• 제목/요약/키워드: Periodicity

검색결과 468건 처리시간 0.022초

EXISTENCE AND STABILITY OF ALMOST PERIODIC SOLUTIONS FOR A CLASS OF GENERALIZED HOPFIELD NEURAL NETWORKS WITH TIME-VARYING NEUTRAL DELAYS

  • Yang, Wengui
    • Journal of applied mathematics & informatics
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    • 제30권5_6호
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    • pp.1051-1065
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    • 2012
  • In this paper, the global stability and almost periodicity are investigated for generalized Hopfield neural networks with time-varying neutral delays. Some sufficient conditions are obtained for the existence and globally exponential stability of almost periodic solution by employing fixed point theorem and differential inequality techniques. The results of this paper are new and complement previously known results. Finally, an example is given to demonstrate the effectiveness of our results.

후두 스트로보스코피 (Laryngeal Stroboscopy)

  • 박영학;최지영
    • 대한후두음성언어의학회지
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    • 제19권2호
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    • pp.96-100
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    • 2008
  • Laryngeal stroboscopy is a important clinical tool in the diagnosis and evaluation of patients with voice disorders. Stroboscopic parameters evaluated during examination include symmetry, periodicity, glottic losure, amplitude, mucosal wave, and amplitude. Stroboscopy can provide useful information on glottal closure patterns in patient with/without vocal fold pathology and this paper describes the stroboscopic findings of the laryngeal pathologic lesions.

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THE STUDY OF THE DIFFERENCE BETWEEN GALLOPING CABLE AND SUSPENSION BRIDGE CABLE

  • Oh, Hye-Young
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제4권1호
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    • pp.35-46
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    • 1997
  • We consider the common and different results between the oscillation of galloping cable and the oscillation of suspension bridge cable through the long-term behavior. Numerical results are presented by using the second-order Runge-Kutta method under various initial conditions. There appeared to be nonlinear forms. Periodicity, symmetry, and longitudinality are differently appeared in two kinds of cables.

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김포국제공항 지역의 시정변화에 대한 통계적 분석 (The Statistical Analysis to predict Visibility Changes in KIMPO International Airport Area)

  • 송병흠;최승희
    • 한국항공운항학회지
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    • 제7권1호
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    • pp.91-99
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    • 1999
  • On the basis of KTMPO visibility data measured for 17 years(Jan.1983 to Oct.1999), time-series data analysis is accomplished for regression trend, cyclical periodicity, dependency of these data in this paper. After that, to predict visibility in KIMPO international airport a probability model is presented using this statistic probability characteristics.

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무요소법을 이8한 결정고체의 에너지 띠 구조 계산 (Energy band structure calculation of crystalline solids using meshfree methods)

  • 전석기;임세영
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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    • pp.623-628
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    • 2002
  • A meshfree formulation for the calculation of energy band structure is presented. The conventional meshfree shape function is modified to handle the periodicity of Bravais lattice, and applied to the calculation of real-space electronic-band structure. Numerical examples include the Kronig-Penney model potential and the empirical pseudopotentials of diamond and zinc-blonde semiconductors. Results demonstrate that the meshfree method be a promising one as a real-space technique for the calculations of diverse physical band structures.

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수질 자료에 대한 ARIMA 모형 적용(지역환경 \circled2) (ARIMA Modeling for Monthly Oxygen Demand Data)

  • 허용구;박승우
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2000년도 학술발표회 발표논문집
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    • pp.590-598
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    • 2000
  • A multiplicative ARIMA model was tested and applied to analyze the periodicity and trends of 168 monthly oxygen demand data from the Noryanggin water quality gauging station in the downstream Han River. ARIMA model was identified to fit to the data using ACF and PACF tests, and the parameters estimated using an unconditional least square method. The residuals between the observed and forecasted data were acceptable with the Porte-Manteau test. A forecast of DO changes was made for its applications.

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Radiation From a Current Filament Located inside a Cylindrical Frequency Selective Surface

  • Uzer, Ali;Ege, Tuncay
    • ETRI Journal
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    • 제26권5호
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    • pp.481-485
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    • 2004
  • We consider electromagnetic field radiation properties of a current filament placed at the origin of a cylindrical frequency selective surface (CFSS). The CFSS consists of free standing metal strips with two-dimensional periodicity. The analysis is based on a cylindrical Floquet mode wave expansion technique. We observed that near the half wavelength resonance frequencies, there exist some specific frequencies at which the surface becomes totally transparent.

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주기적인 강성분포를 갖는 구형쉘의 좌굴해석 (Buckling Analysis of Spherical Shells With Periodic Stiffness Distribution)

  • 정환목
    • 한국공간구조학회논문집
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    • 제4권4호
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    • pp.77-84
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    • 2004
  • Researches on spherical shell which is most usually applied have been completed by many investigators already and generalized numerical formula was derived. But the existent researches are limited to those on spherical shell with isotropic or orthotropic roof stiffness, periodic distribution of roof stiffness that can be caused by spherical and latticed roof system is not considered. Therefore, the object of this study is to develop a structural analysis program to analyze spherical shells that have periodicity of roof stiffness distribution caused by latticed roof of large space structure, grasp buckling characteristics and behavior of structure.

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Preparation and Properties of New Metal-chain Compounds with Commensurate Peierls Structure

  • Lee, Kuk-Haeng;Kim, Ja-Hong;Mizuno, Masagi
    • Bulletin of the Korean Chemical Society
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    • 제8권3호
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    • pp.137-140
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    • 1987
  • New platinum chain compounds, $[M(en)_2]_{0.80}[Pt(ox)_2]{\cdot}2H_2O$ where M = Cu or Pt, en = ethylenediamine and ox = oxalate, have been prepared and found to have a commensurate Peierls structure as evidenced by the five-fold Pt chain periodicity and unusually low electrical conductivity $(1.5{\times}10^{-5}{\sim}5.7{\times}10^{-3}S/cm)$. Including two other compounds with the Peierls structure, their characteristic features were deduced and explained from the point of view of the band theory.

Periodicity in Chemical Shifts and Temperature Coefficients of $\alpha$-helix in TFE Solution

  • Suh, Jeong-Yong;Choi, Byong-Seok
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1997년도 학술발표회
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    • pp.42-42
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    • 1997
  • Local conformation of helical peptides in TFE solution are studied by NMR spectroscopy. One is a helix containing proline and the other is its alanine derivative in which alanine is substituted for the proline. Chemical shift and temperature coefficient In NMR spectroscopy can be used preliminarily to determine secondary structure in proteins and peptides.(omitted)

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