• Title/Summary/Keyword: spectral study

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Seismic spectral acceleration assessment of masonry in-filled reinforced concrete buildings by a coefficient-based method

  • Su, R.K.L.;Lee, C.L.;Wang, Y.P.
    • Structural Engineering and Mechanics
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    • v.41 no.4
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    • pp.479-494
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    • 2012
  • This study explores a coefficient-based seismic capacity assessment method with a special emphasis on low-rise masonry in-filled (MI) reinforced concrete (RC) buildings subjected to earthquake motion. The coefficient-based method without requiring any complicated finite element analysis is a simplified procedure to assess the maximum spectral acceleration capacity of buildings. This paper first compares the fundamental periods of MI RC structures obtained, respectively, from experimental period data and empirical period-height formulas. The coefficient-based method for low-rise masonry buildings is then calibrated by the published experimental results obtained from shaking table tests. The comparison of the experimental and estimated results indicates that the simplified coefficient-based method can provide good approximations of the maximum spectral accelerations at peak loads of the low-rise masonry reinforced concrete buildings if a proper set of drift factors and initial fundamental vibration periods of structures are used.

Surface Color Measurement Uncertainties

  • Hwang, Jisoo;Jeong, Ki-Lyong
    • Journal of the Optical Society of Korea
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    • v.19 no.6
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    • pp.649-657
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    • 2015
  • We present a surface color measurement including quantities of surface color, methods, and uncertainty evaluation. Based on a relation between spectral reflectance and surface color, we study how an uncertainty of spectral reflectance propagates to surface color. In analyzing the uncertainty propagation, we divide the uncertainty into uncorrelated components, fully correlated components, and correlated components with spectrally varying correlations. As an experimental example, we perform spectro-reflectometric measurements for ceramic color plates. With measured spectral reflectance and its uncertainty evaluation, we determine surface color and analyze uncertainties of the ceramic color plates.

LEAST-SQUARES SPECTRAL COLLOCATION PARALLEL METHODS FOR PARABOLIC PROBLEMS

  • SEO, JEONG-KWEON;SHIN, BYEONG-CHUN
    • Honam Mathematical Journal
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    • v.37 no.3
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    • pp.299-315
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    • 2015
  • In this paper, we study the first-order system least-squares (FOSLS) spectral method for parabolic partial differential equations. There were lots of least-squares approaches to solve elliptic partial differential equations using finite element approximation. Also, some approaches using spectral methods have been studied in recent. In order to solve the parabolic partial differential equations in parallel, we consider a parallel numerical method based on a hybrid method of the frequency-domain method and first-order system least-squares method. First, we transform the parabolic problem in the space-time domain to the elliptic problems in the space-frequency domain. Second, we solve each elliptic problem in parallel for some frequencies using the first-order system least-squares method. And then we take the discrete inverse Fourier transforms in order to obtain the approximate solution in the space-time domain. We will introduce such a hybrid method and then present a numerical experiment.

A Study on the Sonar Data Processing by Using a Discrete Wavelet Transform (이산 웨이브릿 변환을 이용한 소나 자료처리에 관한 연구)

  • Kim, Jin-Hoo;Kim, Hyun-Do
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.324-329
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    • 2003
  • Spectral analysis is an important signal processing tool for time series data. The transformation of a time series into the frequency domain is the basis for a significant number of processing algorithms and interpretive methods. Recently developed transforms based on the new mathematical field of wavelet analysis bypass the resolution limitation and offer superior spectral decomposition. The discrete wavelet transform of Sonar data provides spectral localization of noises, hence noises can be filtered out successfully.

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A Study on a Improvement of the Speech Quality with Variable Window in CELP Vocoder (가변 윈도우를 이용한 CELP 부호화기의 음질 향상에 관한 연구)

  • Ju, Sang-Gyu
    • Proceedings of the KAIS Fall Conference
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    • 2010.05a
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    • pp.265-268
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    • 2010
  • There have been proposed two types of low bit rate vocoder upto now : One is MBE type using the spectrum modeling and another is CELP type using the hybrid coding method. CELP type vocoder has mainly studied between them. Specially, much of intensity is concentrated in CELP vocoder due to the emergence of Internet Phone and PCS in a domestic. In order to improve the speech quality in CELP vocoder, in this paper, we proposed a new spectrum analysis algorithm with variable window. In CELP vocoder, the spectrum of the synthesised speech signal is distorted because the fixed size windows is used for spectrum analysis. So we have measured the spectral leakage and in order to minimize the spectral leakage have adjusted the window size. Applying this method G.723.1 ACELP, we can get SD(Spectral Distortion) reduction 0.084(dB), residual energy reduction 6.3% and MOS(Mean Opinion Score) improvement 0.1.

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Microblog Sentiment Analysis Method Based on Spectral Clustering

  • Dong, Shi;Zhang, Xingang;Li, Ya
    • Journal of Information Processing Systems
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    • v.14 no.3
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    • pp.727-739
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    • 2018
  • This study evaluates the viewpoints of user focus incidents using microblog sentiment analysis, which has been actively researched in academia. Most existing works have adopted traditional supervised machine learning methods to analyze emotions in microblogs; however, these approaches may not be suitable in Chinese due to linguistic differences. This paper proposes a new microblog sentiment analysis method that mines associated microblog emotions based on a popular microblog through user-building combined with spectral clustering to analyze microblog content. Experimental results for a public microblog benchmark corpus show that the proposed method can improve identification accuracy and save manually labeled time compared to existing methods.

Coherent Analysis of HVAC Using the Multi-Dimensional Spectral Analysis (다차원 스펙트럼 해석법을 이용한 자동차 공조시스템의 기여도분석)

  • Hwang, Dong-Kun;Oh, Jae-Eung;Lee, Jung-Youn;Kim, Sung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.999-1004
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    • 2004
  • In this study, we identify contribution of structure-borne-noise of vehicle HVAC system using Multi-Dimensional spectral analysis (MDSA) method. Firstly, to identify the applicability of MDSA method, the case of HVAC system was modeled with four input / single output system. The four inputs which is given vibration data is composed of blower, evaporator, heater and duct. The single output is noise data from driver's seat. When the blower motor is operating, we analyze the contributions of four input / single output. As a result of experiment, we identify efficiency of systems modeled with four input / single output through ordinary coherence function (OCF) and multiple coherence function (MCF).

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Transfer Path Analysis of Output Noise Using Multi-dimensional Spectral Analysis Method for Vacuum Cleaner (다차원 스펙트럼 해석법을 이용한 진공청소기 출력소음의 전달경로 해석)

  • Jeong, Jae-Eun;Lee, Jung-Hwan;Chung, Chang-Ook;Hwang, Geun-Bae;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.10
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    • pp.940-945
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    • 2010
  • Noise reduction of vacuum cleaner is important, according as get into standard that estimate quality of product. To reduce noise of vacuum cleaner, we need analysis of correct noise source and contribution grasping about Identified noise sources' output noise. Because noise sources' correlation exists in vacuum cleaner that is small and complicated system, analysis is not easy. In this case, we need to apply Multi-dimensional spectral analysis(MDSA) method that can remove correlation between noise sources and grasp pure contribution degree of noise sources. In this study, we take transfer path analysis between output noise and noise that measured in inside/outside of vacuum cleaner.

The Synthesis of Red-Sensitizing Dye for Color Photography (천연색 사진용 적감색소의 합성)

  • Kim, Yeoung-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.18 no.2
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    • pp.136-141
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    • 2001
  • Naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. In this study, red-sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-naphthothiazolium(inner salt) with triethyl orthoacetate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, Mass spectrometer, $^{1}H-NMR$ spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 573nm. Therefore, it was concluded that naphthothiazolo carbocyanine dye can be used as red0sensitizing dye for the spectral sensitization of photographic emulsion.

Synthesis of 9-Phenyl-5,5'-Diphenyl-3,3'-Bis(3-Sulfopropyl)-Benzoxazolo Carbocyanine Triethyl Ammonium Salt (9-Phenyl-5,5'-Diphenyl-3,3'-Bis(3-Sulfopropyl)-Benzoxazolo Carbocyanine Triethyl Ammonium Salt의 합성)

  • Kim, Yeoung-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.2
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    • pp.226-231
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    • 2008
  • In this study, benzoxazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization. Sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-benzoxazolium (inner salt) with triethyl orthobenzoate in the presence of triethylamine. The product was identified by using various analytical tools such as elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, $^1H$-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 507 nm. Therefore, it was concluded that benzoxazolo carbocyanine dye can be used as sensitizing dye for the spectral sensitization of photographic emulsion and color cosmetics.