Chaotic Synchronization of Regular and Irregular Complex Networks with Fractional Order Oscillators

Cornelio Posadas-Castillo,Sara Angulo-Guzman,Miguel Angel Platas-Garza,David Alejandro Diaz-Romero,Didier Lopez-Mancilla 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.4

Synchronization of N-coupled fractional-order (FO) chaotic oscillators arranged in regular and irregulartopologies is numerically studied. Synchronization is achieved based on the coupling matrix from the complexsystems theory. In particular, we consider complex dynamical networks composed by Lorenz, Volta, Duffing andFinancial FO chaotic oscillators, where the interaction of the nodes is defined by coupling only one state of eachFO oscillator.

Nonlinear Analysis of Electroencephalogram in Schizophrenia Patients with Persistent Auditory Hallucination

이승환,Jung- Suk Choo,Wu-Young Im,채정호 대한신경정신의학회 2008 PSYCHIATRY INVESTIGATION Vol.5 No.2

Objective: The recent nonlinear analyses of electroencephalogram (EEG) data have shown that the correlation dimension (D2) reflects the degree of integration of information processing in the brain. There is now considerable evidence that auditory hallucination (AH) reflects dysfunctional gamma and beta frequency oscillations. Gamma oscillations are thought to reflect internally driven representations of objects, and the occurrence of ubsequent beta oscillations can reflect the modification of the neuronal circuitry used to encode the sensory perception. The purpose of this study was to test whether AH in schizophrenia patients is reflected in abnormalities in D2 in their EEG, especially in the gamma and beta frequency bands. Methods: Twenty-five schizophrenia patients with a history of treatment-refractory AH over at least the past 2 years, and 23 schizophrenia patients with no AH (N-AH) within the past 2 years were recruited for the study. Artifact-free 30-s EEG epochs during rest were examined for D2. ResultsᄏThe AH patients showed significantly increased gamma frequency 2 in Fp2 and decreased beta frequency D2 in the P3 region compared with the N-AH patients. These results imply that gamma frequency D2 in the right prefrontal cortex is more chaotic and that beta frequency D2 in the left parietal cortex is more coherent (less chaotic) in AH patients than in N-AH patients. Conclusion: Our study supports the previous evidence indicating that gamma nd beta oscillations are pivotal to AH, and also shows the distinctive imensional complexity between the right prefrontal and left parietal cortexes as the underlying biological correlates of AH in schizophrenia patients.

분광타원법을 이용한 PDP용 ITO 박막의 패턴 분석

윤희삼,김상열 한국광학회 2003 한국광학회지 Vol.14 No.3

분광타원법을 이용하여 PDP용 ITO박막의 광학상수 및 패턴을 분석하였다. ITO 박막의 광물성은 로렌쯔 진동자 모델을 사용하고 ITO의 패턴에 의한 효과는 전체빔이 ITO와 유리기층을 덮는 면적비 가중치를 가진 반사율 평균방법으로 반영시켰다. PDP 다층박막을 구성하고 있는 유리기층 위의 ITO박막 패턴이 타원데이터에 미치는 영향을 분석하여 ITO가 패턴에서 차지하는 면적비를 결정하였다. 측정된 분광타원데이터에 최적맞춤한 ITO의 상대면적값이 예측값과 보이는 차이를 검토함으로써 분광타원법을 사용한 ITO패턴분석의 한계와 이를 극복하는 방법을 제시하였다. We studied patterned ITO layers of PDP thin films on glass substrates using spectroscopic ellipsometry. The optical property of ITO is expressed with the optical model based on two Lorentz oscillators. The effect of patterned ITO is calculated by taking the weighted average of reflectance in proportion to ITO coverage. The relative coverage of ITO is determined by using the model analysis of spectroellipsometric data. The difference of ITO coverage obtained by the best-fit model analysis of ellipsometric spectra to the expected one is critically examined and suggestions are made to minimize the observed discrepancy.

화학반응에서의 비선형 현상

허도성,신수범,김민석,김혜숙 인제대학교 1999 仁濟論叢 Vol.15 No.1

시간상에서 나타나는 화학반응에서의 비선형적 현상을 살펴본다. 주기적으로 진동하는 시스템과 복잡하게 진동하는 시스템에 대해 이론적 배경과 실험 결과, 그리고 활용 가능성에 대해 역사적 배경과 함께 고찰한다. We have studied the nonlinear phenomena in chemical reaction system. A historical and thermodynamic background about the nonlinear phenomena was considered at first, and we studied the chemical oscillations, complex chemical oscillation patterns, and chaos phenomena including the nonlinear phenomena of living system. Key Word : nonlinear dynamics, chemical oscillations, complex oscillations, chaos phenomena

광중합 복합레진의 중합초기 동적 점탄성의 변화

김민호,이인복 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.5

본 연구의 목적은 새로 개발한 점탄성 측정기를 사용하여 수종의 광중합 복합레진의 초기 동적 점탄성 변화를 측정하는 것이다. 본 연구에 사용된 점탄성 측정기는 세 부분으로 구성되었다. 첫째, 시편이 놓여지는 parallel plates; 둘째, DC 모터와 크랭크로 이루어진 회전진동전단변형 (Oscillatory shear strain)을 발생시키는 부분; 셋째, 전자기적 토크센서를 이용한 응력 측정 부분으로 구성되었다. 본 점탄성 측정기는 최대 2 Ncm의 토크를 측정할 수 있으며, 광중합기의 스위치는 컴퓨터와 연동하여 데이터 획득을 시작할 때 동시에 켜지도록 하였다. 본 연구에서는 시판 중인 6종의 광중합 복합레진 [Z-100 (Z1), Z-250 (Z2), Z-350 (Z3), DenFil (DF), Tetric Ceram (TC), Clearfil AP-X (CF)]을 사용하였다. 점탄성 측정기를 사용하여 동적 회전전단실험을 시행하였다. 직경 3 mm인 유리막대로 구성된 parallel plates 사이에 14.2㎣의 복합레진을 적용시켰으며, 6 Hz의 진동수와 0.00579 rad의 진폭으로 변형을 가하고 발생된 응력을 측정하였다. 광중합이 시작됨과 동시에 측정이 시작되었으며, 광중합 후 10초 동안 점탄성의 변화를 관찰하였다. 각 복합레진에 대해 5 회 반복하여 측정하였고, 실험은 에서 진행되었다. 측정된 변형-응력 곡선으로부터 복소전단탄성계수 G*, 저장전단탄성 계수 G', 손실전단탄성 계수 G"를 구하였고 G*가 10 MPa에 이르는 시간을 구하였다. 각 재료의 복소전단탄성계수 G*와 10 MPa에 이르는 시간에 대해 일원분산분석 (One-way ANOVA)과 사후검정 (Tukey 검정)을 시행하였다 (α= 0.05). 결과는 다음과 같다. 1. 본 연구를 위해 제작한 점탄성 측정기는 광중합 복합레진의 중합 초기 10초 동안의 동적 점탄성 변화를 신뢰성 있게 측정 할 수 있었다. 2. 모든 복합레진은 광조사 개시 후 초의 불응기를 지난 다음 급격한 전단탄성계수의 증가를 보였다. 3. 모든 복합레진은 광중합 10 초간 손실전단탄성계수보다 저장전단탄성계수의 높은 증가를 보였다. 4. 광중합 초기 10초 후 복소전단탄성계수 값은 로, Z-100이 가장 높았고, 그 다음 Clearfil, Z-250, Z-350, Tetric Ceram, DenFil의 순이었다. 5. 복소전단탄성계수가 10 MPa에 이르는 시간은 Z-100이 2.55초로 가장 빨랐고, DenFil이 4.06초로 가장 느렸다. The aim of this study was to measure the initial dynamic modulus changes of light cured composites using a custom made rheometer. The custom made rheometer consisted of 3 parts: (1) a measurement unit of parallel plates made of glass rods, (2) an oscillating shear strain generator with a DC motor and a crank mechanism, (3) a stress measurement device using an electromagnetic torque sensor. This instrument could measure a maximum torque of 2Ncm, and the switch of the light-curing unit was synchronized with the rheometer. Six commercial composite resins [Z-100 (Z1), Z-250 (Z2), Z-350 (Z3), DenFil (DF), Tetric Ceram (TC), and Clearfil AP-X (CF)] were investigated. A dynamic oscillating shear test was undertaken with the rheometer. A certain volume (14.2 ㎣) of composite was loaded between the parallel plates, which were made of glass rods (3 mm in diameter). An oscillating shear strain with a frequency of 6 Hz and amplitude of 0.00579 rad was applied to the specimen and the resultant stress was measured. Data acquisition started simultaneously with light curing, and the changes in visco-elasticity of composites were recorded for 10 seconds. The measurements were repeated 5 times for each composite at . Complex shear modulus G*, storage shear modulus G', loss shear modulus G" were calculated from the measured strain-stress curves. Time to reach the complex modulus G* of 10 MPa was determined. The G* and time to reach the G* of 10 MPa of composites were analyzed with One-way ANOVA and Tukey's test (α = 0.05). The results were as follows. 1. The custom made rheometer in this study reliably measured the initial visco-elastic modulus changes of composites during 10 seconds of light curing. 2. In all composites, the development of complex shear modulus G* had a latent period for seconds immediately after the start of light curing, and then increased rapidly during 10 seconds. 3. In all composites, the storage shear modulus G" increased steeper than the loss shear modulus G" during 10 seconds of light curing. 4. The complex shear modulus of Z1 was the highest, followed by CF, Z2, Z3, TC and DF the lowest. 5. Z1 was the fastest and DF was the slowest in the time to reach the complex shear modulus of 10 MPa.

THE FUNCTION ANALYTIC IN THE EXTERIOR OF A DISC AND ITS APPLICATION TO PERIODIC COMPLEX OSCILLATION

Chen, Zong-Xuan,Gao, Shi-An Korean Mathematical Society 2013 대한수학회보 Vol.50 No.5

We consider the value distribution of a class of the functions analytic in the exterior of a disc and their applications to complex oscillation theory of differential equations with periodic coefficients in the complex plane.

The function analytic in the exterior of a disc and its application to periodic complex oscillation

Zong-Xuan Chen,Shi-an Gao 대한수학회 2013 대한수학회보 Vol.50 No.5

We consider the value distribution of a class of the functions analytic in the exterior of a disc and their applications to complex oscillation theory of differential equations with periodic coefficients in the complex plane.

On the Complexity of a Charged Quantum Oscillator

Pirmoradian Reza,Tanhayi Mohammad Reza 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.2

In this paper, we study the effect of both the electric and the magnetic fields on the rate of complexity growth. Our system is a charged quantum oscillator and over a period of time, we study the maximum dynamic evolution of quantum states which might lead to a strong bound on the rate of computation. We show that by turning on the electric field, the rate of complexity decreases whereas this rate has increasing behavior when the magnetic field is turned on. In this regard, we also find a critical value of the magnetic field, beyond which this rate changes its behavior drastically.

Soil interaction effects on the performance of compliant liquid column damper for seismic vibration control of short period structures

Ratan Kumar Ghosh,Aparna (Dey) Ghosh 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.1

The paper presents a study on the effects of soil-structure-interaction (SSI) on the performance of the compliant liquid column damper (CLCD) for the seismic vibration control of short period structures. The frequency-domain formulation for the input-output relation of a flexible-base structure with CLCD has been derived. The superstructure has been modeled as a linear, single degreeof-freedom (SDOF) system. The foundation has been considered to be attached to the underlying soil medium through linear springs and viscous dashpots, the properties of which have been represented by complex valued impedance functions. By using a standard equivalent linearization technique, the nonlinear orifice damping of the CLCD has been replaced by equivalent linear viscous damping. A numerical stochastic study has been carried out to study the functioning of the CLCD for varying degrees of SSI. Comparison of the damper performance when it is tuned to the fixed-base structural frequency and when tuned to the flexible-base structural frequency has been made. The effects of SSI on the optimal value of the orifice damping coefficient of the damper has also been studied. A more convenient approach for designing the damper while considering SSI, by using an established model of a replacement oscillator for the structure-soil system has also been presented. Finally, a simulation study, using a recorded accelerogram, has been carried out on the CLCD performance for the flexible-base structure.

Soil interaction effects on the performance of compliant liquid column damper for seismic vibration control of short period structures

Ghosh, Ratan Kumar,Ghosh, Aparna Dey Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.1

The paper presents a study on the effects of soil-structure-interaction (SSI) on the performance of the compliant liquid column damper (CLCD) for the seismic vibration control of short period structures. The frequency-domain formulation for the input-output relation of a flexible-base structure with CLCD has been derived. The superstructure has been modeled as a linear, single degreeof-freedom (SDOF) system. The foundation has been considered to be attached to the underlying soil medium through linear springs and viscous dashpots, the properties of which have been represented by complex valued impedance functions. By using a standard equivalent linearization technique, the nonlinear orifice damping of the CLCD has been replaced by equivalent linear viscous damping. A numerical stochastic study has been carried out to study the functioning of the CLCD for varying degrees of SSI. Comparison of the damper performance when it is tuned to the fixed-base structural frequency and when tuned to the flexible-base structural frequency has been made. The effects of SSI on the optimal value of the orifice damping coefficient of the damper has also been studied. A more convenient approach for designing the damper while considering SSI, by using an established model of a replacement oscillator for the structure-soil system has also been presented. Finally, a simulation study, using a recorded accelerogram, has been carried out on the CLCD performance for the flexible-base structure.