基于Matlab的灰色系统工具箱wll的构建

灰色预测对波动性较强的序列预测效果较差,但能给出发展趋势.为了科技工作者方便地进行灰色系统的应用研究,采用层次化思想编制了基于Matlab的灰色系统工具箱wll,包含算子集合、矩阵分析、聚类分析、灰色微分方程、灰色预测模型等板块,实际使用非常方便.     

西宁市供水量的预测模型探讨

以西宁市供水量各规划水平年值为基础,在分析原始数据序列的基础上,进行供水量的预测模型研究。提出两种供水量预测方法,即一元线性回归模型及灰色预测模型,并分别进行了实例计算与分析,同时与西宁市规划部门供水量预测值进行了比较。研究结果表明,灰色预测模型较一元线性回归模型为优,可作为西宁市规划水平年的供水量预测模型     

组合优化的能源消费量预测模型

针对非等间距灰色系统预测中存在误差较大的问题,结合序列本身的特点,利用世界能源消费的历史数据,采用3种灰色预测模型与神经网络进行组合优化,建立了灰色神经网络的能源消费量组合预测模型.实证分析结果表明,提高了模型的拟合和预测精度,拓宽了应用范围.模型中对能源的消费趋势进行预测,为科学地分析能源结构提供了依据.     

组合优化的能源消费量预测模型

针对非等间距灰色系统预测中存在误差较大的问题，结合序列本身的特点，利用世界能源消费的历史数据，采用3种灰色预测模型与神经网络进行组合优化，建立了灰色神经网络的能源消费量组合预测模型。实证分析结果表明，提高了模型的拟合和预测精度，拓宽了应用范围。该模型可对能源的消费趋势进行预测，为科学分析能源结构提供依据。     

基于GM(1,1)的芜湖市人均农用地生态足迹变化研究

应用Wackernagel等提出的生态足迹方法,对芜湖市1996—2005年的人均农用地生态足迹、人均农用地生态承载力和生态赤字进行了计算;利用灰色系统预测模型建立了芜湖市人均生态足迹、生态承载力预测模型GM(1,1),经求解、检验、预测,可得到今后数年该市人均农用地生态足迹、生态承载力数据,并对灰色系统模型应用于生态足迹的预测作了可行性分析。结果显示,未来5年该区域的人均农用地生态足迹呈逐渐增大、人均农用地生态承载力呈逐渐下降的趋势,人均生态赤字也逐渐增大。     

环境风险预测数学模型

本文基于环境风险预测分析的基本思想,应用模糊图、灰色系统、非线性回归、随机过程和可靠性系统工程理论和方法,探讨了环境风险预测的数学模型。给出了环境风险预测的双向模糊图模型、灰色马尔夫预测模型及非线性回归模型,这些模型的应用为环境风险评价和环境风险管理提供了科学依据。     

用灰色系统理论GM(1,1)建立大气降水中酸雨pH值的预测模型

本文用灰色系统理论GM(1,1)建立了大气降水中pH值的预测模型。经三种不同方法检验。对我市1990—1993年大气降水中酸雨pH值进行了预测,结果令人满意。     

生态示范区可持续发展灰色评估系统设计应用

介绍了如何在国家级生态示范区的可持续发展评估中运用灰色系统理论构建定量评估系统模型,并给出了关系型指标表、量纲模型、多元灰色预测模型和发展系数模型以及应用实例.根据该评估系统模型所开发的灰色评估系统由数学模型、计算机软件和硬件组成,可自动完成量纲统一、指标预测、相关分析、综合评估和趋势图表的运算和输出.     

灰色理论及改良方法对我国垃圾产量的预测

为了给城市环境规划提供理论依据,需要对城市生活垃圾产量进行预测,以期揭示其变化规律和发展趋势。本文对三种预测模型进行对比分析研究,并通过灰色关联度分析,选取与垃圾产量最为相关的5个因素,建立了包括多个因素指标的GM(1,1)预测方程的多元线性回归综合模型。该模型考虑了城市生活垃圾产量的主要影响因素,得到的拟合数据比较理想,预测模型和结果也更为合理可信。     

灰色系统方法在城市生活垃圾量预测中的应用

利用灰色关联分析方法分析了影响城市生活垃圾量的因素，建立了生活垃圾量的ＧＭ（１，１）预测模型，预测了未来的城市生活垃圾量。该法具有较高的精度，简便，可行。     

MATLAB在环境评价和规划中的应用

本文简述了MATLAB软件的由来和发展，介绍了其主要功能及优点。主要通过在环境评价与规划中的应用实例，展示其在环境科学研究中的应用潜力。文中的第一个实例是MATLAB在多项水质参数的综合评价中的应用，文中对不同的多项水质参数评价方法进行了比较；另一个实例是MATLAB应用于城市固体废物管理规划，极大地提高了规划的水平和准确性，提高了工作效率。最后文中对于该软件在环境学科研究中的应用潜力和优势展开了讨论。     

径向基函数网络模型在区域生态承载能力综合评价中的应用

径向基函数神经网络以其逼近能力、分类能力和学习速度等方面的优势,正受到越来越多学者的关注.本文尝试用MATLAB径向基函数网络工具进行区域生态承载能力的综合评价,给出了MATLAB6.5环境下径向基函数神经网络的结构、设计、仿真和图形结果的输出方法.作为实例,对盐城滨海湿地区域的生态承载能力进行了综合评价.结果表明,MATLAB径向基函数网络评价方法简单有效,既具有较强的分类功能,又具有较好的排序功能,评价结果可靠、适用性强,具有广阔的应用前景.     

基于VB ActiveX方法的土地复垦信息系统设计——以保安煤矿区为例

从VB、MapX和Matlab的技术结合点入手，发挥两者优势并应用于矿区土地管理信息系统的设计与实现。以矿区土地复垦管理信息系统的开发应用为例，重点介绍了当前VB与MATLAB编程的ActiveX方法。     

基于因子分析的BP神经网络对成都市需水量的预测

在对四川省成都市的水资源进行综合规划与评价的过程中,通过主成分因子分析可知人口、GDP、给排水管道长度等因素对需水量预测有较大影响,如何建立这些因素与需水量之间的数学关系是预测工作的重点。本文将介绍通过MATLAB数学分析软件建立BP神经网络预测模型,并对模型的预测结果进行评价。     

Optimization of membrane-based CO2-removal from natural gas using simple models considering both pressure and temperature effects

Simple models for permeability and selectivity variations of the CO₂/CH₄ system in 6FDA-2,6-DAT membrane have been derived that include both temperature and pressure effects simultaneously in a single equation. The proposed models were used in MATLAB, for a membrane-based CO₂-removal process design for natural gas sweetening. The effects of the following factors on design parameters were examined: feed temperature, feed pressure and permeate pressure. The effect of permeate pressure was found to be very significant in the optimization process. In order to reduce hydrocarbon losses to below 2%, a two-stage membrane process was modeled and simulated in MATLAB, and the extent of desired hydrocarbon recovery was shown to be crucial in the optimization process. It has also been shown that there exist minima for the total required area of the two-stage membrane-based process, and as the CO₂ load increases in the feed, the position of these minima shift to higher values of methane loss.     

Investigation of the effects of battery types and power management algorithms on drive cycle simulation for a range-extended electric vehicle powertrain

Fuel cell (FC) hybrid vehicle power trains are an attractive technology especially for automotive applications because of their higher efficiency and lower emissions compared to conventional vehicles. This study focuses on the design of an FC hybrid power train system and evaluation of its simulations for a given speed profile through two alternative power management algorithms (PMAs). Parameters suitable for a small vehicle were taken into consideration in the mathematical model of the vehicle. The proposed hybrid power train consists of an energy storage system, composed of a 4-kg battery pack (either lithium-ion (Li-ion) battery, nickel metal hydride, or nickel–cadmium) and a direct methanol fuel cell (DMFC) as the range extender. The PMAs basically aim to fulfill the power requirements of the vehicle and decide how to command the power split between the battery and the FC. The model comprising a DMFC, a battery, and PMAs was developed in MATLAB/Simulink environment. The polarization curve of the FC was obtained using a one-dimensional DMFC model. Vehicle power requirements for a drive cycle were calculated using the equations of longitudinal dynamics of vehicle, and the results were integrated into MATLAB/Simulink model. As a result of the simulations, methanol consumption, state of charge of the battery, and power output of the FC were compared for the PMAs. This comparison shows the effect of PMAs on the hybrid vehicle performance for three battery types. The results indicate that the vehicle range could be increased when proper strategy is used as PMA.     

A water network optimization using MATLAB—A case study

The methodology of mass and energy integration is widely applied for reduction of water consumption, which belongs to the area of mass integration, and is also energy integration problem if water is considered an energy source (cooling water and steam). This work presents a study of water-consumption reduction through optimization of the process superstructure. A petroleum refinery water network was analyzed and a solution is proposed to minimize the costs of fresh water and wastewater treatment. Three processes which use water, with three contaminants, were monitored and three potential treatment units are proposed. The procedure was based on relaxation of a non-convex non-linear programming problem into a mixed integer linear programming (MILP). The MILP model was further simplified using heuristic rules and solved by using MATLAB.     

基于灰色关联分析和层次分析法的工业结构生态化调整--以南京市为例

为推进工业结构生态化转型,本文从经济、能耗和环境三方面综合效益出发,以灰色关联分析和层次分析法为工具,对南京市工业结构进行了定量与定性相结合的分析,克服了经济单因子分析的弊端,给出了南京市工业各行业生态化发展序列。为其工业结构的生态化调整提出了建设性意见。定量分析过程中,通过Microsoft Visual C＋＋ 6．0直接调用MATIAB数学库函数。克服了近似算法精确度欠佳的缺陷,提高了分析精度。     

机场飞机噪声的预测研究

本文以机场飞机噪声为研究对象,采用国际民航组织推荐使用的计权等效连续感觉噪声级(LWECPN)为评价量,以广汉机场为例,通过定量分析,利用MATLAB拟合出机场周围各监测点飞机噪声与跑道中心线对数距离的线性方程,然后将该方程用于对未知监测点的LWECPN预测,并与实测数据对比检验其准确度。结果表明,采用该线性拟合预测方法所得到的未知监测点的噪声预测值与实测值较为接近,两者的相对误差保持在1.0%到2.0%之间,预测准确度较好。值得一提的是,该方法操作相对简便,可以达到快速预测机场周边噪声敏感点LWECPN的目的,为今后飞机噪声的预测研究提出一种新的预测方法,具有一定的实际意义。     

Selecting the Best Compatible SVC Type in Power Systems for transient Stability

Considering the increased trend to use renewable energy to meet electrical energy demands, a reliable performance also should be adopted in transmitting the generated power through the stable transmission and subtransmission systems for which nowadays Flexible AC Transmission System (FACTS) controllers are used extensively. Transient stability is one of the most important issues in power system stability analysis. FACTS devices have confirmed their capabilities in various aspects in power networks. In this paper, to improve transient stability of power systems, a shunt connected FACTS devices have been introduced, i.e., Static VAR compensators (SVCs). The SVC has the most diversified branches among FACTS devices. The main aim of this work is to study and analyze the impact of eight branches of SVC on improvement of transient stability and to choose the best of them. Simulations are performed in MATLAB/SIMULINK environment.