视频流量逐渐在网络中占据主导地位,且视频平台大多对其进行加密传输。虽然加密传输视频可以有效保护用户隐私,但是也增加了监管有害视频传播的难度.现有的加密视频识别方法基于TCP(Transmission Control Protocol)传输协议头部信息和HT...视频流量逐渐在网络中占据主导地位,且视频平台大多对其进行加密传输。虽然加密传输视频可以有效保护用户隐私,但是也增加了监管有害视频传播的难度.现有的加密视频识别方法基于TCP(Transmission Control Protocol)传输协议头部信息和HTTP/1.1(Hypertext Transfer Protocol Version1.1)的传输模式,提取应用层音视频数据单元传输长度序列来实现视频识别.但是随着基于UDP(User Datagram Protocol)的QUIC(Quick UDP Internet Connections)协议及基于QUIC实现的HTTP/3(Hypertext Transfer Protocol Version 3)协议应用于视频传输,已有方法不再适用.HTTP/3协议缺少类似TCP的头部信息,且使用了多路复用机制,并对几乎所有数据进行了加密,此外,视频平台开始使用多片段合并分发技术,这给从网络流量中精准识别加密视频带来了巨大挑战。本文基于HTTP/3协议中的控制信息特征,提出了从HTTP/3加密视频流中提取数据传输特征并进行修正的方法,最大程度复原出应用层音视频长度特征.面向多片段合并分发导致的海量匹配问题,本文基于明文指纹库设计了键值数据库来实现视频的快速识别.实验结果表明,本文提出的基于HTTP/3传输特性的加密视频识别方法能够在包含36万个真实视频指纹的YouTube大规模指纹库中达到接近99%的准确率,100%的精确率以及99.32%的F1得分,对传输过程中加人了填充顿的Facebook平台,在包含28万个真实视频指纹的大规模指纹库中达到95%的准确率、100%的精确率以及96.45%的F1得分,在具有同样特性的Instagram平台中,最高可达到97.57%的F1得分,且本方法在所有指纹库中的平均视频识别时间均低于0.4秒.本文的方法首次解决了使用HTTP/3传输的加密视频在大规模指纹库场景中的识别问题,具有很强的实用性和通用性.展开更多
ICTS(Intelligent Chinese Tutoring System)是关于汉语知识的智能型计算机辅助教学系统。本文首先给出了ICTS的总体结构和各主要部分的设计思想,提出了基于多知识源的推理机制;接着阐述了hypertext技术在ICTS构造中的应用;最后对ICTS...ICTS(Intelligent Chinese Tutoring System)是关于汉语知识的智能型计算机辅助教学系统。本文首先给出了ICTS的总体结构和各主要部分的设计思想,提出了基于多知识源的推理机制;接着阐述了hypertext技术在ICTS构造中的应用;最后对ICTS的实现作出了总结。展开更多
Some problems encountered in developing navigational graph controlling program in ORACLE multimedia graphic development tool-Graphics such as multi-window creation,button simulation,computing descendant number and wri...Some problems encountered in developing navigational graph controlling program in ORACLE multimedia graphic development tool-Graphics such as multi-window creation,button simulation,computing descendant number and writing text etc.arc discussed,Since all kinds of algorithm related with the problems have been checked and proved to be correct,they have the feature of universal significance.展开更多
For its suitability for management of nonlinear information and flexible struc-ture.hypertext has a wide scope of application,but in the past,most of hypertext modelsor systems were used for management of non-engineer...For its suitability for management of nonlinear information and flexible struc-ture.hypertext has a wide scope of application,but in the past,most of hypertext modelsor systems were used for management of non-engineering data.As engineering data is al-ways large in volume and entails much complicated management,there are many problemsto be solved before hypertext can be used for management of engineering data.This paperpresents HyVc,a Structure data model with a version node,which is more subitable formanagement of engineering data than ever before,and a structure node,which reduces thenumber of nodes within a hypertext network to make the structure clearer and easier fornavigation,and the enhanced knowledge presentation capability and dynamic retrievingcapability of the hypertext network as results of these new developments as well.展开更多
Version control is an urgent problem to be solved at present for data management. Based on the authors' hypertext data model with version control,some details about the storage strategy are discussed. A new strate...Version control is an urgent problem to be solved at present for data management. Based on the authors' hypertext data model with version control,some details about the storage strategy are discussed. A new strategy to define some key nodes within the version derivation graph is presented and some implementation details are described. At last, the performance of different strategies are compared with each other.展开更多
文摘视频流量逐渐在网络中占据主导地位,且视频平台大多对其进行加密传输。虽然加密传输视频可以有效保护用户隐私,但是也增加了监管有害视频传播的难度.现有的加密视频识别方法基于TCP(Transmission Control Protocol)传输协议头部信息和HTTP/1.1(Hypertext Transfer Protocol Version1.1)的传输模式,提取应用层音视频数据单元传输长度序列来实现视频识别.但是随着基于UDP(User Datagram Protocol)的QUIC(Quick UDP Internet Connections)协议及基于QUIC实现的HTTP/3(Hypertext Transfer Protocol Version 3)协议应用于视频传输,已有方法不再适用.HTTP/3协议缺少类似TCP的头部信息,且使用了多路复用机制,并对几乎所有数据进行了加密,此外,视频平台开始使用多片段合并分发技术,这给从网络流量中精准识别加密视频带来了巨大挑战。本文基于HTTP/3协议中的控制信息特征,提出了从HTTP/3加密视频流中提取数据传输特征并进行修正的方法,最大程度复原出应用层音视频长度特征.面向多片段合并分发导致的海量匹配问题,本文基于明文指纹库设计了键值数据库来实现视频的快速识别.实验结果表明,本文提出的基于HTTP/3传输特性的加密视频识别方法能够在包含36万个真实视频指纹的YouTube大规模指纹库中达到接近99%的准确率,100%的精确率以及99.32%的F1得分,对传输过程中加人了填充顿的Facebook平台,在包含28万个真实视频指纹的大规模指纹库中达到95%的准确率、100%的精确率以及96.45%的F1得分,在具有同样特性的Instagram平台中,最高可达到97.57%的F1得分,且本方法在所有指纹库中的平均视频识别时间均低于0.4秒.本文的方法首次解决了使用HTTP/3传输的加密视频在大规模指纹库场景中的识别问题,具有很强的实用性和通用性.
文摘ICTS(Intelligent Chinese Tutoring System)是关于汉语知识的智能型计算机辅助教学系统。本文首先给出了ICTS的总体结构和各主要部分的设计思想,提出了基于多知识源的推理机制;接着阐述了hypertext技术在ICTS构造中的应用;最后对ICTS的实现作出了总结。
文摘Some problems encountered in developing navigational graph controlling program in ORACLE multimedia graphic development tool-Graphics such as multi-window creation,button simulation,computing descendant number and writing text etc.arc discussed,Since all kinds of algorithm related with the problems have been checked and proved to be correct,they have the feature of universal significance.
文摘For its suitability for management of nonlinear information and flexible struc-ture.hypertext has a wide scope of application,but in the past,most of hypertext modelsor systems were used for management of non-engineering data.As engineering data is al-ways large in volume and entails much complicated management,there are many problemsto be solved before hypertext can be used for management of engineering data.This paperpresents HyVc,a Structure data model with a version node,which is more subitable formanagement of engineering data than ever before,and a structure node,which reduces thenumber of nodes within a hypertext network to make the structure clearer and easier fornavigation,and the enhanced knowledge presentation capability and dynamic retrievingcapability of the hypertext network as results of these new developments as well.
文摘Version control is an urgent problem to be solved at present for data management. Based on the authors' hypertext data model with version control,some details about the storage strategy are discussed. A new strategy to define some key nodes within the version derivation graph is presented and some implementation details are described. At last, the performance of different strategies are compared with each other.
