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911.
M. A. Geday D. P. Medialdea B. Cerrolaza N. Bennis X. Quintana J. M. Otón 《Opto-Electronics Review》2009,17(2):140-143
The ferroelectric-antiferroelectric transition in greyscale generation of antiferroelectric liquid crystal displays (AFLC)
is a heterogeneous process. The process has been described as the growth of finger-like domains [1]. We have previously studied
the ferroelectric-antiferroelectric phase transition, relaxation that follows the data pulse in surface stabilized asymmetric
antiferroelectric liquid crystal displays using biasless video frequency waveforms [2]. This relaxation involves an intensity
decay of the light transmitted by a pixel and depends on several parameters such as surface stabilization, rotational viscosity
of the AFLC, magnitude of the data pulse, and bias voltage.
The usual multiplexed driving of AFLC displays leads to long-term stabilisation of the grey levels induced by the data pulses
within the selection time. However, depending on the bias level, alternative greyscale mechanisms may be obtained by allowing
the grey levels to decay during the frametime. These greyscales may be advantageous in some instances since they improve the
dynamic response of the AFLC device and reduce the reset time of the waveform.
In this study we extend the previous work to include the effect of bias. We present the measured data, in terms of growth
pattern and speed and present an extension of the previously model on order to explain the results. 相似文献
912.
Hui Zhang Ming-Li Xiang Chang-Ying Ma Qi Huang Wei Li Yang Xie Yu-Quan Wei Sheng-Yong Yang 《Molecular diversity》2009,13(2):261-268
In this investigation, three-class classification models of aqueous solubility (logS) and lipophilicity (logP) have been developed
by using a support vector machine (SVM) method combined with a genetic algorithm (GA) for feature selection and a conjugate
gradient method (CG) for parameter optimization. A 5-fold cross-validation and an independent test set method were used to
evaluate the SVM classification models. For logS, the overall prediction accuracy is 87.1% for training set and 90.0% for
test set. For logP, the overall prediction accuracy is 81.0% for training set and 82.0% for test set. In general, for both
logS and logP, the prediction accuracies of three-class models are slightly lower by several percent than those of two-class
models. A comparison between the performance of GA–CG–SVM models and that of GA–SVM models shows that the SVM parameter optimization
has a significant impact on the quality of SVM classification model.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Hui Zhang and Ming-Li Xiang are contributed equally. 相似文献
913.
A four-party scheme is put forward for a sender to partition arbitrary single-qubit information among three receivers by utilizing a class of asymmetric four-qubit W state as quantum channels. In the scheme the sender's quantum information can be recovered by the three receivers if and only if they collaborate together. Specifically, they collaborate to perform first two different 2-qubit collective unitary operations and then a single-qubit unitary operation. The scheme is symmetric and (3, 3)-threshold with regard to the reconstruction, for any receiver can be assigned to conclusively recover the quantum information with the other two's assistances. 相似文献
914.
Discrete fractional Hadamard transform (DFrHaT) is a generalization of the Hadamard transform, which has been widely used in signal processing. In this paper, we present the multiple-parameter discrete fractional Hadamard transform (MPDFrHaT), which has multiple order parameters instead of only one in DFrHaT. The proposed MPDFrHaT is shown to possess all of the desired properties of DFrHaT. In fact, it will reduce to DFrHaT when all of its order parameters are the same. We also propose a novel encryption technique, double random amplitude (DRA) encoding scheme, by cascading twofold random amplitude filtering. As a primary application, we exploit the multiple-parameter feature of MPDFrHaT and double random amplitude encoding scheme for digital image encryption in the MPDFrHaT domain. Results show that this method can enhance data security. 相似文献
915.
An algorithm of free-form lens design is presented that can realize wide-angle imaging in conjunction with conventional imaging devices. The wide-angle image obtained through the free-form lens and the camera is not affected by distortions. The formula for the free-form lens surfaces is derived. The surface profile of the free-form lens can be generated through solving a differential equation expressing the camera-viewing angle as a function of the angle of incidence on the free-form lens surface. The surfaces preserve a linear relationship between the angle of incidence of light onto the surface and the angle of refraction into the imaging device. 相似文献
916.
In this paper a dual-compact scheme, which accommodates a better dispersion relation for the convective terms shown in the transport equation, is proposed to enhance the convective stability of the convection–diffusion equation by virtue of the increased dispersive accuracy. The dispersion-relation-preserving compact scheme has been rigorously developed within the three-stencil point framework through the dispersion and dissipation analyses. To verify the proposed method, several problems that are amenable to the exact and benchmark solutions will be investigated. The results with good rates of convergence are demonstrated for all the investigated problems. 相似文献
917.
A high-order numerical method for the nonlinear Helmholtz equation in multidimensional layered media
We present a novel computational methodology for solving the scalar nonlinear Helmholtz equation (NLH) that governs the propagation of laser light in Kerr dielectrics. 相似文献
918.
G. Carré S. Del PinoB. Després E. Labourasse 《Journal of computational physics》2009,228(14):5160-5183
We describe a cell-centered Godunov scheme for Lagrangian gas dynamics on general unstructured meshes in arbitrary dimension. The construction of the scheme is based upon the definition of some geometric vectors which are defined on a moving mesh. The finite volume solver is node based and compatible with the mesh displacement. We also discuss boundary conditions. Numerical results on basic 3D tests problems show the efficiency of this approach. We also consider a quasi-incompressible test problem for which our nodal solver gives very good results if compared with other Godunov solvers. We briefly discuss the compatibility with ALE and/or AMR techniques at the end of this work. We detail the coefficients of the isoparametric element in the appendix. 相似文献
919.
1、引言 对流扩散方程是描述粘性流体运动的非线性方程的线性化模型方程,而且它本身也描述了许多自然现象,例如在水中或大气中污染物质浓度的扩散,沿海盐度,温度扩散等等.因此求解对流扩散方程的计算方法特别是并行解法引起了充分的重视。 相似文献
920.