"软硬分离",数字电视条件接收系统的必然趋势

本文介绍了数字电视条件接收系统的基本原理,分析了当前纯硬件的条件接收系统面临着安全问题和推广难的问题。“软硬分离,机卡分离”的条件接收系统解决了数字电视的管理安全性和数字电视推广成本高的问题。得出结论,“软硬分离,机卡分离”的条件接收系统发展的必然趋势。     

数字电视广播条件接收系统检测环境和方法设计

数字电视广播条件接收系统是数字电视运营中最重要和关键的系统之一,本文结合《数字电视广播条件接收系统技术要求和测量方法》中对数字电视广播条件接收系统的要求,针对数字电视广播条件接收系统的检测环境和检测方法进行了设计说明.     

数字电视的条件接收系统

数字电视的兴起使人们能够欣赏到高质量的电视节目,伴随数字电视的成熟,条件接收系统(CAS)得到很好的发展.主要介绍数字电视条件接收系统相关技术的发展、基本功能、安全机制、工作原理及其安全性要求.     

基于FPGA数字电视CA系统加密算法的实现

随着科学技术的发展,数字电视成为现代电视系统的主流.数字电视的关键是条件接收系统,条件接收系统中的关键性技术是要有加密技术的支持,加密技术关系到整个数字电视网络的安全性.而数字电视条件接收系统的核心问题是对加扰控制字的加密.为了确保电视信号安全有效的传输,加密技术是当下研究的热点之一.因此以下主要介绍基于FPGA数字电视条件接收系统中DES加密算法的实现,最后的仿真结果论证了该算法实现方案在条件接收系统中的可行性.     

数字电视的条件接收系统

数字电视的兴起使人们能够欣赏到高质量的电视节目，伴随数字电视的成熟，条件接收系统（CAS）得到很好的发展。主要介绍数字电视条件接收系统相关技术的发展、基本功能、安全机制、工作原理及其安全性要求。     

数字电视中的条件接收系统

数字电视指将传统的模拟信号转化为数字进行处理、传输和接收的系统.数字电视的条件接收系统运用各种数字技术通过对节目的加扰处理,使只有授权用户才能收看被加扰节目,从而保障运营商的利益,保证数字电视发展.本文主要阐述当前数字电视使用的条件接收系统的基本原理,以及实际中应用两种条件接收方式的设计和实现,并比较两种方式的优势和不足.最后介绍当前国内数字电视发展的现状.     

桂林市有条件接收数字电视前端CA系统原理

桂林市有条件接收数字电视系统采用算通公司集成的数字条件接收系统，其设计策略是：以数字条件接收为核心发展实用的收费数字电视系统、数据广播系统、以及视频点播系统(VOD)。     

数字电视的条件接收系统原理与应用

数字电视指将传统的模拟信号转化为数字进行处理、传输和接收的系统。数字电视的条件接收系统运用各种数字技术通过对节目的加扰处理，使只有授权用户才能收看被加扰节目，从而保障运营商的利益，保证数字电视发展。 本文主要闻述当前前数字电视使用的条件接收系统的基本原理，以及实际中应用两种条件接收方式的设计和实现，并比较两种方式的优势和不足。最后介绍当前国内数字电视发展的现状。     

也谈数字电视条件接收系统

条件接收系统是数字电视系统中重要的组成部分。条件接收系统可根据用户不同的需要,对数宇电视广播业务按时间、频道和节目进行管理控制,是数字电视收费的技术保障系统。本文对数字电视条件接收系统原理和功能进行了论述。     

数字电视条件接收系统的研究

数字电视条件接收系统通过对节目进行加扰处理,使只有授权用户并且已经付费的用户才有权接收加扰后节目,从而能够保证运营商的根本利益,也就保证了数字电视技术的正常发展。在分析数字电视发展的基础上,对DVB的条件接收系统的工作原理和加密算法作了详细的分析研究。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.