22 research outputs found

    Analysis and Hardware Design of Fast Restoration Algorithm for Rotational Motion Blurred Images

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    近年来,旋转运动模糊图像的复原技术已经成为国内外数字图像处理领域的主要研究课题之一。该技术可以用来解决相机在成像过程中与物体之间的相对旋转运动导致的图像中某些有用信息被掩盖的问题,因此,该复原技术具有非常重要的应用价值。 论文首先介绍了与运动模糊图象恢复有关的理论基础,如推导了旋转运动模糊图像的退化模型,给出了图象质量评价的一些常用指标,阐述了逆滤波、有约束最小二乘方、维纳滤波和Richardson-Lucy四种恢复方法的原理,在有噪声和无噪声两种条件下对其做了运动模糊恢复实验,并根据当前的研究成果选择了在恢复效果以及计算时间上均优于其它算法的维纳滤波法。 分析研究了一种旋转运动模糊图像的...In recent years, restoration of rotating motion blurred images has become one of the main research subjects in digital image processing field at home and abroad. This technology can be used to solve the problem that precision-guided weapons can not accurately identify and track the target because of images fuzzy in high speed rotating flight process, and the problem that some useful information is...学位:工学硕士院系专业:信息科学与技术学院电子工程系_微电子学与固体电子学学号:2312009115268

    Research of Artificial Neural Network Arithmetic Based on FPGA

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    [中文文摘]基于FPGA的神经网络实现方法已成为实际实时应用神经网络的一种途径。本文就十多年来基于FPGA的ANN实现作一个系统的总结,例举关键的技术问题,给出详细的数据分析,引用相关的最新研究成果,对不同的实现方法和思想进行讨论分析,并说明存在的问题以及改善方法,强调神经网络FPGA实现的发展方向和潜力及提出自己的想法。另外,还指出基于FPGA实现神经网络存在的瓶颈制约,最后对今后的研究趋势作出估计。[英文文摘]FPGA implementation of Artificial Neural Networks(ANNs)has been an approach of actual real-time neural network.This paper systematically reviews the progress that has been made in this research area over a decade,and lists the typical technology issues,shows detailed data analysis and newest research results,Simultaneously different implementation techniques and design are discussed,then existing problems and realizition constrains can be presented as well as improvement solutions,the development direction and potential of FPGA implement of ANN are proposed.Eventually future developments are expected.大学生创新性实验项目(2007年78号

    FPGA Based Accelerator for Hardware/Software Co-Simulation

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    在系统设计中,硬件复杂电路设计的调试与仿真工作对于设计者来说十分困难。为了降低仿真复杂度,加快仿真速度,本文提出利用fPgA加速的思想,实现软硬件协同加速仿真。经过实验,相对于纯软件仿真,利用软硬件协同加速仿真技术,仿真速度提高近30倍,大大缩短了仿真时间。In system deign,debugging for the design becomes increasingly difficult and designers want more efficient and high-performance verification and debugging solutions.As the design becomes larger and more complex,the pure software simulation suffers from the speed problem.In this paper,we present a new debugging methodology:FPGA based accelerator for hardware/software co-simulation.Experimental results show that the performance gain is up to 30 times over the pure software simulation

    Preventive effect and mechanisms of 3,3-diindolylmethane on oxidative stress induced by hydrogen peroxide in HaCaT cells

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    目的:探究3,3'-二吲哚甲烷(dIM)对过氧化氢(H_2O_2)诱导人角质形成细胞(HACAT)氧化应激作用的预防效应及可能机制。方法:体外培养HACAT细胞,用H_2O_2建立氧化应激模型。采用CCk-8法检测不同浓度(1~20μMOl/l)dIM对HACAT细胞生长的抑制作用;流式细胞术检测dIM作用前后细胞内活性氧自由基(rOS)含量的变化;WESTErn blOT检测不同浓度dIM(0、5、10μMOl/l)对HACAT氧化应激相关蛋白核因子(nf-κb)和丝裂原活化蛋白激酶(MAPkS)磷酸化表达水平的影响。结果:成功建立了HACAT氧化应激模型。CCk-8法研究结果显示1-10μMOl/l dIM对HACAT细胞无明显毒性作用(P>0.05);流式细胞术检测结果表明10μMOl/l dIM预处理可有效预防由H_2O_2诱导的HACAT内rOS产生(P0.05).Flow cytometry results indicated that pretreatment with DIM(10 μmol/L) could inhibit the level of intracellular ROS(P<0.05).With increasing concentration of DIM,the levels of p-p38-MAPK,p-JNK and p-NF-κB were significantly depressed.CONCLUSION:DIM could protect HaCaT cells from H_2O_2-induced oxidative stress via suppressing production of ROS levels and down-regulating the expression of NF-κB and members of MAPKs.DIM might be used as an effective drug to treat or reduce oxidative stressmediated injury in skin cells.国家自然科学基金青年基金(81101562); 广东省科技计划项目(2012B060300005); 广东省自然科学基金(S2012010009633

    Analysis of Effects in a Low-activation Ferritic/Martensitic Steel by High-energy Heavy-ion Irradiation

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    Low-activation Ferritic/Martensitic steels are a kind of important structural materials candidate to the application in advanced nuclear energy systems.Possible degradation of properties and even failure in the condition of high-temperature and high helium production due to energetic neutron irradiation in a fusion reactor is a major concern with the application of this kind of materials.In the present work microstructural evolution in a 9Cr Ferritic/Martensitic steel(T92B) irradiated with 122 MeV 20Ne ions...中文摘要:低活化的铁素体/马氏体钢是先进核能装置(如聚变堆)的重要候选结构材料。在聚变堆实际工作环境下,由于高温和高氦产生率引起的材料失效是这类材料面临的一个重要问题。本项研究以兰州重离子加速器(HIRFL)提供的中能惰性气体离子束(20Ne,122 MeV)作为模拟辐照条件,借助透射电子显微镜,研究了一种低活化的9Cr铁素体/马氏体钢(T92B)组织结构的变化和辐照肿胀。实验结果表明,高温下当材料中晶格原子的撞出损伤和惰性气体原子沉积浓度超过一定限值时,材料内部形成高浓度的空洞,并且空洞肿胀率显著依赖于辐照温度和剂量;在马氏体板条界面及其它晶界处空洞趋于优先形成,并且在晶界交汇处呈加速生长。基于氦泡的形核生长与空洞肿胀的经典模型探讨了在不同辐照条件(He离子、Ne离子、Fe/He离子双束、快中子、Ni离子)下铁素体/马氏体钢中肿胀率数据的关联

    铅离子辐照注碳4H-SiC的红外光谱特性研究

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    主要研究了铅离子辐照注碳4H-SiC样品在3个不同退火温度下傅立叶变换红外光谱的变化。从红外谱的变化可以知道铅辐照注碳4H-SiC样品在一定深度内出现了非晶层,波数在960—1 450 cm-1范围内出现了干涉带,干涉带强度随着退火温度的升高而变弱。1 373 K退火后样品的卢瑟福背散射分析结果显示,一定深度内硅原子的背散射产额明显减少

    cryptographic properties of bomm

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    BOMM(byte-oriented memorial mixer)算法是一种基于字节操作的混合型带记忆的序列扰乱算法,因具备良好的密码学性质,一个新的流密码算法Loiss使用了它作为主要组件.建立了BOMM算法的5次代数方程系统,在此基础上讨论了针对Loiss算法的代数攻击的复杂度.此外还发现了BOMM算法的一个统计弱点,并分析了Loiss算法在一类弱密钥下的安全性.BOMM is a byte-oriented mixed type algorithm with memory,which is used to disorder a given byte sequence.It has been used as a main component in a new stream cipher called Loiss for having many good cryptographic properties.This paper builds an algebraic equation system with degree 5 for BOMM,and based on this equation system,discusses the complexity of algebraic attack on Loiss.In addition,the paper also discusses the statistic weakness of BOMM and gives an analysis of the security of Loiss under a specific class of weak keys

    离子辐照后4H-SiC晶体退火前后的光谱研究

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    分析了高能Pb27+辐照预注入12C+的和未预注入12C+ 4H-SiC样品在,退火前后傅立叶变换红外光谱和拉曼散射光谱的变化。从傅立叶变换红外光谱可以知道,900℃以上的退火使损伤层发生显著恢复;在拉曼散射光谱中可以看到1200℃退火后有石墨相的存在。实验结果说明,高温退火有利于损伤的恢复,使注入到碳化硅中的碳原子发生聚集并引起相变

    注入Ar~+的蓝宝石晶体退火前后光致发光谱的分析

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    对注入Ar+后不同晶面取向的蓝宝石晶体在不同退火条件下的光致发光谱进行了分析.分析结果表明:三种晶面取向的蓝宝石样品经Ar+注入后,其光致发光谱中均出现了新的位于506nm处的发光峰;真空和空气气氛下的退火均对样品在506nm处的发光有增强作用,不同晶面取向的样品发光增强程度不同,且发光增强至最大时的退火温度也不同,空气气氛下的退火使样品发光增强程度更为显著.由此可以看出,退火气氛、退火温度和晶面取向均对样品发光峰强度有影响

    氧化物粒子弥散强化的合金中界面对高温氦脆的抑制机理研究

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    探讨了在0.5Tm(Tm为材料熔点)温度附近一种氧化物粒子弥散强化的铁基合金中惰性气体离子辐照引起的组织结构变化.实验利用高能20Ne离子辐照材料样品至3个剂量水平.借助透射电子显微镜发现,即使在最高辐照剂量,材料的晶界处也没有发生空洞的加速生长,显著区别于相同辐照条件下传统铁基合金的组织结构变化.这个特点反映出氧化物粒子弥散强化合金具有在高温和高氦产生率的苛刻环境中(诸如在聚变堆内部)使用的潜力.晶界处空洞生长的抑制效应可归因于材料晶粒内部高密度的氧化物纳米颗粒的界面对惰性气体原子的有效俘获和对辐照缺陷的回复作用
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