• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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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.

• 한국IT서비스학회지
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• 제3권2호
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• pp.65-84
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• 2004

This research analyzes the causes of delay and resulting additional expenses on the IS project in the public sector, and then proposes some solutions to the problem. Through a field study, the research found that the causes include employer's attitude, the leadership and risk management ability of the project manager, and qualifications of project members. In order to avoid those problems, the project manager should secure various communication channels and good relationship between the employee and the contractor.

• 한국자동차공학회논문집
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• 제2권6호
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• pp.76-86
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• 1994

Combustion of diesel engine depends on the mixing of air and evaporating fuel during ignition delay greatly. Variation of air-fuel mixing rate and ignition delay for engine operating condition causes difference of combustion, performance and exhaust emissions. This study is investigated in a turbocharged diesel engine of IDI swirl chamber type. In the results, As injection timing is advanced until $12.6^{\circ}$ BTC, ignition delay decreases. NOx concentration and smoke level in exhaust gas increases for advanced injection timing Ignition delay, combustion period, pressure rise rate and exhaust gas temperature are increased with increasing engine speed. And ignition delay at high load is more decreased than that at low load. Ignition delay and combustion period are decreased with increasing intake pressure. Power increases, temperature and CO, NOx concentration in exhaust gas decreases as intake pressure increases. With increasing load, ignition delay is decreased and combustion period, motoring pressure are increased.

• Journal of Information Technology Applications and Management
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• 제12권3호
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• pp.129-150
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• 2005

Due to the advance of the Internet, the electronic commerce is getting more widely used, and customer's demand for the e-Commerce service quality is rapidly increasing. On the other hand, e-Commerce companies required the Internet services whose quality is provided more reliable service to their customers. Therefore, it is very important to provide both e-Commerce companies and customers with the measurement and service quality in real-life network environment. But the research on the service quality measurement method for electronic commerce systems has been limited because ISP and e-Commerce providers seldom disclose detailed service measures such as, where and how much service delay incurred. In this paper, we construct sample e-Commerce systems and try to measure the service quality of the systems in real network environment. We have analyzed the delay zones and causes using a measurement tool. We must reflect the improvement method against delay causes. Accordingly, the customers can be experiences the better service quality. We hope that this research will be the groundwork for future research on the service quality of various types of e-Commerce systems and online services.

• 전기의세계
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• 제20권4호
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• pp.17-22
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• 1971

This paper deals with the analytic structure of feedback controller for linear time invariant discrete systems. On the way of developing the deadbeat controller, some necessary conditions for control policy have been derived. In the case of time delay, it was proved that the q periods delay in the control causes q periods delay in the point at which deadbeat response occurs. Theorems and conclusions are illustrated with some simple nontrivial numerical examples and signal state tracking application problems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.82.1-82
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• 2001

It is known that existence of irregular transmission time delay is a major bottleneck for application of advanced robot control schemes to internet telerobotic systems. In the internet teleoperation system, the irregular transmission time delay causes a critical problem, which is unstable and inaccurate. This paper suggests a practical internet teleoperation system with streaming buffer system, which consists of a buffer, a buffer manager, and a control timer. The proposed system converts the irregular transmission time delay to constant. So, the system effectively transmits the control input to a remote site to operate a robot stably and accurately. This feature enables short control input interval. That means the entire system has ...

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.161-165
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• 2015

The delay in construction is the challenge often faced in the course of executing construction projects. To the government projects, the delays become very serious. This problem directly affects the lives, social welfare of the people, and the other negative social impacts. However, the government projects have not been much interest. The questionnaire surveys in Vietnam were conducted to determine the causes of the delay and to find solutions for dealing with the delay. The average index was used to rank the delay factors and the solutions. This study identified the 5 most highly ranked delay factors and the 8 best solutions from a list of 31 delay factors and 19 solutions for the delay. The five most highly ranked delay factors were: information delays and lack of information exchange between the parties; incompetent owner; incompetent supervision consultant; incompetent contractor; and difficulties in financing project by owner. The findings of the study can help the parties involved the government construction projects and practitioners to give appropriate strategies for countering the delay in their projects.

• 한국군사과학기술학회지
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• 제12권6호
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• pp.719-726
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• 2009

A delay system in fuze for high explosive shell is an important safety device, but failure in the delay system usually causes failure of the shell. Root-cause analysis of failure in the delay system is required since failure in over 10-years stored delay system recently occurs. In this paper, failure in the delay system was reproduced experimentally to examine aged characteristics of the delay system, and the failed delay system shows the same characteristics as ones of failed delay systems in field. Based on the reproduced experiments, accelerated life testings and the data analysis of failure times of delay systems were performed to predict the storage lifetime.

• 한국건축시공학회지
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• 제20권6호
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• pp.527-535
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• 2020

본 연구에서는 EPC/턴키 프로젝트에서 발생 가능한 클레임의 주요 원인들을 발주자와 건설사의 관점에서 분석하였다. 그 원인들은 EPC/턴키 프로젝트의 표준 계약서인 FIDIC 실버 북을 기반으로 도출하였다. 발생 빈도가 가장 높은 클레임의 유형은 공기지연으로 분석되었다. 그 후, 가장 발생 빈도가 높은 클레임에 대한 책임이 계약 당사자간에 누구에게 있는지를 분석하는 프로세스를 제안하였다. 제안된 프로세스는 2010년에 수행한 2건의 대규모 EPC/턴키 프로젝트들과 FIDIC 실버 북의 공기지연 클레임에 관련된 계약 조항들을 기반으로 제안되었다. 제안된 프로세스는 발주자가 공사기간 지연에 대해 배상금을 설정하는지에 대한 의도에 따라 분류된다. 본 연구의 주요 기여도는 사례 프로젝트의 계약 조건을 기반으로 다양한 계약 유형에 적용할 수 있는 프로세스를 제안한 것이다. 뿐만 아니라, 계약서 작성 전에 발생 가능한 클레임의 유형을 확인할 수 있고, 공사기간 지연 클레임이 발생할 경우에 책임 당사자를 예측할 수 있으므로, 명확한 계약서 작성에도 기여할 수 있을 것이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1120-1124
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• 2005

We reviewed controllers with a time delay estimation in this paper. Time delay control (TDC) and sliding mode control (SMC) are well known robust control schemes. Basically, the TDC has a main characteristic called a time delay estimation from which we can estimate the total uncertainty of a system. . The TDC causes the stick-slip in the case of systems with a friction. The so-called TDCSA which are short for TDC with switching action was developed to reduce the stick-slip. The TDC has the additional switching action term in the TDC structure. In the other hand, the SMC dose not have a time delay estimation but instead it can estimate the system uncertainty through the switching action. The SMC has a difficulty to estimate the total uncertainty of a system because it does not have a time delay estimation. In order to solve the difficulty, some control schemes were developed. Among them, we need to focus our attention on two control schemes: SMCPE and SMCTE, which are short for sliding mode control with a perturbation estimation and sliding mode control with a time delay estimation, respectively. In this paper, we analyzed and compared the characteristic of above three controllers. Even though the motives for the development of three control schemes are different, three control schemes have much in common in terms of their controller structures.