A new method is developed to simulate the skew normal distribution. The result is interesting from a practical as well as a theoretical viewpoint. The new method is simple to program and is more efficient than the sta...A new method is developed to simulate the skew normal distribution. The result is interesting from a practical as well as a theoretical viewpoint. The new method is simple to program and is more efficient than the standard method of simulation by acceptance-rejection method.展开更多
Background/Aims: Determining the levels of oral health and the quality of dental care are fundamental to building concepts of oral health. This study aims to assess toothbrushing techniques using a technical and physi...Background/Aims: Determining the levels of oral health and the quality of dental care are fundamental to building concepts of oral health. This study aims to assess toothbrushing techniques using a technical and physical model, clarifying how children and pre-adults learn to brush their teeth. Materials and Methods: Data were recorded from 23 participants, both male and female of various ages, using a proposed electronic toothbrush equipped with X-Y-Z axes pathways. The data, collected before and after training experiments, were processed with MATLAB to generate plots for the three axes. Results: The study revealed that most parameter values, such as Mean Difference Between Amplitudes (MAV, 6.00), Wilson Amplitude (WAMP, 179.419), and Average Amplitude Coupling (AAC, 1.270), decreased from before to after the experiments. Furthermore, the average overall epoch lengths (AVG) showed a 75% reduction in movement amplitude between the two experiments. Conclusion: Dentist observations indicated which brushing methods were acceptable or not. Analytical values suggest that individuals learn the toothbrushing technique effectively, and medical observations clearly demonstrate the success of the proposed method.展开更多
The dura mater is of similar embryological origin to the fascial organ. It contains several fibroblasts which make the dura mater a flexible structure. Dura mater is the outermost of the three layers of meninges, a th...The dura mater is of similar embryological origin to the fascial organ. It contains several fibroblasts which make the dura mater a flexible structure. Dura mater is the outermost of the three layers of meninges, a thick and rigid inelastic membrane that covers the brain and spinal cord and that is impermeable to the cerebrospinal fluid. The cranial dura mater in certain respects differs anatomically from the dura material in the spinal cord, and it is important to classify them separately. This article reviews the anatomical structure of spinal and cranial dura mater and its anatomy with muscle, fascia, bone structure and ligaments. Dura mater is a structure in the body that is connected with systemic functions.展开更多
Oral health problems such as periodontal diseases, dental caries, and endodontic infections have a significant negative impact on oral health and impose a substantial financial burden on the global population. The pre...Oral health problems such as periodontal diseases, dental caries, and endodontic infections have a significant negative impact on oral health and impose a substantial financial burden on the global population. The prevalence of these issues is increasing due to the buildup of bacterial plaque and the growing resistance of bacteria to antimicrobial treatments. The aims of this study to evaluate the anti-bacterial activity of four types of antibiotics (Amoxicillin, Augmentin, Azithromycin and Metronidazole) and four types of toothpastes (Sensodyne, ipana, denta and cariax Gingival Kin) on two oral pathogenic bacteria (Streptococcus mutans and Staphylococcus epidermidis). Bacterial samples of previously isolated Streptococcus mutans and Staphylococcusepidermidis were used as test organisms and the Kirby-Bauer disc diffusion method was employed to assess the antibacterial efficacy of various antibiotics and evaluate the impact of different toothpastes using a filter paper disc agar measurement technique. Each filter disc was saturated with toothpaste solution in a test tube for approximately 30 to 40 seconds, after which they were placed on Mueller-Hinton broth bacterial cultures in petri dishes. These Petri dishes were then incubated at 37°C for 24 hours, and the clear zone’s diameter (inhibition zone in mm) was subsequently measured and the results were recorded. The results demonstrated that Sensodyne toothpaste and Metronidazole antibiotic were ineffective against both types of bacteria, while Augmentin and Amoxicillin were effective by high diameter inhibition zones of growth against S. mutans and Azithromycine against S. epidermidis. Also Ipana, Denta, and Cariax Gingival Kin toothpastes exhibited a moderate effect against the two bacteria. This study suggests that certain antibiotics and toothpastes can effectively inhibit the growth of harmful oral bacteria, but not all of them are effective.展开更多
In this article,we study the convergence of an IIPG(Incomplete Interior Penalty Galerkin)Discontinuous Galerkin numerical method for the Richards equation.The Richards equation is a degenerate parabolic nonlinear equa...In this article,we study the convergence of an IIPG(Incomplete Interior Penalty Galerkin)Discontinuous Galerkin numerical method for the Richards equation.The Richards equation is a degenerate parabolic nonlinear equation for modeling flows in porous media with variable saturation.The numerical solution of this equation is known to be difficult to calculate numerically,due to the abrupt displacement of the wetting front,mainly as a result of highly nonlinear hydraulic properties.As time scales are slow,implicit numerical methods are required,and the convergence of nonlinear solvers is very sensitive.We propose an original method to ensure convergence of the numerical solution to the exact Richards solution,using a technique of auto-calibration of the penalty parameters derived from the Galerkin Discontinuous method.The method is constructed using nonlinear 1D and 2D general elliptic problems.We show that the numerical solution converges toward the unique solution of the continuous problem under certain conditions on the penalty parameters.Then,we numerically demonstrate the efficiency and robustness of the method through test cases with analytical solutions,laboratory test cases,and large-scale simulations.展开更多
We propose a new section-averaged one-dimensional model for blood flows in deformable arteries.The model is derived from the three-dimensional Navier-Stokes equations,written in cylindrical coordinates,under the“thin...We propose a new section-averaged one-dimensional model for blood flows in deformable arteries.The model is derived from the three-dimensional Navier-Stokes equations,written in cylindrical coordinates,under the“thin-artery”assumption(similar to the“shallow-water”assumption for free surface models).The blood flow/artery interaction is taken into account through suitable boundary conditions.The obtained equations enter the scope of the nonlinear convection-diffusion problems.We show that the resulting model is energetically consistent.The proposed model extends most extant models by adding more scope,depending on an additional viscous term.We compare both models computationally based on an Incomplete Interior Penalty Galerkin(IIPG)method for the parabolic part,and on a Runge Kutta Discontinuous Galerkin(RKDG)method for the hyperbolic part.The time discretization explicit/implicit is based on the well-known Additive Runge-Kutta(ARK)method.Moreover,through a suitable change of variables,by construction,we show that the numerical scheme is well-balanced,i.e.,it preserves exactly still-steady state solutions.To end,we numerically investigate its efficiency through several test cases with a confrontation to an exact solution.展开更多
We propose a new two-dimensional blood flow reduced model taking into account of complex artery geometry as in the case of severe aneurysm.We derive the model from the three-dimensional Navier-Stokes equations written...We propose a new two-dimensional blood flow reduced model taking into account of complex artery geometry as in the case of severe aneurysm.We derive the model from the three-dimensional Navier-Stokes equations written in a curvilinear coordinate system under the thin-artery assumption,with boundary conditions including wall tissue deformation.We show that the model is energetically consistent with the full Navier-Stokes problem.This model,obtained via radial averaging,is,up to our knowledge,the first one.It has the advantage of being more accurate than the classical one-dimensional models and being solved in a reasonable time in comparison with the Navier-Stokes models.To this purpose,we use a Runge-Kutta Discontinuous Galerkin(RKDG)method to solve the two-dimensional problem.We end the paper with several numerical test cases to show the efficiency and robustness of the numerical model,and in particular,we show the limit of the one-dimensional models in the case of a severe aneurysm.展开更多
We investigate a version of one velocity Baer-Nunziato model with dissipation for the mixture of two compressible fluids with the goal to prove for it the existence of weak solutions for arbitrary large initial data o...We investigate a version of one velocity Baer-Nunziato model with dissipation for the mixture of two compressible fluids with the goal to prove for it the existence of weak solutions for arbitrary large initial data on a large time interval.We transform the one velocity Baer-Nunziato system to another"more academic"system which possesses the clear"Navier-Stokes structure".We solve the new system by adapting to its structure the Lions approach for solving the(mono-fluid)compressible Navier-Stokes equations.An extension of the theory of renormalized solutions to the transport equation to more continuity equations with renormalizing functions of several variables is essential in this process.We derive a criterion of almost uniqueness for the renormalized solutions to the pure transport equation without the classical assumption on the boundedness of the divergence of the transporting velocity.This result does not follow from the DiPerna-Lions transport theory and it is of independent interest.This criterion plays the crucial role in the identification of the weak solutions to the original one velocity Baer-Nunziato problem starting from the weak solutions of the academic problem.As far as we know,this is the first result on the existence of weak solutions for a version of the one velocity bi-fluid system of the Baer-Nunziato type in the mathematical literature.展开更多
We consider the Navier-Stokes equations with a pressure function satisfying a hard-sphere law.That means the pressure,as a function of the density,becomes infinite when the density approaches a finite critical value.U...We consider the Navier-Stokes equations with a pressure function satisfying a hard-sphere law.That means the pressure,as a function of the density,becomes infinite when the density approaches a finite critical value.Under some structural constraints imposed on the pressure law,we show a weak-strong uniqueness principle in periodic spatial domains.The method is based on a modified relative entropy inequality for the system.The main difficulty is that the pressure potential associated with the internal energy of the system is largely dominated by the pressure itself in the area close to the critical density.As a result,several terms appearing in the relative energy inequality cannot be controlled by the total energy.展开更多
Our aim is to evidence new 3D composite diffractive structures whose effective permittivity tensor can exhibit very large positive or negative real eigenvalues.We use a reiterated homogenization procedure in which the...Our aim is to evidence new 3D composite diffractive structures whose effective permittivity tensor can exhibit very large positive or negative real eigenvalues.We use a reiterated homogenization procedure in which the first step consists in considering a bounded obstacle made of periodically disposed parallel high conducting metallic fibers of finite length and very thin cross section.As shown in[2],the resulting constitutive law is non-local.Then by reproducing periodically the same kind of obstacle at small scale,we obtain a local effective law described by a permittivity tensor that we make explicit as a function of the frequency.Due to internal resonances,the eigenvalues of this tensor have real part that change of sign and are possibly very large within some range of frequencies.Numerical simulations are shown.展开更多
文摘A new method is developed to simulate the skew normal distribution. The result is interesting from a practical as well as a theoretical viewpoint. The new method is simple to program and is more efficient than the standard method of simulation by acceptance-rejection method.
文摘Background/Aims: Determining the levels of oral health and the quality of dental care are fundamental to building concepts of oral health. This study aims to assess toothbrushing techniques using a technical and physical model, clarifying how children and pre-adults learn to brush their teeth. Materials and Methods: Data were recorded from 23 participants, both male and female of various ages, using a proposed electronic toothbrush equipped with X-Y-Z axes pathways. The data, collected before and after training experiments, were processed with MATLAB to generate plots for the three axes. Results: The study revealed that most parameter values, such as Mean Difference Between Amplitudes (MAV, 6.00), Wilson Amplitude (WAMP, 179.419), and Average Amplitude Coupling (AAC, 1.270), decreased from before to after the experiments. Furthermore, the average overall epoch lengths (AVG) showed a 75% reduction in movement amplitude between the two experiments. Conclusion: Dentist observations indicated which brushing methods were acceptable or not. Analytical values suggest that individuals learn the toothbrushing technique effectively, and medical observations clearly demonstrate the success of the proposed method.
文摘The dura mater is of similar embryological origin to the fascial organ. It contains several fibroblasts which make the dura mater a flexible structure. Dura mater is the outermost of the three layers of meninges, a thick and rigid inelastic membrane that covers the brain and spinal cord and that is impermeable to the cerebrospinal fluid. The cranial dura mater in certain respects differs anatomically from the dura material in the spinal cord, and it is important to classify them separately. This article reviews the anatomical structure of spinal and cranial dura mater and its anatomy with muscle, fascia, bone structure and ligaments. Dura mater is a structure in the body that is connected with systemic functions.
文摘Oral health problems such as periodontal diseases, dental caries, and endodontic infections have a significant negative impact on oral health and impose a substantial financial burden on the global population. The prevalence of these issues is increasing due to the buildup of bacterial plaque and the growing resistance of bacteria to antimicrobial treatments. The aims of this study to evaluate the anti-bacterial activity of four types of antibiotics (Amoxicillin, Augmentin, Azithromycin and Metronidazole) and four types of toothpastes (Sensodyne, ipana, denta and cariax Gingival Kin) on two oral pathogenic bacteria (Streptococcus mutans and Staphylococcus epidermidis). Bacterial samples of previously isolated Streptococcus mutans and Staphylococcusepidermidis were used as test organisms and the Kirby-Bauer disc diffusion method was employed to assess the antibacterial efficacy of various antibiotics and evaluate the impact of different toothpastes using a filter paper disc agar measurement technique. Each filter disc was saturated with toothpaste solution in a test tube for approximately 30 to 40 seconds, after which they were placed on Mueller-Hinton broth bacterial cultures in petri dishes. These Petri dishes were then incubated at 37°C for 24 hours, and the clear zone’s diameter (inhibition zone in mm) was subsequently measured and the results were recorded. The results demonstrated that Sensodyne toothpaste and Metronidazole antibiotic were ineffective against both types of bacteria, while Augmentin and Amoxicillin were effective by high diameter inhibition zones of growth against S. mutans and Azithromycine against S. epidermidis. Also Ipana, Denta, and Cariax Gingival Kin toothpastes exhibited a moderate effect against the two bacteria. This study suggests that certain antibiotics and toothpastes can effectively inhibit the growth of harmful oral bacteria, but not all of them are effective.
基金supported by the ADEN-MED project(Adaptability to Extreme events and Natural risks-application to the Mediterranean and Djibouti),funded by the Region Sud Provence-Alpes-Cote d’Azur under the AAP MEDCLIMAT“Natural risks and food sovereignty”by France 2030 through the Priority Research Program and Equipment(PEPR)“Maths-Vives-Mathematics in Interactions”,targeted project HYDRAUMATH(ANR-23-EXMA-007),operated by ANR.
文摘In this article,we study the convergence of an IIPG(Incomplete Interior Penalty Galerkin)Discontinuous Galerkin numerical method for the Richards equation.The Richards equation is a degenerate parabolic nonlinear equation for modeling flows in porous media with variable saturation.The numerical solution of this equation is known to be difficult to calculate numerically,due to the abrupt displacement of the wetting front,mainly as a result of highly nonlinear hydraulic properties.As time scales are slow,implicit numerical methods are required,and the convergence of nonlinear solvers is very sensitive.We propose an original method to ensure convergence of the numerical solution to the exact Richards solution,using a technique of auto-calibration of the penalty parameters derived from the Galerkin Discontinuous method.The method is constructed using nonlinear 1D and 2D general elliptic problems.We show that the numerical solution converges toward the unique solution of the continuous problem under certain conditions on the penalty parameters.Then,we numerically demonstrate the efficiency and robustness of the method through test cases with analytical solutions,laboratory test cases,and large-scale simulations.
基金supported by the ADEN-MED project(Adaptability to Extreme Events and Natural Risks-Application to the Mediterranean and Djibouti)funded by the Région Sud Provence-Alpes-Côte d’Azur under the AAP MEDCLIMAT“Natural Risks and Food Sovereignty”.
文摘We propose a new section-averaged one-dimensional model for blood flows in deformable arteries.The model is derived from the three-dimensional Navier-Stokes equations,written in cylindrical coordinates,under the“thin-artery”assumption(similar to the“shallow-water”assumption for free surface models).The blood flow/artery interaction is taken into account through suitable boundary conditions.The obtained equations enter the scope of the nonlinear convection-diffusion problems.We show that the resulting model is energetically consistent.The proposed model extends most extant models by adding more scope,depending on an additional viscous term.We compare both models computationally based on an Incomplete Interior Penalty Galerkin(IIPG)method for the parabolic part,and on a Runge Kutta Discontinuous Galerkin(RKDG)method for the hyperbolic part.The time discretization explicit/implicit is based on the well-known Additive Runge-Kutta(ARK)method.Moreover,through a suitable change of variables,by construction,we show that the numerical scheme is well-balanced,i.e.,it preserves exactly still-steady state solutions.To end,we numerically investigate its efficiency through several test cases with a confrontation to an exact solution.
文摘We propose a new two-dimensional blood flow reduced model taking into account of complex artery geometry as in the case of severe aneurysm.We derive the model from the three-dimensional Navier-Stokes equations written in a curvilinear coordinate system under the thin-artery assumption,with boundary conditions including wall tissue deformation.We show that the model is energetically consistent with the full Navier-Stokes problem.This model,obtained via radial averaging,is,up to our knowledge,the first one.It has the advantage of being more accurate than the classical one-dimensional models and being solved in a reasonable time in comparison with the Navier-Stokes models.To this purpose,we use a Runge-Kutta Discontinuous Galerkin(RKDG)method to solve the two-dimensional problem.We end the paper with several numerical test cases to show the efficiency and robustness of the numerical model,and in particular,we show the limit of the one-dimensional models in the case of a severe aneurysm.
文摘We investigate a version of one velocity Baer-Nunziato model with dissipation for the mixture of two compressible fluids with the goal to prove for it the existence of weak solutions for arbitrary large initial data on a large time interval.We transform the one velocity Baer-Nunziato system to another"more academic"system which possesses the clear"Navier-Stokes structure".We solve the new system by adapting to its structure the Lions approach for solving the(mono-fluid)compressible Navier-Stokes equations.An extension of the theory of renormalized solutions to the transport equation to more continuity equations with renormalizing functions of several variables is essential in this process.We derive a criterion of almost uniqueness for the renormalized solutions to the pure transport equation without the classical assumption on the boundedness of the divergence of the transporting velocity.This result does not follow from the DiPerna-Lions transport theory and it is of independent interest.This criterion plays the crucial role in the identification of the weak solutions to the original one velocity Baer-Nunziato problem starting from the weak solutions of the academic problem.As far as we know,this is the first result on the existence of weak solutions for a version of the one velocity bi-fluid system of the Baer-Nunziato type in the mathematical literature.
基金the European Research Council under the European Union’s Seventh Framework Programme (Grant No. FP7/2007-2013)European Research Council (ERC) Grant Agreement (Grant No. 320078)The Institute of Mathematics of the Academy of Sciences of the Czech Republic was supported by Rozvoj Vyzkumn Organizace (RVO) (Grant No. 67985840)
文摘We consider the Navier-Stokes equations with a pressure function satisfying a hard-sphere law.That means the pressure,as a function of the density,becomes infinite when the density approaches a finite critical value.Under some structural constraints imposed on the pressure law,we show a weak-strong uniqueness principle in periodic spatial domains.The method is based on a modified relative entropy inequality for the system.The main difficulty is that the pressure potential associated with the internal energy of the system is largely dominated by the pressure itself in the area close to the critical density.As a result,several terms appearing in the relative energy inequality cannot be controlled by the total energy.
基金support of ANR projects POEM(PNANO 06-0030)OPTRANS(2010 BLAN 012403).
文摘Our aim is to evidence new 3D composite diffractive structures whose effective permittivity tensor can exhibit very large positive or negative real eigenvalues.We use a reiterated homogenization procedure in which the first step consists in considering a bounded obstacle made of periodically disposed parallel high conducting metallic fibers of finite length and very thin cross section.As shown in[2],the resulting constitutive law is non-local.Then by reproducing periodically the same kind of obstacle at small scale,we obtain a local effective law described by a permittivity tensor that we make explicit as a function of the frequency.Due to internal resonances,the eigenvalues of this tensor have real part that change of sign and are possibly very large within some range of frequencies.Numerical simulations are shown.
