• 제목/요약/키워드: Coherent-Analysis

검색결과 323건 처리시간 0.023초

자동차용 모듈화 도어의 동특성 평가 시험법 개발 (The Development of Evaluation Process for Dynamic Characteristics of Door Module)

  • 배철용;김찬중;권성진;이봉현;장운성;이준우
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.291-296
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    • 2007
  • This study presents the evaluation process for door module. Its objective evades the resonance generated at module plate due to the operation of window regulator motor. For this study, the design improvement process is composed of experimental methods having three steps. First step is modal analysis at door assembly status for acquisition of dynamic characteristics which are modal frequency and damping. Second step is a vibration experiment to get the test mode considered an efficiency of window regulator motor. Last step is a vibration measurement by the form of $6{\times}6$ array on module plate. A vibration measurement of 6x6 array form can be got to three analysis results which are a transfer path of vibration using cross correlation function, a vibration map using OA level and a contribution by frequency band using coherent output power spectrum on module plate. These results are applied to SDM(structural dynamic modification) for design improvement to get around the resonance on module plate by the excitation of window regulator motor.

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다차원 스펙트럼 해석법을 이용한 PDP TV의 저소음화 (Noise Reduction of PDP TV Using Multi-dimensional Spectral Analysis Method)

  • 양인형;정재은;곽형택;오재응
    • 한국소음진동공학회논문집
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    • 제21권1호
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    • pp.81-88
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    • 2011
  • The method is introduced for estimating the noise source contribution on the noise of PDP TV in a multiple-input system where the input sources may be coherent with each other. By the coherence function method, it is found that the biggest part of the noise source in the PDP TV noise is generated by the PCB boards which consume high power and produce high heat. This analysis is modeled as three-input/single-output system because the noise is generated by three main boards, X-board, Y-board, SMPS that are located close to each other. The coherence function method is proved to be useful tool for identifying of noise source. In this study, Transfer Path Analysis using MDSA is implemented to determine the quantitative noise contribution of each board for PDP TV with the rear case closed and with the rear case open. And the possibility of noise reduction is confirmed through the experimental method that isolates the most contributing board by adding sound-absorbing materials to it.

From proteomics toward systems biology: integration of different types of proteomics data into network models

  • Rho, Sang-Chul;You, Sung-Yong;Kim, Yong-Soo;Hwang, Dae-Hee
    • BMB Reports
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    • 제41권3호
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    • pp.184-193
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    • 2008
  • Living organisms are comprised of various systems at different levels, i.e., organs, tissues, and cells. Each system carries out its diverse functions in response to environmental and genetic perturbations, by utilizing biological networks, in which nodal components, such as, DNA, mRNAs, proteins, and metabolites, closely interact with each other. Systems biology investigates such systems by producing comprehensive global data that represent different levels of biological information, i.e., at the DNA, mRNA, protein, or metabolite levels, and by integrating this data into network models that generate coherent hypotheses for given biological situations. This review presents a systems biology framework, called the 'Integrative Proteomics Data Analysis Pipeline' (IPDAP), which generates mechanistic hypotheses from network models reconstructed by integrating diverse types of proteomic data generated by mass spectrometry-based proteomic analyses. The devised framework includes a serial set of computational and network analysis tools. Here, we demonstrate its functionalities by applying these tools to several conceptual examples.

자동차용 모듈화 도어의 동특성 분석에 관한 연구 (A Study on the Dynamic Characteristics of Door Module for Vehicle)

  • 배철용;김찬중;권성진;이봉현;장운성;이준우
    • 한국소음진동공학회논문집
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    • 제17권11호
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    • pp.1093-1101
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    • 2007
  • This study presents the design improvement process for door module. Its objective evades the resonance generated at module plate due to the operation of window regulator motor. For this study, the design improvement process is composed of experimental methods having three steps. First step is modal analysis at door assembly status for acquisition of dynamic characteristics which are modal frequency and damping. Second step is a vibration experiment to get the test mode considered an efficiency of window regulator motor. Last step is a vibration measurement by the form of $6{\times}6$ array on module plate. A vibration measurement of $6{\times}6$ array form can be got to three analysis results which are a transfer path of vibration using cross correlation function, a vibration map using OA level and a contribution by frequency band using coherent output power spectrum on module plate. These results are applied to SDM(structural dynamic modification) for design improvement to get around the resonance on module plate by the excitation of window regulator motor.

원형 실린더를 지나는 난류 유동장의 직접수치해석과 큰 에디모사를 위한 스케일 간 상호작용 연구 (DNS and Analysis on the Interscale Interactions of the Turbulent Flow past a Circular Cylinder for Large Eddy Simulation)

  • 김택근;박노마;유정열
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1801-1806
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    • 2004
  • Stochastic nature of subgrid-scale stress causes the predictability problem in large eddy simulation (LES) by which the LES solution field decorrelates with field from filtered directnumerical simulation (DNS). In order to evaluate the predictability limit in a priori sense, the information on the interplay between resolved scale and subgrid-scale (SGS) is required. In this study, the analysis on the inter-scale interaction is performed by applying tophat and cutoff filters to DNS database of flow over a circular cylinder at Reynolds number of 3900. The effect of filter shape is investigated on the interpretation of correlation between scales. A critique is given on the use of tophat filter for SGS analysis using DNS database. It is shown that correlations between Karman vortex and SGS kinetic energy drastically decrease when the cutoff filter is used, which implies that the small scale universality holds even in the presence of the large scale coherent structure.

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Rayleigh-Quotient and Iterative-Threshold-Test-Based Blind TOA Estimation for IR-UWB Systems

  • Shen, Bin;Zhao, Chengshi;Cui, Taiping;Kwak, Kyung-Sup
    • ETRI Journal
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    • 제32권2호
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    • pp.333-335
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    • 2010
  • This letter proposes a non-coherent blind time-of-arrival (TOA) estimation scheme for impulse radio ultra-wideband systems. The TOA estimation is performed in two consecutive phases: the Rayleigh-quotient theorem-based coarse-signal acquisition (CSA) and the iterative-threshold-test-based fine time estimation (FTE). The proposed scheme serves in a blind manner without demanding any a priori knowledge of the channel and the noise. Analysis and simulations demonstrate that the proposed scheme significantly increases the signal detection probability in CSA and ameliorates the TOA estimation accuracy in FTE.

다매체 직접수열 대역확산 다중접속 시스템의 성능분석 (performance Evaluation of a Multi-Media DS/SSMA System)

  • 김홍직;송익호;김상우;한진희
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 1996년도 학술대회
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    • pp.33-38
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    • 1996
  • A multi-media binary DS/CDMA system with variable processing gain and coherent correlation receivers are considered under additive white Gaussian noise channels. Two types of information sources with different rates and transmitting powers are assumed to be transmitted simultaneously in the same channel. Average signal-to-noise ratios at the correlation receiver outputs for each type of information sources are analytically derived as functions of discrete partial cross-correlations between spreading code sequences. The analysis is expected to provide analytical tools for use in preliminary system design and spreading code selection.

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GSM환경에서의 기지국 안테나 어레이 성능 분석에 관한 연구 (Research for Performance Analysis of Antenna Arrays in Basestation for GSM System)

  • 장병건;전창대
    • 한국전자파학회논문지
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    • 제16권7호
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    • pp.740-745
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    • 2005
  • 본 논문은 GSM 시스템의 다경로 환경에서 선형 제약형 어레이 처리기를 이용하여 주종형 어레이 처리와 공간 유화 방법으로 원하는 신호를 추정하는 성능에 대하여 논한다. SINR과 BER 성능에서 주종형 어레이 처리방법과 공간유화 방법이 선형 제약형 어레이 처리방법보다 우수한 반면, 공간 유화 방법의 성능이 주종형 어레이 처리기 보다 더 나은 것으로 나타났다.

New Analysis on Reception of M-ary FSK Signals over Rician Fading Channels

  • Kim, Chang-Hwan;Han, Young-Yearl
    • 한국전자파학회논문지
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    • 제11권7호
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    • pp.1176-1185
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    • 2000
  • In this paper, we analyze the distribution of the envelope of the received signal over frequency-nonselective slow Rician fading channels with aadditive white Gaussian noise(AWGN). Especially, we can obtain the error rate performance of noncoherent M-ary FSK(MFSK) over slow and flat Rician fading channels and AWGN from the new probability density function(PDF) of the envelope, not PDF of the instantaneous signal-to-noise ratio(SNR) published before, of the received signal. When coherent MFSK signals experience the Rician fading channel, the performances are derived, using the union bound.

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가진된 덤프 연소기 내에서의 비예혼합 화염 거동 (Behavior of Non-premixed Flame Front in an Acoustically-Driven Dump Combustor)

  • 박정규;신현동
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2000년도 제20회 KOSCO SYMPOSIUM 논문집
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    • pp.142-151
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    • 2000
  • Dump combustor is a combustor having a dump plane to make coherent structures. A non-premixed flame dump combustor of simple geometry was constructed. We conducted basic experiments such as frequency response on the combustor to confirm the characteristics of the phenomena as a typical dump combustion and unsteady combustion. Furthermore we visualized the flame front behavior by CH chemiluminescence and high speed motion analysis. In spite of the lack of another data such as velocity, species concentration and temperature, the results showed not only the periodic motion of flame front but the ignition process of vortex ring flame. Also we could check out Rayleigh criterion by combining the visualization data with the pressure data.

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