• Title/Summary/Keyword: order system

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A Study on the Effect of the Inventory Policy on Military Supply Chain Performance - Focused on System Dynamics - (재고정책에 따른 군 공급체인 성과에 관한 연구 - 시스템 다이나믹스를 중심으로 -)

  • 안병기;김태현;문성임
    • Journal of the military operations research society of Korea
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    • v.28 no.2
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    • pp.1-19
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    • 2002
  • This study shows the effect of inventory policy change from supplier-based to customer-based. We focus on the service level, cost, and information distortion of the Military Supply Chain(MSC) with System Dynamics. We design MSC model according to field practician interviews by using Vensim. The simulation makes a comparison between supply-based inventory policy performances and order-based inventory policy performances. In order to evaluate the MSC performances, we measure the accumulation of backlog(service level), supply chain cost, and order percentage overshoot(information distortion). The results show that 1) changing inventory policy from supplier-based to end customer order-based gets a good customer service, reduces MSC cost, and prevents information distortion, 2) changing inventory policy from supplier-based to immediate customer order-based reduces a small amount of MSC cost and deteriorates customer service, and 3) supply level is main factor for MSC performances improvement. This study implicates the policy change makes a improvement of MSC performance without introducing information system.

Optimum Approximation of Linear Time - Invariant Systems by Low - Order Models

  • 김상봉
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.19 no.1
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    • pp.71-78
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    • 1983
  • A method is given for obtaining low-order models for a linear time-invariant system of high-order by minimizing a functional of the reduction error between the output response of the original system and the low-order model. The method is based on the Astrom's algorithm for the evaluation of complex integrals and the conjugate gradient method of Fletcher-Reeves. An example illustrating the application of this method is given for approximation of a 4-th order system to be used in the load frequency control of generator systems.

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THE N-ORDER ITERATIVE SCHEME FOR A SYSTEM OF NONLINEAR WAVE EQUATIONS ASSOCIATED WITH THE HELICAL FLOWS OF MAXWELL FLUID

  • Ngoc, Le Thi Phuong;Dzung, Nguyen Vu;Long, Nguyen Thanh
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.3
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    • pp.471-497
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    • 2022
  • In this paper, we study a system of nonlinear wave equations associated with the helical flows of Maxwell fluid. By constructing a N-order iterative scheme, we prove the local existence and uniqueness of a weak solution. Furthermore, we show that the sequence associated with N-order iterative scheme converges to the unique weak solution at a rate of N-order.

An Expery System for the Diagnosis of the Fault Type and Fault Loaction In the Distribution SCADA System (배전 SCADA 기능을 이용한 고장타입.고장위치 진단 전문가 시스템)

  • Go, Yun-Seok;Sin, Deok-Ho;Sin, Hyeon-Yong;Lee, Gi-Seo
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.11
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    • pp.1417-1423
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    • 1999
  • Distribution system can experience the diverse events instantly and permanently. Also, it can experience high impedance fault or line drop under unbalanced situation, Accordingly, it is difficulty to identify the fault location because that data collected from distribution SCADA system may include uncertainty. This paper proposes an expert system, which can infer the faulted location the quickly and exactly for the diverse events in the distribution system. The expert system utilizes distribution SCADA function and collected data, especially, the monitoring mechanism for the normal open position switches is adopted newly in order to recognize the fault type exactly. Also, automated fault location diagnosis strategy is developed in order to minimize the spreading effect of fault obtained from the error of the system operator. The proposed strategy is implemented in C language. Especially, in order to prove the effectiveness of proposed expert system, the several scenario is simulated for the given model system. The real feeders are selected as model system for the simulation.

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The Phase Noise prediction and the third PLL systems on 1/f Noise Modeling of Frequency Synthesizer (주파수합성기의 Phase Noise 예측 및 3차 PLL 시스템에서의 1/f Noise Modeling)

  • 조형래;성태경;김형도
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.4
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    • pp.653-660
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    • 2001
  • In this paper, we designed 2303.15MHz frequency synthesizer for the purpose of the phase noise prediction. For the modeling of phase noise generated in the designed system through introducing the noise-modeling method suggested by Lascari we analyzed a variation of phase noise as according as that of offset frequency. Especially, for the third-order system of the PLL among some kinds of phase noise generated from VCO we analyzed the aspect of 1/f-noise appearing troubles in the low frequency band. Since it is difficult to analyze mathematically 1/f-noise in the third-order system of the PLL, introducing the concept of pseudo-damping factor has made an ease of the access of the 1/f-noise variance. we showed a numerical formula of 1/f-noise variance in the third-order system of the PLL which is compared with that of 1/f-noise variance in the second-order system of the PLL. As a result, In case of txco we found the reduce rapidly along the offset frequency after passed through that phase-noise was -160dBc/Hz before passed through a loop at 10kHz offset frequency and -162.6705dBc/kHz after passed through the loop, -180dBc/Hz at 100kHz offset frequency and -560dBc/kHz after passed through the loop. We can notice that the variance of third-order system more occurs (or the variance of second-order system in connection with noise bandwidth and variance factor of second-order and third-order system.

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Production Planning and Order Receiving System for Capable-To-Promise in Supply Chain Management (SCM을 위한 납기확약기반 생산계획 및 수주시스템)

  • Kim, Nae-Heon;Noh, Seung-Jong;Wang, Gi-Nam;Rim, Suk-Chul
    • IE interfaces
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    • v.13 no.3
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    • pp.396-404
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    • 2000
  • For most order-based production, it is important to meet urgent orders from important customers while maintaining high on-time delivery rate for successful supply chain management. In this paper, we propose an approach and a structure of planning system to implement Capable-To-Promise which promises the delivery time to the received order. We suggest and compare a few alternative order receiving policies for CTP.

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Digital Optimal Contorl of Servomotor System Considering Torsional Vibration Characteristics (비틀림 진동특성을 고려한 서어보모터계의 디지털 최적제어)

  • Jo, Seung-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.6 no.4
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    • pp.52-60
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    • 1989
  • In order to control the transient torsional vibration of rotational shaft system, the torsional stiffness of it has been taken into account in modelling the plant. In this paper the observer and controller has been designed in two ways. One is to consider the torsional stiffness and the other is to idealize the rotational shaft as rigid body. The third order observer considering torsional stiffness shows stable response on computer simulation. When the observer is designed on assumption of the rotational shaft being rigid body, the reduced order observer shows stable response whereas the full order observer shows unstable response.

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ORDER SYSTEMS, IDEALS AND RIGHT FIXED MAPS OF SUBTRACTION ALGEBRAS

  • Jun, Young-Bae;Park, Chul-Hwan;Roh, Eun-Hwan
    • Communications of the Korean Mathematical Society
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    • v.23 no.1
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    • pp.1-10
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    • 2008
  • Conditions for an ideal to be irreducible are provided. The notion of an order system in a subtraction algebra is introduced, and related properties are investigated. Relations between ideals and order systems are given. The concept of a fixed map in a subtraction algebra is discussed, and related properties are investigated.

A Study on the Neural Network Diagnostic System for Rotating Machinery Failure Diagnosis (신경망을 이용한 회전축의 이상상태 진단에 관한 연구)

  • 유송민;박상신
    • Tribology and Lubricants
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    • v.16 no.6
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    • pp.461-468
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    • 2000
  • In this study, a neural network based diagnostic system of a rotating spindle system supported by ball bearings was introduced. In order to create actual failure situations, two exemplary abnormal status were made. Out of several possible data source locations, ten measurement spots were chosen. In order to discriminate multiple abnormal status, a neural network system was introduced using back propagation algorithm updating connecting weight between each nodes. In order to find the optimal structure of the neural network system reducing the information sources, magnitude of the weight of the network was referred. Hinton diagram was used to visually inspect the least sensitive weight connecting between input and hidden layers. Number of input node was reduced from 10 to 7 and prediction rate was increased to 100%.