一种播出系统的扩展设计

在目前播出系统设备的数字化改造中,在节目播出方面通常采用格非硬盘播出系统,结合设备系统运行的实际情况,针对原有硬盘播出系统中存在的一些不足之处,通过软件开发和硬件集成相结合的方法,对播出系统进行了扩展设计,并从硬盘播出备播系统、节目插播系统、播出节目上载站点、播出节目素材同步系统、播出节目素材复制系统、播出节目审片系统等方面进行了完善.     

丰县电视台播出系统数字化改造

纵观电视播出发展历程,随着播出技术的进步、设备的更新、频道的增多以及节目、广告和字幕等信息量的加大,节目的播出方式和播出形式也随之逐步改变,播出系统内部的结构和流程也发生了转变.自动播控系统发展到今天,经历过几次重大变革.第一代播出系统解决了从手动播出到自动播出的自动化问题;第二代播出系统解决了从磁带播出到硬盘播出的文件化问题;第三代播出系统解决了编播系统网络化及与外部系统间的互通问题;第四代播出系统解决了播出系统融入全台网问题.     

加强广告播出管理保障安全播出的几点设计思路

结合黑龙江电视台播出系统在实现广告播出、广告倒计时的实际经验,从如何加强广告播出,确保播出安全角度出发,结合广告播出特点,给出了播出系统实现广告播出、广告倒计的几点设计思路。重点分析了如何从节目单、反馈信息和控制信息三个维度,实现播出系统与字幕或者频道包装系统信息同步,确保广告播出和广告倒计时播出的安全、便捷、准确、可靠。     

淮安广播电视台数字播出系统优势数字播出新方式

电视播出系统不断发展主要历经手动磁带播出、自动磁带播出、硬盘磁带播出、全硬盘播出等阶段。播出系统由单频道工作站播出向多频道服务器播出、模拟系统播出向数字系统播出逐渐转换。安全播出是电视台的生命保障,播出系统的稳定可靠性尤为重要,是众多电视台选购硬盘播出系统首要考虑的主要因素。     

电视台播出系统的安全维护措施探讨

播出系统是电视台节目系统的重要组成。经过近年来的发展,电视台播出系统逐渐由传统的实时磁带播出升级为以硬盘播出为主、录像机播出为辅的综合性播出系统。但是,随着电视台播出系统的高清化改造以及无人值守播出系统的开发与应用,硬盘播出系统在安全性方面暴露出一定的问题,需要借助完善的维护措施加以控制,以保障节目播出的质量和可靠性。基于此,文章在概括介绍电视台播出系统的基础上,就播出系统运行中容易出现的安全问题以及系统安全维护的具体措施进行探讨研究,为电视台播出系统的运行维护提供相关技术方法参考。     

播出服务器异地上载系统应用实践

为了提高播出系统的可靠性和安全性、简便性,切实加强技术防范,保障电视节目的安全优质播出,进一步完善全数字播出系统,江阴电视台引进了播出服务器异地上载系统.阐述播出服务器异地上载系统的构成和特点,以及系统的设置和调试.     

吉林电视台高清字幕播出系统

在线字幕播出系统（二维与三维）在电视播出方面得到了广泛的应用,在实际应用过程中我们发现了三维在线字幕系统更具有优势,三维字幕系统与节目播出系统更相匹配,该系统能更好的实现播出要求。本文着重的介绍了三维在线包装播出字幕系统在吉林电视台播出工作中的优势,分别是系统的稳定性、播出的效果、播出操作的快捷性和网络架构的四个方面。     

硬盘播出系统的维护和管理

随着广播电视数字化进程的推进,计算机性能、稳定性的提高及硬件成本的降低,计算机硬盘播出系统逐渐在播出中脱颖而出,取代了磁带播出,提高了播出系统的效率和安全性.硬盘播出系统包括编单、制作、上载、播出等诸多子系统,硬盘播出系统的运行维护和管理需要多部门协同,因此,要站在全局的高度进一步统一思想、分工协作,才能确保整个系统的安全稳定.     

硬盘自动播出系统的应用及维护

随着计算机技术的高速发展,电视播出系统也逐步得到提升,由以前的手动播出、半自动播出提升到现在的硬盘自动播出。硬盘自动播出系统是将模拟信号采集到计算机硬盘中,或将DVD、VCD光碟中的内容直接拷贝到硬盘中,然后用自动播出软件编排节目播出表,最终由播出卡输出音视频信号。硬盘自动播出系统主要由视频服务器、节目上载、审片硬盘服务器、播出硬盘服务器、垫片播出硬盘服务器以及预监系统和数据库服务器等组成。     

广东电视台高清播出系统改造项目的设计与实现

为拓展播出规模,广东电视台播出中心对原有的高清播出系统进行了系统改造.从视音频系统、播出控制系统、视频服务器系统等方面分别详细描述了新的高清播出系统架构与设计思路,举例介绍了新系统的特点及为提高播出安全性所采用的特别技术设计,使得新系统具有较强的技术先进性、可扩展性和可兼容性.     

Graphene‐Based Nanomaterials: Synthesis,Properties, and Optical and Optoelectronic Applications

Graphene, a two‐dimensional, single‐atom‐thick carbon crystal arranged in a honeycomb lattice, shows extraordinary electronic, mechanical, thermal, optical, and optoelectronic properties, and has great potential in next‐generation electronics, optics, and optoelectronics. Graphene and graphene‐based nanomaterials have witnessed a very fast development of both fundamental and practical aspects in optics and optoelectronics since 2008. In this Feature Article, the synthesis techniques and main electronic and optical properties of graphene‐based nanomaterials are introduced with a comprehensive view. Recent progress of graphene‐based nanomaterials in optical and optoelectronic applications is then reviewed, including transparent conductive electrodes, photodetectors and phototransistors, photovoltaics and light emitting devices, saturable absorbers for ultrafast lasers, and biological and photocatalytic applications. In the final section, perspectives are given and future challenges in optical and optoelectronic applications of graphene‐based nanomaterials are addressed.     

高速光纤综合通信网络平台研究

现代通信网络应能满足各种通信业务和通信容量日益发展的需求,实现话音、数据、视频、IP等业务的一体化综合交换和传输。在比较TDM、IP和ATM三种协议的基础上,提出"采用内置RPR和MPLS功能的MSTP平台"建设光纤综合通信网络平台的实现方法。MSTP采用SDH的数据帧结构,保持了SDH标准光接口、灵活分插低速信号、自愈环保护和功能强大的网管等优点,可对TDM、IP和ATM协议进行优化传输。     

Wireless IP and Its Challenges for the Heterogeneous Environment

The tremendous momentum toward building a mobile wireless Internet using the Internet Protocol (IP) has thrust many challenges upon the technology developers and the operators. These challenges encompass the 2.5G, 3G, and future solutions and standards. Some of the key issues deal with supporting IP traffic across different wireless and MAC protocols, end-to-end QoS and mobility, traffic engineering and scalability, protection/restoration, operations and management, authentication/privacy/security, billing, and content and context aware networking. This article addresses the drivers, the issues, and solutions (wherever possible) in the above areas, and concludes with a summarization of the challenges that lie ahead.     

卫星遥感温室气体的大气观测技术进展

全球、区域及城市的碳浓度、碳源汇信息是应对气候变化、达成双碳目标、完善国际谈判、支持治理政策制定与执行的重要依据。国际认可的“自上而下” 方法将卫星观测作为基础的通量计算技术, 是验证温室气体排放清单的重要手段。系统介绍了温室气体的卫星探测载荷原理、类别和发展, 以及反演、估算CO2、CH4 和N2O 的浓度和排放通量的方法, 还有探测缺失和误差存在的影响因素等; 分析了对卫星探测温室气体能力提高的迫切需求, 浓度反演和排放量估算精度不足, 以及N2O、氟化物等其他温室气体遥感研究缺乏、地基遥感验证能力薄弱等问题; 最后总结了我国温室气体卫星遥感技术的发展趋势, 主要是面向主被动高时空分辨率卫星的研制应用、高精度多尺度排放量估算(特别针对城市、小区域和点源尺度)、氟化物遥感评估等主题, 以加强对碳排放的量化观测, 并增强对碳循环的理解, 提高感知和应对气候变化的能力。     

卫星通信组呼业务MAC层研究

组呼通信在指挥调度中有着重要作用,而在一些地面没有基站的地方,就无法正常使用。卫星通信具有无视地形,通信范围广,不易受陆地灾害影响,易于建设等优点。把卫星通信和组呼通信结合在一起的卫星组呼通信技术兼顾两者的优点,能更好的发挥指挥调度这一作用。当前卫星组呼通信采用固定频率方式,组呼成员在一个频率下进行通信,这种方式实用性不好。本文研究的是移动卫星组呼,在GMR-1系统的基础上研究了卫星组呼通信中MAC层的功能,提出了MAC-Ready-Gcc、MAC-Dedicated-Gcc这两个为了支持组呼的状态,并针对在MAC层发生的PTT竞争提出了一种回退策略。     

机动6m抛物面天线车结构总体方案探讨

文章遵循策划、分解、综合及优化的总体方案研究思路,根据要求,提出了三个机动6 m抛物面天线车结构总体备选方案;针对系统结构组成,详细分析了天馈线、天线座、拖车以及系统标定等子系统所有可能的结构方案;最后综合权衡研究三个备选方案在技术、质量、成本、周期等多方面的优劣,选择了最佳结构总体方案,确保了所选方案具有合理性、可行性、经济性、先进性和科学性。实践证明,所选方案用户满意,实施效果良好。     

Alternative Schemes for Dynamic Secure VPN Deployment in UMTS

Three alternative schemes for secure Virtual Private Network (VPN) deployment over the Universal Mobile Telecommunication System (UMTS) are proposed and analyzed. The proposed schemes enable a mobile node to voluntarily establish an IPsec-based secure channel to a private network. The alternative schemes differ in the location where the IPsec functionality is placed within the UMTS network architecture (mobile node, access network, and UMTS network border), depending on the employed security model, and whether data in transit are ever in clear-text, or available to be tapped by outsiders. The provided levels of privacy in the deployed VPN schemes, as well as the employed authentication models are examined. An analysis in terms of cost, complexity, and performance overhead that each method imposes to the underlying network architecture, as well as to the mobile devices is presented. The level of system reliability and scalability in granting security services is presented. The VPN management, usability, and trusted relations, as well as their behavior when a mobile user moves are analyzed. The use of special applications that require access to encapsulated data traffic is explored. Finally, an overall comparison of the proposed schemes from the security and operation point of view summarizes their relative performance. Christos Xenakis received his B.Sc. degree in computer science in 1993 and his M.Sc. degree in telecommunication and computer networks in 1996, both from the Department of Informatics and Telecommunications, University of Athens, Greece. In 2004 he received his Ph.D. from the University of Athens (Department of Informatics and Telecommunications). From 1998–2000 was with the Greek telecoms system development firm Teletel S.A., where was involved in the design and development of advanced telecommunications subsystems for ISDN, ATM, GSM, and GPRS. Since 1996 he has been a member of the Communication Networks Laboratory of the University of Athens. He has participated in numerous projects realized in the context of EU Programs (ACTS, ESPRIT, IST). His research interests are in the field of mobile/wireless networks, security and distributed network management. He is the author of over 15 papers in the above areas. Lazaros Merakos received the Diploma in electrical and mechanical engineering from the National Technical University of Athens, Greece, in 1978, and the M.S. and Ph.D. degrees in electrical engineering from the State University of New York, Buffalo, in 1981 and 1984, respectively. From 1983 to 1986, he was on the faculty of Electrical Engineering and Computer Science at the University of Connecticut, Storrs. From 1986 to 1994 he was on the faculty of the Electrical and Computer Engineering Department at Northeastern University, Boston, MA. During the period 1993–1994 he served as Director of the Communications and Digital Processing Research Center at Northeastern University. During the summers of 1990 and 1991, he was a Visiting Scientist at the IBM T. J. Watson Research Center, Yorktown Heights, NY. In 1994, he joined the faculty of the University of Athens, Athens, Greece, where he is presently a Professor in the Department of Informatics and Telecommunications, and Director of the Communication Networks Laboratory (UoA-CNL) and the Networks Operations and Management Center. His research interests are in the design and performance analysis of broadband networks, and wireless/mobile communication systems and services. He has authored more than 150 papers in the above areas. Since 1995, he is leading the research activities of UoA-CNL in the area of mobile communications, in the framework of the Advanced Communication Technologies & Services (ACTS) and Information Society Technologies (IST) programmes funded by the European Union (projects RAINBOW, Magic WAND, WINE, MOBIVAS, POLOS, ANWIRE). He is chairman of the board of the Greek Universities Network, the Greek Schools Network, and member of the board of the Greek Research Network. In 1994, he received the Guanella Award for the Best Paper presented at the International Zurich Seminar on Mobile Communications.     

MATLAB在地理信息系统开发中的应用

GIS是计算机科学、地理学、测绘学、地图学等多门科学综合的技术,其核心是计算机科学,基本技术是数据库、地图可视化及空间分析。MATLAB是当前流行应用软件和编程语言,它集数学计算、可视化和编程于一体,易学易用。本文介绍了MATLAB软件的主要特点,阐述了MATLAB地图工具箱、数据库工具箱、用户图形界面及其与外部程序的接口等技术,并探讨了它们在地理信息系统开发中的应用。     

基于声卡的虚拟示波器设计

随着现代科学和信息技术的不断进步,示波器作为一种电子测量处理仪器也在不断发展并且已经变的越来越精密,也越来越智能.传统的模拟示波器受到低频响应能力和带宽限制等多方面因素影响在很多领域已显得力不从心,虚拟示波器的出现很好的解决了这些问题.本文以LabVIEW18版本为开发平台,设计制作了一款基于声卡的虚拟示波器.重点介绍...     

The effect of soldering process variables on the microstructure and mechanical properties of eutectic Sn-Ag/Cu solder joints

Fundamental understanding of the relationship among process, microstructure, and mechanical properties is essential to solder alloy design, soldering process development, and joint reliability prediction and optimization. This research focused on the process-structure-property relationship in eutectic Sn-Ag/Cu solder joints. As a Pb-free alternative, eutectic Sn-Ag solder offers enhanced mechanical properties, good wettability on Cu and Cu alloys, and the potential for a broader range of application compared to eutectic Sn-Pb solder. The relationship between soldering process parameters (soldering temperature, reflow time, and cooling rate) and joint microstructure was studied systemati-cally. Microhardness, tensile shear strength, and shear creep strength were measured and the relationship between the joint microstructures and mechani-cal properties was determined. Based on these results, low soldering tempera-tures, fast cooling rates, and short reflow times are suggested for producing joints with the best shear strength, ductility, and creep resistance.