模板运算的传递函数分析

以均值滤波、边缘增强为例介绍了图像处理中模板运算的频域分析方法,说明如何运用模板的传递函数来分析模板的滤波特性,提出了分离模 板的条件、方法。并对模板的设计提出了一些建议。     

Dejittering in the transport of MPEG-2 and MPEG-4 video

When multimedia information is transported over a packet-switched network, the quality of presentation can be degraded due to network delay variation or jitter. This paper presents a dejittering scheme that can be used in the transport of MPEG-4 and MPEG-2 video to absorb any introduced network jitter, thus preserving the presentation quality of transported media streams. The dejittering scheme is based on the statistical approximation of delay variation in the arrival times of video packets carrying encoded clock reference values and a filtering and re-stamping mechanism. In addition, a brief overview of the MPEG-4 system is presented.     

光电脉冲编码器四倍频电路的实现及其应用

就光电编码器的实际应用问题及解决方法,提出并设计了一套适用于精度要求较高的位移检测方法及实现电路。末以欠驱动器臂的控制为例,介绍其具体应用。     

基于Mellin变换的语音新特征与频率归正说话人自适应技术

为了减小由于说话人之间声道形状的差异而引起的非特定人语音识别系统性能的 下降,研究了两种方法,一种是基于最大似然估计的频率归正说话人自适应方法,另一种是基 于Mellin变换的语音新特征.在非特定人孤立词语音识别系统上的初步实验表明,这两种方 法都可以提高系统对不同说话人的鲁棒性,相比之下,基于Mellin变换的语音新特征具有更 好的性能,它不仅提高了系统对不同话者的识别性能,而且也使系统对不同话者的误识率的 离散程度大大减小.     

从语音信号中提取情感特征的研究

分析了含有欢快、愤怒、惊奇、悲伤等 4种情感的语音信号的时间构造、振幅构造和基频构造的特征。通过和不带情感的平静的语音信号的比较 ,总结了不同情感语音信号情感特征的分布规律 ,为情感信号处理和识别提供了有实用价值的理论数据。     

Application of the independent molecule model to elucidate the dynamics of structure I methane hydrate: a second report

Two model systems of methane hydrate are constructed. One has a small cage surrounded by 12 large cages. The other has a large cage surrounded by four small cages and ten large cages. Three different H-bonding network patterns between waters are formed, and three random configurations of methane in each cage are chosen. A new method called the surface water fixed model is presented in which the energy minimum conformations for both model systems are preserved close to the X-ray crystallized structure. With normal mode analysis, we calculated frequencies of 2916.6 cm⁻¹ for a small cage at a centre, 2915.9 cm⁻¹ not at a centre, and 2911.7 cm⁻¹ for a large cage at a centre, and 2911.3 cm⁻¹ not at a centre. These frequencies are in moderate agreement with the corresponding Raman spectra, though not adequate. With our new method, however, it should be possible to improve agreement with the Raman spectra, if a model system vastly larger than the present model systems were constructed.     

Structural, electronic, and magnetic properties of heterofullerene C(58)Si with odd number of atoms and a near planar tetracoordinate Si atom

Density functional calculations and minimization techniques have been employed to characterize the structural and electronic properties of [5,6]-heterofullerene-C₅₈Si-C_2v. Since it has odd number of atoms and a near planar tetracoordinate Si atom on the skeleton of the cage, it has odd number of atoms assembling a cage and is a novel molecule. Vibrational frequencies of the molecule have been calculated at the B3LYP/6-31G* level of theory. The absence of imaginary vibrational frequency confirms that the molecule corresponds to a true minimum on the potential energy hypersurface. Sixteen ¹³C nuclear magnetic resonance (NMR) spectral signals of C₅₈Si are characterized, and its heat of formation was estimated in this work.     

Prototypical implementation of location-aware services based on a middleware architecture for super-distributed RFID tag infrastructures

We provide evidence of the feasibility and effectiveness of a middleware architecture for mobile devices (MoDs), which employs dense distributions of small computerized entities for providing fault-tolerant location-aware services. We do so by describing exemplary implementations based on radio frequency identification as an enabling technology. Firstly, we present prototypical implementations of the hardware abstraction layer and of selected core middleware services. The latter enable a MoD to store and retrieve data and position information in physical places in a fault-tolerant manner, and to identify places based on a location abstraction which is robust against failure of individual tags. Secondly, we investigate the feasibility of some higher-level services and applications by developing and evaluating prototypical systems for tracing and tracking, self-positioning, and collaborative map-making.

基于UML的电牵引采煤机变频器控制器的建模设计

针对矿用电牵引采煤机电气控制系统传统的设计过程存在的设计缺陷,文章提出了一种在系统设计初期采用UML建模方法进行系统的需求分析与设计的方案,并以矿用电牵引采煤机电气控制系统中变频器控制器的建模设计为例,介绍了基于UML的建模设计方法。     

结构振动控制仿真分析软件TSHOW

介绍结构振动控制仿真分析软件TSHOW基于结构振动控制的算法和原理,建立了在无控、主动控制、隔振控制和半主动控制时结构运动的微分方程,并应用MATLAB控制系统工具箱（Control System Toolbox）中的函数,研制了仿真分析程序。对于实验结果,经TSHOW进行后处理,可以与仿真结果进行对比,从而分析控制实验的效果。仿真结果以图形方式显示,内容包括控制力时程、所选楼层的动力响应等,例如位移、速度、加速度时程。频域分析包括位移、速度、加速度的幅频响应曲线。所绘曲线的显示特性可以按照要求进行设置和调整。为了探求隔振层和控制装置的动力特性,利用图形技术,实现了层间恢复力-位移曲线的动态显示。