• 제목/요약/키워드: Autocorrelation Function

검색결과 249건 처리시간 0.029초

Evaluation of randomness of binary random sequence

  • Harada, Hiroshi;Kashiwagi, Hiroshi;Takada, Tadashi
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.979-983
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    • 1989
  • This paper proposes a new concept, called merit factor Fr, for evaluating the randomness of binary random sequences. The merit factor Fr is obtained from the expected values of the autocorrelation function of the binary random sequence. Using this merit factor Fr, randomness of the binary random sequences generated by the random sampling method is evaluated.

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Quantum Mechanical Effects on Dynamical Behavior of Simple Liquids

  • Kim, Tae-Jun;Kim, Hyo-Joon
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2233-2236
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    • 2011
  • We evaluate quantum-mechanical velocity autocorrelation functions from classical molecular dynamics simulations using quantum correction approaches. We apply recently developed approaches to supercritical argon and liquid neon. The results show that the methods provide a solution more efficient than previous methods to investigate quantum-mechanical dynamic behavior in condensed phases. Our numerical results are found to be in excellent agreement with the previous quantum-mechanical results.

임의의 잡음분포에 있어서 신호검출의 최적 파라미터 결정

  • 최무영;진용옥
    • 한국통신학회:학술대회논문집
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    • 한국통신학회 1983년도 추계학술발표회논문집
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    • pp.102-104
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    • 1983
  • 본 논문은 광대역에서 임의로 발생하는 TONE BURST 파형의 패턴을 여러파라미터로 분석하여 이를 잡음과 섞여있는 경우에 적용하였다. 그결과 특정의 REFERENCE 신호가 없는 경우에는 AUTOCORRELATION 향수가 TONEBURST파형분석에 최적 파라미터 임을 입증한다.

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ARMAX 모델의 매개변수 추정을 위한 최적 입력 신호의 설계 (Design of the Optimal Input Singals for Parameter Estimation in the ARMAX Model)

  • 이석원;양흥석
    • 대한전기학회논문지
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    • 제37권3호
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    • pp.180-185
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    • 1988
  • This paper considers the problem of the optimal input design for parameter estimtion in the ARMAX model in which the system and noise transfer function have the common denominator polynomial. Deriving the information matrix, in detail, for the assumed model structure and using the autocorrelation functin of the filtered input as design variables, it is shown that D-optimal input signal can be realized as an autoregressive moving average process. Computer simulations are carried out to show the standard-deviation reduction in the parameter estimtes using the optimal input signal.

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점성감쇠기가 설치된 건물의 내풍해석 (Wind-induced Vibration of Building Structures with Viscoelastic Dampers)

  • 주석준;민경원;홍성목
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1995년도 봄 학술발표회 논문집
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    • pp.130-135
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    • 1995
  • Wind-induced vibration of buildings with viscoelastic dampers are studied analytically. The added viscoelastic dampers change the damping distribution and reduce the response of buildings. The distribution of damping resistance that results from these viscoelastic dampers is known as non-classical or non-proportional. Non-classically damped structures are analyzed by state-space approach. However, this approach is complex and time-consumming compared to classical approach. This paper is aimed at the analysis of wind-induced Vibration Of buildings With Viscoelastic dampers. The Process Of State-Space approach is studied and the approximate analysis is suggested to overcome the complex and time-consuming access. For numerical certification, PSDF(Power Spectral Density Function) is obtained. Autocorrelation function is obtained in time domain and PSDF is obtained by fourier transformation of this function in frequency domain. It is found that Approximate method can give close approximation to exact solution.

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창원시 대산면 강변충적층의 지하수위, 하천수위, 강수량의 관련성 연구

  • 정재열;함세영;김형수;차용훈;장성
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.447-450
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    • 2004
  • This study was conducted to characterize groundwater and river-water fluctuations at a riverbank filtration site in Daesan-myeon adjacent to the Nakdong River, using time series analysis. Water levels from six observation wells from January 2003 to October 2003 were measured. The autocorrelation analysis indicates that the wells are divided into three groups: group 1 represents strong linearity and memory, group 2 intermediate linearity and memory, and group 3 weak linearity and memory. The analysis indicates that groundwater levels in different monitoring wells vary in response to river-water levels, groundwater withdrawal and seasonal rainfall. Cross-correlation was also divided into three groups. Group 1 shows the highest cross-correlation function (0.49 - 0.54) for a lag time of 0 hours, group 2 intermediate cross-correlation function (0.34 - 0.45), and group 3 the lowest cross-correlation function (0.23 - 0.25). Different cross-correlation functions among the 3 groups are interpreted as an effect of tile distance from the river to the pumping wells.

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Molecular Dynamic Study of a Polymeric Solution (I). Chain-Length Effect

  • Lee Young Seek;Ree Taikyue
    • Bulletin of the Korean Chemical Society
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    • 제3권2호
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    • pp.44-49
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    • 1982
  • Dynamic and equilibrium structures of a polymer chain immersed in solvent molecules have been investigated by a molecular dynamic method. The calculation employs the Lennard-Jones potential function to represent the interactions between two solvent molecules (SS) and between a constituent particle (monomer unit) of the polymer chain and a solvent molecule (CS) as well as between two non-nearest neighbor constituent particles of the polymer chain (CC), while the chemical bond for nearest neighbor constituent particles was chosen to follow a harmonic oscillator potential law. The correlation function for the SS, CS and CC pairs, the end-to-end distance square and the radius of gyration square were calculated by varying the chain length (= 5, 10, 15, 20). The computed end-to-end distance square and the radius of gyration square were found to be in a fairly good agreement with the corresponding results from the random-flight model. Unlike earlier works, the present simulation rsesult shows that the autocorrelation function of radius of gyration square decays slower than that of the end-to-end distance square.

창원시 대산면 강변여과수의 수질과 낙동강 수질의 관련성 연구

  • 장성;함세영;김형수;차용훈;정재열
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.451-454
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    • 2004
  • The study aims to assess the quality of bank filtrate in relation to streamflow and physico-chemical properties of the stream. Turbidity, pH, temperature and dissolved oxygen (DO) of Nakdong River and riverbank filtrate were statistically analyzed. The physico-chemical properties of riverbank filtrate were measured from irregularly different seven pumping wells every day. Autocorrelation analyses were conducted to the qualities of stream water and bank filtrated water. Temperature, pH and DO of streamflow shows strong linearity and long memory effect, indicating the effect of seasonal air temperature and rainy season. Temperature of riverbank filtrate shows weak linearity and weak memory, indicating differently from the trend of stream temperature. Turbidity of steramflow shows strong linearity and long memory effect, while turbidity of riverbank filtrate indicates weak linearity and weak memory. Cross-correlation analysis shows low relation between turbidity, pH, temperature and DO of riverbank filtrate and those of streamflow. Turbidity of streamflow was largely affected by the streamflow rate, showing a similar trend with autocorrelation function of streamflow rate. The turbidity of riverbank filtrate has a lag time of 25 hours. This indicates that turbidity of streamflow in a dry season has very low effect on the turbidity of riverbank filtrate, and a high turbidity of the stream in a rainy season has a fairly low effect on the turbidity of riverbank filtrate.

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다중 오디오 특징을 이용한 유해 동영상의 판별 (Classification of Phornographic Video with using the Features of Multiple Audio)

  • 김정수;정명범;성보경;권진만;구광효;고일주
    • 한국HCI학회:학술대회논문집
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    • 한국HCI학회 2009년도 학술대회
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    • pp.522-525
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    • 2009
  • 본 논문에서는 인터넷의 역기능으로 현대 사회에 큰 문제를 야기 시키는 음란성 유해 동영상을 내용기반으로 판별하기 위한 방법을 제안하였다. 유해 동영상에서 오디오 데이터를 이용하여 특징을 추출하였다. 사용된 오디오 특징은 주파수 스펙트럼, 자기상관, MFCC이다. 음란성의 내용이 될 수 있는 소리의 특징을 추출하였고 동영상 전체 오디오에서 해당 소리의 특징과 일치하는지를 측정하여 유해성을 판별하였다. 제안한 방법의 실험은 각 특징마다 유해 판별 측정 결과와 다중 특징을 이용한 측정 결과를 비교 수행하였다. 하나의 오디오 특징만을 추출하여 사용하였을 때 보다 다중 특징의 사용이 좋은 결과를 얻을 수 있었다.

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다항식 $z^{d}+(z+1)^{d}$에 의해 발생된 이상적인 자기상관을 갖는 주기 $2^{m}-1$의 이진 의사불규칙 시퀀스 (Binary pseudorandom sequences of period $2^{m}-1$ with ideal autocorrelation generated by the polynomial $z^{d}+(z+1)^{d}$)

  • 노종선;정하봉;윤민선
    • 한국통신학회논문지
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    • 제23권5호
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    • pp.1165-1172
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    • 1998
  • 본 논문에서는 다항식 $z^{d}+(z+1)^{d}$를 이용하여 이상적인 자기상관특성을 갖는 주기 $2^{m}-1$의 이진 의사불규칙시퀀스를 구성하는 것을 보였다. 다항식으로부터 얻어진 시퀀스는 어떤 d값에서는 m-시퀀스가된다. 또한 k가 양의 정수이고 m이 $3k{\pm}1$일 때 이상적인 자기상관특성을 갖는 새로운 이진 시퀀스를 산출하는 몇몇의 d값을 발견했다. 이들 새로운 시퀀스는 trace함수를 이용하여 표현하였으며 그 결과들을 표로 나타내었다.

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