Abrupt motion tracking via intensively adaptive Markov-chain Monte Carlo sampling

The robust tracking of abrupt motion is a challenging task in computer vision due to its large motion uncertainty. While various particle filters and conventional Markov-chain Monte Carlo (MCMC) methods have been proposed for visual tracking, these methods often suffer from the well-known local-trap problem or from poor convergence rate. In this paper, we propose a novel sampling-based tracking scheme for the abrupt motion problem in the Bayesian filtering framework. To effectively handle the local-trap problem, we first introduce the stochastic approximation Monte Carlo (SAMC) sampling method into the Bayesian filter tracking framework, in which the filtering distribution is adaptively estimated as the sampling proceeds, and thus, a good approximation to the target distribution is achieved. In addition, we propose a new MCMC sampler with intensive adaptation to further improve the sampling efficiency, which combines a density-grid-based predictive model with the SAMC sampling, to give a proposal adaptation scheme. The proposed method is effective and computationally efficient in addressing the abrupt motion problem. We compare our approach with several alternative tracking algorithms, and extensive experimental results are presented to demonstrate the effectiveness and the efficiency of the proposed method in dealing with various types of abrupt motions.     

微型通用串行总线的研究动态和应用及传输模型

微型通用串行总线(Micro-USB)作为PC机及各类数码产品的主流接口,因其具有携带方便、传输速度快、易于扩展、总线供电等优点,尤其是其特殊的传输线模型,使其在通用计算机、嵌入式系统为主要应用领域的各种数字系统和设备中得到了广泛的应用,并获得制造商及用户的高度认可,具有广阔的发展前景.     

星图的限制性强诊断

首先证明在n维星图Sn中,当n≥3时如果存在点集S V(Sn),|S|=n-1使得Sn-S是非连通的,那么存在点v∈V(Sn),N(v)=S.进而证明当n≥3时,n+1维星图Sn+1是强n-可诊断的.即在星图系统中所有的错误点不都是某一个点v的邻点集N(v)时,n维星图Sn的限制性诊断度为n.     

Surface morphology of [110] a-plane GaN growth by MOCVD on [1■02] r-plane sapphire

Nonpolar a-plane [110] GaN has been grown on r-plane [1■02] sapphire by MOCVD, and investigated by high resolution X-ray diffraction and atomic force microscopy. As opposed to the c-direction, this particular orientation is non-polar, and it avoids polarization charge, the associated screening charge and the consequent band bending. Both low-temperature GaN buffer and high-temperature AlN buffer are used for a-plane GaN growth on r-plane sapphire, and the triangular pits and pleat morphology come forth with different buffers, the possible reasons for which are discussed. The triangular and pleat direction are also investigated. A novel modulate buffer is used for a-plane GaN growth on r-plane sapphire, and with this technique, the crystal quality has been greatly improved.     

Microstructure and optoelectronic properties of gallium- titanium-zinc oxide thin films deposited by magnetron sputtering

Gallium-titanium-zinc oxide(GTZO) transparent conducting oxide(TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic properties of GTZO thin films on Ar gas pressure were observed. The X-ray diffraction(XRD) and scanning electron microscopy(SEM) results show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. With the increment of Ar gas pressure, the microstructure and optoelectronic properties of GTZO thin films will be changed. When Ar gas pressure is 0.4 Pa, the deposited films possess the best crystal quality and optoelectronic properties.     

短波组网技术探讨

讨论了短波组网的特点和要求,综合了几种国外短波网络的体系结构、设计方案,以及用于短滤网络的应用技术,并对中国进一步发展短波网络技术提出建议。     

串行高速HF MODEM

描述了一种４８００ｂｐｓ串行ＨＦ ＭＯＤＥＭ,重点讨论了实现高速数据传输的自适应均衡和纠错编码技术,给出了计算机模拟结果。与ＭＩＬ－ＳＴＤ－１８８－１１０Ａ相比,这里给出的方案在白噪声信道下改善了４ｄＢ,在多径衰落信道下改善更明显。     

图像边缘提取的定位误差产生机理分析

本文分析了使用Dmarr的LOG方法检测图像边缘时,零交叉点定位误差的产生机理,指明边缘中心邻域关于边缘中心不对称是造成零交叉点定位误差的主要原因,各类边缘的零交叉点是否定位准确与噪声存在与否并无直接的联系,关键在于噪声是否破坏了边缘相对其中心的奇函数特性。     

Real-time teleconsultation with high-resolution and large-volumemedical images for collaborative healthcare

Real-time consultation between referring physicians or radiologists with an expert is critical for timely and adequate management of problem cases. During consultation, both sides need to: 1) synchronously manipulate high-resolution digital radiographic images or large volume MR/CT images; 2) perform interpretation interactively; and 3) converse with audio. We present a specifically designed teleconsultation system in a digital imaging and communication in medicine picture archiving and communication systems (PACS) clinical environment. The system uses bidirectional remote control technology to meet critical teleconsultation application requirements with high-resolution and large-volume medical images operated in a limited bandwidth network setting. We give the system design and implementation methods, and also describe the teleconsultation procedure and protocol used in this system. Finally, laboratory and clinical evaluation results are discussed     

Low-temperature sensitive, compressively strained InGaAsP active(λ=0.78-0.85 μm) region diode lasers

This letter reports comparative studies between (Al)GaAs versus InGaAsP active region edge-emitting semiconductor lasers for emission wavelength in the IR regime (λ=0.78-0.85 μm). High characteristic temperature T₀(200 K) and T₁ (450 K) edge-emitting diode lasers have been demonstrated by using the compressively strained (Δa/a=0,6%) Al-free (InGaAsP) active region with an emission wavelength of 0.85 μm. The high T₀ and T ₁ a result of low active-layer carrier leakage, will be beneficial for high-temperature and high-power operation. Implementation for InGaAsP-active VCSEL's with compressively strained InGaAsP-active layers and conventional DBR's is also discussed