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针对医学图像组织间不明显现象,提出了一种基于模糊规则和小波变换的医学图像锐化增强算法。对不同尺度的小波系数进行锐化增强时,首先根据该尺度低频系数中心像素与其邻域像素的相容性利用模糊规则自适应计算非线性细节增益系数。然后把增益系数与细节小波系数相乘,小波重建后得到增强图像。实验结果表明,提出的算法对图像细节进行增强的同时能够有效地抑制噪声。 相似文献
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提出了一种新的彩色图像自动平滑方法。该方法首先根据人眼视觉系统的空间模糊特性,由观测距离自动确定初始高斯模板;并进一步从人眼视觉感知中的彩色细节失明及同时对比特性出发,利用象素间的色差和位置关系确定最终的高斯权值矩阵。算法对图像进行平滑的同时,可以保持图像细节和边缘不变。实验结果表明了算法的有效性。 相似文献
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本文提出了一种指纹图像匹配中细节点方向的计算方法,这种算法利用细节点所在的纹线来计算细节点的方向,实验结果表明,此算法对计算指纹图像细节点方向是有效的。 相似文献
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本文提出了一种指纹图像匹配中细节点方向的计算方法,这种算法利用细节点所在的纹线来计算细节点的方向,实验结果表明.此算法对计算指纹图像细节点方向是有效的。 相似文献
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提出了一种新的基于线模式的指纹图像细节点匹配算法,这种算法先分别找出最佳匹配点对,确定相对旋转角度,较快地确定两个指纹的相关性,之后再搜索漏的匹配点对,去掉错误的匹配点对。算法受指纹增强、后处理的影响较小,细节点相似程度受其邻域细节点影响较小。介绍了算法的具体实现方法,并用实际指纹数据进行了测试。初步测试的结果表明,此算法是指纹图像细节点匹配的一种有效算法。 相似文献
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在图像平滑处理过程中,如何设计保持图像边缘和纹理细节的数字图像去噪滤波器一直是人们关注的热点问题。本文在统一描述数字全变差滤波算法(DTV)和数字双边全变差算法(DBTV)的滤波机制的基础上,利用图像像素间的近-远程相关性,分别定义近程相关性和远程相关性两个度量,建立了一种非局部图像滤波自适应双边加权机制,提出一种同时适合高斯噪声和脉冲噪声的非局部数字全变差滤波算法(NLTV)。实验验证了新算法在抑制噪声的同时具有较好的边缘细节和纹理保持性能。 相似文献
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基于偏序集理论的数据包络分析方法,通过引进适当的偏序关系,挖掘出决策单元之间的特殊关系。然而,随着决策单元所选取的投入产出指标个数的增加,决策单元之间的偏序关系变得越来越少。对此,通过引进决策单元之间的距离和适当的样本决策单元,建立决策单元之间的特殊关系,最终生成决策单元之间的格论关系,并引进相关定理及其算法。最后通过仿真结果表明了所提出算法的有效性和实用性。 相似文献
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服务网格环境下基于行为的双层信任模型的研究 总被引:10,自引:0,他引:10
在开放的服务网格中,为不同管理域之间建立信任关系并以此实现它们之间的协同工作是当前服务网格所面临的一个主要安全问题。为了提高服务网格的安全性和可扩展性,文中提出了一个服务网格环境下基于行为的分层信任模型,用以解决处于不同管理域的实体之间协同工作的安全问题。模型上层建立和维护具有不同安全策略管理域之间的推荐信任关系,下层负责处理管理者对域内实体的信任评估问题。在利用推荐信任值建立管理域间关系的过程中,给出了一种根据实际交往经验调整管理域间推荐信任值的算法。同时,给出了一种可行的推荐信任值综合处理方法。实验表明,分层行为信任模型具有较好的有效性和可扩展性。 相似文献
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Correlations between locally averaged host observations, at different times and places, hint at information about the associations between the hosts in a network. These smoothed, pseudo-continuous time-series imply relationships with entities in the wider environment. For anomaly detection, mining this information might provide a valuable source of observational experience for determining comparative anomalies or rejecting false anomalies. The difficulties with distributed analysis lie in collating the distributed data and in comparing observables on different hosts, in different frames of reference. In the present work, we examine two methods (Principle Component Analysis and Eigenvector Centrality) that shed light on the usefulness of comparing data destined for different locations in a network. 相似文献
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基于编码器-解码器的实体关系联合抽取模型解决了流水线模型存在的误差传递问题,但是以往基于编码器-解码器的模型还是存在两点问题:一是在解码阶段同时生成实体和关系,而两者是不同的对象,使得同一语义空间的映射降低了抽取效果;二是没有考虑不同关系之间的交互信息。针对这两点问题,提出了关系自适应解码模型。所提模型将实体关系联合抽取任务转化为对应关系的实体对生成任务。首先以编码器-解码器为基础,将不同关系分而治之;根据不同的关系来自适应输出相应关系的实体对,使解码阶段更专注于实体的生成。然后不同关系之间共享同一模型的参数,使不同关系之间的关联信息得以利用。所提模型在两种版本的纽约时报(NYT)公开数据集上进行了实验,其F1值比当前最先进的模型分别提升了2.5个百分点和2.2个百分点。实验结果表明,所提模型能够通过关系自适应解码的方式有效提升实体关系的联合抽取能力。 相似文献
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宋振超 《数字社区&智能家居》2007,(11):777-779
本文浅析了在多处理器体系结构上的调度实时任务的各种不同方法。我们首先比较了这些不同的解决方案,然后描述了一种调度任务集的方法。该方法基于端对端的任务调度,考虑任务间的线性优先约束以及任务对资源的需求。同时.这种调度方法的另外一个目的是尽量减少处理器间的通信代价。这个模型也考虑了不同处理器之间的不同通信带宽以及各种处理器拥有不同的处理性能。 相似文献
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This paper focuses on comparisons between the different methods of assessing repetitive hand activities. Various methods were used to measure hand force and repetitiveness of hand activities on 733 subjects in the study described by Bao et al. (2006). Two definitions of repetitiveness were used in analysis of detailed time studies of repetitive hand activities and four parameters of the American Conference of Governmental Industrial Hygienists (ACGIH) hand activity level (HAL) and the Strain Index methods were estimated by ergonomists and used to quantify repetitiveness. Hand forces were measured or estimated using three different methods: 1) measured with a force gauge or mimicked on a force gauge (force matching); 2) estimated by ergonomists using rating scales; 3) self-reports by subjects. The jobs were also evaluated using the ACGIH HAL and Strain Index methods when different repetitiveness quantification methods were used. Results showed that different definitions of repetitive exertion might lead to measuring different physical exposure phenomena and produce very different results. There were poor correlations between the measures of repetitiveness estimated by the different methods. Correlations between force quantifications using different methods were also poor. This suggests that parameters measured by different methods might not be interchangeable. Both the ACGIH HAL and Strain Index methods identified more 'hazardous' jobs when repetitiveness was estimated by ergonomists than when it was calculated by detailed time studies of forceful hand exertions. The Strain Index method identified more 'hazardous' jobs than the ACGIH HAL method. Overall, the between-methods agreements were found to be moderate to substantial. 相似文献
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A continuously variable transmission (CVT) is an emerging automotive transmission technology that offers a continuum of gear
ratios between desired limits. A chain CVT is a friction-limited drive as its performance and torque capacity rely significantly
on the friction characteristic of the contact patch between the chain and the pulley. Moreover, such a CVT is susceptible
to clearance formation due to assembly defects or extensive continual operation of the system, which further degrades its
performance and leads to early wear and failure of the system. The present research focuses on developing models to understand
the influence of clearance and different friction characteristics on the dynamic performance of a chain CVT drive. A detailed
planar multibody model of a chain CVT is developed in order to accurately capture the dynamics characterized by the discrete
structure of the chain, which causes polygonal excitations in the system. A suitable model for clearance between the chain
links is embedded into this multibody model of the chain CVT. Friction between the chain link and the pulley sheaves is modeled
using different mathematical models which account for different loading scenarios. The mathematical models, the computational
scheme, and the results corresponding to different loading scenarios are discussed. The results discuss the influence of friction
characteristics and clearance parameters on the dynamic performance, the axial force requirements, and the torque transmitting
capacity of a chain CVT drive. 相似文献