303 research outputs found

    A Study of De-noising Methods in Face Recognition System

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    人脸识别是近几年来非常受关注的研究课题之一,这一研究领域包括:图像处理、模式识别、计算机视觉、神经网络,心理学等多个交叉学科。人脸识别系统非常复杂,其中处理的对象都是人脸图像数据。从现实中获取的图像包含各种噪声信号,使图像数据和现实差距太大。为了快速有效的去除这些噪声信号,本文详细研究了各种去除噪声的方法和原理,通过试验以直观的方式研究几种去噪效果,指出各种方法的优缺点。提出了将小波去除噪声和特征提取相结合以及PCA在噪声去除和特征提取相结合的方法。Machine recognition of human face still and video im- ages is emerging an active research area including several disci- plines, such as: image processing, pattern recognition, computer vision, neural networks, psychology and so forth. The human face recognition system is complex which processes a large of image data. Obtained from reality environment, the images con- tain a lot of noise. In order to de- noise more effectively and quickly, several general de - noising methods and theories are carefully studied in the paper. Compared the methods through the experiences and got results, then, the advantage and disad- vantage of each method are pointed out. The novel methods are suggested, for example, combining wavelet de- noising with fea- ture extraction, combining de- noising with PCA.福建省自然基金(A0310005);; 国家留学回国人员基金资助(K13003

    Human Face Image Edge Detection Methods and Application

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    如何确定人脸特征并对这些特征进行有效的提取是非常关键而且复杂的。人脸边缘和轮廓是人脸非常重要的特征。该文研究了边缘检测的原理和各种算法,通过试验验证各种检测方法在人脸图像中对边缘的检测效果,讨论选用在不同阈值下检测的边缘,以及影响检测效果的因素。最后通过实例研究了人脸边缘检测在人脸检测和识别中的具体应用。How to define and extract the feature of human face is a key and complicated problem. The edge and contour of human face is one of important feature. This paper studies the theory of edge detection and different kinds of arithmetical methods. The experiment results are used to confirm the different methods which are employed to test the edge detection results of the human face image. It discusses the consequence of detection when the threshold is varying and the possible factors, which makes the different results. Finally, it studies the application of the edge detection in human face detection and recognition.福建省自然科学基金资助项目(A0310005);; 国家留学回国人员基金资助项目(K13003

    Autonomous Mobile Robotic Architecture and Development Research

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    【中文文摘】阐述了自主移动机器人体系结构的意义,并对分层式体系结构和包容式体系结构这两种典型体系结构详细比较分析后,在此基础上研究了基于两者优点的混合型体系结构。最后,对该领域的研究热点进行了阐述,并对未来的研究工作提出了建议。 【英文文摘】The signification of autonomous mobile robotic archi- tecture is studied in this paper. Hierarchical architecture and subsumption architecture are the two kinds of robotic architec- tures being compared in detail. Based on this analysis, the peper gets the results that the hybrid architecture has advantages of both two types of architectures. Finally, the paper puts forward the hot topics in this area and make some suggestions about the future research

    Study on the Model both Cutting Variable-speed of the Log-core Veneer Lathe and Moving Locus Model with Constant-speed Peeling

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    详细分析了无卡轴旋切机的工作原理,推导了旋切过程中刀刃进给速度与圆木直径的数学模型,同时得出旋切时间的近似计算式。从中可知,旋切过程中刀刃进给速度必须按一定规律变化才能保证旋切机正常工作。建立了旋切机恒线速旋切的运动轨迹模型,推导出旋切机恒线速旋切时间的精确计算式,并在此基础上提出了旋切时间简便的近似计算式。这些研究结果均可用于指导设计和进行实际生产。Working principle of log-core veneer lathe had been analyzed in detail,and the mathematical model between the knife-carriage feeding speed and the diameter of the log core was established,in the meantime,the approximation cutting time formula was also derived.The feeding speed must be changed with continuousness and a rule,which can let the lathe work well.Moving locus model of invariable-speed peeling was also founded,precision calculating formula of invariable-speed peeling was deduced.In the same time,the simplification cutting-speed formula was also derived.These results of the research will provide a guide for the designing and the producing practice

    Over-expression of Pygo2 Promotes C6 Cells Proliferation of Glioma

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    目的通过构建过表达PygO2的重组体上调PygO2表达,探讨其在大鼠胶质瘤C6细胞增殖中的作用及机制。方法重组体经ECOr I和HIndⅢ双酶切鉴定和dnA测序后,用脂质体2000将其转染大鼠胶质瘤C6细胞,采用WESTErn blOT检测外源PygO2蛋白表达,应用克隆形成实验和MTT法检测细胞增殖,流式细胞术检测细胞周期,采用WESTErn blOT检测过表达PygO2对C6细胞中CyClInd1、β-CATEnIn水平的影响,并采用细胞免疫荧光法检测其对C6细胞中CyClInd1、β-CATEnIn亚细胞定位的影响。结果双酶切和测序鉴定结果证实插入序列正确,重组体能有效上调PygO2表达。将重组体转染C6细胞上调PygO2表达后,细胞的生长增殖被显著促进,克隆形成显著增多,细胞周期进程从g1期至S期转变显著增强;且CyClInd1水平随之增高,亚定位无改变,β-CATEnIn水平和亚细胞定位无明显改变。结论成功构建了过表达PygO2的重组体,过表达PygO2通过增高CyClInd1水平,促进细胞从g1期进入S期,从而促进大鼠胶质瘤C6细胞增殖。Objective To up-regulate expression of Pygopus2(Pygo2) by construction of the recombinant vectors of over-expression of Pygo2 protein,and to explore the role and mechanism of over-expression of Pygo2 in C6 cells proliferation of glioma.Methods The recombinant plasmids were digested with EcoRⅠ and Hind Ⅲ to execute the restriction endonuclease identification,then the sequence analysis was assayed by DNA sequencing.The recombinant plasmids were transfected into cultured glioblastoma C6 cells using lipofectamineTM 2000.The exogenous Pygo2 protein level of C6 cells was detected by Western blot analysis.Colony forming assay and MTT assay were used to detect the cell proliferation,and cell cycle analysis was performed by flow cytometry analysis.The effect of Pygo2 over-expression on the level of cyclinD1 and β-catenin of C6 cells was detected by Western blot analysis,and the expression and subcellular location of cyclinD1 and β-catenin of C6 cells were further quantified by immunofluorescent staining.Results The recombinant plasmids were completely coincided with the designs by the restriction map and the sequence analysis,which up-regulated Pygo2 expression of C6 cells efficiently.After Pygo2 expression were up-regulated by transfected C6 cells with the recombinant plasmids,cells proliferation was promoted and colony forming was increased significantly,cell cycle progression from G1 to S transition was enhanced notably.Furthermore,the expression level of cyclinD1 was significantly increased without change of subcellular location,and the expression level and subcellular location of β-catenin were not changed obviously.Conclusion The recombinant vectors of Pygo2 over-expression were constructed successfully.Over-expression of Pygo2 promotes the growth of glioma cells by an increased expression of cyclinD1 to improve G1/S transition.重庆市自然科学基金资助项目(cstc2011jjA10110);重庆市教委科技基金资助项目(KJ100504);福建省自然科学基金资助项目(2009D002

    端面泵浦Nd∶YAG连续输出1052nm波长激光器

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    设计了一个简单紧凑的1052nm波长激光器。首次利用激光二极管(LD)端面泵浦Nd∶YAG晶体,使用镀有高度选择性介质膜的反射镜产生该波段的激光。激光阈值为0.3W,当808nm波长泵浦光功率达到18W时产生了3.5W的1052nm波长激光输出。光-光转换效率为20%,输出激光功率波动不超过3%

    Spatial distribution and correlation of environmental factors andchlorophyll a concentrations in the Bohai Sea during the summer of 2013

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    通过对2013年7月渤海海域26个站点温度、盐度、营养盐及叶绿素a(Chl a)浓度的空间分布特征及其相关性进行了分析,发现:受渤海水深和夏季陆源河流输入影响,近岸水域表现出明显的高温、低盐与高营养盐特征,且垂直变化特征不显著;在水深较深的辽东湾湾口和渤海海峡,海水呈现明显的层化现象,表层水温高于中底层,而表层盐度与营养盐浓度则低于中底层。营养盐结构分析表明,渤海夏季磷酸盐浓度存在显著的绝对与相对限制,而受河流输入影响,硅酸盐的相对限制得到显著缓解。表层Chl a浓度的高值区位于滦河及复州河河口附近海区,中层与底层的高值区则出现在滦河与黄河口附近。Chl a浓度与环境因子的相关性分析表明,盐度..

    Microbial Degradation of Petroleum Hydrocarbons by Acinetobacter sp. BZ-15,Isolated from Contaminated Soil

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    本研究旨在从土壤中筛选高效石油烃降解菌株,并对其系统分类和降解特性进行研究,为石油污染的原位修复奠定基础.该研究从滨州油井溢油污染土壤样品中分离得到一株高效石油烃降解菌株BZ-15,对菌株BZ-15进行形态观察、16S r RNA基因序列分析及系统发育树分析;对该菌株的生长特性进行研究;通过GC-MS分析其对原油组分中不同碳原子饱和烃的降解特性;同时研究吐温-20对其生长及降解特性的影响;对该菌株中的烷烃羟化酶基因alk M进行了克隆.结果表明,菌株BZ-15为不动杆菌属(Acinetobacter sp.)细菌,在LB培养基中其代时为3.25 h,添加吐温-20代时为2.67 h,吐温-20..

    ST段抬高型急性心肌梗死院前溶栓治疗中国专家共识

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    急性心肌梗死仍然严重威胁我国人民健康,在我国广大城乡地区,形势更为严峻[1,2]。及时救治急性心肌梗死患者,降低死亡率和保护心脏功能刻不容缓。鉴于我国的实际情况,院前溶栓治疗在大城市以外的城乡地区具有重要意义。为此,中国医师协会胸痛专业委员会及中国医学救援协会心血管急救分会专门组织有关专家制订了本共识,旨在帮助院前医疗急救人员对急性心肌梗死患者选择最佳

    第十八届美国理论与应用力学大会总结

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    1会议概况2018年6月5—9日,第18届美国理论与应用力学大会(18th U.S. National Congress of Theoretical and Applied Mechanics, USNCTAM2018)在美国芝加哥召开.本次大会由美国力学国家委员会和中国力学学会联合主办,旨在探讨和交流近四年世界范围内在理论和应用力学领域的基础研究、创新技术的最新进展,吸引了来自世界各地的近千名专家学
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