• Title/Summary/Keyword: Operation Problem

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Application of Neural Networks to the Bus Separation in a Substation (신경회로망을 이용한 변전소 모선분리 방안 연구)

  • Lee, K.H.;Hwang, S.Y.;Choo, J.B.;Youn, Y.B.;Jeon, D.H.
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.757-759
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    • 1996
  • This paper proposes an application of artificial neural networks to the bus-bar separation in a substation for radial network operation. For the effective bus-bar operation, the insecurity index of transmission line load is introduced. For the radial network operation. the constraints of bus-bar switch is formulated in the performance function with the insecurity index. The determination of bus-bar switching is to find the states of 0 or 1 in the circuit breakers. In this paper, it is tested that the bus-bar separation of binary optimization problem can be solved by Hopfield networks with adequate manipulations.

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EEG signal display as a multirate sampling problem (멀티레이터 샘플링 문제로서의 뇌파신호 디스플레이)

  • Choi, H.G.;Oh, Y.S.;Lee, S.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.311-314
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    • 1996
  • The display of biological signals in monitors often involves a multirate sampling operation which consists of decimation and intenolation. All electroencephalographic (EEG) samples of 10 to 30 seconds must be displayed in the computer screen to keep the aspect ratio of the paper polygraph output. Since the current affordable display technology plots at most 2,000 pixels per row, some samples need to be discarded. This paper studies methods to perform this operation characterizing them from the signal processing viewpoint and compares the display quality among several decimations. Experimental results show that a nonlinear operation such as the peak detection could be preferable than the canonical linear filtering to reduce aliasing.

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A Study on Three Parallel Operation Control Algorithm of Thyristor Dual Converter System for Urban Railway Substation (도시 철도용 사이리스터 듀얼 컨버터 시스템의 3병렬 운전 제어 기법에 관한 연구)

  • Kim, Sung-An;Han, Sung-Woo;Cho, Yun-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.2
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    • pp.459-467
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    • 2017
  • An urban railway power substation consists of three thyristor dual converters. Two converters are connected to up and down trolley line to supply the electric energy or feed the regenerative energy back to the distribution. When the two converters break down, the remaining converter is used in an emergency. One thyristor dual converter system (TDCS) manages the energy of two or three railway stations. If the TDCS fails, the trains stop operating. To solve the problem, this paper proposes the three parallel operation control algorithm of thyristor dual converter system using the emergency converter. The broken TDCS can be replaced by the emergency converter in other TDCS. The effectiveness of this proposed control is verified by simulation.

Realization of Two-bit Operation by Bulk-biased Programming Technique in SONOS NOR Array with Common Source Lines

  • An, Ho-Myoung;Seo, Kwang-Yell;Kim, Joo-Yeon;Kim, Byung-Cheul
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.4
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    • pp.180-183
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    • 2006
  • We report for the first time two-bit operational characteristics of a high-density NOR-type polysilicon-oxide-nitride-oxide-silicon (SONOS) array with common source line (CSL). An undesired disturbance, especially drain disturbance, in the NOR array with CSL comes from the two-bit-per-cell operation. To solve this problem, we propose an efficient bulk-biased programming technique. In this technique, a bulk bias is additionally applied to the substrate of memory cell for decreasing the electric field between nitride layer and drain region. The proposed programming technique shows free of drain disturbance characteristics. As a result, we have accomplished reliable two-bit SONOS array by employing the proposed programming technique.

Control Method for Cut-out of Shorted Load in the Auxiliary Power Supply (보조전원장치의 단락부하 차단기 개방을 위한 제어방법)

  • 황광철;조국춘;최종묵
    • Proceedings of the KSR Conference
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    • 1998.11a
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    • pp.249-254
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    • 1998
  • This paper describes the control methods to cut out the NFB(No Fuse Breaker) of shorted load in the auxiliary power supply, Generally, when the short-circuit occurs in the load of the auxiliary power supply, the auxiliary power supply stops the operation according to the protection sequence. Finally, the other auxiliary power supply stops the operation by the same fault, To resolve this problem, we suggest the control method to trip the NFB of shorted load. That is, when the short circuit occurs, the controller changes control mode from voltage mode to current mode without the operation of output contactor(SIVK) in the auxiliary power supply. The auxiliary power supply provides a large current for the short-circuit load. After some time, the NFB of the short-circuit load is cut off and the auxiliary power supply Provides stable voltage for the loads except for the short-circuit load.

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A Design and Performance Evaluation of Concurrent Synchronization System of Multiple Client on a Mobile Environments (모바일 환경에서 다수 클라이언트의 동시 동기화 시스템 설계 및 성능 평가)

  • Kim, Hong-Ki;Kim, Dong-Hyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.217-220
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    • 2009
  • The two-way synchronization system in mobile environment processes synchronization of multi clients by order. In this case, that a synchronization operation, which takes long time to process, makes other clients wait is a problem. In this paper, treats to design and materialize a system which processes synchronization operations between clients without update conflicts as using multi queues. Also, compares performance between the simultaneous synchronization and the synchronization in consecutive order by the rate of process term of synchronization operation and the pattern of operation process.

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A War-time Engineering Equipment's Assignment and Operation Model (전시 공병장비 할당 및 운용 모형)

  • Jae-Hyeong Lee;Moon-Gul Lee
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.46 no.4
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    • pp.294-303
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    • 2023
  • During wartime, the operation of engineering equipment plays a pivotal role in bolstering the combat prowess of military units. To fully harness this combat potential, it is imperative to provide efficient support precisely when and where it is needed most. While previous research has predominantly focused on optimizing equipment combinations to expedite individual mission performance, our model considers routing challenges encompassing multiple missions and temporal constraints. We implement a comprehensive analysis of potential wartime missions and developed a routing model for the operation of engineering equipment that takes into account multiple missions and their respective time windows of required start and completion time. Our approach focused on two primary objectives: maximizing overall capability and minimizing mission duration, all while adhering to a diverse set of constraints, including mission requirements, equipment availability, geographical locations, and time constraints.

Locating export containers in order to minimize the number of rehandles (재취급을 최소화하기 위한 수출컨테이너 장치위치 결정법)

  • 김갑환;박영만
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.473-476
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    • 1996
  • In order to reduce the number of rehandles during the loading operation of export containers in port container terminals, the storage location of each arriving container should be determined considering of its weight. We formulate the problem by a dynamic programming model to get the optimal storage location.

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A Study on the Effective Stabilizing Countermeasure to First Swing Instability (제1파 동기탈조에 대한 효율적인 안정화 대책에 관한 연구)

  • Park, J.S.
    • Proceedings of the KIEE Conference
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    • 2008.11b
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    • pp.98-99
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    • 2008
  • The first swing instability is the very important problem in power system operation. In this paper, the effective countermeasures to the instability. We studied the reinforcement of the transmission lines, generation tripping and reactive compensation are considered as alternative to improve transient stability.

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A Study on Construction Lifts (건설용 LIFT에 대한 연구)

  • 김상렬;이정호;김일종
    • Journal of the Korean Society of Safety
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    • v.8 no.2
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    • pp.78-86
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    • 1993
  • This study was aimed at analyzing the mangment system and problem situation related to the lift operation. To this end, 61 construction sites of‘H’construction Co., througnout the nation were surveyed for March 1992-May 1992.

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