苍南广电网络现状及整改对策

根据苍南县广电网络的现状和整改方案,从主干线和用户网改造两个角度出发,比较使用电缆和光缆的价格和性能差异,从而得出光缆的性价优于电缆的结论,同时提出了用光缆实现双向改造的两个方案,最后给出了苍南双环光网的实例.     

窄带多通道滤光片的设计与制备

介绍了三种获得窄带多通道滤光片的方法。第一种方法是具有缺陷的多异质结结构,该结构能够展宽光子晶体的禁带同时实现多通道效应。第二种方法是多通道导模共振布儒斯特滤光片,此类滤光片可以采用单层膜结构来实现多通道效应,也可以采用具有相等折射率的双层膜结构来实现多通道效应。第三种方法是组合刻蚀法制备窄带滤光片列阵。该方法不仅可以制作单腔窄带滤光片列阵,还可以制作双腔窄带滤光片列阵。窄带多通道滤光片在光学领域中具有一定的应用前景。     

Nonvolatile floating-gate memory programming enhancement using well bias

A nonvolatile memory programming approach using ohmic and Schottky well bias contacts is proposed. Programming efficiency using positive and negative bias voltages are compared in addition to electric field differences between the biases and type of contacts using experimental data and simulations. High-injection efficiency of electrons to the floating-gate is achieved using a negatively biased Schottky contact and a positively biased ohmic contact. A low-injection efficiency is achieved using a negatively biased ohmic contact and a positively biased Schottky contact.     

基于自然语言处理的新冠疫情文献分析与研究

随着时间推移,COVID-19对人类的影响与日俱增,人们很难迅速找到自己需要的文章,缺少合适的检索工具,浪费大量的时间和精力,文章提出了一种新的检索方法。该方法首先采用线性化归一对文章数据进行预处理,其次使用NLP从每个文档的正文中解释文本,然后使用TF-IDF将每个文档实例转换为特征向量,接着用t-SNE对每个特征向量进行降维,将相似的文章聚集在二维平面中,再使用PCA将数据投影到多个维,采用K-means聚类,最后用LDA建模,从每个聚类中发现关键字,在可视化图形上可视地查找聚类。该方法可以帮助专业人员更容易地筛选出许多与病毒有关的出版物,并快速找到他们需要的文章。     

Proposal of Novel Optical Polarity-Reversing Correlator for Optical CDMA Radio Highway Network

This paper proposes a new optical polarity-reversing correlator for opticalCDMA radio highway network. We theoretically analyze thecarrier-to-interference-plus-noise power ratio of regenerated radio signal atthe control station. Analysis results clarify that optical CDMA using bipolarcode sequences can be applied to the fiber-optic link of radio highway and wecan assign more distinct code sequences to radio base stations compared withthe unipolar type correlator using prime codes. By the proposed opticalpolarity-reversing correlator using Gold codes, thecarrier-to-interference-plus-noise ratio can be more improved than theunipolar type correlator using prime codes. It is also found that for smalltransmitted optical peak power, the proposed optical polarity-reversingcorrelator using Gold codes can improve the number of maximum connected radiobase stations much more compared with the unipolar type correlator using primecodes.     

车辆牌照字符的提取

车辆牌照字符的提取是牌照自动识别系统中几大关键步骤之一。本文先用小角度Hough变换对倾斜的牌照进行校正，再利用牌照字符的灰度特征，采用基于种子的区域增长方法二值化牌照图像，最后根据车辆牌照的制造标准，提取字符，大量实验证明本文具有很好的结果。     

空间碎片精密测角和测距仿真数据定轨性能分析

目前空间碎片精密跟踪数据可以通过光学测角和激光测距两种手段获取。文中旨在通过大量的仿真实验来分析上述两种手段获取的数据对碎片定轨及预报性能的影响,以期根据各自的特点更好地利用稀缺的数据资源。首先利用了2015年1月Starlette和Larets卫星CPF精密预报轨道作为参考轨道,仿真生成基于国内区域内4个观测站精度1的测角数据和精度1 m的测距数据,然后,利用仿真数据生成单站和双站算例并进行定轨,得到完整弧段及部分弧段的测角、测距数据定轨预报结果。结果表明:在上述观测数据精度基础上,测角数据较测距数据在定轨中的表现更加稳定,将完整通过弧段缩短至90 s时,约75%的角度定轨算例的短期(1~2天)预报轨道仍能够满足20精度要求。实验结果同时表明:单站、双站定轨预报误差分布相似。     

Usability testing a minimal manual for the Intel SatisFAXtionfaxmodem

Two versions of a manual for the Intel SatisFAXtion faxmodem-the original manual shipped with the product and a proposed shortened manual-are compared. It is found using either manual improves performance over using no manual; there is little difference in performance between the group using the original manual and the group using the proposed shortened manual; and documentation cannot completely compensate for inadequacies in the user interface     

Low-crosstalk code-division multiplexed interferometric array

The results obtained using code-division multiplexing with an array of eight sensors are reported. It is demonstrated that crosstalk levels approximately -60 dB can be achieved using this approach using return-to-zero pulse coding.<>     

双向波长上下路光分插复用器

通过对科技文献的归纳总结和分析比较,介绍了四种实现双向波长上下路的光分插复用器结构和工作原理,它们是：（1）基于FBG和多口光环形器;（2）基于波导光栅路由器和FBG;（3）基于阵列波导光栅（AWG）;（4）基于解复用器／复用器对和光开关的OADM结构。     

Sub-0.1 μm NMOS transistors fabricated using laser-plasmapoint-source X-ray lithography

We report the experimental results of the first MOSFET's ever fabricated using a laser plasma-source X-ray stepper. The minimum gate length of these transistors is 0.12 μm with an effective channel length of 0.075 μm. These transistors were patterned using a mix-and-match lithography scheme where the gate level was printed using a 1.4 nm plasma-source X-ray stepper while the other layers were patterned using optical lithography     

Human recognition system for outdoor videos using Hidden Markov model

Human recognition is an essential requirement for human-centric surveillance, activity recognition, gait recognition etc. Inaccurate recognition of humans in such applications may leads to false alarm and unnecessary computation. In the proposed work a robust background modeling algorithm using fuzzy logic is used to detect foreground objects. Three distinct features are extracted from the contours of detected objects. An unique aggregated feature vector is formed using a fuzzy inference system by aggregating three feature vectors. To minimize computation in recognition using Hidden Markov model (HMM), the length of final feature vector is reduced using vector quantization. The proposed method is explained using five basic phases; background modeling and foreground object detection, features extraction, aggregated feature vector calculation, vector quantization, and recognition using Hidden Markov model.     

使用VB快速开发数据库应用系统

介绍了VB6语言编程的特点和开发数据库应用系统的方法及步骤．探讨了VB程序访问后端数据库的．两种途径：数据控件(Data Control)和ADO。     

New CCII and ICCII Based Realizations of L-C and L-R Mutators

New realizations of Chua L-C and L-R mutators using current conveyors (CCII) and inverting current conveyors (CCII) are introduced. Two realizations are available in the literature using CCII for each of the types of L-C and L-R mutators. For the type 1a L-R mutator three new realizations using CCII and ICCII are introduced to complete a family of four realizations. For the type 1b L-R mutator three new realizations using CCII and ICCII are introduced to complete a family of four realizations. For the type 2a L-C mutator fifteen new realizations using CCII and ICCII are introduced to complete a family of sixteen realizations. For the type 2b L-C mutator fifteen new realizations using CCII and ICCII are introduced to complete a family of sixteen realizations. For the type 2c L-C mutator eight new realizations using CCII and ICCII are introduced to complete a family of sixteen realizations. Finally for the types 2a and 2b L-R mutator fifteen new realizations using CCII and ICCII are given for each type to complete a family of sixteen realizations. Although this is a review paper and is partially tutorial it includes many new realizations of L-C and L-R mutators.     

Group III alkyl source purity effect on the quality of GaAs grown with tertiarybutylarsine

We have grown unintentionally doped GaAs films using tertiarybutylarsine (tBAs) or arsine reacted with clean or silicon contaminated triethylgallium. Hall and SIMS data along with photoluminescence spectra show that the silicon contaminant level in GaAs MOCVD layers grown with tBAs is higher than for layers grown using arsine. Thus, high purity in the triethylgallium source is more critical for high purity GaAs films when using tBAs than when using arsine.     

Constant bandwidth current feedback amplifier from two operational amplifiers

In this article, a new constant bandwidth current feedback amplifier is demonstrated using two operational amplifiers and a few components. The circuit is accurate and achieves gains in excess of 20?dB with only a 2.94% change in bandwidth using discrete components in the inverting configuration. The bandwidth can also be accurately defined using two resistors. Experimental results using a dual operational amplifier integrated circuit confirm the measured results.     

Demonstration of fibre impairment compensation using split-step infinite-impulse-response filtering method

Distributed impairment compensation for dispersion and nonlinear effects using backward propagation in a wavelength-division multiplexing (WDM) environment is demonstrated. Dispersion compensation is achieved using complex infinite-impulse-response filtering, which significantly reduces the computational load compared to using finite-impulse-response filtering.     

Performance of single- and double-ring resonators using 3×3optical-fiber coupler

This paper investigates theoretically the transmission characteristics of single- and double-ring resonators using 3×3 optical-fiber couplers. Two configurations of a 3×3 coupler are considered: configuration A, with the three fibers centered at the vertices of an equilateral triangle, and configuration B, with their centers aligned in a straight line. It is found that a ring resonator using configuration A does not show any performance improvement over ring resonators using 2×2 couplers. On the other hand, a single-ring resonator using configuration B has a performance close to resonators using 2×2 couplers. It is also shown that a double-ring resonator using a 3×3 coupler exhibits resonance with a double peak, which may find application in the filtering of coherent frequency-shift keying (FSK) signals after optical amplification in an optical-fiber line repeater     

Design of a Packet-Switched WDM Network with Multi-Wavelength Selectivity

The use of low-speed tunable devices in packet-switched WDM star networks may lead to throughput and delay penalties. We propose (i) a new receiver architecture using multi-wavelength selectivity to eliminate the penalties, and (ii) a corresponding optimal scheduling algorithm for uniform all-to-all transmission. This architecture results in significant cost reduction in comparison with existing pipeline technique. When using a two-wavelength simultaneous selection, our numerical results show that (i) the throughput can increase by 40% in comparison with using a tunable filter alone; (ii) the throughput degradation is 2% in comparison with using two tunable filters in systems using a pipeline technique.