Middle Pleistocene mammalian fauna of Shanyangzhai cave in Qinhuangdao area,China and its zoogeographical significance

The mammalian fauna with clear characteristics of transitional region has been found in the Shanyangzhai cave of the Qin-huangdao area where the three Chinese zoogeographical regions (the Northeast region, the North region and the Mengxin region) join. Abundant fossils mainly are small mammals. The fauna includes typical species derived from three zoogeographical regions and can be compared with the middle Pleistocene faunas found in both the Zhoukoudian (the North region) and the Jinniushan (the Northeast ...     

Effects of ytterbium on outward K<Superscript>+</Superscript> currents in NIH3T3 cell

Using the whole cell patch-clamp technique, we observed the outward K+ currents and studied for the first time the effects of Yb3+ on the currents and kinetics of activation and inactivation in non-excitable NIH3T3 cell. Our results show that the outward K+ currents were promoted with increasing concentration of Ca2+ in pipette solution and saturated at the concentration of 100 μmol/L Ca2+. Yb3+ in bath solution inhibited the currents in a concentration-dependent manner. At the concentration of 1 μmol/L, Yb...     

Output-feedback adaptive stochastic nonlinear stabilization using neural networks

For the first time, an adaptive backstepping neural network control approach is extended to a class of stochastic nonlinear output-feedback systems. Different from the existing results, the nonlinear terms are assumed to be completely unknown and only a neural network is employed to compensate for all unknown nonlinear functions so that the controller design is more simplified. Based on stochastic LaSalle theorem, the resulted closed-loop system is proved to be globally asymptotically stable in probability....     

Hooke and Jeeves algorithm for linear support vector machine

Coordinate descent method is a unconstrained optimization technique. When it is applied to support vector machine (SVM), at each step the method updates one component of w by solving a one-variable sub-problem while fixing other components. All components of w update after one iteration. Then go to next iteration. Though the method converges and converges fast in the beginning, it converges slow for final convergence. To improve the speed of final convergence of coordinate descent method, Hooke and Jeeves a...     

Fast segmentation approach for SAR image based on simple Markov random field

Traditional image segmentation methods based on MRF converge slowly and require pre-defined weight. These disadvan-tages are addressed, and a fast segmentation approach based on simple Markov random field (MRF) for SAR image is proposed. The approach is firstly used to perform coarse segmentation in blocks. Then the image is modeled with simple MRF and adaptive variable weighting forms are applied in homogeneous and heterogeneous regions. As a result, the convergent speed is accelerated while the segmentati...     

基于双目视觉的移动机器人动态目标识别与定位

提出了一种双目移动机器人实时动态目标识别与定位方法。该算法首先采用SIFT(Scale Invariant Features Transforms)算法提取目标特征,并结合双目视差特征进行目标匹配;然后通过区域增长方法进行目标区域的提取;最后结合双目视觉标定的模型对目标进行定位。实验结果表明:该方法在摄像机运动-目标运动情况下,能对局部特征未知或特征不明显的动态目标进行有效的识别与定位。     

苯乙烯-甲基丙烯酸酯系二元共聚树脂的吸油性能

采用悬浮聚合法,以BPO为引发剂,DVB为交联剂,HEC为分散剂,甲苯为成孔剂,合成了苯乙烯分别与甲基丙烯酸甲酯、甲基丙烯酸丁酯、甲基丙烯酸十二酯的二元共聚树脂.研究了反应时间及温度、引发剂、交联剂、分散剂、原料配比、烷基酯的长度对树脂吸油性能的影响.所制得的树脂对甲苯的吸油率分别可达9g/g、12g/g、14g/g,对乙酸乙酯的吸油率分别可达7.8g/g、8.4g/g、10.5g/g.在显微镜下对树脂吸油前后的内部微观结构进行了观察对比.     

基于自适应的小波阈值和GTEO进行说话人识别

小波压缩是基于小波系数的阈值的一个简单去噪方法.它对于所有的含噪语音,都使用一致的阈值,不仅压缩了噪声,也压缩了部分语音成分,因此滤掉的语音感知质量会受到极大的影响.在小波去噪过程中采用了自适应阈值小波包方法.同时把小波去噪和推广的TEO结合起来,去提高系数的鲁棒性.为了进一步提高识别率,在识别阶段,采用改进的MCE算法.实验结果显示,提出的方法取得了较好的效果.     

基于群体评价信息集结的中层管理者绩效考评研究

针对中层管理者的绩效考评问题,从多层次、多角度出发,建立了基于群体评价信息集结的绩效考评体系.具体的做法是:将各评价者的个体评价信息映射到二维平面坐标系中,利用Steiner点的概念,采用模拟植物生长算法(PGSA)求出群体评价的最优信息集结值,并计算评价主体的综合权重,进而求出带权重的综合最优集结评价值,以此对中层管...     

一种针对高维决策空间的进化多目标优化方法

进化算法可并行处理多个解的特性使得它特别适合解决多目标优化问题。针对高维决策空间,将基因表达式编程引入多目标优化,设计了新的个体结构和操作,提出了一个进化多目标优化算法EMOGEP。实验结果表明,新算法在低维决策空间是可行和有效的;在高维决策空间中,表现出了比传统进化多目标优化算法更好的性能;多模态情况下,新算法能很好的逼近理论Pareto前沿。