A methodology for topology optimization based on element independent nodal density(EIND) is developed.Nodal densities are implemented as the design variables and interpolated onto element space to determine the densit...A methodology for topology optimization based on element independent nodal density(EIND) is developed.Nodal densities are implemented as the design variables and interpolated onto element space to determine the density of any point with Shepard interpolation function.The influence of the diameter of interpolation is discussed which shows good robustness.The new approach is demonstrated on the minimum volume problem subjected to a displacement constraint.The rational approximation for material properties(RAMP) method and a dual programming optimization algorithm are used to penalize the intermediate density point to achieve nearly 0-1 solutions.Solutions are shown to meet stability,mesh dependence or non-checkerboard patterns of topology optimization without additional constraints.Finally,the computational efficiency is greatly improved by multithread parallel computing with OpenMP.展开更多
When a group of mobile agents track a target,they can locate themselves and the target in a cooperative manner.To maximize the group advantage,a parallel integration strategy of cooperative target-localization(CTL)and...When a group of mobile agents track a target,they can locate themselves and the target in a cooperative manner.To maximize the group advantage,a parallel integration strategy of cooperative target-localization(CTL)and cooperative self-localization(CSL)is designed.Firstly,a global cost function containing the agents’positions and the target’s position is established.Secondly,along with the agents’positions being re-estimated during CTL,the Utransform is employed to propagate the error covariance of the position estimations among the agents.The simulation results show that,the proposal exploits more information for locating the target and the agents than the cases where CTL and CSL run separately,and the global optimal position estimations of the agents and the target are obtained.展开更多
By a complex approach,we obtain some results concerning Zygmund functions on the real line,which corresponds to some classical results about Zygmund functions on the unit circle.
The authors mainly concern the set Uf of c E C such that the power deformation z（f-（z）/z）c is univalent in the unit disk ｜z｜〈 1 for a given analytic univalent function f（z） = z ＋ a2z2 ＋ ... in the unit disk...The authors mainly concern the set Uf of c E C such that the power deformation z（f-（z）/z）c is univalent in the unit disk ｜z｜〈 1 for a given analytic univalent function f（z） = z ＋ a2z2 ＋ ... in the unit disk. It is shown that Uf is a compact, polynomially convex subset of the complex plane C unless f is the identity function. In particular, the interior of Uf is simply connected. This fact enables us to apply various versions of the X-lemma for the holomorphic family z（f（z）/z）c of injections parametrized over the interior of Uf. The necessary or sufficient conditions for Uf to contain 0 or 1 as an interior point are also given.展开更多
基金Projects(11372055,11302033)supported by the National Natural Science Foundation of ChinaProject supported by the Huxiang Scholar Foundation from Changsha University of Science and Technology,ChinaProject(2012KFJJ02)supported by the Key Labortory of Lightweight and Reliability Technology for Engineering Velicle,Education Department of Hunan Province,China
文摘A methodology for topology optimization based on element independent nodal density(EIND) is developed.Nodal densities are implemented as the design variables and interpolated onto element space to determine the density of any point with Shepard interpolation function.The influence of the diameter of interpolation is discussed which shows good robustness.The new approach is demonstrated on the minimum volume problem subjected to a displacement constraint.The rational approximation for material properties(RAMP) method and a dual programming optimization algorithm are used to penalize the intermediate density point to achieve nearly 0-1 solutions.Solutions are shown to meet stability,mesh dependence or non-checkerboard patterns of topology optimization without additional constraints.Finally,the computational efficiency is greatly improved by multithread parallel computing with OpenMP.
文摘When a group of mobile agents track a target,they can locate themselves and the target in a cooperative manner.To maximize the group advantage,a parallel integration strategy of cooperative target-localization(CTL)and cooperative self-localization(CSL)is designed.Firstly,a global cost function containing the agents’positions and the target’s position is established.Secondly,along with the agents’positions being re-estimated during CTL,the Utransform is employed to propagate the error covariance of the position estimations among the agents.The simulation results show that,the proposal exploits more information for locating the target and the agents than the cases where CTL and CSL run separately,and the global optimal position estimations of the agents and the target are obtained.
基金supported by National Natural Science Foundation of China (Grant No.11071179)
文摘By a complex approach,we obtain some results concerning Zygmund functions on the real line,which corresponds to some classical results about Zygmund functions on the unit circle.
基金Project supported by Yeungnam University(2011)(No.211A380226)the JSPS Grant-in-Aid forScientific Research(B)(No.22340025)
文摘The authors mainly concern the set Uf of c E C such that the power deformation z（f-（z）/z）c is univalent in the unit disk ｜z｜〈 1 for a given analytic univalent function f（z） = z ＋ a2z2 ＋ ... in the unit disk. It is shown that Uf is a compact, polynomially convex subset of the complex plane C unless f is the identity function. In particular, the interior of Uf is simply connected. This fact enables us to apply various versions of the X-lemma for the holomorphic family z（f（z）/z）c of injections parametrized over the interior of Uf. The necessary or sufficient conditions for Uf to contain 0 or 1 as an interior point are also given.
