• Title/Summary/Keyword: 가우스 함수

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지자기 전달함수의 로버스트 추정

  • Yang, Jun-Mo;O, Seok-Hun;Lee, Deok-Gi;Yun, Yong-Hun
    • Journal of the Korean Geophysical Society
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    • v.5 no.2
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    • pp.131-142
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    • 2002
  • Geomagnetic transfer function is generally estimated by choosing transfer to minimize the square sum of differences between observed values. If the error structure sccords to the Gaussian distribution, standard least square(LS) can be the estimation. However, for non-Gaussian error distribution, the LS estimation can be severely biased and distorted. In this paper, the Gaussian error assumption was tested by Q-Q(Quantile-Quantile) plot which provided information of real error structure. Therefore, robust estimation such as regression M-estimate that does not allow a few bad points to dominate the estimate was applied for error structure with non-Gaussian distribution. The results indicate that the performance of robust estimation is similar to the one of LS estimation for Gaussian error distribution, whereas the robust estimation yields more reliable and smooth transfer function estimates than standard LS for non-Gaussian error distribution.

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Threshold Voltage Shift for Doping Profile of Asymmetric Double Gate MOSFET (도핑분포함수에 따른 비대칭 이중게이트 MOSFET의 문턱전압이동현상)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.4
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    • pp.903-908
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    • 2015
  • This paper has analyzed threshold voltage shift for doping profile of asymmetric double gate(DG) MOSFET. Ion implantation is usually used in process of doping for semiconductor device and doping profile becomes Gaussian distribution. Gaussian distribution function is changed for projected range and standard projected deviation, and influenced on transport characteristics. Therefore, doping profile in channel of asymmetric DGMOSFET is affected in threshold voltage. Threshold voltage is minimum gate voltage to operate transistor, and defined as top gate voltage when drain current is $0.1{\mu}A$ per unit width. The analytical potential distribution of series form is derived from Poisson's equation to obtain threshold voltage. As a result, threshold voltage is greatly changed by doping profile in high doping range, and the shift of threshold voltage due to projected range and standard projected deviation significantly appears for bottom gate voltage in the region of high doping concentration.

Subthreshold Characteristics of Double Gate MOSFET for Gaussian Function Distribution (도핑분포함수의 형태에 따른 DGMOSFET의 문턱전압이하특성)

  • Jung, Hak-Kee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.6
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    • pp.1260-1265
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    • 2012
  • This paper have presented the change for subthreshold characteristics for double gate(DG) MOSFET based on scaling theory and the shape of Gaussian function. To obtain the analytical solution of Poisson's equation, Gaussian function been used as carrier distribution and consequently potential distributions have been analyzed closely for experimental results, and the subthreshold characteristics have been analyzed for the shape parameters of Gaussian function such as projected range and standard projected deviation. Since this potential model has been verified in the previous papers, we have used this model to analyze the subthreshold chatacteristics. The scaling theory is to sustain constant outputs for the change of device parameters. As a result to apply the scaling theory for DGMOSFET, we know the subthreshold characteristics have been greatly changed, and the change of threshold voltage is bigger relatively.

A Linear System Approach to Serving Gaussian Traffic in Packet-Switching Networks (패킷 교환망에서 가우스 분포 트래픽을 서비스하는 선형 시스템 접근법)

  • Chong, Song;Shin, Min-Su;Chong, Hyun-Hee
    • Journal of KIISE:Information Networking
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    • v.29 no.5
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    • pp.553-561
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    • 2002
  • We present a novel service discipline, called linear service discipline, to serve multiple QoS queues sharing a resource and analyze its properties. The linear server makes the output traffic and the queueing dynamics of individual queues as a linear function of its input traffic. In particular, if input traffic is Gaussian, the distributions of queue length and output traffic are also Gaussian with their mean and variance being a function of input mean and input power spectrum (equivalently, autocorrelation function of input). Important QoS measures including buffer overflow probability and queueing delay distribution are also expressed as a function of input mean and input power spectrum. This study explores a new direction for network-wide traffic management based on linear system theories by letting us view the queueing process at each node as a linear filter.

Measurement-based Face Rendering reflecting Positional Scattering Properties (위치별 산란특성을 반영한 측정기반 얼굴 렌더링)

  • Park, Sun-Yong;Oh, Kyoung-Su
    • Journal of Korea Game Society
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    • v.9 no.5
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    • pp.137-144
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    • 2009
  • This paper predicts 6 facial regions that may have sharply different scattering properties, rendering the face more realistically based on their diffusion profiles. The scattering properties are acquired in the form of high dynamic range by photographing the pattern formed around an unit ray incident on facial skin. The acquired data are fitted to a 'linear combination of Gaussian functions', which well approximates the original diffusion profile of skin and has good characteristics as the filter. During the process, to prevent its solutions from converging into local minima, we take advantage of the genetic algorithm to set up the initial value. Each Gaussian term is applied to the irradiance map as a filter, expressing subsurface scattering effect. In this paper, to efficiently handle the maximum 12 Gaussian filterings, we make use of the parallel capacity of CUDA.

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Microstructure Generation and Linearly Elastic Characteristic Analysis of Hierarchical Models for Dual-Phase Composite Materials (이종 입자복합재의 미세구조 생성과 계층적 모델의 선형 탄성적 응답특성 해석)

  • Cho, Jin-Rae
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.3
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    • pp.133-140
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    • 2018
  • This paper is concerned with the 2-D micostructure generation for $Ni-A{\ell}_2O_3$ dual-phase composite materials and the numerical analysis of mechanical characteristic of hierarchical models of microstructure which are defined in terms of the scale of microstructure. The microstructures of dual-phase composite materials were generated by applying the mathematical RMDF(random morphology description functions) technique to a 2-D RVE of composite materials. And, the hierarchical models of microstructure were defined by the number of Gaussian points. Meanwhile, the volume fractions of metal and ceramic particles were set by adjusting the level of RMD functions. The microstructures which were generated by RMDF technique are definitely random even though the total number of Gaussian points is the same. The randomly generated microstructures were applied to a 2-D beam model, and the variation of normal and shear stresses to the scale of microstructure was numerically investigated. In addition, through the crack analyses, the influence of RMDF randomness and Gauss point number on the crack-tip stress is investigated.

Non-linear phenomenon adjacent to focal plane within the focused fields diffracted by a straight edge (직선 edge에 의해 회절된 초음파 집속음장의 초점부근에서의 비선형 현상)

  • 김정순
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1998.06e
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    • pp.243-246
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    • 1998
  • 집속음장의 고조파성분을 이용한 초음파영상의 특성을 해석하기 위해 집속된 가우스 음원에 직선 edge를 초점면 및 초점면의 전, 후방에 삽입하여 edge의 후방에서 생성되는 음장을 조사하였다. 계산에서는 그린함수의 간단화를 위해 Fresnel근사를 이용하였고, 실험에서는 성형전극을 형성시킨 1.9MHz 요면진동자에 의한 가우스분포의 음장을 갖는 초음파빔에 수직하게 edge를 삽입시켰다. 음장의 이론해석 및 실험결과, 초점면의 제2고조파의 빔형상을 제외하고는 계산치와 실험치가 잘 일치하고 있으며, 제2고조파의 공간 분해능이 기본파에 비해 높음을 알았다.

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Nonlinear phenomena in the focused fields diffracted by a straight edge (직선 edge 에 의해 회절된 집속음장내에서의 비선형 현상)

  • 김정순
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1998.06d
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    • pp.13-17
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    • 1998
  • 집속음장이 고조파성분을 이용한 초음파영상의 특성을 해석하는 초기단계로서 음축에 수직하게 놓인 강체판의 직선 edge가 집속 가우스빔을 회절시킨다고 가정하고, edge의 전후에서 발생하는 제 2고조파를 고려해서 회절음장을 해석하였다. 계산에서는 그린함수의 간단화를 위해 , Fresnel 근사를 이용하였고 실험에서는 성형전극을 형성시킨 요면 압전진동자에 의한 1.9MHz 집속가우스음원에 의해 만들어지는 초음파 빔에 수직하게 edge을 삽입시켰다. 회절 edge 후방에서 음장을 관측한 결과, 제 2고조파의 빔형상을 제외하고는 계산치와 실험치가 잘 일치하고 있다.

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Stability Analysis of Nonlinear Pulse-Modulated System Subject to Gaussian Noise (가우스 잡음을 고려한 비선형 펄스 변조 시스템의 안정도 분석)

  • 강영채
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.19 no.6
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    • pp.67-79
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    • 1982
  • The stability of general pulse-width modulation system with Gaussian random disturbance was discussed . General system is divided into nonlinear and linear elements using the conventional describing function method. The concept of the equivalent admittance was used to find the transfer characteristic of the nonlinear element of the system. In this paper the self-sustained oscillation condition in the autonomous system was derived and the results was analyzed with computer simulation.

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Performance of DS/SSMA communication systems over frequency selective rician fading channels with gaussian and impulsive noise (가우스 잡음과 임펄스 잡음이 혼합된 주파수 선택적 리시안 페이딩 채널에서 DS/SSMA 통신시스템의 성능분석)

  • 진익수;안재영;이동도;황금찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.461-470
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    • 1996
  • In this paper, the average probability of bit error of direct sequence spread spectrum multiple access (DS/SSMA) communication system is derived over frequency-selective rician fading channels with Gaussian and impulsive noise. Multiple access interference due to K asynchronous users transmitting simultaneously is computed using the characteristic function method, and compared with Gaussian approximation.

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