微细铣削毛刺形成研究

微细铣削是在广泛材料范围内制造精密三维微小零件的一种柔性的、经济的加工方法,微细铣削的主要问题之一是有毛刺产生,对微细铣削过程中毛刺的形成及其影响因素进行实验研究与分析,得到微细铣削过程中各因素对毛刺形成影响的一般规律,在此基础上,通过合理地选择切削参数以及刀具路径规划,达到减小毛刺的目的。     

一类针对图像放大中反问题的变分模

在解决图像放大中的反问题时,Chambolle变分模型需要大量的计算迭代。针对这种不足,该文提出一类新的基于Besov空间的变分模型来解决相应问题。利用Besov半范数与小波系数范数的等价性,新模型将所求解的变分问题完全转化为基于小波域的变分序列,其极小化过程证明这些序列的最优解都可以表示为基于小波域的正交投影。实验结果表明:新方法处理后的放大图像边缘轮廓清晰、光滑,有意义的细节特征得到保留,去噪效果令人满意。     

遗传算法在齿轮减速机优化设计中的应用

从理论上探讨了基因遗传算法 (GA)与传统约束优化设计方法相结合的可能性 ,并从中发现“基因遗传算法+惩罚函数法”非常适合求解复杂的非线性约束优化问题 ,且成功地采用了“基因遗传算法 +惩罚函数法”对一个通用的二级斜齿圆柱齿轮减速机的概率可靠性优化设计的数学模型进行求解 ,与传统的优化方法相比 ,得到了一个较为理想的全域最优解 ;同时该方法也改善了基因遗传算法的局限性     

放射性废物的最少化

本文介绍了放射性废物最少化的意义和措施,总结了核电厂实现废物最少化的方法和作用,介绍了法国和美国废物最少化的经验。     

基于结构风险最小化的加权偏最小二乘法

为了在偏最小二乘法(PLS)建模过程中实现结构风险最小化(SRM),提出基于结构风险最小化的加权偏最小二乘法(WPLS)。WPLS先提取训练样本中的主元,然后使用支持向量机(SVM)训练算法计算训练样本权值,最后计算原始论域中的回归模型。该算法保留了PLS能有效地提取对系统解释性最强的信息的优点,并通过样本权值提高模型的泛化能力,从而实现SRM准则,所建立的模型具有可解释性。仿真计算证明了模型的有效性。     

Efficient solution for a single pile under torsion

This paper presents a simple and more efficient solution mechanism for solving the linear response of a single pile with a circular cross section under torque in “n” multilayered soils. The pile-soil system is modeled by a series of independent springs distributed along the pile shaft with each spring representing an individual layer of soil. The properties of each soil layer are assumed constant with the allowance for variation from layer to layer. The method is based on the energy principles and variational approach initially proposed by Vallabhan and Mustafa (1996) for a single pile under a vertical load, developed by Guo and Lee (2001) for a single pile under a lateral load, and developed by Zhang (2010) and Misra et al. (2013) for a pile under torque. With the proposed iterative solution scheme, the equivalent stiffness of a soil-pile system of individual pile segments is calculated from the bottom element to the top element, while torque and the angles of twist are calculated from the top element to the bottom element of the pile without having to simultaneously solve a large number of equations. The solution provides: (1) the distribution of the angles of twist, (2) the distribution of torque along the pile and (3) the equivalent stiffness of the pile-soil system. A comparison of the results of the analysis using the proposed new solution mechanism with those of existing analytical solutions and a three-dimensional finite element analysis shows that the proposed method is much more efficient.     

基于在线双边拍卖的分层联邦学习激励机制

在分层联邦学习中,能量受限的移动设备参与模型训练会消耗自身资源.为了降低移动设备的能耗,文中在不超过分层联邦学习的最大容忍时间下,提出了移动设备能耗之和最小化问题.不同训练轮次的边缘服务器能够选择不同的移动设备,移动设备也能够为不同的边缘服务器并发训练模型,因此文中基于在线双边拍卖机制提出了ODAM-DS算法.基于最优...     

The Nelder-Mead Simplex Procedure for Function Minimization

The Nelder-Mead simplex method for function minimization is a “direct” method requiring no derivatives. The objective function is evaluated at the vertices of a simplex, and movement is away from the poorest value. The process is adaptive, causing the simplexes to be continually revised to best conform to the nature of the response surface. The generality of the method is illust'rated by using it. to solve six problems appearing in the May 1973 issue of Technometrics.     

Regression Modeling of Ozonation Process in Wastewater Treatment Plants for Reduction of Waste Activated Sludge

This research was based on the hypothesis that waste activated sludge (WAS) from municipal wastewater treatment plants can be reduced by ozonation of excess biosolids to induce cell lysis and by promoting utilization of intracellular products released by ozonation of biosolids in the aeration basins. In this research, mathematical modeling studies were performed in order to define process design and major components of ozonation. The main purpose of the model simulations was to evaluate the effect of operational parameters of the ozonation system (such as dosage and duration of ozonation) and to determine the amount of solids to be ozonated in order to achieve desired mass reductions in WAS. This modeling study focused on identification of design parameters and their suggested range of operation. The model presented in this study does not intend to detail and analyze the impact of the scientific variables in the ozonation mechanism, nor does it try to model the biosolids destruction mechanisms when ozonation is applied. The computer model simulations indicated that zero biosolids yield conditions can be achieved if more biosolids than was grown on the influent wastewater was processed through the ozonation system. The simulations suggested that zero biosolids yield conditions can be observed if 2.4 times as much biosolids as was grown on the influent wastewater was processed through the ozonation column, with a daily R of about 0.08 mg O₃/mg TSS-day. Furthermore, zero biosolids yield conditions can also be observed if only the amount of waste biosolids grown on the influent wastewater was processed through the ozonation column with a higher average daily R of 0.2 mg O₃/mg TSS-day.     

某反应堆研究基地放射性废物最小化措施

介绍了某反应堆研究基地放射性废物最小化措施,具体包括优化管理、减少源项、再利用和再循环、废物减容等,以及实践中取得的经验。