• Title/Summary/Keyword: Dispersion analysis

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Approaches to measurement system analysis in quality management (품질경영에서 측정시스템분석 방안)

  • Baik, Jaiwook
    • Industry Promotion Research
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    • v.6 no.3
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    • pp.19-24
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    • 2021
  • There should be no problem in the measurement system for scientific quality management. In this paper, we want to correctly identify the factors that can affect the measurement results during the measurement process and identify what causes them when the measurement results cause problems in terms of location and variation. Variations in the measurement system are largely described in terms of location and dispersion. Location-related attributes are accuracy, stability, and linearity while dispersion-related attributes are reproducibility and repeatability. Analyzing the factors associated with dispersion is an R&R analysis, in which the size of repeatability and reproducibility is represented by a range of differences between multiple measurements and a range of differences between measurements, and 99% of dispersion is determined. Experimental design can also be used for measurement system analysis. Proper analysis is performed only when the factors causing the fluctuation, the worker and the product, are correctly identified as random or fixed factors.

Informative Role of Marketing Activity in Financial Market: Evidence from Analysts' Forecast Dispersion

  • Oh, Yun Kyung
    • Asia Marketing Journal
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    • v.15 no.3
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    • pp.53-77
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    • 2013
  • As advertising and promotions are categorized as operating expenses, managers tend to reduce marketing budget to improve their short term profitability. Gauging the value and accountability of marketing spending is therefore considered as a major research priority in marketing. To respond this call, recent studies have documented that financial market reacts positively to a firm's marketing activity or marketing related outcomes such as brand equity and customer satisfaction. However, prior studies focus on the relation of marketing variable and financial market variables. This study suggests a channel about how marketing activity increases firm valuation. Specifically, we propose that a firm's marketing activity increases the level of the firm's product market information and thereby the dispersion in financial analysts' earnings forecasts decreases. With less uncertainty about the firm's future prospect, the firm's managers and shareholders have less information asymmetry, which reduces the firm's cost of capital and thereby increases the valuation of the firm. To our knowledge, this is the first paper to examine how informational benefits can mediate the effect of marketing activity on firm value. To test whether marketing activity contributes to increase in firm value by mitigating information asymmetry, this study employs a longitudinal data which contains 12,824 firm-year observations with 2,337 distinct firms from 1981 to 2006. Firm value is measured by Tobin's Q and one-year-ahead buy-and-hold abnormal return (BHAR). Following prior literature, dispersion in analysts' earnings forecasts is used as a proxy for the information gap between management and shareholders. For model specification, to identify mediating effect, the three-step regression approach is adopted. All models are estimated using Markov chain Monte Carlo (MCMC) methods to test the statistical significance of the mediating effect. The analysis shows that marketing intensity has a significant negative relationship with dispersion in analysts' earnings forecasts. After including the mediator variable about analyst dispersion, the effect of marketing intensity on firm value drops from 1.199 (p < .01) to 1.130 (p < .01) in Tobin's Q model and the same effect drops from .192 (p < .01) to .188 (p < .01) in BHAR model. The results suggest that analysts' forecast dispersion partially accounts for the positive effect of marketing on firm valuation. Additionally, the same analysis was conducted with an alternative dependent variable (forecast accuracy) and a marketing metric (advertising intensity). The analysis supports the robustness of the main results. In sum, the results provide empirical evidence that marketing activity can increase shareholder value by mitigating problem of information asymmetry in the capital market. The findings have important implications for managers. First, managers should be cognizant of the role of marketing activity in providing information to the financial market as well as to the consumer market. Thus, managers should take into account investors' reaction when they design marketing communication messages for reducing the cost of capital. Second, this study shows a channel on how marketing creates shareholder value and highlights the accountability of marketing. In addition to the direct impact of marketing on firm value, an indirect channel by reducing information asymmetry should be considered. Potentially, marketing managers can justify their spending from the perspective of increasing long-term shareholder value.

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Dispersion of Rayleigh Waves in the Korean Peninsula

  • Cho, Kwang-Hyun;Lee, Kie-Hwa
    • Journal of the Korean Geophysical Society
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    • v.9 no.3
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    • pp.231-240
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    • 2006
  • The crustal structure of the Korean Peninsula was investigated by analyzing phase velocity dispersion data of Rayleigh waves. Earthquakes recorded by three component broad-band velocity seismographs during 1999-2004 in South Korea were used in this study. The fundamental mode Rayleigh waves were extracted from vertical components of seismograms by multiple filter technique and phase match filter method. Phase velocity dispersion curves of the fundamental mode signal pairs for 14 surface wave propagation paths on the great circle in the range 10 to 80 sec were computed by two-station method. Treating the shear velocity of each layer as an independent parameter, phase velocity data of Rayleigh wave were inverted. All the result models can be explained by a rather homogeneous crust of shear-wave velocity increasing from 2.8 to 3.25 km/sec from top to about 33 km depth without any distinctive crustal discontinuities and an uppermost mantle of shear-wave velocity between 4.55 and 4.67 km/sec. Our results turn out to agree well with recent study of Cho et al. (2006 b) based on the analysis of seismic background noises to recover short-period (0.5-20 sec) Rayleigh- and Love-wave group velocity dispersion characteristics.

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Color Dispersion as an Indicator of Stellar Population Complexity for Galaxies in Clusters

  • Lee, Joon Hyeop;Pak, Mina;Lee, Hye-Ran;Oh, Sree
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.2
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    • pp.34.1-34.1
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    • 2018
  • We investigate the properties of bright galaxies with various morphological types in Abell 1139 and Abell 2589, using the pixel color-magnitude diagram (pCMD) analysis. The 32 bright member galaxies ($Mr{\leq}-21.3mag$) are deeply imaged in the g and r bands in our CFHT/MegaCam observations, as a part of the KASI-Yonsei Deep Imaging Survey of Clusters (KYDISC). We examine how the features of their pCMDs depend on galaxy morphology and infrared color. We find that the g - r color dispersion as a function of surface brightness (${\mu}r$) shows better performance in distinguishing galaxy morphology, than the mean g - r color does. The best set of parameters for galaxy classification appears to be a combination of the minimum color dispersion at ${\mu}r{\leq}21.2mag\;arcsec-2$ and the maximum color dispersion at $20.0{\leq}{\mu}r{\leq}21.0mag\;arcsec-2$: the latter reflects the complexity of stellar populations at the disk component in a typical spiral galaxy. Moreover, the color dispersion of an elliptical galaxy appears to be correlated with its WISE infrared color ([4.6]-[12]). This indicates that the complexity of stellar populations in an elliptical galaxy is related to its recent star formation activities. From this observational evidence, we infer that gas-rich minor mergers or gas interactions may have usually occurred during the recent growth of massive elliptical galaxies.

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Analysis on ESD Properties of the PANI added PU/MWNT Films (PANI 첨가 PU/MWNT 필름의 정전방전특성)

  • Ma, Hye Young;Yang, Sung Yong;Kim, Seung Jin
    • Textile Coloration and Finishing
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    • v.25 no.1
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    • pp.37-46
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    • 2013
  • This paper surveys the ESD characteristics of the PANI added PU/MWNT film according to the manufacturing conditions such as variation of the loading contents of PANI and the mixture ratio of 2 dispersion solutions. For this purpose, PANI added PU/MWNT ground films were made with IPA/MWNT 3wt% dispersion solution and PANI/DMF dispersion solutions(5, 10, 15, 20, 25, and 30wt% contents of the PANI) by the mixture ratio of dispersion solution(10/50, 20/40, 30/30, 40/20, and 50/10part) in the PU (972DF) 100g, which was treated with 500rpm for 30min in the stirrer with condition of the dry temperature $120^{\circ}C$ for 2min. Totally, 36 kinds of PANI added PU/MWNT film specimens were prepared. The physical properties of the PANI added PU/MWNT films such as electrical resistivity, absorbancy by UV-Vis spectrometer, and triboelectricity were measured and discussed with surface characteristics of the PANI added PU/MWNT films by SEM. The dispersion property of PANI to the DMF showed best dispersion at the 25% of PANI content. The surface electrical resistivity of the PANI added PU/MWNT films was decreased with increasing the weight content of PANI/DMF dispersion solution, and it showed the lowest value $10^6{\Omega}$ at the mixing condition of PANI/DMF 20part and MWNT/IPA 40part with 30% PANI. Furthermore, it was shown that the electrical and physical properties of the PANI added PU/MWNT film such as electrical resistivity, and triboelectricity were better than those of PU/MWNT film prepared with no PANI, which was result obtained in previous paper.

Analysis of Longitudinal Dispersion Coefficient : Part I. Comparative Study of Existing Equations for Dispersion Coefficient (종확산계수에 관한 연구 : I. 기존 종확산계수 추정식 비교)

  • 서일원;정태성
    • Water for future
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    • v.28 no.3
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    • pp.205-216
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    • 1995
  • Existing equations for dispersion coefficient are analyzed in depth to select proper dispersion coefficient which can represent dispersion characteristics of natural streams. Several equations are tested with measured data which were collected in 26 streams in the United States. Findings of this study are as follows. Elder's equation should not be used to estimate dispersion coefficient of the one-dimensional dispersion model because it underestimates significantly. McQuivey and Keefer's equation is overestimating, whereas Magazine et al.'s equation is underestimating. However, Iwasa and Aya's equation predicts relatively well. Fischer's equation is generally overestimating. Liu's equation predicts quite well. The performance of Liu's equation is the best of all especially in terms of accuracy. However, Liu's equation is generally overestimating in case of large river because the square of channel width is included in the equation. Therefore, it is recommended not to use Liu's equation in case of large rivers, especially rivers of which channel width is larger than 200m.

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Analysis of Stability Condition and Wideband Characteristics of 3D Isotropic Dispersion(ID)-FDTD Algorithm (3차원 ID-FDTD 알고리즘의 Stability Condition과 광대역 특성 분석)

  • Kim, Woo-Tae;Koh, Il-Suek;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.4
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    • pp.407-415
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    • 2011
  • The stability condition and wideband characteristics of 3D ID-FDTD algorithm which has low dispersion error with isotropic dispersion are presented in this paper. 3D ID-FDTD method was proposed to improve the defect of the Yee FDTD such as the anisotropy and large dispersion error. The published paper calculated the stability condition of 3D ID-FDTD algorithm by using numerical method, however, it is thought that the examples were not sufficient to verify the stability condition. Thus, in this paper, various simulations are included in order to hold reliability under the conditions that the plane wave propagation is assumed with a single frequency and a wideband frequency. Also, the 3D ID-FDTD algorithm is compared to those that have the similar FDTD algorithm with ID-FDTD such as Forgy's method and non-standard FDTD method in a wideband. Finally, the radar cross section(RCS) for the large sphere with high dielectric constant is calculated.

A Dispersion Analysis for Minimum Grids in the Frequency Domain Acoustic Wave Equation (주파수영역 음향 파동방정식에서 최소 격자수 결정을 위한 격자분산 분석)

  • Jang Seong-Hyung;Shin Chang-Soo;Yoon Kwang-Jin;Suh Sang-Young;Shin Sung-Ryul
    • Geophysics and Geophysical Exploration
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    • v.3 no.2
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    • pp.39-47
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    • 2000
  • A great deal of computing time and a large computer memory are needed to solve wave equation in a large complex subsurface layers using the finite difference method. The computing time and memory can be reduced by decreasing the number of grid points per minimum wave length. However, the decrease of grids may cause numerical dispersion and poor accuracy. In this study we performed the grid dispersion analysis for several rotated finite difference operators, which was commonly used to reduce grids per wavelength with accuracy in order to determine the solution for the acoustic wave equation in frequency domain. The rotated finite difference operators were to be extended to 81, 121 and 169 difference stars and studied whether the minimum grids could be reduced to 2 or not. To obtain accuracy (numerical errors less than $1\%$) the following was required: more than 13 grids for conventional 5 point difference stars, 9 grids for 9 difference stars, 3 grids for 25 difference stars, and 2.7 grids for 49 difference stars. After grid dispersion analysis for the new rotated finite difference operators, more than 2.5 grids for 81 difference stars, 2.3 grids for 121 difference stars and 2.1 grids for 169 difference stars were needed. However, in the 169 difference stars, there was no solution because of oscillation of the dispersion curves in the group velocity curves. This indicated that the grids couldn't be reduced to 2 in the frequency acoustic wave equation. According to grid dispersion analysis for the determination of grid points, the more rotated finite difference operators, the fewer grid points. However, the more rotated finite difference operators that are used, the more complex the difference equation terms.

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Analysis of Shallow Water Flow in Curved Channel Using Dispersion Stresses Method (분산응력법을 이용한 곡선수로에서의 천수흐름 해석)

  • Song, Chang Geun;Seo, Il Won;Kim, Tae Won;Ahn, Jungkyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.5
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    • pp.1785-1795
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    • 2013
  • Most of the previous models for analysis of shallow water flow assumed the uniform velocity distributions over the flow depth so that they produced incorrect velocity prediction at meandering part due to the ignorance of secondary current. In this study, the vertical velocity profiles in longitudinal and transverse direction were decomposed as the mean and variation components, which resulted in additional dispersion stresses terms in momentum equations. The proposed model were applied at the channels with $30^{\circ}$, $90^{\circ}$, $270^{\circ}$ bends, and shallow water flow in curved channel was analyzed using dispersion stresses. The dispersion stresses acted as a sink or source in the momentum equations, which caused the transverse convection of momentum to shift from the inner bank to the outer bank.

Numerical Analysis for Improving of SOx Removal Efficiency in the DSI(Dry Sorbent Injection Technique) of FGD System(I) (배연탈황 공정 중 DSI 공법의 탈황효율 향상을 위한 전산 유체 역학적 연구(I))

  • Chung, Jin-Do;Kim, Jang-Woo;Kim, Byung-Hwan;Park, Young-Moon
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.1
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    • pp.47-53
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    • 2007
  • The aim of this study is to research applicable possibility or Dry Sorbent Injection Technique(DSI) in sox removal process using Computational Fluid Dynamics(CFD) software package. It will be applied for 500MW in capacity coal-fired thermal power plant operated by South Korea N. Power Co., Ltd. The DSI process is adapted between a preheater and an EP process in the technological assembly. The numerical analysis performs in predicting and optimizing of DSI process's characteristics, which consists of structure of duct, position of injection nozzles, injection speed, and dispersion of sorbent. Computing results are shown that degree of sorbent dispersion depends on structure of duct and position of injection nozzles strongly. The highest dispersion efficiency was obtained when we set a Lobed-plate inside the duct and 6 injection nozzles on the duct(4 injection nozzles at the corners and 2 injection nozzles on upper and under walls as a rectangle duct shape). We also know that change of injection speed of sorbent doesn't have an large effect on the sorbent dispersion but it can effect to drop pressure.