Creatinine(Cr)is a biochemical waste molecule generated from muscle metabolism and primarily cleared from the bloodstream by the kidneys.If kidney function declines,Cr levels in the blood tend to increase.Therefore,Cr...Creatinine(Cr)is a biochemical waste molecule generated from muscle metabolism and primarily cleared from the bloodstream by the kidneys.If kidney function declines,Cr levels in the blood tend to increase.Therefore,Cr serves as an indicator of kidney function.In this work,we present a simple method for the rapid screening for impaired renal function based on the subject's Cr concentration.In our setup,broadband white light is delivered to a finger clamp through a fiber-optic cable to illuminate the patient's finger.The light is transmitted through the finger and collected by a second optical fiber coupled to a visible-near-infrared(VisNIR)spectrometer which covers the spectral range from 400nm to 1100nm.During the calibration process,the transmitted spectra acquired from 60 patients were measured.An average was calculated using the peak level of the transmitted,diffused intensity at three different wavelengths to create a"Cr intensity index".Patients were divided into five groups according to their Cr concentration levels,ranging from 1 mg/dL to 13 mg/dL.Our observations indicated that each group featured a unique spectral fingerprint.Next,we tested the index on 20 patients not included in the cali-bration procedure(unknown samples).We were able to classify patients into groups according to their Cr level with moderate prediction accuracy(R^(2)=0.55)and mean screening error of up to 16%.Future efforts will evaluate the accuracy of this approach with larger patient populations representing a broad range of Cr concentration.Still,this preliminary work is an essential step toward developing this useful noninvasive Cr screening platform using NIR light spectroscopy.展开更多
In this work two different fluorochromes （Alexa 594 and Alexa 680） are conjugated to the same monoclonal antibody （Cetuximab） for obtaining a characteristic M-shaped dual-peak spectrum. Dual-labeling of Cetuximab ...In this work two different fluorochromes （Alexa 594 and Alexa 680） are conjugated to the same monoclonal antibody （Cetuximab） for obtaining a characteristic M-shaped dual-peak spectrum. Dual-labeling of Cetuximab by mixing both fluorochromes before the conjugation step gives spectral results similar to those of mixing of fluorochrome-labeled Cetuximab after the conjugation step （P 〉 0.05）. In conclusion, both methods may be used equivalently for producing a dual-labeled single-antibody probe. Future studies may test whether the M-shaped spectrum may increase the diagnostic confidence in tumor-targeted multispectral optical imaging.展开更多
High peak-to-average-power ratio(PAPR) and spectral leakage are two main drawbacks of multicarrier systems, such as in orthogonal frequency division multiplexing(OFDM), in future 5G wireless communications. For genera...High peak-to-average-power ratio(PAPR) and spectral leakage are two main drawbacks of multicarrier systems, such as in orthogonal frequency division multiplexing(OFDM), in future 5G wireless communications. For generating optimized wave forms for 5G communications, this paper proposes an iterative scheme combining time-domain N-continuous OFDM(TD-NC-OFDM) and serial peak cancellation(SPC). Based on the theory of projection onto convex sets(POCS), the effectiveness of the proposed scheme is proved, and the optimized time-frequency domain multicarrier waveforms are analyzed in terms of a balanced tradeoff between out-of-band spectral leakage and PAPR. Both theoretical analysis and simulation results show that the proposed scheme can jointly optimize both the PAPR and out-ofband radiation, with moderate computational complexity.展开更多
High field asymmetric wave ion mobility spectrometry （FAIMS） is a powerful tool to detect and characterize gas-phase ions, while the unsolvable partial differential equation of ions moving in ion drift tube poses a ...High field asymmetric wave ion mobility spectrometry （FAIMS） is a powerful tool to detect and characterize gas-phase ions, while the unsolvable partial differential equation of ions moving in ion drift tube poses a big challenge to FAIMS spectral peak analysis. In this work, a universal and effective model of FAIMS spectral peak profile has been proposed by introducing ion trajectory and loss height. With this model, the influence of the structure of ion drift tube, dispersion voltages, compensation voltages, and carrier gas flow rate on the FAIMS spectral peak characteristics like peak shape, full width at half maximum and peak height is analyzed and discussed. The results show that the influence of different factors on the FAIMS spectral peak profile can be qualitatively described by the model which agrees with the experimental data.展开更多
This study evaluates the capability of the Simulating WAves Nearshore(SWAN)wave model(version 41.01)in predicting significant wave height and spectral peak energy content for swell waves in very shallow water of surf ...This study evaluates the capability of the Simulating WAves Nearshore(SWAN)wave model(version 41.01)in predicting significant wave height and spectral peak energy content for swell waves in very shallow water of surf zone during depth-induced wave breaking and dissipation.The model results were compared with field measurements at five nearshore stations.The results demonstrated that some breaker index formulations were successful for significant wave height prediction in surf zones.However,an incorrect shape of the energy spectrum and overestimated near spectral peak energy content at shallow water stations were obtained using all of the embedded depth-induced wave breaking formulations in SWAN.The dependent breaker index on relative depth(Kpd)formulation,which was successful in predicting near spectral peak energy content,resulted in an average error of 30%.Finally,this formulation was modified to enhance the model performance in reproducing the spectral peak energy content.展开更多
针对谱聚类在尺度参数计算时需要人为设置近邻参数及聚类结果不稳定等问题,本文将初始类中心值和尺度参数作为决策变量,重点对谱聚类算法进行自适应优化与改进。首先,将样本邻域标准差的倒数作为度量样本局部密度的参数,与密度峰值思想...针对谱聚类在尺度参数计算时需要人为设置近邻参数及聚类结果不稳定等问题,本文将初始类中心值和尺度参数作为决策变量,重点对谱聚类算法进行自适应优化与改进。首先,将样本邻域标准差的倒数作为度量样本局部密度的参数,与密度峰值思想相结合,设计了一种基于密度峰值的初始类中心决策值选择方法(initial class center decision value algorithm based on density peak,DP_KD),解决密度调整谱聚类中聚类结果不稳定的问题。其次,利用样本间的平均距离计算相应的邻域半径,并根据样本标准差自适应地求解每个样本的尺度参数,构造样本间的相似度矩阵,实现了近邻参数的自适应设置,解决尺度参数需要人为设置的问题。然后,基于优化后的初始类中心决策值和近邻参数方法,进一步调整高斯核函数,提出一种基于邻域标准差的密度调整谱聚类算法(density adjusted spectral clustering algorithm based on neighborhood standard deviation,DSSD),通过构建特征向量空间实现了密度谱聚类。最后,将提出的算法与其他聚类算法在多个数据集上进行了对比。结果表明,与其他谱聚类算法相比,本文提出的DSSD算法不仅具有更好的聚类效果,且聚类结果更加稳定,尤其是在类内密集且类间边缘明确的DIM512数据集中,DSSD算法可以正确地进行聚类分簇;在准确率、兰德系数和F-measure上较其他算法至少提升了0.0268、0.0136和0.0247,这表明DSSD算法不仅聚类效果较好且更适合大规模数据集的聚类分析。展开更多
频谱兼容波形利用多段离散寂静带宽合成大带宽,在满足带宽要求的同时有效对抗频域密集干扰。为了抑制频谱兼容波形的峰值旁瓣水平,提出一种低峰值旁瓣频谱兼容波形设计方案。所提方案综合考虑波形的自相关峰值旁瓣性能和抗干扰性能,构...频谱兼容波形利用多段离散寂静带宽合成大带宽,在满足带宽要求的同时有效对抗频域密集干扰。为了抑制频谱兼容波形的峰值旁瓣水平,提出一种低峰值旁瓣频谱兼容波形设计方案。所提方案综合考虑波形的自相关峰值旁瓣性能和抗干扰性能,构建加权目标函数。在波形恒模约束下,该问题为非确定多项式难(non-deterministic polynomial-hard,NP-hard)问题。为此,首先利用指数对数平滑技术逼近目标函数,进而提出基于快速傅里叶变换的共轭梯度(conjugate gradient method based on fast Fourier transformation,CGFFT)法求解该问题。此外,波形设计中需要根据性能指标要求选择合适的加权值,为此提出一种加权值自适应确定方法,最后通过数值仿真验证了所提方法的有效性。展开更多
文摘Creatinine(Cr)is a biochemical waste molecule generated from muscle metabolism and primarily cleared from the bloodstream by the kidneys.If kidney function declines,Cr levels in the blood tend to increase.Therefore,Cr serves as an indicator of kidney function.In this work,we present a simple method for the rapid screening for impaired renal function based on the subject's Cr concentration.In our setup,broadband white light is delivered to a finger clamp through a fiber-optic cable to illuminate the patient's finger.The light is transmitted through the finger and collected by a second optical fiber coupled to a visible-near-infrared(VisNIR)spectrometer which covers the spectral range from 400nm to 1100nm.During the calibration process,the transmitted spectra acquired from 60 patients were measured.An average was calculated using the peak level of the transmitted,diffused intensity at three different wavelengths to create a"Cr intensity index".Patients were divided into five groups according to their Cr concentration levels,ranging from 1 mg/dL to 13 mg/dL.Our observations indicated that each group featured a unique spectral fingerprint.Next,we tested the index on 20 patients not included in the cali-bration procedure(unknown samples).We were able to classify patients into groups according to their Cr level with moderate prediction accuracy(R^(2)=0.55)and mean screening error of up to 16%.Future efforts will evaluate the accuracy of this approach with larger patient populations representing a broad range of Cr concentration.Still,this preliminary work is an essential step toward developing this useful noninvasive Cr screening platform using NIR light spectroscopy.
文摘In this work two different fluorochromes （Alexa 594 and Alexa 680） are conjugated to the same monoclonal antibody （Cetuximab） for obtaining a characteristic M-shaped dual-peak spectrum. Dual-labeling of Cetuximab by mixing both fluorochromes before the conjugation step gives spectral results similar to those of mixing of fluorochrome-labeled Cetuximab after the conjugation step （P 〉 0.05）. In conclusion, both methods may be used equivalently for producing a dual-labeled single-antibody probe. Future studies may test whether the M-shaped spectrum may increase the diagnostic confidence in tumor-targeted multispectral optical imaging.
基金supported in part by the National Science Foundation of China under Grant number 61471090the National HighTech R&D Program of China under Grant number 2014AA01A707+1 种基金the Fundamental Research Funds for the Central Universities(No.ZYGX2013J112)the Foundation Project of National Key Laboratory of Science and Technology on Communications under Grant 9140C020108140C02005
文摘High peak-to-average-power ratio(PAPR) and spectral leakage are two main drawbacks of multicarrier systems, such as in orthogonal frequency division multiplexing(OFDM), in future 5G wireless communications. For generating optimized wave forms for 5G communications, this paper proposes an iterative scheme combining time-domain N-continuous OFDM(TD-NC-OFDM) and serial peak cancellation(SPC). Based on the theory of projection onto convex sets(POCS), the effectiveness of the proposed scheme is proved, and the optimized time-frequency domain multicarrier waveforms are analyzed in terms of a balanced tradeoff between out-of-band spectral leakage and PAPR. Both theoretical analysis and simulation results show that the proposed scheme can jointly optimize both the PAPR and out-ofband radiation, with moderate computational complexity.
基金This work was supported by the National Natural Science Foundation of China （No.60871037 andNo.61004133） and the Innovation and Technology Fund of Hefei Institutes of Physical Science.
文摘High field asymmetric wave ion mobility spectrometry （FAIMS） is a powerful tool to detect and characterize gas-phase ions, while the unsolvable partial differential equation of ions moving in ion drift tube poses a big challenge to FAIMS spectral peak analysis. In this work, a universal and effective model of FAIMS spectral peak profile has been proposed by introducing ion trajectory and loss height. With this model, the influence of the structure of ion drift tube, dispersion voltages, compensation voltages, and carrier gas flow rate on the FAIMS spectral peak characteristics like peak shape, full width at half maximum and peak height is analyzed and discussed. The results show that the influence of different factors on the FAIMS spectral peak profile can be qualitatively described by the model which agrees with the experimental data.
基金supported by Iranian National Institute for Oceanography and Atmospheric Science
文摘This study evaluates the capability of the Simulating WAves Nearshore(SWAN)wave model(version 41.01)in predicting significant wave height and spectral peak energy content for swell waves in very shallow water of surf zone during depth-induced wave breaking and dissipation.The model results were compared with field measurements at five nearshore stations.The results demonstrated that some breaker index formulations were successful for significant wave height prediction in surf zones.However,an incorrect shape of the energy spectrum and overestimated near spectral peak energy content at shallow water stations were obtained using all of the embedded depth-induced wave breaking formulations in SWAN.The dependent breaker index on relative depth(Kpd)formulation,which was successful in predicting near spectral peak energy content,resulted in an average error of 30%.Finally,this formulation was modified to enhance the model performance in reproducing the spectral peak energy content.
文摘针对谱聚类在尺度参数计算时需要人为设置近邻参数及聚类结果不稳定等问题,本文将初始类中心值和尺度参数作为决策变量,重点对谱聚类算法进行自适应优化与改进。首先,将样本邻域标准差的倒数作为度量样本局部密度的参数,与密度峰值思想相结合,设计了一种基于密度峰值的初始类中心决策值选择方法(initial class center decision value algorithm based on density peak,DP_KD),解决密度调整谱聚类中聚类结果不稳定的问题。其次,利用样本间的平均距离计算相应的邻域半径,并根据样本标准差自适应地求解每个样本的尺度参数,构造样本间的相似度矩阵,实现了近邻参数的自适应设置,解决尺度参数需要人为设置的问题。然后,基于优化后的初始类中心决策值和近邻参数方法,进一步调整高斯核函数,提出一种基于邻域标准差的密度调整谱聚类算法(density adjusted spectral clustering algorithm based on neighborhood standard deviation,DSSD),通过构建特征向量空间实现了密度谱聚类。最后,将提出的算法与其他聚类算法在多个数据集上进行了对比。结果表明,与其他谱聚类算法相比,本文提出的DSSD算法不仅具有更好的聚类效果,且聚类结果更加稳定,尤其是在类内密集且类间边缘明确的DIM512数据集中,DSSD算法可以正确地进行聚类分簇;在准确率、兰德系数和F-measure上较其他算法至少提升了0.0268、0.0136和0.0247,这表明DSSD算法不仅聚类效果较好且更适合大规模数据集的聚类分析。
文摘频谱兼容波形利用多段离散寂静带宽合成大带宽,在满足带宽要求的同时有效对抗频域密集干扰。为了抑制频谱兼容波形的峰值旁瓣水平,提出一种低峰值旁瓣频谱兼容波形设计方案。所提方案综合考虑波形的自相关峰值旁瓣性能和抗干扰性能,构建加权目标函数。在波形恒模约束下,该问题为非确定多项式难(non-deterministic polynomial-hard,NP-hard)问题。为此,首先利用指数对数平滑技术逼近目标函数,进而提出基于快速傅里叶变换的共轭梯度(conjugate gradient method based on fast Fourier transformation,CGFFT)法求解该问题。此外,波形设计中需要根据性能指标要求选择合适的加权值,为此提出一种加权值自适应确定方法,最后通过数值仿真验证了所提方法的有效性。
