基于小波系数Hu矩的生物组织损伤监测方法

提出了一种基于B超图像的小波系数Hu矩特征值并结合支持向量机监测生物组织损伤的方法。利用高强度聚焦超声(HIFU)对新鲜离体猪肉组织进行辐照,实时获取辐照前后的B超图像,并对其进行预处理获取减影图像。提取减影图像的Hu矩、小波系数均值和基于小波系数的Hu矩3个特征值,分别利用支持向量机对生物组织样本进行学习、分类处理。结果表明:小波系数Hu矩特征值比Hu矩和小波系数均值的总辨识率分别高出2.70%和2.05%,从而可以更有效地监测HIFU治疗中生物组织损伤情况。该方法可以帮助临床医生客观地监控HIFU治疗过程,对提高HIFU疗效有实际意义。     

对称密钥加密算法在IPsec协议中的应用

IPsec协议是互联网中最重要的协议之一,也是多年来用以解决网络安全问题的技术,在路由器、防火墙等设备中有着广泛的应用,同时在各种软件系统中也扮演重要角色。通过对IPsec协议中加密算法的讨论,重点分析了对称密钥加密算法在ESP中的应用,包括DES、3DES、IDEA、AES、SM4等加密算法。分析了各个算法实现的特点、复杂度和安全强度,对比了算法在软硬件平台实现所需资源以及实现速度,为IPsec协议设计应用时提出了建议,能有针对性的使用对称密钥加密算法,合理有效的解决安全方案。     

基于不变矩和SVM的圆形交通标志识别方法研究

针对道路交通标志的自动识别问题,通过不变矩和支持向量机(SVM)方法对圆形标志图像识别方法进行研究。首先根据交通标志的颜色和形状信息对采集到的原始图像进行颜色分割、形态学去噪和形状检测等处理,获得图像中包含交通标志的区域。然后分别对标志图像进行Hu矩和Zernike矩的特征值提取,将特征值输入SVM中进行训练并采用网格搜索法对SVM进行参数优化,最后使用优化后的支持向量机方法实现交通标志的识别。实验表明,与现有的其他交通标志识别算法相比,采用高阶Zernike矩与优化后SVM的识别方法有更好的识别效果。     

Application of chemical composition and infusion colour difference analysis to quality estimation of jasmine-scented tea

Infusion chemical composition, colour difference indicators and volatile constituents of seventeen jasmine‐scented tea samples and their correlation with sensory total quality score given by tea‐tasting panel were studied by techniques of HPLC, colour difference metre and gas chromatograph. Spearman's linear correlation analysis showed that concentration of nitrogen, caffeine, catechin, epicatechin, catechin gallate, total catechins, terpineol, nerol and infusion light‐black indicator ΔL, yellow‐blue indicator Δb, total colour difference indicator ΔE were significantly correlated with sensory total quality score, respectively. Regression of the total quality score upon twelve components extracted from thirty‐six tested indicators by principal component analysis could properly estimate total quality score of two jasmine‐scented tea samples which were not included in the seventeen samples used to construct the regression model.     

Camellia加密算法基于硬件实现的优化

分别从整体和局部的角度,提出Camellia算法几种基于硬件编程实现的优化方法.在整体角度,以轮循环和模块复用方式实现紧凑型结构,而以流水线方式实现高速型结构;在局部角度,提出以树形化和共享子表达式的方法减小P置换电路时延、在F函数中只实现4个S盒,达到提高处理速度、节省硬件资源的目的.     

Preparation of tea catechins using polyamide

An adsorption separation method using Polyamide-6 (PA) as an adsorbent was developed to separate catechins from green tea extract. The adsorption capacity of total catechins for PA was 193.128 mg g⁻¹ with an adsorption selectivity coefficient K_A^B of total catechins over caffeine 21.717, which was better than macroporous resin model HPD 600. The Langmuir model and the pseudo-second order mode were primely fitted to describe its equilibrium data and adsorption kinetics, respectively. PA column separation by two-step elution using water and 80% (v/v) aqueous ethanol was established to prepare catechins complex which contained 670.808 mg g⁻¹ total catechins and 1.828 mg g⁻¹ caffeine. It is considered that PA was a promising adsorbent for selective isolation of catechins.     

基于视频的施工升降机乘客头部识别方法研究

针对目前人数统计检测主要以人工为主,存在人为因素干扰的问题,提出一种基于视频处理的升降机内人数统计方法,本文主要对系统中头部识别方面进行了研究,利用模板匹配算法寻找视频帧中与模板相近的人头位置,针对出现的两种虚警误判,分别采用运动区域检测和Hu不变矩形状匹配进行去除。实验结果表明,利用该方法能够有效的去除虚警,符合实际应用需求。     

基于最小外接圆补偿机制的形状图像检索

提出了一种新的基于最小外接圆补偿机制的二值形状图像检索算法,其不仅提取了目标区域的特征,而且补偿了目标最小外接圆下的背景区域特征。提取常用于描述区域特征的Hu不变矩和Zernike不变矩作为图像特征,不变矩特征具有平移、缩放、旋转不变性。图像相似度用归一化特征向量的欧氏距离表示。该方法不仅计算简单,而且可有效补偿人眼的视觉感受。通过大量实验表明,该算法较仅基于目标区域的检索算法取得了更好的检索精度和回召率。     

Essential oil composition of commercial black tea (Camellia sinensis)

The essential oil components of different tea brands were investigated by gas chromatography. The oil yields of dried tea samples were ranged from 0.09% to 0.63%. Twenty-five compounds from Supreme and Lipton Yellow Label tea brands representing 98.0% and 88.0% of the Camellia sinensis oil were identified, respectively. The main ones were β-pinene (51.2%) and α-pinene (30.2%). Nineteen components from Tapal tea brand representing 76.7% of the C. sinensis oil were determined with high contents of muurol-5-en-4-a-ol (10.5%) and muurol-5-en-4-b-ol (31.3%). Fifteen components from Deer and Diana tea brands were identified, accounting for 83.3% and 78.2% of the oil containing α-cadinol and β-pinene. Seventeen components from non-branded teas were determined with high contents of muurol-5-en-4-a-ol and muurol-5-en-4-b-ol. Twenty-one compounds from non-branded Bangladeshi Shezan and Indian teas were also identified. All oils consisted of monoterpenic hydrocarbons, oxygenated monoterpenes and sesquiterpenes.     

光杆落物打捞器的研制与应用

光杆落物打捞器是一种新型打捞工具，主要用于打捞重量较轻的细长光杆式井下落物（如测斜仪器，测井仪器等），详细介绍了该工具的结构，工作原理及使用注意事项，在两口井的成功应用表明，该工具能有效地捞获井下落鱼，具有很好的经济效益和社会效益。