略论数控车削加工典型零件加工方法

数控车床是一种具有高精度、高效率的自动化机床。其具有广泛的加工艺性能,可车削外回转表面、内回转表面、各种特型面及复杂零件等。本文主要阐述了怎样确定典型零件车削加工方案以及在加工过程中加工工序安排、进给路线的确定等方法。     

Estimating the Economic Impact of Event Tourism

Abstract

Tourism has become an important economic sector in many parts of the world, and many regions, states, and local areas have identified expenditures by visitors as a potential source of economic growth. Because visitor spending can contribute to the local economy, many communities seek to enhance tourism and visitor-oriented activities. As a result, estimates of the economic impact of event tourism are of interest to a wide variety of interested parties. Economic impact analyses of sports facilities and other entertainment events have come under increasing criticism in recent years. At the same time, visitors to sports events, festivals, and other visitor-oriented and event related activities can produce very substantial economic impacts for host communities. This article examines key considerations and issues that affect and are critical to reliable estimates of the economic impacts of events and event tourism.     

基于密切值模型的中部六省科技创新能力评价

运用密切值法从科技投入与产出两方面对中部六省的科技创新能力进行评价,根据评价结果针对各省的情况提出建议,为决策者提供决策依据。     

基于人工神经网络的水电工程施工安全评价

为了减小传统施工安全评价方法中主观因素过大对风险评价结果的不利影响,针对水电工程施工安全事故的动态性、随机性和模糊性特点,构建水电工程施工安全评价指标体系。通过引入人工神经网络理论,并运用MATLAB辅助设计评价模型,对水电工程施工安全进行评价。应用实例说明:该评价方法具有较高的准确性和可靠性,对于水电工程施工安全评价具有一定的应用价值。     

论物流企业管理中激励制度的构建

在分析物流企业新生代员工的特点和物流企业激励机制存在问题的基础上,提出完善现代物流企业激励机制的措施和相应的考核方法,为物流企业管理提供一定的参考。     

A decision analytic approach for technology portfolio prioritization: aviation safety applications

A decision analytic approach for evaluating new aviation safety products and technologies is developed and demonstrated to consolidate five existing program assessment metrics to develop a unified metric that simultaneously considers the relative importance and contribution of each. This allows for a meaningful and objective evaluation and comparison of the National Aeronautics and Space Administration (NASA) Aviation Safety Program (AvSP) advanced aeronautical products and technologies. The resulting decision model is referred to as the Composite Program Assessment Score (CPAS). The CPAS includes the five existing metrics; technical development risk, implementation risk, fatal accident rate reduction, safety benefits and cost, and safety risk reduction, which are each defined and quantified by different sources. The CPAS involves the scaling and combination of these individual metrics. In this paper, two alternative combinatorial modeling approaches to calculate the CPAS are presented. The weighted sum model and an additive value theory model are compared and contrasted. The resulting CPAS metrics allow an overall comparison of all 48 of the NASA AvSP products and technologies. Currently CPAS is based on preliminary weight measures from subject matter experts to reflect the relative importance of each metric. Actual case studies of both linear and non‐linear value functions are demonstrated.     

大学计算机基础课教学改革的研究

计算思维的提出,对广大计算机教学工作者具有重要的指导意义。文章探讨在大学计算机基础教学中培养学生计算思维的对策措施。     

石油储量价值评价中价格级差分级模型的设计

从资源所有者的角度看，石油储量价值由该储量的价格级差和成本级差构成。针对石油储量的价值评价工作，分析并确定了影响石油资源价值的价格级差因素及其次因子的构成，进而就这些因子形成了价格级差分级的模型。     

机械加工精度的计算机分析系统

提出了机械加工精度的计算机分析方法。该系统由位移传感器、放大电路、A/ D转换卡、计算机等部分组成。该系统通过位移传感器和 A/ D转换卡自动采集工件尺寸数据 ,传入计算机 ,计算机对测量数据进行处理 ,得出加工误差的分布曲线图、X-R图、合格率、废品率等信息 ,从而使误差分析更迅速、更准确 ,为在线分析提供了可能 ,达到及时调整工艺系统 ,降低废品率 ,提高生产效率的目的。     

Parametric,semiparametric, and nonparametric estimation of characteristic values within mass assessment and hedonic pricing models

Parametric estimators, such as OLS, attain high efficiency for well-specified models. Nonparametric estimators greatly reduce specification error but at the cost of efficiency. Semiparametric estimators compromise between these dual goals of efficiency and specification error. Semiparametric estimators can assume general forms within classes of functional forms. This paper applies OLS, the kernel nonparametric regression estimator, and the semi-parametric estimator of Powell, Stock, and Stoker (1989) to a data set, which should, based on theory and previous empirical work, yield positive coefficients. The semiparametric estimator, on average, displayed the performance most consistent with prior expectations followed by the nonparametric and parametric estimators. In addition, the paper shows how the semiparametric estimator can provide insights into the form of misspecification and suggest data transformations.