提出了一种基于梅尔频率倒谱系数(Mel frequency cepstrum coefficients,MFCC)的声音检测装置及算法实现。通过采集声音的波形,结合特征提取和分类算法,实现对不同声音的智能判断。从嵌入式系统硬件设计、声音波形特征提取、声音分类算...提出了一种基于梅尔频率倒谱系数(Mel frequency cepstrum coefficients,MFCC)的声音检测装置及算法实现。通过采集声音的波形,结合特征提取和分类算法,实现对不同声音的智能判断。从嵌入式系统硬件设计、声音波形特征提取、声音分类算法等方面进行了详细的研究,并对实验结果进行了分析。结果表明,该设计方案在声音检测方面具有较高的准确性和可行性。展开更多
This work is a simulation modelling with the LAMMPS calculation code of an electrode based on alkali metals (lithium, sodium and potassium) using the MEAM potential. For different multiplicities, two models were studi...This work is a simulation modelling with the LAMMPS calculation code of an electrode based on alkali metals (lithium, sodium and potassium) using the MEAM potential. For different multiplicities, two models were studied;with and without gap. In this work, we present the structural, physical and chemical properties of the lithium, sodium and potassium electrodes. For the structural properties, the cohesive energy and the mesh parameters were calculated, revealing that, whatever the chemical element selected, the compact hexagonal hcp structure is the most stable, followed by the face-centred cubic CFC structure, and finally the BCC structure. The most stable structure is lithium, with a cohesion energy of -6570 eV, and the lowest bcc-hcp transition energy of -0.553 eV/atom, followed by sodium. For physical properties, kinetic and potential energies were calculated for each of the sectioned chemical elements, with lithium achieving the highest value. Finally, for the chemical properties, we studied the diffusion coefficient and the activation energy. Only potassium followed an opposite order to the other two, with the quantities with lacunae being greater than those without lacunae, whatever the multiplicity. The order of magnitude of the diffusion coefficients is given by the relationship D<sub>Li</sub> > D<sub>Na</sub> > D<sub>k</sub> for the multiplicity 6*6*6, while for the activation energy the order is reversed.展开更多
Adaptive fractional polynomial modeling of general correlated outcomes is formulated to address nonlinearity in means, variances/dispersions, and correlations. Means and variances/dispersions are modeled using general...Adaptive fractional polynomial modeling of general correlated outcomes is formulated to address nonlinearity in means, variances/dispersions, and correlations. Means and variances/dispersions are modeled using generalized linear models in fixed effects/coefficients. Correlations are modeled using random effects/coefficients. Nonlinearity is addressed using power transforms of primary (untransformed) predictors. Parameter estimation is based on extended linear mixed modeling generalizing both generalized estimating equations and linear mixed modeling. Models are evaluated using likelihood cross-validation (LCV) scores and are generated adaptively using a heuristic search controlled by LCV scores. Cases covered include linear, Poisson, logistic, exponential, and discrete regression of correlated continuous, count/rate, dichotomous, positive continuous, and discrete numeric outcomes treated as normally, Poisson, Bernoulli, exponentially, and discrete numerically distributed, respectively. Example analyses are also generated for these five cases to compare adaptive random effects/coefficients modeling of correlated outcomes to previously developed adaptive modeling based on directly specified covariance structures. Adaptive random effects/coefficients modeling substantially outperforms direct covariance modeling in the linear, exponential, and discrete regression example analyses. It generates equivalent results in the logistic regression example analyses and it is substantially outperformed in the Poisson regression case. Random effects/coefficients modeling of correlated outcomes can provide substantial improvements in model selection compared to directly specified covariance modeling. However, directly specified covariance modeling can generate competitive or substantially better results in some cases while usually requiring less computation time.展开更多
The new independent solutions of the nonlinear differential equation with time-dependent coefficients (NDE-TC) are discussed, for the first time, by employing experimental device called a drinking bird whose simple ba...The new independent solutions of the nonlinear differential equation with time-dependent coefficients (NDE-TC) are discussed, for the first time, by employing experimental device called a drinking bird whose simple back-and-forth motion develops into water drinking motion. The solution to a drinking bird equation of motion manifests itself the transition from thermodynamic equilibrium to nonequilibrium irreversible states. The independent solution signifying a nonequilibrium thermal state seems to be constructed as if two independent bifurcation solutions are synthesized, and so, the solution is tentatively termed as the bifurcation-integration solution. The bifurcation-integration solution expresses the transition from mechanical and thermodynamic equilibrium to a nonequilibrium irreversible state, which is explicitly shown by the nonlinear differential equation with time-dependent coefficients (NDE-TC). The analysis established a new theoretical approach to nonequilibrium irreversible states, thermomechanical dynamics (TMD). The TMD method enables one to obtain thermodynamically consistent and time-dependent progresses of thermodynamic quantities, by employing the bifurcation-integration solutions of NDE-TC. We hope that the basic properties of bifurcation-integration solutions will be studied and investigated further in mathematics, physics, chemistry and nonlinear sciences in general.展开更多
现今关于驾驶员路怒情绪识别方法中语音特性分析相对较少,该研究以路怒情绪为研究对象,利用模拟驾驶系统建立数据集,通过分析驾驶员语音的频谱特征,将时域中短时能量及短时过零率特征参数和改进Mel频率倒谱系数(Mel frequency cepstral ...现今关于驾驶员路怒情绪识别方法中语音特性分析相对较少,该研究以路怒情绪为研究对象,利用模拟驾驶系统建立数据集,通过分析驾驶员语音的频谱特征,将时域中短时能量及短时过零率特征参数和改进Mel频率倒谱系数(Mel frequency cepstral coefficients,MFCC)特征参数融合构成特征参数向量,利用萤火虫算法(firefly algorithm,FA)优化PNN神经网络(probabilistic neural networks)并构建识别模型,实现驾驶员路怒情绪的识别。实验结果表明,在相同神经网络下,改进MFCC融合特征提取方法相比传统MFCC特征提取方法具有更好的抗噪性。同时,FA-PNN模型的识别准确率为93.0%,相比传统PNN模型提高了11个百分点;F1-Score值为0.9328,提高了0.1047。该研究论证了语音信号处理技术对驾驶员路怒情绪识别的可行性,为汽车主动安全驾驶预警研究提供了新方法。展开更多
针对单一传统方法对歌声分离不彻底的问题,文章提出了一种基于鲁棒主成分分析(Robust Principal Component Analysis,RPCA)和梅尔频率倒谱系数(Mel Frequency Cepstrum Coefficients,MFCC)反复结构的两步歌声伴奏分离模型。该模型有效...针对单一传统方法对歌声分离不彻底的问题,文章提出了一种基于鲁棒主成分分析(Robust Principal Component Analysis,RPCA)和梅尔频率倒谱系数(Mel Frequency Cepstrum Coefficients,MFCC)反复结构的两步歌声伴奏分离模型。该模型有效地改善了鲁棒主成分分析对歌声分离不完全和梅尔频率倒谱系数反复结构歌声在低频处分离不佳的问题。首先使用鲁棒主成分分析将混合音乐信号分解为低秩矩阵和稀疏矩阵,然后分别对其提取梅尔频率倒谱系数特征参数并且对其进行相似运算,构建相似矩阵及建立梅尔频率倒谱系数反复结构模型并通过反复结构模型分别得到低秩矩阵和稀疏矩阵相关的掩蔽矩阵,最后根据构建的掩蔽矩阵模型以及傅里叶逆变换得到背景音乐和歌声。在公开数据集上进行了实验,实验结果表明本文算法在歌声分离性能上与比较算法相比,平均信号干扰比值最高有接近7 dB的提高。展开更多
文摘提出了一种基于梅尔频率倒谱系数(Mel frequency cepstrum coefficients,MFCC)的声音检测装置及算法实现。通过采集声音的波形,结合特征提取和分类算法,实现对不同声音的智能判断。从嵌入式系统硬件设计、声音波形特征提取、声音分类算法等方面进行了详细的研究,并对实验结果进行了分析。结果表明,该设计方案在声音检测方面具有较高的准确性和可行性。
文摘This work is a simulation modelling with the LAMMPS calculation code of an electrode based on alkali metals (lithium, sodium and potassium) using the MEAM potential. For different multiplicities, two models were studied;with and without gap. In this work, we present the structural, physical and chemical properties of the lithium, sodium and potassium electrodes. For the structural properties, the cohesive energy and the mesh parameters were calculated, revealing that, whatever the chemical element selected, the compact hexagonal hcp structure is the most stable, followed by the face-centred cubic CFC structure, and finally the BCC structure. The most stable structure is lithium, with a cohesion energy of -6570 eV, and the lowest bcc-hcp transition energy of -0.553 eV/atom, followed by sodium. For physical properties, kinetic and potential energies were calculated for each of the sectioned chemical elements, with lithium achieving the highest value. Finally, for the chemical properties, we studied the diffusion coefficient and the activation energy. Only potassium followed an opposite order to the other two, with the quantities with lacunae being greater than those without lacunae, whatever the multiplicity. The order of magnitude of the diffusion coefficients is given by the relationship D<sub>Li</sub> > D<sub>Na</sub> > D<sub>k</sub> for the multiplicity 6*6*6, while for the activation energy the order is reversed.
文摘Adaptive fractional polynomial modeling of general correlated outcomes is formulated to address nonlinearity in means, variances/dispersions, and correlations. Means and variances/dispersions are modeled using generalized linear models in fixed effects/coefficients. Correlations are modeled using random effects/coefficients. Nonlinearity is addressed using power transforms of primary (untransformed) predictors. Parameter estimation is based on extended linear mixed modeling generalizing both generalized estimating equations and linear mixed modeling. Models are evaluated using likelihood cross-validation (LCV) scores and are generated adaptively using a heuristic search controlled by LCV scores. Cases covered include linear, Poisson, logistic, exponential, and discrete regression of correlated continuous, count/rate, dichotomous, positive continuous, and discrete numeric outcomes treated as normally, Poisson, Bernoulli, exponentially, and discrete numerically distributed, respectively. Example analyses are also generated for these five cases to compare adaptive random effects/coefficients modeling of correlated outcomes to previously developed adaptive modeling based on directly specified covariance structures. Adaptive random effects/coefficients modeling substantially outperforms direct covariance modeling in the linear, exponential, and discrete regression example analyses. It generates equivalent results in the logistic regression example analyses and it is substantially outperformed in the Poisson regression case. Random effects/coefficients modeling of correlated outcomes can provide substantial improvements in model selection compared to directly specified covariance modeling. However, directly specified covariance modeling can generate competitive or substantially better results in some cases while usually requiring less computation time.
文摘The new independent solutions of the nonlinear differential equation with time-dependent coefficients (NDE-TC) are discussed, for the first time, by employing experimental device called a drinking bird whose simple back-and-forth motion develops into water drinking motion. The solution to a drinking bird equation of motion manifests itself the transition from thermodynamic equilibrium to nonequilibrium irreversible states. The independent solution signifying a nonequilibrium thermal state seems to be constructed as if two independent bifurcation solutions are synthesized, and so, the solution is tentatively termed as the bifurcation-integration solution. The bifurcation-integration solution expresses the transition from mechanical and thermodynamic equilibrium to a nonequilibrium irreversible state, which is explicitly shown by the nonlinear differential equation with time-dependent coefficients (NDE-TC). The analysis established a new theoretical approach to nonequilibrium irreversible states, thermomechanical dynamics (TMD). The TMD method enables one to obtain thermodynamically consistent and time-dependent progresses of thermodynamic quantities, by employing the bifurcation-integration solutions of NDE-TC. We hope that the basic properties of bifurcation-integration solutions will be studied and investigated further in mathematics, physics, chemistry and nonlinear sciences in general.
文摘针对单一传统方法对歌声分离不彻底的问题,文章提出了一种基于鲁棒主成分分析(Robust Principal Component Analysis,RPCA)和梅尔频率倒谱系数(Mel Frequency Cepstrum Coefficients,MFCC)反复结构的两步歌声伴奏分离模型。该模型有效地改善了鲁棒主成分分析对歌声分离不完全和梅尔频率倒谱系数反复结构歌声在低频处分离不佳的问题。首先使用鲁棒主成分分析将混合音乐信号分解为低秩矩阵和稀疏矩阵,然后分别对其提取梅尔频率倒谱系数特征参数并且对其进行相似运算,构建相似矩阵及建立梅尔频率倒谱系数反复结构模型并通过反复结构模型分别得到低秩矩阵和稀疏矩阵相关的掩蔽矩阵,最后根据构建的掩蔽矩阵模型以及傅里叶逆变换得到背景音乐和歌声。在公开数据集上进行了实验,实验结果表明本文算法在歌声分离性能上与比较算法相比,平均信号干扰比值最高有接近7 dB的提高。
