HFC网络安全性研究与改进

阐述了HFC网络结构特点并指出其安全问题,在分析DOCSIS的BPI和BPI 安全规范的基础上加入了PGP技术,并提出了在HFC网中改善保护网络通信安全的实现方案,指出并分析了仍然存在的问题.     

HFC网络安全与加密机制的研究

增强型基线保密性接口（BPI＋）是一种基于DOCSIS标准的数据保密访问共享媒体的接口标准,利用BPI＋定义的多种密钥及管理协议可以在媒体访问控制层（MAC）解决HFC网络的数据安全问题。这种技术对开展HFC网络数据业务是十分重要的。     

基于DOCSIS的HFC网络数据传输安全性简析

本文简要介绍了有线电视宽带网络结构及DOCSIS BPI 协议,从协议层说明了有线电视网络(HFC)做数据传输的安全原理。通过DOCSIS BPI 协议在CMTS与Cable Modem之间对传输数据及协议进行加密,从而做到防止业务的盗接、窃听等,提供高质量的服务。     

基于DOCSIS标准的HFC数据加密算法的分析

基于DOCSIS标准的增强型基线保密性接口（BPI＋）采用56bit DES加密分组数据，采用二密钥三重DES加密通信量加密密钥。这种多重加密技术的应用为HFC网络的数据传输提供了相当于或更好于专线级的网络安全与加密性能。     

顺德区HFC双向网络改造

根据对顺德区有线电视HFC双向网络改造和建设的实践。分析HFC双向网络改造和建设的一些关键问题。探讨HFC双向网络改造建设如何解决汇聚干扰、汇聚均衡和通道安全三大技术难题；探讨在工程施工当中的规范要求和注意事项。讨论中小城市如何建设适合、规范、可靠的有线电视HFC双向网络。     

双向HFC网络上行通道维护方式探讨

交互业务在双向HFC网络上的大量开展对有线电视网络的管理和维护提出了更高的要求，其中上行通道的维护是HFC网络维护的重点和难点，分析网络管理中上行通道维护的方法和缺点，提出利用HFC网络设备管理系统、HFC网络频谱分析系统和Cable Modem系统，通过有效的数据分析有针对性地进行网络维护以提高维护效率的方法。     

HFC综合业务网的网络管理系统的研究和应用

1引言 随着有线电视的发展，HFC网的建设得到了飞速发展，由于HFC网的宽带特性、丰富的频率资源、方便的接入手段和相对较低的费用，网络运营商（各地广电网络公司）非常希望将它用来综合信息的传输和多种增值业务的开展。另外，近两年一系列的线路盗用和入侵也给HFC网络的安全提出了更高的要求。然而，目前HFC网络的可靠性远远达不到综合信息传输和增值业务发展的要求，同时其安全问题也急需解决。为此，就必须对HFC网进行有效的监控和管理。也有许多文章在探讨和呼吁网络管理系统的作用和建设。但是现在HFC网络的监控和管理基本上处于一个无序的状态。设备管理现状不是很乐观，很多网络公司对此没有给予充分的重视，也没有进行必要的投资。双向网的建设和网络管理系统的建设没有同步进行。究其原因，有下述几条。     

HFC网络及其IP数据传输的方法讨论

本文对现有HFC网络模型、相关标准和协议及网络服务进行了分析，指出了目前HFC网络系统存在的问题。对合理选择适当的HFC网络模型来规划设计HFC网络系统有一定的意义。     

有线电视双向HFC网络设计探讨

有线电视HFC双向网络和传统的单向网络相比，在设计和施工调试方面都有一些特殊性问题。因此在设计HFC网络的时候，必须对下行通道和上行通道结合考虑，以满足双向传输的要求。本文分析了双向HFC网络设计的三大关键要素，着重对上行通道的网络结构、噪声分析、抑制噪声的措施及双向电缆分配网络的设计进行了探讨。     

HFC网络的双向改造

对HFC网络现状进行分析，针对中小城市双向HFC网络改造所选用的设备及设备技术参数进行论述，对双向HFC网络改造中所遇到的问题加以阐述，并结合许昌HFC网络的实际改造案例，对HFC网络改造中反向通道的调试作系统分析。     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.