An Investigation into the Decision Rules of Capital Investment Using Simulation

The paper explores the effectiveness of the major decision rules commonly applied to the selection of investment alternatives. The rules are applied to a continual stream of simulated investments, as they arise period by period throughout the planning horizon. Thus the dynamics of investing now rather than later, with capital rationing, are taken into account. The practitioners' preference for the payback period is examined for a typical series of simulated investments, and the returns are compared against the returns of the more academically acceptable discounting decision rules. Particular attention is devoted to the benefits of each of the decision rules with reference to both risk and average returns.     

An Experimental Investigation of a Nonlinear Mathieu Equation

A study of the equation , using an electronic model, provides a qualitative insight into thenature of its simplest periodic solutions and leads to simpleanalytical results in quantitative agreement with the experimentalobservations. A circuit diagram is given, with practical detailsand an analysis of its operation.     

Experimental Investigation into the Fatigue Damage Performance of a GRP Mortar Pipe Culvert

Mechanics of Composite Materials - The fatigue damage evolution in glass-fiber-reinforced (GRP) mortar pipes under cyclic loading were investigated. Based on the results of fatigue tests, a...     

Handling the valuation of the predicates in a fuzzy model

Given a fuzzy model, and therefore a graded valuation of the predicates, several handlings of such a valuation are possible. For example, we can change the set of truth values, modify the scale, cut the predicates, and identify truth values. In this exploratory paper we analyze some of the properties preserved under these handlings. To do this we refer to an approach to fuzzy semantics in which the valuation structures can vary freely inside a given type.     

Asymptotic Behavior of the Solution to a Model System in Linearly Viscous Materials

In this paper, we investigate the asymptotic behavior of solution to a model system in linearly viscous materials with temperature-dependent viscosity.     

An Investigation of a Pair of Integral Equations for the Biharmonic Problem

The paper contains an elementary investigation of the questionof uniqueness of a pair of integral equations connected withthe plane biharmonic problem. It is shown that for two particularexceptional geometries of the boundary curve the pair of integralequations does not have a unique solution. This defect can beremoved by adding two supplementary integral conditions whichthe solution of the integral equations must satisfy. As an illustrationthe integral equations are solved numerically with and withoutthese extra conditions.     

An International Project for the Development of Data Handling Skills of Teachers and Pupils

In this paper we provide an overview of the international CensusAtSchool project, designed, written and implemented first in the UK from October 2000 - April 2001 for pupils aged 7 -16 in primary and secondary schools. It has been adapted for similar aged school children in South Africa and Australia and was implemented in those countries in July and October 2001, respectively. We present our motivation, aims and objectives for carrying out such a project and show some results of analysis from the returns we have received from all three countries. Key outputs from the project include: worksheets that are suitable for enhancing data handling skills of pupils; a training course that wraps information and communications technology with data handling skills that is suitable to enhance the professional development of teachers; a raised awareness amongst pupils and teachers of the need to properly collect, present and analyze primary data; a contribution to improving the statistical numeracy and thinking skills of both teachers and pupils.     

对称相交圆柱的研究

给出了四个圆柱沿正四面体对称轴方向,六个圆柱沿正方体面对角线方向,六个圆柱沿正十二面体面心连线方向,它们公共相交部分的顶点坐标,表面积和体积.利用数学软件,绘出了它们的三维图形.     

Investigation of a powerful analytical method into natural convection boundary layer flow

The natural convection boundary layer flow modeled by a system of nonlinear differential equations is considered. By means of similarity transformation, the non-linear partial differential equations are reduced to a system of two coupled ordinary differential equations. The series solutions of coupled system of equations are constructed for velocity and temperature using homotopy analysis method (HAM). Convergence of the obtained series solution is discussed. Finally some figures are illustrated to show the accuracy of the applied method and assessment of various prandtl numbers on the temperature and the velocity is undertaken.     

Investigation of the transition to instability of the water boiling front during injection into a geothermal reservoir

Theoretical and Mathematical Physics - We discuss the stability problem for a boiling front moving at a constant speed in a porous permeable geothermal reservoir. We study the dispersion equation...     

An algorithm for the incomplete decomposition of a rational function into partial fractions

Zusammenfassung Es wird ein Algorithmus zur unvollständigen Zerlegung einer rationalen Funktion in Partialbrüche angegeben, mit dem alle auftretenden Sonderfälle in einheitlicher und ökonomischer Weise behandelt werden können. Der zu einem quadratischen Nennerfaktor einer reellen rationalen Funktion gehörige Partialbruch kann ohne Kenntnis der Nullstellen und ohne Koeffizientenvergleich in reeller Arithmetik berechnet werden.     

An Empirical Investigation of the Adaptive-Filtering Learning Factor

Acceptance of the adaptive-filtering parameter-estimation process has been mixed. Much of the variability between studies may result from the particular learning factor selected and may be further affected by the type of standardization used. The author presents a modification of the Makridakis and Wheelwright adaptive-filtering algorithm. This modified algorithm provides superior performance and simplifies the selection of the learning factor when used with simple autoregressive processes.     

基于随机Petri网的航空货运出港系统分析

航空货运出港作业是影响航空货运速度的重要环节。本文根据航空货运出港流程建立了出港系统的随机Petri网模型(SPN)和同构的马尔柯夫链(MC)。以国内某枢纽机场航空货站为例,计算了MC的稳定状态概率,分析了系统的运作效率和延时时间,并对提高航空货运出港系统运行效率提出了建议。     

一种求解救灾物资运输问题的改进解法

本文通过对B运输问题建立数学模型,提出了一种求解B运输问题的改进解法。改进解法首先通过最小元素法求出初始解,然后进行变量闭回路法调整,直到求出最优解,并给出了一个计算实例证明了解法的有效性。文章还对改进解法和另外两种现有的算法进行了综合的分析,由于改进解法计算过程中采用的变量闭回路法省略了求检验数的环节,使得新算法比两种现有的算法更简便。