• Title/Summary/Keyword: Quantitative parameters

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Quantitative Morphology of High Redshift Galaxies Using GALEX Ultraviolet Images of Nearby Galaxies

  • Yeom, Bum-Suk;Rey, Soo-Chang;Kim, Young-Kwang;Kim, Suk;Lee, Young-Dae
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.73.1-73.1
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    • 2011
  • An understanding of the ultraviolet (UV) properties of nearby galaxies is essential for interpreting images of high redshift systems. In this respect, the prediction of optical-band morphologies at high redshifts requires UV images of local galaxies with various morphologies. We present the simulated optical images of galaxies at high redshifts using diverse and high-quality UV images of nearby galaxies obtained through the Galaxy Evolution Explorer (GALEX). We measured CAS (concentration, asymmetry, clumpiness) as well as Gini/M20 parameters of galaxies at near-ultraviolet (NUV) and simulated optical images to quantify effects of redshift on the appearance of distant stellar systems. We also discuss the change of morphological parameters with redshift.

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Construction of a Gait Analysis System for Evaluating Gait Abnormalities (보행 비정상성의 평가를 위한 보행분석 시스템의 구현)

  • Chung, Min-Keun;Kim, Sang-Ho;Kim, Tae-Bok
    • Journal of Korean Institute of Industrial Engineers
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    • v.17 no.2
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    • pp.39-50
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    • 1991
  • The movement of human beings - walking, running, jumping and climbing, etc. - have long been of scientific interest. In particular, the science of human walking is called gait analysis. Various instruments have been developed to assist in the study of human gait. Recently gait analysis techniques are used in medical research to investigate the abnormalities of pathological gait. In this study, we constructed a comprehensive gait analysis system consisting of a walkway, a force platform, foot-switches and an ExpertVision motion analysis system. Time-distance gait parameters and vector diagrams can be analyzed by a special application program called Force Analysis System(FOANAS). Using quantitative discrimination of this system, the gait characteristic parameters of normal and pathological gait is facilitated.

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Ultrasonic Diagnosis of Osteoporosis (초음파를 이용한 골다공증 진단)

  • Lee, Kang-Il;Yoon, Suk-Wang
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.2E
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    • pp.64-72
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    • 2010
  • Osteoporosis is a skeletal disease characterized by two factors: reduced bone mass and microstructure disruption of bone tissue. These symptoms increase bone fragility and can contribute to eventual fracture. In recent years, quantitative ultrasound (QUS) technologies have played a growing role in the diagnosis of osteoporosis. Most of the commercial bone sonometers measure speed of sound and/or broadband ultrasound attenuation at peripheral skeletal sites. However, QUS parameters are purely empirical measures that have not yet been firmly linked to physical parameters, such as bone strength or porosity, and the underlying physics for their variations in cancellous bone is not well understood yet. This paper reviews the QUS technologies for the diagnosis of osteoporosis and also addresses several theoretical models, such as the Biot model, the scattering model, the stratified model, and the modified Biot-Attenborough model, for ultrasonic wave propagation in bone.

Determination of Halogen Elements in Volatile Organohalogen Compounds by the Wickbold Combustion Pretreatment Method and Ion Chromatography

  • Lee, Dong-Ho;Kwon, Soo-Han;Kim, Soo-Hwan;Lee, Sang-Hun;Min, Bum-Chan
    • Bulletin of the Korean Chemical Society
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    • v.28 no.1
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    • pp.59-62
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    • 2007
  • A quantitative analysis method of halogen elements in volatile organohalogen compounds was established by the Wickbold combustion pretreatment in an enclosed system and ion chromatography. The sample pretreatment parameters of Wickbold combustion were experimentally optimized, and using the determined optimal pretreatment parameters, the reproducibility was estimated by ion chromatography. As a comparison for real samples, NIST certified reference materials (CRMs) were analyzed for the recovery efficiency and reproducibility.

Parametric Study of Multi-Element Airfoils' Aerodynamic Characteristics (다중-익형의 공력 특성에 대한 파라미터 연구)

  • Park Min-Jeoung;Kim Byoungsoo
    • 한국전산유체공학회:학술대회논문집
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    • 2002.05a
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    • pp.88-93
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    • 2002
  • In the present research, a parametric study of aerodynamic characteristics for multi-element airfoils is performed. The major geometric parameters of interest are the gap distance between airfoils and relative deflection angle of slat/flap. The present results are mainly obtained by using inviscid flow calculation, and the aerodynamic characteristics are focused on the surface pressure distribution and the lifts. The results of the present research may be used as not only qualitative data but also quantitative data for small angle of attack flows, where the viscous effect does not play major role in terms of surface pressure distribution and lifts. A further research in this subject including viscous calculation and more geometric parameters is to be performed in the future.

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A Study on Temperature Distribution and Bead Geometry in GMA Welding (GMA 용접에 온도분포와 비드형상에 관한 연구)

  • 김일수;박창언;송창재;정영재;김동규
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.05a
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    • pp.111-116
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    • 1999
  • Over the last few years, there has been a growing interest in quantitative representation of heat transfer and fluid flow phenomena in weld pools in order to relate the processing conditions to the quality of the weldment produced and to use this information for the optimization and robotization of the welding process. Normally, a theoretical model offers a powerful alternative to estimate the important input parameters and to calculate the effects of varying any of parameters. To solve this problem, a transient 2D(two-dimensional) heat conduction and a transient 2D axisymmetric heat and fluid model were developed for determining weld bead geometry and temperature distribution for the GMA(Gas Metal Arc) welding process. The equation was solved using a general thermofluid-mechanics computer program, PHOENICS code, which is based on the SIMPLE algorithm. The simulation results showed that the calculated bead geometry from two developed models reasonably agree with the experiment result.

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Resolution Analysis of Axially Distributed Image Sensing Systems under Equally Constrained Resources

  • Cho, Myungjin;Shin, Donghak
    • Journal of the Optical Society of Korea
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    • v.17 no.5
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    • pp.405-409
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    • 2013
  • In this paper, a unifying framework to evaluate the depth resolution of axially distributed image sensing (ADS) systems under fixed resource constraints is proposed. The proposed framework enables one to evaluate the system performance as a function of system parameters such as the number of cameras, the number of pixels, pixel size, and so on. The Monte Carlo simulations are carried out to evaluate ADS system performance as a function of system parameters. To the best of our knowledge, this is the first report on quantitative analysis of ADS systems under fixed resource constraints.

홍수시 저수지운영을 위한 시우량 모형 - Hyetograph model for Reservoir operation during Flash flood

  • Lee, Jae-Hyeong;;Jeong, Dong-Guk
    • Water for future
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    • v.23 no.3
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    • pp.341-350
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    • 1990
  • Precise run-off forecasting depends on the ability to predict quantitative rainfall intensity. This study suggests a stochastic model for 1 hour order rainfall prediction. The model simultaneously predicts rainfall intensity at all telemetered rain-gauge locations. All model parameters, velocity and direction of storm movement, radial spectrum, dimensionless time distribution of rainfall, are estimated from telemetered and historical data for the basin being predicted. Also the estimated parameters are based on the previous study. The results are the influence of dimensionless time distributions on the prediction and the model on run-off.

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Prediction of Sorption/Desorption Parameters of Halogenated Aliphatic Compounds Using QSAR (QSAR을 이용한 지방족 할로겐화합물 흡착 및 탈착 계수의 예측)

  • 김종오;박증석;최연돈
    • Journal of Environmental Science International
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    • v.11 no.7
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    • pp.737-742
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    • 2002
  • Sorption and desorption is an important phenomenon to determine the fate of halogenated aliphatic hydrocarbons in the aqueous phase. This study was conducted to develope a predictive equation capable of estimating the sorption and desorption potentials of halogenated aliphatic hydrocarbons onto the sludge from activated process, sediment, and clay. It has shown that the sorption and desorption parameters can be accurately estimated using Quantitative Structural Activity Relationship(QSAR) models based on molecular connectivity indexes of test compounds. The QSAR model could be applied to predict the sorption and desorption capacity of the other halogenated aliphatic hydrocarbons. The QSAR modeling would provide a useful tool to predict the sorption and desorption capacity without time-consuming experiments.

Experimental Study on Manoeuvring Hydrodynamic Derivatives and Interaction Coefficients of Full Form Ship (비대선형의 조종 유체력 미계수 및 간섭 계수에 관한 실험적 연구)

  • 최명식;윤점동;이경우
    • Journal of the Korean Institute of Navigation
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    • v.18 no.4
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    • pp.49-57
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    • 1994
  • In marine transportation of bulk cargoes such as crude oil. ore, coal etc., a lot of full form ship which have poor manoeuvrability were presented in many countries. Since ship manoeuvrability depends upon many parameters namely hydrodynamic derivatives, interference factors etc., as external forces, it is of great importance that we investigate these values of parameters on analysis of manoeuvrability. In this paper, we investigated and analyzed interaction coefficients among hull-propeller-rudder for a full form ship by captive model test in circulating water channel, and then compared with experimental results by PMM test. A tanker model ship which has 0.83 as block coefficient and MMG mathematical models were used in this experiment. Almost same tendencies were found in qualitative analysis, even though more serial experiments were demanded in quantitative analysis.

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