icip论文模板
icip论文模板
在我国经济组成中,汽车产业对促进国民经济发展和社会进步具有重要的战略意义。下面是我为大家精心推荐的关于汽车的科技3000字论文,希望能对大家有所帮助。
汽车的科技3000字论文篇一:《试谈汽车超载监测系统》
摘 要: 为了实时识别各种车型的超载车辆,该系统基于开源计算机视觉库(OpenCV),先根据车辆照片库建立车型分类器,然后使用数字摄像机拍摄进入监控区域的车辆,在视频中使用分类器识别车型,根据所识别得到的车型去查询数据库获得该车型的核载,再通过动态称重技术获得车辆的实际载重,及时判别车辆是否超载。此 方法 可避免过去使用统一重量衡量不同车型是否超载的弊端,并可同时免线圈测量车速。测试结果表明系统能快速准确地识别出车型。配合动态称重系统,就能实时得出所通过的车辆是否超载,对公路养护和道路交通安全有相当大的实用意义。
关键词: 超载监测; 视频识别; OpenCV; 动态称重
超载车辆的危害很大,主要表现在加速道路损坏和危害道路交通安全,人们都深知其危害性,所以治理超载一直是公路监管部门的工作重点。传统的自动超载信息系统都是使用统一标准,对所有车辆都应用同一个整车重量划分是否超载,这样会遗漏部分实际上已经超过该车型核载的超载车辆。实际上,这部分车辆对道路交通同样造成严重影响。鉴于此,本系统首先识别出车辆的车型,再查询得到该车型的核载重量,对比实测重量,便得知是否超载。理论上能够适用于所有车型。
利用摄像机较长的视域,附加设计了一个测速系统,能方便地得出超速数据,以便作为超速监测和供给动态称重系统作参考。
1 系统构成
1.1 系统方案
系统主要工作过程为:车辆驶入摄像机监视范围,视频流通过以太网传输到后台处理系统,处理系统通过处理视频识别出车辆的车型,然后根据车型从数据库中查出相应的核载重量;同时,安装在地面的动态称重设备测出车辆的实际载重。两个数据对比即可得出车辆是否超载。系统流程如图1所示。
为了加快处理速率,在程序设计过程中多处使用了多线程并行处理。
1.2 OpenCV及其分类器介绍
传统的图像处理软件大多为Matlab,用于开发算法最为快捷,但是其处理速度慢,难以跟上视频处理的需求,所以选用了Intel牵头开发的开源计算机视觉库(OpenCV)。新版的OpenCV已经在易用性上已经接近Matlab,再加上其开源性,很多算法均已公开,加快了开发进程。另外,目前OpenCV已经提供C,C++,Python等语言接口,且支持Windows,Linux,Android和IOS等主流平台,资源相当丰富。对于计算机平台,OpenCV支持多线程并行计算和图形处理器(GPU)计算,这将能大大加快计算速率,用其开发本系统的demo是首选。
图1 系统流程图
为了从视频流中识别出车型,需要使用分类器[1]。所谓分类器,是利用样本的特征进行训练,得到一个级联分类器。分类器训练完成后,就可以应用于目标检测。分类器的级联是指最终的分类器是有几个简单分类器级联组成。每个特定的分类器所使用的特征用形状、感兴趣区域中的位置以及比例系数来定义(如图2所示)。
图2 特征分类
首先使用弱分类器分出货车和客车等车型,然后再分出大中小型货车,最后再精确分类,获得准确的车型。新版本的OpenCV已经支持多种特征的分类器,如SVM,LBP,PBM等。因为系统实时性要求较高,这里选取训练和分类速率都较高的LBP特征分类器。
1.3 训练分类器
使用分类器的需要首先训练,即让分类器“认识”目标,为了训练分类器,需要准备样本,样本包括正样本和负样本。正样本即包含目标的灰度图片,而且每张图片都要归一化大小,负样本则不要求归一化,只需要比正样本大即可(使得可以在负样本中滑动窗口检索)。
OpenCV提供了专门的工具用以整理训练样本的原始数据,只需准备好正、负样本,归一化然后转成灰度图,再使用两个描述文件分别记录这些样本集合,然后输入程序即可整理出原始数据。为了准备正样本,借助OpenCV提供的HighGUI模块,在此专门编写了一个GUI截图工具,界面如图3所示。为了能从不同角度识别车辆,准本正样本时需要准备从一定角度范围描述车辆的样本。
图3 GUI截图工具界面
接下来就是训练分类器,这部分工作直接关系到系统的鲁棒性。同样,OpenCV提供了专门工具训练分类器,既有旧版也有新版,为了有更多特性,在此选择新版本的训练程序。
由于这是基于统计的方法,要对大量数据进行处理,如果选择Haar特性,训练周期会比较长,不利于系统的搭建,所以选择用LBP特性训练分类器。从机器性能方面考虑训练时间,使用英特尔线程构建模块(TBB)重新编译OpenCV,就能得到多核加速,且有利于接下来的程序性能。分类器分为三级,分别为:货车、客车分类器,大、中、小型货车分类器和具体车型分类器。由于客车按载客数区分是否超载,车辆总重不会对公路造成严重损坏,所以本系统无需对客车作出具体车型区分。但若然具体管理部门需要统计车型信息,可以进一步加上客车车型分类器。实际使用时,由于要应对车辆车身的喷漆变化或者小范围合法改装等情况,分类器的分类除了在系统筹建的时候大规模训练外,在系统运行时也应继续训练分类器,增加统计数据,使得识别结果更加精确。
1.4 识别车型及获得核定载重
训练好分类器后,最直观的测试方法是直接输入测试视频,检查识别效果。新版本OpenCV提供一个C++类CascadeClassifier,该类封装了基本的目标识别操作,使得只需要使用该类的实例加载训练好的XML文件,然后逐帧检测即可。若发现目标,结果将会存放在C++标准模板库(STL)容器vector中。但直接对每帧图像使用CascadeClassifier::detectMultiScale方法将会大大加重系统的工作量并且在多车辆的情况下无法区分开各车辆,为此,首先需要发现车辆,然后区分不同的车辆目标,再对每一个目标单独进行分类识别。
具体的主要操作的顺序为:
(1) 系列的图像预处理操作,降低图像噪音。
(2) 图像差分,发现车辆轮廓[2],得到运动掩码。图像差分有两种主要方式,分别是帧间差分和背景差分。帧间差分速度快,但容易产生空洞,且无法分离出缓慢运动的车辆;背景差分速度慢,但分离效果好。考虑到如果车辆是缓慢进入测速区,则称重数据可靠性高,而且没有超速,进入识别点的效果好,所以选择帧间差分,这里使用能有效减小前景空洞的三帧差分算法[2]。
(3) 结合运动掩码更新历史运动图像、计算历史运动图像的梯度。
(4) 分割运动目标,得到一辆一辆的车,并跟踪。为区分开图像中的每一辆车,需要对其进行标记,这里使用的方法为:
[Mkx,y=ID ifMk-1x,y≠0&k-1≠10 ifMk-1x,y=0 ]
式中:Mk(x,y)为分割出来的单独车辆目标的第k帧感兴趣区域矩形。这种方法虽然鲁棒性较好,但是因为重复计算量大,运算速度有限,所以在确定每辆车的ID后,使用OpenCV提供的更为快速的Camshift算法[3]继续跟踪。
(5) 计算每辆车的运动方向。这部分关系到运动目标筛选,在部分场合,摄像机的视野可能会涉及逆向车道。在这种情况下,可以通过筛选符合主要行驶方向的车辆来排除其他车辆或无关运动目标的干扰。
(6) 车辆进入测速区,开始测速。
(7) 车辆离开测速区,结束测速并计算速度。使用TBB进行并行分类识别车型。由于OpenCV新版矩阵结构Mat的所有操作使用原子操作,大大减轻了多线程编程的工作量,所以这里使用多线程并行操作是最佳选择。
(8) 根据所安装动态称重系统的车速要求,判断是否需要引导车辆到检测站进行检查。
1.5 获得实际载重
在视频分析中发现车辆后,对比动态测重模块中测得的实际载重。这里需要把应用场合分为两种情况:高速测重和低速测重,至于高低速的阀值,这根据不同动态称重系统的性能而定[4],在系统安装时根据动态称重系统参数设置即可。由于目前高速测重技术的精度未达到作为证据的要求,所以在高速测重的场合,所得车重数据只能作为初步判断,若初步发现车辆超载,需要进一步引导车辆到大型地磅再次静态测量,并作其他处理。在低速测重场合,测得的动态数据可靠,可直接作为证据使用。所以系统的运行需要测速模块的配合。 无论高速场合与低速场合,本系统都能实现视频测速功能,可以直接用作超速抓拍系统,降低了公路部门的重复投入成本。
1.6 测速方法
测速测量车辆通过测速区所用的时间,然后用测速区长度除以时间而粗略估计得到。考虑到摄像机视域限制,设定的测速区域并不长,只有20 m左右,而且速度是用于参考载重信息是否有效的,所以无需太精确,因而可认为车辆是直线经过测速区域的。测速区的长度需在系统安装时手工进行长度映射。另外,确定通过测速区域的时间差使用帧率和帧计数得出,这样在多线程处理的情况下,可以排除系统时钟和处理速率的干扰,得出准确时间差。
2 测量结果
为快速测试系统性能,直接使用测试视频替代摄像机输入。使用微软Visual Studio 2010 MFC + OpenCV 2.44 编写一个即时处理程序,界面如图4所示。
图4 运行在Windows平台上的系统
测试使用一台Intel Core i5M处理器(主频2.3 GHz+智能变频技术)、6 GB内存、 操作系统 为Windows 7 64 b的普通 笔记本 计算机,测试代码尚未使用图形处理器(GPU)计算,但代码在识别部分应用了TBB进行多核并行加速计算。
测试视频共两段,分别在两个不同的场景拍摄,第一段只有一辆公交车,场景较为简单;第二段则是多车多人环境,并且有车辆并行的情况,场景较为复杂,干扰较多。
第一段视频主要用于测试系统的极限性能,在测试开始前,先用转码工具把同一段视频转成不同帧率和分辨率的几段视频,其中视频的宽高比不变。输入视频测试后的结果如表1所示。
视频原始长度为6 s,双斜线为该场景的称重和测速区域。
测试结果表明:系统能实时处理标清视频流,但对高清视频还需进一步优化。
第二段视频主要测试系统的车型识别能力,测试数据如图5所示。
表1 输入视频测试后结果
图5 多车并行时能够准确区分
第二段视频夹杂较多无关目标,如行人、抖动的树枝横向行驶的车辆等,其中双白线之间区域为本场景的称重测速区域。
通过测试,可以看出无关目标能被全部排除,体现了车辆筛选很好的鲁棒性。视频中共通过9辆汽车,所有车辆均本正确识别车型。
3 结 语
通过测试数据可以看出,本系统提出的车型识别算法能适应不同场景和一定的环境变化,具有较高的效率和鲁棒性。随着计算机及其他数字信号处理(DSP)设备的信息处理能力不断提高,应用实时视频处理技术促进智能交通的能力将更大更稳定。若本系统能真正应用在智能交通系统上,有望对遏制道路超载超速现象做出贡献。
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汽车的科技3000字论文篇二:《试谈现代科技在汽车焊接工艺中的应用》
摘 要:随着我国汽车保有量的不断增加,汽车售后市场呈现了井喷式的发展趋势,与汽车相关的售后市场服务行业开始兴起。其中汽车维修是后市场比较火爆的行业,汽车的使用必然会涉及汽车的维修。因此,为了能够更好的实现汽车维修效率,提高汽车维修的质量,应该加强对于汽车维修行业的行业监管以及对汽车维修技术的提升。目前,诸多的现代化技术开始不断的应用到汽车维修之中,其中尤其以焊接工艺为主。因此,本文重点对汽车焊接工艺中现代科技的应用进行分析,从而探讨其未来的发展趋势。
关键词:现代科技;汽车;焊接技术;工艺
引言
汽车加工与制造以及汽车维修领域,都会涉及汽车的焊接技术。目前,随着技术的不断发展,尤其是汽车生产制造业的蓬勃发展,已经可以实现汽车车身以及车辆配件的无缝焊接技术。车身的加工甚至采用模具化加工的形式,从而减少了因为焊接造成的不足。因此,目前,焊接工艺在汽车后市场应用比较广泛,尤其是在汽车的维修市场中,当汽车出现事故的时候,就会采用焊接技术进行维修,从而让汽车能够保证正常的使用。此外,在汽车的加装方面,焊接技术更加的适用,并且通过引进先进的现代科技,从而让焊接效果与质量都更加完善。
一、汽车焊接工艺的应用领域分析
在汽车领域中,由于越来越多的高新技术被应用,是的汽车生活更加丰富。对于我国而言,随着汽车保有量的不断增加,汽车售后市场出现了井喷的状态。在汽车售后市场中,汽车的维修与保养占据着非常重要的地位,也让汽车的服务产业有了较大的发展。对于汽车的焊接工艺而言,最早是应用于汽车的车身焊接。但是,随着技术的发展以及车身制造工艺的发展,汽车车身开始使用模具制作,从而降低了因为焊接而造成的车身问题。那么,下面就对现代化的汽车的焊接工艺主要应用领域进行分析:
1、在汽车的维修领域中有非常广泛的应用;汽车维修属于汽车售后市场领域,由于汽车驾驶的过程中,难免会出现碰撞的现象,从而造成了汽车车身或者是相关配件的损坏。因此,在这种情况下,就可以使用汽车的焊接工艺,将损坏的部分采用焊接的方式,从而进行汽车的维修工艺。
2、人们对于汽车的装饰和改装越来越感兴趣。虽然在汽车检测的过程中,对于擅自改装会进行处罚,但是有车一族们仍然热衷于对于汽车的改装和装饰。其中,对于汽车尾翼的安装非常常见。汽车安装尾翼以后,就显得非常运动动感,有一种非常霸气的感觉。因此,为了让汽车的外观更加个性鲜明,需要对汽车的外观进行相关的改装,从而实现车主所需要的效果。而对于尾翼的加装而言,就一定要采用焊接技术,从而使得汽车的尾翼牢固坚实。因为安装尾翼还是存在一定的风险的,当车速达到一定程度的时候,就需要保证汽车的尾翼的稳定性。
3、对于汽车的车身配件的焊接工艺;汽车在使用的过程中,经常需要在配件方面进行焊接,此外对于在配件之间的结合方面,也需要在适当的情况下使用汽车焊接技术。因此,对于汽车的焊接工艺而言,主要在车身焊接、汽车改装以及汽车配件之间主要进行应用。
二、现代科技在汽车焊接工艺中的应用
随着现代科技的不断发展,汽车焊接工艺中也不断的引入了现代的科技技术。其中最为重要的就是计算机技术,计算机的单片机远程通信技术以及3Dmax等技术开焊接始不断应用到汽车的焊接工艺中。由于人工焊接技术容易在焊接的过程中出现失误,无法实现循迹操作,从而造成焊接的不完美。因此,采用计算机单片机技术,可以进行程序编译,将需要焊接的部分利用3Dma x的进 行仿真,从而保证在焊接的过程中,其能够实现完美的循迹焊接,降低了焊接过程中出现的失误。
此外,在焊接的工艺方面,又引入了一些工艺以及化工技术。传统的高温焊接技术,不仅仅容易造成伤害,更是对操作人员有一定的影响。因此,使用现在的氩弧焊焊接技术,虽然温度更高,但是焊接的质量有所提高。对于焊接的接口以及焊面的平整度,都有了显著的提高。因此,随着现代科技的不断发展,促进了多个行业工艺的提升。对于汽车的焊接工艺而言,引入计算机技术并且实现真正的智能化以及自动化焊接,从而让焊接工艺更加安全方便,有效的提升焊接的效率,保证在焊接的过程中,达到质量的提升以及客户的满意提升。总之,要充分适应时代的发展,让更多的现代科技不断的应用到汽车的焊接工艺之中,从而保证其在不断的发展过程中,符合现有时代的发展理念,满足客户不断提升的硬性要求,实现现代化的汽车焊接工艺。
三、机器人焊接工艺是现代汽车焊接技术的发展前景
汽车焊接最主要的是车身的焊接。在汽车制造公司车身的主要焊接方法为弧焊、点焊、二氧化碳保护焊等。随着社会的发展,人民生活水平的提高,用户个性化需求的日益强烈,对汽车的安全性、美观性与舒适性的要求越来越高,同时汽车制造企业为了追求更大的经济效益,对焊接精度、焊接质量和焊接速度等的要求越来越高,因此建立一条现代化的生产流水线就显得非常重要。而焊接机器人的应用促进了现代化流水线的建立。现代化的焊接流水线主要是满足多车型、多批次的市场需求,提高车身车间生产能力的柔性和弹性。因此现代焊接线必须具有柔性。那么如何才能使焊接线具有柔性呢?普通的焊接线是刚性的,主要由焊接夹具、悬挂点焊机、弧焊机和多点焊机等组成。
这种焊接线一般只能焊接一种车型的车身,那么为了满足市场多元化的需求,就需要重新建立焊接流水线。这对企业来说是非常不利的,企业是追求利润为目的的,并且重新建立流水线造成了财力、人力、物力的浪费。于是建立柔性化焊接生产线摆在了企业面前。机器人的出现与应用满足了汽车企业的现代化的需求,实现了焊接生产线的柔性化。那么在车身焊接线上应用的机器人主要有几种:点焊机器人、弧焊机器人和激光焊机器人。这些机器人的应用,使焊接实现了机器人代替工人工作。
1、点焊机器人:主要进行的是点焊作业,在点与点之间移位时速度比较快,从而减少了移位的时间,通过平稳的动作、长时间的重复工作和准确的定位,取代了笨重、单调、重复的体力劳动,更好地保证了焊点质量,使工作效率得到了很大的提高。它是柔性自动生产系统的重要组成部分,增强了企业应变能力。
2、弧焊机器人:弧焊过程比点焊过程要复杂得多,对焊丝端头的运动轨迹、焊枪姿态、焊接参数都要求精确控制。具有较高的抗干扰能力和高的可靠性。能实现连续轨迹控制,并可以利用直线插补和圆弧插补功能焊接由直线及圆弧所组成的空间焊缝,还应具备不同摆动样式的软件功能,供编程时选用,以便作摆动焊,而且摆动在每一周期中的停顿点处,机器人也应自动停止向前运动,以满足工艺要求。此外,还应有接触寻位、自动寻找焊缝起点位置、电弧跟踪及自动再引弧功能等。
3、激光焊接机器人:激光焊接是与传统焊接本质不同的一种焊接方法,是将两块钢板的分子进行了重新组合,使两块钢板融为了一体变为一块钢板,从而提升了车身结构强度。同时在焊接过程中焊接工件变形非常小,一点连接间隙都没有,焊接深度/宽度比高,焊接质量高。从而提升了车身的结合精度。可见机器人的应用,实现了焊接流水线的智能化,实现了焊接生产线的自动化与现代化。
结束语
汽车维修行业中的汽车焊接行业,其技术要求相对较高,并且直接影响着汽车的维修效果。焊接技术,一般是针对出现重大事故或者是问题车辆等进行焊接。为了让焊接的痕迹最小化,实际上就是为了能够更好的实现高精度焊接,需要不断引入现代科技技术。计算机技术的引入,让焊接工艺能够以一种循迹的方式进行,从而避免了焊接过程中出现的认为失误。此外,在汽车的生产以及制造的过程中,依然需要不断的引入高新科学技术,让焊接工艺更加精湛,从而实现汽车的高精度和高密度,实现汽车质量的全面提升。
参考文献
[1]刘鸣斌.煤层气发动机爆震的检测与控制[J].内燃机与动力装置,2011(02):45-46.
[2]吴扬帆.汽油发动机爆震分析与控制[J].传动技术,2010(13):36-38.
[3]高玉明.点燃式发动机临界爆震控制及其特性[J].吉林大学学报,2012(14):77-79.
>>>下一页更多精彩的“汽
icip什么水平
这个应该是受整个领域的发展和会议的组织者没有与时俱进的影响。
_CPR不清楚,ICIP现在整体论文质量确实不高,但在国外还是有一批做传统image processing的大佬投稿和参会的。可能是因为这帮大佬们早就功成名就,Fellow加身了,然后因为各种原因没太跟进新的AI大潮,就我认识的大佬,比如ICIP创办人Alan Bovik组基本就一直在投ICIP,从来不投CVPR。
_易约旱际ο_AAI,IJCAI, ACM MM这些A会都不让投,但是ICIP还是让投的,当然主要还是投CVPR。IJCAI (1+): AI最好的综合性会议, 1969年开始, 每两年开一次, 奇数年开. 因为AI 实在太大, 所以虽然每届基本上能录100多篇(现在已经到200多篇了),但分到每个 领域就没几篇了,象achine learning、computer vision这么大的领域每次大概也 就10篇左右, 所以难度很大.
_还勇加寐噬侠纯吹共惶?,基本上20%左右, 因为内 行人都会掂掂分量, 没希望的就别浪费reviewer的时间了. 最近中国大陆投往国际会 议的文章象潮水一样, 而且因为国内很少有能自己把关的研究组, 所以很多会议都在 complain说中国的低质量文章严重妨碍了PC的工作效率. 在这种情况下, 估计这几年 国际会议的录用率都会降下去. 另外, 以前的IJCAI是没有poster的, 03年开始, 为了 减少被误杀的好人, 增加了2页纸的poster.值得一提的是, IJCAI是由貌似一个公司 的”IJCAI Inc.”主办的(当然实际上并不是公司
?, 实际上是个基金会), 每次会议上要 发几个奖, 其中最重要的两个是IJCAI Research Excellence Award 和 Computer & Thoughts Award, 前者是终身成就奖, 每次一个人, 基本上是AI的最高奖(有趣的是, 以AI为主业拿图灵奖的6位中, 有2位还没得到这个奖), 后者是奖给35岁以下的 青年科学家, 每次一个人. 这两个奖的获奖演说是每次IJCAI的一个重头戏.另外, IJCAI 的 PC member 相当于其他会议的area chair, 权力很大, 因为是由PC member 去找 reviewer 来审, 而不象一般会议的PC member其实就是 reviewer. 为了制约 这种权力, IJCAI的审稿程序是每篇文章分配2位PC member, primary PC member去找 3位reviewer, second PC member 找一位.
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关于互联网的英语论文,带有中文翻译。3000字左右。急啊。
华文版本
The Internet is a worldwide, publicly accessible series of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government networks, which together carry various information and services, such as electronic mail, online chat, file transfer, and the interlinked web pages and other resources of the World Wide Web (WWW).
History
Creation
The USSR's launch of Sputnik spurred the United States to create the Advanced Research Projects Agency, known as ARPA, in February 1958 to regain a technological lead.[1][2] ARPA created the Information Processing Technology Office (IPTO) to further the research of the Semi Automatic Ground Environment (SAGE) program, which had networked country-wide radar systems together for the first time. J. C. R. Licklider was selected to head the IPTO, and saw universal networking as a potential unifying human revolution.
Licklider moved from the Psycho-Acoustic Laboratory at Harvard University to MIT in 1950, after becoming interested in information technology. At MIT, he served on a committee that established Lincoln Laboratory and worked on the SAGE project. In 1957 he became a Vice President at BBN, where he bought the first production PDP-1 computer and conducted the first public demonstration of time-sharing.
At the IPTO, Licklider recruited Lawrence Roberts to head a project to implement a network, and Roberts based the technology on the work of Paul Baran,[citation needed] who had written an exhaustive study for the U.S. Air Force that recommended packet switching (as opposed to circuit switching) to make a network highly robust and survivable. After much work, the first two nodes of what would become the ARPANET were interconnected between UCLA and SRI International in Menlo Park, California, on October 29, 1969. The ARPANET was one of the "eve" networks of today's Internet. Following on from the demonstration that packet switching worked on the ARPANET, the British Post Office, Telenet, DATAPAC and TRANSPAC collaborated to create the first international packet-switched network service. In the UK, this was referred to as the International Packet Stream Service (IPSS), in 1978. The collection of X.25-based networks grew from Europe and the US to cover Canada, Hong Kong and Australia by 1981. The X.25 packet switching standard was developed in the CCITT (now called ITU-T) around 1976. X.25 was independent of the TCP/IP protocols that arose from the experimental work of DARPA on the ARPANET, Packet Radio Net and Packet Satellite Net during the same time period. Vinton Cerf and Robert Kahn developed the first description of the TCP protocols during 1973 and published a paper on the subject in May 1974. Use of the term "Internet" to describe a single global TCP/IP network originated in December 1974 with the publication of RFC 675, the first full specification of TCP that was written by Vinton Cerf, Yogen Dalal and Carl Sunshine, then at Stanford University. During the next nine years, work proceeded to refine the protocols and to implement them on a wide range of operating systems.
The first TCP/IP-wide area network was made operational by January 1, 1983 when all hosts on the ARPANET were switched over from the older NCP protocols to TCP/IP. In 1985, the United States' National Science Foundation (NSF) commissioned the construction of a university 56 kilobit/second network backbone using computers called "fuzzballs" by their inventor, David L. Mills. The following year, NSF sponsored the development of a higher-speed 1.5 megabit/second backbone that became the NSFNet. A key decision to use the DARPA TCP/IP protocols was made by Dennis Jennings, then in charge of the Supercomputer program at NSF.
The opening of the network to commercial interests began in 1988. The US Federal Networking Council approved the interconnection of the NSFNET to the commercial MCI Mail system in that year and the link was made in the summer of 1989. Other commercial electronic e-mail services were soon connected, including OnTyme, Telemail and Compuserve. In that same year, three commercial Internet Service Providers were created: UUNET, PSINET and CERFNET. Important, separate networks that offered gateways into, then later merged with, the Internet include Usenet and BITNET. Various other commercial and educational networks, such as Telenet, Tymnet, Compuserve and JANET were interconnected with the growing Internet. Telenet (later called Sprintnet) was a large privately funded national computer network with free dial-up access in cities throughout the U.S. that had been in operation since the 1970s. This network was eventually interconnected with the others in the 1980s as the TCP/IP protocol became increasingly popular. The ability of TCP/IP to work over virtually any pre-existing communication networks allowed for a great ease of growth, although the rapid growth of the Internet was due primarily to the availability of commercial routers from companies such as Cisco Systems, Proteon and Juniper, the availability of commercial Ethernet equipment for local-area networking and the widespread implementation of TCP/IP on the UNIX operating system.
Common uses of the Internet
E-mail
For more details on this topic, see E-mail.
The concept of sending electronic text messages between parties in a way analogous to mailing letters or memos predates the creation of the Internet. Even today it can be important to distinguish between Internet and internal e-mail systems. Internet e-mail may travel and be stored unencrypted on many other networks and machines out of both the sender's and the recipient's control. During this time it is quite possible for the content to be read and even tampered with by third parties, if anyone considers it important enough. Purely internal or intranet mail systems, where the information never leaves the corporate or organization's network, are much more secure, although in any organization there will be IT and other personnel whose job may involve monitoring, and occasionally accessing, the e-mail of other employees not addressed to them.
The World Wide Web
Many people use the terms Internet and World Wide Web (or just the Web) interchangeably, but, as discussed above, the two terms are not synonymous.
The World Wide Web is a huge set of interlinked documents, images and other resources, linked by hyperlinks and URLs. These hyperlinks and URLs allow the web servers and other machines that store originals, and cached copies, of these resources to deliver them as required using HTTP (Hypertext Transfer Protocol). HTTP is only one of the communication protocols used on the Internet.
Web services also use HTTP to allow software systems to communicate in order to share and exchange business logic and data.
Software products that can access the resources of the Web are correctly termed user agents. In normal use, web browsers, such as Internet Explorer and Firefox, access web pages and allow users to navigate from one to another via hyperlinks. Web documents may contain almost any combination of computer data including graphics, sounds, text, video, multimedia and interactive content including games, office applications and scientific demonstrations.
Through keyword-driven Internet research using search engines like Yahoo! and Google, millions of people worldwide have easy, instant access to a vast and diverse amount of online information. Compared to encyclopedias and traditional libraries, the World Wide Web has enabled a sudden and extreme decentralization of information and data.
Using the Web, it is also easier than ever before for individuals and organisations to publish ideas and information to an extremely large audience. Anyone can find ways to publish a web page or build a website for very little initial cost. Publishing and maintaining large, professional websites full of attractive, diverse and up-to-date information is still a difficult and expensive proposition, however.
Many individuals and some companies and groups use "web logs" or blogs, which are largely used as easily updatable online diaries. Some commercial organisations encourage staff to fill them with advice on their areas of specialization in the hope that visitors will be impressed by the expert knowledge and free information, and be attracted to the corporation as a result. One example of this practice is Microsoft, whose product developers publish their personal blogs in order to pique the public's interest in their work.
Collections of personal web pages published by large service providers remain popular, and have become increasingly sophisticated. Whereas operations such as Angelfire and GeoCities have existed since the early days of the Web, newer offerings from, for example, Facebook and MySpace currently have large followings. These operations often brand themselves as social network services rather than simply as web page hosts.
Advertising on popular web pages can be lucrative, and e-commerce or the sale of products and services directly via the Web continues to grow.
In the early days, web pages were usually created as sets of complete and isolated HTML text files stored on a web server. More recently, websites are more often created using content management system (CMS) or wiki software with, initially, very little content. Contributors to these systems, who may be paid staff, members of a club or other organisation or members of the public, fill underlying databases with content using editing pages designed for that purpose, while casual visitors view and read this content in its final HTML form. There may or may not be editorial, approval and security systems built into the process of taking newly entered content and making it available to the target visitors.
Social impact
The Internet has made possible entirely new forms of social interaction, activities and organizing, thanks to its basic features such as widespread usability and access.
Social networking websites such as Facebook and MySpace have created a new form of socialization and interaction. Users of these sites are able to add a wide variety of items to their personal pages, to indicate common interests, and to connect with others. It is also possible to find a large circle of existing acquaintances, especially if a site allows users to utilize their real names, and to allow communication among large existing groups of people.
Sites like exist to allow wider announcement of groups which may exist mainly for face-to-face meetings, but which may have a variety of minor interactions over their group's site at , or other similar sites.
Political organization and censorship
For more details on this topic, see Internet censorship.
In democratic societies, the Internet has achieved new relevance as a political tool. The presidential campaign of Howard Dean in 2004 in the United States became famous for its ability to generate donations via the Internet. Many political groups use the Internet to achieve a whole new method of organizing, in order to carry out Internet activism.
Some governments, such as those of Cuba, Iran, North Korea, Myanmar, the People's Republic of China, and Saudi Arabia, restrict what people in their countries can access on the Internet, especially political and religious content. This is accomplished through software that filters domains and content so that they may not be easily accessed or obtained without elaborate circumvention.
In Norway, Denmark, Finland and Sweden, major Internet service providers have voluntarily (possibly to avoid such an arrangement being turned into law) agreed to restrict access to sites listed by police. While this list of forbidden URLs is only supposed to contain addresses of known child pornography sites, the content of the list is secret.[citation needed]
Many countries, including the United States, have enacted laws making the possession or distribution of certain material, such as child pornography, illegal, but do not use filtering software.
There are many free and commercially available software programs with which a user can choose to block offensive websites on individual computers or networks, such as to limit a child's access to pornography or violence. See Content-control software.
Leisure activities
The Internet has been a major source of leisure since before the World Wide Web, with entertaining social experiments such as MUDs and MOOs being conducted on university servers, and humor-related Usenet groups receiving much of the main traffic. Today, many Internet forums have sections devoted to games and funny videos; short cartoons in the form of Flash movies are also popular. Over 6 million people use blogs or message boards as a means of communication and for the sharing of ideas.
The pornography and gambling industries have both taken full advantage of the World Wide Web, and often provide a significant source of advertising revenue for other websites. Although many governments have attempted to put restrictions on both industries' use of the Internet, this has generally failed to stop their widespread popularity.
One main area of leisure on the Internet is multiplayer gaming. This form of leisure creates communities, bringing people of all ages and origins to enjoy the fast-paced world of multiplayer games. These range from MMORPG to first-person shooters, from role-playing games to online gambling. This has revolutionized the way many people interact and spend their free time on the Internet.
While online gaming has been around since the 1970s, modern modes of online gaming began with services such as GameSpy and MPlayer, to which players of games would typically subscribe. Non-subscribers were limited to certain types of gameplay or certain games.
Many use the Internet to access and download music, movies and other works for their enjoyment and relaxation. As discussed above, there are paid and unpaid sources for all of these, using centralized servers and distributed peer-to-peer technologies. Discretion is needed as some of these sources take more care over the original artists' rights and over copyright laws than others.
Many use the World Wide Web to access news, weather and sports reports, to plan and book holidays and to find out more about their random ideas and casual interests.
People use chat, messaging and e-mail to make and stay in touch with friends worldwide, sometimes in the same way as some previously had pen pals. Social networking websites like MySpace, Facebook and many others like them also put and keep people in contact for their enjoyment.
The Internet has seen a growing number of Web desktops, where users can access their files, folders, and settings via the Internet.
Cyberslacking has become a serious drain on corporate resources; the average UK employee spends 57 minutes a day surfing the Web at work, according to a study by Peninsula Business Services.[9]
Complex architecture
Many computer scientists see the Internet as a "prime example of a large-scale, highly engineered, yet highly complex system".[10] The Internet is extremely heterogeneous. (For instance, data transfer rates and physical characteristics of connections vary widely.) The Internet exhibits "emergent phenomena" that depend on its large-scale organization. For example, data transfer rates exhibit temporal self-similarity. Further adding to the complexity of the Internet is the ability of more than one computer to use the Internet through only one node, thus creating the possibility for a very deep and hierarchal sub-network that can theoretically be extended infinitely (disregarding the programmatic limitations of the IPv4 protocol). However, since principles of this architecture date back to the 1960s, it might not be a solution best suited to modern needs, and thus the possibility of developing alternative structures is currently being looked into.[11]
According to a June 2007 article in Discover magazine, the combined weight of all the electrons moved within the Internet in a day is 0.2 millionths of an ounce.[12] Others have estimated this at nearer 2 ounces (50 grams).[13]
Marketing
The Internet has also become a large market for companies; some of the biggest companies today have grown by taking advantage of the efficient nature of low-cost advertising and commerce through the Internet, also known as e-commerce. It is the fastest way to spread information to a vast number of people simultaneously. The Internet has also subsequently revolutionized shopping—for example; a person can order a CD online and receive it in the mail within a couple of days, or download it directly in some cases. The Internet has also greatly facilitated personalized marketing which allows a company to market a product to a specific person or a specific group of people more so than any other advertising medium.
Examples of personalized marketing include online communities such as MySpace, Friendster, Orkut, Facebook and others which thousands of Internet users join to advertise themselves and make friends online. Many of these users are young teens and adolescents ranging from 13 to 25 years old. In turn, when they advertise themselves they advertise interests and hobbies, which online marketing companies can use as information as to what those users will purchase online, and advertise their own companies' products to those users.
icip 2017是不是ei检索
首先要看清楚是ICIP 还是 IEEE ICIP。
2017 IEEE ICIP 在北京举办。 IEEE ICIP 是 CCF (中国计算机学会推荐国际学术会议和期刊目录) 会议论文C类。应该还不算差的吧,应该是 ei 检索。具体还要看看官网是否给出解释。好的文章是可以在SCI中检索的。
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