• 제목/요약/키워드: Single Supply

검색결과 1,068건 처리시간 0.029초

The Integration Drive Equipment for Hoistby using Voltage Control Circuit (전압제어 회로에 의한 호이스트용 통합 드라이브 장치)

  • 라병훈;송대현;서기영;고희석;이현우
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 한국조명전기설비학회 2002년도 학술대회논문집
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    • pp.281-286
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    • 2002
  • An existent hoist drive system is using each different drive equipment in control of Hoisting, traveling(T/L), traversing(T/S) driving, so there are much energy losses because of excessive weight. Also, power circuits are using relay contact, so working environment are frequent secession accident etc.. by shock on unfavorable condition, and there is danger of safety accident, maintenance has frequent problem and so on. To solve these problem, it is integrated each driving power supply in drive system for hoist control and drive, utility power supply etc.. by single device in this research. The power circuit is consisted of non-contact circuit applying to bidirectional voltage controller circuit using thyristor that is power semiconductor switching device

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The Valuation of RFID Using Fuzzy Real Option (퍼지실물옵션을 이용한 RFID 투자가치평가)

  • Lee, Young-Chan;Lee, Seung-Seok
    • Knowledge Management Research
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    • 제9권4호
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    • pp.113-125
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    • 2008
  • Net present value (NPV) and return on investment (ROI) are commonly used to evaluate investment in new technologies. Sometimes, however, measuring the value of investment in new IT becomes very difficult due to its wide scope of application coupled with embedded options in its adoption. Therefore, comprehensive but easily understandable methodologies are needed to solve the complicated problems resulting from the complexity of new technologies. This paper employs a real option analysis to evaluate RFID adoption in the supply chain. Real options analysis should be a better way to evaluate a disruptive technology like RFID. However, the pure (probabilistic) real option rule characterizes the present value of expected cash flows and the expected costs by a single number, which is not realistic in many cases. To solve the problem, this paper considers the real option rule in a more realistic setting, namely, when the present values of expected cash flows and expected costs are estimated by trapezoidal fuzzy numbers.

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Dynamic Supplier-Managed Inventory Control and the Beneficial Effect of Information Sharing (공급자 주도의 동적 재고 통제와 정보 공유의 수혜적 효과 분석에 대한 연구)

  • Kim Eun-gab;Park Chan-kwon;Shin Ki-tae
    • Journal of the Korean Operations Research and Management Science Society
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    • 제29권3호
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    • pp.63-78
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    • 2004
  • This paper deals with a supplier-managed inventory(SMI) control for a two-echelon supply chain model with a service facility and a single supplier. The service facility is allocated to customers and provides a service using items of inventory that are purchased from the supplier, Assuming that the supplier knows the information of customer queue length as well as inventory position in the service facility at the time when it makes a replenishment decision, we identify an optimal replenishment policy which minimizes the total supply chain costs by reflecting these information into the replenishment decision. Numerical analysis demonstrates that the SMI strategy can be more cost-effective when the information of both customer queue length and inventory position is shared than when the information of inventory position only is shared.

Instantaneous Voltage Control of Inverter for Uninterruptible Power Supply (무정전전원장치용 인버터의 순시전압제어)

  • Kim, Jae-Sik;Kim, Wan-Ki;Kim, Hyo-Sung;Park, Se-Hyun;Choi, Jae-Ho
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1992년도 하계학술대회 논문집 B
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    • pp.1055-1059
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    • 1992
  • Instantaneous Voltage Control of inverter for uninterruptible power supply(UPS) is presented. In order to improve the transient response, the authors propose a control scheme based on a double regulation loop with sinusoidal hysteresis band. And also, using 8097 single chip microprocessor, software synchronization and static switch control scheme is impremented with minimal hard ware structure.

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The Comparison of Reliability for Change Single Loop Configuration in Radial Power Distribution System (수지상 배전계통을 단일루프로 구조 변경시 신뢰도 비교)

  • Lee, Hee-Tae;Kim, Jae-Chul;Kim, Ju-Yong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • 제58권8호
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    • pp.1472-1478
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    • 2009
  • The domestic power distribution system is operating in an open loop mode; however, it already has a loop structure. Power distribution systems must be changed for bi-directions power supply for smart networks due to a changing of paradigm in electric power industry. The simplest bi-directions distribution networks can make it closing of normally open switch. However, bi-directions power supply is very difficulty to be operated and there are many parts which it must study. This paper presented various models that are able to change a radial system for loop structures. Further, we compared the reliability index for each model by evaluating the amount of improvement reliability required in radial power distribution system. In addition, we calculated CIC(Customer Interruption Cost) for each model by comparing and analyzing.

A Status of Power Supply Technology for High Intensity LED (고휘도 LED 램프의 전원기술 동향)

  • Han Soo-Bin;Jung Hak-Kun;Jung Bong-Man;Park Suck-In;You Song-Won
    • Proceedings of the KIPE Conference
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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    • pp.906-909
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    • 2004
  • Status of high intensity LED, one of the recent issue in industry is reviewed. In a system view, various power supply methods for multiple array construction are introduced rather than one for single LED. Custom IC for driving LED and different circuit for applications are also considered.

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Low power-high performance embedded SRAM circuit techniques with enhanced array ground potential (어레이 접지전압 조정에 의한 저전력, 고성능 내장형 SRAM 회로 기술)

  • 정경아;손일헌
    • Journal of the Korean Institute of Telematics and Electronics C
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    • 제35C권2호
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    • pp.36-47
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    • 1998
  • Low power circuit techniques have been developed to realize the highest possible performance of embedded SRAM at 1V power supply with$0.5\mu\textrm{m}$ single threshold CMOS technology in which the unbalance between NMOS and PMOS threshold voltages is utilized to optimize the low power CMOS IC design. To achieve the best trade-off between the transistor drivability and the subthreshold current increase, the ground potential of memory array is raised to suppressthe subthreshold current. The problems of lower cellstability and bit-line dealy increase due to the enhanced array ground potential are evaluated to be controlled within the allowable range by careful circuit design. 160MHz, 128kb embedded SRAM with 3.4ns access time is demonstrated with the power consumption of 14.8mW in active $21.4{mu}W$ in standby mode at 1V power supply.

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A Wide Range PLL for 64X CD-ROMs & l0X DVD-ROMs (64배속 CD-ROM 및 10배속 DVD-ROM용 광대역 위상 고정 루프)

  • 진우강;이재신;최동명;이건상;김석기
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 1999년도 추계종합학술대회 논문집
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    • pp.340-343
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    • 1999
  • In this paper, we propose a wide range PLL(Phase Locked Loop) for 64X CD-ROMs & l0X DVD-ROMs. The frequency locking range of the Proposed PLL is 75MHz~370MHz. To reduce jitters caused by large VCO gain and supply voltage noise, a new V-I converter and a differential delay cell are used in 3-stage ring VCO, respectively. The new V-I converter has a 0.6V ~ 2.5V wide input range. In addition, we propose a new charge pump which has perfect current matching characteristics for the sourcing/sinking current. This new charge pump improves the locking time and the locking range of the PLL. This Chip is implemented in 0.25${\mu}{\textrm}{m}$ CMOS process. It consumes 55㎽ in worst case with a single 2.5V power supply.

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A Low Voltage, Digital Automatic Gain Controller (비디오 시스템을 위한 저전압, 디지털 자동이득 조절기)

  • 권진호
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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    • pp.183-186
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    • 2000
  • In this paper we propose a new architecture of a programmable digital automatic gain controller(AGC) for analog interface in mixed mode systems. Compared with conventional analog AGCs which have difficulties in integration due to large capacitors, the proposed AGC is easily integrated. So the production cost can be reduced. In addition, The proposed AGC has a better performance in temperature, and power supply variations, and substrate noise than analog counterparts do. To prevent erroneous operations of the AGC due to noise, a mal-function preventer is newly proposed. In addition, to achieve an optimized AGC time constant, we propose a logic block which controls an up-down counting clock. This is directly related to the changing speed of the AGC gain. Implemented with a 0.25 $\mu\textrm{m}$ 1-poly, 5-metal CMOS parameters, the AGC operates from a single 2.5V power supply with the dynamic range of 36.ldB and occupies active area of 500$\mu\textrm{m}$${\times}$600$\mu\textrm{m}$

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Development of Short-circuit Testing Facility for Distribution Transformers (배전용 변압기 단락강도 시험설비 개발)

  • Park, Ji-Hun;Min, Yun-Hong;Kang, Young-Hak;You, Ho-Keun;Ahn, Kyu-Sun;Ham, Gil-Ho;Oh, Chang-Ju
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.64-67
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    • 2002
  • To increase the short-circuit testing capacity of distribution transformers, testing facility has been installed for KEPCO in Vi-wang. The power supply of testing facility is directly supplied from the network substation located closely. Testing can be performed up to 300 kVA for single-phase transformers, 500 kVA for three-phase transformers. Operating with this facility, the distribution company is able to maintain the reliable supply of electricity. Also the critical quality of transformers from manufacturers can be verified by short-circuit testing. This paper describes the design concept and specification of newly developed equipment and the procedure of short-circuit test.

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