathematical models for flow-time minimization, load balance, and simultaneously considering both objectives, and a numerical example are analyzed and presented.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.223-224
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• 2021

The process before the model learning stage in AI R&D can be subdivided into data collection/cleansing-data purification-data labeling. After that, according to the purpose of development, it goes through a stage of verifying the model by performing learning by using the algorithm of the artificial intelligence model. Several studies describe an important part of AI research as the learning stage, and try to increase the accuracy by changing the structure and layer of the AI model. However, if the refinement and labeling process of the learning data is tailored only to the model format and is not made for the purpose of development, the desired AI model cannot be obtained. The latest research reveals that most AI research failures are the failure of the learning data rather than the structure of the AI model. analyzed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.214-215
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• 2022

This study analyzed the development stage and change management necessity of the construction IT system through existing research and literature review, and used WordCloud, one of the text mining techniques, to analyze current construction trends and major issues. The necessity of change management is derived by using existing research literature and construction-related social issues as analysis data.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.95-96
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• 2023

The purpose of this study is to derive the limitations of the existing management system by analyzing the characteristics of the PC process to improve the PC construction project management system process. To overcome the limitations derived, we present a process of managing integrated information from the design-production-construction stage using QR codes and clouds. This is expected to help develop a PC construction project management system.

• 한국건설관리학회논문집
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• 제7권4호
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• pp.91-99
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• 2006

본 연구는 신축 교육시설 프로젝트의 개념단계에서 공사비를 예측하기 위한 인공신경망모델의 제안을 목적으로 한다. 현행 공공 교육시설의 개념단계 공사비예측에는 기본인자인 연면적에 의한 단일변수 모델이 적용되고 있다. 그러나 개념단계에서 단일변수 공사비예측모델을 적용하여 예측된 공사비는 그 오차범위가 크고, 실시설계 완료 후 물량산출에 의해 산정된 상세공사비와 비교하여 큰 차이를 보일 경우 프로젝트의 수정이 불가피하며, 이는 프로젝트의 비용을 증가시키고 공기를 지연시킨다. 그러므로 본 연구에서는 교육시설 프로젝트의 사업계획 수립 및 예산확보 과정에서 공사비예측에 적용이 가능한다 변수 인공신경망모델을 제안하였다. 개발된 모델을 평가한 결과 평균오차율이 6.82%로써, 평균 93.18%의 정확도를 기록하였다. 제안된 인공신경망모델은 지난 5년간 신축된 교육시설의 공사예정금액을 실적자료로 사용하여 학습되었기 때문에, 차후 교육시설 신축공사의 예산편성에 그 활용이 기대된다.

• 산업경영시스템학회지
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• 제46권3호
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• pp.209-220
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• 2023

Recently, defects that occurred during the construction of apartment houses have become a social issue. Defects in apartment houses lead to waste of resources and economic loss, causing psychological and physical damage to customers, and a decrease in reliability and financial loss to construction companies. The purpose of this study was to analyze the impact of defect occurrence according to the difference in project management level in the apartment housing construction stage, and to investigate the extent to which the project manager's experience affects the defect occurrence rate. For the empirical analysis of the study, statistical analysis was conducted using data collected from 130 actual projects. The results of the analysis showed that schedule management, cost management, and quality management had a positive effect on reducing the defect occurrence rate in the execution stage of apartment housing construction, while human resource management productivity had a negative effect. This study theoretically demonstrated the importance of project management, and in practice, showed that schedule management, cost management, and quality management should be faithfully performed in the execution stage to reduce the rate of defects after project completion. It was also suggested that hiring an experienced project manager would help reduce project defects.

• 한국물환경학회지
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• 제18권2호
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• pp.141-150
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• 2002

Two-stage membrane bioreactor using submerged hollow fiber membrane was applied in laboratory scale to treat nitrogen and phosphorus of domestic wastewater. Alum as the flocculant and adsorbent was added into the anaerobic basin of two-stage membrane bioreactor and mixed liquid of aerabic basin was recycled to the anaerobic basin for the purpose of nitrogen removal. Experiment was carried out to find removal efficient of phosphorous and nitrogen components in the mixed liquid, and the stability of the permeate flux and pressure of two-stage membrane bioreactor. In case of alum was added as the flocculant and adsorbent into the anaerobic basin, soluble phosphorus removal efficient was relatively higher and total permeate resistance(Rtot) was more increased out nitrogen removal efficient was lower as the result of lack of alkalinity and insufficient nitrification process than the case of alum was not added.

• 한국강구조학회 논문집
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• 제23권1호
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• pp.99-111
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• 2011

본 연구에서는 비선형 해석을 통하여 폐합 전 강사장교의 주요한 좌굴 거동 특성을 고찰한다. 케이블의 새그효과, 주탑과 거더의 P-${\Delta}$ 효과, 구조물의 대변위효과 등의 주요한 기하학적 비선형성을 모두 고려하기 위해 기하학적 비선형 해석으로써 구조물의 좌굴 해석을 수행하였다. 초기형상 해석 및 시공단계 해석을 통해 사하중을 받고 있는 시공 단계에 있는 구조물의 해석을 수행하였고 이 후 데릭 크레인과 키 세그먼트의 자중에 대한 비선형 해석으로 폐합 전 사장교의 좌굴 해석을 수행하였다. 본 해석 연구에서는 케이블의 배치 형태 및 주탑과 거더간 강성비에 따른 좌굴 모드 및 임계 하중계수의 변화를 분석하였다. 연구 결과 주요한 좌굴 모드를 구분하고 케이블 배치 형식이 다른 각 사장교에서 각 좌굴 모드가 나타나는 주탑과 거더간 강성비의 범위를 도출하였다.

• 한국안전학회지
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• 제28권5호
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• pp.35-40
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• 2013

Recently reclamation land is largely developed to utilize the land according to economic growth. The soil of landfill is soft, low shear strength, which makes it difficult to use the equipment. A large movement is occurred on the utility tunnel under construction. The inclined land with high water level and underground facilities are widely distributed and the excess pore water pressure may occur under construction similarly to this study. Some different conditions are made to design result, such as 4m of soil piling near the construction area, heavy rainfall during 2nd excavation that may cause flow liquefaction. To analyze the cause of transverse lateral movement, Three dimensional analysis are performed to four load cases, which is original design condition, flow liquefaction by heavy rainfall, unsymmetric lateral soil pressure, and both of them simultaneously. Ten steps of full construction stage, 1st excavation for utility tunnel, construction of utility tunnel, 1st refill, piling soil from 1m to 4 m, 2nd excavation for drainage culvert, liquefaction around the utility tunnel, construction of drainage culvert and 2nd refill, are take into account to investigate the cause of movement.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.53-54
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• 2012

This study is aimed at utilizing LCA processor with BIM LOD, eliciting the problems of the existing environmental assessment by constructing the database for environmental values of green buildings. For these objects, environmental load database of BIM construction material and evaluation process are presented, after matching BIM family based environmental load database which is available during evaluation stage, input-output tables and Korea LCI database to standard item code of public procurement service. It is a important factor in environmental assessment of building to develop database unit of standard item code for BIM and construction material. Thus, the results of this study are expected to provide basic data for improving effectiveness of construction through BIM based environmental load evaluation database. Furthermore, the provided environmental load database unit for construction material is considered to be available as basic information for BIM study by suggesting a processor connecting BIM with LCA and along with this, continuous examination on the connection process is needed.