针对极化码串行抵消列表比特翻转(Successive Cancellation List Bit-Flip, SCLF)译码算法复杂度较高的问题,提出一种基于分布式奇偶校验码的低复杂度极化码SCLF译码(SCLF Decoding Algorithm for Low-Complexity Polar Codes Based on ...针对极化码串行抵消列表比特翻转(Successive Cancellation List Bit-Flip, SCLF)译码算法复杂度较高的问题,提出一种基于分布式奇偶校验码的低复杂度极化码SCLF译码(SCLF Decoding Algorithm for Low-Complexity Polar Codes Based on Distributed Parity Check Codes, DPC-SCLF)算法。与仅采用循环冗余校验(Cyclic Redundancy Check, CRC)码校验的SCLF译码算法不同,该算法首先利用极化信道偏序关系构造关键集,然后采用分布式奇偶校验(Parity Check, PC)码与CRC码结合的方式对错误比特进行检验、识别和翻转,提高了翻转精度,减少了重译码次数。此外,在译码时利用路径剪枝操作,提高了正确路径的竞争力,改善了误码性能,且利用提前终止译码进程操作,减少了译码比特数。仿真结果表明,与D-Post-SCLF译码算法和RCS-SCLF译码算法相比,所提出算法具有更低的译码复杂度且在中高信噪比下具有更好的误码性能。展开更多
This article explores the dynamics of the Diaspora's dual loyalties towards their home countries and host countries by using American Jewry as a case study. It argues that in liberal-democratic states,the shift in...This article explores the dynamics of the Diaspora's dual loyalties towards their home countries and host countries by using American Jewry as a case study. It argues that in liberal-democratic states,the shift in the Diaspora's loyalty towards the homeland vis-à-vis the host land is a result of the change to the host land's perception of where the acceptable boundary of the Diaspora's practice of dual loyalties is, or in other words, to what extent the Diaspora's support of the homeland is perceived to be acceptable by their host land. The reconstruction of this boundary is determined by four factors: the degree of political coordination between home states and host states, the attempt of the home state to mobilize its diasporas, the means advocated and supported by the Diaspora, and the severity of potential consequences due to the Diaspora's action.展开更多
Until now the Islamic Republic of Iran's adoption of an independent active deterrence strategy,a strategy based on threat assessment and self-assessment,has overall been a success.The sole exception involved Iraq ...Until now the Islamic Republic of Iran's adoption of an independent active deterrence strategy,a strategy based on threat assessment and self-assessment,has overall been a success.The sole exception involved Iraq in 1980 and was due to Iran's initial vulnerability following the revolution.As Saudi Arabia maneuvers with influence from US President Donald Trump,and given that Iran is unlikely to withdraw its military nuclear program under the existing security environment,the US and Israel ought to strengthen their nuclear deterrence capabilities against Iran.They need to issue clear,open,official retaliation commitments under a hypothetical nuclear scenario and bolster them with corresponding military and diplomatic capability.展开更多
In order to reduce the high complexity of the successive cancellation list(SCL) algorithm for polar codes,a simplified SCL decoding algorithm based on critical sets(CS-SCL decoding algorithm) is proposed.The algorithm...In order to reduce the high complexity of the successive cancellation list(SCL) algorithm for polar codes,a simplified SCL decoding algorithm based on critical sets(CS-SCL decoding algorithm) is proposed.The algorithm firstly constructs the critical sets according to the channel characteristics of the polar codes as well as comprehensively considering both the minimum Hamming weight(MHW) of the information bits and the channel reliability.The information bits within the critical sets and the path splitting are still performed by the SCL decoding algorithm while the information bits outside the critical sets are directly performed by the hard decision.Thus,the number of path ordering,copying,and deleting can be reduced during decoding.Furthermore,the computational complexity of the SCL decoding can also be reduced.Simulation results demonstrate that the decoding complexity of the proposed CS-SCL decoding algorithm,compared with the conventional SCL decoding algorithm,is reduced by at least 70%,while compared with the simplified SCL(PS-SS-SCL) algorithm which constructs the critical set with the first and second information bits of the Rate-1 nodes,its decoding complexity can also be reduced.Moreover,the loss of the error correction performance for the proposed CS-SCL decoding algorithm is minor.Therefore,the proposed CS-SCL algorithm is effective and can provide a reasonable tradeoff between the decoding performance and complexity for the decoding algorithm of polar codes.展开更多
文摘This article explores the dynamics of the Diaspora's dual loyalties towards their home countries and host countries by using American Jewry as a case study. It argues that in liberal-democratic states,the shift in the Diaspora's loyalty towards the homeland vis-à-vis the host land is a result of the change to the host land's perception of where the acceptable boundary of the Diaspora's practice of dual loyalties is, or in other words, to what extent the Diaspora's support of the homeland is perceived to be acceptable by their host land. The reconstruction of this boundary is determined by four factors: the degree of political coordination between home states and host states, the attempt of the home state to mobilize its diasporas, the means advocated and supported by the Diaspora, and the severity of potential consequences due to the Diaspora's action.
文摘Until now the Islamic Republic of Iran's adoption of an independent active deterrence strategy,a strategy based on threat assessment and self-assessment,has overall been a success.The sole exception involved Iraq in 1980 and was due to Iran's initial vulnerability following the revolution.As Saudi Arabia maneuvers with influence from US President Donald Trump,and given that Iran is unlikely to withdraw its military nuclear program under the existing security environment,the US and Israel ought to strengthen their nuclear deterrence capabilities against Iran.They need to issue clear,open,official retaliation commitments under a hypothetical nuclear scenario and bolster them with corresponding military and diplomatic capability.
文摘目的分析音乐治疗对卒中后认知障碍(post-stroke cognitive impairment,PSCI)患者的康复疗效,为PSCI患者的康复干预方法提供参考。方法前瞻性选取2020年12月-2022年7月在中国康复研究中心北京博爱医院住院并诊断为PSCI的患者,按照随机数字表法分为音乐治疗组和对照组。两组患者均给予神经内科常规药物治疗、护理以及常规康复治疗,音乐治疗组患者额外给予音乐治疗训练,两组均治疗1个月。治疗前后用蒙特利尔认知评估量表(Montreal Cognitive Assessment,MoCA)、美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)、Fugl-Meyer运动功能评定量表(Fugl-Meyer Assessment Scale,FMA)和改良巴氏指数评定量表(modified Barthel Index,MBI)评定患者的认知功能、神经功能缺损程度、运动功能和日常生活活动能力。结果共纳入48例患者,两组均为24例。两组患者的性别、年龄、受教育程度、卒中类型、病灶部位、合并疾病、心肌梗死或外周血管疾病病史、是否吸烟差异无统计学意义(P>0.05)。治疗前后两组大部分患者的语言和延迟回忆评分都不得分,差异无统计学意义(P>0.05)。两组患者治疗前MoCA评分、视空间与执行功能、命名、注意、计算、抽象思维和定向评分差异无统计学意义(P>0.05)。治疗后音乐治疗组的MoCA评分、视空间与执行功能、命名、注意、计算、抽象思维和定向评分较治疗前改善(P<0.05),治疗后对照组的MoCA评分、视空间与执行功能、命名、注意、定向评分较治疗前改善(P<0.05)。治疗后,音乐治疗组的MoCA评分[5.0(3.0,6.0)vs.2.5(1.0,4.0)分]、注意[1.0(0.0,1.0)vs.0.0(0.0,1.0)分]和抽象思维评分[0.0(0.0,1.0)vs.0.0(0.0,0.0)分]改善程度优于对照组(P<0.05)。两组患者治疗前NIHSS、FMA、MBI评分差异无统计学意义(P>0.05),治疗后均较治疗前改善(P<0.05)。治疗后,两组患者的NIHSS、FMA、MBI评分改善程度差异无统计学意义(P>0.05)。结论与常规康复治疗相比,结合了音乐治疗的训练对PSCI患者认知功能的改善更有益,特别是注意和抽象思维认知域,但对于神经功能缺损程度、肢体运动功能和日常生活活动能力的改善尚未发现显著优势。
基金supported by the National High Technology and Development Program of China (No.61971079)the Postgraduate Science Research Innovation Project of Chongqing Municipal Education Commission (No.CYS21319)。
文摘In order to reduce the high complexity of the successive cancellation list(SCL) algorithm for polar codes,a simplified SCL decoding algorithm based on critical sets(CS-SCL decoding algorithm) is proposed.The algorithm firstly constructs the critical sets according to the channel characteristics of the polar codes as well as comprehensively considering both the minimum Hamming weight(MHW) of the information bits and the channel reliability.The information bits within the critical sets and the path splitting are still performed by the SCL decoding algorithm while the information bits outside the critical sets are directly performed by the hard decision.Thus,the number of path ordering,copying,and deleting can be reduced during decoding.Furthermore,the computational complexity of the SCL decoding can also be reduced.Simulation results demonstrate that the decoding complexity of the proposed CS-SCL decoding algorithm,compared with the conventional SCL decoding algorithm,is reduced by at least 70%,while compared with the simplified SCL(PS-SS-SCL) algorithm which constructs the critical set with the first and second information bits of the Rate-1 nodes,its decoding complexity can also be reduced.Moreover,the loss of the error correction performance for the proposed CS-SCL decoding algorithm is minor.Therefore,the proposed CS-SCL algorithm is effective and can provide a reasonable tradeoff between the decoding performance and complexity for the decoding algorithm of polar codes.
