• Title/Summary/Keyword: Sampling Theorem

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Convergence rate of a test statistics observed by the longitudinal data with long memory

  • Kim, Yoon Tae;Park, Hyun Suk
    • Communications for Statistical Applications and Methods
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    • v.24 no.5
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    • pp.481-492
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    • 2017
  • This paper investigates a convergence rate of a test statistics given by two scale sampling method based on $A\ddot{i}t$-Sahalia and Jacod (Annals of Statistics, 37, 184-222, 2009). This statistics tests for longitudinal data having the existence of long memory dependence driven by fractional Brownian motion with Hurst parameter $H{\in}(1/2,\;1)$. We obtain an upper bound in the Kolmogorov distance for normal approximation of this test statistic. As a main tool for our works, the recent results in Nourdin and Peccati (Probability Theory and Related Fields, 145, 75-118, 2009; Annals of Probability, 37, 2231-2261, 2009) will be used. These results are obtained by employing techniques based on the combination between Malliavin calculus and Stein's method for normal approximation.

Stability and a scheduling method for network-based control systems (네트워크를 이용한 제어 시스템의 안정도 및 스케줄링에 관한 연구)

  • 김용호;권욱현;박홍성
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1432-1435
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    • 1996
  • This paper obtains maximum allowable delay bounds for stability of network-based control systems and presents a network scheduling method which makes the network-induced delay be less than the maximum allowable delay bound. The maximum allowable delay bounds are obtained using the Lyapunov theorem. Using the network scheduling method, the bandwidth of a network can be allocated to each node and the sampling period of each sensor and controller can be determined. The presented method can handle three kinds of data (periodic, real-time asynchronous, and non real-time asynchronous data) and guarantee real-time transmissions of real-time synchronous data and periodic data, and possible transmissions of non real-time asynchronous data. The proposed method is shown to be useful by examples in two types of network protocols such as the token control and the central control.

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A Flexible Precise 2D-Image Reconstruction in X-Ray Computed Tomography for Soft Tissues Based On Non-Uniform Sampling Theorem

  • Kim, io-Sasaki;Hirokazu Okaniwa
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.80.4-80
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    • 2002
  • Performance of the previously proposed 2D-image reconstruction method for soft tissues in x-ray computed tomography is evaluated thoroughly through numerical experiments with 4 assumed absorption rates of different symmetries under practical conditions, and the following special features are made clear: It is quite precise, especially at points where the object taking larger values; about two orders less magnitude errors than the conventional most precise method when no noise existing, without any 1D- or 2D-interpolation. In spite of its high sensitivity to the noises, it is even more precise by about 8dB than the latter, to relative pojection data noise power of 5%.

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Design and Analysis of Reinforced Concrete Hyperbolic Cooling (철근콘크리트 쌍곡냉각탑의 설계 및 해석)

  • 장현옥;민창식
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.501-506
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    • 2000
  • An iterative numerical computational algorithm is presented to design a plate or shell element subjected to membrane and flexural forces. Based on equilibrium consideration, equations for capacities of top and bottom reinforcements in two orthogonal directions have been derived. The amount of reinforcement is determined locally, i.e., for each sampling point, from the equilibrium between applied and internal forces. Based on nonlinear analyses performed in a hyperbolic cooling tower, the analytically calculated ultimate load exceeded the design ultimate load from 50% to 55% for an analysis with relatively low to high tension stiffening, cases $\gamma$=10 and 15. For these cases, the design method gives a lower bound on the ultimate load with respect to Lower bound theorem, This shows the adequacy of th current practice at least for this cooling tower shell case studied. To generalize the conclusion more designs - analyses should be reformed with different shell configurations.

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Diffraction Anomalies on the Periodic Strip Grating over a Grounded Dielectric Layer in Case of Oblique Incidence and Arbitrary Polarization (임의의 편파로서 비스듬한 각도로 입사하는 전자파의 경우에 대한 접지된 유전체층 위에 놓여있는 주기적인 스트립격자 구조에서의 특이한 회절현상)

  • 조웅희;고지환;조영기
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.2
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    • pp.238-252
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    • 1998
  • Diffraction anomalies in the periodic strip grating over a grounded dielectric layer are investigated for the plane wave incidence case of both arbitrary(oblique) incidence angle and arbitrary polarization by use of the spectral domain method combined with the sampling theorem. Some numerical results for the Bragg and Off-Bragg blazing phenomena for the cases of arbitrary incidence angle and polarization as well as TE and TM polarization are presented along with discussions on those phenomena.

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Teaching of the Meaning of Proof Using Historic-genetic Approach - based on Pythagorean Theorem - (역사.발생적 전개를 따른 증명의 의미 지도 - 피타고라스 정리를 중심으로 -)

  • Song, Yeong-Moo;Lee, Bo-Bae
    • School Mathematics
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    • v.10 no.4
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    • pp.625-648
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    • 2008
  • We collected the data through the following process. 36 third-grade middle school students are selected, and we conducted ex-ante interviews for researching how they understand the nature of proof. Based on the results of survey, then we chose two students we took a lesson with the Branford's among the 36 samples. After sampling, historic-genetic geometry education, inspected carefully whether the Branford's method helps the students.

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Improved Iterative Method for Wavefront Reconstruction from Derivatives in Grid Geometry

  • Nguyen, Vu-Hai-Linh;Rhee, Hyug-Gyo;Ghim, Young-Sik
    • Current Optics and Photonics
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    • v.6 no.1
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    • pp.1-9
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    • 2022
  • This paper proposes a robust, simple zonal wavefront-estimation method in a grid sampling model. More slopes are added to the integral equation of the algorithm to improve the accuracy and convergence rate of this approach, especially for higher-order optical aberrations. The Taylor theorem is applied to clarify the mathematical description of the remaining error in the proposed method. Several numerical simulations are conducted to ensure the performance and improvement in comparison to the Southwell and previous algorithm. An experiment is also conducted according to deflectometry output and the results are verified using a reference measured with a stylus system.

On the Bayes risk of a sequential design for estimating a mean difference

  • Sangbeak Ye;Kamel Rekab
    • Communications for Statistical Applications and Methods
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    • v.31 no.4
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    • pp.427-440
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    • 2024
  • The problem addressed is that of sequentially estimating the difference between the means of two populations with respect to the squared error loss, where each population distribution is a member of the one-parameter exponential family. A Bayesian approach is adopted in which the population means are estimated by the posterior means at each stage of the sampling process and the prior distributions are not specified but have twice continuously differentiable density functions. The main result determines an asymptotic second-order lower bound, as t → ∞, for the Bayes risk of a sequential procedure that takes M observations from the first population and t - M from the second population, where M is determined according to a sequential design, and t denotes the total number of observations sampled from both populations.

A Long-term Durability Prediction for RC Structures Exposed to Carbonation Using Probabilistic Approach (확률론적 기법을 이용한 탄산화 RC 구조물의 내구성 예측)

  • Jung, Hyun-Jun;Kim, Gyu-Seon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.5
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    • pp.119-127
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    • 2010
  • This paper provides a new approach for durability prediction of reinforced concrete structures exposed to carbonation. In this method, the prediction can be updated successively by a Bayes' theorem when additional data are available. The stochastic properties of model parameters are explicitly taken into account in the model. To simplify the procedure of the model, the probability of the durability limit is determined based on the samples obtained from the Latin Hypercube Sampling(LHS) technique. The new method may be very useful in design of important concrete structures and help to predict the remaining service life of existing concrete structures which have been monitored. For using the new method, in which the prior distribution is developed to represent the uncertainties of the carbonation velocity using data of concrete structures(3700 specimens) in Korea and the likelihood function is used to monitor in-situ data. The posterior distribution is obtained by combining a prior distribution and a likelihood function. Efficiency of the LHS technique for simulation was confirmed through a comparison between the LHS and the Monte Calro Simulation(MCS) technique.

Simulation of Dynamic EADs Jamming Performance against Tracking Radar in Presence of Airborne Platform

  • Rim, Jae-Won;Jung, Ki-Hwan;Koh, Il-Suek;Baek, Chung;Lee, Seungsoo;Choi, Seung-Ho
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.3
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    • pp.475-483
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    • 2015
  • We propose a numerical scheme to simulate the time-domain echo signals at tracking radar for a realistic scenario where an EAD (expendable active decoy) and an airborne target are both in dynamic states. On various scenarios where the target takes different maneuvers, the trajectories of the EAD ejected from the target are accurately calculated by solving 6-DOF (Degree-of-Freedom) equations of the motion for the EAD. At each sampling time of the echo signal, the locations of the EAD and the target are assumed to be fixed. Thus, the echo power from the EAD can be simply calculated by using the Friis transmission formula. The returned power from the target can be computed based on the pre-calculated scattering matrix of the target. In this paper, an IPO (iterative physical optics) method is used to construct the scattering matrix database of the target. The sinc function-interpolation formulation (sampling theorem) is applied to compute the scattering at any incidence angle from the database. A simulator is developed based on the proposed scheme to estimate the echo signals, which can consider the movement of the airborne target and EAD, also the scattering of the target and the RF specifications of the EAD. For applications, we consider the detection probability of the target in the presence of the EAD based on Monte Carlo simulation.