• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2006년도 학술발표회 논문집
• /
• pp.746-751
• /
• 2006

The geumjunggu of the onchunchun which is the upper stream have been maintained as a too much picture to become a concrete lining about existing low flow channel and the reservoir water protecting banks for the reason of the flow of an upper stream steep slope and back of the shortage of the channel area in a suitableness interval. This research made a rating-curve to decide since to ensure against risks to the flood control through the undo of the rivers. And we found the speed of current of a nature undo interval and existing concrete interval and water level change out. A result from this natural disposition we must apply as a data for the research about the plan to be established in the rivers maintenance basis plan of onchunchun.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
• /
• pp.723-729
• /
• 2005

Traditional statistical process control(SPC) applied to discrete part industry in the form of control charts can look for and eliminate assignable causes by process monitoring. On the other hand, engineering process control(EPC) applied to the process industry in the form of feedback control can maintain the process output on the target by continual adjustment of input variable. This study presents controlling and monitoring rules adopted variable sampling interval(VSI) to change sampling intervals in a predetermined fashion on the predicted process levels for integrated EPC and SPC systems. Twelve rules classified by EPC schemes(MMSE, constrained PI, bounded or deadband adjustment policy) and type of sampling interval combined with EWMA chart of SPC are proposed under IMA(1,1) disturbance model and zero-order (responsive) dynamic system. The properties of twelve control rules under three patterns of process change(sudden shift, drift and random shift) are evaluated and discussed through simulation and control rules for integrated VSI EPC and SPC systems are recommended.

• Journal of Electrical Engineering and Technology
• /
• 제12권2호
• /
• pp.959-968
• /
• 2017

Electrical safety monitoring System (ESMS) is a critical component in modern power systems, which is characterized by large-scale access points, massive users and versatile requirements. For convenience of the information integration and analysis, the software development, maintenance, and application in the system, the cloud platform based ESMS is established and assessed in this paper. Firstly the framework of the system is proposed, and then the assessment scheme with a set of evaluation indices are presented, by which the appropriate cloud product can be chosen to meet the requirements of a specific application. Moreover, to calculate the weights of the evaluation indices under uncertainty, an improved interval AHP method is adopted to take into consideration of the fuzziness of expert scoring, the qualitative consistency test, and the two normalizations in the process of eigenvectors. Case studies have been made to verify the feasibility of the assessment approach for ESMS.

• 유기물자원화
• /
• 제24권2호
• /
• pp.31-39
• /
• 2016

저수조는 유입/유출량의 시간적인 편차 때문에 필요하다. 저수조 용량 산정하기 위해서 공급(예, 강수) 누적 량과 요구(예, 관수) 누적 량의 차이를 사용한다. (-)와 (+)영역의 상관없이 누적 량 차의 절댓값 최대치가 되었을 때 용량의 산정이 이루어진다. 본 논문에서는, 온실 시설물의 강수와 관수를 이용하여 비선형적인 공급이나 요구량에서도 이를 적용하여 용량을 산정하였고, 비선형적인 변화가 커졌을 시에도 적용 할 수 있음을 증명하였다. 그리고 모니터링에 대한 시간 간격이 작아짐에 따라서, 저수조 용량이 증가되며, 강수량의 경우에는 약 10일을 변곡점으로 증가폭이 감소됨을 보인다.

• 조명전기설비학회논문지
• /
• 제27권4호
• /
• pp.16-22
• /
• 2013

This paper presents a method to analyze the voltage sag data obtained from monitoring systems. In order to establish effective countermeasures against voltage sag problems, an assessment of the system performance with respect to voltage sags is needed. Generally, the average annual sag frequency can be estimated by using the recorded voltage sag events for several years. However, the simple average value can not give the information about the errors of estimation. Such an average estimation is not useful for establishing effective solutions for voltage sag problems. Therefore, this paper proposes an effective method based on the Interval Estimation method. The estimation of voltage sag frequency is performed by using the average frequency and Poisson probability model. The proposed method can give the expected annual sag frequency and upper one-sided bound frequency.

• Journal of the Korean Data and Information Science Society
• /
• 제26권6호
• /
• pp.1593-1600
• /
• 2015

A control chart is very useful in monitoring various production process. There are many situations in which the simultaneous control of two or more related quality variables is necessary. We construct bivariate Shewhart control charts based on the trace of the product of the estimated variance-covariance matrix and the inverse of the in-control matrix and investigate the properties of bivariate Shewart control charts with VSI procedure for monitoring covariance matrix in term of ATS (Average time to signal) and ANSW (Average number of switch) and probability of switch, ASI (Average sampling interval). Numerical results show that ATS is smaller than ARL. From examining the properties of switching in changing covariances and variances in ${\Sigma}$, ANSW values show that it does not switch frequently and does not matter to use VSI procedure.

• Journal of the Korean Data and Information Science Society
• /
• 제20권4호
• /
• pp.741-747
• /
• 2009

Properties of multivariate Shewhart and EWMA (Exponentially Weighted Moving Average) control charts for monitoring variance-covariance matrix of quality variables are investigated. Performances of the proposed charts are evaluated for matched fixed sampling interval (FSI) and variable sampling interval (VSI) charts in terms of average time to signal (ATS) and average number of samples to signal (ANSS). Average number of swiches (ANSW) of the proposed VSI charts are also investigated.

• 대한산업공학회지
• /
• 제32권3호
• /
• pp.210-218
• /
• 2006

Traditional statistical process control (SPC) applied to discrete part industry in the form of control charts can look for and eliminate assignable causes by process monitoring. On the other hand, engineering process control (EPC) applied to the process industry in the form of feedback control can maintain the process output on the target by continual adjustment of input variable. This study presents controlling and monitoring rules adopted by variable sampling interval (VSI) to change sampling intervals in a predetermined fashion on the predicted process levels under integrated EPC and SPC systems. Twelve rules classified by EPC schemes(MMSE, constrained PI, bounded or deadband adjustment policy) and type of sampling interval combined with EWMA chart of SPC are proposed under IMA (1,1) disturbance model and zero-order (responsive) dynamic system. Properties of twelve control rules under three patterns of process change (sudden shift, drift and random shift) are evaluated and discussed through simulation and control rules for integrated VSI EPC and SPC systems are recommended.

• 응용통계연구
• /
• 제21권3호
• /
• pp.509-521
• /
• 2008

평균과 분산이 동시에 변화할 수 있는 공정을 관리할 경우, 평균의 변화를 탐지하는 관리도와 분산의 변화를 탐지하는 관리도를 병행하여 사용하는 것이 일반적이다. 여러 연구자들이 하나의 관리도를 사용하여 공정 평균과 분산의 변화를 동시에 탐지할 수 있는 절차를 제안했는데, 이 논문에서는 이와 같은 관리도들을 소개하고 그 효율을 비교하였다. 그 결과 GLR 관리도 Omnibus EWMA 관리도 그리고 Interval 관리도는 충분히 좋은 효율을 가짐을 알 수 있었다.

• 한국안전학회지
• /
• 제7권3호
• /
• pp.60-65
• /
• 1992

As many industrial workers have been involved with computer terminal tasks, for example, monitor ing, inspection, or computer da4a entry etc., concerns for difficulty evaluation of computer terminal tasks are Increased. This study provides that eyeblink can be used as a means of difficulty evaluation of a computer terminal lask. Four subjects without color blindness are asked to perform the monitoring task of the binary choice type under five levels of task difficulty. In each task, eyeblink rates and eyeblink interval times were measured from the subjects. The results show that the eyeblink rate does decrease with an Increase in task difficulty. In addition, it was found that both eyeblink interval time and eyeblink Interval time variation increased with an increase in task difficulty. It was concluded that the change of eyeblink rate, eyeblink interval time and eyeblink interval time and eyeblink interval time variation could be regarded as a generalized response to the imposition of task difficulty.