基于偏好矩阵遗传算法求解长期车辆合乘问题

针对长期车辆合乘问题（LTCPP）,提出带有偏好矩阵的遗传算法（PMGA）,将拥有私家车且目的地相同的用户群体分配到产生总花费最少的合乘小组。首先,建立计算基于全体用户费用成本的目标函数,构建以用户时间窗和车容量为约束的长期车辆合乘模型;然后,结合模型特点,在传统遗传算法（GA）的基础上,通过在交叉算子与变异算子中添加偏好矩阵记录并更新用户间的偏好信息来提高可行解的数量和质量。实验结果表明,在相同计算环境下,当用户数量小于200时,通过PMGA所获得的20个解中的最优解的值与最优化算法相同;而处理大规模的实例时,PMGA可以获得更高质量的解。所提算法可以明显提高长期车辆合乘问题的求解质量,在降低汽车尾气污染和减少交通拥挤等方面具有重要作用。     

An MILP-MINLP decomposition method for the global optimization of a source based model of the multiperiod blending problem

The multiperiod blending problem involves binary variables and bilinear terms, yielding a nonconvex MINLP. In this work we present two major contributions for the global solution of the problem. The first one is an alternative formulation of the problem. This formulation makes use of redundant constraints that improve the MILP relaxation of the MINLP. The second contribution is an algorithm that decomposes the MINLP model into two levels. The first level, or master problem, is an MILP relaxation of the original MINLP. The second level, or subproblem, is a smaller MINLP in which some of the binary variables of the original problem are fixed. The results show that the new formulation can be solved faster than alternative models, and that the decomposition method can solve the problems faster than state of the art general purpose solvers.     

A new statistical strategy for pooling: ELI

Doing exhaustive relevance judgments is one of the most challenging tasks in the construction process of an IR test collection, especially when the collection is composed of millions of documents. Pooling (or system pooling), which is basically a method for selecting documents to assess, is a solution to overcome this challenge. In this paper, to form such an assessment pool, a new, ranked-based document selection criterion, called the expected level of importance (ELI), is introduced. The results of the experiments performed, using TREC 5, 6, 7, and 8 data, showed that by using a pool in which the documents are sorted in the decreasing order of their calculated ELI scores, relevance judgments can efficiently be made by minimal human effort, while maintaining the size and the effectiveness of the resulting test collection. The criterion we propose can directly be adapted to the traditional TREC pooling practice in favor of efficiency, with no additional cost.     

浅析可信服务器池体系下的服务器冗余

现如今具有重要性能的互联网应用数量正在稳步增加。为了支持这类应用的发展和可操作性,IETF对经常参照的服务器冗余及交互过程故障转移体系定义了新的标准—可信服务器池(RSerPool)。可信服务器池体系的基本观点并不是全新的,但是它们与单一、节约资源型统一架构的结合是一个新的概念。通过服务器冗余获取服务有效性直接导致的负载分配以及平衡问题。对于可信服务器池系统的运行十分重要。因此,评估这类与服务应用要求的负载平衡策略相关的系统运行很重要。在这篇文章中,我们将对可信服务器池体系结构进行概述。我们也将简短介绍基本的SCTP协议规定以及它的链路冗余特征。这些都与重要的自适应和非自适应负载平衡策略有关。     

Mechanisms of superficial micropunctate corneal staining with sodium fluorescein: The contribution of pooling

Purpose

To establish if sodium fluorescein (SFL) dye accumulation within intercellular spaces on the ocular surface contributes to the appearance of superficial punctate corneal staining.

Methods

Thirteen subjects bilaterally wore PureVision™ lenses that had been pre-soaked in ReNu MultiPlus^® multipurpose solution. After 1 h of lens wear, corneal staining with SFL was assessed using a standard slit-lamp technique. Participants who presented with bilateral, corneal staining were selected for further evaluation. A randomly selected eye was rinsed with saline three times. Fellow eyes (control) received no rinsing. After each rinse, the appearance of SFL staining was recorded without any further instillation of the dye. To eliminate any confounding effects of staining due to residual fluorescein in the tear menisci, corneal staining was induced in freshly excised, isolated, rabbit eyes by topical administration of 0.001% PHMB and staining, rinsing and grading were performed as above.

Results

Nine out of 13 subjects presented with bilateral diffuse corneal staining (mean grade ± SD: 2.4 ± 0.7). The mean staining grades in test and control eyes respectively after each of the three rinses were (1) 2.41 ± 0.41, 2.25 ± 0.69 (p = 0.9); (2) 2.34 ± 0.79, 2.1 ± 0.83 (p = 0.8); and (3) 1.71 ± 0.65, 1.60 ± 0.79 (p = 0.6) there was no significant reduction in staining with rinsing (p > 0.05) and no difference was observed between test and control eyes at any sampling-point. Similar observations made in ex vivo rabbit eyes replicated these results.

Conclusions

Pooling or accumulation of SFL solution within intercellular spaces does not appear to contribute to the appearance of superficial micropunctate corneal staining.     

基于改进空间金字塔池化卷积神经网络的交通标志识别

针对雾天、光照、遮挡和大倾角等因素导致的交通标志识别准确率低、泛化性差等问题，提出一种基于神经网络的轻量级交通标志识别方法。首先，利用图像归一化、仿射变换和限制对比度自适应直方图均衡化（CLAHE）方法进行图像预处理，以提高图像质量；其次，基于卷积神经网络（CNN），融合空间金字塔结构和批量归一化（BN）方法构建改进空间金字塔池化卷积神经网络（SPPN-CNN）模型，并利用Softmax分类器实现交通标志分类；最后，选用德国交通标志识别数据集（GTSRB），对比不同图像预处理方法、模型参数和模型结构的训练效果，并验证和测试所提模型。实验结果表明，SPPN-CNN模型的识别精度达到98.04%，损失小于0.1，在低配GPU条件下识别速率大于3 000 frame/s，验证了模型精度高、泛化性强、实时性好的特点。     

ADO.NET性能的优化

本文主要分析了ADO.NET中两种典型的数据访问模式的性能,以及有肋于提高数据访问性能的存储结构和连接池技术,并进一步研究了ADO.NET中其他优化数据访问性能的方法。     

基于深度特征学习的复杂环境下陌生人脸匹配算法研究

复杂环境下的陌生人脸匹配,即在人脸存在光照、姿态干扰时,判断两张在训练集中从未出现过的人脸照片是否代表同一个人。在预处理阶段,采用多尺度视皮层算法,降低光照的影响,提出并采用基于PCA-SIFT特征的图片融合算法无监督地对齐人脸,降低人脸姿态的影响。在识别阶段,提出并采用半随机池化方法优化了局部卷积限制波尔兹曼机网络的稳定性,习得深度特征后采用基于信息熵的度量学习算法计算马氏距离并通过SVM分类识别。实验结果显示,提出的方法在LFW数据集上取得了78%的识别率,相比于采用相同训练模式的经典度量学习方法取得了7%的提高,验证了所提方法的有效性。     

论权益联营法与购买法在我国的应用

权益联营法和购买法是处理合并会计的2种方法，分别对应着企业购买合并和联合合并。目前，国外合并会计偏向于购买法，我国合并会计规定的处理方法也基本上偏向于购买法，但是在我国证券市场、资产评估市场不成熟和股本结构特殊的情况下，权益联营法仍然有适用范围。     

基于双通道卷积神经网络的文本情感分类算法

针对现有深度学习方法在文本情感分类任务中特征提取能力方面的不足,提出基于扩展特征和动态池化的双通道卷积神经网络的文本情感分类算法.首先,结合情感词、词性、程度副词、否定词和标点符号等多种影响文本情感倾向的词语特征,形成一个扩展文本特征.然后,把词向量特征与扩展文本特征分别作为卷积神经网络的两个输入通道,采用动态k-max池化策略,提升模型提取特征的能力.在多个标准英文数据集上的文本情感分类实验表明,文中算法的分类性能不仅高于单通道卷积神经网络算法,而且相比一些代表性算法也具有一定的优势.