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101.
Lingzhi Zhao Jinde Cao Chengdai Huang Ahmed Alsaedi Abdullah Al-Barakati Habib M. Fardoun 《International Journal of Control, Automation and Systems》2017,15(3):1134-1144
The issue of bifurcation control for a delayed fractional network involving two neurons is concerned. Delay-dependent stability conditions and the bifurcation point are established by discussing the associated characteristic equation of the proposed network. Then, a delayed feedback controller is firstly designed to stabilize the Hopf bifurcation, and desirable dynamics is achieved. It is indicated that the designed controller is extremely effective which can postpone the onset of bifurcation by carefully selecting the feedback gain. Finally, simulation results are given to verify the efficiency of the theoretical results. 相似文献
102.
在公共场所中人们都倾向于以分组的形式进行运动,本文把这种以分组形式运动的若干个行人称为运动群组,具有视觉显著性的人群运动群组是场景理解的重点,其对人群的整体运动也影响最大。本文对运动群组的视觉显著性展开了研究,分别从规模、速度、组内紧致度和变化度4个方面来对运动群组的视觉显著性进行度量,并基于该度量给出了视觉显著性运动群组检测方法。首先,利用光流法对运动人群进行分析得到光流向量;然后通过层次聚类算法对运动人群进行分组;最后,基于本文所给出的度量计算每个群组的视觉显著性,以检测出视觉显著性最高的运动群组。实验表明该方法能够有效地对视觉显
著性运动群组进行检测,该研究成果可应用于人群场景理解、人群运动分析和人群场景分类等计算机视觉研究领域。 相似文献
103.
A shape prior constraint for implicit active contours 总被引:2,自引:0,他引:2
We present a shape prior constraint to guide the evolution of implicit active contours. Our method includes three core techniques. Firstly, a rigid registration is introduced, using a line search method within a level set framework. The method automatically finds the time step for the iterative optimization processes. The order for finding the optimal translation, rotation and scale is derived experimentally. Secondly, a single reconstructed shape is created from a shape distribution of a previously acquired learning set. The reconstructed shape is applied to guide the active contour evolution. Thirdly, our method balances the impact of the shape prior versus the image guidance of the active contour. A mixed stopping condition is defined based on the stationarity of the evolving curve and the shape prior constraint. Our method is completely non-parametric and avoids taking linear combinations of non-linear signed distance functions, which would cause problems because distance functions are not closed under linear operations. Experimental results show that our method is able to extract the desired objects in several circumstances, namely when noise is present in the image, when the objects are in slightly different poses and when parts of the object are invisible in the image. 相似文献
104.
从天然氨基酸的50个性质参数中经主成分分析得出1种新的氨基酸描述子:氨基酸特征性质得分.并在此基础上通过定义基于向量形式的自相关函数以及引入Mercer核技术将该函数运算空间进行非线性变换,最终提出了1种新的蛋白质序列表征方法:核序列自相关函数.采用该函数对632个已知晶体结构的非同源蛋白分类研究结果表明:KSACF能... 相似文献
105.
106.
介绍了飞行指挥模拟器的起落方程、飞行空中方程和特情调度方程等的设计与求解方法,该方法实现了对各种飞行情况的习行指挥调度训练的评分与打印。实际运行结果表明,本文介绍了方法具有飞行指挥调度训练灵活、训练评分准确有效、训练员操作简便以及用户界面友好等优点。 相似文献
107.
Shih Hao Huang Hwa Seng Khoo Shang Yu ChangChien Fan Gang Tseng 《Microfluidics and nanofluidics》2008,5(4):459-468
Monodisperse copolymer particles carrying surface carboxyl groups in the range of 50–200 μm were prepared by in situ UV polymerization
of ethyleneglycol dimethacrylate (EGDMA) with acrylic acid (AA) via a microfluidic flow-focusing device (MFFD). The design
of the coaxial orifices in the MFFD enables the confinement of the comonomer liquid thread to the central axis of the microchannel,
which can avoid the wetting problem of comonomer liquid with the microchannel and can successfully produce monodisperse copolymer
microspheres with coefficient of variance below 5%. The effects of concentration of EGDMA and AA on droplet diameters and
the distribution of carboxyl group on particle surfaces were examined. It has been found that, increasing the concentration
of AA would decrease particle sizes, but increase the distribution of carboxyl group on particle surfaces. Bioconjugation
of the carboxylated copolymer particles with the anti-rabbit IgG–Cy3 conjugates was successfully demonstrated. By increasing
the concentration of AA accompanied with decreasing the particle sizes, high efficiency of bioconjugation on carboxylated
copolymer particles was achieved. The rapid continuous synthesis of carboxylated copolymer particles via a microfluidic device
provides a reliable control of particle sizes and composition for massive production in biotechnological applications. 相似文献
108.
Shang L Jasiobedzki P Greenspan M 《IEEE transactions on pattern analysis and machine intelligence》2007,29(6):976-989
A method is presented for tracking 3D objects as they transform rigidly in space within a sparse range image sequence. The method operates in discrete space and exploits the coherence across image frames that results from the relationship between known bounds on the object's velocity and the sensor frame rate. These motion bounds allow the interframe transformation space to be reduced to a reasonable and indeed tiny size, comprising only tens or hundreds of possible states. The tracking problem is in this way cast into a classification framework, effectively trading off localization precision for runtime efficiency and robustness. The method has been implemented and tested extensively on a variety of freeform objects within a sparse range data stream comprising only a few hundred points per image. It has been shown to compare favorably against continuous domain iterative closest point (ICP) tracking methods, performing both more efficiently and more robustly. A hybrid method has also been implemented that executes a small number of ICP iterations following the initial discrete classification phase. This hybrid method is both more efficient than the ICP alone and more robust than either the discrete classification method or the ICP separately 相似文献
109.
110.
分析了沂沭泗河流域治理规划要求和60年来防洪工程建设现状,指出解决沂、沭、泗河中下游洪水出路问题是一项系统工程,目前中下游重要防护区和重要城市防洪标准要求总体达到了50年一遇,但骨干河道上游段堤防矮小、防洪标准不足20年一遇,湖东堤保护区范围内重要厂矿企业区部分堤段防洪标准亦不足50年一遇,另外部分城区段设防标准较低。这些现状与山东沂沭泗河流域作为省委省政府提出的"一体两翼"经济发展战略中的南翼———鲁南经济带的地位不相称,针对未来经济社会发展对其防洪保障的更高要求,提出了规划设想。 相似文献