• 제목/요약/키워드: Optimal control period

검색결과 371건 처리시간 0.033초

회전기계 계통을 가동시키는 직류전동기를 위한 데드비트저어기 설계 (Design of Deadbeat Controller for DC Motor Driving a Rotational Mechanical System)

  • 이흥재;송자윤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 B
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    • pp.579-582
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    • 1999
  • This paper presents a design method of deadbeat controller for DC motor driving a rotational system with gear. The results of sampling a continuous-data process does not guarantee that no ripples occur between the sampling instants in the continuous-data output, but the proposed deadbeat control system that consists of the integral controller and the full state observer, and zero order hold using in continuous systems, has many advantages of such as an output response without the ripple and reaching the steady state without error after a given sampling period and faster settling time than the optimal control system in the short sampling period. The results of case study through matlab simulation shown that the efficiency of the proposed controller for DC motor driving a rotational system with gear, is verified by comparing with optimal controller etc.

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A Study on Multi-Period Inventory Clearance Pricing in Consideration of Consumer's Reference Price Effect

  • Koide, Takeshi;Sandoh, Hiroaki
    • Industrial Engineering and Management Systems
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    • 제12권2호
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    • pp.95-102
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    • 2013
  • It is difficult to determine an appropriate discount price for daily perishable products to increase profit from a long-term standpoint. Even if the discount pricing is efficient to increase profit of the day, consumers memorize the sales price and they might hesitate to purchase the product at a regular price the following day. The authors discussed the inventory clearance pricing for a single period in our previous study by constructing a mathematical model to derive an optimal sales price to maximize the expected profit by considering the reference price effect of demand. This paper extends the discussion to handle the discount pricing for multiple periods. A mathematical analysis is first conducted to reveal the properties on an objective function, which is the present value of total expected profits for multiple periods. An algorithm is then proposed to derive an optimal price for asymmetric consumers. Numerical experiments investigate the characteristics of the objective function and optimal pricings.

전동차 출입문제어 계전기의 신뢰도예측을 통한 적정 교체주기 연구 (A Study on Evaluation of Optimal Replacement Period by Reliability Prediction for the Door Control Relay of EMU)

  • 한재현;김종운;구정서
    • 조명전기설비학회논문지
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    • 제28권7호
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    • pp.34-40
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    • 2014
  • In this paper, we want to know the optimal replacement cycle(time) for this study was performed. The optimal preventive replacement age can be fond by finding the value of time that minimizes the cost function(model of Barlow and Jardine). In addition, The reliability of the relay according to the service environment were studied. The use of the exchange relay period is longer, and maintenance cost rate(per hour) may increase, and also the reliability may cause a decline. In addition, considering the preventive maintenance and purchase order, a representative relay(RAX-L440-A type) life was calculated.

공동주택의 에너지 부하량 저감을 위한 블라인드 운영스케줄 검토 (Blind Optimal Operating Schedule for Reviewing the Energy Load Reduction of Apartment House)

  • 마쥔챠오;이준기;김성훈;이갑택;이경희
    • 동력기계공학회지
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    • 제20권4호
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    • pp.63-68
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    • 2016
  • In this study, through portion of the blind control which the user can adjust the deration and the main loads, night for energy reduction during the review of the energy difference between the cooling and heating load periods in order to present the best operation schedules of the blind control. The result, Cooling period, the venetian blind is installed the day or the day and night CASE adjusted to $0^{\circ}$ was identified as optimal for the operating schedule. Heating period, the day, without installed the blinds, the Venetian blind is installed only at night CASE adjusted to $0^{\circ}$ or $45^{\circ}$ angle of the slats, which have been identified as optimal for the operating schedule.

수송공정을 고려한 다분기 공정-저장조 망구조의 최적설계 (Optimal Design of Multiperiod Process-Inventory Network Considering Transportation Processes)

  • 서근학;이경범
    • 제어로봇시스템학회논문지
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    • 제18권9호
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    • pp.854-862
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    • 2012
  • The optimal design of batch-storage network by using periodic square wave model provides analytical lot sizing equations for a complex supply chain network characterized as multi-supplier, multi-product, multi-stage, non-serial, multi-customer, cyclic system including recycling and/or remanufacturing. The network structure includes multiple currency flows as well as material flows. The processes are represented by multiple feedstock/product materials with fixed composition which are very suitable for production processes. In this study, transportation processes that carry multiple materials with unknown composition are added and the time frame is changed from single period into multiple periods in order to represent nonperiodic parameter variations. The objective function of the optimization involves minimizing the opportunity costs of annualized capital investments and currency/material inventories minus the benefit to stockholders in the numeraire currency. The expressions for the Kuhn-Tucker conditions of the optimization problem are reduced to a multiperiod subproblem for average flow rates and analytical lot-sizing equations. The multiperiod lot sizing equations are different from single period ones. The effects of corporate income taxes, interest rates and exchange rates are incorporated.

Control of G/MX/1 Queueing System with N-Policy and Customer Impatience

  • Lim, Si-Yeong;Hur, Sun
    • Industrial Engineering and Management Systems
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    • 제15권2호
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    • pp.123-130
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    • 2016
  • We introduce a queueing system with general arrival stream and exponential service time under the N-policy, where customers may renege during idle period and arrival rates may vary according to the server's status. Probability distributions of the lengths of idle period and busy period are derived using absorbing Markov chain approach and a method to obtain the optimal control policy that minimizes long-run expected operating cost per unit time is provided. Numerical analysis is done to illustrate and characterize the method.

실제 날씨를 고려한 PV-MPPT 제어기의 최적 주기와 변량전압 (Optimum Control Period and Perturbation Voltage for PV-MPPT Controller Considering Real Wether Condition)

  • 류단비;김용중;김효성
    • 전력전자학회논문지
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    • 제25권1호
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    • pp.1-5
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    • 2020
  • Solar power generation systems require maximum power point tracking (MPPT) control to operate PV panels at their maximum power point (MPP). Most conventional MPPT algorithms are based on the slope-tracking concept. A typical slope-tracking method is the perturb and observe (P&O) algorithm. The P&O algorithm measures the current and voltage of a PV panel to find the operating point of the voltage at which the calculated power is maximized. However, the measurement error of the sensor causes irregularity in the calculation of the generated power and voltage control. This irregularity leads to the problem of not finding the correct MPP operating point. In this work, the power output of a PV panel based on the P&O algorithm is simulated by considering the insolation profiles from typical clear and cloudy weather conditions and the errors of current and voltage sensors. Simulation analysis suggests the optimal control period and perturbation voltage of MPPT to maximize its target efficiency under real weather conditions with sensor tolerance.

다양한 납기일 형태에 따른 다제품 생산용 회분식 공정의 최적 생산계획 (Optimal scheduling of multiproduct batch processes with various due date)

  • 류준형
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.844-847
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    • 1997
  • In this paper, scheduling problem is dealt for the minimization of due date penalty for the customer order. Multiproduct batch processes have been dealt with for their suitability for high value added low volume products. Their scheduling problems take minimization of process operation for objective function, which is not enough to meet the customer satisfaction and the process efficiency simultaneously because of increasing requirement of fast adaptation for rapid changing market condition. So new target function has been suggested by other researches to meet two goals. Penalty function minimization is one of them. To present more precisely production scheduling, we develop new scheduling model with penalty function of earliness and tardiness We can find many real cases that penalty parameters are divergent by the difference between the completion time of operation and due date. That is to say, the penalty parameter values for the product change by the customer demand condition. If the order charges different value for due date, we can solve it with the due date period. The period means the time scope where penalty parameter value is 0. If we make use of the due date period, the optimal sequence of our model is not always same with that of fixed due date point. And if every product have due date period, due date of them are overlapped which needs optimization for the maximum profit and minimum penalty. Due date period extension can be enlarged to makespan minimization if every product has the same abundant due date period and same penalty parameter. We solve this new scheduling model by simulated annealing method. We also develop the program, which can calculate the optimal sequence and display the Gantt chart showing the unit progress and time allocation only with processing data.

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병원의 표준 혈액재고량 산출식 개발 (Development of the Standard Blood Inventory Level Decision Rule in Hospitals)

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

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홍수기중 가변제한수위에 의한 저수지 운영 (Reservoir Operation by Variable Restricted Water Level during Flood Period)

  • 심명필;권오익;이환기
    • 물과 미래
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    • 제28권6호
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    • pp.217-228
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    • 1995
  • 홍수기중 최적의 저수지운영을 위해 서로 상반되는 이수와 치수를 조화시키기 위한 전반적이고 체계적인 운영방안을 제안하였다. 본 연구는 비홍수기의 용수수요 보장을 고려히 홍수기중 저수지의 제한수위를 결정하기 위한 것이다. 단기간별요 가변제한수위(VRWL)와 최소 확보저수위 (MRWL)를 적용하여 저수용량의 재할당으로 최적 운영방안이 유도되었다. 또한 갈수빈도해석에 따른 저수지운영분석으로 비홍수기의 용수공급을 위해 확보되어야 할 홍수기말 저수지의 수위조건에 관하여 대청과 충주 다목적댐을 대상으로 적용하고 그 결과를 분석하였다.

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