• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.9
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• pp.431-438
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• 2001

This paper present experimental results of source identification for non-minimum phase system. Generally, a causal linear system may be described by matrix form. The inverse problem is considered as a matrix inversion. Direct inverse method can\`t be applied for a non-minimum phase system, the reason is that the system has ill-conditioning. Therefore, in this study to execute an effective inversion, SVD inverse technique is introduced. In a Non-minimum phase system, its system matrix may be singular or near-singular and has one more very small singular values. These very small singular values have information about a phase of the system and ill-conditioning. Using this property we could solve the ill-conditioned problem of the system and then verified it for the practical system(cantilever beam). The experimental results show that SVD inverse technique works well for non-minimum phase system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.2
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• pp.357-364
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• 1996

This paper presents a new blind identification method of nonminimum phase FIR systems without employing higher-order statistics. It is based on the observation that the absolute mean of a second-order white sequence can measure the higher-order whiteness of the sequence. The proposed method may be a new alternative way to the higher-order statistics approaches. Some computer simulations show that the absolute mean is exactly estimated and the proposed method can overcome the disadvantages of the higher-order statistics approaches.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.6
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• pp.89-96
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• 1985

A pole-placement control of discrete, deterministic, single-input single-output nonmini-mum phase systems is considered using a model reference type approach. The proposed pole-placement controller is designed in the parameter form to make the transfer function of the controller equal to that of the reference model with only single variable polynomial S(q-1). The proposed adaptive pole-placement controllr is designed with the true system para-meters by applying the adaptation method to the proposed pole-placement controller.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.8
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• pp.32-42
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• 2022

Asymptotic tracking of a non-minimum phase nonlinear system has been a popular topic in control theory and application. In this paper, we propose a new control scheme to achieve asymptotic output tracking in anon-minimum phase nonlinear system for periodic trajectories through an iterative learning control with the stable inversion. The proposed design method is robust to parameter uncertainties and periodic external disturbances since it is based on iterative learning. The performance of the proposed algorithm was demonstrated through the simulation results using a typical non-minimum nonlinear system of an inverted pendulum on a cart.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6702-6709
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• 2014

In this study, a susceptibility weighted image (SWI) showed a wrapped phase and a non-uniformity of the rapid susceptibility difference. Consequently, the bandwidth limits at low frequency were improved by applying HPF. From November 2013 to March 2014, a three-dimensional SWI was obtained from patients and compared with the existing images and HPF phase images. The maximum and minimum signal intensity differences and non-uniformity were analyzed. As a result, a high pass filter before and after applying the maximum and minimum of the signal intensity difference was decreased by 274.16% (498.98), and the non-uniformity was decreased by 439.55% (19.83). After applying the HPF, a comparison with the existing phase images revealed the HPF phase images to have high signal and image uniformity of the SWI image. A high pass filter method can effectively remove the non-uniformity and improve the overall image quality.

• Journal of KIISE
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• v.43 no.7
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• pp.812-819
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• 2016

This paper introduces and analyzes the theoretical basis and method of the conventional initial-value assignment problem and feasibility of image segmentation. The paper presents topological evidence and a method of appropriate initial-value assignment based on topology theory. Subsequently, the paper shows minimum conditions for feasibility of image segmentation based on separation axiom theory of topology and a validation method of effectiveness for image modeling. As a summary, this paper shows image segmentation with its mathematical validity based on topological analysis rather than statistical analysis. Finally, the paper applies the theory and methods to conventional Gaussian random field model and examines effectiveness of GRF modeling.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.23-30
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• 2022

The active phased array antenna system performs beam steering, multi-beam formation and adaptive beam forming by controlling the amplitude and phase of signals fed to each radiating element. In order to obtain the desired radiation characteristics using an active phased array antenna system, the accurate amplitude and phase of the signal must be fed to each radiating element; however, due to various causes, the signal errors occurs in each radiating element. In this paper, a signal error estimation method of each radiating element is proposed. The proposed method simplifies the process of signal error estimation, and can quickly and accurately calculate the signal error.

• Proceedings of the KIEE Conference
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• 1986.07a
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• pp.212-214
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• 1986

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.699-702
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• 2012

본 논문에서는 WCDMA(Wide Code Division Multiple Access) 시스템 사양을 만족시키는 주파수 합성기 블록 중 위상잡음 및 전력소모의 최적 설계가 필요한 LC-VCO(voltage controlled oscillator)의 설계를 제안 하였다. 최적 설계를 위한 핵심내용은 LC-tank의 손실성분을 보상하는 MOS트랜지스터의 전달컨덕턴스와 인덕턴스 평면에 여유이득라인과 튜닝 범위 라인을 그어 설계 가능한 영역 내에서 위상잡음이 최소가 되는 인덕턴스 값을 구하고 선택하는 것이다. 제안한 최적 설계방법에 의해 진행된 LC-VCO의 시뮬레이션 결과 위상잡음 특성은 1MHz옵셋에서 -113dBc/Hz였다.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.95-97
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• 2000

배열 안테나에서 안테나 소자의 개수의 증가는 안테나의 이득을 증가시킬 수 있으므로 열악한 채널 환경에서도 채널이 필요로 하는 링크 마진을 얻을 수 있다. 그러나, 기존 빔 형성기에서 사용되는 배열 안테나 기법은 많은 계산량과 소모 메모리량 때문에 배열 소자의 개수에 제한이 따르게 된다. 이러한 문제를 해결하기 위하여 본 논문에서는 배열 안테나의 구조에 따른 위상차이를 보상하여 적은 계산량과 메모리를 갖는 배열 위상 차이 보상을 이용한 평행 구조 빔 형성기를 제안한다 배열 위상 차이를 보상하는 기법으로 적은 계산량과 메모리로 개수가 많은 긴 배열 안테나에서 얻을 수 있는 분해능과 안테나 이득을 얻을 수 있다. 제안된 기법의 성능을 비교하기 위해 기존의 빔 형성기법으로delay-sum 빔 형성기와 공분산 행렬의 고유치 해석을 통한 고유벡터 기법의 빔 스펙트럼과 연산량을 비교하였다. 제안된 기법으로 빔 형성을 하면, 배열 안테나의 소자의 개수가 늘어나도 기존의 방법보다 최소 30%의 연산량으로 스펙트럼 상 비슷한 성능을 얻을 수 있다.