Diffuse interfaces appear with any Eulerian discontinuity capturing compressible flow solver. When dealing with multifluid and multimaterial computations, interfaces smearing results in serious difficulties to fulfil ...Diffuse interfaces appear with any Eulerian discontinuity capturing compressible flow solver. When dealing with multifluid and multimaterial computations, interfaces smearing results in serious difficulties to fulfil contact conditions, as spurious oscillations appear. To circumvent these difficulties, several approaches have been proposed. One of them relies on multiphase flow modelling of the numerically diffused zone and is based on extended hyperbolic systems with stiff mechanical relaxation (Saurel and Abgrall, 1999 [4], Saurel et al., 2009 [6]). This approach is very robust, accurate and flexible in the sense that many physical effects can be included: surface tension, phase transition, elastic-plastic materials, detonations, granular effects etc. It is also able to deal with dynamic appearance of interfaces. However it suffers from an important drawback when long time evolution is under interest as the interface becomes more and more diffused. The present paper addresses this issue and provides an efficient way to sharpen interfaces. A sharpening flow model is used to correct the solution after each time step. The sharpening process is based on a hyperbolic equation that produces a steady shock in finite time at the interface location. This equation is embedded in a “sharpening multiphase model” redistributing volume fractions, masses, momentum and energy in a consistent way. The method is conservative with respect to the masses, mixture momentum and mixture energy. It results in diffused interfaces sharpened in one or two mesh points. The method is validated on test problems having exact solutions.展开更多
The Human-Centered Internet of Things(HC-IoT)is fast becoming a hotbed of security and privacy concerns.Two users can establish a common session key through a trusted server over an open communication channel using a ...The Human-Centered Internet of Things(HC-IoT)is fast becoming a hotbed of security and privacy concerns.Two users can establish a common session key through a trusted server over an open communication channel using a three-party authenticated key agreement.Most of the early authenticated key agreement systems relied on pairing,hashing,or modular exponentiation processes that are computationally intensive and cost-prohibitive.In order to address this problem,this paper offers a new three-party authenticated key agreement technique based on fractional chaotic maps.The new scheme uses fractional chaotic maps and supports the dynamic sensing of HC-IoT devices in the network architecture without a password table.The projected security scheme utilized a hash function,which works well for the resource-limited HC-IoT architectures.Test results show that our new technique is resistant to password guessing attacks since it does not use a password.Furthermore,our approach provides users with comprehensive privacy protection,ensuring that a user forgery attack causes no harm.Finally,our new technique offers better security features than the techniques currently available in the literature.展开更多
Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution.The limiting distribut...Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution.The limiting distributions of the test statistics are derived under the null hypothesis and under any fixed alternative.The asymptotic properties of bootstrap approximation are investigated.Furthermore,for computational reasons,an approximation for the statistics,based on the number theoretic method,is suggested.展开更多
The compressed sensing matrices based on affine symplectic space are constructed. Meanwhile, a comparison is made with the compressed sensing matrices constructed by DeVore based on polynomials over finite fields. Mor...The compressed sensing matrices based on affine symplectic space are constructed. Meanwhile, a comparison is made with the compressed sensing matrices constructed by DeVore based on polynomials over finite fields. Moreover, we merge our binary matrices with other low coherence matrices such as Hadamard matrices and discrete fourier transform(DFT) matrices using the embedding operation. In the numerical simulations, our matrices and modified matrices are superior to Gaussian matrices and DeVore’s matrices in the performance of recovering original signals.展开更多
A new era for cancer treatment has been ushered in with the field of cancer immunotherapy. After initial success with systemic malignancies, several of these promising treatments are being investigated for efficacy wi...A new era for cancer treatment has been ushered in with the field of cancer immunotherapy. After initial success with systemic malignancies, several of these promising treatments are being investigated for efficacy with primary and secondary brain tumors. Chimeric antigen receptor (CAR) T cells are being studied, both with systemic infusion and direct administration to the tumor and into the cerebrospinal fluid, with promising early results. Systemic CAR-T treatment can have serious systemic and neurological toxicities that are important for the practicing neurologist and neuro-oncologist to know and understand. This review aims to discuss adoptive cell therapies with a focus on CAR-T treatment. We review use of this therapy in brain cancers, particularly malignant glioma, and provide an overview of the toxicity of CAR-T treatment and its appropriate management.展开更多
Cancer spread is a dynamical process occurring not only in time but also in space which,for solid tumors at least,can be modeled quantitatively by reaction and diffusion equations with a bistable behavior:tumor cell c...Cancer spread is a dynamical process occurring not only in time but also in space which,for solid tumors at least,can be modeled quantitatively by reaction and diffusion equations with a bistable behavior:tumor cell colonization happens in a portion of tissue and propagates,but in some cases the process is stopped.Such a cancer proliferation/extintion dynamics is obtained in many mathematical models as a limit of complicated interacting biological fields.In this article we present a very basic model of cancer proliferation adopting the bistable equation for a single tumor cell dynamics.The reaction-diffusion theory is numerically and analytically studied and then extended in order to take into account dispersal effects in cancer progression in analogy with ecological models based on the porous medium equation.Possible implications of this approach for explanation and prediction of tumor development on the lines of existing studies on brain cancer progression are discussed.The potential role of continuum models in connecting the two predominant interpretative theories about cancer,once formalized in appropriatemathematical terms,is discussed。展开更多
Spiral waves appear in many different natural contexts:excitable biological tissues,fungi and amoebae colonies,chemical reactions,growing crystals,fluids and gas eddies as well as in galaxies.While the existing theori...Spiral waves appear in many different natural contexts:excitable biological tissues,fungi and amoebae colonies,chemical reactions,growing crystals,fluids and gas eddies as well as in galaxies.While the existing theories explain the presence of spirals in terms of nonlinear parabolic equations,it is explored here the fact that selfsustained spiral wave regime is already present in the linear heat operator,in terms of integer Bessel functions of complex argument.Such solutions,even if commonly not discussed in the literature because diverging at spatial infinity,play a central role in the understanding of the universality of spiral process.In particular,we have studied how in nonlinear reaction-diffusion models the linear part of the equations determines the wave front appearance while nonlinearities are mandatory to cancel out the blowup of solutions.The spiral wave pattern still requires however at least two cross-reacting species to be physically realized.Biological implications of such a results are discussed.展开更多
Background： Gene co-expression and differential co-expression analysis has been increasingly used to study co- functional and co-regulatory biological mechanisms from large scale transcriptomics data sets. Methods： ...Background： Gene co-expression and differential co-expression analysis has been increasingly used to study co- functional and co-regulatory biological mechanisms from large scale transcriptomics data sets. Methods： In this study, we develop a nonparametric approach to identify hub genes and modules in a large co- expression network with low computational and memory cost, namely MRHCA. Results： We have applied the method to simulated transcriptomics data sets and demonstrated MRHCA can accurately identify hub genes and estimate size of co-expression modules. With applying MRHCA and differential co- expression analysis to E. coil and TCGA cancer data, we have identified significant condition specific activated genes in E. coil and distinct gene expression regulatory mechanisms between the cancer types with high copy number variation and small somatic mutations. Conclusion： Our analysis has demonstrated MRItCA can （i） deal with large association networks, （ii） rigorously assess statistical significance for hubs and module sizes, （iii） identify co-expression modules with low associations, （iv） detect small and significant modules, and （v） allow genes to be present in more than one modules, compared with existing methods.展开更多
文摘Diffuse interfaces appear with any Eulerian discontinuity capturing compressible flow solver. When dealing with multifluid and multimaterial computations, interfaces smearing results in serious difficulties to fulfil contact conditions, as spurious oscillations appear. To circumvent these difficulties, several approaches have been proposed. One of them relies on multiphase flow modelling of the numerically diffused zone and is based on extended hyperbolic systems with stiff mechanical relaxation (Saurel and Abgrall, 1999 [4], Saurel et al., 2009 [6]). This approach is very robust, accurate and flexible in the sense that many physical effects can be included: surface tension, phase transition, elastic-plastic materials, detonations, granular effects etc. It is also able to deal with dynamic appearance of interfaces. However it suffers from an important drawback when long time evolution is under interest as the interface becomes more and more diffused. The present paper addresses this issue and provides an efficient way to sharpen interfaces. A sharpening flow model is used to correct the solution after each time step. The sharpening process is based on a hyperbolic equation that produces a steady shock in finite time at the interface location. This equation is embedded in a “sharpening multiphase model” redistributing volume fractions, masses, momentum and energy in a consistent way. The method is conservative with respect to the masses, mixture momentum and mixture energy. It results in diffused interfaces sharpened in one or two mesh points. The method is validated on test problems having exact solutions.
基金The authors extend their gratitude to the Deanship of Scientific Research at King Khalid University for funding this work through the research group program under grant number R.G.P.1/72/42The work of Agbotiname Lucky Imoize is supported by the Nigerian Petroleum Technology Development Fund(PTDF)and the German Academic Exchange Service(DAAD)through the Nigerian-German Postgraduate Program under grant 57473408.
文摘The Human-Centered Internet of Things(HC-IoT)is fast becoming a hotbed of security and privacy concerns.Two users can establish a common session key through a trusted server over an open communication channel using a three-party authenticated key agreement.Most of the early authenticated key agreement systems relied on pairing,hashing,or modular exponentiation processes that are computationally intensive and cost-prohibitive.In order to address this problem,this paper offers a new three-party authenticated key agreement technique based on fractional chaotic maps.The new scheme uses fractional chaotic maps and supports the dynamic sensing of HC-IoT devices in the network architecture without a password table.The projected security scheme utilized a hash function,which works well for the resource-limited HC-IoT architectures.Test results show that our new technique is resistant to password guessing attacks since it does not use a password.Furthermore,our approach provides users with comprehensive privacy protection,ensuring that a user forgery attack causes no harm.Finally,our new technique offers better security features than the techniques currently available in the literature.
文摘Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution.The limiting distributions of the test statistics are derived under the null hypothesis and under any fixed alternative.The asymptotic properties of bootstrap approximation are investigated.Furthermore,for computational reasons,an approximation for the statistics,based on the number theoretic method,is suggested.
基金supported by the National Basic Research Program of China(2013CB834204)the National Natural Science Foundation of China(61571243)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe Ph.D.Candidate Research Innovation Fund of Nankai University(91822144)
文摘The compressed sensing matrices based on affine symplectic space are constructed. Meanwhile, a comparison is made with the compressed sensing matrices constructed by DeVore based on polynomials over finite fields. Moreover, we merge our binary matrices with other low coherence matrices such as Hadamard matrices and discrete fourier transform(DFT) matrices using the embedding operation. In the numerical simulations, our matrices and modified matrices are superior to Gaussian matrices and DeVore’s matrices in the performance of recovering original signals.
文摘A new era for cancer treatment has been ushered in with the field of cancer immunotherapy. After initial success with systemic malignancies, several of these promising treatments are being investigated for efficacy with primary and secondary brain tumors. Chimeric antigen receptor (CAR) T cells are being studied, both with systemic infusion and direct administration to the tumor and into the cerebrospinal fluid, with promising early results. Systemic CAR-T treatment can have serious systemic and neurological toxicities that are important for the practicing neurologist and neuro-oncologist to know and understand. This review aims to discuss adoptive cell therapies with a focus on CAR-T treatment. We review use of this therapy in brain cancers, particularly malignant glioma, and provide an overview of the toxicity of CAR-T treatment and its appropriate management.
文摘Cancer spread is a dynamical process occurring not only in time but also in space which,for solid tumors at least,can be modeled quantitatively by reaction and diffusion equations with a bistable behavior:tumor cell colonization happens in a portion of tissue and propagates,but in some cases the process is stopped.Such a cancer proliferation/extintion dynamics is obtained in many mathematical models as a limit of complicated interacting biological fields.In this article we present a very basic model of cancer proliferation adopting the bistable equation for a single tumor cell dynamics.The reaction-diffusion theory is numerically and analytically studied and then extended in order to take into account dispersal effects in cancer progression in analogy with ecological models based on the porous medium equation.Possible implications of this approach for explanation and prediction of tumor development on the lines of existing studies on brain cancer progression are discussed.The potential role of continuum models in connecting the two predominant interpretative theories about cancer,once formalized in appropriatemathematical terms,is discussed。
文摘Spiral waves appear in many different natural contexts:excitable biological tissues,fungi and amoebae colonies,chemical reactions,growing crystals,fluids and gas eddies as well as in galaxies.While the existing theories explain the presence of spirals in terms of nonlinear parabolic equations,it is explored here the fact that selfsustained spiral wave regime is already present in the linear heat operator,in terms of integer Bessel functions of complex argument.Such solutions,even if commonly not discussed in the literature because diverging at spatial infinity,play a central role in the understanding of the universality of spiral process.In particular,we have studied how in nonlinear reaction-diffusion models the linear part of the equations determines the wave front appearance while nonlinearities are mandatory to cancel out the blowup of solutions.The spiral wave pattern still requires however at least two cross-reacting species to be physically realized.Biological implications of such a results are discussed.
文摘Background： Gene co-expression and differential co-expression analysis has been increasingly used to study co- functional and co-regulatory biological mechanisms from large scale transcriptomics data sets. Methods： In this study, we develop a nonparametric approach to identify hub genes and modules in a large co- expression network with low computational and memory cost, namely MRHCA. Results： We have applied the method to simulated transcriptomics data sets and demonstrated MRHCA can accurately identify hub genes and estimate size of co-expression modules. With applying MRHCA and differential co- expression analysis to E. coil and TCGA cancer data, we have identified significant condition specific activated genes in E. coil and distinct gene expression regulatory mechanisms between the cancer types with high copy number variation and small somatic mutations. Conclusion： Our analysis has demonstrated MRItCA can （i） deal with large association networks, （ii） rigorously assess statistical significance for hubs and module sizes, （iii） identify co-expression modules with low associations, （iv） detect small and significant modules, and （v） allow genes to be present in more than one modules, compared with existing methods.
