音频的数字化处理技术探究

随着计算机网络技术的发展,音频的数字化处理技术的应用越来越广泛。本文阐述了音频信号的定义,并从音频信号的采集、量化、编码、压缩、噪声处理、提取、抗混迭滤波等方面对音频信号的数字化处理进行了阐述。通过本文的分析论述对音频数字化技术有了全面的认识,为其应用奠定了理论基础。     

基于分布式原理的多信源音频编码技术研究

基于分布式信源编码原理的多信源编码是一个全新的编码方式,将其应用于音频编码以降低音频信源采集的难度,是音频处理技术的全新领域。在分析分布式编码理论的基础上,提出了多信源编码在音频编码中的应用思路,设计了一种采用多信源分布式编码实现音频编码的方案,进行了计算机仿真分析,对多信源音频编码的实用化具有重要的现实意义。     

切莫忽视音频处理器的作用

本文从故障实例出发对音频处理器的作用进行了阐述。并对怎样正确使用音频处理器，使其发挥更大的效能，进行了技术分析和研究。     

音频的数字化处理技术探究

随着计算机网络技术的发展，音频的数字化处理技术的应用越来越广泛。本文阐述了音频信号的定义，并从音频信号的采集、量化、编码、压缩、噪声处理、提取、抗混迭滤波等方面对音频信号的数字化处理进行了阐述。通过本文的分析论述对音频数字化技术有了全面的认识，为其应用奠定了理论基础。     

如何合理有效地使用音频处理器

本文对Orban9200音频处理器的主要技术指标和特点进行了简单的分析和介绍,并就如何合理有效地使用音频处理器及如何发挥其更大的效能,进行了阐述.     

QSC新一代网络音频解决方案：Q—Sys系统（一）

2009年,美国QSC公司隆重推出了其新一代网络音频解决方案：Q—Sys系统,该系统由业内顶尖的研发团队耗时3年打造完成。Q—Sys系统是一个完整的系统平台,可完成从音源输入到音箱输出的整个音频链路的所有功能。Q—Sys系统可以对所有音频信号进行路由分配和信号处理,对必要的设备进行控制和监测,并保持了高质量的音频信号品质和可靠性。     

基于AD8332和AD8368的低噪声放大器的设计

由于音频信号在无线传输过程中受到各种干扰,所以损耗比较大,在接收端接收到音频信号以后,首先要对比较微弱的音频信号的电平或者幅度进行一定程度的放大.低噪声放大器（LNA）的主要作用是对通过选频网络的音频小信号进行放大,给予其电平或幅度一定的增益.结合AD8332和AD8368芯片,设计了一种应用在无线音频接收机电台的低噪声放大器（LNA）.     

音频的高清发展之道

欧胜微电子日前发布了其在高清晰度音频领域里的愿景,其高清晰度音频方案旨在为各种下一代多媒体应用建立音频基准。一直以来,人们习惯了听到高清视频这样的字眼,但随着越来越多的消费者对音频质量的关注。     

基于通用型DSP的前端音频信号的处理方案

在多媒体系统设计和实现中,需对音频进行采集。但在对音频进行采集的同时也要对视频信号进行处理,因音频的数据量少,又要求连续采集,故在两者的协调性和保证数据完整性方面存在难度。就此提出一种基于通用型DSP芯片的前端音频信号的处理方案,利用视频的采集间隙,储存音频数据,以实现在视频和音频的采集不同步的情况下,利用最少的资源,实现其在保证数据采集完整性的同时不与视频采集冲突。     

广州国际媒体港音频网络设计

广州国际媒体港作为广州市广播电视台战略转型升级的核心项目,有着与传统电视台建设不同的业务流程以及技术框架。本文通过对现有广电音频网络发展的分析,并依据媒体港对音频业务的发展需求,提出了以AOIP技术为核心的IP音频网络架构,并对其优势进行了详细阐述。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.