H.264变换和量化算法研究

详细分析了H.264视频编码标准中的整数变换原理,阐述了与变换相关的量化过程.H.264标准中采用了4×4块的整数变换算法,并将尺度调整融合在量化过程中,有效地降低了编解码的运算量,且不存在反变换的匹配误差,精度更高.最后给出了变换和量化算法的软硬件实现方法.     

H.264变换编码与量化原理分析

详细分析了 H .2 64视频编码标准中的整数变换和量化过程。 H .2 64采用 4× 4整数变换 ,并将尺度调整融合在量化过程中 ,降低变换算法复杂度和减少乘法次数 ,相对于以前的编码标准更加有效     

H.264变换编码及量化策略分析

H.264采用4×4的整数变换替代通用的8×8DCT变换.并将其融合在量化过程中,有效降低了变换算法的复杂度和运算量.避免了逆变换的失配问题.对H.264变换编码及量化策略进行了详细的分析,给出了其具体的实现过程.     

H.264中的基于全零块检测的运动搜索方法

运动搜索和变换域编码是视频编码标准H.264中运算量很大的部分,为了减少视频编码的运算量,本文根据H.264运动搜索和整数变换的特征,提出了一种H.264下的全零块检测方法。在帧间编码中,该方法在运动搜索中和变换前,对运动补偿的差值数据进行全零检测,检测的门限根据绝对误差和(SAD)和量化参数而定。在运动搜索非常准确时,就可以找到全零块,就停止搜索,可以省却后面的搜索运算和全零块的整数变换以及相应的量化运算,在基本保持H.264原有编码算法的图像质量的同时,减少了运算量,缩短了码流,提高了编码器的编码效率。     

一种基于FPGA高性能H．264变换量化结构设计

H.264作为最新的视频编码标准具有很高的压缩性能,对它的研究具有重要的意义.根据H.264的变换量化算法设计一种基于FPGA的高性能变换量化处理结构,该结构采用流水线探作和分时复用技术,结果显示,该设计既节省了资源,又保证了效率;能够同时处理整个4×4块的全部16个残差输入数据,并在236个时钟内完成对1个宏块的残差数据从输入到反变换输出重建值的完整变换量化过程.它的处理速度和性能大大提高,可用于硬件加速.     

H．264整数DCT的FPGA实现

H.264整数DCT变换算法有助于减少计算复杂度,提高编码速度,进一步提高视频或图像的压缩效率。分析H.264整数DCT变换的快速算法及其实现原理,并提出一种用来具体实现一个4×4块的DCT变换的结构;同时给出用VHDL语言实现4×4块DCT变换的内部模块的源代码和仿真波形。仿真结果表明用该算法可快速实现一个4×4块的整数DCT变换。提出一种切实可行的用于H.264整数DCT变换的结构,该结构可完全用硬件电路快速实现;对于用FPGA实现H.264整数DCT变换做了一次实践性的尝试,对深入理解H.264整数DCT变换及其算法的具体实现具有一定的实践意义。     

基于H.264标准的一种新颖的DCT硬件实现

H.264是新一代视频编码标准,具有很好的视频压缩性能.H.264的DCT变换是一种4×4的整数变换,适用于专用集成电路的硬件实现.采用一种新颖的实现方法,利用4-2压缩器和超前进位加法器来代替传统的加法,提高了运算速度.     

H.264中一种基于矩阵分解的变换算法及硬件实现

H.264是新一代的视频编码标准，具有优秀的压缩性能。其获得优越性能的代价是运算复杂度的大幅增加，因此在实际应用上存在困难。使用专门的硬件设备是解决这个问题的方法之一。H．264标准中的整数变换运算适合使用硬件实现。首先对H，264标准中的整数变换运算进行介绍，针对H．264中的变换运算提出一种基于矩阵分解的快速并行算法。分析了该算法的结构，表明是符合H.264标准的一种快速算法。并对变换算法的硬件寡现进行了分析，表明这种硬件算法结构适合在实时编解码中应用。     

H.264/AVC视频编码及其在IPTV中的应用

文章首先介绍了关于IPTV(交互式网络电视)的国际视频编码标准——H.264/AVC的特点以及采用的主要技术,包括整数变换和量化、帧内预测、帧间预测、熵编码和环路滤波。对H.264/AVC在IPTV中的应用优势做了阐述,并就它们在IPTV中的应用发展做了一些合理的分析。     

一种H.264视频编码码率控制方法

根据视频编码线性率失真函数和对H．264整数变换量化方法分析，提出一种适合于H．264编码算法的码率控制算法。先验证线性率失真函数对H．264编码算法的适用性，再通过将H．264整数变换的量化分解为系数校正和统一量化两个步骤实现了线性率失真函数在H．264码率控制中的应用。实验证明，与JVT—G012码率控制算法相比，码率控制的准确性和信噪比均有所提高。     

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.     

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.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-