• 제목/요약/키워드: Discrete System

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뇌파 및 자율신경계 반응특성에 의한 기본정서의 구분 (DIFFERENTIATION OF BASIC EMOTIONS BY EEG AND AUTONOMIC RESPONSES)

  • 이경화;이임갑;손진훈
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 1999년도 춘계학술발표논문집 논문집
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    • pp.11-15
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    • 1999
  • The discrete state theory on emotion postulated that there existed discrete emotions, such as happiness, anger, fear, disgust, and so forth. Many investigators who emphasized discreteness of emotions have suggested that discrete emotions entailed their specific activities in the autonomic nervous system. The purposes of this study were to develop a model of emotion-specific physiological response patterns. The study postulated six emotions (i.e., happiness, sadness, anger, disgust, fear, and surprise) as the basic discrete emotions. Thirty eight college students participated in the present study. Twelve slides (2 for each emotion category) were presented to the subjects in random order. During resting period of 30 s prior to the presentation of each slide, four presentation of each slide, four physiological measures (EEG, ECG, EDA, and respiration) were recorded to establish a baseline. The same physiological measures were recorded while each slide was being presented for 60 s (producing an emotional sate). Then, the subjects were asked to rate the degree of emotion induced by the slide on semantic differential scales. This procedure was repeated for every slide. Based upon the results, a model of emotion-specific physiological response patterns was developed: four emotion (fear, disgust, sadness, and anger) were classified according to the characteristics of EEG and autonomic responses. However, emotions of happiness and surprise were not distinguished by any combination of the physiological measures employed in this study, suggesting another appropriate measure should be adopted for differentiation.

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이산 Convolution 적산의 z변환의 증명을 위한 인과성의 필요에 대한 재고 (A Reconsideration of the Causality Requirement in Proving the z-Transform of a Discrete Convolution Sum)

  • 정태상;이재석
    • 대한전기학회논문지:시스템및제어부문D
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    • 제52권1호
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    • pp.51-54
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    • 2003
  • The z-transform method is a basic mathematical tool in analyzing and designing digital signal processing systems for discrete input and output signals. There are may cases where the output signal is in the form of a discrete convolution sum of an input function and a designed digital processing algorithm function. It is well known that the z-transform of the convolution sum becomes the product of the two z-transforms of the input function and the digital processing function, whose proofs require the causality of the digital signal processing function in the almost all the available references. However, not all of the convolution sum functions are based on the causality. Many digital signal processing systems such as image processing system may depend not on the time information but on the spatial information, which has nothing to do with causality requirement. Thus, the application of the causality-based z-transform theorem on the convolution sum cannot be used without difficulty in this case. This paper proves the z-transform theorem on the discrete convolution sum without causality requirement, and make it possible for the theorem to be used in analysis and desing for any cases.

A Discrete State-Space Control Scheme for Dynamic Voltage Restorers

  • Lei, He;Lin, Xin-Chun;Xue, Ming-Yu;Kang, Yong
    • Journal of Power Electronics
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    • 제13권3호
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    • pp.400-408
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    • 2013
  • This paper presents a discrete state-space controller using state feedback control and feed-forward decoupling to provide a desirable control bandwidth and control stability for dynamic voltage restorers (DVR). The paper initially discusses three typical applications of a DVR. The load-side capacitor DVR topology is preferred because of its better filtering capability. The proposed DVR controller offers almost full controllability because of the multi-feedback of state variables, including one-beat delay feedback. Feed-forward decoupling is usually employed to prevent disturbances of the load current and source voltage. Directly obtaining the feed-forward paths of the load current and source voltage in the discrete domain is a complicated process. Fortunately, the full feed-forward decoupling strategy can be easily applied to the discrete state-space controller by means of continuous transformation. Simulation and experimental results from a digital signal processor-based system are included to support theoretical analysis.

Discrete Multi-Wavelet 변환을 이용한 LMS기반 적응 등화기 설계 (Design of LMS based adaptive equalizer using Discrete Multi-Wavelet Transform)

  • 최윤석;박형근
    • 한국정보통신학회논문지
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    • 제11권3호
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    • pp.600-607
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    • 2007
  • 차세대 이동 멀티미디어 통신에서는 전송지연을 줄이고 버스트 시변채널의 시간변화를 제한하기 위해 버스트 전송이 많이 사용된다. 그러나 채널적응을 위한 훈련 심볼은 짧은 길이의 버스트 데이터에 대해 심각한 문제를 야기할 수 있다. 따라서 심볼에 대한 적응 등화기의 설계에 있어서 짧은 길이의 훈련 심볼과 빠른 수렴을 갖는 적응 알고리즘이 필요로 된다. 본 논문에서는 DMWT (discrete multi-wavelet transform)과 LMS(least mean square) adaptation 을 갖는 적응 등화기를 제안한다. 제안된 등화기는 복잡성의 증가를 최소화하면서도 현재의 transform-domain equalizer보다 빠른 수렴을 갖는다.

Summarized IDA curves by the wavelet transform and bees optimization algorithm

  • Shahryari, Homayoon;Karami, M. Reza;Chiniforush, Alireza A.
    • Earthquakes and Structures
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    • 제16권2호
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    • pp.165-175
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    • 2019
  • Incremental dynamic analysis (IDA), as an accurate method to evaluate the parameters of structural performance levels, requires many non-linear time history analyses, using a set of ground motion records which are scaled to different intensity levels. Therefore, this method is very computationally demanding. In this study, a new method is presented to estimate the summarized (16%, 50%, and 84% fractiles) IDA curves of a first-mode dominated structure using discrete wavelet transform and bees optimization algorithm. This method reduces the number of required ground motion records for the prediction of the summarized IDA curves. At first, a subset of first list ground motion records is decomposed by means of discrete wavelet transform which have a low dispersion estimating the summarized IDA curves of equivalent SDOF system of the main structure. Then, the bees algorithm optimizes a series of factors for each level of detail coefficients in discrete wavelet transform. The applied factors change the frequency content of original ground motion records which the generated ground motions records can be utilized to reliably estimate the summarized IDA curves of the main structure. At the end, to evaluate the efficiency of the proposed method, the seismic behavior of a typical 3-story special steel moment frame, subjected to a set of twenty ground motion records is compared with this method.

이산화 체인 모델을 이용한 자전거 변속 과도상태 해석 (A Transient Analysis in Bicycle Shifting using A Discrete Chain Model)

  • 김정윤
    • 산업경영시스템학회지
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    • 제36권4호
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    • pp.25-30
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    • 2013
  • This article deals with the transient analysis in bicycle shifting using a discrete chain model. Among the various components of a bicycle, we focused in the power-transmissions on the contact points between the chain element and sprocket. And by imposing kinematic motions on the front and rear derailleurs, we analyzed the shifting mechanism for increasing the rotational speed of rear wheel. In order to build the dynamic analysis model, we first tore down the real bicycle and measured each component's design parameters. Then we made 3-dimensional CAD models for each component related to the power transmission of a bicycle. Using the converted 3-dimensional dynamic model for the simulation program, we performed non-shifting and shifting dynamic analysis. As a result, we investigated the dynamic behaviors of a discrete chain model focused on the interaction between the chain and sprocket wheel.

Robust $H_{\infty}$ Control for Uncertain Two-Dimensional Discrete Systems Described by the General Model via Output Feedback Controllers

  • Xu, Huiling;Zou, Yun;Xu, Shengyuan;Guo, Lei
    • International Journal of Control, Automation, and Systems
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    • 제6권5호
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    • pp.785-791
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    • 2008
  • This paper considers the problem of robust $H_{\infty}$ control for uncertain 2-D discrete systems in the General Model via output feedback controllers. The parameter uncertainty is assumed to be norm-bounded. The purpose is the design of output feedback controllers such that the closed-loop system is stable while satisfying a prescribed $H_{\infty}$ performance level. In terms of a linear matrix inequality, a sufficient condition for the solvability of the problem is obtained, and an explicit expression of desired output feedback controllers is given. An example is provided to demonstrate the application of the proposed method.

복수휴가형 이산시간 GI/G/1 대기체계에 대한 수정부가변수법 (On the Modified Supplementary Variable Technique for a Discrete-Time GI/G/1 Queue with Multiple Vacations)

  • 이두호
    • 대한산업공학회지
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    • 제42권5호
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    • pp.304-313
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    • 2016
  • This work suggests a new analysis approach for a discrete-time GI/G/1 queue with multiple vacations. The method used is called a modified supplementary variable technique and our result is an exact transform-free expression for the steady state queue length distribution. Utilizing this result, we propose a simple two-moment approximation for the queue length distribution. From this, approximations for the mean queue length and the probabilities of the number of customers in the system are also obtained. To evaluate the approximations, we conduct numerical experiments which show that our approximations are remarkably simple yet provide fairly good performance, especially for a Bernoulli arrival process.

Exact Algorithms of Transforming Continuous Solutions into Discrete Ones for Bit Loading Problems in Multicarrier Systems

  • Chung, Yong-Joo;Kim, Hu-Gon
    • Management Science and Financial Engineering
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    • 제16권3호
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    • pp.71-84
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    • 2010
  • In this study, we present the exact methods of transforming the continuous solutions into the discrete ones for two types of bit-loading problem, marginal adaptive (MA) and rate adaptive (RA) problem, in multicarrier communication systems. While the computational complexity of existing solution methods for discrete optimal solutions depends on the number of bits to be assigned (R), the proposed method determined by the number of subcarriers (N), making ours be more efficient in most cases where R is much larger than N. Furthermore our methods have some strength of their simpler form to make a practical use.

DISTURBANCE ATTENUATION FOR A CLASS OF DISCRETE-TIME SWITCHED SYSTEMS WITH EXPONENTIAL UNCERTAINTY

  • Li, Changlin;Long, Fei;Ren, Guohui
    • 대한수학회지
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    • 제48권4호
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    • pp.775-795
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    • 2011
  • The disturbance attenuation problem for a class of discretetime switched linear systems with exponential uncertainties via switched state feedback and switched dynamic output feedback is investigated, respectively. By using Taylor series approximation and convex polytope technique, exponentially uncertain discrete-time switched linear system is transformed into an equivalent switched polytopic model with additive norm bounded uncertainty. For such equivalent switched model, one designs its switching strategy and associated state feedback controllers and dynamic output feedback controllers so that whole switched model is asymptotical stabilization with H-in nity disturbance attenuation base on switched Lyapunov function and LMI approach. Finally, two numerical examples are presented to illustrate our results.