基于粗糙集——粒子群神经网络的建设项目安全预测研究

回顾施工项目安全管理和安全管理研究现状,建立建设项目安全管理指标体系。利用人工神经网络非线性函数逼近能力,对项目风险因素程度预测。针对该网络当数据量大时,其结构复杂、收敛慢,易陷入局部最优的缺点,引入粗糙集对影响建设项目安全目标的不确定性因素进行约简,找出最小不确定性风险因素集,大大简化网络输入信息的表达空间维数。并结合粒子群算法收敛速度快、全局最优的寻优能力强的优点,建立基于粗糙集——粒子群神经网络的建设项目安全预测系统。通过实例验证该系统的科学性和有效性。     

基于粗糙集-人工神经网络的航空安全文化评价模型研究

根据航空运输企业安全生产系统的特征,制定相对科学的、适用的安全文化评价指标体系。将粗糙集、人工神经网络方法应用于航空安全文化评价研究。首先,通过问卷调查与粗糙集方法相结合,对安全文化评价指标信息表进行设定。利用粗糙集的属性约简功能,确定航空安全文化的核心要素;其次,利用人工神经网络对约简后指标权重进行计算;经过仿真实验,训练后的神经网络较好地获取并保存了安全文化评价的知识和经验,能够较为准确地对航空安全文化进行评价。     

A FUZZY SETS MODEL FOR MEASURING THE EFFECTIVENESS OF PUBLIC PARTICIPATION IN WATER RESOURCES PLANNING1

Mathematical modeling of complex water resources System problems, particularly water pollution control, is aided by fizzy set theory. Public participation in large scale federally funded water resources and pollution control projects is now a federal requirement and practice of various planning agencies. However, no systems based model for quantifying and measuring the effectiveness of public participation is known to exist. In this paper, we report a fuzzy set based model developed for doing this in areawide water resources planning The model is essentially cascade in nature and employs the concepts of fuzzy pessimistic and optimistic aggregations to cluster and analyze the evaluations of the basic factors. Sample computations of the model are provided.     

EVALUATION OF ALTERNATIVES TO THE GARRISON DIVERSION UNIT1

ABSTRACT: The Garrison Diversion Unit is a multipurpose water resources project which is currently under development for the purpose of diverting water from the Missouri River basin to irrigate farmland in North Dakota. Due to the objections raised by various interest groups, the project has recently been reviewed by the International Joint Commission. This article surveys the background to the project and the various alternatives that have been proposed. By utilizing recently developed fuzzy set techniques, the proposed alternatives are evaluated and a plausible solution is proposed. The results of the study indicate that it may be advisable to remove the Souris Loop irrigation area from the Garrison project but the environmental impacts of the study may preclude the implementation of any alternative that can affect Canada. These findings are in partial agreement with the recommendations of the International Joint Commission.     

基于直觉模糊集的城市供水安全预警评价模型

为了更好地评价城市供水安全预警的等级,基于直觉模糊集理论,建立城市供水安全预警评价模型。模型选取12个评价指标构成属性集,预警等级划分标准构成评价等级集,再将二者转换为直觉模糊数,以此构成直觉模糊决策矩阵,并综合主、客观权重的优势得到组合权重,以此计算样本综合值,最后分析指标权重变化对于评价结果影响的灵敏度。实例计算结果表明:基于直觉模糊集的城市供水安全预警评价与可拓物元分析法的结果总体接近,2006—2009年供水安全预警等级处于重警或中警等级,2009年以后预警等级降低并基本稳定在无警这一等级。不同指标的敏感性分析有助于提高权重的准确性。     

基于可变模糊集理论的硫化矿炸药自爆危险性评价

为了判定某高硫矿山的炸药自爆危险性,采用可变模糊集理论对矿山中的黄铁矿含量、装药时间等8个影响炸药自爆的因素进行评价。根据可变模糊评价模型确定指标评价区间矩阵Iab、可变范围评价区间Icd和点值矩阵M,利用熵权法确定各影响因素权重,并根据指标特征值xij,Mih得到综合相对隶属度矩阵,结合判断准则得出该矿山炸药自爆危险性等级。研究结果表明:该矿山的炸药自爆危险等级为Ⅱ级,自爆危险性一般,与实际生产情况相符,可变模糊集理论在评价炸药自爆危险性时具有有效性。     

Finding upper-level sets in cellular surface data using echelons and saTScan

Across a spectrum of contemporary contexts from public health to landscape ecology and natural resources, there is need for objective determination of elevated occurrence in phenomena such as disease incidence and biodiversity. Occurrences of such phenomena constitute response surfaces, but data regarding the surface is typically acquired in a cellular framework. The cells may comprise a regular grid, or may be of irregular shapes such as counties in which statistics are collected. Echelons are a topologically based approach to systematic determination of spatial structure in a step surface. Spatial scan statistics are a probability-based approach to the same issue when interest lies in a rate variable. Here we examine the use of echelons both separately and in conjunction with the SaTScan implementation of spatial scan statistics for purposes of determination and visualization of upper-level sets. Consideration is given to both conventional geographic space and to the cellular pseudo-space of contingency tables for ordered categorical variables. Received: August 2002 / Revised: July 2005     

Sensitivity of Systematic Reserve Selection to Decisions about Scale, Biological Data, and Targets: Case Study from Southern British Columbia

Abstract:  The identification of conservation areas based on systematic reserve-selection algorithms requires decisions related to both spatial and ecological scale. These decisions may affect the distribution and number of sites considered priorities for conservation within a region. We explored the sensitivity of systematic reserve selection by altering values of three essential variables. We used a 1:20,000–scale terrestrial ecosystem map and habitat suitability data for 29 threatened vertebrate species in the Okanagan region of British Columbia, Canada. To these data we applied a reserve-selection algorithm to select conservation sites while altering selection unit size and shape, features of biodiversity (i.e., vertebrate species), and area conservation targets for each biodiversity feature. The spatial similarity, or percentage overlap, of selected sets of conservation sites identified (1) with different selection units was ≤40%, (2) with different biodiversity features was 59%, and (3) with different conservation targets was ≥94%. Because any selected set of sites is only one of many possible sets, we also compared the conservation value (irreplaceability) of all sites in the region for each variation of the data. The correlations of irreplaceability were weak for different selection units (0.23 ≤ r ≤ 0.67), strong for different biodiversity features ( r = 0.84), and mixed for different conservation targets ( r = 0.16; 0.16; 1.00). Because of the low congruence of selected sites and weak correlations of irreplaceability for different selection units, recommendations from studies that have been applied at only one spatial scale must be considered cautiously.     

济南地下水资源系统多目标管理模型及模糊带权方法

根据济南地下水资源系统管理研究,建立了济南地下水资源系统多目标管理模型;利用模糊数学理论,提出一种模糊带权方法,它能同时解决互为矛盾、互为竞争的各目标之间的不可比性和主次性问题。实际计算表明,本文建立的多目标管理模型和提出的方法是合理的和有效的。     

基于关系矩阵和模糊集合的煤与瓦斯突出综合评价

用关系矩阵确定表征各影响因素在煤与瓦斯突出地位中的因素活动性指数，并利用模糊集合理论中的隶属变化量化手段确定单因素分级指数，最后综合两种指数求得反映煤与瓦斯突出的危险性系数。此方法在平顶山煤业集团预测煤与瓦斯突出中的应用表明：基于关系矩阵和模糊集合的煤与瓦斯突出综合评价是可行的。