• 제목/요약/키워드: operation standard

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A Numerical Analysis on the Pressure Field Around KTX Train Using the Standard Framework of CFD Analysis for Railway System (철도시스템 전산유체해석 표준 프레임웍을 이용한 KTX 차량 주변 압력장에 대한 수치해석)

  • Nam, Sung-Won;Cha, Chang-Hwan;Kwon, Hyeok-Bin
    • Journal of the Korean Society for Railway
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    • v.9 no.5 s.36
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    • pp.511-516
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    • 2006
  • A standard framework of CFD(Computational Fluid dynamics) analysis for railway system has been developed to evaluate the overall aerodynamic performance of railway system and has been adopted to numerical simulation of the pressure field around KTX train. The framework is composed of standard aerodynamic model and standard aerodynamic performance to customize the general CFD solution process reflecting the characteristics of railway system such as various operation mode and performance factors. The results show that the standard framework of CFD analysis for railway system can provide objectivity and consistency to the CFD analysis for railway system and the pressure field around KTX train has been successively solved.

Novel Self-Reference Sense Amplifier for Spin-Transfer-Torque Magneto-Resistive Random Access Memory

  • Choi, Jun-Tae;Kil, Gyu-Hyun;Kim, Kyu-Beom;Song, Yun-Heub
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.1
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    • pp.31-38
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    • 2016
  • A novel self-reference sense amplifier with parallel reading during writing operation is proposed. Read access time is improved compared to conventional self-reference scheme with fast operation speed by reducing operation steps to 1 for read operation cycle using parallel reading scheme, while large sense margin competitive to conventional destructive scheme is obtained by using self-reference scheme. The simulation was performed using standard $0.18{\mu}m$ CMOS process. The proposed self-reference sense amplifier improved not only the operation speed of less than 20 ns which is comparable to non-destructive sense amplifier, but also sense margin over 150 mV which is larger than conventional sensing schemes. The proposed scheme is expected to be very helpful for engineers for developing MRAM technology.

A Study on TPS based on ATO for Driverless LRT (ATO 자동운전 기반의 무인운전 경전철 TPS에 관한 연구)

  • Lee, Chang-Hyung;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1132-1137
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    • 2008
  • Automatic Operation based on ATO (Automatic Train Operation) is necessary for driverless Light Rail Transit business. When this kind of driverless LRT operation plan is made, TPS (Train Performance Simulation) is traditionally simulated at all-out mode and coasting mode based on manual operation. Commercial schedule speed equals to all-out speed minus $9{\sim}15%$ make-up margin. Coasting mode TPS simulation is also run at commercial schedule speed to calculate run time and energy consumption. But TPS based on manual operation should make an improvement on accuracy in case of driverless LRT operation Plan. In this paper, new fast mode TPS simulation using ATO pattern is proposed and show near actual ATO result. The actual ATO pattern can be accurately simulated with the introduction of 4 parameters such as commercial braking rate, jerk, station stop profile and grade converted distance. Normal mode TPS simulation for commercial schedule speed can be designed to have fast mode trip time plus 3 seconds/km margin recommended by korean standard LRT specification.

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Loading pattern design and economic evaluation for 24-month cycle operation of OPR-1000 in Korea

  • Jeongmin Lee;Hyun Chul Lee
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.1167-1180
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    • 2023
  • Due to the tightened regulatory environment since the Fukushima accident, the capacity factor of Korean nuclear power plants has been declining since 2011. To overcome this circumstance, a shift from 18-month to 24-month cycle operation is being considered in Korea. Therefore, in this study, loading patterns(LPs) for 24-month cycle operation of the Korean standard nuclear power plant(OPR-1000) are suggested and economic evaluations are performed. A single-zone LP with 89 fresh fuels was evaluated to be optimal for 24-month operation of OPR-1000 in terms of economic gain. The 24-month operation of OPR-1000 with this LP gives a profit of 7.073 million dollars per year compared to 18-month operation.

Design and Implementation of Simulator for Link-16 Network Operational Performance Analysis (Link-16 네트워크 운용성능분석을 위한 시뮬레이터 설계 및 구현)

  • Lee, Sangtae;Wi, Sounghyouk;Kim, Youngseung;Lee, Jungsik;Jee, Seungbae;Lee, Seungchan
    • Journal of the Korea Society for Simulation
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    • v.28 no.4
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    • pp.33-43
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    • 2019
  • Link-16 is a data link that provides joint interoperability to the US Navy, Air Force and NATO. Currently, the military relies entirely on foreign SW and tools for test environment, tactical simulation training and interoperability verification test for Link-16 operation. Therefore, it is necessary to develop Link-16 based operation environment test tool. In this paper, Link-16 network operational performance analysis simulator was developed by analyzing the function of Link-16 foreign tools. It also implements the SIMPLE standard interface for interworking with foreign SW and tools. The functional model for Link-16 network operation performance analysis consists of pre-analysis, real-time operational analysis, and post-analysis functional model. Each functional model test was performed through SIMPLE interworking with foreign SW and tools. Link-16 network operation performance analysis If we replace foreign SW through simulator, we can perform tactical training, network design verification and operation (scenario) verification for our military.

Development of Hybrid BMS(Battery Management System) Algorithm for Lead-acid and Lithium-ion battery (연축전지와 리튬이온전지용 하이브리드 BMS 알고리즘 개발)

  • Oh, Seung-Taek;Kim, Byung-Ki;Park, Jae-Beom;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.5
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    • pp.3391-3398
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    • 2015
  • Recently, the large scaled lead-acid battery is widely introduced to efficient operation of the photovoltaic system in many islands. but the demand of lithium-ion battery is getting increased by the operation of wind power and replacement of the lead-acid battery. And also, under the renewable portfolio standard(RPS) and energy efficiency resource standard(EERS) policy of Korea government, the introduction of energy storage system(ESS) has been actively increased. Therefore, this paper presents the operation algorithm of hybrid battery management system(BMS) using the lead-acid and lithium-ion batteries, in order to maximize advantage of each battery. In other words, this paper proposed the algorithm of state of charge(SOC) and hybrid operation algorithm to calculate the optimal composition rate considering the fixed cost and operation cost of each battery. From the simulation results, it is confirmed that the proposed algorithms are an effective tool to evaluate SOC and to optimally operate hybrid ESS.

A Study on the Relationship between Bus Operation Environment and Level of Service of Intra-City Bus - In the place of Ulsan Metropolitan Area - (시내버스 운행여건과 서비스 수준에 관한 연구 - 울산광역시 사례를 중심으로 -)

  • Kim, Beom-Ryong;Choi, Yang-Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.6
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    • pp.1309-1320
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    • 2015
  • This study made an attempt to analyse the relationship between operation environment and fleet size per route which represents the level of service for inner-city bus service. Regression analysis method has been adopted as main analysis tool and 98 routes of bus operation status in Ulsan city as of 2013 has also been selected for analysis target. Correlation analysis was performed to identify the relationship between dependent and independent variables. There are three types of model for whole sample, type operation, and bus route operation system. These are the results of the current study. 1. The model developed for whole sample of 98 routes is as follows. Y(Fleet Size)=$-4.532+0.00002877*X_1$(Revenue). This model shows that it is necessary to have more than 140 passengers per day to increase fleet size of each bus route in Ulsan. 2. Models developed by type of operation (which are standard, express, and middle sized) are shown below. Stand Bus : Y(Fleet Size)=$-10.954+0.00004283*X_1$(Revenue). It is identified that more than 153 passengers need to use standard bus to increase fleet size per each standard bus, Middle Sized Bus : Y(Fleet Size)=-0.859+0.00001438*X1(Revenue). For middle sized bus, at least 52 daily passengers are needed to increase number of bus in each route. 3. Models developed for each route operation systems are as belows. Joint Operation Group : Y(Fleet Size)=$-4.786+0.00003028*X_1$(Revenue). Individual Operation Group : Y(Fleet Size)=$-2.339+0.00002030*X_1$(Revenue). These model provide similar result which 140 people is the minimum number of passenger to raise the number of vehicles in each route. This result shows that the route operation systems does not affect the raise number of cars significantly.

A Suitability Analysis on the legal standards of the Rural Housing Standard Plans (농촌주택 표준설계도의 관련 법적 기준에의 적합성 분석 연구)

  • Jeon, Young-Hoon;Shin, Doo-Sik
    • Journal of the Korean Institute of Rural Architecture
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    • v.15 no.4
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    • pp.1-8
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    • 2013
  • The Rural Housing Standard Plans for improving the quality of life and housing stability in rural areas has been developed 87 types from 1994 to 2012. However, some types of Plans do not satisfy the current legal standard in accordance with social and legal changes. Standard plans has the same effect as a building permit, and replace it, so legal suitability of Plans is an important. Therefore, it is required the suitability analysis on the legal standards of Rural Housing Standard Plans. The Purpose of this study is to derive improper types and items of the Rural Housing Standard Plans on the legal standards. In this study, we analyzed its suitability on the legal standards(law on fire-fighting system installation and safety management, energy saving design criteria for buildings, structural checklist for small buildings, the types of drawing for building permit) in accordance with "rules for the operation of standard plans". And we analyzed the utilization of the Rural Housing Standard Plans through downloads from welchon portal.