• Title/Summary/Keyword: Number and Operation

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The Impact of Climate Change on Future Aircraft Operation (기후변화에 따른 미래 항공기 운영 환경 변화)

  • Su-Yeon Park;Sang-Hwan Park;Keon-Hee Lee;Hye-Jeong Jung;Gyeong-Min Kang;Gong-Yo Kim;Jae-Don Hwang;Sung Kim
    • Atmosphere
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    • v.34 no.3
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    • pp.273-281
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    • 2024
  • Analyzing the information about climate change on Korean Peninsula is essential for the national defense. In this study, we used HadGEM3-RA model output (a member of CORDEX-EA) and analyzed the 3 operational weather factors (VMC, runway temperature, WBGT), which affect the aircraft field. The number of future limited days was quantitatively calculated based on the model outputs applying SSP1-2.6 and SSP5-8.5 and the operational limits of the previous three factors, and the spatial distribution, time series, and correlation of each result were analyzed. In conclusion, it was analyzed that the number of limited days by VMC would decrease, resulting from the rise in temperature and the drop in relative humidity. This means the operational environment in VMC will improve. On the other hand, the number of limited days by the runway temperature and WBGT would increase, resulting from the rise in temperature. This means the operational environment in runway temperature and WBGT will worsen.

Optimal Soft-combine Zone Configuration in a Multicast CDMA Network (멀티캐스트 CDMA 네트워크에서의 Soft-combine을 지원할 기지국의 선정)

  • Kim Jae-Hoon;Myung Young-Soo
    • Journal of the Korean Operations Research and Management Science Society
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    • v.31 no.3
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    • pp.1-10
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    • 2006
  • In this paper we deal with a cell planning issue arisen in a CDMA based multicast network. In a CDMA based wireless network, a terminal can significantly reduce the bit error rate via the cohesion of data streams from multiple base stations. In this case, multiple base stations have to be operated according to a common time line. The cells whose base stations are operated as such are called soft-combined cells. Therefore, a terminal can take advantage of error rate reduction, if the terminal is in a soft-combined cell and at least one neighboring cell is also soft-combined. However, as soft-combining operation gives heavy burden to the network controller, the limited number of cells can be soft-combined. Our problem us to find a limited number of soft-combined cells such that the benefit of the soft-combining operation is maximized.

A Domain-Partition Algorithm for the Large-Scale TSP (Large-Scale TSP 근사해법에 관한 연구)

  • Yoo, Hyeong-Seon;Kim, Hyun-Sng
    • Journal of the Korean Society for Precision Engineering
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    • v.9 no.3
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    • pp.122-131
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    • 1992
  • In this paper an approximate solution method for the large-scale Traveling Salesman Problem (TSP) is presented. The method starts with the subdivision of the problem domain into a number of cluster by considering their geometric characteristic. Each cluster has a limited number of nodes so as to get a local solution. They are linked go give the least pathe which covers the whole domain and become TSPs solution with start-and end-node. The approximate local solution in each cluster are obtained based on geometrical properties of the cluster, and combined to give an overall approximate solution for the larte-scale TSP.

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Operation and Generation Characteristic of 100MW-Class Wound Rotor Synchronous Generator According to Number of Slots (슬롯 수에 따른 100MW급 권선형 동기발전기 발전특성 및 운전특성 비교)

  • Kim, Chang-Woo;Park, Yo-Han;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.68 no.4
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    • pp.523-531
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    • 2019
  • This paper deals with a wound-field synchronous machines(WFSM), with an electromagnet on its salient rotor, as an alternative to a permanent magnet in the rotor. We then examine the power performance characteristics, loss characteristics, V-curves and large short-circuit ratios for a large-scale synchronous generator, considering the leading and lagging operations, based on the finite-element method. We predict the performance of a 100MVA-class generator based on the operating range for a constant short-circuit ratio. At the last, We compared with the electromagnetic characteristics of three model according to number of slots.

Two-Degree-of Freedom Fuzzy Neural Network Control System And Its Application To Vehicle Control

  • Sekine, Satoshi;Yamaguchi, Toru;Tamagawa, Kouichirou;Endo, Tunekazu
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1121-1124
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    • 1993
  • We propose two-degree-of-freedom fuzzy neural network control systems. It has a hierarchical structure of two sets of control knowledge, thus it is easy to extract and refine fuzzy rules before and after the operation has started, and the number of fuzzy rules is reduced. In addition an example application of automatic vehicle operation is reported and its usefulness is shown simulation.

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A study on efficient operation method of handling equipments in automated container terminals (자동화 컨테이너터미널에서 운송장비의 효율적인 운영방안)

  • 이상완;최형림;박남규;박병주;권해경;유동호
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.11a
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    • pp.63-70
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    • 2002
  • The main subject to become a hub pen is automation The automated container terminal has already operated in advanced pons and it bas been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the moat optimal method of equipment operation in order to minimize loading time using each three types of effective AT operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real tine. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and the number of AGVs).

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Control Method for Reducing Circulating Current in Parallel Operation of DC Distribution System for Building Applications (빌딩용 DC 배전 시스템의 병렬 운전 시 발생하는 순환전류를 저감시키기 위한 제어 기법)

  • Kim, Hack-Seong;Shin, Soo-Cheol;Lee, Hee-Jun;Jung, Chul-Ho;Han, Dong-Woo;Won, Chung-Yuen
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.3
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    • pp.256-262
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    • 2013
  • In the large system such DC distribution for building, the method that a number of modules converters operation in parallel is commonly used. When parallel operation, circulating current is directly related to the loss of the entire system. Accordingly, each module to share the same current is the most important for the safety of the power system. In this paper, control method for reducing circulating current in parallel operation is proposed. furthermore response and operation of steady-state with parallel system was verified by simulation and experiment results.

Analysis on the Distribution of Ship Arrival and the Cargo Handling Service of Inchon Port (인천항의 선박도착 분포 및 부두서비스 실태 분석에 관한 연구)

  • Hwang, H.S.;Kwak, K.S.
    • Journal of Korean Port Research
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    • v.11 no.1
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    • pp.45-64
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    • 1997
  • Ship's delay caused by port congestion has drawn attention to the necessity for analysis on overall operation in port. But, in order to analyze the complicated port operation which contains large number of variable factors, queueing theory is needed to be adopted, which is applicable to a large scale transportation including ship's arrival in a large port. In this paper, a simulation model for Inchon Port was developed by the software SIMAN V and presented congestion rate under a certain scenario regarding the arrival ship's number and service levels. To develop the simulation model, types of ships and cargoes during the 1995 in Inchon Port was analyzed in advance. The results of the simulation can be summarized as follows : In order to maintain present levels of congestion rate and time with the increasing number of arrival vessels, service rate should be increased at an exponential rate. To improve the current congestion effectively, part of cargoes are needed to be transferred to a newly developing port. Results obtained from simulation can be used properly to prepare improved service levels and to plan appropriate investment strategies.

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A Design of a 8-Thread Graphics Processor Unit with Variable-Length Instructions

  • Lee, Kwang-Yeob;Kwak, Jae-Chang
    • Journal of information and communication convergence engineering
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    • v.6 no.3
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    • pp.285-288
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    • 2008
  • Most of multimedia processors for 2D/3D graphics acceleration use a lot of integer/floating point arithmetic units. We present a new architecture with an efficient ALU, built in a smaller chip size. It reduces instruction cycles significantly based on a foundation of multi-thread operation, variable length instruction words, dual phase operation, and phase instruction's coordination. We can decrease the number of instruction cycles up to 50%, and can achieve twice better performance.

Control of a batch reactor using iterative learning (반복학습을 이용한 회분식 반응기의 제어)

  • 조문기;방성호;조진원;이광순
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.81-86
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    • 1991
  • The iterative learning operation has been utilized in the temperature Control of a batch reactor. A generic form of feedback-assisted first-order learning control scheme was constructed and then various design and operation modes were derived through convergence and robustness analysis in the frequency domain. The proposed learning control scheme was then implemented on a bench scale batch reactor with the heat of reaction simulated by an electric heater. The results show a great improvement in the performance of control as the number of batch operations progressed.

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