Nonstationary Gabor frames for

Recently, continuous‐time nonstationary Gabor (NSG) frames were introduced in adaptive signal analysis. They allow for efficient reconstruction with flexible sampling and varying window functions. In this paper, we focus on the existence and construction of NSG frames in the discrete‐time setting. We provide existence results for painless NSG frames and for NSG frames with fast decaying window functions. We also construct NSG frames with noncompactly supported window functions from a known painless NSG frame. Some examples are provided to illustrate the general theory.     

A HIV Infection Model with Periodic Multidrug Therapy

This paper investigates the effects of periodic drug treatment on a HIV infection model with two co-circulation populations of target cells. We first introduce the basic reproduction ratio for the model, and then show that the infection free equilibrium is globally asymptotically stable if R0 < 1, while the infection persists and there exists at least one positive periodic state when R0 > 1. Therefore, R0 serves as a threshold parameter for the infection. We then consider an optimization problem by shifting the phase of drug efficacy functions, which corresponds to change the dosage time of drugs in each time interval. It turns out that shifting the phase affect critically on the stability of the infection free steady state. Finally, exhaustive numerical simulations are carried out to support our theoretical analysis and explore the optimal phase shift.     

近红外特征光谱的羊肉TVB-N浓度预测模型

为提高生鲜羊肉储存期内（4,8和20 ℃环境）挥发性盐基氮（TVB-N）的近红外光谱（NIR）检测的稳定性和准确性,选取特征光谱和预测模型是关键步骤。以121个羊肉样品为实验对象,采集生鲜羊肉680~2 600 nm波段的近红外光谱。以多元散射校正（MSC）、标准正态变换（SNV）等散射校正方法,Savitzky-Golay卷积平滑（SGS）、移动平均平滑（MAS）等平滑处理方法,以及归一化（Normalization）、中心化（Centering）、标准化（Autoscaling）等尺度缩放方法分别预处理光谱数据后建立偏最小二乘法（PLS）预测模型。比较发现SGS处理的光谱建模效果最好。利用蒙特卡洛采样（MCS）法及马氏距离法（MD）消除了羊肉光谱的5个异常数据。运用光谱-理化值共生距离（SPXY）算法划分总样本的75%（87个）为校正集样本,剩余29个为验证集样本,利用竞争性自适应重加权法（CARS）、无信息变量消除法（UVE）、改进的无信息变量消除法（IUVE）和连续投影算法（SPA）提取特征光谱得到的波长个数分别为14,713,144和15。将全光谱和4种方法提取的特征波长作为输入变量建立预测模型,CARS提取的波长所建立模型的性能优于UVE、IUVE和SPA提取的波长所建立模型的性能,表明CARS方法可以有效简化输入变量并提高预测模型的性能。改进后得到的IUVE法相比于UVE法,筛选出的波长数更少且模型性能有所提升。以提取的特征波长建立PLS,支持向量机（SVM）和最小二乘支持向量机（LS-SVM）预测模型,SVM模型得到最优的校正集预测结果,其中CARS-SVM预测模型的校正决定系数（R2_C）和校正均方根误差（RMSEC）分别为0.939 1和1.426 7,最优的验证集预测效果为LS-SVM预测模型得到,其中IUVE-LS-SVM预测模型的验证决定系数（R2_V）和验证均方根误差（RMSEV）分别为0.856 8和1.886 2。基于近红外特征光谱建立简化、优化的生鲜羊肉储存期TVB-N预测模型,为实现快速无损检测生鲜羊肉中的TVB-N浓度提供技术支持。     

Modal Aggregation and the Theory of Paraconsistent Filters

This paper articulates the structure of a two species of weakly aggregative necessity in a common idiom, neighbourhood semantics, using the notion of a k-filter of propositions. A k-filter on a non-empty set I is a collection of subsets of I which (i) contains I, (ii) is closed under supersets on I, and (iii) contains ∪{X_i ≤ X_j : 0 ≤ i < j ≤ k} whenever it contains the subsets X₀,…, X_k. The mathematical content of the proof that weakly aggregative modal logic is complete relative to k-ary frame theory, the standard semantic idiom for weakly aggregative modal logic (see [1]) is presented in language-independent terms as a representation theorem for k-filters: every non-trivial k-filter is included in the union of ≤ k non-trivial filters. The elementary theory of k-filters is developed and then applied in the form of an ultrafilter extension result for k-ary frame theory. Mathematics Subject Classification: 03B45.     

A new identity for Parseval frames

In this paper we establish a surprising new identity for Parseval frames in a Hilbert space. Several variations of this result are given, including an extension to general frames. Finally, we discuss the derived results.

     

高能核－核作用中不同带电强子快度分布

在反应体质心系中，依据热化模型并考虑碰撞参量的涨落及核阻止性，对工作在ＢＮＬ／ＡＧＳ上Ｅ－８０２合作组给出的中心和周边Ｓｉ与Ａｕ、Ｃｕ和Ａｌ相互作用的强子快度分布进行了分析和讨论．     

抽样调查的设计与分析(Ⅰ)

本文讨论抽样调查实践中有关设计和数据分析的若干问题．第一部分主要涉及设计问题．     

帧转移型数字相机帧转移模糊的复原

帧转移型面阵CCD相机因其诸多优点而得到了广泛的使用 ,但它也存在帧转移模糊的问题。介绍了CCD相机的几种面阵类型及其各自的一些特点 ,重点介绍了帧转移型面阵器件的工作过程 ,分析了面阵CCD器件帧转移模糊形成的原因 ,并提出了解决帧转移模糊的方法。介绍了用该方法消除帧转移模糊的实例 ,验证了方法的有效性