• Korean Journal of Construction Engineering and Management
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• v.19 no.1
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• pp.43-53
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• 2018

Modular construction can improve construction quality and accuracy through manufacturing process, and it allow massive production and cost savings by repeatedly producing the same unit. In particular, it is possible to reduce the time because the on-site work and the manufacturing process can be carried out at simultaneously. However, according to the modular construction project survey report, there is no significant difference regarding the average construction period between modular construction and conventional construction. This is due to schedule delay problems that occur during construction phase. Therefore, it is necessary to select alternatives to prevent schedule delay during on-site construction progressing. Especially, in case of large-scale modular construction project, on-site module assembly and manufacturing process are performed concurrently. Hence, identification of alternatives should be done at the co-occurrence by taking both manufacturing and on-site work process in to account. In this research, the management factors of large-scale modular construction project were identified through the IDEF0 modeling, and the quantity management model for manufacturing and assembly is developed. This will reduce the schedule delay problem that occurs in the progression on-site work of a large scale modular construction.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.2
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• pp.97-102
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• 2009

In this paper, the problem of stability analysis for networked control systems with norm-bounded parameter uncertainties is investigated. By construction Lyapunov's functional, a new delay-dependent stability criterion for uncertain networked control system is established in terms of LMIs (linear matrix inequalities) which can be easily by various convex optimization algorithms. One numerical example is included to show the effectiveness of proposed criterion.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.87.5-87
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• 2001

In the past, we presented the tracking system with one sampling delay. In this paper, first we propose a tracking system with N-th sampling delay, in the case where an input-output pulse transfer function of a plant Z$\_$-N/. Secondly we propose a system configuration converting an input-output pulse transfer function of a plant into Z$\_$-N/ with the inverse system of the plant. Moreover, the proposed tracking system configuration is applied to an actual Ball and Beam system and good results are obtained.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.217-221
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• 2003

This study proposes a new classification system and analysis methodology for time delay risk of apartment projects. And this study proposes the classification of major trades and risk level and risk index by performing expert-oriented interview and survey report on a national scale. The purpose of this study is to present basic data for time delay risk management system through the analysis of risk level, risk index and rank of major 5 trades(earth work, structure work, masonry work, window and door/glass work, and interior finish work) in apartment projects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1037-1043
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• 2006

This work presents an effective overlay multicast tree construction algorithm for synchronized real-time media multicast service over the Internet. The proposed algorithm is designed to minimize delay variance among group members to provide the synchronized service as well as average delay of group members in order to support the service in real-time. Basically, of orthogonal genetic algorithm is employed to obtain the near optimal tree with a low computational complexity since the given problem is NP-complete. Finally, experimental results are provided to show the superior performance of the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.305-313
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• 2011

This paper presents a P2P (Peer-to-Peer) overlay multicast tree construction algorithm to support stable multimedia service over the Internet. While constructing a multicast tree, it takes into account not only the link delay, but also peer stability. Since peers actually show dynamic and unstable behavior over P2P-based network, it is essential to consider peer stability. Furthermore, the weighting factor between link delay and peer stability is adaptively controlled according to the characteristics of the multicast tree. Basically, Genetic algorithm is employed to obtain a near optimal solution with low computational complexity. Finally, simulation results are provided to show the performance of the proposed algorithm.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.250-255
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• 2004

To analyze delay, Seoul - Daegu line of Korea High Speed Railway was divided into three sections and analyzed independently by the business characteristics. The analysis on the project delay reasons was performed on macro and micro scales. This analytic method was named as 'Macro-Micro Delay Analysis Method (MMDAM)'. The macro scale analysis has three approaches, which are (1) scheduling, (3) structural characteristic, (3) and responsibility of project administrative works. Micro analysis also has three, methodologies which are (1) As Planned Method, (2) As Built method, (3) Modified Time Impact Analysis for analyzing the most influential section which the largest delay occurred. Using elicited project delay reasons from above analysis, the questionnaire was carried out for analyzing the influence of project delay reason. The reasons of the delay were driven from two different aspects (1) structural characteristic and (2) responsibility of the people involved in the project. The reasons that were identified from aforementioned three sections are the factors of the delay of the large-scale government driven projects. Finally, the author suggested the methodology of identifying the project delaying factors. The author also analyzed delay reasons in both the overseas and domestic cases of high rapid railway construction and has elicited some benchmarks for the future projects.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.172-173
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• 2015

Construction project involves numerous repetitive operations. Especially in high-rise and apartment houses projects, the amount of repetitive operations increase and a preceding operations delay causes serious damage to the total duration of the project. This study deducts work delay factors by site engineer interview and survey. The study analyzes daily report data to deduct crucial processes affecting masonry work which has been investigated to be one of preliminary processes conducted at the beginning of finish work.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.264-265
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• 2017

This paper aims to analyze relations between design errors prevented by building information modeling (BIM)-based design validation and their impacts in order to identify critical consideration factors for successfully implementing BIM-based design validation in the architecture, engineering, and construction (AEC) projects. More than 800 design errors detected by BIM-based design validation in two BIM-based projects in South Korea are categorized according to its causes and work types. The relations between causes and work types of design errors and project delay, cost overrun, low quality, and rework generation that can be caused by the errors are analyzed through conducting logistic regression. Characteristics of each design error are analyzed by conducting face-to-face interviews with practitioners in the two BIM-based projects. As the results, the impacts of design error causes on predicting project delay, cost overrun, low quality, and rework generation were the highest.

• Explosives and Blasting
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• v.32 no.2
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• pp.1-8
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• 2014

In this study, 16 test blastings had been carried out with different spacings, burdens, drilling lengths, and charges per delay for investigating the characteristics of ground vibration propagation, which depends on the delay time. From the tests, it was possible to derive a ground vibration equation. Using the equation, the characteristics of ground vibration could be investigated by analyzing the nomogram and predicting the Peak Particle Velocity (PPV), which are influenced by the delay time and the priming location. The trend of ground vibration change depending on the delay time was analyzed for the standards charges of 0.5, 1.6, 5, and 15 kg, which were suggested in "Blasting design and construction guidelines to road construction" by the Ministry of Land, Infrastructure and Transport. From the study, it would be possible to suggest a favorable vibration control method, which depends on the charge.