We introduce here the concept of Bayesian networks, in compound Poisson model, which provides a graphical modeling framework that encodes the joint probability distribution for a set of random variables within a direc...We introduce here the concept of Bayesian networks, in compound Poisson model, which provides a graphical modeling framework that encodes the joint probability distribution for a set of random variables within a directed acyclic graph. We suggest an approach proposal which offers a new mixed implicit estimator. We show that the implicit approach applied in compound Poisson model is very attractive for its ability to understand data and does not require any prior information. A comparative study between learned estimates given by implicit and by standard Bayesian approaches is established. Under some conditions and based on minimal squared error calculations, we show that the mixed implicit estimator is better than the standard Bayesian and the maximum likelihood estimators. We illustrate our approach by considering a simulation study in the context of mobile communication networks.展开更多
A novel full Eulerian fluid-elastic membrane coupling method on the fixed Cartesian coordinate mesh is proposed within the framework of the volume-of-fluid approach.The present method is based on a full Eulerian fluid...A novel full Eulerian fluid-elastic membrane coupling method on the fixed Cartesian coordinate mesh is proposed within the framework of the volume-of-fluid approach.The present method is based on a full Eulerian fluid-(bulk)structure coupling solver(Sugiyama et al.,J.Comput.Phys.,230(2011)596–627),with the bulk structure replaced by elastic membranes.In this study,a closed membrane is considered,and it is described by a volume-of-fluid or volume-fraction information generally called VOF function.A smoothed indicator(or characteristic)function is introduced as a phase indicator which results in a smoothed VOF function.This smoothed VOF function uses a smoothed delta function,and it enables a membrane singular force to be incorporated into a mixture momentum equation.In order to deal with a membrane deformation on the Eulerian mesh,a deformation tensor is introduced and updated within a compactly supported region near the interface.Both the neo-Hookean and the Skalak models are employed in the numerical simulations.A smoothed(and less dissipative)interface capturing method is employed for the advection of the VOF function and the quantities defined on the membrane.The stability restriction due to membrane stiffness is relaxed by using a quasi-implicit approach.The present method is validated by using the spherical membrane deformation problems,and is applied to a pressure-driven flow with the biconcave membrane capsules(red blood cells).展开更多
It is well-established that individual innovativeness is an indispensable quality for employees working in a variety of workplace environments.However,the interaction between the psychological and organizational facto...It is well-established that individual innovativeness is an indispensable quality for employees working in a variety of workplace environments.However,the interaction between the psychological and organizational factors influencing innovativeness remains unclear.This study seeks to address that research gap by examining a model comprising a mix of psychological factors(implicit theory and goal orientation)and organizational culture.Data were collected from 315 staff members working in 34 different departments/schools at Tampere University,Finland.The study employed a Bayesian multilevel path analysis that matched the hierarchical structure of the data to test the hypotheses.The results suggest that psychological factors reflecting goal orientation are the most important for interpreting individual innovativeness.Specifically,mastery goal orientation was shown to be a positive predictor and performance-approach goal orientation a negative predictor of innovativeness.Unexpectedly,departmental culture had neither a direct effect on innovativeness nor a moderation effect on the relationships between the psychological variables and innovativeness.Plausible explanations for these results and implications for future research are discussed.展开更多
A semi-implicit and Eulerian - Lagrangian finite difference method for three-dimensionalshallow flow has been extended to a more complete system of equations incorporating second-moment turbulence closure model and tr...A semi-implicit and Eulerian - Lagrangian finite difference method for three-dimensionalshallow flow has been extended to a more complete system of equations incorporating second-moment turbulence closure model and transport equations of salinity and temperature. The simulation for flooding and drying of mudflats has been improved. The model is applied to Xiamen waters. Based on extensive survey data, water level elevation, temperature and salinity field along the eastern open boundary and at the Jiulong River inlets and runoffs are analyzed, specified and calibrated. The computed results show good agreement with the measured data, reproduce flooding, emergence of large and complex mudflat region.展开更多
在机电暂态仿真计算中,常用的稀疏三角分解存在分解效率不高、并行度低等问题。基于隐式梯形积分法,首先根据雅克比矩阵的特点,将雅可比矩阵分裂,然后利用扩展的Sherrman-Morrison求逆公式递推求解,从而避免了稀疏三角分解,得到了一类...在机电暂态仿真计算中,常用的稀疏三角分解存在分解效率不高、并行度低等问题。基于隐式梯形积分法,首先根据雅克比矩阵的特点,将雅可比矩阵分裂,然后利用扩展的Sherrman-Morrison求逆公式递推求解,从而避免了稀疏三角分解,得到了一类新的机电暂态仿真算法。利用高性能的图形处理器(Graphics Processing Unit, GPU)对大规模合成系统进行仿真测试。结果分析表明,所提出的并行算法可以获得较好的加速比和良好的扩展性。展开更多
The implicit nonlinear normal mode initialization (INMI) is applied to a tropical limited area shallow water model in spherical coordinates.The boundary condition for the INMI scheme is based on the boundary formulati...The implicit nonlinear normal mode initialization (INMI) is applied to a tropical limited area shallow water model in spherical coordinates.The boundary condition for the INMI scheme is based on the boundary formulation of the model.The INMI scheme is found to be very efficient in suppressing spurious gravity wave oscillation and providing a well balanced initial data set for the model.The INMI scheme involves solving a number of elliptic type equations with varying complexity.and hence an efficient numerical technique is required for solving such equations.In order to make INMI computationally more attractive,we are employing the multigrid method for solving all the elliptic type equations in the INMI scheme.The numerical procedures for the development of such multigrid solvers are briefly described.展开更多
文摘We introduce here the concept of Bayesian networks, in compound Poisson model, which provides a graphical modeling framework that encodes the joint probability distribution for a set of random variables within a directed acyclic graph. We suggest an approach proposal which offers a new mixed implicit estimator. We show that the implicit approach applied in compound Poisson model is very attractive for its ability to understand data and does not require any prior information. A comparative study between learned estimates given by implicit and by standard Bayesian approaches is established. Under some conditions and based on minimal squared error calculations, we show that the mixed implicit estimator is better than the standard Bayesian and the maximum likelihood estimators. We illustrate our approach by considering a simulation study in the context of mobile communication networks.
文摘A novel full Eulerian fluid-elastic membrane coupling method on the fixed Cartesian coordinate mesh is proposed within the framework of the volume-of-fluid approach.The present method is based on a full Eulerian fluid-(bulk)structure coupling solver(Sugiyama et al.,J.Comput.Phys.,230(2011)596–627),with the bulk structure replaced by elastic membranes.In this study,a closed membrane is considered,and it is described by a volume-of-fluid or volume-fraction information generally called VOF function.A smoothed indicator(or characteristic)function is introduced as a phase indicator which results in a smoothed VOF function.This smoothed VOF function uses a smoothed delta function,and it enables a membrane singular force to be incorporated into a mixture momentum equation.In order to deal with a membrane deformation on the Eulerian mesh,a deformation tensor is introduced and updated within a compactly supported region near the interface.Both the neo-Hookean and the Skalak models are employed in the numerical simulations.A smoothed(and less dissipative)interface capturing method is employed for the advection of the VOF function and the quantities defined on the membrane.The stability restriction due to membrane stiffness is relaxed by using a quasi-implicit approach.The present method is validated by using the spherical membrane deformation problems,and is applied to a pressure-driven flow with the biconcave membrane capsules(red blood cells).
文摘It is well-established that individual innovativeness is an indispensable quality for employees working in a variety of workplace environments.However,the interaction between the psychological and organizational factors influencing innovativeness remains unclear.This study seeks to address that research gap by examining a model comprising a mix of psychological factors(implicit theory and goal orientation)and organizational culture.Data were collected from 315 staff members working in 34 different departments/schools at Tampere University,Finland.The study employed a Bayesian multilevel path analysis that matched the hierarchical structure of the data to test the hypotheses.The results suggest that psychological factors reflecting goal orientation are the most important for interpreting individual innovativeness.Specifically,mastery goal orientation was shown to be a positive predictor and performance-approach goal orientation a negative predictor of innovativeness.Unexpectedly,departmental culture had neither a direct effect on innovativeness nor a moderation effect on the relationships between the psychological variables and innovativeness.Plausible explanations for these results and implications for future research are discussed.
文摘A semi-implicit and Eulerian - Lagrangian finite difference method for three-dimensionalshallow flow has been extended to a more complete system of equations incorporating second-moment turbulence closure model and transport equations of salinity and temperature. The simulation for flooding and drying of mudflats has been improved. The model is applied to Xiamen waters. Based on extensive survey data, water level elevation, temperature and salinity field along the eastern open boundary and at the Jiulong River inlets and runoffs are analyzed, specified and calibrated. The computed results show good agreement with the measured data, reproduce flooding, emergence of large and complex mudflat region.
文摘在机电暂态仿真计算中,常用的稀疏三角分解存在分解效率不高、并行度低等问题。基于隐式梯形积分法,首先根据雅克比矩阵的特点,将雅可比矩阵分裂,然后利用扩展的Sherrman-Morrison求逆公式递推求解,从而避免了稀疏三角分解,得到了一类新的机电暂态仿真算法。利用高性能的图形处理器(Graphics Processing Unit, GPU)对大规模合成系统进行仿真测试。结果分析表明,所提出的并行算法可以获得较好的加速比和良好的扩展性。
文摘The implicit nonlinear normal mode initialization (INMI) is applied to a tropical limited area shallow water model in spherical coordinates.The boundary condition for the INMI scheme is based on the boundary formulation of the model.The INMI scheme is found to be very efficient in suppressing spurious gravity wave oscillation and providing a well balanced initial data set for the model.The INMI scheme involves solving a number of elliptic type equations with varying complexity.and hence an efficient numerical technique is required for solving such equations.In order to make INMI computationally more attractive,we are employing the multigrid method for solving all the elliptic type equations in the INMI scheme.The numerical procedures for the development of such multigrid solvers are briefly described.
