An Efficient Rerouting Scheme for MPLS-Based Recovery and Its Performance Evaluation

The path recovery in MPLS is the technique to reroute traffic around a failure or congestion in a LSP. Currently, there are two kinds of model for path recovery: rerouting and protection switching. The existing schemes based on rerouting model have the disadvantage of more difficulty in handling node failures or concurrent node faults. Similarly, the existing schemes based on protection switching model have some difficulty in solving problem such as resource utilization and protection of recovery path. This paper proposes an efficient rerouting scheme to establish a LSP along the least-cost recovery path of all possible alternative paths that can be found on a working path, which is calculated by the upstream LSR that has detected a failure. The proposed scheme can increase resource utilization, establish a recovery path relatively fast, support almost all failure types such as link failures, node failures, failures on both a working path and its recovery path, and concurrent faults. Through simulation, the performance of the proposed scheme is measured and compared with the existing schemes.     

北缘蔗区甘蔗专用留种田栽培技术研究(续完)──Ⅲ.蔗种茎粗对大田生产的影响的研究

本研究以湘北蔗区常规甘蔗品种NCo310为材料,在1998年进行甘蔗蔗种茎粗对大田生产的影响试验,观察了甘蔗的出苗率、有效茎数、株高、茎粗、单茎重、产量等农艺性状,结果表明蔗种茎粗对大田生产有显著影响,当蔗种茎粗小于1．7cm时,甘蔗大田生产产量显著减少,本研究表明甘蔗中小茎品种如NCo310等只有当播种行距在0．5。～0．6m时,才能获得较多茎粗大于1．7cm的甘蔗种芽．通过1996～1998年三年研究表明,在北缘蔗区建立甘蔗专用留种田栽培制度是切实可行的,但要适当的控制行距和密度．采用甘蔗专用留种田栽培技术,可以明显地提高北缘蔗区的甘蔗生产水平。     

基于分层神经网络的宽频段DOA估计方法

该文提出了一种采用智能识别技术解决宽段来波方位估计的新方法。提取已知来波方位信号的协方差矩阵的上三角部分作为样本特征,然后构建区域估计和方位估计的分层模型,实现对未知来波方位的精确估计。所提出的分层方法降低了模型构造的复杂度,实现了宽频段来波方位估计。给出了应用该方法的具体步骤。仿真实验结果表明,该方法具有很高的测向精度,具有广阔的应用前景。     

Automated coronal hole segmentation from Solar EUV Images using the watershed transform

Region of interest segmentation in solar images is the subject of frequent research in solar physics. This study outlines watershed by immersion segmentation to identify coronal hole areas in solar images acquired using the Extreme UV Imaging Telescope (EIT). Solutions presented here produce highly accurate segmentation results of coronal holes of irregular shape, and what is more, they do so for images representing varied solar activity, recorded in different years and months. In addition, the solutions presented here make all the methods used operate very quickly. These methods include: the preprocessing step before the watershed segmentation, the watershed segmentation itself, and also the postprocessing of solar images after the watershed segmentation. The mean duration of the entire segmentation process of solar images amounts to 342 ms for a single coronal hole, without the parallel implementation of the methods used. The experiments were carried out on a computer with an Intel Core i7 CPU @ 2 GHz and 4 GB RAM. After the seed point is identified inside the coronal hole, the segmentation runs automatically.     

基于JPEG2000的遥感图像感兴趣区域编码新算法及其VLSI设计

为解决空间遥感图像数据量及信道带宽之间的矛盾,该文提出一种基于JPEG2000的感兴趣区域(Region Of Interest, ROI)编码算法。主流的JPEG2000 ROI编码算法难以兼顾ROI质量和系统计算量,且在低码率编码时有完全丢失背景的隐患。该算法通过精确控制各子带中背景系数的精度,使ROI分配到更多码流。并引入了人眼视觉特性,使较少的背景码流产生尽量好的视觉效果。另外,根据该算法提出了针对矩形ROI的超大规模集成电路(VLSI)设计,此设计经过简单调整,亦可适用于主流的ROI编码算法。测试结果表明,该算法在ROI质量和重建图像视觉效果上均表现优异,且支持任意形状ROI编码,兼容JPEG2000协议。该VLSI设计仅使JPEG2000系统运行时间增加一个周期,具有极高的吞吐率,可满足实时处理要求。     

甲状腺结节超声图像分割算法研究

超声甲状腺结节分割是发现与识别甲状腺良恶性肿瘤的关键技术之一.针对模糊聚类法无法准确分割超声图像甲状腺结节边缘,而局部拟合(RSF)模型法对手动初始化轮廓敏感的问题,提出一种融合空间约束模糊C均值聚类和局部拟合RSF模型的分割结节方法.用空间约束模糊C均值聚类法(SKFCM)对图像进行聚类并二值化聚类结果作为RSF模型法初始轮廓,克服了RSF模型法对初始轮廓敏感问题,水平集演化参数也将通过聚类结果自动给出,不再需要人为设定.同时改进了RSF模型法拟合项,并利用高斯正则化规则RSF模型水平集,提高了RSF模型演化效率,缩短了收敛时间.仿真实验结果表明,提出的甲状腺结节超声图像分割方法能够快速准确地分割出结节区域.     

A multi-object image segmentation C–V model based on region division and gradient guide

The Chan–Vese (C–V) model is an ineffective method for processing images in which the intensity is inhomogeneous. This is especially true for multi-object segmentation, in which the target may be missed or excessively segmented. In addition, for images with rich texture information, the processing speed of the C–V is slow. To overcome these problems, this paper proposes an effective multi-object C–V segmentation model based on region division and gradient guide. First, a rapid initial contour search is conducted using Otsu’s method. This contour line becomes the initial contour for our multi-object segmentation C–V model based on a gradient guide. To achieve the multi-object segmentation the image is then converted to a single level set whose evolution is controlled using an adaptive gradient. The feasibility of the proposed model is analyzed theoretically, and a number of simulation experiments are conducted to validate its effectiveness.     

基于FB-FDE的地空通信窄带干扰抑制方法

提出了一种基于滤波器组的单载波频域均衡(FB-FDE)技术的窄带干扰抑制方法,该方法在多径时延较大的地空宽带通信中具有很强的窄带干扰抑制能力。从理论上详细分析了基于滤波器组的窄带干扰抑制技术能够克服基于FFT频域均衡缺点的主要原因,并在此基础上提出了基于自适应子带合并的算法。理论分析和仿真试验均表明,该方法抑制窄带干扰能力强,运算简单,适于工程实现。     

一种基于概念格的本体合并方法

提出了一种基于概念格的,并利用叙词表的方法进行本体合并.为了进一步获得提取本体概念的相关指导,提高本体概念抽取的自动化程度,提出最小外延集概念,从而更方便有效地进行本体合并.     

An innovative two-stage data compression scheme using adaptive block merging technique

Test data has increased enormously owing to the rising on-chip complexity of integrated circuits. It further increases the test data transportation time and tester memory. The non-correlated test bits increase the issue of the test power. This paper presents a two-stage block merging based test data minimization scheme which reduces the test bits, test time and test power. A test data is partitioned into blocks of fixed sizes which are compressed using two-stage encoding technique. In stage one, successive blocks are merged to retain a representative block. In stage two, the retained pattern block is further encoding based on the existence of ten different subcases between the sub-block formed by splitting the retained pattern block into two halves. Non-compatible blocks are also split into two sub-blocks and tried for encoded using lesser bits. Decompression architecture to retrieve the original test data is presented. Simulation results obtained corresponding to different ISCAS′89 benchmarks circuits reflect its effectiveness in achieving better compression.