基于改进蝙蝠优化自确定的模糊C-均值聚类算法

针对模糊C-均值聚类算法敏感于初始聚类中心及聚类收敛慢、聚类数目手动设定等缺陷,提出了基于改进蝙蝠优化自确定的模糊C-均值聚类算法。该算法是基于密度峰值综合衡量聚类中心外围数据密集程度和聚类中心间距离,自动确定聚类中心和聚类数目,以此作为改进蝙蝠算法的初始中心;在原始蝙蝠算法中引入Levy飞行特征加强算法跳出局部最优能力;使用Powell局部搜索加快算法的收敛,利用改进的蝙蝠种群进行种群寻优,并将最优蝙蝠位置作为聚类C-均值新聚类中心,进行模糊聚类,以此循环交叉迭代多次最终获得聚类结果。将基于改进蝙蝠优化自确定的模糊C-均值聚类算法与其它两种聚类算法在标准数据集上进行仿真对比,实验结果表明:与其它两种算法相比,该算法收敛速度快、误差率低。     

基于现场实测临海地区特大型冷却塔风振响应非平稳特性研究

忽视特大型冷却塔风振响应的非平稳特征可能会导致对结构响应极值的估算偏差和风振作用特性的错误理解。为此,以某沿海地区特大型冷却塔(高190 m)为研究对象,通过现场实测获取了超高雷诺数和真实湍流条件下特大型冷却塔的风振响应信号;在对实测信号进行降噪滤波处理后进行了不同时距的信号非平稳识别,并分别基于平稳分析模型和非平稳分析模型对特大型冷却塔的响应统计值、峰值因子和极值响应进行对比研究。研究结果表明:临海地区特大型冷却塔风振响应表现出较强的非平稳性,部分响应信号的"大偏斜"或"高峰态"现象是由非平稳特征引起,采用非平稳模型可以更有效地判别信号的真实非高斯特征;此外,响应峰值因子普遍大于3.5,忽视非平稳特性将导致极值估计的缺陷,既无法提供足够的保证率,又降低了响应极值计算结果的经济性。     

APPLICATION OF MAXIMUM ENTROPY PRINCIPLE METHOD TO THE STUDY OF WAVE CLIMATE STATISTICAL CHARACTERISTICS

The Maximum Entropy Principle (MEP) method is elaborated, and the corresponding probability density evaluation method for the random fluctuation system is introduced, the goal of the article is to find the best fitting method for the wave climate statistical distribution. For the first time, a kind of new maximum entropy probability distribution (MEP distribution) expression is deduced in accordance with the second order moment of a random process. Different from all the fitting methods in the past, the MEP distribution can describe the probability distribution of any random fluctuation system conveniently and reasonably. If the moments of the random signal is limited to the second order, that is, the ratio of the root-mean-square value to the mean value of the random variable is obtained from the random sample, the corresponding MEP distribution can be computed according to the deduced expression in this essay. The concept of the wave climate is introduced here, and the MEP distribution is applied to fit the probability density distributions of the significant wave height and spectral peak period. Take the Mexico Gulf as an example, three stations at different locations, depths and wind wave strengths are chosen in the half-closed gulf,the significant wave height and spectral peak period distributions at each station are fitted with the MEP distribution, the Weibull distribution and the Log-normal distribution respectively, the fitted results are compared with the field observations, the results show that the MEP distribution is the best fitting method, and the Weibull distribution is the worst one when applied to the significant wave height and spectral peak period distributions at different locations, water depths and wind wave strengths in the Gulf. The conclusion shows the feasibility and reasonability of fitting wave climate statistical distributions with the deduced MEP distributions in this essay, and furthermore proves the great potential of MEP method to the study of wave statistical properties.     

岩体抗剪强度单点试验法的研究与应用

岩体抗剪强度单点试验法，是一种既科学、又经济，即合理、又可靠的最新的宕体抗剪强度试验法，其精度已经过科研和生产实践所验证。单点试验法岩体破坏的机理是：在一定的法向荷载作用下，剪断面是依据不同部位岩体抗剪强度的大小逐次发生的，每一组荷载试验，均可获得一个“峰值特征点”，由数个特征点连结的τ－s和τ－σ曲线，是求取、C的主要依据。在剪断面上，爬坡角i的影响是一个重要因素。它能真实地反应实际地质体的力学特性。它与多点试验法成果相对比，差值甚小，完全有理由用单点试验法逐步取代多点试验法。     

黑龙江虎林先锋北山金矿床蚀变及矿床特征

先锋北山金矿床为产于白垩系下统皮克山组中酸性火山岩中的火山岩型金矿床。矿体赋存于强硅化碎裂斜长流纹岩、热液角砾岩，硅化带外侧依次为绢云母--泥化带、青盘岩化带。自然金与石英共生，说明金矿形成于热液活动的最后阶段。     

金属离子极谱峰电位的精确拟合解析

利用计算机技术对实验测定的铋离子示差脉冲极谱数据进行了如下处理:1)用修正的Gaossian方程拟合实验测定的极谱曲线,得到精确至±0.05mV的极谱峰电位;2)用极谱数据计算机分析系统CFC-Ⅱ计算因Bi(OH)~(2+)络合物的形成而造成的极谱峰电位移动值;3)对校正过的金属离子极谱峰电位值进行多项式曲线拟合,得到整个pH区间铋离子(Bi~(3+))的示差极谱峰电位值。数据处理与分析结果表明:当溶液的pH<2.5时,可以利用关系式E_p(mV)=-0.252[pH]~4+5.8748[pH]~3-37.673[pH]~2+94.303[pH]+19.1计算科离子的极谱峰电位(相对于银/氯化银参比电极);当溶液的pH值在2.5以上时,铋离子的极谱峰电位为101.13mV     

同位素源激发X荧光分析微量元素的实验研究

本文所介绍的实验工作主要有三部分。首先是实验条件的选择;其次是用AXIL软件包进行X射线能谱分析;第三部分是标准曲线及其修正,即如何确定内标法中的相对灵敏度因子。     

Creativity and simplicity

For many scientists, human intelligence and, in particular, its creative potential seem to consist of processes that cannot be automated by means of a computer. As already shown with fractal geometry, this short note tries to show that the iteration and combination of very elementary operations can give very complex behaviors and shapes. It gives some practical examples to encourage reader involvement and new experiments, particularly in classroom settings.     

用C语言实现的多道分析器软件系统

用Ｃ语言实现的多道分析器软件具有程序结构模块化等特点，因而有广泛的应用前景。