通信专业英语.ppt

Specialized English on Telecommunication,Unit 18 Multimedia,Key terms:transmission that combine media of communication(text and graphics and sound etc.)Multimediaa user interface based on graphics(icons and pictures and menus)instead of text;uses a mouse as well as a keyboard as an input device GUI Graphics User Interface图形用户接口 CD-I Compact disc interactive 交互式紧凑光盘系统 JPEG Joint photographic experts group MPEG Moving picture experts group,MIDI Musical Instrument Data Interface乐器数字接口 Bitmap位图SVG Scalable Vector Graphics 可缩放的矢量图形GIFGraphics Interchange Format图形交换格式RGB 三原色模式CMYK 印刷色彩模式(cyan青，magenta品红，yellow黄，black黑)Hypertext超文本,computer software that recognizes numbers and letters of the alphabet which are written on paper,so that information from paper documents can be scanned into a computer OCR optical character recognition光学字符识别 MDBMS Multimedia database management system 多媒体数据库管理系统 Pervasive扩大的，渗透的Whimsical 古怪的，反复无常的Pin钉住Nuance微小的差别（色彩等）,Perspective透视，角度，远景Convey运输，传递，转换Counterpart伙伴，副本，对应物Artifact人工制品Video-clip录像剪辑Audio recording唱片Juxtapose并置，并列Innovative创新的，富有革命精神的,Ingredient成分，要素Synthetic合成的，综合性的Extract抽取，分离indicator consisting of a movable spot of light(an icon)on a visual display;moving it allows the user to point to commands or screen positions Cursor光标，游标，指针Annotate给.注解DQDBDistributed queue dual bus分布式队列双总线Deploy采用，推广应用,Predominance优势，显著Precursor先驱，前任Voicegrade音频级Computer mediated communications计算机中介通信an event or situation that happens at the same time as or in connection with another Accompaniment伴随物，附属物Consensus意见一致VODVideo-on-demand视频点播,Deadline截止时间Constrain限制，约束Deviate偏离Preference选择，喜欢Dominant主要的，控制的By contrast相反，对比起来Pass on 传递，切换,Lena image(512*512)Bmp 24bit 769kJPG 41kGIF 138kTIFF 897 PNG 672Bmp monochrome 33k,Passage B Characteristics,Multimedia is one the most innovative ways of using a telecommunications network to achieve effective communications(1)between people and(2)for access to information.多媒体是在（1）人与人之间（2）获取信息中，用通信网络获得有效的通信的最重大的变革方式This chapter describes the essential ingredients of multimedia and gives a wide variety of examples of applications in a wide range of industrial settings.这章描述了多媒体的基本组成，并且给出了在广泛工业环境中应用的许多例子。,Four key ingredients四个关键组成Multimedia communication is defined here as the combination of four key ingredients:多媒体通信被定义为下面四个方面的组合Two or more of the five media of communication(audio,data,fax,image,and video);具有通信的五种媒体中2个或者2个以上的媒体。Interactive capabilities between the communication parties;通信方之间的交互能力Communications with human users.人类用户参与的通信,Multimedia systems involve communications with human users as senders or receivers of information,or both.多媒体系统涉及到参与通信的人作为发信者或者收信者或者两者都是。By contrast,single medium systems,such as data and fax,can involve inter-machine communications with no human user present while the communication is underway.对比而言，单一媒体系统，例如，在通信过程中，数据，传真，涉及到机器之间的通信，但没人参与。,It is the human element that benefits from more than one medium of communication,and also from the interactive capabilities of multimedia systems.从人的角度来看，是受益于多种媒体的通信的，也受益于多媒体系统之间的交互能力。Synchronization.Multimedia systems require two types of synchronization between the different media.同步性，多媒体系统需要不同媒体之间通信具有两种类型的同步。,Continuous synchronization is required for audio/video,for instance,to coordinate lip movement with speech.在视频和音频中要求连续性同步，例如，演讲时对嘴唇的协调控制。Synthetic synchronization is required by the designer of the system to organize the presentation of material in the desires manner(e.g.,the sequencing of video clips with data and graphics).在设计的系统中各元素按照自己想要的方式出现必须采用综合同步。例如，具有数据和图像的视频剪辑的顺序。,Videoconferencing is a typical example of multimedia,combining two media(audio and video),interaction,human users,and synchronization.视频会议是多媒体的一个典型例子，包含两个媒体，音频和视频，交互，人，同步系统。By contrast,broadcast television allows no backward channel for the information receiver to interact with the information provider,and it is therefore not regarded as a multimedia communication.对比而言，广播电视容许没有用于信息接收者与信息发送者进行交互的反向通道，因此不能认为是多媒体通信。,The types of interaction in multimedia systems are as follows:多媒体系统中交互类型包括下面几种：Search and browse.These correspond to database access functions for extracting the required multimedia information from storage.搜寻和浏览。这些是同从存储媒体中获得需要的多媒体信息的相应的数据库接入功能相对应。,Interactive“buttons”.A frame of information(i.e.,a screen or portion of a screen)may contain buttons that can be selected(e.g.,using a cursor)to control the presentation of information,and to pass on to another frame.交互按钮。帧信息可能包括被选择的按钮，这个按钮用来控制提供的信息和传递给另外一个帧。Examples of“buttons”are lists of options,menu selections,and portions of the displayed information that can be selected to obtain additional information on that subject.例如按钮可以是选项，菜单选择，和在被选择的目标上显示出附加信息,Windowing.One frame of information overlaps a background frame,and the size of frames can be changed by the user so as to view portions of several frames simultaneously.窗口技术，一个帧的信息同背景帧交叠，为了能同时看到几个帧信息，帧的尺寸能被用户改变。Fast forward,rewind,pause,and skip.“tape recorder”commands to control the sequence and speed of presentation of information can be used,not just with audio and video information but also to control a sequence of frames of data,fax,and image.快进，回倒，暂停和跳过。使用控制被使用信息的展示速度和顺序的磁带录音机的功能键，不仅可以控制音频和视频，还有数据，传真和图像帧的顺序。,Conversational interaction.When a human user is present at each end of the communication channel,a wide range of conversational interactions are possible,including audio discussion,displaying data and images in shared screens,and pointing to,editing and annotating the contents of the shared screen.会话交互。当人们出现在每个通信信道末端，很大范围的会话交互是可能的，包括音频讨论，数据和图像显示的屏幕共享，和对共享屏幕的定位，编辑和评注。,Enabling technologies支撑技术Multimedia communication has come about as a result of the development of a number of technological capabilities.由于大多数技术能力的发展，多媒体通信已经发生了变化。These capabilities are described in the following subsections.下面的部分中将对这些技术能力进行描述Fast-packet networks.The high bandwidth,burst nature of multimedia communications makes it particularly suited to fast-packet telecommunication capabilities such as those provided by ATM and DQDB.快速分组网络。高带宽，多媒体通信爆发式发展的特性使得诸如ATM和DQDB等快速分组网络特别适合于它们。,Until these networks are widely deployed,multimedia communications can be based on circuit capabilities at a range of bandwidths and lower bandwidth packet capabilities.Such as X.25 and frame relays.在这些网络广泛使用以前，多媒体通信可建立在一定带宽范围的电路和较低带宽的分组功能的基础上，例如X。25和帧中继。High capacity storage systems.The predominance of storage intensive media,such as audio,video,and high resolution image in multimedia communications requires high capacity storage systems,such as optical disks.高容量存储系统。密集型存储煤质的优势，例如音频、视频和高分辨率图像在多媒体通信中都需要高容量存储系统，例如光碟。,Powerful processing capability.The encoding/decoding of a variety of media plus the synchronization of their presentation to the user require powerful processors.强有力的处理能力。不同媒体的编码和解码，加上将它们展示给用户时的同步要求都需要强有力的处理器。Compression coding.The development of coding techniques for audio,image,and video has enabled multimedia communications to be compressed into available bandwidth.压缩编码。音频，图像，视频编码技术的发展已经使得多媒体通信能被压缩在有限的带宽内。This enabled many multimedia systems to be developed before the availability of broadband networks.Broadband communications results in improved quality and lower end-to-end delay.这些技术使得在宽带网络可用之前，许多多媒体系统可用。宽带通信导致了通信质量的改善和端对端延时的减少。,Hypertext.Hypertext is a precursor to multimedia that was developed several years before the technology necessary for multimedia becoming available today.超文本。超文本是多媒体的先驱，在多媒体所需技术发展之前，超文本已经使用多年了。Windowing.Windowing software gives an interface in which the user can interact with several files or software processes using a single screen.窗口化。窗口软件提供了一个用户能在一个屏幕对几个文件和软件进程进行交互的界面。,It was originally developed in a single medium situation-namely,image-and was rapidly extended to cater for motion video.它最初在单一媒体中发展起来的，如图像，并且迅速的扩展到了可以适用于移动视频。It greatly enhances the interactive capabilities of many multimedia systems today.今天，许多多媒体系统的交互能力已经给大大的增强了。,Business advantages of multimedia communications多媒体通信在商业中的优势。There is a strong latent demand for multimedia communications as evidenced by:商业中对多媒体通信存在强烈的潜在需求，证据如下：The use of videoconferencing to display a technical drawing or other object of discussion as well as the head and shoulders of the discussant.视频会议的使用可以显示绘画技术和其他的讨论对象以及参加讨论者的头和肩膀。,This is essentially the use of motion video to provide a still-image capability.用移动视频来提供静止的图像的是一个基本的能力。The use of fax and data communication equipment during the course of a videoconferencing;在视频会议期间使用传真和数字设备。The use of modems that allow voice and data communications over one voice-grade line.调制解调器的使用容许声音和数据通信都在音频级线路上完成。,These examples imply a demand for interactive combinations of all five communications media:audio,data,image,fax,and video.这些例子暗示了对5种通信媒体：声音，数据，图像，传真和视频的复合交互的需求。The business effectiveness of multimedia communications can be estimated from the effectiveness of earlier forms of computer mediated communications(CMC)in which users of CMC,and research into its benefits,is more established than for multimedia since it has been used since the mid-1970s.由于从70年代中期计算机中介通信已经被使用，因此多媒体通信在商业中的效用比多媒体本身更加明确，这可以从早期的计算机中介通信中的用户中得到评估，并且可以研究多媒体通信的好处。,The effectiveness of CMC has been analyzed in business group decision-making situations and in educational settings as an instructional tool.计算机中介通信的效用在商业团体决策中已经被分析，并且在教育环境中已经成为一个有用的工具。Group decision making 团体决策Studies have shown the there are advantages to CMC in group decision-making situations compared to face-to-face meetings.许多研究已经显示了计算机中介通信在团体决策中比面对面会议中的优势。,Table 6.1 gives a comparison between computer-mediated communications and face-to-face meetings.表6.1给出了计算机中介通信和面对面会议的比较情况。The result in table.6.1 can be summarized by the statement that computer mediation allows for(1)more opinions to be given by more group members and(2)willingness to change opinion in order to come to a quality decision.表6.1结果中总结和比较如下：（1）计算机通信能容许更多的团体成员发表更多的意见。（2）为了获得高质量 的结论，参与人员能更加自由积极的改变意见。,Fact-to-face meetings can result in poorer decisions,resulting from the bandwagon effect of dominant personalities.面对面的会议形式将导致较差的决议，主要是因为由占有主导的人决定的流行效应。These advantages of CMC can be expected to apply with greater force in the case of multimedia communications,where the computer-mediated element has more impact on the human senses than in the data/text-based situations.由于计算机中介系统对于人的理性影响比数据、文本为基础的方式要大得多，因此，计算机中介系统的优势必将在多媒体通信中得到极大的发挥。,Education教育AT&T researchers conducted a comparison between audio-graphic and face-to-face instruction in a controlled text with two groups of students.AT&T 研究者对音频图像和面对面形式之间，在一个可控内容的教育中的对两组学生进行了比较。Pre-test scores showed an insignificant difference between the two groups,but post-test scores showed that the group trained using audio-graphics had higher scores than the face-to-face group.预测试成绩显示：两组学生不具有明显差别，但是后测试成绩就有明显的差别了，采用音频图像的那组成绩会比面对面教育那组更高。,The use of audio/image systems for distance learning at George brown college resulted in good student acceptance of the system with an unexpected side benefit:two-hour classroom sessions extended to three hours simply because the students did not need travel home after class.在乔治布朗学院的远程教育中采用音频和图像系统导致了好的学生在接受这个系统时产生了其他的效果：因为学生不需要下课后回家，所以两个小时的课程扩展到了3个小时。Multimedia can stimulate the interest of school children in educational material.多媒体能激励受教育学生的兴趣。In an inner city school in texas with a 60-70%failure rate,the use of a multimedia instructional system reduced the failure rate to 22%.在得克萨斯州的中心城市学校有60-70%的考试不及格率，当使用多媒体教育系统后，不及格率降低到了22%.,