采用键盘敲击任务探讨学习者主观估计错误活动、结果反馈时机(knowledge of results,简称KR)对运动技能学习的影响。抽取90名右利手的在校大学生,随机分为:主观估计无KR组、主观估计及时KR组、主观估计延迟KR组,算术活动无KR组,算术活...采用键盘敲击任务探讨学习者主观估计错误活动、结果反馈时机(knowledge of results,简称KR)对运动技能学习的影响。抽取90名右利手的在校大学生,随机分为:主观估计无KR组、主观估计及时KR组、主观估计延迟KR组,算术活动无KR组,算术活动及时KR组,算术活动延迟KR组(组间性别均衡设计)。主观估计错误活动组在练习间以口头报告的形式评估自己刚才操作总时间的误差,算术活动组按照实验员的要求进行数字算术口头运算。无KR组不提供KR,及时KR组在主观估计错误活动或算术活动后即刻获得KR,延迟KR组则延迟4s获得KR。第1-2天,6组受试者在各自的条件下分别练习,每天练习108次。第3天,练习后,休息10min,使用原任务进行保持测试10次,要求受试者每次测试后口头报告自己操作的总时间。第4天,使用原任务进行保持测试10次,要求受试者每次测试后口头报告自己操作的总时间。结果显示:(1)练习后从事主观估计错误活动,并能及时获得KR的学习者,保持测试的绩效最好;(2)主观估计错误活动影响提供KR的适宜时机。展开更多
在大规模多输入多输出(Massive-Multiple Input and Multiple-Output,mMIMO)系统中,叠加信道状态信息(Channel State Information,CSI)反馈可避免上行带宽资源占用,但叠加干扰会造成接收机计算复杂度高、反馈精度低等问题,且均未考虑存...在大规模多输入多输出(Massive-Multiple Input and Multiple-Output,mMIMO)系统中,叠加信道状态信息(Channel State Information,CSI)反馈可避免上行带宽资源占用,但叠加干扰会造成接收机计算复杂度高、反馈精度低等问题,且均未考虑存在CSI估计错误的实际应用场景。为此,针对存在CSI估计错误场景下的叠加CSI反馈,在改进极限学习机(Extreme Learning Machine,ELM)的基础上,提出基于增强型ELM的叠加CSI反馈方法。首先,基站对接收信号进行预均衡处理,初步消除上行信道干扰;然后对传统叠加CSI反馈进行迭代展开,构建增强型ELM网络,通过规范化各个ELM网络的隐藏层输出来增强网络学习数据分布的能力,从而改善恢复下行CSI和上行用户数据序列(Uplink User Data Sequence,UL-US)的精确性。仿真实验表明,与经典和时新的叠加CSI反馈方法相比,所提方法能够获得相似或更好的下行CSI和上行用户数据的恢复精确性;同时,针对不同的参数影响,性能改善具有鲁棒性。展开更多
In the Davey-MacKay(DM) construction,the inner decoder treats unknown transmitted bits as random independent substitution errors. It limits the synchronization capability of the inner decoder, and thus weakens the err...In the Davey-MacKay(DM) construction,the inner decoder treats unknown transmitted bits as random independent substitution errors. It limits the synchronization capability of the inner decoder, and thus weakens the error-correcting capability of the DM construction.In order to improve the performance of the DM construction, an iterative decoding scheme is proposed, which iteratively utilizes the more accurate estimates of transmitted codewords. In the proposed scheme, the estimated average bit error rates and the estimated low-density parity-check(LDPC) codewords from the outer decoder are fed back into the inner decoder to update the synchronization process. Simulation results show that the proposed iterative decoding scheme significantly outperforms the traditional DM construction.展开更多
Significant wave height is an important criterion in designing coastal and offshore structures.Based on the orthogonality principle, the linear mean square estimation method is applied to calculate significant wave he...Significant wave height is an important criterion in designing coastal and offshore structures.Based on the orthogonality principle, the linear mean square estimation method is applied to calculate significant wave height in this paper.Twenty-eight-year time series of wave data collected from three ocean buoys near San Francisco along the California coast are analyzed.It is proved theoretically that the computation error will be reduced by using as many measured data as possible for the calculation of significant wave height.Measured significant wave height at one buoy location is compared with the calculated value based on the data from two other adjacent buoys.The results indicate that the linear mean square estimation method can be well applied to the calculation and prediction of significant wave height in coastal regions.展开更多
H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and unique...H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and uniqueness of semidiscrete solutions are derived for problems in one space dimension.And the methods don＇t require the LBB condition.展开更多
文摘采用键盘敲击任务探讨学习者主观估计错误活动、结果反馈时机(knowledge of results,简称KR)对运动技能学习的影响。抽取90名右利手的在校大学生,随机分为:主观估计无KR组、主观估计及时KR组、主观估计延迟KR组,算术活动无KR组,算术活动及时KR组,算术活动延迟KR组(组间性别均衡设计)。主观估计错误活动组在练习间以口头报告的形式评估自己刚才操作总时间的误差,算术活动组按照实验员的要求进行数字算术口头运算。无KR组不提供KR,及时KR组在主观估计错误活动或算术活动后即刻获得KR,延迟KR组则延迟4s获得KR。第1-2天,6组受试者在各自的条件下分别练习,每天练习108次。第3天,练习后,休息10min,使用原任务进行保持测试10次,要求受试者每次测试后口头报告自己操作的总时间。第4天,使用原任务进行保持测试10次,要求受试者每次测试后口头报告自己操作的总时间。结果显示:(1)练习后从事主观估计错误活动,并能及时获得KR的学习者,保持测试的绩效最好;(2)主观估计错误活动影响提供KR的适宜时机。
文摘在大规模多输入多输出(Massive-Multiple Input and Multiple-Output,mMIMO)系统中,叠加信道状态信息(Channel State Information,CSI)反馈可避免上行带宽资源占用,但叠加干扰会造成接收机计算复杂度高、反馈精度低等问题,且均未考虑存在CSI估计错误的实际应用场景。为此,针对存在CSI估计错误场景下的叠加CSI反馈,在改进极限学习机(Extreme Learning Machine,ELM)的基础上,提出基于增强型ELM的叠加CSI反馈方法。首先,基站对接收信号进行预均衡处理,初步消除上行信道干扰;然后对传统叠加CSI反馈进行迭代展开,构建增强型ELM网络,通过规范化各个ELM网络的隐藏层输出来增强网络学习数据分布的能力,从而改善恢复下行CSI和上行用户数据序列(Uplink User Data Sequence,UL-US)的精确性。仿真实验表明,与经典和时新的叠加CSI反馈方法相比,所提方法能够获得相似或更好的下行CSI和上行用户数据的恢复精确性;同时,针对不同的参数影响,性能改善具有鲁棒性。
基金supported in part by National Natural Science Foundation of China(61671324)the Director’s Funding from Qingdao National Laboratory for Marine Science and Technology
文摘In the Davey-MacKay(DM) construction,the inner decoder treats unknown transmitted bits as random independent substitution errors. It limits the synchronization capability of the inner decoder, and thus weakens the error-correcting capability of the DM construction.In order to improve the performance of the DM construction, an iterative decoding scheme is proposed, which iteratively utilizes the more accurate estimates of transmitted codewords. In the proposed scheme, the estimated average bit error rates and the estimated low-density parity-check(LDPC) codewords from the outer decoder are fed back into the inner decoder to update the synchronization process. Simulation results show that the proposed iterative decoding scheme significantly outperforms the traditional DM construction.
基金support for this study was provided by the National Natural Science Foundation of China (No.40776006)Research Fund for the Doctoral Program of Higher Education of China (Grant No.20060423009)the Science and Technology Development Program of Shandong Province (Grant No.2008GGB01099)
文摘Significant wave height is an important criterion in designing coastal and offshore structures.Based on the orthogonality principle, the linear mean square estimation method is applied to calculate significant wave height in this paper.Twenty-eight-year time series of wave data collected from three ocean buoys near San Francisco along the California coast are analyzed.It is proved theoretically that the computation error will be reduced by using as many measured data as possible for the calculation of significant wave height.Measured significant wave height at one buoy location is compared with the calculated value based on the data from two other adjacent buoys.The results indicate that the linear mean square estimation method can be well applied to the calculation and prediction of significant wave height in coastal regions.
基金Supported by NNSF(10601022,11061021)Supported by NSF of Inner Mongolia Au-tonomous Region(200607010106)Supported by SRP of Higher Schools of Inner Mongolia(NJ10006)
文摘H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and uniqueness of semidiscrete solutions are derived for problems in one space dimension.And the methods don＇t require the LBB condition.
