关于换行逆修正法

给出了求解非线性方程组Ｆ（ｘ）＝０的一种不含求逆运算的换行法。该方法保护了Ｆ‘（ｘ）的稀疏性的传递性，避免了矩阵求道，具有适用范围广，计算量少等优点。     

灵敏电流计动力学特性的研究

通过对灵敏电流计线圈动力学方程的深入分析，提示了三种运动情形的物理内涵及进行《灵敏电流计》实验的理论根据，并澄清了一些模糊认识。     

一维波动方程反问题的一种迭代解法及其敛速估计

对地震勘探中的一维波动方程反问题，给出了一种迭代解法，并证明了该算法的收敛性。     

摆线齿轮加工节圆为任意值时滚刀齿形曲线的计算

本文以点齿代换法为媒介,从运动学和几何学出发,导出了摆线针轮减速器中摆线齿轮在任意加工节圆时,计算滚刀齿形曲线的通用方程式,此方法避免了现行啮合计算法中繁杂的微积分等数学运算,是一种较为简便的计算方法.     

A new generalized heterogeneous data model (GHDM) to jointly model mixed types of dependent variables

This paper formulates a generalized heterogeneous data model (GHDM) that jointly handles mixed types of dependent variables—including multiple nominal outcomes, multiple ordinal variables, and multiple count variables, as well as multiple continuous variables—by representing the covariance relationships among them through a reduced number of latent factors. Sufficiency conditions for identification of the GHDM parameters are presented. The maximum approximate composite marginal likelihood (MACML) method is proposed to estimate this jointly mixed model system. This estimation method provides computational time advantages since the dimensionality of integration in the likelihood function is independent of the number of latent factors. The study undertakes a simulation experiment within the virtual context of integrating residential location choice and travel behavior to evaluate the ability of the MACML approach to recover parameters. The simulation results show that the MACML approach effectively recovers underlying parameters, and also that ignoring the multi-dimensional nature of the relationship among mixed types of dependent variables can lead not only to inconsistent parameter estimation, but also have important implications for policy analysis.     

Design of Continuous and Discrete LQI Control Systems with Stable Inner Loops

Design approaches were proposed for both continuous and discrete LQI (linear quadratic with integral) controllers, if exist, to stabilize the inner loops in addition to stabilizing the closed loops and minimizing the quadratic cost functionals. Derived from the algebraic Riccati equations involved in continuous and discrete LQI control, the design approaches were straightforward obtained by setting the quadratic cost functionals to decoupled forms with positive definite weighting matrices. Examples were provided to verify the effectiveness of the approaches.     

准饱和土地基中瑞利波的传播特性

基于Biot两相饱和多孔介质理论,推导了准饱和土中瑞利波弥散特征方程,并研究了饱和度对准饱和土中瑞利波的弥散特性和位移分布的影响。结果表明,气相的存在对准饱和土中瑞利波速及弥散特性影响不大,但含气量变化对土骨架和流相的位移会产生很大的影响。     

天然气长输管道管存计算方法研究

目前,大多数管存计算公式采用稳态方法,精度较低。为精确计算管道管存,应精确计算存气管道气体温度、压力及压缩因子。文中将管段内气体由起点至终点参数动态变化看作一个多变指数为n的热力学参数变化过程,依据气体流动状态方程、运动方程推导出新的管存计算公式,计算过程采用分段计算累加的方法。经实例计算,与其他计算公式及TGNET软件模拟结果进行对比,推导公式计算精度较高。     

Excel中用Newton迭代法求解土的最优含水率和最大干密度的方法

在Excel中先根据试验数据自动生成击实曲线、趋势线拟合公式,然后用Newton迭代法求解高次方程,得出最优含水率和最大干密度.     

Method to calculate resistance of high-speed displacement ship taking the effect of dynamic sinkage and trim and fluid viscosity into account

A method is presented to calculate the resistance of a high-speed displacement ship taking the effect of sinkage and trim and viscosity of fluid into account. A free surface flow field is evaluated by solving Reynolds averaged Navier-Stokes (RANS) equations with volume of fluid (VoF) method. The sinkage and trim are computed by equating the vertical force and pitching moment to the hydrostatic restoring force and moment. The software Fluent, Maxsurf and MATLAB are used to implement this method. With dynamic mesh being used, the position of a ship is updated by the motion of ??ship plus boundary layer?? grid zone. The hull factors are introduced for fast calculating the running attitude of a ship. The method has been applied to the ship model INSEAN2340 for different Froude numbers and is found to be efficient for evaluating the flow field, resistance, sinkage and trim.