• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.94-96
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• 1997

A mathematical model (hybrid arc model) for arc behaviour in an $SF_6$ puffer gas-blast circuit-breaker has been developed. It has adopted the advantages of integral method and differential method. The method has been applied to model puffer circuit breaker of Noeske et al and good agreement of critical RRRV(Ratio of Rise of Recovery Voltage) has been obtained. Axial or radial distributions of temperature, electric field and arc radius are also presented and analyzed.

• Journal of the Microelectronics and Packaging Society
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• v.4 no.2
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• pp.1-16
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• 1997

Modern electronic components require its sophistication to meet the stringent requirements which are demanded for high tech industry. In an attempt to meet to such demand miniaturization of the components has been considrably progressed to increase its circuit density. High density of the components can be achieved by an innovative technology of design and manufacturing with functionally improved or new materials such as small bulk devices thick films and thin films circuits (2D). Recently many efforts have been extensively made in the community of the Hybrid Microelectronics through out world. In this paper an approach is introduced in realizing a sophisticated passive circuit for the microelectronics applications by use of hybrid thick/thin films technology. The merit of this technology is discussed and the future trend is speculated.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.321-322
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• 2015

The aim of this paper is to propose a design method for the double-sided LCC compensation circuit for 6.6kW electric vehicle (EVs) wireless charger. The analysis and comparison with several compensation topologies such as SS, SP, PS, PP and the hybrid LCC compensation is presented. It has been found that the hybrid LCC compensation has superior performance in comparison with other topologies. The design procedure for the EV charger is presented and the PSIM simulation results are provided.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.131-133
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• 2001

2D analysis is impossible for Hybrid stepping motor(HSM) and 3D analysis is necessary because the permanent magnet is magnetized to the axial direction. In this paper, the characteristics of HSM are analyzed by using 3D equivalent magnetic circuit network method(3D EMCNM). In addition, the trapezoidal element is introduced for the exact permeance calculation in the complex shape machinery such as HSM. The magnetic saturation of core is considered.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.631-640
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• 2016

A dual-mode power management for a hybrid-electric UAV with a cruise power of 200W is proposed and empirically verified. The subject vehicle is a low-speed long-endurance UAV powered by a solar cell, a fuel cell, and a battery pack, which operate in the same voltage bounds. These power sources of different operational characteristics can be managed in two different methods: passive management and active management. This study proposes a new power management system named PMS2, which employs a bypass circuit to control the individual power sources. The PMS2 normally operates in active mode, and the bypass circuit converts the system into passive mode when necessary. The output characteristics of the hybrid system with the PMS2 are investigated under simulated failures in the power sources and the conversion of the power management methods. The investigation also provides quantitative comparisons of efficiencies of the system under the two distinct power management modes. In the case of the solar cell, the efficiency difference between the active and the passive management is shown to be 0.34% when the SOC of the battery is between 25-65%. However, if the SOC is out of this given range, i.e. when the SOC is at 90%, using active management displays an improved efficiency of 6.9%. In the case of the fuel cell, the efficiency of 55% is shown for both active and passive managements, indicating negligible differences.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.1
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• pp.1-9
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• 2012

A 10-b 500 MS/s A/D converter (ADC) with a hybrid calibration and error correction logic is described. The ADC employs a single-channel cascaded folding-interpolating architecture whose folding rate (FR) is 25 and interpolation rate (IR) is 8. To overcome the disadvantage of an offset error, we propose a hybrid self-calibration circuit at the open-loop amplifier. Further, a novel prevision digital error correction logic (DCL) for the folding ADC is also proposed. The ADC prototype using a 130 nm 1P6M CMOS has a DNL of ${\pm}0.8$ LSB and an INL of ${\pm}1.0$ LSB. The measured SNDR is 52.34-dB and SFDR is 62.04-dBc when the input frequency is 78.15 MHz at 500 MS/s conversion rate. The SNDR of the ADC is 7-dB higher than the same circuit without the proposed calibration. The effective chip area is $1.55mm^2$, and the power dissipates 300 mW including peripheral circuits, at a 1.2/1.5 V power supply.

• Journal of Welding and Joining
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• v.13 no.3
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• pp.55-64
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• 1995

Metallizing method on ceramic surface is one of the compositing technology of ceramics and metal. The purpose of this study is to make HIC (Hybrid Intergrated Circuit) with copper metallizing method of which copper layer is formed on ceramic substrate by firing in atmosphere in lieu of conventional hybrid microcircuit systems based on noble metal. Metallizing pastes were made from various copper compounds such as Cu$_{2}$O, CuO, Cu, CuS and kaolin. And the screen printing method was used. The characteristics of metallized copper layers were analyzed through the measurement of sheet resistance, SEM, and EDZX. The results obtainted are summarized as follows; 1. The copper metallizing layers on ceramic surface can be formed by firing in air. 2. The metallized layer using Cu$_{2}$O paste showed the smallest sheet resistance among a group of copper chemical compounds. And optimum metallizing conditions are 15 minutes of firing time, 1000.deg.C of firig temperature, and 3 minutes of deoxidation time. 3. The results of EDAX analysis showed mutual diffusion of Cu and Al. 4. The kaolin plays a important role of deepening the penetration of Cu to $Al_{2}$O$_{3}$ ceramics. But if the kaolin content is too much, sheet resistance increases and copper metallizing layer becomes brittle.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1873-1875
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• 1996

This paper deals with the lightning surge protective devices with combination of varistor and LC filter. UP to now, the varistor alone were used as overvoltage protection devices fer the AC power mains. In this work, in order to improve the cutoff performance of surge protective device, the hybrid circuit surge protective device for an AC single phase mains was designed and investigated. The first stage of hybrid circuit is to remove most of any large surge energy and protect the second stage components. The purpose of the second is to protect the load and increase the cutoff capacity of surge protective devices. Also LC filter attenuates the remnant that travels downstream from the first stage component and the high frequency noises. As a consequence, it was found that the proposed hybrid surge protective device for AC power mains has a variety of advantages such as low and tight clamping voltage, high frequency noise reduction and large cutoff capacity.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.5
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• pp.51-60
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• 2004

Due to the improvements in circuit design and manufacturing technique, the complexity of a circuit is growing. Since the complexity of a circuit causes high frequency of faults, it is very important to locate faults for improvement of yield and reduction of production cost. But unfortunately it takes a long time to find sites of defects by e-beam proving if the physical level. A fault diagnosis algorithm in the Sate level has meaning to reduce diagnosis time by limiting fault sites. In this paper, we propose an efficient fault diagnosis algorithm in the logical level. Our method is hybrid fault diagnosis algorithm using a new fault dictionary and additional fault simulation which minimizes memory consumption and simulation time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1076-1081
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• 2007

In this paper, we propose a new switch structure for time division duplex(TDD) system. The existing TDD structure utilizes a circulator fur isolation characteristic between ports. However, the circulator produces intermodulation distortion signals which are undesired signal because of its nonlinear properties. The proposed circuit is composed of a modified branch-line hybrid coupler which controls the signal flow while the isolated port is open-/short- terminated. In order to prove the validity of the presented structure, the switch circuit is fabricated and measured at 2.3GHz, the center frequency of Wibro service system.