数据压缩编码器中Z扫描电路的设计与仿真

对数据压缩编码器中的z扫描电路的功能和在整个编码器中的任务进行了分析,在此基础上,设计出了Z扫描电路的总体结构,并进行了仿真,最后根据输出波形验证了设计的正确性.     

自适应预置零技术的研究

自适应技术能够动态地适应变化的环境和变化的系统要求,这个特点使其被广泛地用于地震、通讯、声纳、导航、自控、生物医学和雷达等领域。本文通过分析自适应直线阵的工作特点,提出了一种新的技术,用于克服在低角目标跟踪过程中的多路径效应,这种技术具有简单易行,实时性好等特点。     

同源连杆机构构成特性和传动角的研究

从理论上揭示了原始机构及其同源机构在尺寸型上的内在联系,即它们的确生成了同一条轨迹.还提出,同源机构与原始机构的对应构件有相同的角速度;在通常使用情况下,同源四杆机构与原始四杆机构具有相同的传动角.     

色散补偿技术在通信传输系统中的应用

本文介绍了色散补偿现象对光信号在传输过程中的影响,并结合中国网通长途传输网工程,提出了解决色散问题的具体措施及建议.     

8～12μm波段折/反/衍混合坦克扫描物镜消热差设计

根据坦克扫描光学系统的要求,设计了一种工作于8～12μm波段,可识别2 000 m远坦克目标的折/反/衍射混合红外消热差光学系统。该系统采用新型的卡塞格林系统,其非球面主镜和次镜全部取代为球面,解决了卡塞格林系统大口径非球面主镜、次镜的高加工精度和装调难的问题;通过应用衍射元件独特的温度特性实现红外光学系统的无热化设计,设计的系统结构简单紧凑,口径大、焦距长、分辨率高,并且在-40～60℃的温度范围内成像质量接近衍射极限,满足坦克扫描系统的总体要求和像质要求。     

The working mechanism of organic photovoltaic cell by using copper phthalocyanine as exciton blocking layer

We demonstrate the working mechanism of organic photovoltaic (OPV) cell with copper phthalocyanine (CuPc) as exciton blocking layer (EBL). The new EBL material CuPc, commonly has been used as electron donor in the organic solar cells due to its electron-donating and hole-transporting properties. But here we proves that the α-polymorph CuPc layer can transfer electrons to Al cathode through the half-filled b_1g level, this mechanism is different from that of general EBL material with larger band gap and electron-transporting property, which is based on damage states induced by the heat of evaporating Al.     

便携式峰值功率分析仪核心设计

介绍了峰值功率分析仪的基本结构、主要模块的设计以及实现,论述了微波信号处理、信号峰值检波、信号采样和数据处理、测频以及频响误差补偿技术与校准、系统软件实现原理.提出了一种便携式峰值功率分析仪的设计方案.按照该方案设计的便携式峰值功率分析仪实现了对射频信号功率的准确快速测量.     

在线网络数学教学平台的应用分析

在线网络平台是数学教学的重要辅助手段.在线网络平台在数学教学中的应用一方面推动了数学教学水平的提高;另一方面则可以帮助学生养成利用网络数学平台进行数学学习的习惯.随着现代网络技术的快速普及,越来越多学校建立了网络数学平台,并在数学教学中发挥着积极作用.     

Proactive multipath routing with a predictive mechanism in software‐defined networks

With the growth of network traffic volume, link congestion cannot be avoided efficiently with conventional routing protocols. By utilizing the single shortest‐path routing algorithm from link state advertisement information, standard routing protocols lack of global awareness and are difficult to be modified in a traditional network environment. Recently, software‐defined network (SDN) provided innovative architecture for researchers to program their own network protocols. With SDN, we can divert heavy traffic to multiple paths in order to resolve link congestion. Furthermore, certain network traffics come in periodic fashion such as peak hours at working days so that we can leverage forecasting for resource management to improve its performance. In this paper, we propose a proactive multipath routing with a predictive mechanism (PMRP) to achieve high‐performance congestion resolution. PMRP has two main concepts: (a) a proactive mechanism where PMRP deploys M/M/1 queue and traffic statistics to simulate weighted delay for possible combinations of multipaths placement of all subnet pairs, and leverage genetic algorithm for accelerating selection of optimized solution, and (b) a predictive mechanism whereby PMRP uses exponential smoothing for demand traffic volumes and variance predictions. Experimental results show a 49% reduction in average delay as compared with single shortest routing, and a 16% reduction in average delay compared with utilization & topology‐aware multipath routing (UTAMP). With the predictive mechanism, PMRP can decrease an additional 20% average delay. Furthermore, PMRP reduces 93% of flow table usage on average as compared with UTAMP.