WDM网状网中的基于平面构造的业务量疏导算法

将多个低于一个波长带宽的低速业务流复用到一个波长上传输的业务量疏导已经得到越来越多 的研究。WDM/SDH环网中的业务量疏导已得到大量研究,WDM网状网中的业务流疏导问题研究相对较少。该文研究静态环境下波长数目受限的业务量疏导问题,提出了一种基于平面构造的启发式业务量疏导算法。仿真结果表明该算法比已知的算法具有更好的性能。     

数据通信网综合网管的设计分析

结合TMN电信管理网的体系结构．对数据通信网综合网管的结构和功能进行了分析。     

大功率半导体激光器调制特性的实验研究

设计了一种带有调制输入接口及恒电流、恒功率、恒温控制的光源系统,着重对其低频调制特性进行了实验研究.通过引入负反馈及自动温度控制技术,从外部电路角度改善了半导体激光器的调制输出特性,有效抑制了驰豫振荡,优化了激光二极管(LD)的调制输出参数.     

20kWL波段全固态雷达发射机

介绍了新研制成功的L波段 2 0kW全固态发射机 ,该发射机综合了以前同类固态发射机的优势 ,无论在功率密度、体积尺寸 ,还是可靠性方面都有了新的提高     

带通采样在数据采集中的应用研究

在数据采集中采用带通采样，可大大降低采样率，但系统中的抗混叠滤波器会造成相位的非线性。采用对滤波后的信号进行带通采样，然后再用FRR滤波器校正相位的非线性，从而不失真地还原原信号，最后在Matlab中进行仿真，验证了该方法的有效性。     

Comparison of the copper and gold wire bonding processes for LED packaging

Wire bonding is one of the main processes of the LED packaging which provides electrical interconnection between the LED chip and lead frame. The gold wire bonding process has been widely used in LED packaging industry currently. However, due to the high cost of gold wire, copper wire bonding is a good substitute for the gold wire bonding which can lead to significant cost saving. In this paper, the copper and gold wire bonding processes on the high power LED chip are compared and analyzed with finite element simulation. This modeling work may provide guidelines for the parameter optimization of copper wire bonding process on the high power LED packaging.     

基于STM32的RA8806控制器LCD设计

RA8806点矩阵液晶显示控制器内置字库、触摸屏和键盘接口,具有功能强、移植性强、性价比高的特点,比其他同类产品更受设计人员欢迎。采用RA8806控制器的LCD可以充分满足STM32嵌入式系统的各种液晶显示需求,为了实现这一目的,给出了在STM32上驱动该控制器的方法、触摸屏校准的思路及部分程序,并在实验中得以实现。     

数据库需要专业的安全审计与评估——访清华大学软件学院罗平教授

鉴于近几年数据库遭遇威胁和攻击的事件越来越频繁、越来越严重,使得数据和数据库安全无疑成为当前信息网络安全中一个比较热的焦点话题。由于数据库终端始终是处于“持续加入”中的状态,并且鉴于目前网络安全防护技术的局限性,数据库系统中存在的大量漏洞引起的对数据库攻击不容易被检测和发现,这些都为数据库的安全保障带来了不少难题。前不久也有业内人士提出“树立全民数据安全意识”的理念。     

基于DSP的高速数据采集系统硬件设计

为了满足数据采集及信号处理系统中对数据实时性的要求,采用TMS320VC5509为中心处理器,并对A/D转换、电源及复位电路、时钟电路、JTAG仿真电路等外围硬件进行了设计,使其能够在高速采样信号下,及时对数据进行处理,达到系统对处理速度的要求,实现了一种基于DSP的高速数据采集系统设计。     

Dual-demodulation large-scope high-sensitivity refractive index sensor based on twin-core PCF

In this paper, a refractive index (RI) sensor based on the twin-core photonic crystal fiber (TC-PCF) is presented. Introducing the rectangular array in the core area makes the PCF possible to obtain high birefringence and low confinement loss over the wavelength range from 0.6 μm to 1.7 μm. Therefore, the core region can enhance the interaction between the core mode and the filling material. We studied theoretically the evolution characteristics of the birefringence and operating wavelength corresponding to the strongest polarization point under the condition of filling the rectangular array with RI matching fluid range from 1.33 to 1.41. Simulation results reveal that the proposed TC-PCF has opposite evolutions of change rates between the B and wavelength, and the maximum RI sensing sensitivities of 1.809×10-2 B/RIU and 8 700 nm/RIU at low and high RI infill are obtained respectively, which means that the TC-PCF features of dual-parameter demodulation for the RI sensing can maintain a high refractive index sensing sensitivity within a large scope of RI ranging from 1.33 to 1.41. Compared with the results of single-parameter demodulation, it is an optimized method to improve the sensitivity of low refractive index sensors, which has great application potency in the field of biochemical sensing and detection.