广义锥函数类的变度量法

本文针对广义锥函数类模型建立的算法,把n维空间的极小化问题,转化为m维空间的极小化问题。同时,建立了基于广义锥函数模型求解一般无约束问题的算法。

非线性规划弱增广 Lagrange 函数变度量法

对一般的非线性规划问题给出了弱增广的Ｌａｇｒａｎｇｅ函数，利用变度量法求得下降方向，从而将原问题转化为一维极小化问题，再通过一维搜索求得问题的解，并证明了此方法的收敛性．

利用交替变度量法搜索边坡临界滑动面

在边坡工程中,如何准确、迅速地确定临界滑动面是治理边坡的关键问题。但传统极限平衡法存在准确性难以保证、搜索法工作量大和搜索中易陷入局部最小值陷阱等问题。提出了搜索边坡临界滑动面的交替变度量法,结合有限元强度折减法确定初始滑动面,采用均质典型算例进行分析,与常用的传统极限平衡法计算结果进行比较,验证了该方法的有效性和高效性。

前馈神经网络的二阶学习算法

前馈神经网络是神经网络中应用最广的一种．但由于神经网络采用Ｂ－Ｐ算法，收敛速度慢．在分析了神经网络算法原理的基础上，提出了一种基于变度量法的优化训练算法．仿真证明，这种算法能够大大提高神经网络的收敛速度．

无约束最优化图像重建算法研究

在无约束最优化为基础的图像重建问题中,为了提高迭代效率以及重建图像质量,首次提出将变度量法应用到图像重建中.分别给出了变度量法,最速下降法和共轭梯度法的算法描述,并且分析了这些方法的优缺点.变度量法在迭代效率和重建图像质量方面优于其它两种算法.通过模拟实验,分别对这三种算法进行了迭代次数和重建图像质量的比较,结果证明了变度量法的优越性.

两自由度系统的动力吸振器参数最优化设计

以附有动力吸振器的两自由度振动系统作为研究对象,利用达朗伯原理建立了数学模型,并进行无量纲化运算。针对动力吸振器的4个参数(κ,γ,δ,μ),综合运用变度量法中的Davidon-Fletcher-Powell(DFP)法、罚函数法、一维搜索法进行最优化设计,利用Matlab和Visual C++混合编程实现计算。计算结果表明:4个参数的收敛情况各有不同,γ和δ都趋于定义域的上限,而μ和κ则趋于一个定值。该结论对于在实际应用中合理设计动力吸振器的的参数、最大限度地抑制相关振动具有重要意义。

基于非线性规划的人体上肢运动研究

该文对非线性规划技术在人体上肢运动中的应用进行了研究,对解逆运动学问题的几种数值方法进行了分析和比较。然后根据这些方法的比较结果,该文选用了BFGS变度量法来求解与逆运动学问题等价的最小化问题,这种方法有良好的数值稳定性且对奇异矩阵不敏感,计算代价不高,程序设计也比较简单。最后,针对上肢的小范围运动设计了仿真系统,并和其他几种解逆运动学问题的方法在计算时间上进行了比较,结果表明了该方法的有效性和可行性。

Improving IAC Algorithm Based on Range Rate Measurement

Aim Interactive multiple model(IMM) algorithm was introduced into two? stage estimation to improve the estimating accuracy for system position and velocity.Methods The state estimation was carried out in mixed coordinates according to the nonlinear measure equation, a generalized interactive acceleration compensation(IAC) algorithm in mixed coordinate was presented. Results Simulation result shows the estimation accuracy is improved through changing measure equation in polar coordinates. Conclusion The estimation accuracy for position and velocity estimation, has been improved greatly, and the proposed algorithm has the advantage of less calculating time comparing with other multiple model methods.

GA-DFP分级优化技术的研究

本文提出了一种把遗传算法（GA）和交度量法（DFP）相结合的分级代化方法．即先以遗传算法进行优化，将其计算结果作为第二级变度量法的初始值．再进行优化计算。结果表明，该方法是一种提高代化质量的有效方法，既具备良好的全局收敛特性，又有较快的收敛速度和较高的优化精度。本文还通过举例说明了该方法的应用。

Slope analysis based on local strength reduction method and variable-modulus elasto-plastic model

Employing an ideal elasto-plastic model,the typically used strength reduction method reduced the strength of all soil elements of a slope.Therefore,this method was called the global strength reduction method(GSRM).However,the deformation field obtained by GSRM could not reflect the real deformation of a slope when the slope became unstable.For most slopes,failure occurs once the strength of some regional soil is sufficiently weakened; thus,the local strength reduction method(LSRM)was proposed to analyze slope stability.In contrast with GSRM,LSRM only reduces the strength of local soil,while the strength of other soil remains unchanged.Therefore,deformation by LSRM is more reasonable than that by GSRM.In addition,the accuracy of the slope's deformation depends on the constitutive model to a large degree,and the variable-modulus elasto-plastic model was thus adopted.This constitutive model was an improvement of the Duncan–Chang model,which modified soil's deformation modulus according to stress level,and it thus better reflected the plastic feature of soil.Most importantly,the parameters of the variable-modulus elasto-plastic model could be determined through in-situ tests,and parameters determination by plate loading test and pressuremeter test were introduced.Therefore,it is easy to put this model into practice.Finally,LSRM and the variable-modulus elasto-plastic model were used to analyze Egongdai ancient landslide.Safety factor,deformation field,and optimal reinforcement measures for Egongdai ancient landslide were obtained based on the proposed method.

Magnetization of GaAs Parabolic Quantum Dot by Variation Method

The magnetization of two interacting electrons confined in a quantum dot presented in a magnetic field had been calculated by solving the relative Hamiltonian using variational method. We had investigated the dependence of the magnetization on temperature, magnetic field strength and confining frequency. The singlet-triplet transitions in the ground state of the quantum dot spectra and the corresponding jumps in the magnetization curves had been shown. The comparisons show that our results are in very good agreement with reported works.

Non-isothermal curing kinetics and thermal properties of benzoxazine-phenolic copolymers

Using novolac phenolic resin, aniline and formaldehyde as raw materials, benzoxazine-phenolic copolymers with different percentages of benzoxazine rings were prepared. FT-IR was adopted to characterize the molecular structure of the novolac-type phenolic resin and the benzoxazine-phenolic copolymer BP31. In order to understand the curing process of the copolymers, the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry （DSC）, and the catalytical effect of phenolic hydroxyl on the curing behavior of copolymers was investigated. To investigate the thermal properties of this resin, the thermal degradation behaviors of the cured samples were studied by thermal gravimetric （TG） method, and glass-transition temperatures （Tg） of the cured copolymers were also evaluated by DSC. The dynamic Ozawa method was adopted to determine the kinetic parameters of the curing process as well. The activation energy is 78.8 kJ/mol and the reaction rate constant is in the range from 40.0 to 5.2 （K/min）＂ according to reaction temperatures. The Ozawa exponent decreases from 2.4 to 0.7 with the increase of reaction temperature, and curing mechanism is expounded briefly according to the results. TG result shows that the highest char yield of copolymers is 50.3%. The highest Tg of copolymers is 489 K, which is much higher than that of pure benzoxazine resin.

Structure-Property Relations in xWO3-0.31P2O5-0.31B2O3-（0.38-x）Cs2O （0.01 ≤ x ≤0.28） Glasses by IR, UV and EPR Spectroscopic Studies

Glasses in the series of xWO3-0.31P2O5-0.31B2O3-（0.38-x）Cs2O （0.01 ≤ x ≤0.28） （G1-G4： x= 0.01, 0.1, 0.19, 0.28） were prepared by sol-gel method. Glassy phase in the samples were ascertained by powder X-ray diffraction pattern. Differential scanning calorimetry （DSC） traces of the samples show glass transition temperature Tg, in the range 247-253 ℃. IR spectra at 300 K of G1-G4 show the presence of [WO6], [WO4], [PO4]^3-, [PO3]^2-, [BO4]^＋, [BO3] units in the glass matrix. Observed electron paramagnetic resonance （EPR） lineshapes show two signals with very different intensities which are associated with W^5＋ （5d^1） and Mo^5＋ （4d^1） （impurity） paramagnetic sites. Signal with values ofg factors in the range 1.68 〈 g⊥ 〈 1.72 and 1.58 〈 gⅡ 〈 1.62 are due to W^5＋ ions present in axially distorted octahedral symmetry. The optical absorption spectra show that the W^5＋ ions have pyramidal coordination, involving a tungstyl ion WO^3＋ （C4v symmetry）. EPR and optical studies suggest the existence of blocks of octahedra linked by tungsten clusters.

Optimization for ASP flooding based on adaptive rationalized Haar function approximation

This paper presents an adaptive rationalized Haar function approximation method to obtain the optimal injection strategy for alkali-surfactant-polymer(ASP) flooding. In this process, the non-uniform control vector parameterization is introduced to convert original problem into a multistage optimization problem, in which a new normalized time variable is adopted on the combination of the subinterval length. Then the rationalized Haar function approximation method, in which an auxiliary function is introduced to dispose path constraints, is used to transform the multistage problem into a nonlinear programming. Furthermore, an adaptive strategy proposed on the basis of errors is adopted to regulate the order of Haar function vectors. Finally, the nonlinear programming for ASP flooding is solved by sequential quadratic programming. To illustrate the performance of proposed method,the experimental comparison method and control vector parameterization(CVP) method are introduced to optimize the original problem directly. By contrastive analysis of results, the accuracy and efficiency of proposed method are confirmed.

In-Plane Creep Buckling of Concrete-Filled Steel Tubular Arches

The creep-induced deformation of the arch rib of concrete-filled steel tubular （CFST） arches under a sustained load can increase the bending moment, which may lead to earlier stability failure called creep buckling. To investigate the influences of concrete creep on the buckling strength of arches, a theoretical analysis for the creep buckling of CFST circular arches under distributed radial load is performed. The simplified Arutyunyan-Maslov （AM） creep law is used to model the creep behavior of concrete core, and the creep integral operator is introduced. The analytical solutions of the time-dependent buckling strength under the sustained load are achieved and compared with the existing formula based on the age-adjusted effective modulus method （AEMM）. Then the solutions are used to determine the influences of the steel ratio and the first loading age on the creep buckling of CFST arches. The results show that the analytical solutions are of good accuracy and applicability. For CFST arches, the steel ratio and the first loading age have significant influences on creep buckling. An approximate log-linear relationship between the decreased degrees of the creep buckling strength and the first loading age is found. For the commonly used parameters, the maximum loss of the buckling strength induced bv concrete creen is close to 40%

A CLASS OF REVISED BROYDEN ALGORITHMS

In this paper, we discuss the convergence of the Broyden algorithms withrevised search direction. Under some inexact line searches, we prove that the algorithms areglobally convergent for continuously differentiable functions and the rate of convergence of thealgorithms is one-step superlinear and n-step second-order for uniformly convex objective functions.

Theoretical and experimental study of 2D conformability of stretchable electronics laminated onto skin

Smoothly attaching the stretchable epidermal electronic devices(EEDs) onto the skin surface is highly desired to improve the measurement accuracy of electrophysiological signal.The paper presents an analytical approach to study interfacial mechanics of the 2D planar EEDs on the checkerboard buckling patterns of human skin.Energy variation method is proposed to determine a criterion whether EEDs laminate conformally onto the skin surface under undeformed and stretched cases.EEDs with low bending stiffness(thin,soft devices/backing layer),smooth and soft skin,and strong adhesion promote conformal contact.Furthermore,the adhesion energy at the EED/skin interface is measured by the homemade peeling experiment platform with different substrate thicknesses and areal coverages.The upper limit of the areal coverage for EED conformal contact with the skin is proposed with given EED/skin properties.Conformability of EEDs are validated by experiments with different substrate thickness,areal coverage and external loadings.It provides a design guideline for EED to conformally contact with the skin surface for more accurate biological signal monitoring.