• Title, Summary, Keyword: 양방향감쇠기

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Reducing bi-directional response of SDOF building by new type Tuned Liquid Damper (새로운 형태의 동조액체댐퍼에 의한 단자유도 건물의 양방향 응답제어)

  • Lee, Hye-Ri;Min, Kyung-Won
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.778-782
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    • 2010
  • 본 논문에서는 TLD와 TLCD를 사용한 하나의 액체 감쇠기를 이용하여 건물의 양방향 응답 제어를 연구하였다. 초고층 건물이 풍하중을 받을때는 풍방향과 풍직각방향으로 진동하여 두 개의 댐퍼를 필요로 한다. 이 논문에서 제안된 댐퍼는 건물의 양방향 응답을 하나의 감쇠기로 제어할 수 있다는 장점이 있다. 이 댐퍼의 TLCD는 건물의 주축방향으로 TLD는 주축으로 직각되는 다른 방향으로 거동을 하게 된다. 실험을 통해 양방향 감쇠기를 사용하여 건물의 양방향 응답제어를 증명하였다. 첫 번째로 양방향 감쇠기에 의한 건물의 응답제어를 알기 위한 진동대 실험을 실시하였다. 진동대 가속도를 입력으로 하고 단자유도 건물의 가속도를 출력으로 하는 전달함수를 통해 결과를 나타내었다. 실험 결과 이 연구에서 제안된 감쇠기는 단자유도 건물의 양방향 응답을 제어하였고, 비틀림 응답도 제어 하였다.

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Design Parameter of a New Type Bi-directional Damper Using a Tuned Liquid Column Damper and a Tuned Sloshing Damper (TLCD와 TSD를 이용한 새로운 형태의 양방향 감쇠기 설계변수)

  • Min, Kyung-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.8
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    • pp.850-856
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    • 2009
  • A new type bi-directional damper using a tuned liquid column damper(TLCD) and a tuned sloshing damper(TSD) is introduced in this study. Two dampers are usually needed to reduce wind-induced responses of tall buildings since they are along and across wind ones. The proposed damper has the advantage of controlling both responses with one damper. One of objectives of this study is to derive analytical dynamics to investigate coupled effects due to TLCD and TSD. Another objective is to address the effect of coupled control force due to TLCD and TSD on the dynamic characteristic of the damper based on analytical dynamics. Shaking table test is undertaken to experimentally grasp dynamic characteristics of the damper under white noise excitation. Its dynamic characteristic is expressed by the transfer function from the shaking table acceleration to the control force generated from the damper. Finally, its design parameters are identified based on the coupled dynamics, which include the mass ratio of horizontal liquid column to total liquid for a TLCD, the participation factor of the fundamental liquid sloshing for a TSD and damping ratio for both cases.

Study on Efficient Adaptive Controller for Attenuation of Engine Noises in a Car (자동차의 엔진소음 감쇠를 위한 효율적인 적응제어기에 대한 연구)

  • Kwon, Oh-Sang
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.9
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    • pp.983-989
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    • 2014
  • In this paper, a new active noise control method was proposed to decrease a weight of car, and to increase a fuel efficiency and to provide passengers' comfort and calmness, instead of a passive noise control method such as sound absorbing and insulating materials. The proposed method is an enhanced active noise controller operating by a bidirectional control algorithm. The algorithm is simple to implement and available to analyze mathematically with nearly equivalent complexity of computation. Through simulations for engine noises of a car, the proposed controller was verified that its performances of time and frequency domain were superior to those of both feedforward and feedback controllers, and it had better capability of controlling the noises when the impulsive disturbance was flow in and the response of secondary path was varied.

Performance Test of a Tuned Liquid Mass Damper installed in a Real-Scaled Structure (실물크기 구조물에 설치된 동조액체질량감쇠기의 성능실험)

  • Heo, Jae-Sung;Park, Eun-Churn;Lee, Sung-Kyung;Lee, Sang-Hyun;Kim, Hong-Jin;Jo, Ji-Seong;Cho, Bong-Ho;Joo, Seok-Jun;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.2
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    • pp.161-168
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    • 2008
  • In this paper, a tuned liquid mass damper(TLMD) was proposed and experimentally investigated on its control performance, which can control bi-axial responses of building structures by using only one device. The proposed TLMD controls the structural response in a specific one direction by using a liquid sloshing of TLCD. Also, the TLMD reduces the response of structures in the other orthogonal direction by behaving as a TMD that uses mass of the container itself and liquid within container of TLCD installed on linear motion guides. Force-vibration tests on a real-sized structure installed with the TLMD were performed to verify its independent behavior in two orthogonal directions. Test results showed that the responses of a structure were considerably reduced by using the proposed TLMD and its usefulness for structural control in two orthogonal directions.

Experiment of a Liquid Damper Controlling Bi-directional Wind Responses of a Tall Building (초고층 건물의 양방향 풍응답 제어를 위한 액체댐퍼 실험)

  • Lee, Hye-Ri;Min, Kyung-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.3
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    • pp.287-295
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    • 2010
  • This study deals with the design of a bi-directional damper using a tuned liquid damper(TLD) and a tuned liquid column damper(TLCD) for a SDOF building. Two dampers are usually needed to reduce wind-induced responses of tall buildings since they are along and across wind ones. The proposed damper has the advantage of controlling both responses with a single damper. The damper used in this study behaves as both a TLCD in a specific translational direction and a TLD in the other orthogonal direction. This paper presents experimental verification to confirm its control performance. First, shaking table test is carried out to investigate reducing responses by the damper. Control performance of the damper is expressed by the transfer function from shaking table accelerations to SDOF building ones. Testing results show that the damper reduced bi-directional responses of a SDOF building. Also, it reduced torsion responses.

Efficiency Analysis for Transmission Power Controller of VSAT (VSAT 송신전력제어기 성능 분석)

  • Hong, Sung-Taek;Shin, Gang-Wook
    • Proceedings of the KIEE Conference
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    • pp.1905-1906
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    • 2006
  • VSAT(Very Small Aperture Terminal)는 일반 가정이나 기업에서 인공위성을 이용해 양방향 통신이 가능하도록 하는 초소형 위성통신장비로 통신 인프라가 갖춰지지 못한 산간 오지지역의 정보를 실시간으로 처리해야 하는 곳을 중심으로 최근 수요가 늘고 있다. 위성 통신용으로 Ku Band 대역의 주파수를 사용하여 데이터를 전송하는 경우에는 전파가 대기권을 통과할 때 강우에 의한 감쇠를 많이 받게 되며, 회선 품질에 매우 심각한 영향을 주게 된다. 이러한 신호감쇠에 대한 보상방법으로 비콘신호의 세기를 분석하여 전력을 제어하는 방법이 제시되고 있다. 본 연구에서는 VSAT 단말지구국의 송신전력에 비례하여 출력을 제어함으로써 데이터 전송환경의 변화에 따른 전파의 세기가 감쇠되는 것을 보상하도록 VSAT의 Outlink 수신레벨을 감시하여 정해진 방법에 의해 VSAT의 Tx Attenuation을 조정하여 안정적인 위성링크 상태를 보장하도록 하는 기능과 호출 및 Event 발생시간을 저장함으로 데이터의 검보정에 활용할 수 있는 기능을 갖는 VSAT 송신전력 제어기를 개발하였으며, 단말지구국에 설치하여 운영된 데이터를 분석하고자 한다.

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Vibration Control Performance of a Two-way Tuned Liquid Mass Damper Using Real-time Hybrid Shaking Table Testing Method (실시간 하이브리드 진동대 실험법에 의한 양방향 TLMD의 진동제어 성능평가)

  • Heo, Jae-Sung;Lee, Sung-Kyung;Park, Eun-Churn;Lee, Sang-Hyun;Kim, Hong-Jin;Jo, Ji-Seong;Cho, Bong-Ho;Min, Kyung-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.5
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    • pp.485-495
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    • 2008
  • An experimental real-time hybrid method, which implements the vibration control of a building structure with only a two-way TLMD, is proposed and verified through a shaking table test. The building structure is divided into the upper experimental TLMD and the lower numerical structural part. The shaking table vibrates the TLMD with the response calculated from the numerical substructure, which is subjected to the excitations of the measured interface control force at its top story and sinusoidal waves input at its base. The results show that the conventional method can be replaced by the proposed methodology with a simple installation and accuracy for evaluating the control performance of a TLMD.

Wind Response Control Performance of a Two-way Tuned Liquid Mass Damper Using Real-Time Hybrid Shaking Table Testing Method (실시간 하이브리드 진동대 실험법에 의한 양방향 TLMD의 풍응답 제어성능평가)

  • Heo, Jae-Sung;Lee, Sung-Kyung;Lee, Sang-Hyun;Park, Eun-Churn;Kim, Hong-Jin;Jo, Bong-Ho;Jo, Ji-Seong;Kim, Dong-Young;Min, Kyung-Won
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.189-194
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    • 2007
  • An experimental real-time hybrid method, which implements the wind response control of a building structure with only a two-way TLMD, is proposed and verified through a shaking table test. The building structure is divided into the upper experimental TLMD and the lower numerical structural part. The shaking table vibrates the TLMD with the response calculated from the numerical substructure, which is subjected to the excitations of the measured interface control force at its top story and an wind-load input at its base. The results show that the conventional method can be replaced by the proposed methodology with a simple installation and accuracy for evaluating the control performance of a TLMD.

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Channel characteristics of multi-path power line using a contactless inductive coupling unit (비접촉식 유도성 결합기를 이용한 다중경로 전력선 채널 특성)

  • Kim, Hyun-Sik;Sohn, Kyung-Rak
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.9
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    • pp.799-804
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    • 2016
  • Broadband powerline communication (BPLC) uses distribution lines as a medium for achieving effective bidirectional data communication along with electric current flow. As the material characteristics of power lines are not good at the communication channel, the development of power line communication (PLC) systems for internet, voice, and data services requires measurement-based models of the transfer characteristics of the network suitable for performance analysis by simulation. In this paper, an analytic model describing a complex transfer function is presented to obtain the attenuation and path parameters for a multipath power line model. The calculated results demonstrated frequency-selective fading in multipath channels and signal attenuation with frequency, and were in good agreement with the experimental results. Inductive coupling units are used as couplers for coupling the signal to the power line to avoid physical connections to the distribution line. The inductance of the ferrite core, which depends on the frequency, determines the cut-off frequency of the inductive coupler. Coupling loss can be minimized by increasing the number of windings around the coupler. Coupling efficiency was improved by more than 6 dB with three windings compared to the results obtained with one winding.

Development of Battery-free SAW Integrated Microsensor for Real Time Simultaneous Measurement of Humidity and $CO_2$ component (습도와 $CO_2$ 농도의 실시간 동시감지를 위한 무전원 SAW 기반 집적 센서 개발)

  • Lim, Chun-Bae;Lee, Kee-Keun;Wang, Wen;Yang, Sang-Sik
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.1
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    • pp.13-19
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    • 2009
  • A 440MHz wireless and passive surface acoustic wave (SAW) based chemical sensor was developed on a $41^{\circ}YX\;LiNbO_3$ piezoelectric substrate for simultaneous measurement of $CO_2$ gas and relative humidity (RH) using a reflective delay line pattern as the sensor element. The reflective delay line is composed of an interdigital transducer (IDT) and several shorted grating reflectors. A Teflon AF 2400 and a hydrophilic $SiO_2$ layer were used as $CO_2$ and water vapor sensitive films. The coupling of mode (COM) modeling was conducted to determine optimal device parameters prior to fabrication. According to simulation results, the device was fabricated and then wirelessly measured using the network analyzer. The measured reflective coefficient $S_{11}$ in the time domain showed high signal/noise (S/N) ratio, small signal attenuation, and few spurious peaks. In the $CO_2$ and humidity testing, high sensitivity ($2^{\circ}/ppm$ for $CO_2$ detection and $7.45^{\circ}/%$RH for humidity sensing), good linearity and repeatability were observed in the $CO_2$ concentration ranges of $75{\sim}375ppm$ and humidity levels of $20{\sim}80%$RH. Temperature and humidity compensations were also investigated during the sensitivity evaluation process.

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