oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 136 )

2018 ( 1120 )

2017 ( 1096 )

2016 ( 979 )

Custom range...

Search Results: 1 - 10 of 79220 matches for " ZHAO Zhi-jin "
All listed articles are free for downloading (OA Articles)
Page 1 /79220
Display every page Item
Algorithm for underdetermined blind signal separation based on constrained NMF
基于约束NMF的欠定盲信号分离算法*

ZHAO Zhi-jin,LU Hong,SHANG Jun-na,
赵知劲
,卢宏,尚俊娜

计算机应用研究 , 2011,
Abstract: A constrained nonnegative matrix factorization (NMF) method is proposed to resolve the problem of underdetermined blind signal separation in this paper. It is hard to obtain unique factorization and correctly separate source signals when NMF is directly applied to resolve problem above. In this paper, on the basis of standard NMF, determinant criterion was imposed on estimated mixing matrix to achieve the unique factorization of NMF; sparsity and the least correlated component constraints was imposed on estimated sources to realize the unique separation of mixed signals and improve the performance of source separation. Simulation results show effectiveness of the proposed algorithm.
Cognitive radio decision engine based on binary particle swarm optimization
基于二进制粒子群算法的认知无线电决策引擎

Zhao Zhi-Jin,Xu Shi-Yu,Zheng Shi-Lian,Yang Xiao-Niu,
赵知劲
,徐世宇,郑仕链,杨小牛

物理学报 , 2009,
Abstract: Cognitive radio decision engine based on particle swarm optimization is proposed. A population adaptive particle swarm optimization is also proposed to improve the convergence rate. Particle swarm optimization and population adaptive particle swarm optimization are used to adapt radio parameters respectively, and multi-carrier system is used for the performance analysis. Results show that cognitive decision engine based on binary particle swarm optimization has better convergence, precision and stability than the classic genetic algorithm, and population adaptive particle swarm optimization can further improve the performance at the initial stage of the search to meet real time requirement of cognitive radio.
Speech Emotion Recognition Based on an Improved Supervised Manifold Learning Algorithm
基于一种改进的监督流形学习算法的语音情感识别

Zhang Shi-qing Li Le-min Zhao Zhi-jin,
张石清
,李乐民,赵知劲

电子与信息学报 , 2010,
Abstract: To improve effectively the performance on speech emotion recognition, it is needed to perform nonlinear dimensionality reduction for speech feature data lying on a nonlinear manifold embedded in high-dimensional acoustic space. Supervised Locally Linear Embedding (SLLE) is a typical supervised manifold learning algorithm for nonlinear dimensionality reduction. Considering the existing drawbacks of SLLE, this paper proposes an improved version of SLLE, which enhances the discriminating power of low-dimensional embedded data and possesses the optimal generalization ability. The proposed algorithm is used to conduct nonlinear dimensionality reduction for 48-dimensional speech emotional feature data including prosody and voice quality features, and extract low-dimensional embedded discriminating features so as to recognize four emotions including anger, joy, sadness and neutral. Experimental results on the natural speech emotional database demonstrate that the proposed algorithm obtains the highest accuracy of 90.78% with only less 9 embedded features, making 15.65% improvement over SLLE. Therefore, the proposed algorithm can significantly improve speech emotion recognition results when applied for reducing dimensionality of speech emotional feature data.
A Numerical Simulation on Torrential Rain During the Meiyu Period and Analysis of Mesoscale and Microscale Structure of Convective Systems
梅雨期暴雨个例模拟及其中小尺度结构特征分析研究

SUN Jing,LOU Xiao-Feng,HU Zhi-Jin,ZHAO Si-Xiong,
孙晶
,楼小凤,胡志晋,赵思雄

大气科学 , 2007,
Abstract: 利用中尺度数值模式MM5和多普勒雷达观测资料,对2002年7月22~23日发生在长江中游一次梅雨暴雨过程进行模拟和分析。模拟结果与观测资料相比基本吻合。主要研究内容包括暴雨过程α中尺度到γ中尺度的回波结构以及动力特征和云降水粒子的分布。研究结果表明:在长江中游地区存在一条东北西南走向低空切变线,切变线北侧偏东气流中回波较弱,而南侧西南气流中不断出现强对流云团发生发展、合并分裂现象,形成沿着切变线分布的α中尺度对流带。对流带中有多个东北西南向的β中尺度波列,这些波列由从西南向东北方向移动的γ中尺度回波所构成。新回波大多产生在老回波的后部。γ中尺度回波具有相应尺度的气流辐合辐散结构。各种云降水粒子与动力场相互配合,上升运动位置和强弱决定云水的位置和强弱。云发展初期降雨首先产生于低层,以暖雨过程为主,成熟期云中冰相粒子对降水非常重要。强回波区的降水会在近地面产生出流。在西南气流中,远离切变线的回波移速大于靠近切变线的回波,容易产生回波合并;强回波由于降水而产生下沉和辐散气流,易导致回波分裂。
Wideband spectrum sensing approach based on multiband signal sampling and wavelet transform
基于多子带信号采样和小波变换的宽带频谱感知*

ZHAO Zhi-jin,ZHANG Wei-wei,ZHENG Shi-lian,
赵知劲
,张伟卫,郑仕链

计算机应用研究 , 2011,
Abstract: In GHz-level wideband spectrum sensing, too high sampling rate exceeds the specifications of existed analog-to-digital converters (ADC) by sampling directly. Moreover, an accurate estimate of occupied spectrum band can improve spectrum utilization. Therefore, with modulated wideband converter (MWC), a wideband spectrum sensing approach based on multiband signal sampling and wavelet transform is proposed in this paper. With MWC, sub-bands signals are firstly obtained by low rate sampling; and then, an estimation method for noise power and threshold is proposed, such that the spectrum sensing for signal sub-bands can be carried out by energy detection; at last, the edge detection for signal sub-bands by using wavelet transform is used to obtain the exact locations of spectrum occupied by primary users. Simulation results show that the proposed wideband spectrum sensing approach is feasible and effective.
梅雨期暴雨个例模拟及其中小尺度结构特征分析研究
孙晶 SUN Jing,楼小凤 LOU Xiao-Feng,胡志晋 HU Zhi-Jin,赵思雄 ZHAO Si-Xiong
大气科学 , 2007, DOI: 10.3878/j.issn.1006-9895.2007.01.01
Abstract: 利用中尺度数值模式MM5和多普勒雷达观测资料,对2002年7月22~23日发生在长江中游一次梅雨暴雨过程进行模拟和分析。模拟结果与观测资料相比基本吻合。主要研究内容包括暴雨过程α中尺度到γ中尺度的回波结构以及动力特征和云降水粒子的分布。研究结果表明:在长江中游地区存在一条东北西南走向低空切变线,切变线北侧偏东气流中回波较弱,而南侧西南气流中不断出现强对流云团发生发展、合并分裂现象,形成沿着切变线分布的α中尺度对流带。对流带中有多个东北西南向的β中尺度波列,这些波列由从西南向东北方向移动的γ中尺度回波所构成。新回波大多产生在老回波的后部。γ中尺度回波具有相应尺度的气流辐合辐散结构。各种云降水粒子与动力场相互配合,上升运动位置和强弱决定云水的位置和强弱。云发展初期降雨首先产生于低层,以暖雨过程为主,成熟期云中冰相粒子对降水非常重要。强回波区的降水会在近地面产生出流。在西南气流中,远离切变线的回波移速大于靠近切变线的回波,容易产生回波合并;强回波由于降水而产生下沉和辐散气流,易导致回波分裂。
On the Time Step of Semi-Lagrangian Semi-Implicit Atmospheric Model
关于半拉格朗日半隐式大气模式的时步问题

HU Zhi-Jin,HU Zhi-Jin,
胡志晋
,史月琴

大气科学 , 2006,
Abstract: 讨论半拉格朗日半隐式大气模式中时步的限制,展示时步过大时用一般的首尾两点平均方案计算非线性源汇项的严重误差,提出精确的源汇项计算格式并作了特例计算和比较,讨论了被模拟的大气过程和波动的特征对时步的要求,指出柯朗数NC=C.Δt/ΔX是大气模式时空步长匹配的重要参数。指出云降水和大气化学过程特征时间对相应的正定变量的计算时步的限制。
关于半拉格朗日半隐式大气模式的时步问题
胡志晋 HU Zhi-Jin,史月琴 HU Zhi-Jin
大气科学 , 2006, DOI: 10.3878/j.issn.1006-9895.2006.01.01
Abstract: 讨论半拉格朗日半隐式大气模式中时步的限制,展示时步过大时用一般的首尾两点平均方案计算非线性源汇项的严重误差,提出精确的源汇项计算格式并作了特例计算和比较,讨论了被模拟的大气过程和波动的特征对时步的要求,指出柯朗数NC=C·△t/△X是大气模式时空步长匹配的重要参数.指出云降水和大气化学过程特征时间对相应的正定变量的计算时步的限制.
Cognitive radio spectrum assignment based on quantum genetic algorithm
基于量子遗传算法的认知无线电频谱分配

Zhao Zhi-Jin,Peng Zhen,Zheng Shi-Lian,Xu Shi-Yu,Lou Cai-Yi,Yang Xiao-Niu,
赵知劲
,彭振,郑仕链,徐世宇,楼才义,杨小牛

物理学报 , 2009,
Abstract: Cognitive radio spectrum assignment based on quantum genetic algorithm is proposed, and simulations are conducted to compare the proposed method with color sensitive graph coloring algorithm. Results show that the proposed method greatly outperforms the color sensitive graph coloring algorithm as it better optimizes network utilization. The proposed method can find the optimal solutions after only several generations, while the relative differences between solutions obtained by color sensitive graph coloring algorithm and the optimal solutions are quite large.
A study of cognitive radio decision engine based on quantum genetic algorithm
基于量子遗传算法的认知无线电决策引擎研究

Zhao Zhi-Jin,Zheng Shi-Lian,Shang Jun-Na,Kong Xian-Zheng,
赵知劲
,郑仕链,尚俊娜,孔宪正

物理学报 , 2007,
Abstract: One of the basic capabilities of cognitive radio is to adapt the radio parameters according to the changing environment and user needs. A cognitive radio decision engine based on quantum genetic algorithm is proposed, in which the radio parameters are adapted and optimized by quantum genetic algorithm. The multiple objective functions are designed and multi-carrier system is used for performance analysis. Experimental results show that the proposed method has better convergence, precision and stability than the classic genetic algorithm, and the good performance of the proposed method in small population size illustrates that it is suitable for hardware implementation. Simulation results under different weighting scenarios illustrate the trade-off between multiple objective functions and that the adapted parameter configuration is consistent with the weights of the objective functions.
Page 1 /79220
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.