矿井通风三维可视化系统及优化

系统建立了三维仿真框架,建立了三维空间属性模型和非空间属性模型,分别对空间数据和非空间数据进行储存和管理。并建立了Hardy-Cross迭代模型和离散反馈型神经网络模型优化通风网络模型。并以C#语言来实现系统的功能。     

路基稳定性数值分析

本文通过对常见的路基稳定性分析案例进行强度折减法的数值分析,为进一步研究这一方法在路基稳定性分析中的应用奠定基础。     

基于熵权TOPSIS法的在线旅游企业竞争力实证分析

在线旅游企业竞争力分析顺应了旅游企业发展的客观需要、顺应了互联网与旅游相结合的时代要求、顺应了当前国家大力支持旅游业发展的整体趋势。运用熵权TOPSIS法对在线旅游企业的竞争力进行实证分析，更具客观性、系统性、科学性、权威性。提升在线旅游企业的竞争力需要综合考虑企业的规模、企业的经营业绩、企业的服务能力以及企业的创新能力。     

On estimating long-run effects in models with lagged dependent variables

A common procedure in economics is to estimate long-run effects from models with lagged dependent variables. For example, macro panel studies frequently are concerned with estimating the long-run impacts of fiscal policy, international aid, or foreign investment.Our analysis points out the hazards of this practice. We use Monte Carlo experiments to demonstrate that estimating long-run impacts from dynamic models produces unreliable results.Biases can be substantial, sample ranges very wide, and hypothesis tests can be rendered useless in realistic data environments. There are three reasons for this poor performance. First, OLS estimates of the coefficient of a lagged dependent variable are downwardly biased in finite samples. Second, small biases in the estimate of the lagged, dependent variable coefficient are magnified in the calculation of long-run effects. And third, and perhaps most importantly, the statistical distribution associated with estimates of the LRP is complicated, heavy-tailed, and difficult to use for hypothesis testing. While many of the underlying problems have been long-known in the literature, the continued widespread use of the associated empirical procedures suggests that researchers are unaware of the extent and severity of the estimation problems. This study aims to illustrate their practical importance for applied research.     

数控车床加工实训中的故障分析

本文通过分析学生在数控车床实训时易产生的故障和操作失误,阐述了故障发生的原因、避免或排除的对策,以切实提高学生的数控加工能力。     

因素分析法在施工统计分析中的应用

施工统计分析中因素分析法的应用,指的是对施工全过程出现的各种情况,运用统计方法进行分析,从中找出其中存在的规律,进而提出相应的解决措施。本文对于施工统计分析中因素分析法进行了剖析,对于其中存在的问题提出了相应的解决措施。     

浅谈行动导向教学法在五年制高职教育中的应用

五年制高职教育实现了中等职业教育与高等职业教育的有机衔接,是我国高等职业教育的重要形式,其教育目标的实现要依靠先进的教学理念和有效的教学方法。其中,行动导向教学法是培养学生综合能力,全面推荐素质教育的有效模式之一。本文将从应用条件、应用导向以及具体教学方法三个方面浅析行动导向教学法在五年制高职教育中的实践,以求在丰富多彩的教学过程中,全面提升学生职业素养,为地方经济建设输送专业技术型人才。     

A general endogenous grid method for multi-dimensional models with non-convexities and constraints

The endogenous grid method (EGM) significantly speeds up the solution of stochastic dynamic programming problems by simplifying or completely eliminating root-finding. We propose a general and parsimonious EGM extended to handle (1) multiple continuous states and choices, (2) multiple occasionally binding constraints, and (3) non-convexities such as discrete choices. Our method enjoys the speed gains of the original one-dimensional EGM, while avoiding expensive interpolation on multi-dimensional irregular endogenous grids. We explicitly define a broad class of models for which our solution method is applicable, and illustrate its speed and accuracy using a consumption–saving model with both liquid assets and illiquid pension assets and a discrete retirement choice.     

白音查干矿井涌水量预计

矿井涌水量计算是矿床水文地质勘查中一项重要而复杂的工作,也是矿床水文地质勘查中的根本任务之一。运用大井法和廊道法对首采区、首采工作面和开切眼涌水量进行了预计,认为大井法计算的涌水量成果较为可靠,矿井最大涌水量为296.80m3/h,为今后的矿井安全生产提供了理论依据。     

浅谈发出存货计价方法的选择

对存货计价问题的产生进行说明,详细介绍了5种发出存货计价方法,并且通过它们之间的比较,重点阐述了企业如何根据自己选择恰当的存货计价方法。这样,选择比较合理的发出存货计价方法,可以有效达到企业管理的目标。