端面圆跳动与线面垂直度的标注辨析

着重对端面圆跳动，线面垂直度两项形位公差从定义，零件用途，测量和加工等方面进行了对比分析，从而较好地解决了对两者进行合理标注的问题。     

机械零件精度设计中形位公差的合理选择

形位公差项目的合理选择与标注是在设计、制造及质量控制等方面优化机械产品质量的前提保障。本文详细分析形位公差的关系,结合实例提出确定形位公差时公差项目、基准、公差数值的选择及在图纸上进行合理标注的方法。     

波纹管及波纹管组合件形位公差的工艺技术综述

针对波纹管类弹性敏感元件中各类形位公差问题,文章从影响形位公差的原因入手,归纳了不同材料、结构波纹管及组合件的相关形位公差要求的工艺技术保证措施,并通过产品实例列举展示了各工艺保证措施在实践中的应用,旨在为波纹管类弹性敏感元件在保证形位公差工艺技术研究中提供新的思路和方法。     

端面垂直度、轴向圆跳动及轴向全跳动关系探讨

几何公差分为形状公差、方向公差、位置公差、跳动公差四种类型，相互间具有一定的关系，文章以端面垂直度公差、轴向圆跳动公差、轴向全跳动公差为例，在明确各公差项目含义的基础上，从公差带及应用上论述了相互间的关系，对更好的理解几何公差具有引导的作用。     

要素理想形状的确定

标注、阅读形位公差代号的关键在于明确被测要素的理想形状.众所周知,被测要素的理想形状取决于形位公差代号中的几何特征符号和公差带形状符号.但是,几何特征符号和公差带形状符号都只能表示有限的内容,除单一要素形状公差而外,要唯一确定形位公差所涉及的各个要素的理想形状,还必须有一些人为的约定.     

要素理想形状的确定

标注、阅读形位公差代号的关键在于明确被测要素的理想形状.众所周知,被测要素的理想形状取决于形位公差代号中的几何特征符号和公差带形状符号.但是,几何特征符号和公差带形状符号都只能表示有限的内容,除单一要素形状公差而外,要唯一确定形位公差所涉及的各个要素的理想形状,还必须有一些人为的约定.……     

零件设计中形位公差项目的选择

在进行零件设计时,正确选择形位公差项目及其公差值的确定是一项很慎重的工作,既要根据零件的使用性能和互换性要求,又要考虑生产率和成本的高低。本文仅对形位公差项目的选择进行初步的探讨。     

新形位公差标准应用简介(续)

一、最大实体要求最大实体要求是指被测要素的实际轮廓应遵守其最大实体实效边界，当其实际尺寸偏离最大实体尺寸时，允许其形位误差值超出在最大实体状态下给出的公差值的一种要求。即允许形位公差值增大。它是允许尺寸公差补偿给形位公差的一种要求。最大实体要求用符号...     

浅析“公差原则”在形位公差新,旧标准中之差异

分析了公差原则在形位公差新、旧国标中的不同之处。     

多层次三维工艺模型的形位公差推理方法研究

基于模型的定义已成为机加工艺设计的研究热点,为解决三维环境下模型上制造信息的表达和形位公差主动推理的问题,本文提出了多层公差表示模型。利用加权有向图表达加工功能表面、基准、尺寸和公差。利用多色集合理论实现形位公差推理,最后用实例验证了该方法的有效性。     

Measuring a contract's breadth: A text analysis

We use a computational linguistic algorithm to measure the topics covered in teacher contracts. Topic modeling metrics are used to assess a contract's expansiveness. Our topic, diversity measurement, is then related to the prevalence of support staff. If more specialized services are provided, then contracts should be broader as they cover more employment relationships. We confirm a strong, statistically significant relationship and, thus, have a valid measurement of contract breadth.     

Measuring Scale Efficiency from a Translog Production Function

In parametric analysis based on a frontier production function, usually the scale elasticity rather than scale efficiency level is reported. In this paper we show how one can use an estimated translog production function to obtain output- and input-oriented measures of scale efficiency at an observed input bundle. We also show how the estimated model can be used to determine the optimal quantity of labor input for an exogenously fixed quantity of capital.     

Measuring innovation and innovativeness: a data-mining approach

Despite substantial advances over the past decades, measuring innovation and innovativeness remains a challenge for both academic researchers and management practitioners. To address several key concerns with current indicators—such as their specialization and consequent one-sidedness, their frequent lack of theoretical foundations, and the fact that they may not really foster creativity and invention—this paper introduces some new metrics via one data-mining approach—formal concept analysis—which is increasingly used to represent and treat knowledge. This approach can adapt to particular needs and goals, incorporate various kinds of information (qualitative or quantitative) from different sources, and cope with several types of innovations. It also uncovers a logical route to novelty, which might enhance the generation of ideas and is used here to support the measurement of innovativeness.

     

Measuring the development impact of a proposed transportation system

This paper introduces a methodology of measuring economic development impact incident to a proposed transportation system and provides an empirical result of such estimation. As the methodology, a Multi-Regional Variable Input-Output (MRVIO) model is introduced, and as a case study, the proposed Coosa River Navigation project is discussed. The Coosa River project when completed is expected to reduce the cost of shipping commodities from origin to destination, and such reduction in shipping costs will stimulate the economy of the Coosa River Corridor, the Gulf-Coast Region, the Rest of Alabama, and the Remainder of the U.S. The empirical measurement was done in terms of industrial outputs, personal income, and employment of each of 31 industries in four regions in decennial years starting in 1990 and ending in 2039     

Measuring scale efficiency from a parametric hyperbolic distance function

This paper shows how scale efficiency can be measured from an arbitrary parametric hyperbolic distance function with multiple outputs and multiple inputs. It extends the methods introduced by Ray (J Product Anal 11:183–194, 1998), and Balk (J Product Anal 15:159–183, 2001) and Ray (2003) that measure scale efficiency from a single-output multi-input distance function and from a multi-output and multi-input distance function, respectively. The method developed in the present paper is different from Ray’s and Balk’s in that it allows for simultaneous contraction of inputs and expansion of outputs. Theorems applicable to an arbitrary parametric hyperbolic distance function are introduced first, and then their uses in measuring scale efficiency are illustrated with the translog functional form.     

Measuring the welfare costs of inflation in a life-cycle model

In a neoclassical growth model with life-cycle households in which money is held to satisfy a cash-in-advance constraint, the optimal steady state inflation rate is absurdly high: in excess of 20%. Lump-sum, age-independent money injections twist and flatten the lifetime profile of utility, making this profile look more like the one that would be chosen by a planner. The cost of monetary finance of lump-sum payments is the distortion introduced to the labor-leisure choice.     

Measuring heterogeneity in hospital productivity: a quantile regression approach

Journal of Productivity Analysis - This paper focuses on acute-care local public hospitals in Japan and evaluates differences in hospital technology, as reflected in the productivity of labor...     

测土施肥试验

应用测土施肥技术根据不同田块施用配方肥可以提高肥料利用率节省肥料、促进水稻生长、提高水稻秧苗素质,改善水稻品质,增加水稻产量,增加效益。进一步解决农民施肥不合理,盲目施肥等情况,特做此试验对配方肥进行验证。