纯中性事例事例顶点z坐标的最小二乘拟合

对于相互作用顶点z坐标未知的纯中性事例, 发展了一种运动学拟合的方法. 经蒙特卡罗样本检验, 拟合所用的程序是合理可靠的. 把该方法用于ψ′→γπ⁰→γγγ蒙特卡罗样本, 得到了更高的选择效率. 该方法可普遍应用于正负电子对撞实验中纯中性事例的分析.     

数据区对最小二乘法拟合函数系数偏差的影响

一、问题提出在许多问题的研究中需要对实验结果作出理论解释。提出理论模型,用最小二乘法进行测量数据拟合,以此来验证理论模型的正确性。在组合测量的数据处理过程中,同时给出各拟合参量(系数)的估计偏差。拟合结果有时是曲线与实验点符合很好,而有些参量的估计偏差却很大,怎样解释这些大偏差呢?     

D-u关系的最小绝对值线性拟合法

 采用最小绝对值方法对几类物质的冲击波速度D与波后粒子速度u的关系进行了直线拟合,并将其与常用的最小二乘法拟合的结果进行了比较。结果显示：对于实验数据分散性较小的密实材料（金属、离子晶体、氧化物等）,两种方法拟合的线性系数一致;而对于实验数据分散性较大的一些疏松材料（包括液体等）,两种方法拟合的线性系数有差异。对所有物质,最小绝对值法拟合的平均绝对误差比最小二乘法拟合的要小,因而最小绝对值法较最小二乘法有更高的准确性。同时讨论了导致这两种拟合差异的因素。     

Zernike多项式拟合干涉面方法研究

本文就专著和文献中关于Zernike多项式拟合干涉波面几乎都建设采用Gram-Schimdt正交化方法,而不采用比较简单的传统经典的最小二乘法问题进行了深入研究,从理论和实践上严格地证明了两种方法的等价性。实践中发现,用最小二乘法求解Zernike多项式拟合系数的速度比用Gram-Schimdt正交化方法提高了三倍之多。由于在精密光测技术中,Zernike多项式已被广泛采用,因此,“等价性”的证明具有重要意义,并对于其它类似问题也有着普遍的参考价值。     

北京谱仪顶点探测器触发效率的研究

模拟了北京谱仪(BESⅡ)顶点探测器的触发判选系统,发现对于某些带次级顶点的衰变道,其顶点探测器触发效率较低.并由此对BESⅡ中与效率相关的物理过程作了讨论,给相应的触发设计者提供参考.     

基于Matllab的约束最小二乘法拟合磁滞回线

由实验测得的磁滞回线数据的是一系列离散、带噪声的值。通过约束最小二乘方法对曲线进行分段拟合,使曲线的畸变程度得到了改善,准确地表达磁滞回线的特性,为磁材料的定量分析述提供了基础。     

LED可变光谱光源的多光谱拟合反演研究

利用多个不同光谱的LED单元成功拟合出几种特征明显的常见标准光源光谱。重点研究了如何通过目标光谱的特性反向找到所需要的LED的频带分布和最小使用的LED数目,进而利用所得结果对原有拟合模型进行条件判别和改进。对一些实测的目标光谱进行了模拟仿真,取得了较为理想的结果。     

最小二乘拟合计算有机薄膜晶体管迁移率的研究

本文通过制备了一个基于并五笨为有源层的顶栅底接触OTFT器件获取电流电压实验数据,并运用电流电压特性曲线理论拟合计算方法计算其场效应迁移率.研究发现,采用不同的拟合方法得到的场效应迁移率值有较大的差异.若选取转移特性曲线线性区距中心1/2范围内测试点进行最小二乘拟合计算出的场效应迁移率能减少采用其他拟合方法的固有不准确性,而且与其他方法得到的场效应迁移率最接近. 关键词： 最小二乘拟合 场效应迁移率 有机薄膜晶体管     

线性拟合中的逐差法和最小二乘法的比较

两变量间的线性关系y=A Bx是物理实验中常见的研究对象,本定量讨论用最小二乘法和逐差法进行线性拟合时,所求得的斜率的标准差的关系及因变量的误差对斜率误差的影响。     

Primary Vertex Fitting in BES

In this paper,the principle of primary vertex fitting of BES has been described. Some modifications to the original program are made and the vertex distributions for the experimental data of Run462—961 are presented.     

北京谱仪Ⅱ顶点探测器径迹重建软件的研究

解决了北京谱仪Ⅱ顶点探测器径迹重建软件系统——VCJULI从HP-Unix平台到PC-Linux平台移植中“字典存放”和精度处理的问题,从而使两平台上的候选径迹差别从74%降至0.02%;径迹参数中一些量的差别从5%下降至0.5%左右.大大改善了寻迹质量并节省了CPU时间     

Integrals of Vertex Operators and uantum Shuffles

Given a braided vector space , we show that iterated integrals of operator-valued functions satisfying a certain exchange relation give rise to representations of the quantum shuffle algebra built on . Using the quantum shuffle construction of the 'upper triangular part' of a quantum shuffle, this provides a simple proof of the result of Bouwknegt, MacCarthy and Pilch saying that integrals of vertex operators acting on certain Fock modules give rise to representations of .     

基于GoeGebra对简谐运动的振动图像进行拟合

借助GoeGebra软件对简谐运动的振动图像进行拟合,解决了中学物理教师难以根据振动图像(x-t图)利用拟合法获得振动规律的困境.     

Coupling Vertex of the Pomeron to Nucleon in QCD

The coupling vertex of the Pomeron to nucleon is derived from QCD. A γμ coupling vertex and coupling strength of β＝ 6.0 GeV-1, which has been used commonly as a free parameter in literature, are obtained. The result leads a support to the belief that the Pomeron could be a tensor glueball ξ(2230) with quantum numbers of IGJPC ＝ 0+2++ in nature.     

Three-Dimensional Vertex Model Related BCC Model in Statistical Mechanics

In this paper, a three-dimensional vertex model is obtained. It is a duality of the three-dimensional integrable lattice model with N states proposed by Boos, Mangazeev, Sergeev and Stroganov. The Boltzmann weight of the model is dependent on four spin variables, which are the linear combinations of the spins on the corner sites of the cube, and obeys the modified vertex-type tetrahedron equation. This vertex model can be regarded as a deformation of the one related to the three-dimensional Baxter-Bazhanov model. The constrained conditions of the spectrums are discussed in detail and the symmetry properties of weight functions of the vertex model are presented.     

Transverse Vector Vertex Function and Transverse Ward-Takahashi Relations in QED

The transverse vector vertex function in momentum space in four-dimensional QED is derived in terms of a set of transverse Ward-Takahashi relations for the vector and the axial-vector vertices in the case of massless fermion. It is demonstrated explicitly that the transverse vector vertex function derived this way to one-loop order leads to the same result as one obtained in perturbation theory. This provides a basic approach to determine the transverse part of basic vertex function from the symmetry relations of the system.     

Fermion-Boson Vertex at Finite Chemical Potential

Based on the Ward-Takahashi identity at finite chemical potential and Lorentz structure analyms, we generalize the Ball-Chiu vertex to the case of nonzero chemical potential and obtain the general form of the frmionboson vertex in QED at finite chemical potential.     

Transverse Vector Vertex Function and Transverse Ward-Takahashi Relations in QED

The transverse vector vertex function in momentum space in four-dimensional QED is derived in terms of a set of transverse Ward-Takahashi relations for the vector and the axial-vector vertices in the case of massless fermion.It is demonstrated explicitly that the transverse vector vertex function derived this way to one-loop order leads to the same result as one obtained in perturbation theory. This provides a basic approach to determine the transverse part of basic vertex function from the symmetry relations of the system.     

Quantum Kac– Algebras and Vertex Representations

We introduce an affinization of the quantum Kac–Moody algebra associated to a symmetric generalized Cartan matrix. Based on the affinization, we construct a representation of the quantum Kac–Moody algebra by vertex operators from bosonic fields. We also obtain a combinatorial indentity about Hall–Littlewood polynomials.