Efficient Design of Low Delay Nonuniform Cosine Modulated Filter Banks Based on Gradient Information

An efflcient approach to the design of low delay nonuniform filter bank is presented which is derived from a uniform cosine modulated filter bank. In this derived nonuniform filter bank, the analysis and synthesis filters are combinations of the cosine modulated versions of a prototype filter. The design problem is formulated as a quadratic unconstrained least squares minimization prob- lem, in which the gradient vector of the objective function with respective to unknown parameters can be obtained analytically. A design example and comparisons are in- cluded which show that the proposed design method leads to filter banks with improved performance.     

谈喷印机喷印工艺与油墨性能的关系

喷印机的喷印过程中,喷印质量直接受油墨性能和喷印工艺参数的影响。本文从喷印机的实用性出发,主要分析探讨了在保证喷印质量的情况下喷印工艺参数的设定与油墨性能的相互关系,并对喷印工艺参数的设定和油墨的使用提出了一些量化指标,为使用者在选择油墨及对油墨性能进行调整和改善提供一定的参考依据,对喷印机的实际应用也有着一定的指导意义。     

N-channel thin-film transistors constructed on plastic by solution processes of HgSe nanocrystals

We demonstrate bottom-gate thin-film transistors (TFTs) based on solution-processed HgSe nanocrystals (NCs) on plastic substrates. Solid films made of spin-coated HgSe NCs were heated at a temperature of 150 °C for 15 min to maximize the magnitude of their current, and these films were utilized as the channel layers of TFTs. A representative TFT with a bottom-gate Al₂O₃ layer operated as a depletion-mode one with an n-channel, exhibiting a field effect mobility of 3.9 cm²/Vs and an on/off current ratio of about 10². In addition, the electrical characteristics of the TFT on bent substrates are briefly described.     

针对C、C++语言开发的软件进行回归测试中的系统静态分析技术

软件回归测试在软件测试中扮演着重要的角色.C Test原型系统是一个自动化测试驱动系统.它主要功能包括:对C、C 源程序进行静态分析和预处理;生成系统扩展有限自动机模型;进行依赖分析;进行回归测试,最后生成测试报告.本文主要探讨在具体系统中进行回归测试时的系统静态分析实现技术.     

雷达回波图像的补偿与优化

经过信号处理过的雷达视频数据或多或少都会造成一些回波细节损失。此外,把极坐标的雷达视频数据转化成直角坐标的视频图像也会产生摩尔纹,造成视频图像的缺损。本文在终端显示之前运用一些图像处理算法,对雷达图像进行修复与细节增强,以得到更饱满更真实的回波图像,为终端显示软件的开发提供一些新思路。     

Optical and Electrical Properties of TixSi1‐xOy Films

Ti_xSi_1xO_y (TSO) thin films are fabricated using plasma‐enhanced atomic layer deposition. The Ti content in the TSO films is controlled by adjusting the sub‐cycle ratio of TiO₂ and SiO₂. The refractive indices of SiO₂ and TiO₂ are 1.4 and 2.4, respectively. Hence, tailoring of the refractivity indices from 1.4 to 2.4 is feasible. The controllability of the refractive index and film thickness enables application of an antireflection coating layer to TSO films for use as a thin film solar cell. The TSO coating layer on an Si wafer dramatically reduces reflectivity compared to a bare Si wafer. In the measurement of the current‐voltage characteristics, a nonlinear coefficient of 13.6 is obtained in the TSO films.     

A design of a high-speed and high-efficiency capsule endoscopy system

This paper presents a high-speed and high-efficiency capsule endoscopy system. Both a transmitter and a receiver were optimized for its application through an analysis of the human body channel. ON-OFF keying modulation is utilized to achieve low power consumption of the in-body transmitter. A low drop output regulator is adopted to prevent performance degradation in the event of a voltage drop in the battery. The receiver adopts superheterodyne structure to obtain high sensitivity, considering the link budget from the previous analysis. The receiver and transmitter were fabricated using the CMOS 0.13-μm process. The output power of the transmitter is -1.6 dB·m and its efficiency is 27.7%. The minimum sensitivity of the receiver is -80 dB·m at a bit error ratio (BER) of 3 × 10 (-6). An outer wall loop antenna is adopted for the capsule system to ensure a small size. The integrated system is evaluated using a liquid human phantom and a living pig, resulting in clean captured images.