利用动态链接表的二值图像目标区域分割

为了准确、快速地对二值图像中的连通区域进行标识,分割出各个目标物体的位置和面积.提出了一种基于动态链接表的连通区域标记方法.以目标像素线段为基本处理单元,令像素扫描和连通标识同步进行,同时,建立所用连通体的动态链接表,仅需一次扫描便可根据链接关系将图像中所有目标物体分割出来.定义"中空"的4邻域模板.通过特定的判断运算...     

IPTV双模机顶盒终端技术在三网合一领域的应用

IPTV双模机顶盒作为广电双向交互业务开展的用户终端设备,其同时具备DVB-C与IP两种接入系统的方式。主要由软件和硬件两部分组成,整个硬件系统以高性能专用SOC SMP8635L为核心,辅以外围辅助芯片和电路所构成;软件部分则由嵌入式浏览器构成。随着三网融合业务和微电子技术的发展,IPTV机顶盒产品会越来越成熟,功能越来越强大。     

GPS接收机空域和空时滤波性能研究

提出了空域滤波和空时滤波的优缺点,研究了他们的抗干扰性能,并在圆阵中进行了仿真.仿真结果表明这两种方法都可以用于GPS接收机抗干扰.其中,空时滤波结构相对于空域滤波能增加系统的自由度,对于宽带信号能提供更佳的抗干扰性能;价格相对较低的空域滤波结构在普通干扰环境中(干扰数目较少)也是一种合适的选择.     

PWM脉宽调制实现电机的恒速驱动

现在许多单片机具有PWM脉宽调制功能,结合单片机的定时器、计数器,我们可以很方便的实现电机的恒速驱动。本文以编码器为反馈信号,构成了电机恒速转动的闭环系统。     

中远程反舰导弹超视距攻击捕捉特性分析

介绍了中远程反舰导弹超视距射击原理,分析了影响捕捉概率的自控终点系统误差和自控终点随机误差．鉴于现在点射击方式下,影响随机误差的众多因素中,惯导误差、目标指示误差和目标机动误差占主要方面,得出相应的自控终点随机误差近似公式．在此基础上建立了中远程反舰导弹超视距射击捕捉概率模型,并以某型导弹为例,对导弹超视距捕捉特性进行了实例分析．     

RLPG加注系统性能与可靠性一体化设计

通过分析现行武器系统设计中存在的缺点,制定出性能与可靠性一体化设计的工作方案。对RLPG加注系统进行了定性分析,并运用蒙特卡洛法进行了仿真,给出了可靠性设计的控制要点。针对系统的薄弱环节,建立了性能指标和可靠性指标之间的定量关系,进行加注系统及其重要元件性能与可靠性一体化设计。     

光伏建筑一体化部件的热电耦合分析

光伏建筑一体化部件服役过程中组件温度会大幅度升高,使组件中太阳电池的输出特性受到影响导致输出功率下降,直接影响到一体化部件的电性能,因此准确地模拟出组件在服役过程中的温度场分布并计算出此热场下电池的输出功率十分重要。基于等效电路利用隐函数近似解的迭代算法,首先分析不同温度下一体化部件中太阳电池的光电转换效率,然后用有限元分析法模拟部件安装在建筑物屋顶后服役过程中的温度场,再将二者相结合实现部件中单晶硅太阳电池的光电转换效率与工作温度的热电耦合,模拟出部件热电耦合后的温度场,并计算出部件当时的输出功率,为分析光伏建筑一体化部件服役期间的具体热电性能提供理论参考。     

The substituent effect on charge transport property of triisopropylsilylethynyl anthracene derivatives

The charge transport property of two triisopropylsilylethynyl anthracene (TIPSAnt) derivatives TIPSAntBt and TIPSAntNa (bithiophene and naphthalene are introduced at the 2, 6-positions of the TIPSAnt core) were explored through quantum chemical method. To gain a better understanding of the substituent effect on the charge transport property, the results of the parent molecule TIPSAnt was also provided here for comparison. The substituent effect on the molecular geometry, reorganization energy, frontier orbitals, ionization potential (IP) and electronic affinity (EA), crystal property, transfer integrals and charge mobility, band structure and effective mass of the two compounds were investigated to establish the relationship between structures and properties. The introduced bulky TIPS groups made the two compounds adopt two-dimensional, face-to-face, π-stacking structures. The efficient overlaps of π-orbital and smaller π-stacking distance are proved to be the main reason for the high charge mobility of TIPSAntBt and TIPSAntNa. The hole mobilities of TIPSAntBt and TIPSAntNa are 0.88 and 3.60 cm² V⁻¹ s⁻¹, respectively, which is well consistent with experiment values (0.2 and 3.7 cm² V⁻¹ s⁻¹, respectively). For TIPSAntBt, the electron mobility (1.29 cm² V⁻¹ s⁻¹) is a little higher than that of hole due to the more effective transfer integrals of electron. On the contrary, the hole mobility of TIPSAntNa is 20 times larger than that of electron because of the smaller reorganization energy and larger transfer integral of hole, indicating that TIPSAntNa could be used as p-type semiconductor. For TIPSAntBt, the transfer integral is smaller than the reorganization energy, so the hopping mechanism plays a key role in the charge transport property. While the bandwidths and effective mass of TIPSAntNa agreed well with the calculated transfer integrals and charge mobility results. The introduced small substituents to TIPSAnt core contributed to the dramatically different charge transport property from an n-type semiconductor of TIPSAntBt to p-type semiconductor of TIPSAntNa, which shed light on molecular design for an n-type semiconductor through simple chemical structural modification.     

Estiamtion and Correction of Mismatch Errors in Time-Interleaved ADCs

In data acquisition systems, with help of time-interleaved analog-to-digital converter (TIADC) architecture, the maximum sample rate of the whole system can be increased efficiently. However, inevitable offset mismatch, gain mismatch, and timing error between time-interleaved channels degrade the sampling performance. In order to develop the mismatched TIADC structure, this paper first proposes a new time-domain algorithm to estimate the three aforementioned mismatch errors, and then puts forward a calibration method to calibrate the mismatch errors. Finally, numerical simulations are presented to verify the proposed estimation and calibration algorithm.     

Optimization of polymer light emitting devices using TiOx electron transport layers and prism sheets

The internal and external efficiency of polymer light emitting devices were found can be simultaneously improved by insertion a high refractive index material, titanium oxide (TiO_x), to the emission layer and a prism sheet attached to the substrate. The TiO_x layer increased the internal efficiency due to a better electron injection and hole confinement. However, it led a wider angular emission profile with more photons trapped in the substrate. By using the prism sheet, those trapped light was efficiently coupled to the air. The extraction efficiency enhancement was increased from 33.1% to 54.4% and the overall current efficiency was improved up to 86%.