• Title/Summary/Keyword: switch

Search Result 4,295, Processing Time 0.092 seconds

Discrete-Time Queuing Analysis of Dual-Plane ATM Switch with Synchronous Connection Control

  • Choi, Jun-Kyun
    • ETRI Journal
    • /
    • v.19 no.4
    • /
    • pp.326-343
    • /
    • 1997
  • In this paper, we propose an ATM switch with the rate more than gigabits per second to cope with future broadband service environments. The basic idea is to separate the connection control flow from the data information flow inside the switch. The proposed switch has a dual-plane switch matrix with the synchronous control algorithm. The queuing behaviors of the proposed switch are shown by the discrete-time queuing analysis. Numerical analyses are taken both in the non-blocking crossbar switch and the banyan switch with internal blocking. Results show that a proposed dual-plane $16{\times}16$ switch would have the acceptable performance with maximum throughput of about 95 percent.

  • PDF

Circuit Design of an RSFQ 2$\times$2 Crossbar Switch for Optical Network Switch Applications (광 네트워크 응용을 위한 RSFQ 2$\times$2 Switch 회로의 설계)

  • 홍희송;정구락;박종혁;임해용;강준희;한택상
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
    • /
    • 2003.10a
    • /
    • pp.146-149
    • /
    • 2003
  • In this Work, we have studied about an RSFQ 2$\times$2 crossbar switch. The circuit was designed, simulated, and laid out for mask fabrication The switch cell was composed of a splitter a confluence buffer, and a switch core. An RSFQ 2$\times$2 crossbar switch was composed of 4 switch cells, a switch control input to select the cross and bar, data input, and data outputs. When a pulse was input to the switch control input to select the cross or bar the route of the input data was determined, and the data was output at the proper output port. We simulated and optimized the switch-element circuit and 2$\times$2 crossbar switch, by using Xic and Julia. We also performed the mask layout of the circuit by using Xic and Lmeter.

  • PDF

PROLONG THE SERVICE LIFE OF SWITCH RAIL BY IMPROVED INDUCTION HEAT TREATMENT

  • Zhan, Xinwei;Wang, Shuqing
    • Proceedings of the KSR Conference
    • /
    • 2007.11a
    • /
    • pp.1946-1950
    • /
    • 2007
  • Switch rail is a very important part on the railway track, which not only accounts for the safety of the passing trains but also greatly influences the speed of the train. The higher the speed and the loads of the train the more it demands on the properties of the switch rail. Research shows that the higher mechanical properties of switch rail the longer the service life. Induction heat treatment is a good way of improving the mechanical properties of metallic materials. But the switch rail's section area changes gradually across the lengthways, which is difficult for induction heating especially for the small section. And the mechanical property of small section of the switch rail is the most important for its service life. The induction heat treatment used past always brings the low hardness on small section which can cause low service life of switch for wearing, or too high hardness because of martensite microstructure which can cause the shelling or even breaking of the switch rail. To prolong the service life of switch rail by higher mechanical properties, we researched the improved induction heat treatment for switch rail by adjusting speed of heating, and adopting compressed air cooling. The results showed that switch rail obtain almost the same high hardness across the length way after the improved induction heat treatment, which is very helpful to extend the service life of switch rail.

  • PDF

Development of a Piecewise Bendable Switch System for the Urban Transit MagLev(I) (도시형 자기부상열차용 굴절형 분기장치의 개발(I))

  • Lee, Jong-Min;Jo, Heung-Je;Kim, In-Geun
    • 연구논문집
    • /
    • s.29
    • /
    • pp.57-67
    • /
    • 1999
  • This paper presents the status quo of the development of a piecewise bendable switch system for the urban transit MagLev. MagLev system as well as railroad requires switch systems to reach its destination. Requirements of the switch system for commercial lines are high speed operation satisfying about 2-3 minute headway and system reliability, etc. Parallel moving type switch system was installed on the test track of urban transit MagLev in KIMM. In this system, switch operation from one position to another can be done in about 90 seconds. Therefore, we concluded that this system can not satisfy the headway for the commercial lines. We decided to develop a high speed piecewise bendable switch system in which switching can be done in 20 seconds. Designed switch system is very complicated in view of operating mechanism. It consists of 11 segmented girder beams driven by hydraulic cylinders. To gain the idea of a piecewise bendable switch system, we manufactured and tested a 1/5 scale switch model. We are going to construct a full scale piecewise bendable switch system next year.

  • PDF

Advanced Three-Phase PFC Power Converters with Three-Phase Diode Rectifier and Four-Switch Boost Chopper

  • Nishimura Kazunori;Hirachi Katsuya;Hiraki Eiji;Ahmed Nabil A.;Lee Hyun-Woo;Nakaoka Mutsuo
    • Journal of Power Electronics
    • /
    • v.6 no.4
    • /
    • pp.356-365
    • /
    • 2006
  • This paper presents an improved three-phase PFC power rectifier with a three-phase diode rectifier cascaded four-switch boost converter. Its operating principle contains the operating principle of two conventional three-phase PFC power rectifiers: one switch boost converter type and a two switch boost converter type. The operating characteristics of the four switch boost converter type three-phase PFC power rectifier are evaluated from a practical point of view, being compared with one switch boost converter type and two switch boost converter topologies.

A Cognitive Evaluation of Hand Switch Layouts in the Main Control Board of Nuclear Power Plants (원자력 발전소 주 제어반의 제어 스위치 배치에 대한 인지적 수행도 평가)

  • Byun, Seong-Nam;Lee, Dong-Hoon
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.26 no.2
    • /
    • pp.136-145
    • /
    • 2000
  • The objective of this study is to evaluate the human performance relating to the layouts of the two different hand switch types with two and three buttons in the nuclear power plants. Using a computer simulation, the cognitive performance for the hand switch layouts was measured on the basis of response and task completion times. Comparative analyses were performed with three different layouts representing the current switch arrangements in the Yonggwang nuclear plants 5 and 6 and Ulchin 3 and 4, respectively. Statistical analyses revealed that the performance of the two-buttoned switch layouts was found to be better than those of the three-buttoned switch. Furthermore, the superiority of the two-buttoned switch type is consistent regardless of various layout types. These results imply that the difference of the cognitive performance can be attributable to the switch types rather than to the switch layouts. Therefore, from the cognitive perspective, the two-buttoned switch type is recommended for future power nuclear plants.

  • PDF

Structure and Implementation of Fully Interconnected ATM Switch (Part II : About the implementation of ASIC for Switching Element and Interconnected Network of Switch) (완전 결합형 ATM 스위치 구조 및 구현 (II부 스위치 엘리먼트 ASIC화 및 스위치 네트워크 구현에 대하여))

  • 김경수;김근배;박영호;김협종
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.1
    • /
    • pp.131-143
    • /
    • 1996
  • In this paper, we propose the improved structure of fully interconnected ATM Switch to develop the small sized switch element and represent practical implementation of switch network. As the part II of the full study about structure and implementation of fully interconnected ATM Switch, this paper especially describes the implementation of an ATM switching element with 8 input port and 8 output port at 155 Mbits/sec each. The single board switching element is used as a basic switching block in a small sized ATm switch for ATM LAN Hub and customer access node. This switch has dedicated bus in 12 bit width(8 bit data + 4 bit control signal) at each input and output port, bit addressing and cell filtering scheme. In this paper, we propose a practical switch architecture with fully interconnected buses to implement a small-sized switch and to provide multicast function withoutany difficulty. The design of switching element has become feasible using advanced CMOS technology and Embedded Gate Array technology. And, we also represent Application Specific Integrated Circuit(ASIC) of Switch Output Multiplexing Unit(SOMU) and 12 layered Printed Circuit Board for interconnection network of switch.

  • PDF

ASYMPTOTIC MAXIMUM PACKET SWITCH THROUGHPUT UNDER NONUNIFORM TRAFFIC

  • JEONG-HUN PARK
    • Management Science and Financial Engineering
    • /
    • v.4 no.2
    • /
    • pp.43-58
    • /
    • 1998
  • Packet switch is a key component in high speed digital networks. This paper investigates congestion phenomena in the packet switching with input buffers. For large value of switch size N, mathematical models have been developed to analyze asymptotic maximum switch throughput under nonuniform traffic. Simulation study has also been done for small values of finite N. The rapid convergence of the switch performance with finite switch size to asymptotic solutions implies that asymptotic analytical solutions approximate very closely to maximum throughputs for reasonably large but finite N. Numerical examples show that non-uniformity in traffic pattern could result in serious degradation in packet switch performance, while the maximum switch throughput is 0.586 when the traffic load is uniform over the output trunks. Window scheduling policy seems to work only when the traffic is relatively uniformly distributed. As traffic non-uniformity increases, the effect of window size on throughput is getting mediocre.

  • PDF

A Study on New Inverse Pinch Switch for High Power Transfer (High Power 전달을 위한 새로운 Inverse Pinch Switch에 관한 연구)

  • Cho, Kook-Hee;Kim, Young-Bae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.20 no.10
    • /
    • pp.120-125
    • /
    • 2006
  • In contrast to the conventional trigatron switch in which the currents are constricted by the z-pinch mechanical the new switch operates in an inverse pinch geometry formed by a pair of spiral electrodes in a sealed-off type. Inverse pinch switch greatly reduces hot spot formations and protects the electrode surfaces. The switch can be initiated with an electrical trigger electrode. Advantages of the new switch over the conventional switches are longer useful life, high current capability and lower inductance due to the dispersed and moving current sheet. These improved characteristics may make the inverse pinch switch suitable for pulse power systems.

Improved Zero-Current-Switching(ZCS) PWM Switch Cell with Minimum Additional Conduction Losses

  • Park, Hang-Seok;Cho, B.H.
    • Journal of Power Electronics
    • /
    • v.1 no.2
    • /
    • pp.71-77
    • /
    • 2001
  • This paper proposes a new zero-current switching (ZCS) pulse-width modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero current condition. The diodes commutate softly and the reverse recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of DC to DC PWM converters is derived. The new family of ZCS PWM converters is suitable for the high power applications employing IGBTs. Among the new family of DC to DB PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5 kW prototype converter operating at 40 kHz.

  • PDF