• Title/Summary/Keyword: Delay Factors

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Extended Integral Control with the PI Controller (확장적분 제어개념을 도입한 PI 제어기에 관한 연구)

  • Ryu, Heon-Su;Jeong, Gi-Yeong;Song, Gyeong-Bin;Mun, Yeong-Hyeon
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.7
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    • pp.345-349
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    • 2000
  • This paper presents an extended integral control with the PI controller by introducing the delay and decaying factors. The extended integral control scheme is developed by substituting the proportional convolution integral control for the PI(Proportional Integral) control. So far, the integral part of PI controller produces a signal that is proportional to the time integral of the input signal to the controller. The steady-state operation points are affected forever by errors in the past due to the input signal containing the information of the error in the past. These phenomena may cause some disturbances for other control purposes related to the given PI control. Introduction of forgetting factors to the error in the past can resolve the disturbance problems. Various forgetting factors are developed using the delay elements, the decaying factors, and the combination of the delay and decaying factors. The proposed various extended integral control schemes can be applicable to the corresponding PI control designs in which the error in the past may badly affect the current steady-state operation points and may cause some disturbances for other control purposes.

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LQ-PID Controller Tuning for a Second-Order System with Time-Delay (시간지연을 갖는 2차 시스템의 LQ-PID제어기 동조)

  • Park, Taek-Seon;Suh, Byung-Suhl
    • Proceedings of the KIEE Conference
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    • 2002.11c
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    • pp.67-70
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    • 2002
  • This paper presents an optimal robust LQ-PID controller design method for a second order system with time-delay to meet design specifications. By LQR formulation of the second order system with time-delay, tuning parameters of PID controller are related by the weighting factors Q and R of cost function. The selection of the weighting factors Q and R are chosen to satisfy such the design specifications as overshoot and settling time.

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CONSTRUCTION DELAY IN INTERNATIONAL PROJECTS: WITH SPECIAL REFERENCE TO GULF AREA CAUSES, DAMAGE ASSESSMENTS AND ENTITLEMENTS

  • Sami Fereig;Nabil Kartam
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.758-763
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    • 2005
  • For international projects in general and the projects in the Gulf area in Particular, the most common cause of construction disputes and claims is construction delay. This paper will present different surveys to identify the causes of delay, the parties responsible, and how delay can be avoided. This paper will outline how these factors impact damage assessment and entitlement. Furthermore, a case study will be presented to show how the responsibility and damages due to delay are assessed and how entitlements are calculated.

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A Study on the Critical Meteorological Factors Influencing the Flight Cancelation and Delay: Focusing on Domestic Airports (국내 항공운항에서 기상현상이 결항 및 지연에 미치는 영향 분석)

  • Lee, Joong-Woo;Ko, Kwnag-Kun;Kwon, Tae-Sun;Lee, Ki-Kwang
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.19 no.1
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    • pp.29-37
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    • 2011
  • Last April, Europe was severly damaged as all social and economic activities came to a halt prompted by the cancellation of all flights resulting from volcanic ash. This exemplifies that the meteorology conditions have significant influence on the flights of airplanes. Hence, in this research the influence that the meteorology has on the domestic flights and its characteristics will be examined, and the core meteorological factors that influence flights in each airport will be drawn. In order to do this, statistical analysis on the influence that the meteorology has on flights was carried out in order to analyze the data about flight cancelation and delay and also its cause, primarily based on the Gimpo, Gimhae, and the Jeju airports. As a result, first, the meteorological factors which impact flight cancellation and delay were different among the domestic airports, and second, it was analyzed that fog was the main meteorological factor in the Gimpo airport, strong wind in the Jeju airport, and fog in the Gimhae airport. Third, between the day the flights were cancelled and delayed occurred, and the day that weren't, the fact that there existed a difference among the actual meteorological factors was statistically drawn. With the result of such analysis, meteorological factors pertaining to the cancellation and delay of flights must be considered seperately by each airport and specialized meteorological information must be provided accordingly. Further, when selecting the position of an airport that is to be constructed in the future, implications that there is a definite need for the meteorology effect evaluation based on past meteorology data can be drawn.

Construction Delays in Developing Countries: A Review

  • Islam, Muhammad Saiful;Trigunarsyah, Bambang
    • Journal of Construction Engineering and Project Management
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    • v.7 no.1
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    • pp.1-12
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    • 2017
  • Construction delay is one of the basic constrains to achieve the project objectives in developing countries. This study aims to find the causes and effects of construction delays in developing countries. A thorough literature review has been done following the content analysis method. The relevant literature of 28 developing countries was collected from the scholarly journals published in the period of 2006 to 2016. The different developing countries are grouped into three geographic regions, i.e. South and Southeast Asia, Middle East, and Africa. In these regions, total 53 potential causes of delay under 8 major groups are identified. Frequency and ranking of these factors have been done. The factors, delay in progress payment by owner, contractors' cash flow problem, improper planning and scheduling, poor site management, and change order by owner during construction, are acknowledged as critical causes of delay in developing countries. This study will assist both academic and professional experts providing more insight about the construction delays and project management in developing countries.

Regression Technique-based Productivity Estimation conducting Construction Delay Factor Analysis on Interior Works in High-rise Building Construction (공기지연요소분석을 이용한 회귀분석 기반 초고층 내부공사의 생산성 예측)

  • Kim, Hyun-mi;Kim, Tae-Hyung;Shin, Young-Keun;Kim, Young-Suk;Han, Seungwoo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.191-192
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    • 2011
  • The construction projects contain a lot of variables and risk affecting productivity. The duration of the project must be recognized important as for quality, unit cost and safety. There is need for improving work efficiency by investigating relationship of works to prevent delay. This study focuses on analysing the delay factors of steel staircase system to suggest regression model that enables construction productivity estimation. The position of the observers and construction delay factors were expressed by the independent variable of the regression model and productivity was expressed by a dependent variable. This paper suggests quantitative productivity and it is expected that will be helpful estimating application in construction new technologies.

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A Pilot Study on Factors Associated with Presentation Delay in Patients Affected with Head and Neck Cancers

  • Baishya, Nizara;Das, Ashok Kumar;Krishnatreya, Manigreeva;Das, Anupam;Das, Kishore;Kataki, Amal Chandra;Nandy, Pintu
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.11
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    • pp.4715-4718
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    • 2015
  • Background: Patient delay can contribute to a poor outcome in the management of head and neck cancers (HNC). The main objective of the present study was to investigate the factors associated with patient delay in our population. Materials and Methods: Patients with cancers of the head and neck attending a regional cancer center of North East India were consecutively interviewed during the period from June 2014 to November 2014. The participation of patients was voluntary. The questionnaire included information on age, gender, residential status, educational qualification, monthly family income, any family history of cancer, and history of prior awareness on cancer from television (TV) program and awareness program. Results: Of 311 (n) patients, with an age range of 14-88 years (mean 55.4 years), 81.7% were males and 18.3% females (M:F=4.4). The overall median delay was 90 days (range=7 days-365 days), in illiterate patients the median delay was 90 days and 60 days in literate patients (P=0.002), the median delay in patients who had watched cancer awareness program on TV was 60 days and in patients who were unaware about cancer information from TV program had a median delay of 90 days (p=0.00021) and delay of <10 weeks was seen in 139 (44.6%) patients, a delay of 10-20 weeks in 98 (31.5%) patients, and a delay of 20-30 weeks in 63 (20.2%) patients. Conclusions: Education and awareness had a significant impact in reduction of median patient delay in our HNC cases.

Delay Factors Based on the Importance of Finish Work in Apartment Construction Project (공동주택 마감공사 중요도 기반 작업지연 요인 분석)

  • Lee, Seung-Hoon;Lee, Sang-Hyo;Kim, Ju-Hyung;Kim, Jae-Jun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.125-129
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    • 2010
  • The ultimate goal of construction is to complete the given work in the most economical and safest way within the required construction period while meeting the quality standards specified in the design drawing. There are a few characteristics of finish work. First, executed in subdivided processes, finish work involves a very diverse and complex structure. Second, there are no criteria for each segmented process with regard to the appropriate time of input. Third, it is not very necessary to set priorities for lead and lag works. This study intends to provide information on the completion of a project in accordance with the required duration by setting priorities in the delay of each detailed process of finish work to minimize delay in finish work. In this study, finish work is divided into wet work and other types of finish work, and the importance of each process is classified based on the given details of each process. In addition, the study employs a survey to analyze delay factors of a designer, a constructor, and a supplier. Using the survey results, the study sets priorities in delay of final work to provide information on the completion of an apartment project within the planned construction period.

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Analytical Framework for Promoting Customer Participation in Benefit Delay Type Services

  • Cho, Myung-Rae
    • The Journal of Economics, Marketing and Management
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    • v.6 no.1
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    • pp.9-16
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    • 2018
  • Purpose - Benefit delay type services have a characteristic of benefit delay that does not immediately appear at the time of delivery of service. Due to a characteristic of benefit delay, the customer's participation in the service delivery system is hindered, and the quality of service declines. As a result, customer satisfaction would be reduced. The purpose of this study is to construct an analytical framework to analyze a mechanism that promotes customer participation in benefit delay type services. Research design, data, and Methodology - Existing research has considered only the performance of service companies to enhance the quality of service and customer satisfaction. This study focused on customer participation as a factor affecting the quality of service and customer satisfaction and attempted to construct an analytical framework based on a theoretical perspective of motivational research. Results - By adopting the motivation theory, this research derived three concepts, the possibility of gaining benefits, the emotional experience, and the desire of benefit. And motivation is created when the three factors interact with each other. Conclusions - This paper has constructed an analytical framework for analyzing factors that promote customer participation in the benefit delay service and finally has proposed case study for further research.

Factors Affecting Discharge Delay in Lumbar Spinal Surgery Patients Who were Treated according to a Critical Pathway (표준진료지침을 적용한 요추 수술 환자의 퇴원 지연에 영향을 미치는 요인)

  • Kim, Jeoung Hee;Lee, Eun Ha;Kim, Su Ran;Kim, Sung Reul
    • Korean Journal of Adult Nursing
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    • v.28 no.1
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    • pp.43-52
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    • 2016
  • Purpose: The aim of this study was to identify demographic, clinical, physical, and psychosocial factors affecting discharge delay in lumbar spinal surgery patients who were treated according to a critical pathway. Methods: A sample of 170 patients with lumbar spinal surgery agreed to participate in the study, between April 1, 2014 and August 30, 2015. Data were analyzed by mean, standard deviation, t-test, ${\chi}^2$-test, ANCOVA, and logistic regression analysis using SPSS 22.0 program. Results: Approximately fifty-nine percent of the participants was delayed discharge. On logistic regression analysis, female gender (OR=2.63, 95% CI=1.40~4.94), age (OR=1.03, 95% CI=1.01~1.05), spondylolisthesis (OR=4.49, 95% CI=1.90~10.61), and spinal fusion operation (OR=4.14, 95% CI=1.89~9.05) were significant factors predicting discharge delay of the participants. However, discharge delay was not related with pain, physical function, depression, or family support. Conclusion: An analysis of discharge delay may assist in evaluating and revising critical pathway for optimal care. In addition, nurses need to understand the factors affecting discharge delay of the given population who were treated according to a critical pathway.