基于集对原理的天然草地分类方法

本文首次将集对原理用于天然草地分类中,以中国新疆某地区的31个天然草地为例进行计算,并将分析结果,与灰色关联度分析法、投影寻踪法以及投影寻踪动态聚类法作了对比分析。结果表明,集对法与三种方法分析结果一致,但集对法计算简单,使用方便,不受样本容量限制,且能清晰和形象地显示所属类别的程度,在多因素聚类分析中具有广阔的应用前景。     

市场需求与重庆都市游特色纪念品的开发

作者从增强特色旅游纪念品开发的可操作性出发 ,将开发看成是以链接市场需求为中心的营销策划过程 ,对重庆都市旅游特色纪念品的开发主题、要素整合与展示、相应支持性措施等提出了较具针对性的建议。在充分了解市场需求的基础上 ,将特色纪念品开发与旅游地主题形象及其要素、旅游精品开发密切结合 ,是本文主要突破点。     

AN ECONOMIST'S VIEW OF DEMAND PROJECTIONS CONSIDERING CONSERVATION1

ABSTRACT: This report places the engineering estimates of water conservation made by Sonnen and Evenson into the supply demand form used by most economists. Clarification is made concerning evaluation of conservation elasticities.     

基于投影寻踪和阶梯型曲线的水质恢复能力评价模型

利用投影寻踪、遗传算法、阶梯型曲线和水体水质恢复能力评价标准,为水体水质恢复能力综合评价提出了一种新的方法--遗传投影寻踪方法(GPPM).GPPM可把水体水质恢复能力多维评价样本指标综合成一维投影指标值.根据该投影指标值的大小就可以对该样本集进行统一评价,从而解决了各单项水体水质恢复能力评价指标评价结果的不相容问题,提高了水体水质恢复能力综合评价问题各层次的分辩力.文中给出了GPPM实施的详细步骤,并在各等级中分别产生建模样本50个、100个、500个、1 000个、1 500个和2 000个,对评价模型参数的稳定性进行了检验,结果表明所建模型是稳定的.根据黄河干流三类主要污染物BOD、氨氮和挥发酚的浓度对黄河干流的水质恢复能力进行了评价,发现整体上黄河干流的水质恢复能力较弱.GPPM不仅可以对水体水质恢复能力进行综合评价,还可以确定评价指标的权重.GPPM可广泛应用于各种水质综合评价问题中.     

用投影寻踪分类模型进行环境监测优化布点

为处理各单项环境监测指标优选结果的不相容问题,提出用投影寻踪分类模型(PPC-RAGA)进行环境监测优化布点的新方法.利用该模型可把监测点多维环境指标值综合成一维投影值,投影值越大表示该监测点的环境综合质量越差,根据投影值的大小就可对环境监测点样本集进行合理分类.采用实码加速遗传算法进行PPC-RAGA建模,简化了投影寻踪技术的实现过程,克服了目前投影寻踪技术计算复杂、编程实现困难的缺点,为投影寻踪技术在各种系统工程中的广泛应用提供了新的工具.应用实例表明,直接由样本数据驱动的PPC-RAGA模型用于环境监测优化布点,简便可行,计算结果稳健,适用性和可操作性强,在非线性、非正态高维数据分类中具有广泛的应用价值.     

Assessment of Future Drought Conditions in the Chesapeake Bay Watershed

Impacts of climate change on the severity and intensity of future droughts can be evaluated based on precipitation and temperature projections, multiple hydrological models, simulated hydrometeorological variables, and various drought indices. The objective of this study was to assess climate change impacts on future drought conditions and water resources in the Chesapeake Bay (CB) watershed. In this study, the Soil and Water Assessment Tool (SWAT) and the Variable Infiltration Capacity model were used to simulate a Modified Palmer Drought Severity Index (MPDSI), a Standardized Soil Moisture index (SSI), a Multivariate Standardized Drought Index (MSDI), along with Coupled Model Intercomparison Project Phase 5 (CMIP5) climate models for both historical and future periods (f1: 2020‐2049, f2: 2050‐2079). The results of the SSI suggested that there was a general increase in agricultural droughts in the entire CB watershed because of increases in surface and groundwater flow and evapotranspiration. However, MPDSI and MSDI showed an overall decrease in projected drought occurrences due to the increases in precipitation in the future. The results of this study suggest that it is crucial to use multiple modeling approaches with specific drought indices that combine the effects of both precipitation and temperature changes.     

归州河西沿江高切坡变形破坏及稳定性分析

为了掌握归州河以西沿江公路由于升级改造、工程开挖而产生的大量公路高切坡发育分布特征,总结其变形破坏模式,进而对其稳定性进行分析。在野外实地宏观调查、测量的基础上,通过数据处理,运用赤平投影法对调查区高切坡稳定性进行区划,其中不稳定切坡长约3.8km,占比39.6%,多发育在侏罗系遂宁组(J3s)和聂家山组(J1n)中,主要变形破坏模式为滑移型、倾倒型和剥落型,并根据其破坏模式的差异性提出相应防治对策。     

污染物浓度预测的PPR模型

采用投影寻踪回归技术的审视数据－模拟－预测新思路,对环境监测数据进行探索性分析,建立了污染物浓度预测的ＰＰＲ模型,该模型用于水污染物ＢＯＤ和ＤＯ浓度预测结果,共建模样本拟合格率为１００％,预测检验样本预测合格率达８３．３％。     

Projection pursuit cluster model and its application in water quality assessment

One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must be used. In order to overcome this issues the projection pursuit principle is introduced into water quality assessment, and projection pursuit cluster(PPC) model is developed in this study. The PPC model makes the transition from high dimension to one-dimension. In other words, based on the PPC model, multifactor problem can be converted to one factor problem. The application of PPC model can be divided into four parts: (1) to estimate projection index function Q(a) ; (2) to find the right projection direction a ; (3) to calculate projection characteristic value of the i th sample zi, and (4) to draw comprehensive analysis on the basis of zi. On the other hand, the empirical formula of cutoff radius R is developed, which is benefit for the model to be used in practice. Finally, a case study of water quality assessment is proposed in this paper. The results showed that the PPC model is reasonable, and it is more objective and less subjective in water quality assessment. It is a new method for multivariate problem comprehensive analysis.     

基于鲸鱼优化算法与投影寻踪耦合的云南省初始水权分配

论文基于公平性、效率性和可持续性原则,选取水资源开发用率等17个分水指标建立云南省初始水权分配指标体系,运用投影寻踪（Projection Pursuit, PP）技术确定云南省各州市初始水权分配水量。针对PP技术最佳投影方向难以确定的不足,利用一种新型群智能算法——鲸鱼优化算法（Whale Optimization Algorithm, WOA）寻优PP模型最佳投影方向,构建WOA-PP耦合的初始水权分配模型。通过6个典型测试函数对WOA进行仿真验证,仿真结果与文化算法（Cultural Algorithm, CA）、差分进化（Differential Evolution, DE）算法、混合蛙跳算法（Shuffled Frog Leaping Algorithm, SFLA）、布谷鸟搜索（Cuckoo Search, CS）算法、粒子群优化（Particle Swarm Optimization, PSO）算法和人工蜂群（Artificial Bee Colony, ABC）算法的寻优结果进行比较。结果表明：1）无论是单峰还是多峰函数,WOA能够探索不同的搜索空间,具有良好的开发和勘探能力,对Sphere等6个函数的寻优精度高于CA、DE、SFLA、CS、PSO和ABC算法,表现出较好的寻优精度、收敛速度、全局寻优能力与收敛稳定性。2）从WOA-PP模型初始水权分配结果及目前实行的综合法水量分配结果对比来看,2015年昭通、丽江、临沧、红河、文山、怒江两种方法的分配结果相差最小,在0.11亿~0.41亿m³之间;玉溪、普洱、大理、德宏和迪庆两种方法的分配结果相差最大,在2.06亿~4.38亿m³之间;其余州市两种方法的分配结果在1.12亿~1.61亿m³之间。2020年保山、昭通、丽江、临沧、红河、文山、怒江两种方法的分配结果相差最小,在0.02亿~0.41亿m³之间;昆明、玉溪和德宏两种方法的分配结果相差最大,分别为5.89亿、5.66亿和3.54亿m³;其余州市两种方法的分配结果在1.89亿~2.85亿m³之间。3）论文提出的初始水权分配模型及方法具有一定的可操作性和有效性,可为区域初始水权分配提供新的思路和方法。