Instabilities of Regression Estimates Relating Air Pollution to Mortality

The instability of ordinary least squares estimates of linear regression coefficients is demonstrated for mortality rates regressed around various socioeconomic, weather and pollution variables. A ridge regression technique presented by Hoer1 and Kennard (Technometrics 12 (1970) 69–82) is employed to arrive at “stable” regression coefficients which, in some instances, differ considerably from the ordinary least squares estimates. In addition, two methods of variable elimination are compared—one based on total squared error and the other on a ridge trace analysis.     

长春岭背斜带油气富集规律及有利区预测

在综合精细构造、储层、成藏系统研究基础上,进行空间上构造和砂体的匹配关系、油水追踪分析等综合研究,进而理清油气水分布规律,建立不同类型圈闭控油(气)与成藏模式.以解释复杂油气水分布现象,并为该类油藏的预测有利含油区.     

重型液压设备承载结构连接形式

在回顾预应力钢丝缠绕液压机的发展和现状的基础上,抽象出液压机的基本力学模型,指出重型设备工程领域常用的三种连接结构形式,即冶金结合结构、键合结构和坎合结构。分别从连接形式、力学特征和应用特性等多方面对其进行了全面比较分析,阐明了各种结合结构的优缺点,同时也阐明了坎合结构在重型承载中的应用优势。通过例举我国多台自主建造的万吨级重型压机实施情况,说明坎合原理及其技术在重型压机中已经得到广泛应用,在重型装备等行业中具有巨大潜在市场。     

腔体内壁脊形凹槽对微波反应器加热效率及均匀性的影响

提出在微波反应器腔体内壁设置脊形凹槽的优化策略,研究在保证加热效率的前提下提升微波加热的均匀性。利用有限元法仿真研究不同凹槽结构参数对微波反应器加热效率和均匀性的影响。研究结果表明:脊型凹槽结构能有效提升微波反应器的加热效率和加热均匀性。优化后微波反应器的加热效率达到98.75%,与微波腔壁光滑时相比,均匀性最大提升幅度达到58.54%。     

Ridge Polynomial神经网络带动量项异步梯度算法的收敛性

将动量项引入到Ridge Polynomial神经网络异步梯度训练算法的误差函数中,有效地改善了算法的收敛效率,并从理论上分析了Ridge Polynomial神经网络的带动量项的异步梯度算法的收敛性,给出了算法的单调性和收敛性(包括强收敛性和弱收敛性)。算法的这些收敛性质对于如何选取学习率和初始权值来进行高效的网络训练是非常重要的。最后通过计算机仿真实验验证了带动量项的异步梯度算法的高效性和理论分析的正确性。     

Fingerprint classification by a hierarchical classifier

Fingerprint classification is still a challenging problem due to large intra-class variability, small inter-class variability and the presence of noise. To deal with these difficulties, we propose a regularized orientation diffusion model for fingerprint orientation extraction and a hierarchical classifier for fingerprint classification in this paper. The proposed classification algorithm is composed of five cascading stages. The first stage rapidly distinguishes a majority of Arch by using complex filter responses. The second stage distinguishes a majority of Whorl by using core points and ridge line flow classifier. In the third stage, K-NN classifier finds the top two categories by using orientation field and complex filter responses. In the fourth stage, ridge line flow classifier is used to distinguish Loop from other classes except Whorl. SVM is adopted to make the final classification in the last stage. The regularized orientation diffusion model has been evaluated on a web-based automated evaluation system FVC-onGoing, and a promising result is obtained. The classification method has been evaluated on the NIST SD 4. It achieved a classification accuracy of 95.9% for five-class classification and 97.2% for four-class classification without rejection.     

利用响应面分析法优化鸟苷发酵培养基

目的利用响应面分析法对鸟苷发酵培养基进行优化,提高鸟苷产量。方法采用响应面分析法对鸟苷发酵培养基的3种主要成分葡萄糖、酵母粉和豆饼水解液进行优化。用Design-Expert软件对实验数据进行多元回归分析,并建立3种因素与鸟苷产量之间的函数关系。用最终优化的配方进行3次验证试验。结果通过岭脊分析,获得培养基中3因素最佳浓度为:葡萄糖12.0%,酵母粉1.4%,豆饼水解液4.0%,发酵液鸟苷最高产量可达28.3g/L。3次验证试验所测得的鸟苷产量分别为28.14、28.32和27.86g/L,平均值为28.10g/L,与预测结果基本一致。结论利用响应面分析法可优化鸟苷发酵培养基,显著提高鸟苷的产量。     

垄作冷渍型稻田氮、磷、钾化肥适宜施量及施用方法研究

通过垄畦栽冷渍型稻田早、中稻化肥不同施量及施用方法的田间试验,建立氮、磷、钾化肥施用量与产量的回归方程,推导出早、中稻氮、磷、钾化肥最佳施用量;在施肥量相等情况下,深施比表施肥效好,钾肥不足情况下,以稻草代钾肥同样取得较好增产效果。     

Thermal Characteriztion of 1.3 μm InAsP／InGaAsP Ridge Waveguide MQW Laser Based on Spectroscopy Method

An experimental way to analyze the thermal characteriztion of semiconductor lasers based on spectroscopy method under pulse driving conditions has been developed,By using this way the thermal characteristicss of strain compensated 1.3 μm InAsP/InGaAsP ridge waveguide MQW laser diodes have been investigated.Results shovw that by measuring and analyzing the lasing spectra under appropriate driving parameters and temperature ranges,the thermal resistance of the laser diodes could be deduced easily,A higer thermal resistance of 640 K/W has been measured on a narrow ridge laser chip without soldering.Other thermal and spectral properties of the laser have also been measured and discussed.