人民币冠字号码高速识别实时模板生成算法

在回顾了目前人民币冠字号码识别研究文献的基础上,提出了一种在高速走钞环境下用于识别冠字号码的实时模板生成算法.首先在装有CIS的验钞机上采集到足够完备的人民币图像,然后抠出冠字号码区域,对其进行倾斜校正、二值化处理、形态学处理、字符分割及高度归一化后,对每种字符位图生成对应的模板集合,再根据差异最大化的原理从模板集合中挑出5个形成最终的模板精简集合.最后,给出了应用此模板进行实时识别的效果数据及分析.     

基于LabVIEW的人民币冠字号识别系统研究

系统的工作方式主要是对人民币采集图像,然后进行包括图像灰值化、滤波、倾斜校正及对冠字号目标区域提取的图像预处理,随后利用LabVIEW中Vision Assistant工具里的OCR功能对冠字号中出现的字符进行训练并建立模板数据库,与提取出的冠字号区域进行匹配从而识别出字符并转换成文本。系统用户操作界面简洁,具有较高的识别准确率及速度。     

纸币号码识别技术研究

研究了纸币号码识别技术.针对水平冠字号和垂直冠字号的特点,分别对号码数字图像进行了预处理、去噪、分割等处理,然后利用区域模板矩阵作为特征参数,进行模板匹配实现号码识别,并对一些易混淆的字符进行特殊区域信息比较.在实践中水平冠字号的识别率达98%,垂直冠字号的识别率达93%.     

一种基于特征加权模板匹配方法在纸币字符识别中的应用

纸币字符是纸币的重要特征之一,一组字符能够唯一标识纸币的身份.能够快速地识别纸币中的字符直接影响到纸币字符识别的精度和速度.本文运用特征加权模板匹配算法,设计了一个纸币字符识别算法.该算法从当前应用最广泛的模板匹配法入手,对标准模板匹配算法加以改进,从而提高了纸币字符实别的效率和精度.该算法能够充分区分开字符笔画和非笔画部分对字符识别的影响大小,从而有效地提升了识别率和鲁棒性.从实验结果来看,该算法性能较优.     

消噪和数学形态学结合的字符图像预处理算法

噪声污染字符图像的预处理是字符识别技术中一项关键技术,字符识别的准确度直接取决于字符图的质量。基于消噪和数学形态学的基本原理,提出了一种预处理算法。仿真实验验证了所提出新算法的有效性和可行性。这种算法不仅能消除图像中的噪声,而且还有效地修复了笔划断裂的字符。新算法解决了识别笔划缺损字符的识别难点,从而间接地提高了字符识别技术的准确度。     

字符识别中的畸变字符校正算法研究

文章提出了一种基于模板匹配的畸变字符识别算法。该算法可以自动校正由于柱面透视投影所引起的畸变字符图像,显著提高柱面字符识别的正确率。然后对校正后的图像进行字符定位,最终通过模板匹配算法对字符做出判决。试验结果表明,畸变字符校正算法有效地提高了算法对于圆柱面上字符的识别能力,在测试中取得了良好的效果。     

基于BP神经网络的文本验证码破解

以某游戏网站的验证码为例,介绍了基于文本图像验证码的识别和破解过程。破解过程分为字符提取、字符修正和字符识别。在字符提取阶段需要对图片进行预处理降低提取难度,提取主要采用了近似颜色统计法;在字符修正阶段对比了传统的旋转算法和改进旋转算法,然后归一化字符;在字符识别阶段采用了BP神经网络方法,对验证码的识别正确率达70％,每个验证码的平均破解时间为1．625s。     

基于Android平台的视频字符实时识别研究

针对移动终端处理能力低、内存小等影响系统效率的问题,提出了三阶段视频字符实时识别方法：视频采集及图像预处理、字符区域定位和字符识别。对于字符区域定位,提出了基于感兴趣区域（ROI,Region of Interesting）运动检测的相似帧过滤算法,并通过数学形态学与连通区域相结合的方法进行字符定位;对于字符识别,提出了基于误差阈值筛选的多模板字符识别算法,保证较高识别率。算法均采用NDK开发框架实现。实验结果表明,该方法在每个阶段都提高了处理效率,达到了对视频字符实时识别的效果。     

基于隐马尔可夫模型的车牌自动识别技术

文中提出了一种车牌字符识别的新方法,用二维隐马尔可夫模型方法识别车牌中的汉字,用伪二维隐马尔可夫模型（P2D－HMM）方法识别车牌中的英文字符及阿拉伯数字。该算法适用于不同的字符大小、字符倾斜、污损等情况,抗噪声能力强。字符识别正确率达94％以上,满足实用技术的要求。     

切线距离在车牌字符识别中的应用

针对车牌字符识别中字符变形失真影响识别率的问题,文章提出一种基于切线距离的车牌字符识别算法。首先对车牌字符图像进行预处理,在先验知识的基础上确定切线向量,然后通过核主成份分析对样本图像和切线向量降维,并引入切线距离度量样本之间的相似度,最后利用K-NN分类器对字符进行识别。实验结果表明,该算法有效地保留了车牌字符的非线性信息,减少了识别时间,并且显著提高了识别率。     

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.     

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.     

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.     

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.     

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.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its