• 제목/요약/키워드: complex variable

검색결과 739건 처리시간 0.026초

Synchronization in Complex Systems

  • Bae, Young-Chul;Kim, Chun-Suk;Koo, Young-Duk
    • Journal of information and communication convergence engineering
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    • 제2권4호
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    • pp.237-242
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    • 2004
  • In this paper, we introduce a complex systems synchronization method using hyper-chaos circuit consist of State-Controlled Cellular Neural Network (SC-CNN). We make a complex systems using SC-CNN with the n-double scroll. A complex system is created by applying identical n-double scroll or non-identical n-double scroll and Chua's oscillator with weak coupled method to each cell. Complex systems synchronization were achieved using GS(Generalized Synchronization) method between the transmitter and receiver about each state variable in the SC-CNN.

도시근교농촌 아파트 단지의 시각적 영향 -용인시를 대상으로- (The Visual Impacts of the Apartment Complex in Suburban Rural Area -The Case of Young-In City-)

  • 서주환;최현상;변성진;나혜진
    • 한국조경학회지
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    • 제28권1호
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    • pp.109-117
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    • 2000
  • The purpose of this study is to examine the effect factors in suburban rural landscape and significant factors of apartment complex which are effective to the skyline of the sloped mountains. Also it is to propose the basic resources to preserve and improve the suburban rural landscape. The target site is Young-In, which shows the typical of rural development. Sides were take in young-In City along the roads and selected for 20 pieces. This study used questionnaire about the suburban rural landscape surveying of 45 students in Kyunghee Univ.. Also we found 2 dependent variables and 8 independent variables totally. Moreover, we have analyzed the data using descriptive statistics, correlation analysis, and multiple linear regression method between the preference and physical factors, and between the vulnerability and perceptional factors. The results are as follows: 1) With the dependent variable of preference, the areas of "green space" and "agricultural productive lands" were highly influenced in the suburban rural landscape positively, but the areas of "apartment complex" and "other buildings" were negatively effected. 2) With the dependent variable vulnerability, the area "apartment complex" and cutting numbers of the "skyline of mountainous ridge" were proved as significantly positive factors, but the length of the "skyline of mountainous ridge" turned out to be a negative factor. Although this study has the difficulty to be generalized, it can be used for planning and designing of the apartment complex in suburban rural landscapes, and it will provide the basic guideline for preserving and managing of the suburban rural landscapes.uideline for preserving and managing of the suburban rural landscapes.

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감쇠계 고유치문제의 설계민감도해석을 위한 보조변수법 (An Adjoint Variable Method for Eigenproblem Design Sensitivity Analysis of Damped Systems)

  • 이태희;이진민;유정훈;이민욱
    • 대한기계학회논문집A
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    • 제29권11호
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    • pp.1527-1533
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    • 2005
  • Three methods for design sensitivity analysis such as finite difference method(FDM), direct differentiation method(DDM) and adjoint variable method(AVM) are well known. FDM and DDM for design sensitivity analysis cost too much when the number of design variables is too large. An AVM is required to compute adjoint variables from the simultaneous linear system equation, the so-called adjoint equation. Because the adjoint equation is independent of the number of design variables, an AVM is efficient for when number of design variables is too large. In this study, AVM has been extended to the eigenproblem of damped systems whose eigenvlaues and eigenvectors are complex numbers. Moreover, this method is implemented into a commercial finite element analysis program by means of the semi-analytical method to show applicability of the developed method into practical structural problems. The proposed_method is compared with FDM and verified its accuracy for analytical and practical cases.

유도기 효율향상을 위한 회전자슬롯 형상최적화 (Shape Design of Induction Motors for Efficiency Improvement)

  • 곽인구;이향범;박일한;한송엽
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.929-931
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    • 1993
  • The design sensitivity analysis based on the finite element method is presented for the eddy current problem with a voltage source. Since, in this problem, the complex variable is used as the state variable, new approach to the sensitivity calculation for the complex variable system is required. Its result is applied to the design of the rotor slot shape of squirrel cage induction motor. As a analysis model, only one slot pitch of rotor is analyzed by using a Periodic boundary condition. The use of this minimal modelling method leads to much saving of calculation time. The design objective is to obtain the desired slip-torque characteristic. Because the shape of rotor slot has much influence on the slip torque characteristic, the design variables are taken on the interface shape between rotor core and rotor bar. The initial shape of rotor slot is the trapezoidal type with rounding corners. The obtained final shape is quite similar to the double squirrel cage type.

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The analytic solution for parametrically excited oscillators of complex variable in nonlinear dynamic systems under harmonic loading

  • Bayat, Mahdi;Bayat, Mahmoud;Pakar, Iman
    • Steel and Composite Structures
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    • 제17권1호
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    • pp.123-131
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    • 2014
  • In this paper we have considered the vibration of parametrically excited oscillator with strong cubic positive nonlinearity of complex variable in nonlinear dynamic systems with forcing based on Mathieu-Duffing equation. A new analytical approach called homotopy perturbation has been utilized to obtain the analytical solution for the problem. Runge-Kutta's algorithm is also presented as our numerical solution. Some comparisons between the results obtained by the homotopy perturbation method and Runge-Kutta algorithm are shown to show the accuracy of the proposed method. In has been indicated that the homotopy perturbation shows an excellent approximations comparing the numerical one.

수직 균일 열유동하에 있는 접합 경계면 균열의 열응력세기계수 결정 (Determination of Thermal Dtress Intensity Factors for the Interface Crack under Vertical Uniform Heat Flow)

  • 이강용;설창원
    • 대한기계학회논문집
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    • 제15권1호
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    • pp.201-208
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    • 1991
  • 본 연구에서는 균일 열유동이 접합면에 수직으로 흐르고 접합 경계면 균열의 열경계조건이 단열되어 있는 경우에 균질 및 접합재료 모두에 적용될 수 있는 열응세 기계수를 복소해석방법을 이용하여 구하고자 한다.

Towards the Reconstruction of Time-dependent Vibronic States from Nonlinear Wavepacket Interferometry Signals

  • Humble, Travis S.;Cina, Jeffrey A.
    • Bulletin of the Korean Chemical Society
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    • 제24권8호
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    • pp.1111-1118
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    • 2003
  • We present one-color nonlinear wavepacket interferometry (WPI) signal calculations for a system of two electronic levels and one vibrational degree of freedom. We consider two cases, a displaced harmonic oscillator system, which can be treated analytically, and a model photodissociative system, whose WPI signal must be calculated by numerical wavepacket propagation. We show how signals obtained with different combinations of intrapulse-pair phase shifts can be combined to isolate the complex-valued overlap between a given onepulse target wavepacket and a variable three-pulse reference wavepacket. We demonstrate that with a range of inter- and intrapulse-pair delays the complex overlaps and variable reference states can be used to reconstruct the target wavepacket. We compare our results with previous methods for vibronic state reconstruction based on linear WPI and discuss further generalizations of our method.

극초단 펄스레이저 광이 입사된 금속박막의 열적반응 중 비정상반사율의 영향 (Effects of transient thermo reflectance on the thermal responses of metal thin film exposed to ultrashort laser heating)

  • 박승호;국정진
    • 설비공학논문집
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    • 제11권4호
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    • pp.528-536
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    • 1999
  • This work studies the effects of transient reflectance on the thermal responses of a metal(gold) thin-film during ultrashort laser heating. The heating process is calculated using the conventional conduction model (parabolic one-step: POS), parabolic two-step model (PTS) with and without variable properties, hyperbolic two-step model (HTS). Results from the HTS model are very similar to those from the PTS model, since the laser heating time in this study is greater than the electron relaxation time. PTS model with variable properties, however, results in totally different temperature profiles compared to those from POS models or calculation with constant properties. Transient reflectances are estimated from electron temperature distributions and based on the linear relationship between the electron temperature and complex dielectric constants. Reflectance of the front surface can be changed with respect to dielectric constants, while those of the rear surface remain unchanged.

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Neural Network Modeling of Hydrocarbon Recovery at Petroleum Contaminated Sites

  • Li, J.B.;Huang, G.H.;Huang, Y.F.;Chakma, A.;Zeng, G.M.
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.786-789
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    • 2002
  • A recurrent artificial neural network (ANN) model is developed to simulate hydrocarbon recovery process at petroleum-contaminated site. The groundwater extraction rate, vacuum pressure, and saturation hydraulic conductivity are selected as the input variables, while the cumulative hydrocarbon recovery volume is considered as the output variable. The experimental data fer establishing the ANN model are from implementation of a multiphase flow model for dual phase remediation process under different input variable conditions. The complex nonlinear and dynamic relationship between input and output data sets are then identified through the developed ANN model. Reasonable agreements between modeling results and experimental data are observed, which reveals high effectiveness and efficiency of the neural network approach in modeling complex hydrocarbon recovery behavior.

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An iteration approach for multiple notch problem based on complex variable boundary integral equation

  • Chen, Y.Z.
    • Structural Engineering and Mechanics
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    • 제41권5호
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    • pp.591-604
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    • 2012
  • This paper provides an iteration approach for the solution of multiple notch problem, which is based on the complex variable boundary integral equation (CVBIE). The contours of notches are applied by some loadings. The source points are assumed on the boundary of individual notch and the displacements along the boundaries become unknowns to be investigated. After discretization of the BIE, many influence matrices are obtained. One does not need to assemble many influence matrices into a larger matrix. This will considerably reduce the work in the program. The displacements along the many boundaries can be obtained from an iteration. There is no limitation for the configuration of notches. Several numerical examples are provided to prove the efficiency of the suggested approach.