高层框架分析的状态变量传递法

取高层框架柱端位移和对应的柱端力作为状态变量,利用传递矩阵和逐层分析的方法来分析以框架。文中取框架的每一层作为基本单元,建立基本单元端部的状态变量与相邻基本单元端部状态变量之间的转换关系。分析过程中,框架烽的增加仅增加上乘的次数,而待求的基本未知量的数目始终保持不变,从而提高了计算机分析问题的能力。     

集中供热系统“管-站”布局及管网优化设计方法研究

对大型集中供热系统而言,设计过程包括"管-站"布局设计和管网系统设计。根据最优化理论,提出了集中供热系统的两级优化设计模型,即第一级的"管站"布局优化和第二级的管网系统多目标优化设计模型。由于"管-站"布局优化模型属NP-hard问题(不确定问题),为寻求有效解法,对"管站"布局优化模型提出两步分级法求解,即优化过程分两步进行,第一步为分区优化,第二步为选址优化。运用本文所述方法对辽河油田振兴区集中供热改造工程,进行了优化设计,取得了较好效果。     

Dynamic Programming Algorithms for Generating Optimal Strip Layouts

This paper presents dynamic programming algorithms for generating optimal strip layouts of equal blanks processed by shearing and punching. The shearing and punching process includes two stages. The sheet is cut into strips using orthogonal guillotine cuts at the first stage. The blanks are punched from the strips at the second stage. The algorithms are applicable in solving the unconstrained problem where the blank demand is unconstrained, the constrained problem where the demand is exact, the unconstrained problem with blade length constraint, and the constrained problem with blade length constraint. When the sheet length is longer than the blade length of the guillotine shear used, the dynamic programming algorithm is applied to generate optimal layouts on segments of lengths not longer than the blade length, and the knapsack algorithm is employed to find the optimal layout of the segments on the sheet. Experimental computations show that the algorithms are efficient.     

结构静态拓扑重分析的迭代组合近似方法

提出一种拓扑修改的静态重分析的迭代组合近似方法. 这种方法基本上是两步法. 首先，将新增加的自由度通过Guyan缩减方法凝聚到原始自由度上，形成凝聚方程. 其次， 用迭代组合近似方法求出原始自由度的近似位移，从而求出原结构自由度的位移. 新增加自 由度的位移可以通过恢复得到. 通过板结构的加筋布局优化设计的数值例子表明， 该方法对拓扑修改较大时仍可得到满意的结果.     

Distinctive Features of the Flow past a Flight Vehicle Integrated with an Air-Breathing Engine at High Supersonic Velocities

The aerodynamic characteristics and distinctive features of the flow past hypersonic integral-layout flight vehicles with air-breathing engines intended for cruising atmospheric flight are experimentally investigated. The experiments were conducted on a simplified model designed with regard for the general principles of integration for vehicles of the class considered. The tests were run in a high-speed supersonic wind tunnel over the Mach and Reynolds number ranges 4 M 9 and 10⁵ Re₀ 10⁶.Balance testing was conducted, the pressure distributions over the vehicle surface were measured, the flowfield parameters were determined using a moving total-pressure tube, and flow shadowgraphs were obtained. The measured data are compared with the results of the calculations for three-dimensional inviscid flows. The effects of mounting a nacelle and contouring the internal duct are considered. The effect of the corrections on the duct flow in the absence of jet modeling is estimated.     

一种高性能硅片曝光场分布优化算法

以提高光刻机应用性能为目的,提出了一种高性能硅片曝光场分布优化算法。由芯片尺寸计算得到最佳曝光场尺寸,使其最接近于光刻机提供的曝光场最大尺寸,提高了曝光系统的利用率;引入曝光场交错分布,减少了硅片边缘曝光场的交叠,提高了光刻产率;建立产率优先和良率优先两种优化方案,实现了产率和良率的共优。以实际芯片产品的参量为例,将本算法用于曝光过程,采用产率优先标准,曝光场数量减少了10%,而内场数量基本不变,提高了光刻的产率也确保了良率;采用良率优先标准,内场数量增长了10%,总的场数也有所减少,提高了光刻良率的可靠性也确保了产率。     

Wiring edge-disjoint layouts

We consider the wiring or layer assignment problem for edge-disjoint layouts. The wiring problem is well understood for the case that the underlying layout graph is a square grid (Lipski Jr. and Preparata, 1987). In this paper, we introduce a more general approach to this problem. For an edge-disjoint layout in the plane, respectively in an arbitrary planar layout graph, we give equivalent conditions for k-layer wirability. Based on these conditions, we obtain linear-time algorithms to wire every layout in a tri-hexagonal grid or a tri-square-hexagonal grid, respectively, using at most five layers.     

卫星舱布局的半无限优化模型及最优性条件

本文以人造卫星仪器舱布局问题为背景，建立了一个半无限优化模型。应用图论、群对集合的作用、轨道等，把该问题分解为有限多个子问题，在每个子问题中克服了关于优化变量的时断时续性质。针对每个子问题分析了模型中各函数的性质，并构造了一个局部等价于子问题的极大极小问题。利用这个极大极小问题及子问题中各函数的方向可微性给出了子问题的一阶最优性条件。     

Queue layouts of iterated line directed graphs

In this paper, we study queue layouts of iterated line directed graphs. A k-queue layout of a directed graph consists of a linear ordering of the vertices and an assignment of each arc to exactly one of the k queues so that any two arcs assigned to the same queue do not nest. The queuenumber of a directed graph is the minimum number of queues required for a queue layout of the directed graph.We present upper and lower bounds on the queuenumber of an iterated line directed graph L^k(G) of a directed graph G. Our upper bound depends only on G and is independent of the number of iterations k. Queue layouts can be applied to three-dimensional drawings. From the results on the queuenumber of L^k(G), it is shown that for any fixed directed graph G, L^k(G) has a three-dimensional drawing with O(n) volume, where n is the number of vertices in L^k(G). These results are also applied to specific families of iterated line directed graphs such as de Bruijn, Kautz, butterfly, and wrapped butterfly directed graphs. In particular, the queuenumber of k-ary butterfly directed graphs is determined if k is odd.     

Linear layouts measuring neighbourhoods in graphs

In this paper we introduce the graph layout parameter neighbourhood-width as a variation of the well-known cut-width. The cut-width of a graph G=(V,E) is the smallest integer k, such that there is a linear layout ?:V→{1,…,|V|}, such that for every 1?i<|V| there are at most k edges {u,v} with ?(u)?i and ?(v)>i. The neighbourhood-width of a graph is the smallest integer k, such that there is a linear layout ?, such that for every 1?i<|V| the vertices u with ?(u)?i can be divided into at most k subsets each members having the same neighbourhood with respect to the vertices v with ?(v)>i.We show that the neighbourhood-width of a graph differs from its linear clique-width or linear NLC-width at most by one. This relation is used to show that the minimization problem for neighbourhood-width is NP-complete.Furthermore, we prove that simple modifications of neighbourhood-width imply equivalent layout characterizations for linear clique-width and linear NLC-width.We also show that every graph of path-width k or cut-width k has neighbourhood-width at most k+2 and we give several conditions such that graphs of bounded neighbourhood-width have bounded path-width or bounded cut-width.