• Title/Summary/Keyword: Gaussian field

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Sound Transmission Loss of Double Panels(I) : A Double Wall with Air Cavity (이중판의 차음손실 I)

  • 강현주;김현실;김재승;김상렬
    • Journal of KSNVE
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    • v.7 no.6
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    • pp.945-952
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    • 1997
  • This paper shows the feasibility of the suggestion that the angle distribution of incident sound to panels might be gaussian, instead of the conventional uniform distribution in the analysis of transmission loss of panels. To prove the suggestion, the problems with the diffuse sound field in a reverberation room are examined by case studies and the comparision of the prediction with the measurement of sound transmission loss of walls are performed. The results of the comparision show good agreement between the two values.

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The acceleration of microscopic particles in the near field diffracted from the fiber end (광섬유의 Near field를 이용한 미세입자의 가속에 관한 연구)

  • Kang, Yong-Hoon;Lee, Hyuk
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.359-361
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    • 1993
  • The force exerted on particles when the momentum of light is changed at the boundary is used in accelerating particles in the fluid. So far, particles are accelerated by the gaussian beam focused by lenses or microscopic objectives. In this paper, particles arc moved by the light diffracted from the fiber end. And we proposed the possibility of particle acceleration using the fiber end.

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Wavelet Smoothing을 이용한 MRI 데이터에서의 Intensity Non-uniformity 보정

  • 김양현;류완석;정성택
    • Proceedings of the KSMRM Conference
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    • 2003.10a
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    • pp.75-75
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    • 2003
  • 목적: MR 영상에 나타나는 bias field, 즉 영상의 특정 부분이 주위보다 어둡거나 밝게 나타나는 현상을 보다 균일하게 보정시키는 방법으로 제시된 N3 방법에서 Gaussian kernel을 사용한 smoothing 방법 대신에 Wavelet(Daubechies, D4)함수를 smoothing기법으로 사용했을 때 어느 정도 균일함에 향상이 일어나는지를 알아보는 것이다.

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Characterization of Channel Electric Field in LDD MOSFET (LDD MOSFET채널 전계의 특성 해석)

  • 한민구;박민형
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.38 no.6
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    • pp.401-415
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    • 1989
  • A simple but accurate analytical model for the lateral channel electric field in gate-offset structured Lightly Doped Drain MOSFET has been developed. Our model assumes Gaussian doping profile, rather than simple uniform doping, for the lightly doped region and our model can be applied to LDD structures where the junction depth of LDD is not identical to the heavily doped drain. The validity of our model has been proved by comparing our analytical results with two dimensional device simulations. Due to its simplicity, our model gives a better understanding of the mechanisms involved in reducing the electric field in the LDD MOSFET. The model shows clearly the dependencies of the lateral channel electric field on the drain and gate bias conditions and process, design parameters. Advantages of our analytical model over costly 2-D device simulations is to identify the effects of various parameters, such as oxide thickness, junction depth, gate/drain bias, the length and doping concentration of the lightly doped region, on the peak electric field that causes hot-electron pohenomena, individually. Our model can also find the optimum doping concentration of LDD which minimizes the peak electric field and hot-electron effects.

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VLSI Architecture for High Speed Implementation of Elliptic Curve Cryptographic Systems (타원곡선 암호 시스템의 고속 구현을 위한 VLSI 구조)

  • Kim, Chang-Hoon
    • The KIPS Transactions:PartC
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    • v.15C no.2
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    • pp.133-140
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    • 2008
  • In this paper, we propose a high performance elliptic curve cryptographic processor over $GF(2^{163})$. The proposed architecture is based on a modified Lopez-Dahab elliptic curve point multiplication algorithm and uses Gaussian normal basis for $GF(2^{163})$ field arithmetic. To achieve a high throughput rates, we design two new word-level arithmetic units over $GF(2^{163})$ and derive a parallelized elliptic curve point doubling and point addition algorithm with uniform addressing based on the Lopez-Dahab method. We implement our design using Xilinx XC4VLX80 FPGA device which uses 24,263 slices and has a maximum frequency of 143MHz. Our design is roughly 4.8 times faster with 2 times increased hardware complexity compared with the previous hardware implementation proposed by Shu. et. al. Therefore, the proposed elliptic curve cryptographic processor is well suited to elliptic curve cryptosystems requiring high throughput rates such as network processors and web servers.

Study of Polymor Properties Prediction Using Nonlinear SEM Based on Gaussian Process Regression (가우시안 프로세서 회귀 기반의 비선형 구조방정식을 활용한 고분자 물성거동 예측 연구)

  • Moon Kyung-Yeol;Park Kun-Wook
    • KIPS Transactions on Computer and Communication Systems
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    • v.13 no.1
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    • pp.1-9
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    • 2024
  • In the development and mass production of polymers, there are many uncontrollable variables. Even small changes in chemical composition, structure, and processing conditions can lead to large variations in properties. Therefore, Traditional linear modeling techniques that assume a general environment often produce significant errors when applied to field data. In this study, we propose a new modeling method (GPR-SEM) that combines Structural Equation Modeling (SEM) and Gaussian Process Regression (GPR) to study the Friction-Coefficient and Flexural-Strength properties of Polyacetal resin, an engineering plastic, in order to meet the recent trend of using plastics in industrial drive components. And we also consider the possibility of using it for materials modeling with nonlinearity.

Initial Mixing Analysis of Ocean Outfalls Discharged into Density Stratified Flowing Ambients (밀도성층화된 흐름수역으로 방류되는 해양방류관의 초기확산해석)

  • Lee, Jae-Hyeong;Seo, Il-Won
    • Journal of Korea Water Resources Association
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    • v.33 no.2
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    • pp.207-217
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    • 2000
  • A numerical model is applied to analyze the mixing characteristics of an axisymmetric turbulent buoyant jet discharged into flowing stratified ambients. The numerical model is a Gaussian-vortex model which incorporates the effects of the vortex pair known as the representative characteristics of far-field in flowing ambients. Six ocean outfalls that have field data for the initial dilution at the water surface are selected for testing the applicability of the developed numerical model. The comparisons of the observed initial dilutions and the simulated ones show that the developed numerical model could be used for the analyses of the initial mixings induced by the sewage diffuser discharged into the ocean.

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An EM Algorithm-Based Approach for Imputation of Pixel Values in Color Image (색조영상에서 랜덤결측화소값 대체를 위한 EM 알고리즘 기반 기법)

  • Kim, Seung-Gu
    • The Korean Journal of Applied Statistics
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    • v.23 no.2
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    • pp.305-315
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    • 2010
  • In this paper, a frequentistic approach to impute the values of R, G, B-components in random missing pixels of color image is provided. Under assumption that the given image is a realization of Gaussian Markov random field, its model is designed such that each neighbor pixel values for a given pixel follows (independently) the normal distribution with covariance matrix scaled by an evaluates of the similarity between two pixel values, so that the imputation is not to be affected by the neighbors with different color. An approximate EM-based algorithm maximizing the underlying likelihood is implemented to estimate the parameters and to impute the missing pixel values. Some experiments are presented to show its effectiveness through performance comparison with a popular interpolation method.

Nonlinear refractive index measurement for amorphous $As_2S_3$ thin film by Z-scan method (Z-scan 방법에 의한 비정질 $As_2S_3$ 박막의 비선형 굴절률 측정)

  • 김성규;이영락;곽종훈;최옥식;이윤우;송재봉;서호형;이일항
    • Korean Journal of Optics and Photonics
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    • v.9 no.5
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    • pp.342-347
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    • 1998
  • We present a theoretical analysis of Gaussian beam propagation in nonlinear Kerr media by using aberration-free approximation and Huygens-Fresnel diffraction integral and obtain a simple analytic formular for Z-scan characteristics. Z-scan experiments are carried out on amorphous $As_2S_3$ thin film and compared with the theory developed, showing good agreement. The sign and the value of ${\gamma}$ have been measured at 633 nm to be $+8.65{\times}10^{-6}\textrm{cm}^2/W$. We also measured the far-field intensity profiles, which confirm again self-focusing effect.

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