Kauffman代数的Gr?bner-Shirshov基（英文）

本文给出Kauffman代数的Gr?bner-Shirshov基,并且作为一个应用,还给出Kauffman代数的一组由Jones正规词组成的线性基.     

具有工作休假及休假中止的$M/M/1$排队模型的主算子的点谱

本文考虑具有工作休假及休假中止的$M/M/1$排队模型的主算子的点谱. 证明该模型主算子在左半轴有不可数无穷多个特征值. 此结果描述了主算子的点谱. 然后证明该主算子生成的$C_0$-半群的本质增长界为0,由此推出该$C_0$-半群不是紧算子、它的本质谱半径等于1. 此外,这些结果蕴含该模型的时间依赖解不可能指数收敛于其稳态解.     

基于空间自相关的城市化、经济与生态环境协调发展分析——以新疆巴州地区为例

以巴州地区9县市为研究对象,选取2002-2012年城市化、经济与环境相关评价指标,通过变异系数法,结合加权求和得到三系统综合得分,结合耦合协调度模型确定9县市的城市化、经济与环境子系统之间的协调度,对巴州地区各县市的协调发展状况进行空间自相关分析,研究三者的空间演化,结论如下:1)城市化、经济、环境三系统均呈现波动前进,巴州地区协调程度逐渐增强,呈现比较明显的上升态势;2)巴州9县市协调程度主要集中于中度协调和低度协调两个类型,表明三者之间的协调度还有很大的发展空间,有待进一步提高;3)城市化、经济与环境协调发展的空间自相关总体上呈正相关、相似性与集聚性向负相关、异质性的趋势发展;4)局部空间自相关的聚类分布发现和硕、博湖、尉犁位于高高区域,结合中心城市库尔勒市的行政地位及其地理位置等优势,发挥辐射带动作用,促进周边城市的发展.     

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In software defect prediction with a regression model, too many metrics extracted from static code and aggregated (sum, avg, max, min) from methods into classes can be candidate features, and the classical feature selection methods, such as AIC, BIC, should be processed at a given model. As a result, the selected feature sets are significantly different for various models without a reasonable interpretation. Maximal information coefficient (MIC) presented by Reshef et al.\ucite{4} is a novel method to measure the degree of the interdependence between two continuous variables, and an available computing method is also given based on the observations. This paper firstly use the MIC between defect counts and each feature to select features, and then conduct the power transformation on the selected features, and finally build up the principal component Poisson and negative binomial regression model. All experiments are conducted on KC1 data set in NASA repository on the level of class. The block-regularized $m\times 2$ cross-validated sequential $t$-test is employed to test the difference of performance of two models. The performance measures of a model in this paper are FPA, AAE, ARE. The experimental results show that 1) the aggregated features, such as sum, avg, max, are selected by MIC except min, which are significantly different from AIC, BIC; 2) the power transformation to the features can improve the performance for majority of models; 3) after PCA and factorial analysis, two clear factors are obtained in the model. One corresponds to the aggregated features via avg and max, and the other corresponds to the aggregated features with sum. Therefore, the model owns a reasonable interpretation. Conclusively, the aggregated features with sum, avg, max are significantly effective for software defect prediction, and the regression model based on the selected features by MIC has some advantages.     

连续小波变换的土壤有机质含量高光谱估测

土壤有机质含量的高光谱估测可快速、准确监测土壤肥力,对现代化农业生产进行精准施肥提供科学依据。以新疆渭干河-库车河三角洲绿洲耕层土壤为研究对象,对采集的98个土壤样品的原始光谱反射率R分别进行传统倒数对数lg(1/R)、一阶微分R′和倒数对数一阶微分[lg(1/R)]′数学变换,以及基于小波母函数Bior1.3不同尺度分解的连续小波变换（CWT）,并与实测土壤有机质含量进行相关分析,从而筛选出各类变换下与土壤有机质含量密切相关的特征波段和小波系数（p<0.01）。分别以原始光谱反射率（R）以及不同变换处理下的特征波段反射率和敏感小波系数作为自变量,土壤有机质含量作为因变量,采用偏最小二乘回归和支持向量机回归方法构建土壤有机质含量的估测模型。结果表明：（1）各类光谱变换方法有效提升光谱与土壤有机质含量之间的敏感性,其中经CWT变换后的土壤光谱反射率与有机质含量的相关性得到显著提高,相关系数由0.39提高到0.54（p<0.01）。（2）传统的[lg(1/R)]′变换构建的支持向量机回归模型,其决定系数（R2）高于lg(1/R)和R′变换构建的模型,说明倒数对数一阶微分变换可有助于提高估测模型的精度,且支持向量机回归模型的精度和稳定性高于偏最小二乘回归模型。（3）经过CWT分解后,以原始光谱反射率在不同尺度上的敏感小波系数作为自变量建立的模型,估测精度和稳定性均有明显的提高,构建的R-CWT-23-SVMR模型的决定系数（R2）为0.84,均方根误差（RMSE）为1.48,相对分析误差（RPD）等于2.11,模型精度达到最高并拥有极好的预测能力。高光谱数据经多种变换处理后可有效去除白噪声,而连续小波变换处理比传统的数学变换方法更适合于挖掘土壤有效信息,实现光谱信号的近似特征和细节特征的有效分离,建立的反演模型可更加精准估测土壤有机质含量。     

头部旋转运动下自适应非接触鲁棒性心率检测方法

基于人脸视频的生理信号检测面临的主要挑战是运动伪影噪声.针对受试者头部刚性旋转运动引起的伪影噪声,本文提出利用头部运动信息构建自适应滤波器的非接触式心率检测方法.该方法利用人脸二维和三维的特征点计算受试者运动中头部的偏航和俯仰欧拉角度,并将其作为调控过程噪声协方差的信号质量指数,进而构建了自适应Kalman滤波器,实现了稳健的心率估计.实验结果表明:本文提出的方法可有效抑制头部刚性旋转运动引起的噪声,平均绝对误差为2.22 beat/min,均方根误差为2.76 beat/min,与现有方法相比准确度分别提升9%与24.6%,具有统计显著性.本文提出的头部旋转角度自适应非接触鲁棒性心率检测方法在自发运动的真实场景下能有效提升检测的准确性,扩大了成像式光电容积描记技术在视频健康监测领域的使用场景.     

湍流大气中随机粗糙表面激光回波空间相干性仿真

根据广义Huygens-Fresnel原理,推导了von Karman湍流谱条件下激光回波复相干度的理论解析式;基于湍流相位屏分步传输算法和随机粗糙目标表面模型,实现了激光回波光场的仿真计算.首先通过镜面反射回波光场的仿真分析,验证了算法的正确性;然后基于1.1 km的均匀传输路径,综合分析了随机粗糙目标表面特性和路径湍流强度对回波光场复相干度的影响.结果表明:回波光场的空间相干性随目标表面高度均方根的增大而降低,随目标表面相关长度的减小而降低;当表面相关长度远小于大气相干长度时,回波相干性会被严重破坏.该研究可为目标表面特性或利用已知表面获取路径湍流状态的相干探测提供有益的参考.     

毛细管电泳前沿分析法及分子模拟辅助研究牛血清白蛋白与荧光素钠的相互作用

应用毛细管电泳前沿分析法研究了荧光素钠与牛血清白蛋白(BSA)之间的相互作用,利用游离荧光素钠平台峰高度和荧光素钠浓度与峰高的线性关系得出游离以及与BSA结合的荧光素钠浓度,将不同浓度比的荧光素钠-BSA相互作用体系进行电泳,考察结合情况,进一步采用非线性方程和线性方程对数据进行拟合处理,得到了荧光素钠和蛋白质在286...     

Homotopy analysis solutions for the asymmetric laminar flow in a porous channel with expanding or contracting walls

In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homotopy analysis method (HAM) is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail.     

Large eddy simulation of vertical turbulent jets under JONSWAP waves

The effect of random waves on vertical plane turbulent jets is studied numerically and the mechanism behind the interaction of the jet and waves is analyzed. The large eddy simulation method is used and the σ-coordinate system is adopted. Turbulence is modeled by a dynamic coherent eddy model. The σ-coordinate transformation is introduced to map the irregular physical domain with a wavy free surface and an uneven bottom onto a regular computational domain. The fractional step method is used to solve the fil...