在采用多天线高阶QAM的MIMO通信系统中,现有基于信道分组并行检测算法虽然接近最优检测性能但以牺牲计算效率为代价.针对这一问题,本文提出一种MMSE准则下基于信道分组的并行检测算法,不但有效降低计算复杂度,而且仍保证检测性能.该算...在采用多天线高阶QAM的MIMO通信系统中,现有基于信道分组并行检测算法虽然接近最优检测性能但以牺牲计算效率为代价.针对这一问题,本文提出一种MMSE准则下基于信道分组的并行检测算法,不但有效降低计算复杂度,而且仍保证检测性能.该算法采用MMSE准则下格归约算法改进分组后条件较好子信道矩阵特性,并在消除参考信号基础上利用改进的子信道矩阵对剩余信号以非线性方式进行检测.仿真结果表明:对4@4和6@6MIMO系统,该算法检测性能达到最优,对于8@8 MIMO系统,比最优算法所需信噪比提高约1dB.复杂度分析表明:相比现有信道分组检测算法,相同检测性能下该算法在6@6 M IMO系统中复杂度降低90%以上,在8@8 MIMO系统中复杂度降低98%以上.展开更多
作为胶片电影中最常见的谷粒噪声,其对应的修复算法虽然很多但却存在过度平滑、复杂度高等诸多缺陷.因此运用RGB通道的相关性,提出一种基于分区域双边滤波的噪声修复算法,目标是去除胶片电影中常见的谷粒噪声,为后续斑点、划痕、稳像、...作为胶片电影中最常见的谷粒噪声,其对应的修复算法虽然很多但却存在过度平滑、复杂度高等诸多缺陷.因此运用RGB通道的相关性,提出一种基于分区域双边滤波的噪声修复算法,目标是去除胶片电影中常见的谷粒噪声,为后续斑点、划痕、稳像、闪烁等修复工作提供质量保证.测试结果表明:运用本算法去噪后的图像不仅能满足人眼的视觉要求,而且其峰值信噪比(peak signal to noise ratio,PSNR)值和结构相似性(structural similarity,SSIM)值明显提高,运行时间也几乎缩短为原来的一半,这不仅会提高旧电影的商业价值,而且对挽救国内外大量史实资料具有重要意义.展开更多
Close-distance coal seams are widely distributed over China,and the coal pillars left by the overlying coal seams afect the retracement channel of the underlying coal seam in the stopping stage.Based on the engineerin...Close-distance coal seams are widely distributed over China,and the coal pillars left by the overlying coal seams afect the retracement channel of the underlying coal seam in the stopping stage.Based on the engineering background of close-distance seam mining in a coal mine,the reasonable position of the underlying coal seam's stopping line and the support method of the large section roadway during stopping are investigated using feld measurements,similar simulation experiments,and numerical simulations.There are three types of location relationships between the stopping line of the underlying coal seam and the stopping line of the overlying coal seam:"externally staggered with the upper stopping line"(ESUL,stops mining under the overlying goaf),"overlapped with upper stopping line"(OUL),and"internally staggered with the upper stopping line"(ISUL,ISUL-SD for shorter internal staggered distances,ISUL-LD for longer ones).There are diferent stress arch structures in the overlying strata of the above three positions,and the stress arch evolution process exists in the process of ESUL→OUL→ISUL-SD→ISUL-LD:a front and rear double stress arch structure→the front arch gradually decreases→the front arch dies out,and the double arch synthesizes the single arch→the single-arch range expands→the nested double arch.The relationship between the stress arch structure and the position of the stopping line is evaluated as follows:(1)ESUL:the stress concentration in the roof plate of the retracement channel of the underlying coal seam is the highest,because the overburden block of the extensive collapse zone acts directly on the roof plate of the retracement channel,resulting in relative difculties in roof support.(2)OUL:although the retracement channel roof pressure is minimal,the overlying rock structure has the potential for rotation or slippage instability.(3)ISUL-SD:the pressure on the roof of the retracement channel is small and the overburden structure is stable,which is conducive to the safe retraction of the s展开更多
We present an unequal decoding power allocation （UDPA） approach for minimization of the receiver power consumption subject to a given quality of service （QoS）, by exploiting data partitioning and turbo decoding. W...We present an unequal decoding power allocation （UDPA） approach for minimization of the receiver power consumption subject to a given quality of service （QoS）, by exploiting data partitioning and turbo decoding. We assign unequal decoding power of forward error correction （FEC） to data partitions with different priority by jointly considering the source coding, channel coding and receiver power consumption. The proposed scheme is applied to H.264 video over additive white Gaussion noise （AWGN） channel, and achieves excellent tradeoff between video delivery quality and power consumption, and yields significant power saving compared with the conventional equal decoding power allocation （EDPA） approach in wireless video transmission.展开更多
Many problems of discrete optimization are connected with partition of the n-dimensional space into certain subsets, and the requirements needed for these subsets can be geometrical—for instance, their sphericity—or...Many problems of discrete optimization are connected with partition of the n-dimensional space into certain subsets, and the requirements needed for these subsets can be geometrical—for instance, their sphericity—or they can be connected with?certain metrics—for instance, the requirement that subsets are Dirichlet’s regions with Hamming’s metrics [1]. Often partitions into some subsets are considered, on which a functional is optimized [2]. In the present work, the partitions of the n-dimensional space into subsets with “zero” limitation are considered. Such partitions allow us to construct the set of the group codes, V, and the set of the channels, A, between the arbitrary elements, V and A, having correcting relation between them. Descriptions of some classes of both perfect and imperfect codes in the additive channel are presented, too. A way of constructing of group codes correcting the errors in the additive channels is presented, and this method is a further generalization of Hamming’s method of code construction.展开更多
淮南500 k V主网架逐渐成型,500 k V和220 k V电网间高低压电磁环网已经形成。针对淮南电网特点,对淮南220 k V电磁环网进行了解环分析,提出了一套合理的解环方案,实现对淮南220 k V电网的分区运行,并考虑一个分区失去上级电源后另一分...淮南500 k V主网架逐渐成型,500 k V和220 k V电网间高低压电磁环网已经形成。针对淮南电网特点,对淮南220 k V电磁环网进行了解环分析,提出了一套合理的解环方案,实现对淮南220 k V电网的分区运行,并考虑一个分区失去上级电源后另一分区作为备用电源这一典型场景下的供电可靠性。采用案例验证了解环方案的合理性。展开更多
在发射天线数为NT、接收天线数为NR的MIMO系统中,并行检测算法可达到最优的检测性能,但现有系统中用到的信道分组方法是计算 NT 次矩阵广义逆来完成信道分组,随着天线数量的不断增加,矩阵求逆计算量会快速增加,从而进一步加剧并行检测...在发射天线数为NT、接收天线数为NR的MIMO系统中,并行检测算法可达到最优的检测性能,但现有系统中用到的信道分组方法是计算 NT 次矩阵广义逆来完成信道分组,随着天线数量的不断增加,矩阵求逆计算量会快速增加,从而进一步加剧并行检测算法计算复杂度。针对该问题,文章证明了:在并行检测算法中,只须一次矩阵广义逆的计算即可完成信道分组。仿真结果表明,应用新的信道分组方法的格归约并行检测算法的性能不变。展开更多
文摘在采用多天线高阶QAM的MIMO通信系统中,现有基于信道分组并行检测算法虽然接近最优检测性能但以牺牲计算效率为代价.针对这一问题,本文提出一种MMSE准则下基于信道分组的并行检测算法,不但有效降低计算复杂度,而且仍保证检测性能.该算法采用MMSE准则下格归约算法改进分组后条件较好子信道矩阵特性,并在消除参考信号基础上利用改进的子信道矩阵对剩余信号以非线性方式进行检测.仿真结果表明:对4@4和6@6MIMO系统,该算法检测性能达到最优,对于8@8 MIMO系统,比最优算法所需信噪比提高约1dB.复杂度分析表明:相比现有信道分组检测算法,相同检测性能下该算法在6@6 M IMO系统中复杂度降低90%以上,在8@8 MIMO系统中复杂度降低98%以上.
文摘作为胶片电影中最常见的谷粒噪声,其对应的修复算法虽然很多但却存在过度平滑、复杂度高等诸多缺陷.因此运用RGB通道的相关性,提出一种基于分区域双边滤波的噪声修复算法,目标是去除胶片电影中常见的谷粒噪声,为后续斑点、划痕、稳像、闪烁等修复工作提供质量保证.测试结果表明:运用本算法去噪后的图像不仅能满足人眼的视觉要求,而且其峰值信噪比(peak signal to noise ratio,PSNR)值和结构相似性(structural similarity,SSIM)值明显提高,运行时间也几乎缩短为原来的一半,这不仅会提高旧电影的商业价值,而且对挽救国内外大量史实资料具有重要意义.
基金supported by the National Natural Science Foundation of China(52004286)the Fundamental Research Funds for the Central Universities(2022XJNY02)+3 种基金the National Natural Science Foundation of China(51974317,52074296)the China Postdoctoral Science Foundation(2020T130701,2019M650895)the Fundamental Research Funds for the Central Universities(2022YJSNY18,2022YJSNY09)all of which were gratefully acknowledged.
文摘Close-distance coal seams are widely distributed over China,and the coal pillars left by the overlying coal seams afect the retracement channel of the underlying coal seam in the stopping stage.Based on the engineering background of close-distance seam mining in a coal mine,the reasonable position of the underlying coal seam's stopping line and the support method of the large section roadway during stopping are investigated using feld measurements,similar simulation experiments,and numerical simulations.There are three types of location relationships between the stopping line of the underlying coal seam and the stopping line of the overlying coal seam:"externally staggered with the upper stopping line"(ESUL,stops mining under the overlying goaf),"overlapped with upper stopping line"(OUL),and"internally staggered with the upper stopping line"(ISUL,ISUL-SD for shorter internal staggered distances,ISUL-LD for longer ones).There are diferent stress arch structures in the overlying strata of the above three positions,and the stress arch evolution process exists in the process of ESUL→OUL→ISUL-SD→ISUL-LD:a front and rear double stress arch structure→the front arch gradually decreases→the front arch dies out,and the double arch synthesizes the single arch→the single-arch range expands→the nested double arch.The relationship between the stress arch structure and the position of the stopping line is evaluated as follows:(1)ESUL:the stress concentration in the roof plate of the retracement channel of the underlying coal seam is the highest,because the overburden block of the extensive collapse zone acts directly on the roof plate of the retracement channel,resulting in relative difculties in roof support.(2)OUL:although the retracement channel roof pressure is minimal,the overlying rock structure has the potential for rotation or slippage instability.(3)ISUL-SD:the pressure on the roof of the retracement channel is small and the overburden structure is stable,which is conducive to the safe retraction of the s
基金supported by the Scientific Research Innovation Project of the Shanghai Municipal Education Commission (Grant No.08YZ18)the Key Project of Natural Science Foundation of China (Grant No.60832003)+2 种基金the National Natural Science Foundation of China (Grant Nos.60972137,60672052)the Innovation Foundation Project of Shanghai Universitythe Special Research Foundation of Shanghai Excellent Youth University Teacher Training
文摘We present an unequal decoding power allocation （UDPA） approach for minimization of the receiver power consumption subject to a given quality of service （QoS）, by exploiting data partitioning and turbo decoding. We assign unequal decoding power of forward error correction （FEC） to data partitions with different priority by jointly considering the source coding, channel coding and receiver power consumption. The proposed scheme is applied to H.264 video over additive white Gaussion noise （AWGN） channel, and achieves excellent tradeoff between video delivery quality and power consumption, and yields significant power saving compared with the conventional equal decoding power allocation （EDPA） approach in wireless video transmission.
文摘Many problems of discrete optimization are connected with partition of the n-dimensional space into certain subsets, and the requirements needed for these subsets can be geometrical—for instance, their sphericity—or they can be connected with?certain metrics—for instance, the requirement that subsets are Dirichlet’s regions with Hamming’s metrics [1]. Often partitions into some subsets are considered, on which a functional is optimized [2]. In the present work, the partitions of the n-dimensional space into subsets with “zero” limitation are considered. Such partitions allow us to construct the set of the group codes, V, and the set of the channels, A, between the arbitrary elements, V and A, having correcting relation between them. Descriptions of some classes of both perfect and imperfect codes in the additive channel are presented, too. A way of constructing of group codes correcting the errors in the additive channels is presented, and this method is a further generalization of Hamming’s method of code construction.
文摘淮南500 k V主网架逐渐成型,500 k V和220 k V电网间高低压电磁环网已经形成。针对淮南电网特点,对淮南220 k V电磁环网进行了解环分析,提出了一套合理的解环方案,实现对淮南220 k V电网的分区运行,并考虑一个分区失去上级电源后另一分区作为备用电源这一典型场景下的供电可靠性。采用案例验证了解环方案的合理性。
文摘在发射天线数为NT、接收天线数为NR的MIMO系统中,并行检测算法可达到最优的检测性能,但现有系统中用到的信道分组方法是计算 NT 次矩阵广义逆来完成信道分组,随着天线数量的不断增加,矩阵求逆计算量会快速增加,从而进一步加剧并行检测算法计算复杂度。针对该问题,文章证明了:在并行检测算法中,只须一次矩阵广义逆的计算即可完成信道分组。仿真结果表明,应用新的信道分组方法的格归约并行检测算法的性能不变。
