优选地震救灾路径的图与模糊集算法

由于在大地震的紧急救灾期，交通网络具有明显的结构变动性，传统的最短路算法设计出的路线难以满足救灾在时间、安全性与通行质量方面的要求。为了解决这一问题，考虑了有关的因素，基于模糊评价，对交通网络图中的长度权进行了修正；并增加了2个新的约束，然后综合应用图论与模糊极值的理论方法，建立了2个以最大限度地保障运行体的完整性与缩短运行时间为主要目标的，在多权图上优选路线的算法。该算法可较好地满足紧急救灾路线优化设计的需要。     

基于代理模型的制导子弹气动外形优化设计

目的 针对传统气动外形优化设计依赖于高精度仿真耗时过长的问题，为有效提高气动优化设计的效率，提出一种基于代理模型的气动外形优化方法。方法 以12.7 mm制导子弹为研究对象，通过CFD仿真，分析尾翼收缩段长度、弹底半径和尾翼收缩扩张段交界处半径对制导子弹飞行过程中阻力系数的影响。基于代理模型技术，综合运用试验设计、参数化建模、CFD技术和四阶响应面模型，构建制导子弹气动外形优化设计代理模型，以制导子弹飞行过程中的最小阻力系数为优化目标，结合遗传算法对制导子弹外形参数进行优化。结果 对比四阶多项式响应面和Kriging模型建立的代理模型预测精度，与测试样本点CFD仿真计算结果相比，四阶响应面代理模型阻力系数预测值的平均误差为0.386%。表明四阶响应面代理模型能够有效替代CFD仿真，可用于预测不同外形参数下制导子弹的阻力系数。结论 相对于最初的制导子弹外形，制导子弹的阻力系数下降了14.59%，有效减少子弹飞行过程中的能量损失和缩短了优化时长。该方法在保证精度的前提下，减少了制导子弹的设计周期，为相关工程应用与研究提供了一定的参考。     

板筋结构强度计算及最优化设计

板筋结构是除尘器的重要结构形式，其结构的强度与除尘器的安全性有着密切的关系。介绍了板筋结构在除尘器应用中的荷栽、强度计算方法，并利用VB软件进行板筋结构最优化设计。     

Surrogates for Macrofungi and Mosses in Reservation Planning

Abstract: Our knowledge of cryptogam taxonomy and species distributions is currently too poor to directly plan for their conservation. We used inventory data from four distinct vegetation types, near Hobart Tasmania, to address the proposition that vegetation type, vascular plant taxon composition, and environmental variables can act as surrogates for mosses and macrofungi in reservation planning. The four vegetation types proved distinct in their taxon composition for all macrofungi, mosses, and vascular plants. We tested the strength of the relationships between the composition of cryptogam taxonomic groups and vascular plant composition and between the environmental variables and canopy cover. Taxon composition of woody vascular plants and vascular plants was the best predictor of the taxon composition of mosses and macrofungi. Combinations of environmental variables and canopy cover were also strong predictors of the taxon composition of mosses and macrofungi. We used an optimization routine for vascular plant taxa and woody plant species and determined the representation of cryptogam taxa in these selections. We identified sites with approximately 10% and 30% of the greatest proportions of vascular plants and woody vascular plants and calculated representation of mosses and macrofungi at these sites. We compared the results of these site selections with random site selections and random selections stratified by vegetation type. Random selection of sites by vegetation type generally captured more cryptogams than site selection by vascular plants at the 10% level. Vascular plant and woody plant taxon composition, vegetation type, and environmental and structural characteristics, all showed promise as surrogates for capturing common cryptogams in reserve systems.     

MODELING MULTIPLE-USE IN NATURAL AREAS: PART 1 - THE BASIC FORMULATION1

ABSTRACT: This paper presents a mathematical model of multiple-use in natural areas. The model represents a unified system for the assessment of cases where some form of development is proposed for relatively natural areas. The focus of the model system is a benefit-cost analysis. Provisions for the full consideration of easily measured monetary costs and benefits as well as semitangible benefits accruing from environment-related activities such as outdoor recreation are contained in the model. Means for incorporating desirability as a measure of aesthetics, uniqueness, and environmental quality into the evaluation are provided. Serveral types of constraints have been imposed on the system to increase model realism. A family of compatibility constraints was designed to limit inter-use conflicts arising from incompatible activities. A form of the gradient optimization algorithm was utilized to facilitate the evaluation. The model system has application in a wide range of problems frequently encountered in environmental planning and assessment as well as natural resources management.     

ASSESSMENT ANALYSIS FOR WATER SUPPLY ALTERNATIVES1

ABSTRACT Providing adequate water supplies of good quality is becoming a serious problem in many areas of the United States. Some of the alternatives proposed for meeting the growing shortage of clean-water or cheap-water are reallocation, reuse, and importation. This paper outlines a methodology to assess all of these water supply alternatives by examining the amount and time-staging for development of water sources. In conceptualizing the problem, sources of supply are classified in three categories: primary or base supplies, secondary or effluent supplies, and supplementary or imported supplies. A model of the water system is formulated as a “transportation problem” in linear programming depicting the possible sources of supply which can be used to satisfy the requirements of various water users. The optimizing objective in the model is to minimize the cost of water under various assumptions for operating the system. A case study of the Salt Lake Qty, Utah, area is used to illustrate the application of the model in obtaining optimal water supply allocations for projected future demands. Assessment of alternatives in the study include redistribution of supplies, time-staging of supplies and related treatment facilities, and sensitivity of allocations to changes in costs.     

基于居民行为的三生空间识别与优化分析框架

“三生空间”是人类经济、社会活动的基本载体,也是人类精神和文化需求的空间反映。识别“三生空间”范围、了解居民“三生”需求、调整“三生空间”供给、统筹“三生空间”功能是国土空间规划内容的核心,也是当前实现治理能力现代化和新时代高质量发展的重要前提。从当前国土空间规划编制的需求出发,依据行为科学和行为地理学等理论方法,探讨了“三生行为”与“三生空间”的理论关联,进而遵循“需求分析与空间识别—问题诊断与目标确定—作用机理与耦合关系—空间优化与政策建议”分析思路,构建基于居民行为的“三生空间”优化分析框架。将居民行为研究与空间供需结合起来,可为国土空间规划工作提供“人本化”的理论框架与新思路。     

基于烦恼改善程度优选噪声控制方案

影响噪声烦恼的声学参量较多,然而在传统噪声控制工程中,往往仅根据A计权声压级所需降低量进行控制方案设计,未能从烦恼改善程度优选方案.为此,本研究提出一种基于烦恼改善程度优选噪声控制方案的方法,并将该方法应用于变电站声屏障噪声控制方案的比选.结果表明,同一声屏障方案对不同关心点噪声烦恼的改善程度差异较大,A计权声压级降低量最大的声屏障方案对噪声烦恼的改善效果未必最好.因此,噪声控制工程设计中,宜根据所关心的声环境保护目标与噪声源的相对位置,选取对保护目标处噪声烦恼改善程度较大的方案.     

基于理想点法的加筋板屈曲承载力优化

目的针对加筋板在使用工况中易发生屈曲和结构失稳,提出一种基于理想点法的屈曲承载力优化设计方法。方法以加筋板的屈曲承载力最大和结构质量最小为目标,以加筋板的屈曲、最大vonMises应力和筋条压损等为约束条件,并利用理想点法将多目标优化问题转化为单目标优化问题。基于ANSYS参数化建模技术,构建屈曲分析、优化设计一体化分析与设计模型,并采用单目标优化算法——DOWNHILL SIMPLEX算法实施了优化分析。结果优化后结构质量从0.195 kg增加到0.24 kg,增加了23%,结构承载力从129.4 k N提升到235.84 kN,提高了82%。结论通过优化能够获得结构性能折中的方案,可为加筋板结构设计应用提供参考。