• 대한수학회보
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• 제47권5호
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• pp.889-905
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• 2010

In this paper, a distribution free approach to the parameter estimation of a simple bilinear model with periodic coefficients is presented. The proposed method relies on minimum distance estimator based on the autocovariances of the squared process. Consistency and asymptotic normality of the estimator, as well as hypotheses testing, are derived. Numerical experiments on simulated data sets are presented to highlight the theoretical results.

• 대한전기학회논문지
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• 제31권7호
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• pp.18-24
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• 1982

We derived an optimal control of the Stochastic Bilinear Systems. For that we, firstly, formulated stochastic bilinear system and estimated its state when the system state is not directly observable. Optimal control problem of this system is reviewed on the line of three optimization techniques. An optimal control is derived using Hamilton-Jacobi-Bellman equation via dynamic programming method. It consists of combination of linear and quadratic form in the state. This negative feedback control, also, makes the system stable as far as value function is chosen to be a Lyapunov function. Several other properties of this control are discussed.

• 한국통신학회논문지
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• 제11권5호
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• pp.315-322
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• 1986

本 論文은 　圓函數를 利用한 IIR digital 필터 設計에 關하여 硏究한 것이다. Digital 　圓函數는 analog 　圓函數로부터 Bilinear z 變換에 依하여 求하였다. Bilinear z 變換된 函數로 digital필터를 設計하면 aliasing 現象은 避할 수 있으나 周波數歪曲이 發生한다. Analog函數를 digital函數로 變換하면 이러한 影響으로 遮斷周波數 領域이 不一致하므로 이것을 避하기 爲하여 prewarping法을 利用하였다. 마지막으로, 컴퓨터 simulation에 依하여 analog 크기 特性과 digital 크기 特性을 比較한 結果, prewarping을 한 digital 크기特性이 analog 크기 特性에 比하여 改善되었음을 確認할 수 있었다.

• Earthquakes and Structures
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• 제8권5호
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• pp.1055-1067
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• 2015

A theoretical procedure to estimate spectral displacement of a hysteretic oscillator with bilinear stiffness excited by band-limited excitation is presented. The stochastic method of ground-motion simulation is combined with the random vibration theory to compute linear and nonlinear structural response. The response is obtained by computing the root-mean-square oscillator response using dissipation energy balancing by integrating over all energy levels of system weighting with the stationary probability density of the energy. The results are presented in a convenient form, and the accuracy of the procedure is assessed by comparison with results obtained with the time-domain method using the recorded data. The model shows little or no bias at the structural period of engineering interest.

• 한국정보통신학회논문지
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• 제16권10호
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• pp.2108-2112
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• 2012

본 논문에서는 정변형을 이용하여 파노라마 영상으로 변환하고 파노라마 영상으로 변환하는 과정에서 손실되는 영상 정보를 복원하기 위하여 양선형 보간법을 적용하여 개선된 파노라마 영상을 획득할 수 있는 방법을 제안한다. 본 논문에서 제안한 어안 렌즈 영상 재구성 방법의 성능을 평가하기 위하여 다양한 어안 렌즈 영상을 대상으로 실험한 결과, 기존의 방법보다 영상을 재구성하는데 효과적인 것을 확인하였다.

• 대한전기학회논문지
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• 제39권6호
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• pp.598-606
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• 1990

Common problems encountered when orthogonal functions are used in system analysis and state estimation are the time consuming process of high order matrix inversion required in finding the Kronecker products and the truncation errors. In this paper, therefore, a method for the analysis of bilinear systems using Walsh, Block pulse, and Haar functions is devised, Then, state estimation of bilinear system is also studied based on single term expansion of orthogonal functions. From the method presented here, when compared to the other conventional methods, we can obtain the results with simpler computation as the number of interval increases, and the results approach the original function faster even at randomly chosen points regardless of the definition of intervals. In addition, this method requires neither the inversion of large matrices on obtaining the expansion coefficients nor the cumbersome procedures in finding Kronecker products. Thus, both the computing time and required memory size can be significantly reduced.

• 제어로봇시스템학회논문지
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• 제19권9호
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• pp.827-833
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• 2013

In this paper, an efficient computational method is presented for state space analysis of bilinear systems via Legendre wavelets. The differential matrix equation is converted to a generalized Sylvester matrix equation by using Legendre wavelets as a basis. First, an explicit expression for the inverse of the integral operational matrix of the Legendre wavelets is presented. Then using it, we propose a preorder traversal algorithm to solve the generalized Sylvester matrix equation, which greatly reduces the computation time. Finally the efficiency of the proposed method is discussed using numerical examples.

• 소음진동
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• 제7권1호
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• pp.135-142
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• 1997

This paper presents a digital modeling technique of the distributed system. The basic idea of the proposed technique is to discretize a continuous system with respect to the spatial coordinates using bilinear method. The response of the discretized system is analyzed by Laplace transform and z-transform. The computational results in torsional shaft and Timoshenko beam using the proposed technique are compared with the exact solutions and the results of finite element method.

• 대한전자공학회논문지
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• 제25권12호
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• pp.1594-1600
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• 1988

In this paper, an effective method in analyzing a class of bilinear systems via Taylor polynomials is proposed. The result derived by Yang and Chen shows an implicit form for unknown state vector and requires to solve a linear algebraic equation with large dimension when the number of terms used increase. In comparison to the result of Yang and Chen, the method in this paper gives a closed form for unknown state vector and does not need to solve any linear algebraic equation.

• 충청수학회지
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• 제21권3호
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• pp.403-411
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• 2008

In 2005, A. Saxena, B. Soh and S. Priymak [10] proposed a two-flow blind identification protocol. But it has a weakness of the active-intruder attack and uses the pairing operation that causes slow implementation in smart cards. In 2008, Y. W. Lee [9] made a method of the active-intruder attack on their identification scheme and proposed a new zero-knowledge blind identification protocol for smart cards. In this paper, we give more simple and fast protocols than above protocols such that the prover using computationally limited devices such as smart cards has no need of computing the bilinear pairings. Computing the bilinear pairings is needed only for the verifier and is secure assuming the hardness of the Discrete-Logarithm Problem (DLP).