基于照度补偿的人脸图像遮挡阴影消除处理*

为了消除人脸图像中的遮挡阴影对识别精度的影响,采用数学形态学处理对阴影进行检测分离,根据其照度损失不同划分为阴影边缘区和阴影主体区,分别实施照度补偿,并将非阴影区、阴影边缘区和阴影主体区光强光顺过渡,实现对图像阴影区域的恢复处理。基于该照度补偿原理处理实例表明,该方法可以较好地去除人脸图像中部因遮挡造成的阴影,显著改善图像质量。     

Preparation of alginate/poly(N‐isopropylacrylamide) semi‐interpenetrating and fully interpenetrating polymer network hydrogels with γ‐ray irradiation and their swelling behaviors

Semi‐interpenetrating polymer network (semi‐IPN) and fully interpenetrating polymer network (full‐IPN) hydrogels composed of alginate and poly(N‐isopropylacrylamide) were prepared with γ‐ray irradiation. The semi‐IPN hydrogels were prepared through the irradiation of a mixed solution composed of alginate and N‐isopropylacrylamide (NIPAAm) monomer to simultaneously achieve the polymerization and self‐crosslinking of NIPAAm. The full‐IPN hydrogels were formed through the immersion of the semi‐IPN film in a calcium‐ion solution. The results for the swelling and deswelling behaviors showed that the swelling ratio of semi‐IPN hydrogels was higher than that of full‐IPN hydrogels. A semi‐IPN hydrogel containing more alginate exhibited relatively rapid swelling and deswelling rates, whereas a full‐IPN hydrogel showed an adverse tendency. All the hydrogels with NIPAAm exhibited a change in the swelling ratio around 30–40°C, and full‐IPN hydrogels showed more sensitive and reversible behavior than semi‐IPN hydrogels under a stepwise stimulus. In addition, the swelling ratio of the hydrogels continuously increased with the pH values, and the swelling processes were proven to be repeatable with pH changes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4439–4446, 2006     

电子商务配送速度与客户退单的关联建模仿真

在电子商务中,产品的配送速度与客户的退单率之间存在着较为复杂的关联性,这种关联性受到所在地域、购买时间、运输能力、订单处理能力、人为因素等多方因素的影响十分复杂.传统的建模方法只能利用多个简单的线性关系进行描述,加入了更多的复杂约束过程的描述,模型复杂,无法准确反映两者关系.为解决上述问题,提出基于PLS_SEM算法的电子商务中产品的配送速度与客户退单的关系建模方法.根据PLS_SEM算法的构建复杂模型特有的优势,建立电子商务客户退单评价模型,并利用退单校验因子定量分析了电子商务中不同的变量对于客户退单的影响,可以较好地解决模型中存在的过多约束问题,保证建模准确性.仿真结果表明,利用PLS_SEM算法能够实现对电子商务中产品配送速度与客户退单的关系进行准确分析,效果令人满意.     

Development of density distributions in injection molded amorphous engineering plastics. Part I

The gapwise density distributions of the injection molded specimens of two engineering thermoplastics, i.e., poly(phenylene ether) and poly(ether imide), were characterized employing the density gradient column technique. The samples were molded using a 40t Van Dorn injection molding machine. The effects of the thermal history on the density distribution of unconstrained quenched specimens were also investigated. In addition, various material properties, such as pressure-volume-temperature, isothermal contraction, and pressure induced densification behavior were characterized, for the two resins employed in this study. The moldings of the two resins exhibited different trends in their density distributions. These findings were explained in terms of the competing effects of cooling rate and the pressure history experienced by the engineering plastic resins during the molding cycle. The data collected were also used as input to mathematical modeling of density distributions in injection molded articles, which is reported in Part II of this article.     

基于半监督深度学习法的网络大数据集成挖掘

传统的数据集成挖掘方法在集成与挖掘两个步骤之间存在较大误差,导致大数据出现乱码问题,数据显示不全.为解决上述问题,提出基于半监督深度学习法的大数据集成挖掘方法.利用有监督与无监督深度学习间的机器学习,组成半监督深度学习.利用支持向量数据组建立超球体.依据超球体结合标记样本,组建半监督深度学习数据检测模型,筛选样本特征词,利用半监督深度学习方法训练单分类SVDD模型,实现网络大数据集成挖掘.仿真结果证明,所提方法能够高精度、高效的对大数据完成集成挖掘,具有理想的应用性能.     

基于python远程主机监控软件的设计与实现

针对网络运维工作中由于服务器主机空间分散导致值勤效率不高的问题,设计了一款可监控远程服务器运行信息的软件.软件基于python的psutil和wmi模块采集远程主机的运行信息,基于UDP套接字传送相关信息,基于SQLite数据库存储信息和Tkinter标准库设计了,运行信息在GUI进行展示.对软件进行实际环境部署并测试,运维人员可在监控端直接查看多台服务器的各类关键信息及运行状态.     

Fixed‐time synchronization for complex‐valued BAM neural networks with time delays

In this paper, the fixed‐time synchronization for complex‐valued bidirectional associative memory (BAM) neural networks with time delays is studied. Based on the fixed‐time stability, the Lyapunov functional method and some inequality techniques, a new criterion is presented to guarantee that the addressed systems achieve synchronization in fixed time and a more accurate estimation independent of the initial conditions is given for the settling time. Meanwhile, a new nonlinear delayed controller different from the existing ones is designed. In the end, two numerical examples are provided to illustrate the effectiveness of the obtained result.     

Global Avalanche Characteristics of Boolean Functions by Concatenation

In order to measure the correlation propeties of two Boolean functions,the global avalanche characteristics of Boolean functions constructed by concatenation are discussed,i.e.,f_1‖f_2and f_1‖f_2‖f_3‖f_4.Firstly,for the function f = f_1‖f_2,the cross-correlation function of f_1,f_2 in the special condition are studied.In this case,f,f_1,f_2 must be in desired form.By computing their sum-of-squares indicators,the crosscorrelation function between f_1,f_2 is obtained.Secondly,for the function g = f_1‖f_2‖f_3‖f_4,by analyzing the relation among their auto-correlation functions,their sum-of-squares indicators are investigated.Based on them,the sum-of-squares indicators of functions obtained by Canteaut et al.are investigated.The results show that the correlation property of g is good when the correlation properties of Boolean functions f_1,f_2,f_3,f_4 are good.     

遥感蒸散发数据应用对SWAT模型径流和蒸散发模拟精度的影响

为探讨遥感蒸散发数据补充研究区水文资料的能力,及其在SWAT模型应用中对径流和蒸散发模拟精度的影响。以淮河上游息县控制流域为研究区建模,并利用实测径流资料与遥感蒸散发数据(MOD16A2)设置3种参数率定情景:仅实测径流率定参数(S1)、仅遥感蒸散发率定参数(S2)、径流与蒸散发同时率定参数(S3),分析不同情景下径流与蒸散发过程的模拟效果。结果表明:从径流模拟而言,S2、S3较S1的模拟精度(NS系数)均有不同程度的降低,但S3在S2的基础上有较明显的改善;从子流域尺度上的蒸散发模拟而言,S1至S3模拟精度呈现出逐渐上升的趋势,在采用径流与蒸散发同时率定时,S3比S2情景NS系数上升的子流域个数占总数的46%。通过逐步深入探究遥感蒸散发数据在SWAT模型中的应用,以及对参数率定的影响,从而分析其对径流与蒸散发的模拟精度产生的变化,此方法也可推广到其他水文模型,在区域尺度水资源管理与利用上具有较好的参考价值。     

N-Fe共掺杂BiVO_4的制备及其光催化活性的研究

采用溶胶凝胶法制备了N和Fe共掺杂的Bi VO4可见光光催化剂,并用X射线衍射(XRD)、比表面积测试(BET)和紫外-可见漫反射谱(UV-Vis DRS)对其进行了表征.结果显示,N-Fe共掺杂对Bi VO4晶型没有产生影响,掺杂前后均为单斜晶系,但晶粒粒径有所减小,BET比表面积相对增大.由UV-Vis可知,N-Fe共掺杂的Bi VO4的吸光强度明显增强,禁带宽度变窄.以可见光降解甲基橙(MO)考察催化剂的光催化活性,N-Fe共掺杂的Bi VO4对MO的降解速率明显高于纯Bi VO4,证明N-Fe共掺杂产生的协同效应提高了Bi VO4在可见光照射下的光催化活性.