等高线是地形图上的重要要素之一,其化简过程需要兼顾主要地形结构特征的保持、数据精度的控制以及相交和视觉混淆的避免等问题,现有研究大多没有同时兼顾这3个方面。针对上述问题,本文在现有方法使用的误差带的基础上,进一步引入隔离...等高线是地形图上的重要要素之一,其化简过程需要兼顾主要地形结构特征的保持、数据精度的控制以及相交和视觉混淆的避免等问题,现有研究大多没有同时兼顾这3个方面。针对上述问题,本文在现有方法使用的误差带的基础上,进一步引入隔离带的概念,并对它们在几何中的定义进行数学描述,提出将空间拓扑条件应用于等高线化简的策略。根据这一策略,对谷地弯曲选取(Valley Bend Selection,VBS)算法和Douglas-Peucker(DP)算法进行改进,从而得到空间拓扑条件控制下的VBS(Spatial-Topologic-Condition-Controlled VBS,STCC-VBS)算法和空间拓扑条件控制下的DP(Spatial-Topologic-Condition-Controlled DP,STCC-DP)算法。最后,将这2种方法应用于1:5万比例尺地形图等高线化简生成1:10万比例尺地形图等高线的任务中,并与现有的2种单纯以误差带控制的等高线化简方法进行对比。实验结果表明,STCC-VBS算法和STCC-DP算法都有效避免了相交问题,同时以改进前的方法为参考,在算法参数相同的情况下,分别在节点约减率降低8.33%和2.06%同时,使等高线偏移率降低了22.97%和12.65%,化简效果得到显著改善。其中,STCC-VBS算法在约减54.58%的节点的同时,仍能使地形特征线保持率达到94.73%,在有效约减数据量的前提下,较好地保持了主要地形特征。2种算法在效率方面均优于2种单纯以误差带控制的等高线化简方法。展开更多
The present paper deals with a multiobjective optimization of truss topology by either Sequential Linear Programming （SLP） method or Linear Programming （LP） method. The ground structure approach is often used to s...The present paper deals with a multiobjective optimization of truss topology by either Sequential Linear Programming （SLP） method or Linear Programming （LP） method. The ground structure approach is often used to solve this kind of design problems. In this paper, the topology optimization is formulated as a Multiobjective Optimization Problem （MOP）, which is to find the cross-sectional area of truss members, such that both the total volume of members and the weighted mean compliance are minimized. Based upon the Karush-Kuhn-Tucker conditions （the optimality condition）, the Pareto optimal front of this problem can be obtained theoretically. The truss topology optimization under multiple load cases can be solved by the SLP. On the other hand, the LP such as the Simplex method or the interior point method can be applied to find one of the Pareto optimal solutions of the MOP under single load case. The applications of either the SLP or the LP are illustrated in numerical examples with discussion on characteristics of design results.展开更多
In this paper, some existence theorems of a solution for generalized vector quasivariational-like inequalities without any monotonity conditions in a noncompact topological space setting are proven by the maximal elem...In this paper, some existence theorems of a solution for generalized vector quasivariational-like inequalities without any monotonity conditions in a noncompact topological space setting are proven by the maximal element theorem.展开更多
This paper is focused on formability of multi-agent systems （MASs）. The problem is concerned with the existence of a protocol that has the ability to drive the MAS involved to the desired formation, and thus, is of ...This paper is focused on formability of multi-agent systems （MASs）. The problem is concerned with the existence of a protocol that has the ability to drive the MAS involved to the desired formation, and thus, is of essential importance in designing formation protocols. Formability of an MAS depends on several key factors： agents＇ dynamic structures, connectivity topology, properties of the desired formation and the admissible control set. Agents of the MASs considered here are described by a general continuous linear time-invariant （LTI） model. By using the matrix analysis and algebraic graph theory, some necessary and sufficient conditions on formability of LTI-MASs are obtained. These conditions characterize in some sense the relationship of formability, connectivity topology, formation properties and agent dynamics with respect to some typical and widely used admissible protocol sets.展开更多
Polyoxometalates （POMs）, with their attractive topological and electronic properties, have been demonstrated over the last few decades to be efficient catalysts for many reactions. In a new direction, POMs having a ...Polyoxometalates （POMs）, with their attractive topological and electronic properties, have been demonstrated over the last few decades to be efficient catalysts for many reactions. In a new direction, POMs having a purely inorganic framework are now being explored as efficient catalysts for water oxidation. This review focuses on very recent developments of POM-based catalysts for water oxidation to O2. In the very extensive family of POMs, tetra-core sandwich-type Ru- and Co-containing POM complexes, namely [Ru404（OH）2（H20）4（y-SiW10O36）2]10- and [CO4（H2O）2（a-PWgO34）2]10- exhibit the ability to facilitate water oxidation under electrocatalytic and/or photocatalytic conditions. However, it is concluded that much work still needs to be done to explain the catalytic mechanisms and optimize these catalytic systems. In addition, recent trends in using ionic liquids as media to modify the electrolytic environment and enhance water oxidation are highlighted.展开更多
文摘等高线是地形图上的重要要素之一,其化简过程需要兼顾主要地形结构特征的保持、数据精度的控制以及相交和视觉混淆的避免等问题,现有研究大多没有同时兼顾这3个方面。针对上述问题,本文在现有方法使用的误差带的基础上,进一步引入隔离带的概念,并对它们在几何中的定义进行数学描述,提出将空间拓扑条件应用于等高线化简的策略。根据这一策略,对谷地弯曲选取(Valley Bend Selection,VBS)算法和Douglas-Peucker(DP)算法进行改进,从而得到空间拓扑条件控制下的VBS(Spatial-Topologic-Condition-Controlled VBS,STCC-VBS)算法和空间拓扑条件控制下的DP(Spatial-Topologic-Condition-Controlled DP,STCC-DP)算法。最后,将这2种方法应用于1:5万比例尺地形图等高线化简生成1:10万比例尺地形图等高线的任务中,并与现有的2种单纯以误差带控制的等高线化简方法进行对比。实验结果表明,STCC-VBS算法和STCC-DP算法都有效避免了相交问题,同时以改进前的方法为参考,在算法参数相同的情况下,分别在节点约减率降低8.33%和2.06%同时,使等高线偏移率降低了22.97%和12.65%,化简效果得到显著改善。其中,STCC-VBS算法在约减54.58%的节点的同时,仍能使地形特征线保持率达到94.73%,在有效约减数据量的前提下,较好地保持了主要地形特征。2种算法在效率方面均优于2种单纯以误差带控制的等高线化简方法。
文摘The present paper deals with a multiobjective optimization of truss topology by either Sequential Linear Programming （SLP） method or Linear Programming （LP） method. The ground structure approach is often used to solve this kind of design problems. In this paper, the topology optimization is formulated as a Multiobjective Optimization Problem （MOP）, which is to find the cross-sectional area of truss members, such that both the total volume of members and the weighted mean compliance are minimized. Based upon the Karush-Kuhn-Tucker conditions （the optimality condition）, the Pareto optimal front of this problem can be obtained theoretically. The truss topology optimization under multiple load cases can be solved by the SLP. On the other hand, the LP such as the Simplex method or the interior point method can be applied to find one of the Pareto optimal solutions of the MOP under single load case. The applications of either the SLP or the LP are illustrated in numerical examples with discussion on characteristics of design results.
基金the National Natural Science Foundation of China (10171118)the Education Committee project Research Foundation of Chongqing (030801)and the Science Committee project Research Foundation of Chongqing (8409)
文摘In this paper, some existence theorems of a solution for generalized vector quasivariational-like inequalities without any monotonity conditions in a noncompact topological space setting are proven by the maximal element theorem.
基金supported by the National Nature Science Foundation of China under Grants Nos.60934006 and 61104136the Shandong Provincial Natural Science Foundation under Grant No.ZR2010FQ002+1 种基金the School Foundation of Qufu Normal University under Grant No.XJ200913the Scientific Research Foundation of Qufu Normal University
文摘This paper is focused on formability of multi-agent systems （MASs）. The problem is concerned with the existence of a protocol that has the ability to drive the MAS involved to the desired formation, and thus, is of essential importance in designing formation protocols. Formability of an MAS depends on several key factors： agents＇ dynamic structures, connectivity topology, properties of the desired formation and the admissible control set. Agents of the MASs considered here are described by a general continuous linear time-invariant （LTI） model. By using the matrix analysis and algebraic graph theory, some necessary and sufficient conditions on formability of LTI-MASs are obtained. These conditions characterize in some sense the relationship of formability, connectivity topology, formation properties and agent dynamics with respect to some typical and widely used admissible protocol sets.
基金financed by the Australian Research Council Discovery Scheme and UNSW Science Faculty Research Grants Program
文摘Polyoxometalates （POMs）, with their attractive topological and electronic properties, have been demonstrated over the last few decades to be efficient catalysts for many reactions. In a new direction, POMs having a purely inorganic framework are now being explored as efficient catalysts for water oxidation. This review focuses on very recent developments of POM-based catalysts for water oxidation to O2. In the very extensive family of POMs, tetra-core sandwich-type Ru- and Co-containing POM complexes, namely [Ru404（OH）2（H20）4（y-SiW10O36）2]10- and [CO4（H2O）2（a-PWgO34）2]10- exhibit the ability to facilitate water oxidation under electrocatalytic and/or photocatalytic conditions. However, it is concluded that much work still needs to be done to explain the catalytic mechanisms and optimize these catalytic systems. In addition, recent trends in using ionic liquids as media to modify the electrolytic environment and enhance water oxidation are highlighted.
