• Title/Summary/Keyword: Passive operation.

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Development of the Hybrid EMI Filter for DC-DC Converter (DC-DC 전력변환장치용 Hybrid EMI 필터 개발)

  • Lee, Dong-Ho;Yoo, Jin-Wan;Park, Chong-Yeun
    • Journal of Industrial Technology
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    • v.34
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    • pp.71-78
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    • 2014
  • Recently, using the electronic devices was increased with semiconductor developments. So, the EMI(Electromagnetic interference) problem become to important issue for coexistence with each electronic devices. The EMI is caused by switching operation from the power switches as the FET and the transistor in power conversion devices. In this paper, the hybrid EMI filter that composed with active components and passive components was described. The EMI filter is applied to the 160 watts LED driver experimentally verify the performance. The hybrid EMI filter is compared with non-filter, only passive filter and only active filter. The proposed EMI filter attenuated CM noise more than traditional passive filter.

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Review on the Optical tin]k Technologies for the Gigabit-per-second Wavelength-Division-Multiplexing Passive Optical Networks (WDM-PONs) (기가급 WDM-PON을 위한 광기술 분석)

  • Park Tae-Sang;Park Kun-Youl;Kim Jin-Hee;Yoon Ho-Sung
    • 한국정보통신설비학회:학술대회논문집
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    • 2006.08a
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    • pp.11-14
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    • 2006
  • This paper reviews the optical link technologies which have been developed for gigabit-per-second wavelength-division-multiplexing passive optical networks (WDM-PONs). Similarly to the 100Mb/s WDM-PON systems which have been deployed for trial services by KT, the most important requirement for 1Gb/s WDM-PON is wavelength independence (colorless feature) of its ONU/ONTs, which makes possible convenient operation and cost-effective maintenance with minimum inventory cost. Among various methods to implement such colorless feature, four promising candidates for gigabit WDM-PON are analyzed with their own development issues and their expected performances are compared.

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Design of miniaturized active 90$^{\circ}$ phase divider on RFIC/MMIC for application to maritime wireless communication components (해상 무선통신소자의 응용을 위한 RFIC/MMIC용 소형화된 능동형 90$^{\circ}$ 위상 분배기의 설계)

  • Park, Young-Bae;Yun, Young
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.406-411
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    • 2005
  • In this paper, we propose an active 90$^{\circ}$ phase divider for application to MMIC. Because of their very large size, conventional passive 90$^{\circ}$ dividers can't be integrated on MMIC. Therefore, highly miniaturized 90$^{\circ}$ dividers are required for a development of highly integrated MMIC. For this reason, active 90$^{\circ}$ divider is indispensable because active phase divider is much smaller than conventional passive dividers, and it can be integrated on MMIC. In this work, we developed active 90$^{\circ}$ divider with emitter inductor, and it was employed for the operation of the balanced mixer in order to verify the performance of the active 90$^{\circ}$ divider. According to the results, it was found that the active 90$^{\circ}$ divider exhibited good RF performances comparable to conventional passive power dividers.

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Design and Implementation of a RFID Transponder Chip using CMOS Process (CMOS 공정을 이용한 무선인식 송수신 집적회로의 설계 및 제작)

  • 신봉조;박근형
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.10
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    • pp.881-886
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    • 2003
  • This paper describes the design and implementation of a passive transponder chip for RFID applications. Passive transponders do not have their own power supply, and therefore all power required for the operation of a passive transponder must be drawn from the field of the reader. The designed transponder consists of a full wave rectifier to generate a dc supply voltage, a 128-bit mask ROM to store the information, and Manchester coding and load modulation circuits to be used for transmitting the information from the transponder to the reader. The transponder with a size 410 x 900 ${\mu}$m$^2$ has been fabricated using 0.65 ${\mu}$m 2-poly, 2-metal CMOS process. The measurement results show the data transmission rate of 3.9 kbps at RF frequency 125 kHz.

A Stability Effect of Passive Compliance on Active Compliance Control (수동 Compliance가 능동적 Compliance제어의 안정도에 미치는 영향)

  • Chung, Tae-Sang
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.1
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    • pp.92-106
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    • 1990
  • Active compliance is often used in the control of robot manipulators for the implementation of complex tasks such as assembly, multi-finger fine motion, legged-vehicle adaptive control,etc. This technique balances the interactive force between the manipulator tip and its working environment with its position and velocity errors to achieve the operation of a damped spring. This paper investigates the effecft of passive compliance on system stability with regard to force feedback implementation for actively compliant motion. Usually it is understood that accurate position control require a stiff system. However, theoretical examination of control experiments on a legged suspension vehicle suggests that, if the control includes discrete-time force feedback, some passive compliance is necessssary at the legs of the vehicle for system stability. This can be an important factor to bl considered in manipulator design and control. A theoretical analysis, numerical simulation, and experimental result, confirming the above conclusion, are introduced in this paper.

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Passive parasitic UWB antenna capable of switched beam-forming in the WLAN frequency band using an optimal reactance load algorithm

  • Lee, Jung-Nam;Lee, Yong-Ho;Lee, Kwang-Chun;Kim, Tae Joong
    • ETRI Journal
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    • v.41 no.6
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    • pp.715-730
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    • 2019
  • We propose a switched beam-forming antenna that satisfies not only ultra-wideband characteristics but also beam-forming in the WLAN frequency band using an ultra-wideband antenna and passive parasitic elements applying a broadband optimal reactance load algorithm. We design a power and phase estimation function and an error correction function by re-analyzing and normalizing all the components of the parasitic array using control system engineering. The proposed antenna is compared with an antenna with a pin diode and reactance load value, respectively. The pin diode is located between the passive parasitic elements and ground plane. An antenna beam can be formed in eight directions according to the pin diode ON (reflector)/OFF (director) state. The antenna with a reactance load value achieves a better VSWR and gain than the antenna with a pin diode. We confirm that a beam is formed in eight directions owing to the RF switch operation, and the measured peak gain is 7 dBi at 2.45 GHz and 10 dBi at 5.8 GHz.

Comparisons of performance and operation characteristics for closed- and open-loop passive containment cooling system design

  • Bang, Jungjin;Jerng, Dong-Wook;Kim, Hangon
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2499-2508
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    • 2021
  • Passive containment cooling systems (PCCSs) have been actively studied to improve the inherent safety of nuclear power plants. Hered, we present two concepts, open-loop PCCS (OL-PCCS) and closed-loop PCCS (CL-PCCS), applicable to the PWR with a concrete-type containment. We analyzed the heat-removal performance and flow instability of these PCCS concepts using the GOTHIC code. In both cases, PCCS performance improved when a passive containment cooling heat exchanger (PCCX) was installed in the lower part of the containment building. The OL-PCCS was found to be superior in terms of heat-removal performance. However, in terms of flow instability, the OL-PCCS was more vulnerable than the CL-PCCS. In particular, the possibility of flow instability was higher when the PCCX was installed in the upper part of the containment. Therefore, the installation location of the OL-PCCS should be restricted to minimize flow instability. Conversely, a CL-PCCS can be installed without any positional restriction by adjusting the initial system pressure within the loop, which eliminates flow instability. These results could be used as base data for the thermo-hydraulic evaluation of PCCS in PWR with a large dry concrete-type containment.

Integral effect tests for intermediate and small break loss-of-coolant accidents with passive emergency core cooling system

  • Byoung-Uhn Bae;Seok Cho;Jae Bong Lee;Yu-Sun Park;Jongrok Kim;Kyoung-Ho Kang
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2438-2446
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    • 2023
  • To cool down a nuclear reactor core and prevent the fuel damage without a pump-driven active component during any anticipated accident, the passive emergency core cooling system (PECCS) was designed and adopted in an advanced light water reactor, i-POWER. In this study, for a validation of the cooling capability of PECCS, thermal-hydraulic integral effect tests were performed with the ATLAS facility by simulating intermediate and small break loss-of-coolant accidents (IBLOCA and SBLOCA). The test result showed that PECCS could effectively depressurize the reactor coolant system by supplying the safety injection water from the safety injection tanks (SITs). The result pointed out that the safety injection from IRWST should have been activated earlier to inhibit the excessive core heat-up. The sequence of the PECCS injection and the major thermal hydraulic transient during the SBLOCA transient was similar to the result of the IBLOCA test with the equivalent PECCS condition. The test data can be used to evaluate the capability of thermal hydraulic safety analysis codes in predicting IBLOCA and SBLOCA transients under an operation of passive safety system.

Comparison on Safety Features among HTGR's Reactor Cavity Cooling Systems (RCCSs)

  • Kuniyoshi Takamatsu;Shumpei Funatani
    • Nuclear Engineering and Technology
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    • v.56 no.3
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    • pp.832-845
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    • 2024
  • Reactor cavity cooling systems (RCCSs) comprising passive safety features use the atmosphere as a coolant, which cannot be lost. However, their drawback is that they are easily affected by atmospheric disturbances. To realize the commercial application of the two types of passive RCCSs, namely RCCSs based on atmospheric radiation and atmospheric natural circulation, their safety must be evaluated, that is, they must be able to remove heat from the reactor pressure vessel (RPV) surface at all times and under any condition other than under normal operating conditions. These include both expected and unexpected natural phenomena and accidents. Moreover, they must be able to eliminate the heat leakage emitted from the RPV surface during normal operation. However, utilizing all of the heat emitted from the RPV surface increases the degree of waste heat utilization. This study aims to understand the characteristics and degree of passive safety features for heat removal by comparing RCCSs based on atmospheric radiation and atmospheric natural circulation under the same conditions. It was concluded that the proposed RCCS based on atmospheric radiation has an advantage in that the temperature of the RPV could be stably maintained against disturbances in the ambient air.

Passive Maglev Carrier Control with Consideration of Pitch Motion (피치 운동을 고려한 자기부상 수동형 이송자 제어)

  • Lee, Younghak;Kim, Chang-Hyun;Ha, Chang-Wan;Park, Doh-Young;Yang, Seok-Jo;Lim, Jaewon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.2
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    • pp.213-220
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    • 2016
  • This research aims to develop core technologies for passive carrier (no power in carrier itself) transfer system. The technologies are passive levitation, propulsion, and guidance, which can be great benefits for semiconductor and display manufacturing industries. Passive maglev carrier is necessary to precise position control for quiet and stable transfer operation. However, the structural characteristics of carrier and the installation errors of gap sensors cause the pitch motion. Hence, the controller design in consideration of pitch motion is required. This study deals with the reduction control of carrier pitch motion. PDA controller and PDA controller with pitch control are proposed to compare the pitch angle analysis. The pitch angle and the levitation precision are measured by experiment. Finally, the optimized design of pitch controller is presented and the effects are discussed.