联机计费数据采集系统及其应用

本主要介绍了采用联机计费数据采集系统的必要性，以及该系统所能提供的功能，然后介绍了在黑龙江省实施联机计费的方案。     

利用温度和植被指数进行地物分类和土壤水分反演

首先利用地物表面温度和植被指数，成功地对北京精准农业示范区内生长旺盛小麦、稀疏小麦、池塘水体、水草、淤泥和裸露土壤等6种地物进行了分类，其次，利用地物表现温度（LST）和归一化植被指数（NDVI）作为坐标系，建立LST－NDVI三角形分布的散点图，分析了散点图的地物特征分布及其物理意义，与植被的红外和近红外两个特征波段构造的散射图相比，同类样本的离散度更小，不同类别样本之间的距离更大。最后，提出了植被指数－－表面温度的土壤水分反演模型，结合地面采样数据成功地反演了实验区内作物地块的土壤水分。     

Data hiding approach for efficient image indexing

A data hiding approach to embed the indexing keys inside the JPEG compressed images for their retrieval, inspired from the spirit of digital watermarking, is proposed. At the stage of database population, the existing approach is to compress all images by standard JPEG in order to save their storage space, but this ignores the compression of their indexing keys under the notion that the size of each indexing key is negligible. When a large image database is established, however, this part of storage space becomes non-trivial. By hiding the indexing keys inside the JPEG compressed codes, significant advantages are gained in that the indexing keys can be compressed naturally by JPEG without any additional cost. Experiments on hiding an indexing key of 256 bytes illustrate that: no noticeable distortion is introduced in comparison with non-watermarked images; and their storage space is reduced into the region of 7-27% of their original size.     

可穿戴设备归属权限转换协议研究

针对可穿戴环境下的信息安面临的巨大挑战,本文在考虑公共环境下可穿戴设备的用户转换的情景下,设计了一个适合可穿戴环境的用户权限转换协议框架,并对协议进行了详细设计.通过理论和实践分析得出,该协议可以满足可穿戴设备对安全性和实用性的要求,可以保障转换过程中的数据安全.     

船舶电气接地故障的安全性分析

本文从船舶电气接地故障的特点出发,对船舶电气发生接地故障的原因进行了分析,同时也探讨了两种船舶电气接地故障的查找方法,并提出了几点船舶电气接地故障的处理方法,旨在提高船舶电气设备的安全性,保证船舶的可靠运行.     

CMOS／SEED光电子集成Crossbar互连网络的实现及控制

本文报道了光电子集成 Crossbar互连网络的光学实现及电控制方法。采用带光窗口的 CMOS/SEED灵巧像元列阵作为逻辑控制交换开关节点 ,输出光强的高低态对比度约为 1.4。由波长为 85 0 nm的半导体激光器发出的光束经过位相计算全息光栅分束器分束 ,形成 8× 2的光束阵列 ,为 CMOS/SEED光调制器窗口列阵提供泵浦光源 ,采用精密加工的高精度二维光纤阵列作为信号输入、输出接口器件。采用计算机并口产生电控制信号实现网络的交叉连接功能 ,编制了相应的控制软件。实验上完成了 16× 16 Crossbar光互连网络的交换功能     

ELECTRON GUN FOR LARGE ORBIT GYROTRON (LOG) WITH DECREASED INFLUENCE OF CATHODE PLASMA ON ELECTRON BEAM PROPERTIES

High power Large Orbit Gyrotron (LOG) [1] is now under development at FIR FU. First version of this device was recently manufactured and then assembled with power supply ETIGO-IV [2]. Results of preliminary tests of electron-optic system are presented. The conditions when stable flat form of current pulse realized are discussed. Analytical estimations of cathode-anode distance to achieve small influence of cathode plasma during high voltage (HV) pulse are performed. Two new electron gun versions with decreased influence of the cathode plasma on its impedance and pulse form are suggested and optimized. New optimal magnetic field distributions are found. First gun has quiasi-flat cathode configuration near the anode diaphragm and provides operating current about 60 A. Second one uses blade cathode with operating current about 30 A. Beam quality for both guns is suitable for LOG operation.     

谈采样频率在实践中的应用

大家知道,采样频率是数字音频技术中的一个重要概念．它表示模数转换时每秒钟抽取样值的个数。采样频率越高．其模拟原值的精度越高．保真度也就越高。当然．采样频率越高,AD转换时所需空间越大,硬件的投入也就越高。因此．只有在条件允许的情况下．采样频率越高越好。     

用脉冲激光饱和荧光法测定铀原子光吸收截面

本文介绍了用脉冲激光饱和荧光法，来测定铀的０－１６９００ｃｍ＾－１能级的吸收截面，讲述了测量光吸收截面的基本原理，实验测量过程，并用此方法测量铀原子光吸收截面和国外文献发表相吻合。     

几种无线本地环路系统的性能分析

本地无线环路是用户接入网的一种形式,它可对终端用户提供数据业务和话音业务。本文介绍了无线环路中的几种主要技术DECT、PWT-E、PACS,分析了其系统结构、数据性能、频谱容量等性能,并对其实用性进行了比较。