用矿井通风仿真系统(MVSS)确定通风系统优化改造方案

论述了矿井通风仿真系统 (MVSS)的功能 ,用MVSS仿真模拟增加或减少风路对周围其他风路的影响 ,仿真模拟拆除或增加机站对周围通风系统的影响 ,并以金川矿井 115 0水平为例 ,阐明了用MVSS确定通风系统优化改造方案的方法 ,对通风系统现状分析、通风网络优化、通风系统的设计提供了科学的依据和实用方法。     

OPTIMIZATION OF THE HYDROMETRIC NETWORK OPERATION BY A HEURISTIC TRAVELING SALESMAN ALGORITHM1

ABSTRACT: The problem of determining the optimal route to operate a network of hydrometric gauges within a given area is formulated and solved by an original heuristic traveling salesman algorithm. The algorithm used for solving the problem takes into account the variation of station service time, the eight-hour maximum working day, existence of more than one home base, and the budget constraint. The traveling salesman algorithm is used to solve the optima! assignment problem within a one-day time limit, locating a starting base, stations to visit, and the closest home base. The ending base for the previous day becomes the starting base for the next day, and the assignment procedure is repeated. The computation proceeds from day to day, until all the stations in the considered region are serviced. The solution obtained presents the optimal route to operate a network of hydrometric gauges. The optimization procedure has been applied to the Dauphin hydrometric field area in Manitoba.     

THE OPTIMAL STEADY-STATE IN GROUNDWATER MANAGEMENT1

Groundwater use is likely to be inefficient in the absence of regulation and hence there is substantial interest in optimal groundwater withdrawals over time. Under an optimal regime withdrawals, pumping lifts, and profits converge to steady-state levels. In this paper we show that optimal steady-state lifts, withdrawals, and marginal user costs can be readily calculated for multi-cell models of confined aquifers. Applications to the design of economically efficient groundwater management policies are discussed, comparisons to previous work and to the safe yield concept are made, and an illustrative example is given.     

Housing areas — factors that need to be considered in the site layout and design process

The lack of any particular character in much new low‐rise housing is seen as resulting in the lack of attention paid to the detailing of space between buildings. The landscape architect's role in overcoming “placelessness” is considered, and the information needs of designers is discussed. The paper also offers some notes for the designer on user needs.     

基于Matlab优化工具箱的煤巷顶板锚杆支护结构可靠性分析

针对煤巷围岩力学参数中有许多为随机变量的特征,根据围岩稳定性极限状态方程,应用工程结构可靠性理论,分析煤巷顶板锚杆支护结构的可靠性,建立基于Matlab优化工具箱的可靠度计算模型。该法编程简单,计算速度快,精度高,程序通用性强,是一种计算煤巷锚杆支护结构可靠度的有效方法,并且分析该法计算结构可靠度的适用条件,建立了巷道顶板支护参数与可靠度的关系曲线,为煤巷锚杆支护参数设计和优化提供了科学依据。     

我国蔬菜物流链的现状及其优化措施

阐述了蔬菜物流链的内涵及其特征，给出了蔬菜物流链的结构模型，分析了我国蔬菜物流链的主要问题，提出了物流链优化的目标及其措施。     

经济快速发展时期土地利用规划方案研究——以芜湖市为例

在经济快速发展的情况下,土地资源的合理有效利用成为土地利用规划的重点,规划中弹性方案的设计使土地供给需求紧张的局势得到相对缓解。以芜湖市土地利用规划的弹性方案设计为例,以期为土地利用规划决策者提供参考。     

基于灰色系统理论的安全投资方向优化分析

安全投资方向准确与否直接关系安全经济效益的高低。笔者依据安全工作的专业类型将安全投资划分为安全设施投资、工业卫生设施投资、辅助设施投资、安全宣传教育投资、劳动保护投资和事故处理及修复投资6个方向,选用灰色关联分析方法排序比较各方向安全投资与安全产出之间的关联度,以确定各安全投资方向的重要程度,并据此优化安全投资方向。从案例实证检验的结果表明,该方法准确度高,弥补了其他系统分析方法的不足;且可操行性强,方便、简单、实用。     

滇西北地区特色经济的发展与产业结构优化研究

特色经济是发挥地区资源优势的主要途径,产业结构优化是区域经济稳定发展的保证。通过分析滇西北地区产业结构现状和发展特色经济的优势条件以及存在的问题,分析了特色经济的发展与产业结构优化之间的互动关系,进而提出发展特色经济和提升产业结构的策略。     

Soil Moisture Data Assimilation Using Support Vector Machines and Ensemble Kalman Filter1

Abstract: A hybrid data assimilation (DA) methodology that combines two state‐of‐the‐art techniques, support vector machines (SVMs) and ensemble Kalman filter (EnKF), is applied for soil moisture DA in this work. The SVM methodology provides a statistically sound and robust approach to solving the inverse problem, and thus to building statistical models. EnKF is an extension of the Kalman Filter (KF), a well‐known tool in prediction updating. In the present research, ground measurements were used to build a SVM‐type soil moisture predictor. Subsequent observations and their statistics were assimilated to update predictions from the SVM model by coupling it with EnKF. In this way, both model predictions and ground data, as well as their statistics, are fused thus minimizing the prediction error and making the predictions and observations statistically consistent. The results are shown for two approaches; one in which update is done at every time step and the other which assumes that data is only available at alternate time steps (in window of 10 time steps) and hence update is performed at those occasions. The SVM‐EnKF coupling is shown to improve soil moisture forecasts in an example using data from the Soil Climate Analysis Network site at Ames, Iowa.