• Title, Summary, Keyword: spectra

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A Study on Stethoscope Signal Analysis for Normal and Heart-diseased Children (정상 및 심질환 소아의 청진음 분석에 관한 연구)

  • Kim, Dong-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.4
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    • pp.715-720
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    • 2017
  • This study tries to analyze morphology and formant frequencies of linear prediction spectra of stethoscope sounds for heart diseased children. For this object, heart diseased stethoscope sounds were collected in the pediatrics of an university hospital. The collected signals were preprocessed and analyzed by the Burg algorithm, a kind of linear prediction analysis. The linear prediction spectra and the formant frequencies of the spectra for the stethoscope sounds for the normal and the diseased children are estimated and compared. The spectra showed outstanding differences in morphology and formant frequencies between the normal and the diseased children. Normal children showed relatively low frequency of F1(the first formant) and small negative slope from F1. VSD children revealed stiff slope change around F1 to F3. Spectra of ASD children is similar with the normal case, but have negative values of F3. F1-F2 difference of the functional murmur children were relatively large.

Two-Dimensional Correlation Analysis of Sum-Frequency Vibrational Spectra of Langmuir Monolayers

  • Lee, Jonggwan;Sung, Woongmo;Kim, Doseok
    • Journal of the Optical Society of Korea
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    • v.18 no.5
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    • pp.558-563
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    • 2014
  • Sum-frequency generation spectra of a Langmuir monolayer on water surface at varying surface areas were studied with two-dimensional correlation analysis. Upon enlarging the area/molecule of the Langmuir monolayer, the sum-frequency spectra changed reflecting the conformation change of the alkyl chains of the molecules in the monolayer. These changes stood out more clearly by employing two-dimensional correlation analysis of the above sum-frequency spectra. Features not very pronounced in the original spectra such as closely-spaced spectral bands can also be easily distinguished in the two-dimensional correlation spectra.

HIGH-RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASARS

  • Le, Huynh Anh Nguyen;Pak, Soojong;Im, Myungshin;Ho, LuisC.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.91-91
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    • 2012
  • We present high-resolution near-infrared host galaxy spectra of low-z quasars, PG0844+349 (z=0.064), PG1226+023 (z=0.158), and PG1426+015 (z=0.086). The observation was done by using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The full width at half maximum of the point spread function was about 0.3 arcsec by using an Adaptive Optics system, which can effectively resolve the quasar spectra from the host galaxy spectra. The signal-to-noise ratios are increased by the total exposure time up to several hours per targets and the development of data reduction method. We compare our results to the stellar spectra library and sample spectra from Dasyra et al. (2007) and Watson et al. (2008). The identified spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bulge of the host galaxy.

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SPECTRA OF REFLECTED SUNLIGHT FROM PLANETS

  • LEE, DONG-EUN;SONG, IN-OK
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.767-768
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    • 2015
  • Spectra of reflected sunlight from Mars and Jupiter are presented. They were obtained from an educational 1-D array spectrograph covering almost a full range of visible wavelengths, 200~900 nm with 1 nm spectral resolution. The question was whether a spectral difference could be obtained between that of terrestrial planets and gas planets with an educational spectrograph. It was installed in a 12-inch reflecting telescope at the Korea Science Academy of KAIST in Busan. Both spectra show clear absorption lines of reflected sunlight. They shows differences oin line presence, but are not very significant. This work means that the spectrograph successfully observed the reflected spectra of planets and can detect differences in spectra in terms of the absence and presence of absorption lines of planets.

Load spectra growth modelling and extrapolation with REBMIX

  • Volk, Matej;Fajdiga, Matija;Nagode, Marko
    • Structural Engineering and Mechanics
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    • v.33 no.5
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    • pp.589-604
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    • 2009
  • In the field of predicting structural safety and reliability the operating conditions play an essential role. Since the time and cost limitations are a significant factors in engineering it is important to predict the future operating conditions as close to the actual state as possible from small amount of available data. Because of the randomness of the environment the shape of measured load spectra can vary considerably and therefore simple distribution functions are frequently not sufficient for their modelling. Thus mixed distribution functions have to be used. In general their major weakness is the complicated calculation of unknown parameters. The scope of the paper is to investigate the load spectra growth for actual operating conditions and to investigate the modelling and extrapolation of load spectra with algorithm for mixed distribution estimation, REBMIX. The data obtained from the measurements of wheel forces and the braking moment on proving ground is used to generate load spectra.

A Study on the Surface Treatment of Spectra Fibers Using an ion Assisted Reaction Method (이온도움 반응법을 이용한 스펙트라 섬유의 표면처리에 대한 연구)

  • 이경엽;신동혁;지창헌
    • Journal of the Korean institute of surface engineering
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    • v.35 no.5
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    • pp.319-324
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    • 2002
  • It is known that ion-assisted reaction method is effective for the surface modification of polymers. The surface treatment of Spectra fibers using the ion-assisted reaction method was investigated in the present study The Spectra fibers were treated by $Ar^{+}$ / ion irradiation under oxygen environment. The treatment was carried out at different $Ar^{+}$ ion doses. The$ Ar^{+ }$ /ion doses used were $6$\times$10^{15}$ , $1$\times$10^{16}$ , $5$\times$10^{16}$ , $1$\times$10^{17}$ / ions/$\m^2$. Optimal $Ar^{+}$ ion dose in the treatment of Spectra fibers was determined by measuring the tensile strength and modulus of Spectra/vinylester composites as a function of ion dose. It was found that the optimal ion dose was $1$\times$10^{16}$ions/$\m^2$. It was also found from the scanning electron microscope examination that the surface-treatment improved adhesion between fibers and vinylester resin.

Synthesis, Crystal Structure, Spectra Characterization and DFT Studies on a Di-Cycle Pyrazoline Derivative

  • Song, Jie;Zhao, Pu Su;Zhang, Wei Guang
    • Bulletin of the Korean Chemical Society
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    • v.31 no.7
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    • pp.1875-1880
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    • 2010
  • A dicycle pyrazoline derivative, 1-phenyl-5-(p-fluorophenyl)-3,4-($\alpha$-p-fluoro-tolylenecyclohexano) pyrazoline, was synthesized and characterized by elemental analysis, IR, UV-vis, fluorescence spectra and X-ray single crystal diffraction. Density function theory (DFT) calculations were performed by using B3LYP method with 6-$311G^{**}$ basis set. The optimized geometry can well simulate the molecular structure. Vibrational frequencies were predicted, assigned and compared with the experimental values, which suggest that B3LYP/6-$311G^{**}$ method can well predict the IR spectra. Both the experimental electronic absorption spectra and the predicted ones by B3LYP/6-$311G^{**}$ method reveal three electron-transition bands, with the theoretical ones having some red shifts compared with the experimental data. Natural bond orbital analyses indicate that the absorption bands are mainly derived from the contribution of n $\rightarrow\pi^*$ and $\pi\rightarrow\pi^*$ transitions. Fluorescence spectra determination shows that the title compound can emit blue-light at about 478 nm. On the basis of vibrational analysis, the thermodynamic properties of title compound at different temperature have been calculated, revealing the correlations between $C^0_{p,m}$, $S^0_m$, $H^0_m$ and temperature.

Estimating floor spectra in multiple degree of freedom systems

  • Calvi, Paolo M.;Sullivan, Timothy J.
    • Earthquakes and Structures
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    • v.7 no.1
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    • pp.17-38
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    • 2014
  • As the desire for high performance buildings increases, it is increasingly evident that engineers require reliable methods for the estimation of seismic demands on both structural and non-structural components. To this extent, improved tools for the prediction of floor spectra would assist in the assessment of acceleration sensitive non-structural and secondary components. Recently, a new procedure was successfully developed and tested for the simplified construction of floor spectra, at various levels of elastic damping, atop single-degree-of-freedom structures. This paper extends the methodology to multi-degree-of-freedom (MDOF) supporting systems responding in the elastic range, proposing a simplified modal combination approach for floor spectra over upper storeys and accounting for the limited filtering of the ground motion input that occurs over lower storeys. The procedure is tested numerically by comparing predictions with floor spectra obtained from time-history analyses of RC wall structures of 2- to 20-storeys in height. Results demonstrate that the method performs well for MDOF systems responding in the elastic range. Future research should further develop the approach to permit the prediction of floor spectra in MDOF systems that respond in the inelastic range.

Capacity spectrum method based on inelastic spectra for high viscous damped buildings

  • Bantilas, Kosmas E.;Kavvadias, Ioannis E.;Vasiliadis, Lazaros K.
    • Earthquakes and Structures
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    • v.13 no.4
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    • pp.337-351
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    • 2017
  • In the present study a capacity spectrum method based on constant ductility inelastic spectra to estimate the seismic performance of structures equipped with elastic viscous dampers is presented. As the definition of the structures' effective damping, due to the damping system, is necessary, an alternative method to specify the effective damping ratio ${\xi}eff$ is presented. Moreover, damping reduction factors (B) are introduced to generate high damping elastic demand spectra. Given the elastic spectra for damping ratio ${\xi}eff$, the performance point of the structure can be obtained by relationships that relate the strength demand reduction factor (R) with the ductility demand factor (${\mu}$). As such expressions that link the above quantities, known as R - ${\mu}$ - Τ relationships, for different damping levels are presented. Moreover, corrective factors (Bv) for the pseudo-velocity spectra calculation are reported for different levels of damping and ductility in order to calculate with accuracy the values of the viscous dampers velocities. Finally, to evaluate the results of the proposed method, the whole process is applied to a four-storey reinforced concrete frame structure and to a six-storey steel structure, both equipped with elastic viscous dampers.