In the process of encoding and decoding,erasure codes over binary fields,which just need AND operations and XOR operations and therefore have a high computational efficiency,are widely used in various fields of inform...In the process of encoding and decoding,erasure codes over binary fields,which just need AND operations and XOR operations and therefore have a high computational efficiency,are widely used in various fields of information technology.A matrix decoding method is proposed in this paper.The method is a universal data reconstruction scheme for erasure codes over binary fields.Besides a pre-judgment that whether errors can be recovered,the method can rebuild sectors of loss data on a fault-tolerant storage system constructed by erasure codes for disk errors.Data reconstruction process of the new method has simple and clear steps,so it is beneficial for implementation of computer codes.And more,it can be applied to other non-binary fields easily,so it is expected that the method has an extensive application in the future.展开更多
Let Fq be a finite field. In this paper, a construction of Cartesian au-thentication codes from the normal form of a class of nilpotent matrices over the field Fq is presented. Moreover, assume that the encoding rules...Let Fq be a finite field. In this paper, a construction of Cartesian au-thentication codes from the normal form of a class of nilpotent matrices over the field Fq is presented. Moreover, assume that the encoding rules are chosen according to a uniform probability distribution, the probabilities PI and PS, of a successful im-personation attack and of a successful substitution attack respectively, of these codes are also computed.展开更多
Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC...Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC） scheme based on multi-user detection for the multiple unicast transmission is proposed.Theoretic analysis and simulation results demonstrate that,compared with the conventional cooperation（CC） scheme and network-coded cooperation（NCC） scheme,CFNCC would obtain higher network throughput and consumes less time slots.Moreover,a further investigation is made for the symbol error probability（SEP） performance of CFNCC scheme,and SEPs of CFNCC scheme are compared with those of NCC scheme in various scenarios for different signal to noise ratio（SNR） values.展开更多
We construct one multi-sender authentication code by algebraic combination method from eigenvalues and eigenvectors of the matrix over nite elds. Some parameters and the probabilities of three kinds of successful atta...We construct one multi-sender authentication code by algebraic combination method from eigenvalues and eigenvectors of the matrix over nite elds. Some parameters and the probabilities of three kinds of successful attack of this code are also computed. For multi-sender authentication code,it allows a group of senders to construct an authenticated message for a receiver such that the receiver can verify authenticity of the received message.展开更多
三峡库区周期性水位升降引起的消落带岩体劣化对典型危岩岸坡稳定性具有重大影响。基于野外调研及地勘资料,采用通用离散单元法程序(universal distinct element code,简称UDEC)研究了消落带劣化区形态对近水平层状高陡危岩岸坡的稳定...三峡库区周期性水位升降引起的消落带岩体劣化对典型危岩岸坡稳定性具有重大影响。基于野外调研及地勘资料,采用通用离散单元法程序(universal distinct element code,简称UDEC)研究了消落带劣化区形态对近水平层状高陡危岩岸坡的稳定性影响。研究表明:目前三峡库区巫山段的近水平层状危岩岸坡消落带岩体劣化严重,在不同消落带劣化区存在紧密层状、松散碎裂状、溶蚀凹腔状、含挤压碎裂带等典型消落带劣化区形态;含有第1种消落带劣化区形态的危岩岸坡稳定性较好,危岩体位移较小,失稳模式为滑移破坏;含有第2种消落带劣化区形态的危岩岸坡危岩体先向坡内偏移,其后随着消落带岩体支撑强度弱化向坡外倾倒破坏;含有第3种消落带劣化区形态的危岩岸坡危岩体向坡外位移较大,失稳模式为倾倒破坏;含有第4种消落带劣化区形态的危岩岸坡稳定性主要受挤压破碎带的力学性质控制,易产生沿破碎带切割面的旋转滑移破坏;通过对以上4种劣化区形态的危岩岸坡增加防治加固措施,危岩体的变形位移得到了不同程度的有效控制。展开更多
为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(ver...为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(versatile video coding,VVC)对稀疏光场进行压缩;然后,在解码端使用2个关键分支模块,即视差估计模块和空间角度联合卷积模块,以获取光场图像全局的几何信息,确保在密集纹理和遮挡区域能够更充分地恢复特征;最后,为了挖掘2个分支融合特征的结构信息,构建了双向视图的堆栈结构,并运用几何感知的细化网络以重建高质量的密集光场.实验结果表明,与已有国际上流行的光场图像编码方法相比,所提出的方法具有显著优势.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61501064Sichuan Provincial Science and Technology Project under Grant No.2016GZ0122
文摘In the process of encoding and decoding,erasure codes over binary fields,which just need AND operations and XOR operations and therefore have a high computational efficiency,are widely used in various fields of information technology.A matrix decoding method is proposed in this paper.The method is a universal data reconstruction scheme for erasure codes over binary fields.Besides a pre-judgment that whether errors can be recovered,the method can rebuild sectors of loss data on a fault-tolerant storage system constructed by erasure codes for disk errors.Data reconstruction process of the new method has simple and clear steps,so it is beneficial for implementation of computer codes.And more,it can be applied to other non-binary fields easily,so it is expected that the method has an extensive application in the future.
文摘Let Fq be a finite field. In this paper, a construction of Cartesian au-thentication codes from the normal form of a class of nilpotent matrices over the field Fq is presented. Moreover, assume that the encoding rules are chosen according to a uniform probability distribution, the probabilities PI and PS, of a successful im-personation attack and of a successful substitution attack respectively, of these codes are also computed.
基金supported by the National Natural Science Foundation of China(6104000561001126+5 种基金61271262)the China Postdoctoral Science Foundation Funded Project(201104916382012T50789)the Natural Science Foundation of Shannxi Province of China(2011JQ8036)the Special Fund for Basic Scientific Research of Central Colleges (CHD2012ZD005)the Research Fund of Zhejiang University of Technology(20100244)
文摘Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC） scheme based on multi-user detection for the multiple unicast transmission is proposed.Theoretic analysis and simulation results demonstrate that,compared with the conventional cooperation（CC） scheme and network-coded cooperation（NCC） scheme,CFNCC would obtain higher network throughput and consumes less time slots.Moreover,a further investigation is made for the symbol error probability（SEP） performance of CFNCC scheme,and SEPs of CFNCC scheme are compared with those of NCC scheme in various scenarios for different signal to noise ratio（SNR） values.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61179026)the Fundamental Research of the Central Universities of China Civil Aviation University of Science Special(Grant No.3122016L005)
文摘We construct one multi-sender authentication code by algebraic combination method from eigenvalues and eigenvectors of the matrix over nite elds. Some parameters and the probabilities of three kinds of successful attack of this code are also computed. For multi-sender authentication code,it allows a group of senders to construct an authenticated message for a receiver such that the receiver can verify authenticity of the received message.
文摘三峡库区周期性水位升降引起的消落带岩体劣化对典型危岩岸坡稳定性具有重大影响。基于野外调研及地勘资料,采用通用离散单元法程序(universal distinct element code,简称UDEC)研究了消落带劣化区形态对近水平层状高陡危岩岸坡的稳定性影响。研究表明:目前三峡库区巫山段的近水平层状危岩岸坡消落带岩体劣化严重,在不同消落带劣化区存在紧密层状、松散碎裂状、溶蚀凹腔状、含挤压碎裂带等典型消落带劣化区形态;含有第1种消落带劣化区形态的危岩岸坡稳定性较好,危岩体位移较小,失稳模式为滑移破坏;含有第2种消落带劣化区形态的危岩岸坡危岩体先向坡内偏移,其后随着消落带岩体支撑强度弱化向坡外倾倒破坏;含有第3种消落带劣化区形态的危岩岸坡危岩体向坡外位移较大,失稳模式为倾倒破坏;含有第4种消落带劣化区形态的危岩岸坡稳定性主要受挤压破碎带的力学性质控制,易产生沿破碎带切割面的旋转滑移破坏;通过对以上4种劣化区形态的危岩岸坡增加防治加固措施,危岩体的变形位移得到了不同程度的有效控制。
文摘为了克服基于单一视差合成的光场图像编码方法在遮挡区域无法恢复纹理细节的问题,提出一种基于多特征融合和几何感知网络的光场图像编码方法,以进一步提升遮挡场景下光场图像的压缩性能.首先,对密集光场稀疏采样,使用通用视频编码器(versatile video coding,VVC)对稀疏光场进行压缩;然后,在解码端使用2个关键分支模块,即视差估计模块和空间角度联合卷积模块,以获取光场图像全局的几何信息,确保在密集纹理和遮挡区域能够更充分地恢复特征;最后,为了挖掘2个分支融合特征的结构信息,构建了双向视图的堆栈结构,并运用几何感知的细化网络以重建高质量的密集光场.实验结果表明,与已有国际上流行的光场图像编码方法相比,所提出的方法具有显著优势.
