Most existing work on survivability in mobile ad-hoc networks(MANETs) focuses on two dimensional(2D) networks.However,many real applications run in three dimensional(3D) networks,e.g.,climate and ocean monitoring,and ...Most existing work on survivability in mobile ad-hoc networks(MANETs) focuses on two dimensional(2D) networks.However,many real applications run in three dimensional(3D) networks,e.g.,climate and ocean monitoring,and air defense systems.The impact on network survivability due to node behaviors was presented,and a quantitative analysis method on survivability was developed in 3D MANETs by modeling node behaviors and analyzing 3D network connectivity.Node behaviors were modeled by using a semi-Markov process.The node minimum degree of 3D MANETs was discussed.An effective approach to derive the survivability of k-connected networks was proposed through analyzing the connectivity of 3D MANETs caused by node misbehaviors,based on the model of node isolation.The quantitative analysis of node misbehaviors on the survivability in 3D MANETs is obtained through mathematical description,and the effectiveness and rationality of the proposed approach are verified through numerical analysis.The analytical results show that the effect from black and gray attack on network survivability is much severer than other misbehaviors.展开更多
Equivalent integrated finite element method is a canonical and efficient modeling method in dynamic analysis of complex mechanism. The key of establishing dynamic equations of spatial mechanism by the method is to con...Equivalent integrated finite element method is a canonical and efficient modeling method in dynamic analysis of complex mechanism. The key of establishing dynamic equations of spatial mechanism by the method is to confirm Jacobian matrix reflecting relations of all joints,nodes,and generalized coordinates,namely,relations of second-order and corresponding third-order conversion tensors. For complex motion relations of components in a parallel robot,it gives second-order and third-order conversion tensors of dynamic equations for the 6-HTRT parallel robot based on equivalent integrated finite element method. The method is suitable for the typical robots whose positions of work space and sizes of mechanism are different. The solving course of the method is simple and convenient,so the method lays the foundation of dynamic analysis for robots.展开更多
From the simulation software selection, meteorological data collection, model, boundary conditions, calculation setting and evaluation indicators, the paper summarize simulation method of wind, light and sound, summar...From the simulation software selection, meteorological data collection, model, boundary conditions, calculation setting and evaluation indicators, the paper summarize simulation method of wind, light and sound, summarize three kinds of environmental. The paper study on optimization analysis method of green building from four aspects of building orientation, architectural form, architectural layout and indoor environment, and puts forward the optimization scheme of the typical simulation analysis of simple questions; provide guidance for optimizing the design of green building. Finally, ECOTECT can adapt to the current domestic engineering design and consulting on green building simulation and design requirements, and has a broad application prospect.展开更多
A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on ...A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on non-uniform rational B-spline (NURBS) technology provides the means to build a refined three-dimensional finite element model with more accurate meshing under complex terrain and geological conditions. Meanwhile, this method is a back-analysis of ground stress with combination of multivariable linear regression model and neural network (ANN) model. Firstly, the regression model is used to fit approximately boundary loads. Regarding the regressed loads as mean value, some sets of boundary loads with the same interval are constructed according to the principle of orthogonal design, to calculate the corresponding ground stress at the observation positions using finite element method. The results (boundary loads and the corresponding ground stress) are added to the samples for ANN training. And on this basis, an ANN model is established to implement higher precise back-analysis of initial ground stress. A practical application case shows that the relative error between the inversed ground stress and observed value is mostly less than 10 %, which can meet the need of engineering design and construction requirements.展开更多
The 3D geological modeling is the prerequisite and core foundation for Digital Mine.Although this new technology brings new opportunities and motivation for the mineral exploration industry,it still has many difficult...The 3D geological modeling is the prerequisite and core foundation for Digital Mine.Although this new technology brings new opportunities and motivation for the mineral exploration industry,it still has many difficulties to be solved in this area.Based on the characteristics of mine data and the aim of Digital Mine construction,this paper introduces a theory including multi-source data coupling,multi-modeling methods integration,multi-resolution visualization and detection,and multidimensional data analysis and application.By analyzing problems such as the uncertainty in each step of the modeling process,we designed a novel modeling method that can be applied to the complex geological body modeling,mineral resource/reserve estimation,and the mining exploration engineering.Along with the process of mine exploration,development,and reclamation,3D modeling undergoes the process of"construction-simulation-revision"during which the 3D model is able to be dynamically updated and gradually improved.Based on the result of practical utilization,it is proven that the methodology introduced by this paper can be used to build an effective 3D model by fully using the mining data under the control of spatial information quality evaluation.Our experiments show that such a 3D model can be used to evaluate the mine resource and provide the scientific evidence to improve mining efficiency during the various stages of evolvement process in mine.展开更多
To solve the problems encountered in practical processes of magneto-optical sensing, the infinitesimal distributed-parameter model and finite-element accumulation of different dielectric properties of micromaterials w...To solve the problems encountered in practical processes of magneto-optical sensing, the infinitesimal distributed-parameter model and finite-element accumulation of different dielectric properties of micromaterials were used to describe the evolution of light polarization states, instead of the previously commonly used method of lumped-parameter simulation, thus essentially explaining the mechanism of sensing, magneto-optical effects, and related factors, and achieving multiphysics coupling using the COMSOL finite-element analysis method. Considering the cases of the Faraday effect without and with line birefringence, the magneto-optical effect and output characteristics of an infinitesimal magneto-optical sensor were simulated and studied. The results verified the effectiveness of the infinitesimal sensor model. Because the magnetic field, stress, and temperature changes alter the dielectric properties of magneto-optical materials, the finite-element accumulation method lays a good foundation for research on theoretical analysis and performance of magneto-optical sensors affected by factors such as the magnetic field, temperature, and stress.展开更多
Hepatitis C virus （HCV） is a blood-borne infection that can lead to progressive liver fail- ure, cirrhosis, hepatocellular carcinoma and death. A deterministic mathematical model for assessing the impact of daily in...Hepatitis C virus （HCV） is a blood-borne infection that can lead to progressive liver fail- ure, cirrhosis, hepatocellular carcinoma and death. A deterministic mathematical model for assessing the impact of daily intravenous drug misuse on the transmission dynamics of HCV is presented and analyzed. A threshold quantity known as the reproductive number has been computed. Stability of the steady states has been investigated. The dynamical analysis reveals that the model has globally asymptotically stable steady states. The impact of daily intravenous drug misuse on the transmission dynamics of HCV has been discussed through the basic reproductive number and numerical simulations.展开更多
基金Project(07JJ1010) supported by the Hunan Provincial Natural Science Foundation of China for Distinguished Young ScholarsProjects(61073037,60773013) supported by the National Natural Science Foundation of China
文摘Most existing work on survivability in mobile ad-hoc networks(MANETs) focuses on two dimensional(2D) networks.However,many real applications run in three dimensional(3D) networks,e.g.,climate and ocean monitoring,and air defense systems.The impact on network survivability due to node behaviors was presented,and a quantitative analysis method on survivability was developed in 3D MANETs by modeling node behaviors and analyzing 3D network connectivity.Node behaviors were modeled by using a semi-Markov process.The node minimum degree of 3D MANETs was discussed.An effective approach to derive the survivability of k-connected networks was proposed through analyzing the connectivity of 3D MANETs caused by node misbehaviors,based on the model of node isolation.The quantitative analysis of node misbehaviors on the survivability in 3D MANETs is obtained through mathematical description,and the effectiveness and rationality of the proposed approach are verified through numerical analysis.The analytical results show that the effect from black and gray attack on network survivability is much severer than other misbehaviors.
基金Innovation Fund of Harbin,China (No.2006RFQXG036)
文摘Equivalent integrated finite element method is a canonical and efficient modeling method in dynamic analysis of complex mechanism. The key of establishing dynamic equations of spatial mechanism by the method is to confirm Jacobian matrix reflecting relations of all joints,nodes,and generalized coordinates,namely,relations of second-order and corresponding third-order conversion tensors. For complex motion relations of components in a parallel robot,it gives second-order and third-order conversion tensors of dynamic equations for the 6-HTRT parallel robot based on equivalent integrated finite element method. The method is suitable for the typical robots whose positions of work space and sizes of mechanism are different. The solving course of the method is simple and convenient,so the method lays the foundation of dynamic analysis for robots.
文摘From the simulation software selection, meteorological data collection, model, boundary conditions, calculation setting and evaluation indicators, the paper summarize simulation method of wind, light and sound, summarize three kinds of environmental. The paper study on optimization analysis method of green building from four aspects of building orientation, architectural form, architectural layout and indoor environment, and puts forward the optimization scheme of the typical simulation analysis of simple questions; provide guidance for optimizing the design of green building. Finally, ECOTECT can adapt to the current domestic engineering design and consulting on green building simulation and design requirements, and has a broad application prospect.
基金Innovative Research Groups of the National Natural Science Foundation of China (No.51021004)National Science Foundation of China (No. 51079096)Program for New Century Excellent Talents in University (No. NCET-08-0391)
文摘A new back-analysis method of ground stress is proposed with comprehensive consideration of influence of topography, geology and nonlinear physical mechanical properties of rock on ground stress. This method based on non-uniform rational B-spline (NURBS) technology provides the means to build a refined three-dimensional finite element model with more accurate meshing under complex terrain and geological conditions. Meanwhile, this method is a back-analysis of ground stress with combination of multivariable linear regression model and neural network (ANN) model. Firstly, the regression model is used to fit approximately boundary loads. Regarding the regressed loads as mean value, some sets of boundary loads with the same interval are constructed according to the principle of orthogonal design, to calculate the corresponding ground stress at the observation positions using finite element method. The results (boundary loads and the corresponding ground stress) are added to the samples for ANN training. And on this basis, an ANN model is established to implement higher precise back-analysis of initial ground stress. A practical application case shows that the relative error between the inversed ground stress and observed value is mostly less than 10 %, which can meet the need of engineering design and construction requirements.
基金financially supported by National Natural Science Foundation of China(Grant Nos.41272276,51174289,41102180&40742013)Innovation Research Team Program of Ministry of Education(IRT1085)+2 种基金China National Scientific and Technical Support Program(Grant Nos.201105060-06&2012BAB12B03)National Geological Survey Program(Grant No.shui[2012]-01-035-036)Fundamental Research Funds for the Central Universities(Grant No.2010YD 02)
文摘The 3D geological modeling is the prerequisite and core foundation for Digital Mine.Although this new technology brings new opportunities and motivation for the mineral exploration industry,it still has many difficulties to be solved in this area.Based on the characteristics of mine data and the aim of Digital Mine construction,this paper introduces a theory including multi-source data coupling,multi-modeling methods integration,multi-resolution visualization and detection,and multidimensional data analysis and application.By analyzing problems such as the uncertainty in each step of the modeling process,we designed a novel modeling method that can be applied to the complex geological body modeling,mineral resource/reserve estimation,and the mining exploration engineering.Along with the process of mine exploration,development,and reclamation,3D modeling undergoes the process of"construction-simulation-revision"during which the 3D model is able to be dynamically updated and gradually improved.Based on the result of practical utilization,it is proven that the methodology introduced by this paper can be used to build an effective 3D model by fully using the mining data under the control of spatial information quality evaluation.Our experiments show that such a 3D model can be used to evaluate the mine resource and provide the scientific evidence to improve mining efficiency during the various stages of evolvement process in mine.
基金supported by the National Natural Science Foundation of China(Grant No.51277066)
文摘To solve the problems encountered in practical processes of magneto-optical sensing, the infinitesimal distributed-parameter model and finite-element accumulation of different dielectric properties of micromaterials were used to describe the evolution of light polarization states, instead of the previously commonly used method of lumped-parameter simulation, thus essentially explaining the mechanism of sensing, magneto-optical effects, and related factors, and achieving multiphysics coupling using the COMSOL finite-element analysis method. Considering the cases of the Faraday effect without and with line birefringence, the magneto-optical effect and output characteristics of an infinitesimal magneto-optical sensor were simulated and studied. The results verified the effectiveness of the infinitesimal sensor model. Because the magnetic field, stress, and temperature changes alter the dielectric properties of magneto-optical materials, the finite-element accumulation method lays a good foundation for research on theoretical analysis and performance of magneto-optical sensors affected by factors such as the magnetic field, temperature, and stress.
文摘Hepatitis C virus （HCV） is a blood-borne infection that can lead to progressive liver fail- ure, cirrhosis, hepatocellular carcinoma and death. A deterministic mathematical model for assessing the impact of daily intravenous drug misuse on the transmission dynamics of HCV is presented and analyzed. A threshold quantity known as the reproductive number has been computed. Stability of the steady states has been investigated. The dynamical analysis reveals that the model has globally asymptotically stable steady states. The impact of daily intravenous drug misuse on the transmission dynamics of HCV has been discussed through the basic reproductive number and numerical simulations.
