排序方式: 共有98条查询结果,搜索用时 15 毫秒
81.
媒体资源功能(MRF)是IP多媒体子系统(IMS)中的一个重要功能实体,负责提供媒体资源.本文介绍了一种MRF的设计和实现方案,该方案不仅适用于IMS网络,同样适用于广义的下一代网络. 相似文献
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《电子学报:英文版》2016,(4):625-631
Bird strikes present a huge risk for air ve-hicles, especially since traditional airport bird surveillance is mainly dependent on ine?cient human observation. For improving the effectiveness and e?ciency of bird monitor-ing, computer vision techniques have been proposed to detect birds, determine bird flying trajectories, and pre-dict aircraft takeoff delays. Flying bird with a huge de-formation causes a great challenge to current tracking al-gorithms. We propose a segmentation based approach to enable tracking can adapt to the varying shape of bird. The approach works by segmenting object at a region of inter-est, where is determined by the object localization method and heuristic edge information. The segmentation is per-formed by Markov random field, which is trained by fore-ground and background mixture Gaussian models. Exper-iments demonstrate that the proposed approach provides the ability to handle large deformations and outperforms the m ost state-of-the-art tracker in the infrared flying bird tracking problem. 相似文献
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对于如何抑制正电子发射成像(positron emission tomography,PET)中的噪声效果的问题,Bayesian重建或者最大化后验估计(maximum a posteriori,MAP)的方法在重建图像质量和收敛性方面具有相对于其他方法的优越性.基于Bayesian理论,本文提出了一种新的能够保持其先验能量函数凸性的马尔可夫随机场(Markov Random Fields,MRF)混合多阶二次先验(quadratic hybrid multi-order,QHM),该QHM先验综合了二次-阶(quadratic membrane,QM)先验和二次二阶(quadratic plate,QP)先验,且能够根据不同阶数的二次先验和待重建表面的性质自适应的发挥QM先验和QP先验的作用.文中还给出了使用该新的混合先验的收敛重建算法.模拟实验结果的视觉和量化比较证明了对于PET重建,该先验在抑制背景噪声和保持边缘方面具有很好的表现. 相似文献
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TANG HongZhe Beihang Sino-French Engineer School Beihang University Beijing China 《中国科学:物理学 力学 天文学(英文版)》2011,(7)
Dispersion of metal particles in fluids can be used to manufacture magnetorheologic fluids(MRF).Properties of these dispersion systems are mainly determined by the arrangements and contacts among particles.In this paper,particles with smaller sizes than those in the target dispersion system are added using iron particles dispersed in silicon oil as a model to control the arrangements and contacts.The result suggests that these small-sized particles have a significant effect on the viscoelastic properties of... 相似文献
86.
This research is aimed at the development of computer-aided polishing technology for optical surfaces using magnetorheological (MR) fluid as medium.The mechanism of a dual-axis polishing wheel and the mathematical model combined with a symmetrical tool function are demonstrated.The effects of speed,gap,time and geometric parameters of the tool have been experimentally evaluated by polishing a parabolic BK7 mirror in 120mm diameter.The surface topography presented an obvious amelioration,and the shape accuracy decreased to 0.067λ from 0.519λ(λ=632.8nm,RMS) after 75min finishing. 相似文献
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Noise-interference is one of the major concerns in low-power VLSI circuits. Due to power supply downscaling, these circuits have an extremely limited noise margin that is inadequate for dealing with intrinsic and extrinsic noise. The MRF-based design has been accepted as a highly effective method for designing noise-tolerant low-power circuits. However, the MRF-based circuits suffer from a complex structure and the methods which tried to simplify the structure always sacrificed the noise immunity for hardware simplicity. In this paper, we propose a novel MRF-based method for designing efficient and reliable low-power VLSI circuits. For the first time, an innovative reliability boosting mechanism based on maximum conditional correct probability is incorporated into an efficient MRF-based structure which leads to highly reliable circuits with considerably low cost, delay, and power consumption. The proposed method demonstrates the best performance among all of the previously reported methods. Moreover, the Monte Carlo simulations confirm that the proposed method can preserve its superior noise immunity even under serious process, voltage, and temperature variations. 相似文献
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Chen Yi-nan Jin Wei-qi Wang Ling-Xue Zhao Lei Yu Hong-sheng 《Optics Communications》2009,282(5):786-3936
An image blind reconstruction, as a blind source separation problem, has been solved recently by independent component analysis (ICA). Based on ICA theory, in this paper, a high resolution image is reconstructed from low resolution and subpixel shifted sequences captured by infrared microscan imaging system. The algorithm has the attractive feature that neither the prior knowledge of the blur kernel nor the value of subpixel misregistrations between the input channels is required. The statistical independence in the image domain is improved by the multiscale Gabor subband decompositions, which are designed for the best ability to cover the whole spatial frequency and to avoid overlapping between the subbands. The mutual information is employed to locate a subband with the least dependent components. In terms of MAP estimator, we combine the super-Gaussian with Markov random field to form a hybrid image distribution. This strategy helps to estimate the separating matrix reasonable to extract the sources with the image properties, that is, sharp enough as well as correlative in local area. The proposed algorithm is capable of performing high resolution image sources which are not strictly independent, and its viability is proved by the computer simulations and real experiments. 相似文献
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针对平面旋转场下磁流变液中诱导产生的层状结构,提出了恰当的理论模型,该模型成功的解释了层状结构在同步旋转状态下:层间距随磁场的变化关系;旋转层的滞后角随旋转角频率以及其他物理量之间的关系;层半径与旋转角频率之间的关系.理论结果与文献中发表的实验结果相吻合. 相似文献