AVIVO Video Converter通用版试用手记

在PSP上看电影的感觉无疑很爽，可每次把影片转换成PSP支持的格式往往会耗费大量时间，听说一款叫做AVIVO Video Converter的工具软件能快速转换视频格式，但是只支持Radeon X1000系列显卡，幸好网上还有适用于任何显卡的AVIVO Video Converter通用版。赶紧下载来试试吧……

给我速度,其余免谈 ATi Avivo Video Converter简测

随着 ATi 去年 Avivo 概念的提出,人们可以花费不多的资金就能享受到高素质的高清技术,所以越来越多的用户开始倾向于选购X1000系列显卡。使用拥有 Avivo 技术的显卡除了能够欣赏流畅、清晰的高清视频之外,还有什么能让我们觉得物超所值的东西呢?那便是 ATi 送给我们的一份大礼:Avivo VideoConverter——Avivo 视频转换器。

音频转换好帮手——dvdvideosoft Free Video to MP3 Converter

功能简介：dvdvideosoft Free Video to MP3 Converter是一个功能强大的音频工具，可以帮助你从视频中提取音频并输出为MP3格式。

A 12bit 300MHz Current-Steering CMOS D/A Converter

The proposed DAC consists of a unit current-cell matrix for 8MSBs and a binary-weighted array for 4LSBs,trading-off between the precision,speed,and size of the chip.In order to ensure the linearity of the DAC,a double Centro symmetric current matrix is designed by the Q2 random walk strategy.To achieve better dynamic performance,a latch is added in front of the current switch to change the input signal,such as its optimal cross-point and voltage level.For a 12bit resolution,the converter reaches an update rate of 300MHz.

A 16 bit Stereo Audio ΣΔ A/D Converter

A 16 bit stereo audio novel stability fifth-order ∑△ A/D converter that consists of switched capacitor ∑△ modulators, a decimation filter, and a bandgap circuit is proposed. A method for the stabilization of a high order single stage ∑△ modulator is also proposed. A new multistage comb filter is used for the front end decimation filter. The ∑△ A/D converter achieves a peak SNR of 96dB and a dynamic range of 96dB. The ADC was implemented in 0. 5μm 5V CMOS technology. The chip die area occupies only 4. 1mm × 2.4mm and dissipates 90mW.

一种高速A/D转换器时域重构技术研究

A/D转换器在航空航天系统中的重要元器件,随着器件转换时钟频率不断提高而其工作环境不断恶化,如何准确测试其时间参数对于全面评价A/D转换器性能特别重要。目前对于高速A/D转换器时间参数测试,主流方法是通过示波器直接测试其输出,该方法对于示波器采样速度要求比较高。文章提出一种高速A/D转换器时域重构技术,可以通过计算机数字信号处理方法来实现高速A/D转换器时间参数测试,同时避免对示波器采样速度的依赖。同时,在研究高速A/D转换器时域重构技术方法及其应用的基础上,通过了相关试验验证。

Numeric Simulation of Single Passage Ternary Turbulence Model in Hydraulic Torque Converter

Based on the renormalization group theory, a hydraulic torque converter 3 D turbulent single flow passage model is constructed and boundary condition is determined for analyzing the influence of the fluid field characteristic and parameters on the macroscopic model. Numerical simulation of the single fluid path is processed by computational fluid dynamics and the calculated results approach to experimental data well, and especially in low transmission ratio the torque and head results are more close to experimental data than the calculated results of beam theory. This shows that the appropriate ternary analysis method and reasonable assumption of boundary condition may analyze the flow field more precisely and predict the performance of torque converter more accurately.

A 10bit 2GHz CMOS D/A Converter for High-Speed System Applications

This paper presents a 2GS/s 10bit CMOS digital-to-analog converter （DAC） that consists of two unit current-cell matrixes for 6MSBs and 4LSBs, respectively, trading off between the precision and size of the chip. Current mode logic （CML） is used to ensure high speed,and a double centro-symmetric current matrix is designed by the Q^2 random walk strategy in order to ensure the linearity of the DAC. The DAC occupies 2.2mm × 2.2mm of die area and consumes 790mW with a single 3.3V power supply.

Soft transmission of 3D video for low power and low complexity scenario

Thanks to the rapid development of naked-eye 3D and wireless communication technology,3D video related applications on mobile devices have attracted a lot of attention.Nevertheless,the time-varying characteristics of the wireless channel is very challenging for conventional source-channel coding based transmission strategy.Also,the high complexity of source-channel coding based transmission scheme is undesired for low power mobile terminals.An advanced transmission scheme named Softcast was proposed to achieve efficient transmission performance for 2D image/video.Unfortunately,it cannot be directly applied to wireless 3D video transmission with high efficiency.This paper proposes a more efficient soft transmission scheme for 3D video with a graceful quality adaptation within a wide range of channel Signal-to-Noise Ratio(SNR).The proposed method first extends the linear transform to 4 dimensions with additional view dimension to eliminate the view redundancy,and then metadata optimization and chunk interleaving are designed to further improve the transmission performance.Meanwhile,a synthesis distortion based chunk discard strategy is developed to improve the overall 3D video quality under the condition of limited bandwidth.The experimental results demonstrate that the proposed method significantly improves the 3D video transmission performance over the wireless channel for low power and low complexity scenarios.

Performance Optimization of Torque Converters Based on Modified 1D Flow Model

A methodology for performance optimization of torque converters is put forward based on the one-dimensional (1D) flow model. It is found that the inaccuracy of 1D flow model for predicting hydraulic performance at the low speed ratio is mainly caused by the separation phenomenon at the stator cascade which is induced by large flow impinging at the pressure side of the stator blades. A semi-empirical separation model is presented and incorporated to the original 1D flow model. It is illustrated that the improved model is able to predict the circumferential velocity components accurately, which can be applied to performance optimization. Then, the Pareto front is obtained by using the genetic algorithm (GA) in order to inspect the coupled relationship among stalling impeller torque capacity, stalling torque ratio and efficiency. The efficiency is maximized on the premise that a target stalling impeller torque capacity and torque ratio are achieved. Finally, the optimized result is verified by the computational fluid dynamics(CFD) simulation, which indicates that the maximal efficiency is increased by 0.96%.

Numerical simulation of the flow field of a flat torque converter

A flexible flat torque converter was proposed to fulfill the requirement of miniaturization and power density maximization for automobiles.Constructed by two arcs joined by lines,the torus was designed directly from design path.The influence of flatness on the performance of the torque converter was evaluated.The software CFX and standard k-ε model were adopted to simulate the internal flow fields of the torque converter under different flatness ratios.The results indicated that the performance of the torque converter got worse as the flatness declined,but the capacity of pump increased.The efficiency and the torque ratio dropped slightly as the flatness ratio decreased.So the torque converter could be squashed appropriately to get high power density without too much efficiency sacrifice.But when the flatness ratio was below 0.2,there was a significant drop in the efficiency.

血清GSDMD、ACE2在小儿川崎病中的表达水平及临床意义研究

目的 探索血清焦孔素蛋白D(GSDMD)、血管紧张素转化酶2(ACE2)在小儿川崎病(KD)患儿中的表达水平及临床意义。方法 收集2020年1月至2022年1月该院诊治的90例KD患儿为KD组,根据KD患儿是否发生冠状动脉损伤(CAL),将KD组分为CAL组(32例)和非CAL组(58例),选取同期因急性呼吸道感染发热住该院的患儿50例为发热对照组,另选取同期该院儿外科行择期手术的腹股沟斜疝患儿50例为对照组。采用酶联免疫吸附试验检测血清GSDMD、ACE2水平。Pearson相关分析血清GSDMD、ACE2与临床指标的相关性。多因素Logisitic回归分析KD患者发生CAL的影响因素。受试者工作特征(ROC)曲线分析血清GSDMD、ACE2对KD患儿发生CAL的诊断价值。结果 KD组血清GSDMD、ACE2水平高于发热对照组和对照组,差异有统计学意义(均P<0.05)。相比于非CAL组,CAL组KD患儿发热持续时间、丙种球蛋白治疗时间、红细胞沉降率、血小板计数、C反应蛋白、GSDMD、ACE2水平均明显较高,而血钠、白蛋白明显较低,差异有统计学意义(均P<0.05)。Pearson相关分析结果,KD组患儿血清GSDMD、ACE2水平与发热持续时间、丙种球蛋白治疗时间、红细胞沉降率、血小板计数、C反应蛋白呈正相关(均P<0.05),与血钠、白蛋白呈负相关(均P<0.05)。多因素Logistic回归分析结果显示,血清GSDMD、ACE2升高是影响KD患儿发生CAL的独立危险因素。ROC曲线分析结果显示,血清GSDMD、ACE2两项联合检测KD患儿发生CAL的曲线下面积(AUC)及其95%CI为0.918(0.868~0.949),明显大于血清GSDMD、ACE2单项检测的AUC及其95%CI[依次为0.838(0.789~0.887)、0.865(0.811~0.912)],差异有统计学意义(Z=5.116、4.217,均P<0.05)。结论 血清GSDMD、ACE2两项联合检测对于KD患儿发生CAL具有较高的诊断价值。

A 128×128 SPAD LiDAR sensor with column-parallel 25 ps resolution TA-ADCs

This paper presents a design of single photon avalanche diode(SPAD)light detection and ranging(LiDAR)sensor with 128×128 pixels and 128 column-parallel time-to-analog-merged-analog-to-digital converts(TA-ADCs).Unlike the conventional TAC-based SPAD LiDAR sensor,in which the TAC and ADC are separately implemented,we propose to merge the TAC and ADC by sharing their capacitors,thus avoiding the analog readout noise of TAC’s output buffer,improving the conversion rate,and reducing chip area.The reverse start-stop logic is employed to reduce the power of the TA-ADC.Fabricated in a 180 nm CMOS process,our prototype sensor exhibits a timing resolution of 25 ps,a DNL of+0.30/−0.77 LSB,an INL of+1.41/−2.20 LSB,and a total power consumption of 190 mW.A flash LiDAR system based on this sensor demonstrates the function of 2D/3D imaging with 128×128 resolution,25 kHz inter-frame rate,and sub-centimeter ranging precision.

Analytical Modelling and Experiment of Novel Rotary Electro-Mechanical Converter with Negative Feedback Mechanism for 2D Valve

The manufacturing of spiral groove structure of two-dimensional valve(2D valve)feedback mechanism has shortcomings of both high cost and time-consuming.This paper presents a novel configuration of rotary electro-mechanical converter with negative feedback mechanism(REMC-NFM)in order to replace the feedback mechanism of spiral groove and thus reduce cost of valve manufacturing.In order to rapidly and quantitative evaluate the driving and feedback performance of the REMC-NFM,an analytical model taking leakage flux,edge effect and permeability nonlinearity into account is formulated based on the equivalent magnetic circuit approach.Then the model is properly simplified in order to obtain the optimal pitch angle.FEM simulation is used to study the influence of crucial parameters on the performance of REMC-NFM.A prototype of REMC-NFM is designed and machined,and an exclusive experimental platform is built.The torque-angle characteristics,torque-displacement characteristics,and magnetic flux density in the working air gap with different excitation currents are measured.The experimental results are in good agreement with the analytical and FEM simulated results,which verifies the correctness of the analytical model.For torque-angle characteristics,the overall torque increases with both current and rotation angle,which reaches about 0.48 N·m with 1.5 A and 1.5°.While for torque-displacement characteristics,the overall torque increases with current yet decrease with armature displacement due to the negative feedback mechanism,which is about 0.16 N·m with 1.5 A and 0.8 mm.Besides,experimental results of conventional torque motor are compared with counterparts of REMC-NFM in order to validate the simplified model.The research indicates that the REMC-NFM can be potentially used as the electro-mechanical converter for 2D valves in civil servo areas.

The Design of A/D Converter Circuit Adopting the Technology of PWM

This text has expounded the working principle of realizing A/D conversion that utilizes the timer within MCU and combinesthe technology of PWM. The design of hardware circuit, improved gradual approached trial arithmetic and relevant program design arediscussed in detail. And it has analyzed the resolution of A/D converter based on the technology of PWM, etc.

基于层次分析法与改进D-S理论的阀水冷系统状态评估

为了及时评估保障换流阀可靠运行的阀水冷系统运行状态,首先,分析了换流站阀水冷系统整体构成,选取主要历史数据和实时数据构建了评估指标体系,通过三角形函数和半梯形函数以及专家调查法确定各个指标的隶属度;其次,基于层次分析法确定各个评估指标权重,改进D-S理论建立阀水冷系统运行状态评估模型;最后,通过采集实际工程阀水冷系统主要指标数据对模型进行了验证,并以阀水冷系统滤芯清洗前后数据为例对评估结果进行了对比。结果表明,所建模型能够对阀水冷系统运行状态做出准确识别和评估,有利于运维人员及时掌控阀水冷系统运行状态,保障其可靠运行。

A VIDEO SPECTRUM SPLITTING ENCODING SCHEME BASED ON HUMAN VISION AND ITS COMPUTER SIMULATION

In this paper, a 3-D video encoding scheme suitable for digital TV/HDTV (high definition television) is studied through computer simulation. The encoding scheme is designed to provide a good match to human vision. Basically, this involves transmission of low frequency luminance information at full frame rate for good motion rendition and transmission of high frequency luminance signal at reduced frame rate for good detail in static images.

Interrupt CW Approach for IF Video Signal Real Time Simulating and Its Validity

To determine the feasibility and practicability of interrupt continuous wave (CW) approach proposed for real time simulating radar intermediate frequency(IF) video signal, theoretical analysis and computer simulation were used. Phases at two linked points between the end and beginning of adjoined frames are always consistent; the bias Doppler frequency for the time delay of A/D sampling start responds to that for target acceleration. No digital phase compensation is required at continuous points, and the interrupt CW approach has apparently practical values.

多模态影像学联合VEEG对FCD外科手术的指导价值

目的 探讨多模态影像学联合视频脑电图(VEEG)对局灶性皮质发育不良(FCD)导致的难治性癫痫的定位、定性及定量诊断在外科手术中的指导价值。方法 回顾性分析25例经手术证实为FCD的影像和VEEG表现,分析病变位置、形态、密度、信号、代谢,测量病变大小,并与外科手术结果对比。结果 所有患者均得到明确定位、定性及定量诊断,诊断符合率100%;磁共振(MRI)显示病灶皮质呈局限性带状或结节状增厚,病灶呈等和(或)高信号,多排螺旋CT(MSCT)检查显示大部分病灶呈偏低密度,少数伴点条状高密度,正电子发射计算机断层显像(PET)检查大部分病灶氟-18-脱氧葡萄糖(18FFDG)呈低代谢;联合VEEG及多模态影像学诊断并与手术结果相比较,差异无统计学意义(P=0.17>0.05,t=1.42)。结论 多模态影像学联合VEEG对FCD引起的难治性癫痫外科手术有极高的指导意义。