• 한국임상보건과학회지
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• 제4권4호
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• pp.756-761
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• 2016

Purpose. Noise occurs at measuring Electoretinogram(ERG) signals as the other bio-signal measurement. It is compared the denoising performance according to the mother function of wavelet transforms. Methods. The ERG signal that generated power supply noise and white noise was used as a sampling signal. The noise of ERG signal was filtered by using haar, db7, bior mother function. The filtering performance of each mother functions was compared using Fourier transform spectrum and SNR(signal to noise ratio). Results. In the haar functioin, the result of the Fourier transform spectrum was that the power supply noise is removed and the white noise performance is not good. The SNR was 27.0404. In the db7 function, the results of Fourier transform spectrum was that the power supply noise is removed and the white noise performance is good. The SNR was 35.1729. In the db7 function, the results of Fourier transform spectrum was that the power supply noise is removed and the white noise performance is the bset. The SNR was 35.4445. Conclusions. The db7, bior function was good results in power supply noise and white noise filtered. The bior function is suitable for filtering noise of the ERG signal.

• Structural Engineering and Mechanics
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• 제28권4호
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• pp.373-386
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• 2008

In this study stochastic analysis of non-linear dynamical systems under ${\alpha}$-stable, multiplicative white noise has been conducted. The analysis has dealt with a special class of ${\alpha}$-stable stochastic processes namely sub-Gaussian white noises. In this setting the governing equation either of the probability density function or of the characteristic function of the dynamical response may be obtained considering the dynamical system forced by a Gaussian white noise with an uncertain factor with ${\alpha}/2$- stable distribution. This consideration yields the probability density function or the characteristic function of the response by means of a simple integral involving the probability density function of the system under Gaussian white noise and the probability density function of the ${\alpha}/2$-stable random parameter. Some numerical applications have been reported assessing the reliability of the proposed formulation. Moreover a proper way to perform digital simulation of the sub-Gaussian ${\alpha}$-stable random process preventing dynamical systems from numerical overflows has been reported and discussed in detail.

• 호남수학학술지
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• 제20권1호
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• pp.97-109
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• 1998

We first obtain the white noise calculus to the computation of Feynman integral for a generalized function, according to the definition of Feynman integrals by T. Hida and L. Streit. We next give the translation theorem for Feynman integral of a generalized function.

• 대한수학회지
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• 제38권2호
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• pp.297-309
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• 2001

White noise distribution theory over the complex Gaussian space is established on the basis of the recently developed white noise operator theory. Unitarity condition for a white noise operator is discussed by means of the operator symbol and complex Gaussian integration. Concerning the overcompleteness of the exponential vectors, a coherent sate representation of a white noise function is uniquely specified from the diagonal coherent state representation of the associated multiplication operator.

• 한국엔터테인먼트산업학회논문지
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• 제13권6호
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• pp.265-275
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• 2019

본 연구는 지적장애 아동을 대상으로 백색소음을 적용하여 대상자들의 쓰기 능력과 손 기능의 변화를 분석하여 백색소음의 적용에 따른 지적장애 아동의 쓰기 능력과 손 기능 변화에 대한 기초자료를 제공하고자 수행되었다. 연구대상은 지적장애 아동 12명이며, 백색소음을 적용하여 대상자들의 적용 전, 후 쓰기 능력과 손 기능을 분석하였다. 백색소음의 제공은 백색소음 발생기를 통해 연속적이며, 균일하게 제공하였다. 쓰기 능력의 분석은 KNISE-BAAT(Korea National Institute for Special Education-Basic Academic Achievement Tests) 도구를 활용하여 표기능력, 어휘구사력, 문장구사력을 평가하였다. 손 기능의 분석은 Manual Function Test(MFT) 도구의 세부항목인 Pegboard 항목을 활용하여 분석하였다. 쓰기 능력 분석결과 대상자들의 표기능력과 어휘구사력에서 통계적으로 유의미한 향상이 나타났으며, 문장구사력에서는 향상이 나타나지 않았다. 손 기능 분석결과 양손 모두 통계적으로 유의미한 향상이 나타났다. 따라서, 지적장애 아동들의 저하된 쓰기 능력과 손 기능을 향상시킬 수 있는 보상적 접근방법으로 백색소음의 적용을 고려해야 할 필요가 있다고 판단되며, 지적장애 아동들의 수행수준과 학습수준, 학업성취도를 향상시킬 수 있도록 생활공간 및 학습공간에서 백색소음의 제공을 고려해야 할 것이다.

• Advances in nano research
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• 제5권1호
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• pp.13-25
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• 2017

We examine the total optical dielectric function (TODF) of impurity doped GaAs quantum dot (QD) from the viewpoint of anisotropy, position-dependent effective mass (PDEM) and position dependent dielectric screening function (PDDSF), both in presence and absence of noise. The dopant impurity potential is Gaussian in nature and noise employed is Gaussian white noise that has been applied to the doped system via two different modes; additive and multiplicative. A change from fixed effective mass and fixed dielectric constant to those which depend on the dopant coordinate manifestly affects TODF. Presence of noise and also its mode of application bring about more rich subtlety in the observed TODF profiles. The findings indicate promising scope of harnessing the TODF of doped QD systems through expedient control of site of dopant incorporation and application of noise in desired mode.

• Journal of the Korean Statistical Society
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• 제27권4호
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• pp.485-494
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• 1998

In the white noise model we construct an adaptive estimate for f(0) for a decreasing function f. We also show that the maximum mean square error of this estimate attains the same rate as the minimax risk simultaneously over a range of Lipschitz classes of order less than or equal to one.

• 대한수학회보
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• 제37권3호
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• pp.601-618
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• 2000

Let (and $g^*$) be the space of regular test (and generalized, resp.) white noise functions. The integral kernel operators acting on and transformation groups of operators on are studied, and then every integral kernel operator acting on can be extended to continuous linear operator on $g^*$. The existence and uniqueness of solutions of Cauchy problems associated with certain integral kernel operators with intial data in $g^*$ are investigated.

• 대한수학회논문집
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• 제14권2호
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• pp.329-336
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• 1999

We construct the Gelfand triple based on the space \ulcorner, introduced by Sato and di Silva, of analytic and exponentially decreasing function. This space denoted by(\ulcorner) of white noise test functionals are defined by the operator cosh \ulcorner, A=-(\ulcorner)\ulcorner+x\ulcorner+1. We also note that many properties like generalizations of the Paley-Wiener theorem and the Bochner-Schwartz theorem hold in this space as in the space of Hida distributions.

• Wind and Structures
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• 제16권2호
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• pp.157-178
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• 2013

Output-only modal parameter identification is based on the assumption that external forces on a linear structure are white noise. However, harmonic excitations are also often present in real structural vibrations. In particular, it has been realized that the use of forced acceleration responses without knowledge of external forces can pose a problem in the modal parameter identification, because an external force is imparted to its impulse acceleration response function. This paper provides a three-stage identification procedure as a solution to the problem of harmonic and white noise excitations in the acceleration responses of a linear dynamic system. This procedure combines the uses of the mode indicator function, the complex mode indication function, the enhanced frequency response function, an iterative rational fraction polynomial method and mode shape inspection for the correlation-related functions of the force-embedded acceleration responses. The procedure is verified via numerical simulation of a five-floor shear building and a two-dimensional frame and also applied to ambient vibration data of a large-span roof structure. Results show that the modal parameters of these dynamic systems can be satisfactorily identified under the requirement of wide separation between vibration modes and harmonic excitations.