Duality analysis of time series and complex networks has been a frontier topic during the last several decades.According to some recent approaches in this direction,the intrinsic dynamics of typical nonlinear systems ...Duality analysis of time series and complex networks has been a frontier topic during the last several decades.According to some recent approaches in this direction,the intrinsic dynamics of typical nonlinear systems can be better characterized by considering the related nonlinear time series from the perspective of networks science.In this paper,the associated network family of the unified piecewise-linear(PWL)chaotic family,which can bridge the gap of the PWL chaotic Lorenz system and the PWL chaotic Chen system,was firstly constructed and analyzed.We constructed the associated network family via the original and the modified frequency-degree mapping strategy,as well as the classical visibility graph and horizontal visibility graph strategy,after removing the transient states.Typical related network characteristics,including the network fractal dimension,of the associated network family,are computed with changes of single key parameter a.These characteristic vectors of the network are also compared with the largest Lyapunov exponent(LLE)vector of the related original dynamical system.It can be found that,some network characteristics are highly correlated with LLE vector of the original nonlinear system,i.e.,there is an internal consistency between the largest Lyapunov exponents,some typical associated network characteristics,and the related network fractal dimension index.Numerical results show that the modified frequency-degree mapping strategy can demonstrate highest correlation,which means it can behave better to capture the intrinsic characteristics of the unified PWL chaotic family.展开更多
Objective： To investigate the value of MR perfusion imaging in evaluating the curative effect of intervention treatment of hepatic cancer. Methods： 36 patients underwent MR perfusion imaging after intervention treat...Objective： To investigate the value of MR perfusion imaging in evaluating the curative effect of intervention treatment of hepatic cancer. Methods： 36 patients underwent MR perfusion imaging after intervention treatment. The quantization results were differed between carcinoma residue and benign tissue. And the diagnosis accuracy was judged, Results： There was a significant difference in mean MSI between residue tumor after surgery and the benign enhancement area. The timeintension curve of residue tumor was observed to ascend rapidly to reach the peak, whereas that of the enhancement tissue ascended slowly to reach the peak. The sensitivity and specificity of PWl on detection of residuary or recurrent tumor were 0.89 and 0.73 respectively. Conclusion： PWl is a very sensitive imaging technique that can be used to distinguish liver tissue condition after surgery. PWI contributed to early stage diagnosis and dynamic monitoring following HCC surgery.展开更多
In this paper we present a new version of Chen＇s system： a piecewise linear （PWL） Chert system of fractional-order. Via a sigmoid-like function, the discontinuous system is transformed into a continuous system. By...In this paper we present a new version of Chen＇s system： a piecewise linear （PWL） Chert system of fractional-order. Via a sigmoid-like function, the discontinuous system is transformed into a continuous system. By numerical simulations, we reveal chaotic behaviors and also multistability, i.e., the existence of small pararheter windows where, for some fixed bifurcation parameter and depending on initial conditions, coexistence of stable attractors and chaotic attractors is possible. Moreover, we show that by using an algorithm to switch the bifurcation parameter, the stable attractors can be numerically approximated.展开更多
Memristor is a newly found fourth circuit element for the next generation emerging nonvolatile memory technology. In this paper, design of new type of nonvolatile static random access memory cell is proposed by using ...Memristor is a newly found fourth circuit element for the next generation emerging nonvolatile memory technology. In this paper, design of new type of nonvolatile static random access memory cell is proposed by using a combination of memristor and complemented metal oxide semiconductor. Biolek memristor model and CMOS 180 nm technology are used to form a single cell. By introducing distinct binary logic to avoid safety margin is left for each binary logic output and enables better read/write data integrity. The total power consumption reduces from 0.407 mw (milli-watt) to 0.127 mw which is less than existing memristor based memory cell of the same CMOS technology. Read and write time is also significantly reduced. However, write time is higher than conventional 6T SRAM cell and can be reduced by increasing motion of electron in the memristor. The change of the memristor state is shown by applying piecewise linear input voltage.展开更多
Objective： To explore the application of MR perfusion-weighted imaging （PWI） in the benign and malignant prostate diseases, and evaluate the correlations of PWl features with vascular endothelial growth factor （V...Objective： To explore the application of MR perfusion-weighted imaging （PWI） in the benign and malignant prostate diseases, and evaluate the correlations of PWl features with vascular endothelial growth factor （VEGF） and microvessel density （MVD）. Methods： Seventy-four consecutive patients who were diagnosed clinically for the prostate diseases, including forty-four cases with benign prostate hyperplasia and thirty cases with prostatic cancer proved pathologically, were examined by PWI. MVD and VEGF were stained with immunohistochemical methods. Some parameters of PWl, including the steepest slope of signal intensity-time curve （SSmax） and the change in relaxation rate （ΔR2^＊ peak） at lesions, were analyzed. Correlation analysis was used to determine the relationship between the results of PWl and immunohistochemistry. Results： （1） In the benign prostate hyperplasia （BPH）, SSmax and ΔR2^＊ peak of perfusion curve were 34.2 ± 2.9 and 1.49 ± 0.11, respectively; however, in the prostatic cancer （Pca）, they were 58.6± 4.8 and 3.18 ±0.49 respectively; there were statistical differences （t = 2.16 and 2.31, P 〈 0.05）. （2） The VEGF and MVD expressions of thirty Pca patients were significantly higher than those of forty-four BPH patients （x2 = 28.64, P 〈 0.01; t = 21.2, P 〈 0.01）. MVD expressions of Pca and BPH groups showed positive associations with VEGF expressions （P 〈 0.01）. On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak showed associations with MVD and VEGF expressions （P 〈 0.01）. Conclusion： On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak can reflect MVD and VEGF expression levels in the benign and malignant prostate diseases and might be implied the tumor angiogenesis so as to distinguish benign from malignant and provide the important information for the surgeon to diagnose and treat the prostatic diseases.展开更多
文摘Duality analysis of time series and complex networks has been a frontier topic during the last several decades.According to some recent approaches in this direction,the intrinsic dynamics of typical nonlinear systems can be better characterized by considering the related nonlinear time series from the perspective of networks science.In this paper,the associated network family of the unified piecewise-linear(PWL)chaotic family,which can bridge the gap of the PWL chaotic Lorenz system and the PWL chaotic Chen system,was firstly constructed and analyzed.We constructed the associated network family via the original and the modified frequency-degree mapping strategy,as well as the classical visibility graph and horizontal visibility graph strategy,after removing the transient states.Typical related network characteristics,including the network fractal dimension,of the associated network family,are computed with changes of single key parameter a.These characteristic vectors of the network are also compared with the largest Lyapunov exponent(LLE)vector of the related original dynamical system.It can be found that,some network characteristics are highly correlated with LLE vector of the original nonlinear system,i.e.,there is an internal consistency between the largest Lyapunov exponents,some typical associated network characteristics,and the related network fractal dimension index.Numerical results show that the modified frequency-degree mapping strategy can demonstrate highest correlation,which means it can behave better to capture the intrinsic characteristics of the unified PWL chaotic family.
文摘Objective： To investigate the value of MR perfusion imaging in evaluating the curative effect of intervention treatment of hepatic cancer. Methods： 36 patients underwent MR perfusion imaging after intervention treatment. The quantization results were differed between carcinoma residue and benign tissue. And the diagnosis accuracy was judged, Results： There was a significant difference in mean MSI between residue tumor after surgery and the benign enhancement area. The timeintension curve of residue tumor was observed to ascend rapidly to reach the peak, whereas that of the enhancement tissue ascended slowly to reach the peak. The sensitivity and specificity of PWl on detection of residuary or recurrent tumor were 0.89 and 0.73 respectively. Conclusion： PWl is a very sensitive imaging technique that can be used to distinguish liver tissue condition after surgery. PWI contributed to early stage diagnosis and dynamic monitoring following HCC surgery.
基金funded by the European Regional Development Funding via RISC projectby CPER Region Haute Normandie France,the Australian Research Council via a Future Fellowship(FT110100896)Discovery Project(DP140100203)
文摘In this paper we present a new version of Chen＇s system： a piecewise linear （PWL） Chert system of fractional-order. Via a sigmoid-like function, the discontinuous system is transformed into a continuous system. By numerical simulations, we reveal chaotic behaviors and also multistability, i.e., the existence of small pararheter windows where, for some fixed bifurcation parameter and depending on initial conditions, coexistence of stable attractors and chaotic attractors is possible. Moreover, we show that by using an algorithm to switch the bifurcation parameter, the stable attractors can be numerically approximated.
文摘Memristor is a newly found fourth circuit element for the next generation emerging nonvolatile memory technology. In this paper, design of new type of nonvolatile static random access memory cell is proposed by using a combination of memristor and complemented metal oxide semiconductor. Biolek memristor model and CMOS 180 nm technology are used to form a single cell. By introducing distinct binary logic to avoid safety margin is left for each binary logic output and enables better read/write data integrity. The total power consumption reduces from 0.407 mw (milli-watt) to 0.127 mw which is less than existing memristor based memory cell of the same CMOS technology. Read and write time is also significantly reduced. However, write time is higher than conventional 6T SRAM cell and can be reduced by increasing motion of electron in the memristor. The change of the memristor state is shown by applying piecewise linear input voltage.
文摘Objective： To explore the application of MR perfusion-weighted imaging （PWI） in the benign and malignant prostate diseases, and evaluate the correlations of PWl features with vascular endothelial growth factor （VEGF） and microvessel density （MVD）. Methods： Seventy-four consecutive patients who were diagnosed clinically for the prostate diseases, including forty-four cases with benign prostate hyperplasia and thirty cases with prostatic cancer proved pathologically, were examined by PWI. MVD and VEGF were stained with immunohistochemical methods. Some parameters of PWl, including the steepest slope of signal intensity-time curve （SSmax） and the change in relaxation rate （ΔR2^＊ peak） at lesions, were analyzed. Correlation analysis was used to determine the relationship between the results of PWl and immunohistochemistry. Results： （1） In the benign prostate hyperplasia （BPH）, SSmax and ΔR2^＊ peak of perfusion curve were 34.2 ± 2.9 and 1.49 ± 0.11, respectively; however, in the prostatic cancer （Pca）, they were 58.6± 4.8 and 3.18 ±0.49 respectively; there were statistical differences （t = 2.16 and 2.31, P 〈 0.05）. （2） The VEGF and MVD expressions of thirty Pca patients were significantly higher than those of forty-four BPH patients （x2 = 28.64, P 〈 0.01; t = 21.2, P 〈 0.01）. MVD expressions of Pca and BPH groups showed positive associations with VEGF expressions （P 〈 0.01）. On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak showed associations with MVD and VEGF expressions （P 〈 0.01）. Conclusion： On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak can reflect MVD and VEGF expression levels in the benign and malignant prostate diseases and might be implied the tumor angiogenesis so as to distinguish benign from malignant and provide the important information for the surgeon to diagnose and treat the prostatic diseases.
