• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
• /
• pp.190-194
• /
• 1987

This paper describes a new method for control of large-scale system by sliding mode. The concepts of control to large-scale system on the basis of VSS(Variable Structure System) control theory are used to decompose a large control problem into a two-level algorithm such that each subsystem is stabilized with local discontinuous controllers and higher level corrective control is designed to take into account the effect of interaction among the subsystems. In this paper, we show that each subsystem is controlled with repect to local continuous and higher level corrective control. This algorithm can be easily applied to multi-variable control system and obtained a continuous control in comparison With variable structure control systems. Two numerical examples are discussed as illustrations.

• 유통과학연구
• /
• 제13권8호
• /
• pp.15-25
• /
• 2015

Purpose - There is a lack of research on how much corporate control is sufficient for effective subsidiary business-related decision making. To address this research gap, this study analyzes the impact of the level of control of a Korean corporation's headquarters on its overseas subsidiary performance. Research design, data, methodology - The study's sample comes from the Overseas Korean Business Directory of KOTRA. A multiple regression analysis empirically confirmed the relationship between the headquarters level of control over the subsidiaries and their performance. Results - The results show that the greater an organization's headquarters control over strategic issues, the greater the subsidiary's non-financial performance. However, quick decision-making through decentralization promotes the rapid selection of successful new products that can provide a competitive advantage. Conclusion - This study shows that the impact of control levels on subsidiary performance depends on the type of control involved. Specifically, while low levels of control over operational issues had a positive (+) influence on subsidiary non-financial performance, high control levels led to improved non-financial performance with regard to strategic issues among the subsidiaries.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제11B권3호
• /
• pp.64-69
• /
• 2001

Energy recovery in the regenerative region is very important when SRM is used in traction drive, This is to reduce en-ergy loss during mechanical braking and/or to have a high efficiency drive during braking To control excitation voltage in motor operation and regenerative voltage in the generator operation in the SRM multi-level voltage control is effective The paper sug-gests multi-level inverter which is useful for motoring and regenerative operation in SRM

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
• /
• pp.244-247
• /
• 1986

A revised two-level costate prediction algorithm is developed for the optimization of nonlinear nuclear power plant. The algorithm is proved to converge very well, and appears to require substantially small computation time and storage than previous nonlinear optimization algorithm. To cope with unknown external disturbances, we construct a closed loop control system. In order to get a smaller sampling time, this paper proposes the two-level Kalman filter.

• 대한간호학회지
• /
• 제18권2호
• /
• pp.118-127
• /
• 1988

This descriptive-correlational study was undertaken in order to examine if there was relationship between health locus of control and health behavior of 122 residents in Choong Nam Province. The sampling method was non-probability, conventent sampling technique. Questionnaire survey was conducted from March 2 to March 11, 1988. Each participant completed the Multidimensional Health Locus of control(MHLC) scale (Wallsten & Wallston, 1978) and Health Behavior scale (developed by Dr. cho) The collected data were analyzed using Peason Correlation coefficient, t-test and Analusis of Variance. The results were as follows : 1. Hypothesis 1, stating that the higer the score of internal health locus of control, the higher the Score of level of actual implementation of health behavior was supported(r＝.1344, p＜.05). 2. Hypothesis 2, stating that the higher the score of chance health locus of control, the lower the score of level of actual implementation of health behavior was not supported (r＝-.1344, p＞.05). 3. Hypothesis 3, stating that the higher the score of internal health locus of control, the higher the score of the level of perceived importance of health behavior was supported (r＝.3373, p＜.001). 4. Hypothesis 4, stating that the higher the score of chance health locus of control, the lower the score of level of perceived importance of health behavior was not supported (r＝-.0810, p＞.05). 5. The mean score of internal was 23.36, powerful others was 19.04 and chance 15.36 out of maximum range of 6-30 respectively. The mean score of level of actual implementation of health behavior was 112.84 and level of perceived importance of health behavior 143.60 our of maximum range of 32-160 respectively. 6. The variances which were related with the level of actual implementation of health behavior, were education level, occupation, economic status, referred method of primary health, management and resicent's place. And the variance which were related with the level of perceived importance of health behavior were sex, economic status and occupation.

• 한국정보통신학회논문지
• /
• 제25권7호
• /
• pp.923-929
• /
• 2021

TCP 통신, 패킷통신은 고품질과 고신뢰성 확보를 위해서는 전송제어 기술이 필요하다. 그러나 실시간 데이터 전송의 경우 비효율적 전송 문제가 발생한다. 이러한 문제점을 극복하여 패킷의 신뢰성 전송을 위해 일반적으로는 단순히 버퍼 수위를 지표로 하는 조기혼잡제어를 사용 하였다. 혼잡을 제어하는 시점을 버퍼 수위에 기준을 두기 때문에 혼잡제어 시점과 해지 시점의 제어가 지연된다. 따라서 본 논문에서는 버퍼 수위 지표뿐만 아니라 네트워크 혼잡을 측정하는 전송 속도와 버퍼 수위가 최적의 설정 이상 수준에 근접하도록 패킷 폐기확률을 결정하는 이상적인 버퍼 수위와 함께 분류 하였다. 제안 방법을 입증하기 위한 실험에서 설정한 이상적인 버퍼 수위에 의해 평균버퍼 수위가 유지되게 함으로 직접 제어할 수 있음을 결과로 나타내었다.

• 기본간호학회지
• /
• 제11권1호
• /
• pp.31-40
• /
• 2004

Purpose: The purpose of this study was to describe nurses' recognition of, and practice level in management of general nosocomial infections, and methicillin resistant staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE) infections. Method: A self-administered questionnaire was used to collect data. Data were collected on June, 2003 from 190 nurses in one university affiliated hospital located in Suwon. Result: The mean score for nurses' recognition of general nosocomial infection control was 3.57, MRSA control was 3.54, and VRE control was 3.86. The mean score on practice for control of general nosocomial infection was 3.19, for MRSA control, 3.20, and for VRE control, 3.63. There were statistically significant relationships between the recognition level and practice level for general nosocomial, MRSA, and VRE infection control. According to the general characteristics of the nurses, the mean scores for both recognition and practice were higher for those nurses who had had infection control education, for those who had worked longer in nursing, and for those who worked in the ICU. Conclusion: It is suggested that appropriate hospital infection control programs should be developed through continuous education and practice to improve nurses' level of the practice in general infection control, and especially in MRSA and VRE infection control.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.301-304
• /
• 1997

Two options arising during implementation of an advanced model-based control system on a process with low-level loops are discussed. Strengths and deficiencies of the options are examined and methods to overcome the deficiencies are proposed. Simulation results of a CSTR and distillation column are presented to demonstrate the performance improvements.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
• /
• pp.427-431
• /
• 1994

The objective of this paper is to provide an inventory control policy for the system that carries a single item with a multiple demand classes, when the demand is Poisson distributed random variable. The inventory control process includes the process of determining the reorder point, and the process of inventory control during the lead time. The goal of the optimization process is to achieve the service level of each demand class as well as the system-wide total service level at a preset desired service level while sustaining a minimum average inventory.

• Journal of Preventive Medicine and Public Health
• /
• 제21권1호
• /
• pp.195-206
• /
• 1988

Two major issues of the blood bank management are quality assurance and inventory control. Recently, in Korea blood donation has gained popularity increasingly to allow considerable improvement of the quality assurance with respect to blood collection, transportation, storage, component preparation skills and hematological tests. Nevertheless the inventory control, the other issue of blood bank management, has been neglected so far. For the supply of blood by donation barely meets the demand, the blood bank policy on the inventory control has been 'the more the better.' The shortage itself by no means unnecessitate inventory control. In fact, in spite of shortage, no small amount of blood is outdated. The efficient blood inventory control makes it possible to economize the blood usage in the practice of state-of-the-art medical care. For the efficient blood inventory control in Korean hospitals, this tudy is to develop formulae forecasting the standard blood inventory level and suggest a set of policies improving the blood inventory control. For this study informations of $A^+$ whole bloods and packed cells inventory control were collected from a University Hospital and the Central Blood Bank of the Korean Red Cross. Using this informations, 1,461 daily blood inventory records were formulated.48 varieties of blood inventory control environment were identified on the basis of selected combinations of 4 inventory control variables-crossmatch, transfusion, inhospital donation and age of bloods from external supply. In order to decide the optimal blood inventory level for each environment, simulation models were designed to calculate the measures of performance of each environment. After the decision of 48 optimal blood inventory levels, stepwise multiple regression analysis was started where the independent variables were 4 inventory control variables and the dependent variable was optimal inventory level of each environment. Finally the standard blood inventory level decision rule was developed using the backward elimination procedure to select the best regression equation. And the effective alternatives of the issuing policy and crossmatch release period were suggested according to the measures of performance under the condition of the standard blood inventory level. The results of this study' were as follows ; 1. The formulae to calculate the standard blood inventory level($S^*$)was $S^*=2.8617X(d)^{0.9342}$ where d is the mean daily crossmatch(demand) for a blood type. 2. The measures of performace - outdate rate, average period of storage, mean age of transfused bloods, and mean daily available inventory level - were improved after maintenance of the standard inventory level in comparison with the present system. 3. Issuing policy of First In-First Out(FIFO) decreased the outdate rate, while Last In-First Out(LIFO) decreased the mean age of transfused bloods. The decrease of the crossmatch release period reduced the outdate rate and the mean age of transfused bloods.