HSV色彩空间中的多阈值车牌定位分割方法

摘要: 本文是在 HSV颜色空间下, 根据车牌区域的颜色和几何特征, 通过多阈值分割的方法, 综合利用数学形态学运算、 连通域形状和字符密度检测, 有效解决了彩色图片车牌提取的问题。 实验表明, 该方法效果好, 精度高, 通过 154 幅实测机动车图象进行车牌定位分割, 准确率91%。福建省青年科技人才创新项目资金: "基于视频的运动体检测与控制技术" (2001J003

家兔右室流出道心肌细胞的L-型钙电流

特发性室速主要起源于右室流出道(rVOT),目前对于此类心律失常的发生机制还不清楚.已有临床报告指出,源于右室流出道的心律失常,可能是基于触发性机制.但迄今为止,由于技术上的困难,对rVOT心肌细胞的实验研究极少,尚无法证实所推测的机制.l-型钙电流(ICA-l)是主要的内向电流之一,在心律失常的发生中起重要作用.本实验通过对家兔右室流出道心肌细胞ICA-l特性的研究,探索特发性右室流出道室速的可能发生机制.采用全细胞膜片钳技术记录rVOT和右心室(rV)心肌细胞的动作电位(AP)及ICA-l,并对比分析两者AP及ICA-l的特性.结果发现,rVOT心肌细胞AP离散度较rV大(rVOT,577.2±364.8MS;rV,386.2±163.4MS).在rVOT存在APd明显缩短和明显延长的心肌细胞.用4-AP阻断瞬时外向钾电流(ITO)后,未记录到APd明显缩短的细胞;而APd明显延长的细胞仍存在.少数rVOT细胞AP具有很长的平台甚至复极无法恢复到静息电位.它们能自发产生早后除极(EAd),可以诱发出第二平台反应;在rV中未记录到这种细胞;这些APd明显延长的rVOT心肌细胞与rV心肌细胞相比具有较大的ICA-l(13.16±0.87PA/Pf,8.59±1.97PA/Pf,P<0.05);用尼非地平(10μMOl/l)阻断l-型钙通道后,ICA-l减小,动作电位时程缩短,rVOT心肌细胞记录到的长平台、EAd及第二平台反应消失.结果表明,rVOT心肌细胞APd离散度较rV心肌细胞大,是源于右室流出道的室速(rVOT-VT)的细胞电生理学基础.较大的ITO电流可能是导致rVOT心肌细胞APd明显缩短的原因之一;较强的ICA-l是导致rVOT动作电位明显延长的因素之一,并能出现EAd,这可能是rVOT产生触发性活动的机制之一

The properties of action potential and sodium-calcium exchange tail current of rabbit right ventricular outflow tract myocytes

目的研究兔右室流出道(rVOT)心肌细胞动作电位及钠钙交换尾电流(InCX,TAIl)相关特性,探讨源于rVOT室性心律失常的发生机制。方法采用全细胞膜片钳技术记录兔右室(rV)游离壁和rVOT心肌细胞的动作电位,在不更换细胞及电极内液情况下连续记录InCX,TAIl,对比分析两者动作电位和InCX,TAIl特性。结果兔rVOT心室肌细胞动作电位复极时程(APd)的变异程度大于rV游离壁心肌细胞。在rVOT心肌细胞记录到早期后除极及显著延长的APd。动作电位显著延长及后除极的rVOT心肌细胞所对应的InCX,TAIl到达峰值时程较动作电位正常的细胞延迟,并且电流强度大于rV游离壁对照组心肌细胞(P<0.05)。结论 rVOT心肌细胞APd变异程度大,而且APd显著延长的rVOT细胞InCX,TAIl到达峰值时程延迟及相应电流显著增大,这是rVOT部位好发触发活动的重要机制。Objective To explore the electrophysiological basis of arrhythmogenesis in right ventricular outflow tract(RVOT) myocytes of rabbit heart.The properties of action potential and sodium-calcium exchange tail current(INCX,tail) in rabbit RVOT cells were observed.Methods Patch-clamp technique was used to measure INCX,tail and action potential in single myocytes obtained by enzymatic dispersion of rabbit ventricle.Results Marked variability of action potential repolarization was observed in rabbit RVOT cardiomyocytes.The events of early afterdepolarization(EAD) and marked action potential duration(APD) extension were recorded in RVOT cells.The peak of INCX,tail was delayed significantly in marked APD extension RVOT cells compared to RV free wall cells,and the amplitude of INCX,tail in the former was larger than the latter ones(P<0.05).Conclusion In rabbit RVOT cardiomyocytes,prolonged APD might be the induction factor of delayed afterdeporization and EAD genesis.Under this precondition,the late-peaking and larger amplitude of INCX,tail in RVOT cells might play pivotal role in the mechanism of RVOT arrhythmogenesis.厦门市卫生局资助项目(No.A0000258

An Implementation of the Dynamic Loading Balance Cluster

讨论了网络负载平衡集群系统下,基本的平衡算法和动态负载平衡机制。在LVS的基础上配合轮询算法实现了集群的动态负反馈机制,给出了一个基本的动态平衡模型并加以分析。This article mainly discusses the basic arithmetic and mechanism of dynamic loading balance in the network loading balance clustering system. On the basis of the LVS(Linux Virtual Server) with the round robin arithmetic, we realize the degenerative feedback mechanism of cluster and bring forward a basic loading balance model , which is further analyzed

Analysis of Krawtchouk Moments Rotation Invariance

矩是基于区域的形状描述子,相对于基于轮廓的描述子例如傅立叶、链码描述子等,对于不连通的图像形状描述和对噪声的鲁棒性等方面有着更良好的性能。正交矩又可分为连续正交矩和离散正交矩,krAWTCHOuk矩是离散正交矩中的一种,和连续正交矩不同,基于离散正交矩本身的离散特性,更适合于对数字图像的处理。但同其他离散矩一样,krAWTCHOuk矩并不具备天然的几何不变性(旋转、缩放和平移),这也从一定程度上限制了krAWTCHOuk矩的应用。为使krAWTCHOuk矩得到更广泛的应用,对krAWTCHOuk旋转不变矩的构造进行详细分析和实验,比较出更适合用于浮游植物的krAWTCHOuk旋转不变矩。Moments is a shape descriptor based-on region,it has better performance for description of unconnected-region-image and robust against noise comparing to those methods based on contour such as fourier descriptor and chain-code descriptor.Orthogonal moments can glancing be divided into two categories,continuous orthogonal moments and discrete orthogonal moments.Krawtchouk moments is one of discrete orthogonal moments.By comparison,discrete moments is more suitable for digital image due to its discreteness.As other discrete-moments,Krawtchouk moments is not basic invariant with geometric transformation(rotation,scaling and translation),and Krawtchouk moments is not widely spread used in this case.To solve this problem,gives the suitable rotation invariant Krawtchouk moments,by comparing different methods and experiments.国家自然科学基金(No.40627001

Design and Implementation of an Embedded Browser Based on IPTV

介绍嵌入式浏览器发展背景及现状,提出一种基于IPTV(交互式网络电视)的嵌入式浏览器的设计方法。利用QT开放源代码中的WEbkIT模块,通过交叉编译和移植,设计和实现基于ST-9150板子上的嵌入式浏览器。并通过设计一些用户接口,能基本满足用户通过浏览器上网的需求。Introduces the background and development of embedded browser,proposes a design method of IPTV-based embedded browser.Designs and realizes an embedded browser by means of cross-compiling and porting the webkit module in the Qt open source codes to ST-9150 board.To satisfy user's need of accessing to the Internet through the browser,designs some user interfaces

The Design and Analysis of an General Network Driver Model in pSoSystem

在嵌入式平台上,由于大多数嵌入式操作系统都没有提供一个较为完整的驱动程序模型,从而使得驱动程序的开发较为复杂.而且每次开发的代码,其可重用性也很差.本文根据开发pSOS下网络驱动程序的实际经验,将独立于具体硬件的代码抽象出来,尝试提出了一种在pSOS下开发网络驱动程序的通用模型,以简化相应的开发工作和实现代码的最大重用.There are no provisions of a relatively integrated driver model by most of embedded operation systems in embedded flat, it makes the development of the driver more complicated.What's more, the reuse of the codes which are developed each time is rather bad. Based on our practical experiences of developing network driver in pSoSystem,we have abstracted the codes which are independent of entitative hardware.Then we intend to propose a General Network Driver Model in pSoSystem to simplify the development process and realize the maximal reuse of codes

Web Access Prediction Model Based on Markov Chain and Association Rule

用户访问预测是根据用户的历史访问信息和当前的访问路径预测用户下一步或将来可能访问的页面.因此可以利用预测结果提高服务器的性能,提高缓存的利用率和为用户提供个性化服务.提出了基于MArkOV链和关联规则的预测模型MAPM(MArkOV CHAIn And ASSOCIATIOn rulE PrEdICTIOn MOdEl),该模型首先使用二阶MArkOV链找到用户下一步或将来可能访问的页面集,生成预测候选集;然后再使用二项关联规则从正向和反向两个角度修正MArkOV的预测结果,从而生成最后的预测页面.User access prediction is the core of Web log mining,which predicts the next access page or the future access pages according to the history access information and the current access path.We can make use of the prediction result to improve the Web server performance,increase the cache utilization and provide users with personal service.In this paper we proposed Markov chain and association rule prediction model(MAPM).This model uses second-order Markov chain to find the pages which users may visit in next step or future,so as to generate the candidate prediction page set,and then corrects the Markov prediction result on forward and reverse perspective according to the two-items association rules,and gets the last prediction page.国家自然科学基金(40627001