Convex decomposition of concave clouds for the ultra-short-term power prediction of distributed photovoltaic system

Concave clouds will cause miscalculation by the power prediction model based on cloud features for distributed photovoltaic( PV) plant. The algorithm for decomposing concave cloud into convex images is proposed. Adopting minimum polygonal approximation( MPP) to demonstrate the contour of concave cloud,cloud features are described and the subdivision lines of convex decomposition for the concave clouds are determined by the centroid point scattering model and centroid angle function,which realizes the convex decomposition of concave cloud. The result of MATLAB simulation indicates that the proposed algorithm can accurately detect cloud contour corners and recognize the concave points. The proposed decomposition algorithm has advantages of less time complexity and decomposition part numbers compared to traditional algorithms. So the established model can make the convex decomposition of complex concave clouds completely and quickly,which is available for the existing prediction algorithm for the ultra-short-term power output of distributed PV system based on the cloud features.

Matrix decomposition and Lagrangian dual method for discrete portfolio optimization under concave transaction costs

In this paper,the discrete mean-variance model is considered for portfolio selection under concave transaction costs.By using the Cholesky decomposition technique,the convariance matrix to obtain a separable mixed integer nonlinear optimization problem is decomposed.A brand-and-bound algorithm based on Lagrangian relaxation is then proposed.Computational results are reported for test problems with the data randomly generated and those from the US stock market.

EXISTENCE OF MULTIPLE SOLUTIONS FOR SINGULAR QUASILINEAR ELLIPTIC SYSTEM WITH CRITICAL SOBOLEV-HARDY EXPONENTS AND CONCAVE-CONVEX TERMS

The main purpose of this paper is to establish the existence of multiple solutions for singular elliptic system involving the critical Sobolev-Hardy exponents and concave-convex nonlinearities.It is shown,by means of variational methods,that under certain conditions,the system has at least two positive solutions.

MULTIPLE POSITIVE SOLUTIONS FOR QUASILINEAR ELLIPTIC PROBLEMS INVOLVING CONCAVE-CONVEX NONLINEARITIES AND MULTIPLE HARDY-TYPE TERMS

In this paper,we deal with the existence and multiplicity of positive solutions for the quasilinear elliptic problem -△pu-k∑i=1μi(|u|p-2)/(|x-ai|p)u=|u|p*-2u+λ|u|q-2u,x ∈Ω,where ΩRN(N≥3)is a smooth bounded domain such that the diferent points ai ∈Ω,i=1,2,···,k,0≤μi<μˉ=(N-p/p)p,λ>0,1≤q<p,and p*=pN/(N-p).The results depend crucially on the parameters λ,q and μi for i=1,2,···,k.

ON SEMILINEAR ELLIPTIC EQUATIONS WITH CONCAVE AND CONVEX NONLINEARITIES IN R^N

In this paper, a class of semilinear elliptic equations with sublinear and superlinear nonlinearities in RN is studied. By making use of variational method and L∞estimation, the authors obtain some results about existence of multiple positive solutionsand asymptotic behavior of the solutions.

Multiple Solutions for a Class of Variable-Order Fractional Laplacian Equations with Concave-Convex Nonlinearity

This paper is concerned with the following variable-order fractional Laplacian equations , where N ≥ 1 and N > 2s(x,y) for (x,y) ∈ Ω × Ω, Ω is a bounded domain in RN, s(⋅) ∈ C (RN × RN, (0,1)), (-Δ)s(⋅) is the variable-order fractional Laplacian operator, λ, μ > 0 are two parameters, V: Ω → [0, ∞) is a continuous function, f ∈ C(Ω × R) and q ∈ C(Ω). Under some suitable conditions on f, we obtain two solutions for this problem by employing the mountain pass theorem and Ekeland’s variational principle. Our result generalizes the related ones in the literature.

AN ALGORITHM FOR DETERMINING CONCAVE VERTEX OF OBJECT BASED ON VECTOR PRODUCT

Concave vertex of an object is an important parameter for analyzing an object’s shape. A new algorithm for searching concave vertex is proposed in this paper. The new algorithm requires tracking the border firstly,and then uses sampling border to obtain coordinates sequence of discrete boundary points. Each sampling point of the discrete border is determined to be either concave or convex according to the value of vector product. Two inflexions can be searched by the change of concavo-convex trend. The region between two inflexions is defined as concave area. The values of distance are calculated between all boundary points on the concave area and a straight line connected by two inflexions. The boundary point corresponding to the greatest distances is max concave vertex,or the object’s concave vertex. Experimental results have proved that the new algorithm can extract the max concave vertexes of an object accurately and reliably.

Stratified Convexity &Concavity of Gradient Flows on Manifolds with Boundary

As has been observed by Morse [1], any generic vector field v on a compact smooth manifold X with boundary gives rise to a stratification of the boundary by compact submanifolds , where . Our main observation is that this stratification re-flects the stratified convexity/concavity of the boundary ?with respect to the ?v-flow. We study the behavior of this stratification under deformations of the vector field v. We also investigate the restrictions that the existence of a convex/concave traversing ?v-flow imposes on the topology of X. Let be the orthogonal projection of on the tangent bundle of . We link the dynamics of theon the boundary with the property of in X being convex/concave. This linkage is an instance of more general phenomenon that we call “holography of traversing fields”—a subject of a different paper to follow.

Property A_(UB) of Metric Spaces under Decompositions of Finite Depth

Property AUB is the notion in metric geometry which has applications in higher index problems.In this paper,the permanence property of property AUB of metric spaces under large scale decompositions of finite depth is proved.

凹凸工艺在再生纸包装设计中的应用研究

凹凸工艺与再生纸包装结合深受人们关注,随着人们环保意识的提高,再生纸包装设计运用广泛。同时,再生纸结合凹凸工艺让包装更具有一定的审美价值及实用价值。然而,在当下市场凹凸工艺的印刷及制作成本相对较高,因此该文主要研究凹凸工艺在再生纸包装设计中与3D+AI智能技术结合,以及探讨凹凸工艺在再生纸包装设计中的应用及创新方法,让凹凸工艺与再生纸包装融合在市场上有新的突破。同时,再生纸作为环保材料,不但具有可持续性和可回收利用的优点,还可以降低成本,凹凸工艺在再生纸包装设计中的应用研究有着更重要的意义。

考虑安装误差的弧齿锥齿轮凹凸齿面印痕修正

弧齿锥齿轮作为重型燃气轮机中关键的动力传动部件,其双向传动的运行特点对齿轮凹凸齿面的接触印痕提出了更高的质量要求。为了满足实际需求,通过建立齿面啮合模型,利用考虑安装误差的齿轮接触分析(error tooth contact analysis, ETCA)技术研究了一对弧齿锥齿轮凹面和凸面均为工作面时,接触印痕随安装误差变化的数值规律。同时,以齿面印痕的中点位置、长轴倾角和面积作为印痕参数化处理后的特征值,优化齿轮安装误差调整值,修正印痕的不合理之处,实现凹凸齿面印痕的一致性和重叠性。滚检实验验证了模拟印痕的准确性,该修正规律可以为弧齿锥齿轮副的安装调整提供理论依据。

基于拐点密集区凹凸波动特性的直流配网故障检测方法

基于模块化多电平换流器(modular multilevel converter,MMC)的柔性直流配电网具有不存在换相失败等优点。但换流器存在低惯性、弱阻尼等特性,导致故障电流上升速度快且峰值高,对系统危害极大。针对直流配电网发生单极接地故障难以准确选择故障馈线的问题,提出了一种基于拐点密集区凹凸波动特性的直流配网故障检测方法。首先,利用变分模态分解算法对各馈线零模电流进行分解,选取特征分量。然后,计算特征分量的二阶导数,选择拐点密集区并进行归一化处理,得到各馈线的凹凸波动性。最后,判定凹凸波动性与其他馈线相异的线路为故障线路。仿真结果表明,所提方法能够快速识别故障馈线,且受过渡电阻、采样频率、数据窗和噪声等因素影响小。

各向异性问题的多子域区域分解算法

在自然边界归化原理的基础上,构造了一种无界凹角区域上各向异性问题的多子域非重叠区域分解算法,这是两子域的非重叠区域分解法的推广.本文给出了多子域区域分解算法的离散和变分形式,利用等价性理论,通过详细的理论证明说明此算法是收敛的,且与网格参数h无关.

鄂尔多斯盆地延长组地层底面古构造定量化演化及其石油地质意义

为定量化明确延长组地层在几个关键沉积期的底面凹凸构造面貌特征,基于鄂尔多斯盆地大量钻井等资料并采用盆地模拟技术,划分4个地层单元,即长10~长8、长7、长6~长4+5和长3~长1,定量化考察延长期湖盆在各层地层单元沉积末期的底面古构造特征。结果表明:长8沉积期末,地层底面构造高程整体表现为“东高西低、南高北低”的特征,主湖盆范围的构造等高线在-600 m以下;长7地层沉积期末,整体表现为“南高北低”的古地貌特征,主湖盆范围主要分布在盆地北部、构造高程达-1 150 m以下;长4+5沉积期末,凹陷区分布在盆地西北区域、分布范围和构造高程差变小、约为200 m;长1沉积末期,地层底面构造面貌格局整体表现为“东高西低”的古地貌特征,地层底面凹凸构造高程差为300~400 m。各沉沉积期底面凹凸构造发育,缓坡构造面貌区域是油藏分布的有利区。

复杂任务区域的区域划分与覆盖路径规划

多无人机对指定区域进行巡飞探测,在地理测绘、抢险救灾等领域起到重要作用。针对多无人机对凸/非凸多边形区域的覆盖问题,开展了复杂目标区域的区域划分以及覆盖路径规划技术研究。首先,建立了无人机飞行运动模型和指定区域的边界描述。然后,针对目标区域为凸多边形与非凸多边形两种情况,同时考虑区域凸分解与集群覆盖效率优化,分别提出了基于线扫描的凸区域划分方法与基于Delaunay三角剖分的非凸区域划分方法。接着,考虑无人机运动学约束与能量消耗最小化,提出了一种最小转弯半径约束下的Z型覆盖路径。最后,通过数值仿真验证了本文所提方法的有效性。结果表明,所提方法可以对凸/非凸多边形区域实现凸划分并减小了各子区域面积差异,提高了集群总覆盖效率,覆盖路径规划方法使路径总长相较于未沿主轴覆盖时减小了26%,转弯路径占比减小了36%。

基于NX PDW的压凸包凹模镶块设计方法探讨

介绍了压凸包凸、凹模镶块的设计规范,比较了利用NX PDW的“成形镶块设计”命令和“翻孔镶块设计”命令设计压凸包凹模镶块的区别,设计实践证明,采用“翻孔镶块设计”命令设计压凸包凹模镶块更合理。

上海地区装配式住宅预制外墙与现浇混凝土竖向防水技术

针对目前装配式住宅预制外墙与现浇混凝土竖向结构连接部分存在的防水结构缺陷,从竖向刚性结构防水节点开发的角度展开研究,通过新型装配式住宅预制外墙竖向构件生产、模拟接缝施工、中试验证及效益分析,形成适用于装配式混凝土外墙的竖向刚性结构防水节点技术,可有效解决装配式混凝土外墙防水连接的渗水和漏水问题,实现与建筑结构同寿命,推动装配式建筑的可持续发展。

Symmetry Function Induced by a Convex Body

这份报纸显示出凸的身体在一个正常线性空格导致的对称功能的一些性质。在对称功能之间的一些关系由凸的身体导致了，凸的身体功能的 Minkowski 被介绍。

Martingales and Super-Martingales Relative to a Convex Set of Equivalent Measures

In the paper, the martingales and super-martingales relative to a convex set of equivalent measures are systematically studied. The notion of local regular super-martingale relative to a convex set of equivalent measures is introduced and the necessary and sufficient conditions of the local regularity of it in the discrete case are founded. The description of all local regular super-martingales relative to a convex set of equivalent measures is presented. The notion of the complete set of equivalent measures is introduced. We prove that every bounded in some sense super-martingale relative to the complete set of equivalent measures is local regular. A new definition of the fair price of contingent claim in an incomplete market is given and the formula for the fair price of Standard Option of European type is found. The proved Theorems are the generalization of the famous Doob decomposition for super-martingale onto the case of super-martingales relative to a convex set of equivalent measures.