数量化方法在试题难度预测中的应用

本文提出了一种试题难度的客观测定方法．该方法不同于传统的试测法和直接评价法，基本上解决了试题难度测量中的主观性、随意性、模糊性问题． 本方法中的基本公式是基于数量化理论Ｉ，借助微机处理大量专家对试题评价结果而得到的．     

A direct method for determining the mass of gases in ICF shell

In the present paper, the defects of dew point method for measuring the mass of gas filled in ICF shells are analyzed. An accurate state equation for gas D2 is deduced from Benedict-Webb-Rubin (BWR) equation and experimental data in planar phase. A direct method to determine gas mass in ICF shells via measuring the temperature and pressure outside the shells and solving the equation of state by numerical method is proposed. It overcomes the theoretical defects of dew point method and the complexities of equipment. In the present method, the state equation can be improved by more accurately measuring P-V-T values of gas D2, so the measuring precision of the mass of gas in the shells can also be improved. The present method is effective for treating mix gases filled in the shells as well. The errors between the computational results and experimental data are very small. Some cases in the filling process are predicted, and the proper temperature and pressure for filling gases effectively are also suggested.     

An improved high precision measuring method for shaft bending deflection

The circular-section columnar parts, such as shaft, rod and pipe etc., are widely used in all kinds of machines. The bending deformation of such parts will seriously affect the assembly precision and working performance of the machines. A high efficiency and precision measuring method for bending deflection is needed. With a classic contact-detection mechanism at low cost composed of a displacement sensor, a lever and a shaft supporting device, a high precision measuring algorithm is proposed and deduced after strict mathematical analysis in this paper, and which is a closed analytic algorithm and will not produce any principle error. The parameters sensitivity auditing is carried out and the result shows the measuring method has high adaptability. Furthermore, the corresponding experimental calibration method of the current measurement technology is provided, and an experimental validation on the bending deformation of a particular shaft is carried out. The result shows in depth the proposed method has high accuracy.     

Measuring magnetic liquid crests by radioscopy

We present a quantitative method, capable of measuring the three‐dimensional shape of a fluid surface. Utilizing the attenuation of x‐rays in magnetic liquids we are able to map amplitude and relief of large wave crests, a regime which is not accessible by the common optical methods. The technique is applied for measuring the static surface deformations of the Rosensweig instability. It will also be useful for measuring the surface profile of the Faraday instability in magnetic liquids, in standard fluids, in liquid metals, or even in granular material.     

熵—证券投资组合风险的一种新的度量方法

本文在研究马科维茨 ( Markowitz)证券投资组合模型的基础上 ,分析了该模型用方差度量风险的缺陷 ,进而提出用熵作为风险的度量方法 ,改进马科维茨 ( Markowitz)证券投资组合模型 ,并建立新的证券投资组合优化模型     

单向S-粗集粗糙性的度量方法

根据单向S-粗集内(外)边界的定义,引入了外边界熵的概念,将外边界熵与知识粒度结合进来,提出了一种新的单向S-粗集粗糙性的度量方法,讨论了这一度量的特性。通过分析和实例可以看出,这一新的度量方法可以用来更合理、更精确地度量单向S-粗集的不确定性。     

我国各地区全要素生产率的测定与比较分析

全要素生产率是衡量经济效益的一项重要指标.本文利用生产要素的影子价格作为权重,提出一种计算全要素生产率的方法.用该方法计算了全国各省（直辖市）的全要素生产率,并对计算结果进行了比较分析.     

A comparative study of the steady state and the transient liquid crystal technique for determining the heat transfer coefficients in a bend

For the investigation of internal and external heat transfer thermochromic liquid crystals (TLC's) have become a very commonly used tool. Today, mainly two different experimental methods with TLC's are in use: The steady state TLC method measuring the wall temperature according to a constant heat flux produced by a heater foil and the transient TLC method measuring the time response of the wall temperature due to a sudden change of the fluid temperature. In the present paper the two different measurement techniques are compared for a very complex 3D flow inside a 180°‐turn of a two‐pass cooling system. From theoretical considerations, the general difference in the heat transfer because of the different wall boundary conditions is shown.     

Vibrations Action of the Trilling Machine MA750 on the Human Operator Hand

The Work includes identifying and analyzing vibrations produced by a trilling machine MA750 within space work. To identify vibration is used a special method, which has not been used so far in identifying vibrations, with the action on the human body. For obtaining a very good identification of the human body vibrations has been used the Moiré projection method. General conditions were applied to human hand operator during working hours on a trilling machine, with different speeds of main shaft. In the paper are presented successively two methods of measuring the vibrations: the Moiré projection method and conventional method of measuring the vibrometer. The results in the booth situation (classical measurements and Moiré projection method) were in the same order of the unit scale, and the optical method named Moiré projection method can be considered a valid method for the human vibrations measurements without touch of the surface. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

均值-叉熵证券投资组合优化模型

在研究马科维茨(Markowitz)证券投资组合模型的基础上,分析了该模型用方差度量风险的缺陷,进而提出用叉熵作为风险的度量方法,建立了均值-叉熵的投资组合优化模型.该模型计算简便,更易被一般投资人所使用.     

Single-axis vibratory gyroscopes

The paper deals with the principles of single-axis vibratory gyroscope operation. A mathematical model for a single-mass vibratory gyroscope and some modes of its operations are considered and relations between measured values (angle of rotation or angular rate) and sensitive mass generalized coordinates are described. Some details for the forced oscillations mode used in measuring of the angular rate and for two modes of natural oscillations used in measuring of the rotational angle and angular rate are described. A new method for identification of anisoelasticity in a single-axis vibratory gyroscope is suggested. __________ Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 11, No. 8, pp. 149–163, 2005.     

The Financial Attractiveness of a Project: A Method of Assessing it

A generalization of the Discounted Cash Flow method of measuring return on investment is shown to provide a well-defined and useful measure for all cash flow series which can be regarded as relating to an investment project. Problems of multiple solutions and of inadmissible implicit assumptions that can arise with the standard DCF method are thus overcome, while the essential features of the method are retained. In a large proportion of cases met in practice the generalized procedure reduces to the standard one. The possibility of a time-dependent cost of capital is included in the analysis.     

超声波测速仪的计算流体力学数值模拟研究

超声波测速仪是一种利用超声波发射接收装置,通过发射接收时间来计算来流速度的一种仪器装置.目前国内许多研究都关注在如何消除测速仪的测量误差上,对于模型结构对测量风场的影响研究较少.为了考察测速仪的测量精度,本研究以模型结构对测量区域风速的影响作为关注的重点,采用计算流体力学方法模拟了从低速到高速的不同来流风速下的绕流流场,计算出位于测速仪中心区域的速度分布和不同截面上的平均速度,以判断测速仪模型结构对中心测量区域风速的影响程度.该研究结果表明在测速探头平面内测量到的速度值,无论在低速和高速时均最为准确.采用计算流体力学数值模拟方法可为今后的测速仪模型设计和改造提供准确的依据.     

基于TOPSIS的区间直觉模糊多属性决策法

对基于区间直觉模糊信息的多属性决策问题进行了研究。给出了区间直觉模糊数之间的距离公式,并定义了区间直觉模糊正、负理想点,进而提出了一种基于TOPSIS的区间直觉模糊多属性决策方法。最后进行了实例分析。     

Determination of the initial stress tensor from deformation of underground opening in excavation process

Applications of Mathematics - A method for the detection of the initial stress tensor is proposed. The method is based on measuring distances between pairs of points located on the wall of...     

Measures of inconsistency and defaults

We introduce a method for measuring inconsistency based on the number of formulas needed for deriving a contradiction. The relationships to previously considered methods based on probability measures are discussed. Those methods are extended to conditional probability and default reasoning.     

跟踪雷达测量误差的统计模型(Ⅰ):模型的建立

本文提出以如下具有慢时变万差的线性回归－自回归混合模型用于描述跟踪雷达测量误差的变化规律，并提出了模型个数的估计方法．数值例子表明，本文提出的模型能较好地拟合跟踪雷达误差数据．     

A method of iterative data refinement and its applications

Iterative data refinement (IDR) is a general procedure for producing a sequence of estimates of the data that would be collected by a measuring device which is idealized to a certain extent, starting from the data that are collected by an actual measuring device. Following a discussion of the fundamentals of IDR, we present a number of previously published procedures which are special cases of it. We concentrate on examples from medical imaging. In particular, we discuss beam hardening correction in x-ray computerized tomography, attenuation correction in emission computerized tomography, and compensation for missing data in reconstruction from projections. We also show that a standard method of numerical mathematics (the parallel chord method) as well as a whole family of constrained iterative restoration algorithms are special cases of IDR. Thus IDR provides a common framework within which a number of originally different looking procedures are presented and discussed. We also present a result of theoretical nature concerning the initial behavior of IDR.     

Determination of arterial wall shear stress

The arteries can remodel their structure and function to adapt themselves to the mechanical environment. In various factors that lead to vascular remodeling, the shear stress on the arterial wall induced by the blood flow is of great importance. However, there are many technique difficulties in measuring the wall shear stress directly at present. In this paper, through analyzing the pulsatile blood flow in arteries, a method has been proposed that can determine the wall shear stress quantitatively by measuring the velocity on the arterial axis, and that provides a necessary means to discuss the influence of arterial wall shear stress on vascular remodeling.