“声现象”检测题     

袁菲菲 《初中生世界(初三物理版)》2011,(Z5)

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怎样标好光路图中的箭头     

王凯 《初中生世界(初三物理版)》2011,(Z6)

在光路图中标注箭头看似是个比较简单的问题,但是许多同学在解题时往往因为漏标箭头或者标错箭头而失分.光路图中凡是表示光的真实传播路径时都必须标注箭头,不是表示光的真实传播路径  相似文献   

无理函数值域一例五法     

胡良星 《数理天地(高中版)》2011,(11):14-14

对于形如 “f（x）=pax＋b＋qc-dx” 的函数的值域问题,同学们往往束手无策,下面就举例说明这类题目的解法．  相似文献   

小题求解简法     

任忠亮 《数理天地(高中版)》2011,(7):15-16

1．特殊值法 例1设函数f（x）在R上的导函数为f’（x）,且2f（x）＋xf′（x）〉x2,下面的不等式在R内恒成立的是（ ）  相似文献   

三角函数图象与其它曲线的融合     

安振平  韩小平 《数理天地(高中版)》2011,(10):7-7

1．正切函数与一次函数 例1 设点P（x0,y0）是函数y=tanx与y=-x图象的交点,求（x02＋1）（cos2x0＋1）的值．  相似文献   

抽象函数的定义域     

张思清 《数理天地(高中版)》2011,(3):3-3

函数的定义域是指函数自变量的取值集合．已知解析式的函数的定义域是使解析式有意义的自变量的取值集合．函数的解析式未知的抽象函数的定义域如何求呢？下面举例说明．  相似文献   

奇函数性质的6个应用     

徐加生 《数理天地(高中版)》2011,(11):1-2

1．求函数值 例1 已知函数f（x）=x5＋ax3＋bx-8,且f（-2）=10,则f（2）=__.  相似文献   

探究点、直线的对称     

洪联平 《数理天地(高中版)》2011,(12):7-7,9

1．中心对称 （1）点关于点对称 一个已知点（x0,y0）关于原点对称的点的坐标为（-x0,-y0）,点（x0,y0）关于点（a,b）对称的点坐标为（2a-x0,2b-y0）,其中点关于原点对称仅是一个特例．  相似文献   

Length-based vehicle classification in multi-lane traffic flow     

于洋  于明  阎刚  翟艳东 《天津大学学报(英文版)》2011,17(5):362-368

For the realtime classification of moving vehicles in the multi-lane traffic video sequences, a length-based method is proposed. To extract the moving regions of interest, the difference image between the updated background and current frame is obtained by using background subtraction, and then an edge-based shadow removal algorithm is implemented. Moreover, a thresholding segmentation method for the region detection of moving vehicle based on location search is developed. At the estimation stage, a registration line is set up in the detection area, then the vehicle length is estimated with the horizontal projection technique as soon as the vehicle leaves the registration line. Lastly, the vehicle is classified according to its length and the classification threshold. The proposed method is different from traditional methods that require complex camera calibrations. It calculates the pixel-based vehicle length by using uncalibrated traffic video sequences at lower computational cost. Furthermore, only one registration line is set up, which has high flexibility. Experimental results of three traffic video sequences show that the classification accuracies for the large and small vehicles are 97.1% and 96.7% respectively, which demonstrates the effectiveness of the proposed method.  相似文献   

Stabilization of Delayed Networks with Different Nodes     

徐君群  唐万生  张建雄 《天津大学学报(英文版)》2011,17(2):151-156

In this paper,the control of complex delayed networks with different nodes is proposed.Firstly,the stabilization of coupled networks with time delay is investigated.By constructing a Lyapunov function,a linear feedback controller design procedure for the networks is converted to the problem of solving a set of linear matrix inequalities.Then the results are extended to networks with both delayed dynamical nodes and delayed couplings.It is shown that the stabilization of complex networks is determined by the dynamics of each uncoupled node,coupling matrix and feedback gain matrix of networks.Two examples are simulated.In the first example,a network with 10 nodes consisting of Lorenz systems and systems proposed by Zhang in 2009 is given.It is found that the network states are divergent without control,and convergent under designed linear feedback controllers.In the second example,a larger network with 100 nodes consisting of delayed Chen systems and delayed Lorenz systems is given.The proposed method is also effective for large scale networks.  相似文献