Wire congestion estimation in a bounded-bend model

Interconnect congestion estimation plays an important role in the physical design of integrated circuits. Fast congestion analysis prior to global routing enhances the placement quality and improves the routability for the subsequent routing phases. This article presents a novel congestion estimation method for a wire layout with bounded detours and bends. Experimental results on benchmarks demonstrate the efficiency and accuracy of our approach.     

Implementation of a real-time passive ultrasonic angle estimator for autonomous low power ranging and tracking systems

Indoor localisation technologies have received considerable attention in recent years and they are applicable in many fields. As with outdoor systems, they both suffer degradation in performance when multi-path errors are present. Applications include locating essential equipment in hospitals and specific items in warehouses, tracking people with special needs, who are away from visual supervision, and navigating firefighters inside buildings. In this article, we study issues associated with the implementation of a passive low cost, low computational complexity and low power consumption ranging and tracking system using ultrasonic sensor arrays. Due to the physical limitation of these sensors, they are placed in a zig-zag configuration to simulate an approximate linear array. To perform localisation, this system utilises the matrix pencil algorithm to estimate the direction-of-arrival (DOA) of the signal based on the phase delays of the array elements whereas the range estimation is performed by triangulation, based on DOA information from two identical arrays. Multi-access capability is also implemented to accommodate a multiple-transmitter environment. We present real-time experimental results to illustrate the satisfactory performance of the ranging and tracking system in an indoor environment setup.     

MIMO-OFDM系统信道估计技术的分析

介绍了MIMO—OFDM系统的信道估计技术，根据是否使用训练序列信息，信道估计可以分为导频辅助信道估计和盲信道估计，本文首先较全面地介绍了导频辅助信道估计技术，然后介绍了一种运用较多的基于子空间的盲信道估计技术，最后计算机仿真分析比较它们的性能。     

直升机目标被动声跟踪算法及其仿真研究

本文提出了包含多普勒和声传播时间延迟的接收信号模型;提出了在直升机目标做匀速直线运动的条件下,将声基阵获得的测向信息与多普勒频移信息融合,估计目标运动参数的算法,并用蒙特卡罗方法分析了该算法的估计精度;仿真结果表明该算法可实现较高的估计精度,测距精度满足实用要求;最后研究了应用该算法的自适应跟踪问题．     

Low computational complexity family of affine projection algorithms over adaptive distributed incremental networks

This paper presents the problem of distributed estimation in an incremental network based on the family of affine projection (AP) adaptive algorithms. The distributed selective partial update normalized least mean squares (dSPU-NLMS), the distributed SPU-AP algorithm (dSPU-APA), the distributed selective regressor APA (dSR-APA), the distributed dynamic selection of APA (dDS-APA), dSPU-SR-APA and dSPU-DS-APA are introduced in a unified way. These algorithms have low computational complexity feature and close convergence speed to ordinary distributed adaptive algorithms. In dSPU-NLMS and dSPU-APA, the weight coefficients are partially updated at each node during the adaptation. In dSR-APA, the optimum number of input regressors is selected during the weight coefficients update. The dynamic selection of input regressors is used in dDS-APA. dSPU-SR-APA and dSPU-DS-APA combine SPU with SR and DS approaches. In these algorithms, the weight coefficients are partially updated and the input regressors are optimally/dynamically selected at every iteration for each node. In addition, a unified approach for mean-square performance analysis of each individual node is presented. This approach can be used to establish a performance analysis of classical distributed adaptive algorithms as well. The theoretical expressions for stability bounds, transient, and steady-state performance analysis of various distributed APAs are introduced. The validity of the theoretical results and the good performance of dAPAs are demonstrated by several computer simulations.     

RETF: a TCP-Friendly Control Scheme Based on Rate Estimation for Stored Video

1　IntroductionTheInternethasrecentlybeenexperiencinganexplosivegrowthintheuseofreal timemultimediaservices.Real timemultimedia,asthenameim plies ,hastimingconstraints.Toavoidtheunac ceptabledelayintroducedbyretransmission ,real timemultimediaapplicationsusually preferUDP .However,aconsiderableamountof greedyUDPtrafficwoulddominatemuchnetworkbandwidth .Asaresult,theavailablebandwidthtoTCPconnec tionsisoppressedandtheirperformanceextremelydeteriorates.InorderforbothTCPandUDPses sionstof…     

Gaussian-Hermite moment-based depth estimation from single still image for stereo vision

Depth information of objects plays a significant role in image-based rendering. Traditional depth estimation techniques use different visual cues including the disparity, motion, geometry, and defocus of objects. This paper presents a novel approach of focus cue-based depth estimation for still images using the Gaussian-Hermite moments (GHMs) of local neighboring pixels. The GHMs are chosen due to their superior reconstruction ability and invariance properties to intensity and geometric distortions of objects as compared to other moments. Since depths of local neighboring pixels are significantly correlated, the Laplacian matting is employed to obtain final depth map from the moment-based focus map. Experiments are conducted on images of indoor and outdoor scenes having objects with varying natures of resolution, edge, occlusion, and blur contents. Experimental results reveal that the depth estimated from GHMs can provide anaglyph images with stereo quality better than that provided by existing methods using traditional visual cues.     

Fast Encoding Method for Image Vector Quantization Based on Multiple Appropriate Features to Estimate Euclidean Distance

The encoding process of finding the best-matched codeword (winner) for a certain input vector in image vector quantization (VQ) is computationally very expensive due to a lot of k-dimensional Euclidean distance computations. In order to speed up the VQ encoding process, it is beneficial to firstly estimate how large the Euclidean distance is between the input vector and a candidate codeword by using appropriate low dimensional features of a vector instead of an immediate Euclidean distance computation. If the estimated Euclidean distance is large enough, it implies that the current candidate codeword could not be a winner so that it can be rejected safely and thus avoid actual Euclidean distance computation. Sum (1-D), L₂ norm (1-D) and partial sums (2-D) of a vector are used together as the appropriate features in this paper because they are the first three simplest features. Then, four estimations of Euclidean distance between the input vector and a codeword are connected to each other by the Cauchy–Schwarz inequality to realize codeword rejection. For typical standard images with very different details (Lena, F-16, Pepper and Baboon), the final remaining must-do actual Euclidean distance computations can be eliminated obviously and the total computational cost including all overhead can also be reduced obviously compared to the state-of-the-art EEENNS method meanwhile keeping a full search (FS) equivalent PSNR.     

Zerstörungsfreie risstiefenbestimmung in Betonbauwerken mittels Radiotracerverfahren

At the Leipzig Technical University a method was developed, which allows to determine nondestructive the crack depth in concrete up to 15 cm. Based on a radiotracer technique the access to only one side of the object is required. The labelling of artificial-made cracks was carried out by use of a transport medium (not miscible with water) on the base of methyl isobutyl ketone (MIBK) and In- 113m as radionuclide. For the calculation of crack depth, measure-geometrical parameters were used. The improvement of the reliability of building-diagnostical interpretation using radio-physical parameters is described. A first application is provided for concrete structures below chemical equipments built as a barrier against ecologically harmful substances (petrol tanks). The intersectional aspect of further qualifications of the technique is emphasized.