• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.558-561
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• 2006

In many case, reinforced concrete structures are deteriorated by construction errors, design errors, settlement and movement, and weathering. The diagnose and repair of concrete deterioration is important for effective management of concrete structures. This manual is to provides guideline on evaluating the deterioration of the concrete in a structure and selecting an appropriate repair material and method.

• Journal of applied mathematics & informatics
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• 제16권1_2호
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• pp.143-150
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• 2004

In this paper we study the estimation problem of individual weights of objects using an A-optimal chemical balance weighing design. We assume that in this model errors are correlated and they have the same variances. The lower bound of tr$(X'G^{-1}X)^{-1}$ is obtained and a necessary and sufficient condition for this lower bound to be attained is given. There is given new construction method of A-optimal chemical balance weighing design.

• 한국건설관리학회논문집
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• 제7권5호
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• pp.177-190
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• 2006

Construction projects are facing delay problems. Delays in construction have been immense effect on performance or satisfactory delivery of the project. Delays have been causing project cost overrun as well as it is a source of dispute hence damaging the relationship between the project participants. The purpose of this study was to explore the causes of delay risk through a field survey study. Data were collected from construction professionals working in owner, consultant and contractor organizations. All together 208 questionnaire instruments were used and analyzed by employing statistical tools (SPSS computer program). 19 delay factors were identified by this study, out of which following factors were critical: Frequent interruptions from public (local people, pressure group etc.), changed site condition, failure to provide required construction site, unrealistic project time estimation and design errors.

• The Journal of Asian Finance, Economics and Business
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• 제9권4호
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• pp.307-314
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• 2022

The construction and real estate industries contribute significantly to each country's economic development. Strong construction and real estate firms will contribute more to the country's GDP by contributing to the industry's development. The purpose of this study is to examine the factors that influence the performance of the construction and real estate sectors in Vietnam. A survey of 200 construction and real estate firms in different areas was conducted from 2020 until the end of 2021. Following the removal of errors, the author got 196 replies, 6 of which were invalid, leaving 190 votes for quantitative analysis. The research findings show that elements such as (1) senior executives' commitment to the organization, and (2) the ability to use technology have a positive and significant impact on firm performance when using advanced econometric analysis. Furthermore, in the case of Hanoi, Vietnam, business relationships have a positive impact on firm performance. Training and development, as well as the working environment and incentives, have little effect on the profitability of construction and real estate firms. Finally, the research also has some recommendations and limitations for the construction and real estate sector.

• 한국건축시공학회지
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• 제23권4호
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• pp.485-496
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• 2023

Precise construction cost estimation is paramount to determining the total construction expense of a project prior to the initiation of the construction phase. Despite this, manual quantification and cost estimation methods, which continue to be widely used, may result in imprecise estimation and subsequent financial loss. Given the fast-paced and efficiency-demanding nature of the construction industry, trustworthy quantity and cost estimation is essential. To mitigate these obstacles, this research is focused on establishing an automated quantity estimation algorithm, particularly designed for the main rebar of beams which are recognized for their complicated reinforcement configurations. The exact quantity derived from the proposed algorithm is compared to the manually approximated quantity, reflecting a variance of 10.27%. As a result, significant errors and impending financial loss can be averted. The implementation of the findings from this research holds the potential to significantly assist construction firms in quickly and accurately estimating rebar quantities while adhering strictly to applicable specifications and regulatory requirements.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.573-577
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• 2015

Safety is paramount for construction industry throughout the world. Human errors which contribute to more than half of construction accidents, could be proactively prevented through effective education and training methods. Although Virtual Reality (VR) and Augmented Reality (AR) have gained much attention in various disciplines, few studies applied them for construction safety education. This research presents a new approach in construction safety education by utilizing VR and AR. The vision of aligning teaching & learning strategies is examined in order to ensure the potential benefits of the new method. This innovative approach shifts safety education from "Listen, and I will forget. See, and I may remember" towards "Practice, and I understand".

• 한국주거학회논문집
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• 제27권6호
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• pp.137-144
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• 2016

In modular architecture, manufacturing drawing which includes whole information for modular unit production is essential since works for modular unit have to be performed in manufacturing factory not construction field. Although the manufacturing drawing is important as known it is insufficient to utilize the manufacturing drawing in modular architecture project and this makes modular unit low-quality with re-work and work time delay. To prevent low-quality modular unit caused by insufficient manufacturing drawing, in this research firstly manufacturing drawing's current situation and error cases in manufacturing phase of past modular housing project were analyzed, and correlation between reduction of errors occurance frequency and improving manufacturing drawing was verified. Secondly manufacturing drawing improvement factors were deducted in interior, furniture, mechanical work phase which errors' occurance rate is high and the way of deducting manufacturing drawing lists and contents were suggested with light-weight work as an example in case of new type of errors occurance. A series of research process can contribute to good-quality modular unit by errors reduction. As a result of research, about half of errors occurance can be reduced with suggested manufacturing drawing improvement factors. And the manufacturing drawing process can contribute to modular production which have uniform quality.

• 대한의용생체공학회:의공학회지
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• 제30권1호
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• pp.10-17
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• 2009

Accurate electroencephalography (EEG) forward calculation is of importance for the accurate estimation of neuronal electrical sources. Conventional studies concerning the EEG forward problems have investigated various factors influencing the forward solution accuracy, e.g. tissue conductivity values in head compartments, anisotropic conductivity distribution of a head model, tessellation patterns of boundary element models, the number of elements used for boundary/finite element method (BEM/FEM), and so on. In the present paper, we investigated the influence of modeling errors in the boundary element volume conductor models upon the accuracy of the EEG forward solutions. From our simulation results, we could confirm that accurate construction of boundary element models is one of the key factors in obtaining accurate EEG forward solutions from BEM. Among three boundaries (scalp, outer skull, and inner skull boundary), the solution errors originated from the modeling error in the scalp boundary were most significant. We found that the nonuniform error distribution on the scalp surface is closely related to the electrode configuration and the error distributions on the outer and inner skull boundaries have statistically meaningful similarity to the curvature distributions of the boundary surfaces. Our simulation results also demonstrated that the accumulation of small modeling errors could lead to considerable errors in the EEG source localization. It is expected that our finding can be a useful reference in generating boundary element head models.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.425-428
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• 2015

New technologies using a CNC machine are being developed to reduce the production cost of free-form buildings. For production of free-form members using such technologies, vast free-form buildings should be first split into multiple panels that are productible. Taking into consideration of the curved surface of free-form members, the segmented free-form panels may vary in shape and size, which may cause a lot of errors. In addition, it is time-consuming for the work. However, the current panelizing work is completed with the trials and errors of engineers and architectural designers even in large-scale projects, which results in increased construction duration and cost. Thus, it is necessary to develop a technology for panelizing free-form panels so as to maximize the economic feasibility of production technologies for free-form concrete members. The study intends to develeop automatic panelizing algorithms of free-form buildings considering the curved surface and size of free-form panels and the production conditions. The developed algorithms will be useful in applying the production technologies of free-form buildings using CNC machine and reducing the cost.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.39-40
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• 2018

The goal of site layout planning(SLP) is to maximize the productivity and efficiency of the construction by reducing travel distance and material handling cost and manpower. However, SLPs are static layout schemes, which cannot be reorganized during the construction process to correspond with errors, phase transition, changing working environments on the site. To solve this problem, researches on dynamic site layout planning(DSLP) are emerging. This preliminary study clarifies characteristics of temporary facility's variables to develop the vertical DSLP algorithm of high-rise building construction.