Seed region selection and homogeneity criterion for doorplate image segmentation in mobile robot navigation

Focused on the seed region selection and homogeneity criterion in Seeded Region Growing （SRG）, an unsupervised seed region selection and a polynomial fitting homogeneity criterion for SRG are proposed in this paper. First of all, making use of Peer Group Filtering （PGF） techniques, an unsupervised seed region selection algorithm is presented to construct a seed region. Then based on the constructed seed region a polynomial fitting homogeneity criterion is applied to solve the concrete problem of doorplate segmentation appearing in the robot navigation along a corridor. At last, experiments are performed and the results demonstrate the effectiveness of the proposed algorithm.     

配电变压器额定电流近似值速算法

电力系统中,配电变压器数量非常之多,所占地位也非常重要。在现场常需求出配电变压器的一、二次额定电流,以便更换熔丝、熔管、开关、电流互感器和导线等。额定电流可以用公式计算出来,但比较费时。在实际工作中,我们根据已知的变压器相数、额定容量、一、二次额定电压,可立即求出额定电流近似值,其精确度能满足要求。这种方法简单易行,很适合现场应用,现将此方法的推算介绍如下。     

基于硬币实验的圆周率近似值计算

圆周率π的近似值计算,历史悠久,公式繁多.本文从硬币实验出发,运用数列极限知识让学生亲历体验π的近似值计算过程,领悟思想方法,感受数学魅力。     

基于MPS的任意变形蒙皮

针对利用MPS驱动的骨骼蒙皮动画对于非关节的对象精度不高的问题,提出了基于MPS的任意变蒙皮(SAD),该技术在任意动画上设置代理关节,自动为预先处理的任意动画的每一帧构建蒙皮相似量,利用二重四元数蒙皮,实验表明,SAD不仅能够有效地驱动非关节元素对象提高精度,而且能够充分利用MPS的优点.     

基于MPS的任意变形蒙皮

针对利用MPS驱动的骨骼蒙皮动画对于非关节的对象精度不高的问题，提出了基于MPS的任意变蒙皮（SAD），该技术在任意动画上设置代理关节，自动为预先处理的任意动画的每一帧构建蒙皮相似量，利用二重四元数蒙皮，实验表明，SAD不仅能够有效地驱动非关节元素对象提高精度，而且能够充分利用MPS的优点．     

浅析程序设计在解决与近似值相关的数学问题上的应用

本文将程序设计知识运用到求无理数的近似值、求解方程的近似根、求不规则图形面积等与近似值相关的数学问题上,让读者从新的角度审视求解与近似值相关的数学问题的新方法,并领悟程序设计在求解决这些数学问题上所显示出的优势。     

A New Weighted Least Squares Support Vector Machines and Its Sequential Minimal Optimization Algorithm

Least squares support vector machines （LSSVM） is widely used in pattern recognition and artificial intelligence domain in recent years for its efficiency in classification and regression. The solution of LSSVM is an optimization problem of a Sum squared error （SSE） cost function with only equality constraints and can be solved in a simple linear system. However, its generalization performance is sensitive to noise points and outliers that are often existent in training dataset. In order to endow robustness to LSSVM, a new method for computing weight vector of error is proposed and the substituting of weighted error vector for original error vector in LSSVM gives birth to a new weighted LSSVM. The method gets weight factor by computing distance between sample and its corresponding class center. Sequential minimal optimization （SMO） algorithm is also extended to the new method for its efficient application. Comparison experiments show superiority of the new method in terms of generalization performance, robust property and sparse approximation. Especially, the new method is much faster than the other method for large number of samples.     

Verification of duration systems using an approximation approach

We consider the verification problem of invariance properties for timed systems modeled by (extended) Timed Graphs with duration variables,This problem is in general case undecidable,Nevertheless we give in this paper a technique extending a given system into another one containing the initial computations as well as additional ones.Then we define a digitization technique allowing the translation from the continuous case to the discrete one.Using this digitization,we show that to each real computation in the initial system corresponds a discrete computation in the extended system.Then,we show that the extended system corresponds to a very close approximation of the initial one,allowing per consequent,a good analysis of invariance properties of the initial system.     

雷达角度分辨率

雷达角度分辨率(radar angular resolution)雷达在角度上,从毗邻目标的回波中．区分出各个目标信号的能力。通常以能区分出在相同距离、同样回波信号强度的二目标．所需的目标间最小方位角或仰角问题,来表示雷达的角度分辨率。雷达角度分辨率的数字度量的近似值为雷达天线波束的半功率点波束宽度。实际上由于二毗邻目标间相对相位关系不同,可获得的雷达角度分辨率的范围为1～2倍的天线波束半功率点间的宽度．典型值为1．5倍天线波束半功率点间的宽度。     

镁橄榄石电场梯度张量的重新计算

为了用一个无参数模式获得镁橄榄石所有晶核的电场梯度,提出了一个以密度函数为基础的能带结构重新计算方法。用广义梯度近似值法得到的~(25)Mg 的 V_(zz)与由实验值获得的 V_(zz)相差最大为1%,~(17)O 为2%。如果在换算中使用核四极矩动量值,则绝对值相差约为5%,不对称参数与实验值也相当一致。用一个校正梯度相关互换位势取得的不对称参数值,比用标准局部密度近似值法获得的值要好。四极矩耦合张量的主轴与结晶轴之间的夹角也与实验值相吻合。M1位最大的偏差为1.8°,M2位为0.6°。该计算可以用于评价~(17)O 电场梯度的3组实验数据。所有计算同时也明确提出了一种测定特定 O 原子电场梯度的方法。