• Title/Summary/Keyword: Point kernel

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Nonparametric detection algorithm of discontinuity points in the variance function

  • Huh, Jib
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.3
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    • pp.669-678
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    • 2007
  • An algorithm to detect the number of discontinuity points of the variance function in regression model is proposed. The proposed algorithm is based on the left and right one-sided kernel estimators of the second moment function and test statistics of the existence of a discontinuity point coming from the asymptotic distribution of the estimated jump size. The finite sample performance is illustrated by simulated example.

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Analysis on a Simple Waveguide Using Meshfree Method (무요소법을 이용한 waveguide 내의 필드 분포 해석)

  • Lee, Chany;Woo, Dong-Kyun;Jung, Hyun-Kyo
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.190-192
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    • 2008
  • This paper shows the formulation of fast moving least square reproducing kernel method (FMLSRKM) which is a kind of meshfree methods. FMLSRKM has some advantages compared to conventional numerical techniques such as finite element method. For simple analysis on a rectangular waveguide, point collocation scheme is introduced and applied.

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NONPARAMETRIC ESTIMATION OF THE VARIANCE FUNCTION WITH A CHANGE POINT

  • Kang Kee-Hoon;Huh Jib
    • Journal of the Korean Statistical Society
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    • v.35 no.1
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    • pp.1-23
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    • 2006
  • In this paper we consider an estimation of the discontinuous variance function in nonparametric heteroscedastic random design regression model. We first propose estimators of the change point in the variance function and then construct an estimator of the entire variance function. We examine the rates of convergence of these estimators and give results for their asymptotics. Numerical work reveals that using the proposed change point analysis in the variance function estimation is quite effective.

A Protection Technique for Kernel Functions under the Windows Operating System (윈도우즈 운영체제 기반 커널 함수 보호 기법)

  • Back, Dusung;Pyun, Kihyun
    • Journal of Internet Computing and Services
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    • v.15 no.5
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    • pp.133-139
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    • 2014
  • Recently the Microsoft Windows OS(operating system) is widely used for the internet banking, games etc. The kernel functions provided by the Windows OS can perform memory accesses, keyboard input/output inspection, and graphics output of any processes. Thus, many hacking programs utilizes those for memory hacking, keyboard hacking, and making illegal automation tools for game programs. Existing protection mechanisms make decisions for existence of hacking programs by inspecting some kernel data structures and the initial parts of kernel functions. In this paper, we point out drawbacks of existing methods and propose a new solution. Our method can remedy those by modifying the system service dispatcher code. If the dispatcher code is utilized by a hacking program, existing protection methods cannot detect illegal operations. Thus, we suggest that protection methods should investigate the modification of the dispatcher code as well as kernel data structures and the initial parts of kernel functions.

The Study on Application of Regional Frequency Analysis using Kernel Density Function (핵밀도 함수를 이용한 지역빈도해석의 적용에 관한 연구)

  • Oh, Tae-Suk;Kim, Jong-Suk;Moon, Young-Il;Yoo, Seung-Yeon
    • Journal of Korea Water Resources Association
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    • v.39 no.10 s.171
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    • pp.891-904
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    • 2006
  • The estimation of the probability precipitation is essential for the design of hydrologic projects. The techniques to calculate the probability precipitation can be determined by the point frequency analysis and the regional frequency analysis. The regional frequency analysis includes index-flood technique and L-moment technique. In the regional frequency analysis, even if the rainfall data passed homogeneity, suitable distributions can be different at each point. However, the regional frequency analysis can supplement the lacking precipitation data. Therefore, the regional frequency analysis has weaknesses compared to parametric point frequency analysis because of suppositions about probability distributions. Therefore, this paper applies kernel density function to precipitation data so that homogeneity is defined. In this paper, The data from 16 rainfall observatories were collected and managed by the Korea Meteorological Administration to achieve the point frequency analysis and the regional frequency analysis. The point frequency analysis applies parametric technique and nonparametric technique, and the regional frequency analysis applies index-flood techniques and L-moment techniques. Also, the probability precipitation was calculated by the regional frequency analysis using variable kernel density function.

Estimation of Probability Precipitation by Regional Frequency Analysis using Cluster analysis and Variable Kernel Density Function (군집분석과 변동핵밀도함수를 이용한 지역빈도해석의 확률강우량 산정)

  • Oh, Tae Suk;Moon, Young-Il;Oh, Keun-Taek
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.2B
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    • pp.225-236
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    • 2008
  • The techniques to calculate the probability precipitation for the design of hydrological projects can be determined by the point frequency analysis and the regional frequency analysis. Probability precipitation usually calculated by point frequency analysis using rainfall data that is observed in rainfall observatory which is situated in the basin. Therefore, Probability precipitation through point frequency analysis need observed rainfall data for enough periods. But, lacking precipitation data can be calculated to wrong parameters. Consequently, the regional frequency analysis can supplement the lacking precipitation data. Therefore, the regional frequency analysis has weaknesses compared to point frequency analysis because of suppositions about probability distributions. In this paper, rainfall observatory in Korea did grouping by cluster analysis using position of timely precipitation observatory and characteristic time rainfall. Discordancy and heterogeneity measures verified the grouping precipitation observatory by the cluster analysis. So, there divided rainfall observatory in Korea to 6 areas, and the regional frequency analysis applies index-flood techniques and L-moment techniques. Also, the probability precipitation was calculated by the regional frequency analysis using variable kernel density function. At the results, the regional frequency analysis of the variable kernel function can utilize for decision difficulty of suitable probability distribution in other methods.

Estimation of the number of discontinuity points based on likelihood (가능도함수를 이용한 불연속점 수의 추정)

  • Huh, Jib
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.1
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    • pp.51-59
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    • 2010
  • In the case that the regression function has a discontinuity point in generalized linear model, Huh (2009) estimated the location and jump size using the log-likelihood weighted the one-sided kernel function. In this paper, we consider estimation of the unknown number of the discontinuity points in the regression function. The proposed algorithm is based on testing of the existence of a discontinuity point coming from the asymptotic distribution of the estimated jump size described in Huh (2009). The finite sample performance is illustrated by simulated example.

DEVELOPMENT OF POINT KERNEL SHIELDING ANALYSIS COMPUTER PROGRAM IMPLEMENTING RECENT NUCLEAR DATA AND GRAPHIC USER INTERFACES

  • Kang, Sang-Ho;Lee, Seung-Gi;Chung, Chan-Young;Lee, Choon-Sik;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.215-224
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    • 2001
  • In order to comply with revised national regulationson radiological protection and to implement recent nuclear data and dose conversion factors, KOPEC developed a new point kernel gamma and beta ray shielding analysis computer program. This new code, named VisualShield, adopted mass attenuation coefficient and buildup factors from recent ANSI/ANS standards and flux-to-dose conversion factors from the International Commission on Radiological Protection (ICRP) Publication 74 for estimation of effective/equivalent dose recommended in ICRP 60. VisualShieid utilizes graphical user interfaces and 3-D visualization of the geometric configuration for preparing input data sets and analyzing results, which leads users to error free processing with visual effects. Code validation and data analysis were performed by comparing the results of various calculations to the data outputs of previous programs such as MCNP 4B, ISOSHLD-II, QAD-CGGP, etc.

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Identification of Volterra Kernels of Nonlinear Van do Vusse Reactor

  • Kashiwagi, Hiroshi;Rong, Li
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.2
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    • pp.109-113
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    • 2002
  • Van de Vusse reactor is known as a highly nonlinear chemical process and has been considered by a number of researchers as a benchmark problem for nonlinear chemical process. Various identification methods for nonlinear system are also verified by applying these methods to Van de Vusse reactor. From the point of view of identification, only the Volterra kernel of second order has been obtained until now. In this paper, the authors show that Volterra kernels of nonlinear Van de Vusse reactor of up to 3rd order are obtained by use of M-sequence correlation method. A pseudo-random M-sequence is applied to Van de Vusse reactor as an input and its output is measured. Taking the crosscorrelation function between the input and the output, we obtain up to 3rd order Volterra kernels, which is the highest order Volterra kernel obtained until now for Van de Vusse reactor. Computer simulations show that when Van de Vusse chemical process is identified by use of up to 3rd order Volterra kernels, a good agreement is observed between the calculated output and the actual output.

Use of Support Vector Machines in Biped Humanoid Robot for Stable Walking (안정적인 보행을 위한 이족 휴머노이드 로봇에서의 서포트 벡터 머신 이용)

  • Kim Dong-Won;Park Gwi-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.4
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    • pp.315-319
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    • 2006
  • Support vector machines in biped humanoid robot are presented in this paper. The trajectory of the ZMP in biped walking robot poses an important criterion for the balance of the walking robots but complex dynamics involved make robot control difficult. We are establishing empirical relationships based on the dynamic stability of motion using SVMs. SVMs and kernel method have become very popular method for learning from examples. We applied SVM to model the practical humanoid robot. Three kinds of kernels are employed also and each result has been compared. As a result, SVM based on kernel method have been found to work well. Especially SVM with RBF kernel function provides the best results. The simulation results show that the generated ZMP from the SVM can be improve the stability of the biped walking robot and it can be effectively used to model and control practical biped walking robot.