Hierarchical art was used to solve the mixed mode placement for three dimensional （3-D） integrated circuit design. The 3-D placement flow stream includes hierarchical clustering, hierarchical 3-D floorplanning, vert...Hierarchical art was used to solve the mixed mode placement for three dimensional （3-D） integrated circuit design. The 3-D placement flow stream includes hierarchical clustering, hierarchical 3-D floorplanning, vertical via mapping, and recursive two dimensional （2-D） global/detailed placement phases. With state-of-the-art clustering and de-clustering phases, the design complexity was reduced to enhance the placement algorithm efficiency and capacity. The 3-D floorplanning phase solved the layer assignment problem and controlled the number of vertical vias. The vertical via mapping transformed the 3-D placement problem to a set of 2-D placement sub-problems, which not only simplifies the original 3-D placement problem, but also generates the vertical via assignment solution for the routing phase. The design optimizes both the wire length and the thermal load in the floorplan and placement phases to improve the performance and reliability of 3-D integrate circuits. Experiments on IBM benchmarks show that the total wire length is reduced from 15% to 35% relative to 2-D placement with two to four stacked layers, with the number of vertical vias minimized to satisfy a pre-defined upper bound constraint. The maximum temperature is reduced by 16% with two-stage optimization on four stacked layers.展开更多
A detailed analysis of an exact solvable 2-D model on a super-exchange magnetic system with frustrations in an external magnetic field is given. By means of differentiating the expression of the free energy, various t...A detailed analysis of an exact solvable 2-D model on a super-exchange magnetic system with frustrations in an external magnetic field is given. By means of differentiating the expression of the free energy, various thermodynamic properties of the system have been obtained. The variations of these quantities with applied field H and temperature T are plotted. It is found that the competition among the frustrations, H and T, results in many interesting features. Especially, three kinds of magnetic structures of the system have been obtained for various magnetic fields, and the behaviour of the magnetization as a function of temperature for a fixed magnetic field is rather peculiar.展开更多
This paper discusses the problem of the H∞ filtering for discrete time 2-D singular Roesser models (2-D SRM). The purpose is to design an observer-based 2-D singular filter such that the error system is acceptable, j...This paper discusses the problem of the H∞ filtering for discrete time 2-D singular Roesser models (2-D SRM). The purpose is to design an observer-based 2-D singular filter such that the error system is acceptable, jump modes free and stable, and satisfies a pre-specified H∞ performance level. By general Riccati inequality and bilinear matrix inequalities (BMI), a sufficient condition for the solvability of the observer-based H∞ filtering problem for 2-D SRM is given. A numerical example is provided to demonstrate the applicability of the proposed approach.展开更多
A three-dimensional ray tracing study of a whistler-mode chorus is conducted for different geomagnetic activities by using a global core plasma density model. For the upperband chorus, the initial azimuthal wave angle...A three-dimensional ray tracing study of a whistler-mode chorus is conducted for different geomagnetic activities by using a global core plasma density model. For the upperband chorus, the initial azimuthal wave angle affects slightly the projection of ray trajectories onto the plane （Z, √（x^2 ＋ y^2））, but controls the longitudinal propagation. The trajectory of the upper-band chorus is strongly associated with the plasmapause and the magnetic local time （MLT） of chorus source region. For the high geomagnetic activity, the chorus trajectory moves inward together with the plasmapause. In the bulge region, the plasmapause extends outward, while the chorus trajectory moves outward together with the plasmapause. For moderately or high geomagnetic activity, the lower-band chorus suffers low hybrid resonance （LHR） reflection before it reaches the plasmapause, leading to a weak correlation with the geomagnetic activity and magnetic local time of the chorus source region. For low geomagnetic activity, the lower-band chorus may be reflected firstly at the plasmapause instead of suffering LHR reflection, exhibiting a propagation characteristic similar to that of the upper-band chorus. The results provide a new insight into the propagation characteristics of the chorus for different geomagnetic activities and contribute to further understanding of the acceleration of energetic electron by a chorus wave.展开更多
We study the quasinormal modes（QNMs） of massless scalar perturbations to probe the van der Waals like SBH/LBH phase transition of anti-de Sitter black holes in five-dimensional（5D） Gauss–Bonnet gravity. It is fou...We study the quasinormal modes（QNMs） of massless scalar perturbations to probe the van der Waals like SBH/LBH phase transition of anti-de Sitter black holes in five-dimensional（5D） Gauss–Bonnet gravity. It is found that the signature of this SBH/LBH phase transition is detected when the slopes of the QNMs frequency change drastically and differently in small and large black holes near the critical point. The obtained results further support that the QNMs can be a dynamic probe to investigate the thermodynamic properties in black holes.展开更多
针对我国水库防洪调度系统研究与应用的现状及存在问题,提出了基于D/S模式的水库防洪调度系统的解决方案,采用Java Web Start软件实现了D/S模式的整体架构、利用图论实现了水库群的集成,应用Hibernate框架解决了业务逻辑与数据库间强耦...针对我国水库防洪调度系统研究与应用的现状及存在问题,提出了基于D/S模式的水库防洪调度系统的解决方案,采用Java Web Start软件实现了D/S模式的整体架构、利用图论实现了水库群的集成,应用Hibernate框架解决了业务逻辑与数据库间强耦合关系,并利用设计模式增强了系统的可维护性和可复用性。展开更多
基金Supported by the National Natural Science Foundation of China (Nos.60833004 and 60876026)the 3-D Floorplanning and Placement Project of the Intel Corporation
文摘Hierarchical art was used to solve the mixed mode placement for three dimensional （3-D） integrated circuit design. The 3-D placement flow stream includes hierarchical clustering, hierarchical 3-D floorplanning, vertical via mapping, and recursive two dimensional （2-D） global/detailed placement phases. With state-of-the-art clustering and de-clustering phases, the design complexity was reduced to enhance the placement algorithm efficiency and capacity. The 3-D floorplanning phase solved the layer assignment problem and controlled the number of vertical vias. The vertical via mapping transformed the 3-D placement problem to a set of 2-D placement sub-problems, which not only simplifies the original 3-D placement problem, but also generates the vertical via assignment solution for the routing phase. The design optimizes both the wire length and the thermal load in the floorplan and placement phases to improve the performance and reliability of 3-D integrate circuits. Experiments on IBM benchmarks show that the total wire length is reduced from 15% to 35% relative to 2-D placement with two to four stacked layers, with the number of vertical vias minimized to satisfy a pre-defined upper bound constraint. The maximum temperature is reduced by 16% with two-stage optimization on four stacked layers.
文摘A detailed analysis of an exact solvable 2-D model on a super-exchange magnetic system with frustrations in an external magnetic field is given. By means of differentiating the expression of the free energy, various thermodynamic properties of the system have been obtained. The variations of these quantities with applied field H and temperature T are plotted. It is found that the competition among the frustrations, H and T, results in many interesting features. Especially, three kinds of magnetic structures of the system have been obtained for various magnetic fields, and the behaviour of the magnetization as a function of temperature for a fixed magnetic field is rather peculiar.
基金Supported by National Natural Science Foundation of P.R.China (60304001, 60474078) the Science Research Development Foundation of Nanjing University of Science and Technology
文摘This paper discusses the problem of the H∞ filtering for discrete time 2-D singular Roesser models (2-D SRM). The purpose is to design an observer-based 2-D singular filter such that the error system is acceptable, jump modes free and stable, and satisfies a pre-specified H∞ performance level. By general Riccati inequality and bilinear matrix inequalities (BMI), a sufficient condition for the solvability of the observer-based H∞ filtering problem for 2-D SRM is given. A numerical example is provided to demonstrate the applicability of the proposed approach.
基金supported by National Natural Science Foundation of China(Nos.40874076,40925014)
文摘A three-dimensional ray tracing study of a whistler-mode chorus is conducted for different geomagnetic activities by using a global core plasma density model. For the upperband chorus, the initial azimuthal wave angle affects slightly the projection of ray trajectories onto the plane （Z, √（x^2 ＋ y^2））, but controls the longitudinal propagation. The trajectory of the upper-band chorus is strongly associated with the plasmapause and the magnetic local time （MLT） of chorus source region. For the high geomagnetic activity, the chorus trajectory moves inward together with the plasmapause. In the bulge region, the plasmapause extends outward, while the chorus trajectory moves outward together with the plasmapause. For moderately or high geomagnetic activity, the lower-band chorus suffers low hybrid resonance （LHR） reflection before it reaches the plasmapause, leading to a weak correlation with the geomagnetic activity and magnetic local time of the chorus source region. For low geomagnetic activity, the lower-band chorus may be reflected firstly at the plasmapause instead of suffering LHR reflection, exhibiting a propagation characteristic similar to that of the upper-band chorus. The results provide a new insight into the propagation characteristics of the chorus for different geomagnetic activities and contribute to further understanding of the acceleration of energetic electron by a chorus wave.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11647050,11675139 and 51575420the Scientific Research Program Funded by Shaanxi Provincial Education Department under Grant No 16JK1394
文摘We study the quasinormal modes（QNMs） of massless scalar perturbations to probe the van der Waals like SBH/LBH phase transition of anti-de Sitter black holes in five-dimensional（5D） Gauss–Bonnet gravity. It is found that the signature of this SBH/LBH phase transition is detected when the slopes of the QNMs frequency change drastically and differently in small and large black holes near the critical point. The obtained results further support that the QNMs can be a dynamic probe to investigate the thermodynamic properties in black holes.
文摘针对我国水库防洪调度系统研究与应用的现状及存在问题,提出了基于D/S模式的水库防洪调度系统的解决方案,采用Java Web Start软件实现了D/S模式的整体架构、利用图论实现了水库群的集成,应用Hibernate框架解决了业务逻辑与数据库间强耦合关系,并利用设计模式增强了系统的可维护性和可复用性。
