• Proceedings of the IEEK Conference
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• 2000.06c
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• pp.169-172
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• 2000

IP Switching is a new routing technology proposed to improve the performance of IP routers. Flow classification is one of the key issues in IP Switching. To achieve better performance, flow classification should be matched to the varying IP traffic and an IP switch should make use of its hardware switching resources as fully as possible. This paper proposes an adaptive flow classification algorithm for IP Switching. By dynamically adjusting the values of its control parameters in response to the present usage of the hardware switching resources, this adaptive algorithm can efficiently match the varying IP traffic and thus improve the performance of an IP switch.

• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.123-134
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• 1991

one of the problems the users of DPS-6/45 used to face in the course of having access to work stations was that a telephone call has to be made manually every time to have receiver's modem on or off, and naturally it meant the waste of manpower as well as of time. A program has been worked out to automatically operate and control. utilizing the system clock within the main computer (DPS-6/45), the on/off switch on the modems. It has resulted in; 1) promotion in operability of the main computer, DPS-6/45 2) prevention of unnecessary telephone calls 3) curtailment of expenditure and manpower

• Journal of Power Electronics
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• v.18 no.4
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• pp.955-964
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• 2018

In this paper, an active capacitor-diode-switch (CDS) snubber is proposed for L-type current-fed isolated DC-DC converters. The proposed CDS-clamped converter has a number of advantages. It can achieve wide range zero-voltage switching (ZVS) on two switches, a continuous input current with a low ripple, a reduction of one active switch and high efficiency. The operating principles, analysis and parameter design guideline are presented. A 300 W prototype is built to test the proposed converter. Simulation and experimental results are shown at 30 V input voltage and 400 V output voltage.

• Progress in Superconductivity
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• v.5 no.1
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• pp.21-25
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• 2003

We have designed and simulated an 1-bit ALU (Arithmetic Logic Unit) by using a half adder. An ALU is the part of a computer processor that carries out arithmetic and logic operations on the operands in computer instruction words. The designed ALU had limited operation functions of OR, AND, XOR, and ADD. It had a pipeline structure. We constructed an 1-bit ALU by using only one half adder and three control switches. We designed the control switches in two ways, dc switch and NDRO (Non Destructive Read Out) switch. We used dc switches because they were simple to use. NDRO pulse switches were used because they can be easily controlled by control signals of SET and RESET and show fast response time. The simulation results showed that designed circuits operate correctly and the circuit minimum margins were ＋/-27%. In this work, we used simulation tools of XIC and WRSPICE. The circuit layouts were also performed. The circuits are being fabricated.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.1
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• pp.22-30
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• 2002

ln this paper, it was reported the developed results of the monitoring unit for 72.5kY GIS which it is one part of the monitoring system for the substation that Korea Railway Company is promoting. In order to monitor the operational status of GIS, four parameters were chosen: the number of times of the circuit breaker switching, tightness of the gas-sealed units (circuit breaker / disconnecting switch / earthing switch), the number of times of the lightning arrestor operating and the leakage current of the lighting arrester. We constructed the monitoring system that can be judged the operating condition of the GIS from the signal of the suitable sensor for the purpose. Therefore, it is possible to on line monitoring for the condition of the GlS without efforts of the Periodic inspection.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.295-298
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• 1999

In this paper, the diode bridge-type ZVT(Zero-Voltage Transition) inverter is proposed. It consists of one auxiliary switch, three resonant inductors and six blocking diodes. So, the advantage of the proposed topology is the reduction of the auxiliary switch. The topology of the proposed ZVT inverter is analyzed with a description of the control conditions based on the load current. Therefore, this paper two control algorithms were discussed. A variable resonant pattern control algorithm by using load current feedback and a resonant period control algorithm by using resonant inductor current feedback is proposed in order to achieve the ZVT switching condition in full control range and the reducing current spike main switches cause by reverse recovery problem.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.54 no.4
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• pp.171-178
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• 2005

The proposed dual-output DC-DC converter that bases on flyback converter can obtain two output voltage with non-isolated main-output and isolated sub-output at the same time using single-winding high frequency transformer. It can solve problems in multi-winding converter that use one main-switch, and also control quality of isolated sub-output voltage can be improved by additional sub-switch to the second. For analysis and design of the proposed converter system, converters are classified as operation mode from switching state and are become modeling by applying state space averaging method. Steady-state characteristics and dynamic characteristics are analyzed by DC component and perturbation component from state space averaging model. From experiment converter, validity of analysis and design for the propose converter system is confirm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.268-275
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• 2015

This paper proposes a method of switching to improve power loss for the single-phase three-level NPC inverter. The conventional switching methods, which are called as the bipolar and unipolar switching methods, are used for single phase inverters using three-level topology. However, these switching method have disadvantage in the power loss. Because all of the switch are operated. To reduce the power loss of the three-level NPC inverter, clamp switching method is introduced in this paper. This way, one of the lag is fixed that switching loss is reduced. This paper analyzes and compares power losses of unipolar method and clamp method. The validity of the power loss analysis is verified through the simulation and experimental results.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.82-87
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• 1999

The Asynchronous Transfer Mode(ATM) networks are being adopted as backbones over various parts of Internet. TCP is one of the most widespread transport protocols and can be used with ATM. But, TCP shows poor end-to-end performance on ATM networks. Effective throughput of TCP over ATM can be quite low when cells are dropped at the congested ATM switch. As congested link transmits cells from corrupted packets, it wastes bandwidth and throughput becomes low. This paper examines the behavior of TCP over ATM-UBR using EPD switch in a broadband environment. As threshold value closes to the buffer size, the buffer can be used more efficiently, but more drops and retransmission occur. If the threshold value is much less than buffer size, efficiency becomes low, but few drops can be happen. Therefore, the decision of threshold value becomes important factor.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.3
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• pp.136-145
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• 2006

Two major processing technologies of GaAs HBT and pHEMT have been released in production at Win Semiconductors corp. to address the strong demands of power amplifiers and switches for both handset and WLAN communications markets. Excellent performance with low processing cost and die shrinkage features is reported from the manufactured MMICs. With the stringent tighter manufacturing quality control WIN has successfully become one of the major pure open foundry house to serve the communication industries. The advancing of both technologies to include E/D-pHEMTs and BiHEMTs likes for multifunctional integration of PA, LNA, switch and logics is also highlighted.