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71.
组播因其在点对多点传输方面拥有的优势,常被用于多媒体会议等应用。但是由于使用组播路由规模的限制,阻碍了在因特网推广组播技术的应用。首先对组播的原理作了分析,提出了具有组播特性的包含多个目的IP地址的IP传输设计,然后描述了一些关键问题,并讲解了具体设计和实现方法。  相似文献   
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73.
A fundamental challenge for time-varying volume data analysis and visualization is the lack of capability to observe and track data change or evolution in an occlusion-free, controllable, and adaptive fashion. In this paper, we propose to organize a timevarying data set into a hierarchy of states. By deriving transition probabilities among states, we construct a global map that captures the essential transition relationships in the time-varying data. We introduce the TransGraph, a graph-based representation to visualize hierarchical state transition relationships. The TransGraph not only provides a visual mapping that abstracts data evolution over time in different levels of detail, but also serves as a navigation tool that guides data exploration and tracking. The user interacts with the TransGraph and makes connection to the volumetric data through brushing and linking. A set of intuitive queries is provided to enable knowledge extraction from time-varying data. We test our approach with time-varying data sets of different characteristics and the results show that the TransGraph can effectively augment our ability in understanding time-varying data.  相似文献   
74.
A superhydrophobic micromesh covered with nanoprotrusions has been introduced and its applicability to a waterproof mobile phone speaker has been evaluated. The nanotextured superhydrophobic micromesh showed excellent water repellency, self-cleaning and waterproofing performances. In a waterproof speaker test using the fabricated nanotextured micromesh, the micromesh did not lose its waterproof function at 2 m water depth and did not form a remnant water film after being removed from the water. The packaged speaker showed almost the same sound quality before and after dipping at a 2 m water depth. These results demonstrate that the superhydrophobic nanotextured micromesh could be directly applicable for various products that need to resist water penetration, yet allow the transmission of gases and sound/light waves.  相似文献   
75.
In this paper, a class of stochastic impulsive high-order BAM neural networks with time-varying delays is considered. By using Lyapunov functional method, LMI method and mathematics induction, some sufficient conditions are derived for the globally exponential stability of the equilibrium point of the neural networks in mean square. It is believed that these results are significant and useful for the design and applications of impulsive stochastic high-order BAM neural networks.  相似文献   
76.
This paper presents the design and fabrication of a micro Pirani gauge using VO x as the sensitive material for monitoring the pressure inside a hermetical package for micro bolometer focal plane arrays (FPAs). The designed Pirani gauge working in heat dissipating mode was intentionally fabricated using standard MEMS processing which is highly compatible with the FPAs fabrication. The functional layer of the micro Pirani gauge is a VO x thin film designed as a 100 × 200 μm pixel, suspended 2 μm above the substrate. By modeling of rarefied gas heat conduction using the Extended Fourier’s law, finite element analysis is used to investigate the sensitivity of the pressure gauge. Also the thermal interactions between the micro Pirani gauge and bolometer FPAs are verified. From the fabricated prototype, the measured device TCR is about −0.8% K−1 and the sensitivity about 1.84 × 10−3 W K−1 mbar−1.  相似文献   
77.
无论是普适计算还是物联网,实时定位均是其关键技术之一。在建筑物、洞室等复杂环境中,由于无线信号的不规则衰减、非视距传播,使得常用的一些定位算法(如接收信号强度、到达角度等)无法达到较高的定位精度。为了解决复杂环境中定位精度不足的问题,设计并实现了一个定位精度改进中间件。它集成了平滑、传感器融合、卡尔曼滤波、粒子滤波等多种精度改进策略,可以根据用户对定位精度的需求动态地选择相应的策略。通过实验分析了不同精度改进策略的性能,结果表明,该中间件能够较好地满足用户对不同精度的需求。  相似文献   
78.
The traditional sphere-structured support vector machines algorithm is one of the learning methods. It can partition the training samples space by means of constructing the spheres with the minimum volume covering all training samples of each pattern class in high-dimensional feature space. However, the decision rule of the traditional sphere-structured support vector machines cannot assign ambiguous sample points such as some encircled by more than two spheres to valid class labels. Therefore, the traditional sphere-structured support vector machines is insufficient for obtaining the better classification performance. In this article, we propose a novel decision rule applied to the traditional sphere-structured support vector machines. This new decision rule significantly improves the performance of labeling ambiguous points. Experimental results of seven real datasets show the traditional sphere-structured support vector machines based on this new decision rule can not only acquire the better classification accuracies than the traditional sphere-structured support vector machines but also achieve the comparable performance to the classical support vector machines. An erratum to this article can be found at  相似文献   
79.
80.
In this paper, we propose a novel Retinex image enhancement approach by adopting two important prior named brightness channel prior (BCP) and change of detail (CoD) prior. We first derive a rough illumination map estimation method via BCP and Retinex model. Then, we present a combination refining method which involves the guided filter and a new total variation (TV) smoothing operator to eliminate the block effect in the rough illumination map while maintain the local smoothness property. In addition, we propose a novel sharping algorithm rely on CoD prior to improve the visual effect of the degraded image. Experimental results verify that our approach outperforms current approaches in terms of effectiveness, efficiency and universality.  相似文献   
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