As a more trackable performance metric for secrecy capacity,the secure degrees of freedom(SDoF)are widely studied for most multiuser networks in the high signal to noise ratio(SNR)region.However,the SDoF for these net...As a more trackable performance metric for secrecy capacity,the secure degrees of freedom(SDoF)are widely studied for most multiuser networks in the high signal to noise ratio(SNR)region.However,the SDoF for these networks under rank-deficiency and arbitrary antenna configurations have not yet been determined.In this paper,the SDoF of two-user general multiple-input multiple-output(MIMO)interference channel with confidential messages(ICCM)under rank-deficiency are derived.For the two-user rank-deficient MIMO ICCM,the model is generalized to fully asymmetric settings,where the transmitters and receivers are equipped with arbitrary antennas.The outer bound of SDoF is the union of three outer bounds that are based on the Fano’s inequality and the secrecy constraints,the secrecy penalty lemma and the role of a helper lemma,and the transmitters cooperation,respectively.The SDoF region is subdivided into five regions according to the number of transceivers antennas,and each region has an achievability scheme with designed null space transmission and alignment techniques.Numerical results indicate that the SDoF increase at first and then decrease as the rank of the channel matrix decreases.The SDoF improve by increasing the transmitting antenna or reducing receiving antenna,but the effect of the transmitting antenna is greater.展开更多
建立具有设计意义的地震动总输入能量谱是实现结构能量设计的基础。根据中长周期段修正的加速度反应谱及地震动有效持时,提出了一种生成地震动输入能量谱的方法。统计270组人工波的时程分析结果,得到了以等效速度表征的四段式弹性单自由...建立具有设计意义的地震动总输入能量谱是实现结构能量设计的基础。根据中长周期段修正的加速度反应谱及地震动有效持时,提出了一种生成地震动输入能量谱的方法。统计270组人工波的时程分析结果,得到了以等效速度表征的四段式弹性单自由度(single degree of freedom,SDOF)体系总输入能量谱,并给出了不同场地类型、抗震设防烈度等设计条件下归一化等效速度谱的参数取值。在考虑延性系数及刚度折减系数的影响后,提出了弹塑性SDOF体系修正输入能量谱的等效速度谱,估算了引起结构损伤的滞回耗能占总能量的比值。该能量谱可为基于能量的结构设计及研究提供参考。展开更多
为了确定弹塑性单自由度(single degree of freedom,SDOF)体系地震输入能,分析了中美场地土剪切波速转换关系,将从美国PEER地震记录数据库选取的220条强震记录按中国场地土类型进行分类,基于能量平衡原理,采用归一化方法,建议了一种基...为了确定弹塑性单自由度(single degree of freedom,SDOF)体系地震输入能,分析了中美场地土剪切波速转换关系,将从美国PEER地震记录数据库选取的220条强震记录按中国场地土类型进行分类,基于能量平衡原理,采用归一化方法,建议了一种基于复合强度指标的弹性SDOF体系三段式等效速度谱.分析了5类场地土条件下SDOF体系系统参数对地震输入等效速度谱的影响.研究结果表明:刚度折减系数对等效速度谱无明显影响;延性系数和阻尼比增大均对等效速度谱峰值和下降段衰减速度有削弱作用.综合考虑各类影响因素,通过参数多次拟合,得出弹性SDOF体系归一化等效速度谱峰值段及下降段修正系数,提出了一种适用于我国场地土类型、可直接供设计使用的弹塑性SDOF体系归一化等效速度谱确定方法,并验证了其有效性.展开更多
基金supported by the National Key Research and Development(R&D)Program of China(2018YFE0205503)the National Natural Science Foundation of China(62071066)。
文摘As a more trackable performance metric for secrecy capacity,the secure degrees of freedom(SDoF)are widely studied for most multiuser networks in the high signal to noise ratio(SNR)region.However,the SDoF for these networks under rank-deficiency and arbitrary antenna configurations have not yet been determined.In this paper,the SDoF of two-user general multiple-input multiple-output(MIMO)interference channel with confidential messages(ICCM)under rank-deficiency are derived.For the two-user rank-deficient MIMO ICCM,the model is generalized to fully asymmetric settings,where the transmitters and receivers are equipped with arbitrary antennas.The outer bound of SDoF is the union of three outer bounds that are based on the Fano’s inequality and the secrecy constraints,the secrecy penalty lemma and the role of a helper lemma,and the transmitters cooperation,respectively.The SDoF region is subdivided into five regions according to the number of transceivers antennas,and each region has an achievability scheme with designed null space transmission and alignment techniques.Numerical results indicate that the SDoF increase at first and then decrease as the rank of the channel matrix decreases.The SDoF improve by increasing the transmitting antenna or reducing receiving antenna,but the effect of the transmitting antenna is greater.
文摘建立具有设计意义的地震动总输入能量谱是实现结构能量设计的基础。根据中长周期段修正的加速度反应谱及地震动有效持时,提出了一种生成地震动输入能量谱的方法。统计270组人工波的时程分析结果,得到了以等效速度表征的四段式弹性单自由度(single degree of freedom,SDOF)体系总输入能量谱,并给出了不同场地类型、抗震设防烈度等设计条件下归一化等效速度谱的参数取值。在考虑延性系数及刚度折减系数的影响后,提出了弹塑性SDOF体系修正输入能量谱的等效速度谱,估算了引起结构损伤的滞回耗能占总能量的比值。该能量谱可为基于能量的结构设计及研究提供参考。
文摘为了确定弹塑性单自由度(single degree of freedom,SDOF)体系地震输入能,分析了中美场地土剪切波速转换关系,将从美国PEER地震记录数据库选取的220条强震记录按中国场地土类型进行分类,基于能量平衡原理,采用归一化方法,建议了一种基于复合强度指标的弹性SDOF体系三段式等效速度谱.分析了5类场地土条件下SDOF体系系统参数对地震输入等效速度谱的影响.研究结果表明:刚度折减系数对等效速度谱无明显影响;延性系数和阻尼比增大均对等效速度谱峰值和下降段衰减速度有削弱作用.综合考虑各类影响因素,通过参数多次拟合,得出弹性SDOF体系归一化等效速度谱峰值段及下降段修正系数,提出了一种适用于我国场地土类型、可直接供设计使用的弹塑性SDOF体系归一化等效速度谱确定方法,并验证了其有效性.
