Mathematic education in a cultural setting

The paper develops some proposals for curriculum development in mathematics based on an analysis of the intercultural transmission of mathematical knowledge. By introducing a concept of culture which calls for an analysis of individual and social behaviours, we are lead to recognize ‘ethnomathematics’ as a form of structured knowledge and to recognize ‘matheracy’ as a characteristic behaviour of human beings. Upon these two concepts, we introduce a theoretical framework for curriculum development in mathematics.

Curricular space is conceptualized as a three‐dimensional space with components, contents, methods and objectives considered solidarily. This relies upon an epistemology of action, based on an integration of episteme, techne and praxis. This allows for an approach in which theory and practice are in a dialectical relationship. Special reference is made to the problems of mathematical education for culturally differentiated groups, and in particular to the situation in third‐world countries.     

Perceptions of the software skills of graduates by employers in the financial services industry

Software, particularly spreadsheet software, is ubiquitous in the financial services workplace. Yet little is known about the extent to which universities should, and do, prepare graduates for this aspect of the modern workplace. We have investigated this issue through a survey of financial services employers of graduates, the results of which are reported in this paper, as well as surveys of university graduates and academics, reported previously. Financial services employers rate software skills as important, would like their employees to be more highly skilled in the use of such software, and tend to prefer ‘on-the-job’ training rather than university training for statistical, database and specialized actuarial/financial software. There is a perception among graduates that employers do not provide adequate formal workplace training in the use of technical software.     

基于M~x/G/1排队模型的信息系统软件失效风险分析方法研究

研究首先对信息系统软件节点进行数学建模,然后根据M^x/G/1排队模型及分布函数,针对信息系统软件的可靠性,给出了由威胁利用软件脆弱性所导致的信息系统节点失效,以及由此所带来的损失风险计算模型,并以银行的柜面业务系统所安装的Windows和Linux操作系统为例,给出了详细的计算过程.风险分析模型突破了目前沿用的经典六因素模型,将系统可靠性的定量分析方法引入其中,从而有效的避免了风险分析方法中对主观因素的依赖.     

基于SARIMA模型的居民消费价格指数预测分析

本文基于SARIMA模型对我国1990—2010年的居民消费价格指数月度数据进行预测分析。利用Eviews6.0对统计数据的变化趋势及季节性进行验证,结果表明该模型合理、有效,预测值与实际值的估计误差控制的很好。     

Extensible Statistical Software: On a Voyage to Oberon

Abstract

Recent changes in software technology have opened new possibilities for statistical computing. Conditions for creating efficient and reliable extensible systems have been largely improved by programming languages and systems that provide dynamic loading and type-safety across module boundaries, even at run time. We introduce Voyager, an extensible data analysis system based on Oberon, which tries to exploit some of these possibilities.     

Detecting Clusters and Nonlinearity in Three-Dimensional Dynamic Graphs

Three-dimensional dynamic scatterplots can reveal certain features of data that cannot be apprehended in marginal two-dimensional displays. Using graduate students as subjects, we sought to establish whether the detection of clusters and nonlinearity in 3-D plots varies by easily characterized properties of the data and the design of the display. We found that the probability of detection of clusters increased smoothly with cluster separation, and that, at a fixed level of separation, “diagonally” displaced clusters were easier to detect than “horizontally” displaced clusters. Cluster detection appeared to be affected to a smaller extent by the design of the display. Three further experiments addressed the detection of nonlinearity in 3-D dynamic scatterplots. Most subjects were able to respond in a reasonable manner to properties of the data, so that the probability of detection of nonlinearity increased with its level, particularly when the signal was strong. As in the experiment on cluster detection, subjects' performance was also affected, though to a lesser extent, by characteristics of the displays; for example, spinning the display horizontally in the regression plane was particularly effective. We discuss the implications of these results for the design of statistical software incorporating dynamic 3-D scatterplots.     

Modelling and well-posed analysis for software system with rejuvenation

Software rejuvenation, as an effective policy to enhance the performance of software system, has been discussed broadly with the hypothesis that the software system being well posed. A system being well posed means that the dynamical solution not only exists and is unique but also is stable, which means the dynamical solution converges to steady solution as time tends to infinity. To enrich the theory basis of the software system, and to simulate the dynamical solution which is also an instantaneous availability of the software system with rejuvenation, this article models the behaviour of software system by a group of ordinary and partial equations. With the theory of strong continuous semigroup, this article proves that the system is well posed. As a result, the expression and simulation of instantaneous availability of the system is presented.     

Improved Effort and Cost Estimation Model Using Artificial Neural Networks and Taguchi Method with Different Activation Functions

Software estimation involves meeting a huge number of different requirements, such as resource allocation, cost estimation, effort estimation, time estimation, and the changing demands of software product customers. Numerous estimation models try to solve these problems. In our experiment, a clustering method of input values to mitigate the heterogeneous nature of selected projects was used. Additionally, homogeneity of the data was achieved with the fuzzification method, and we proposed two different activation functions inside a hidden layer, during the construction of artificial neural networks (ANNs). In this research, we present an experiment that uses two different architectures of ANNs, based on Taguchi’s orthogonal vector plans, to satisfy the set conditions, with additional methods and criteria for validation of the proposed model, in this approach. The aim of this paper is the comparative analysis of the obtained results of mean magnitude relative error (MMRE) values. At the same time, our goal is also to find a relatively simple architecture that minimizes the error value while covering a wide range of different software projects. For this purpose, six different datasets are divided into four chosen clusters. The obtained results show that the estimation of diverse projects by dividing them into clusters can contribute to an efficient, reliable, and accurate software product assessment. The contribution of this paper is in the discovered solution that enables the execution of a small number of iterations, which reduces the execution time and achieves the minimum error.     

EXCEL在物理实验数据处理中的应用研究

介绍了用Excel软件对实验数据进行计算平均值、标准偏差、拟合方程的方法.通过举例介绍了Excel软件在作图,直线方程拟合方面的应用技巧.实践表明:用Excel软件处理实验数据具有快捷、直观、简易的优点,掌握Excel软件能够有效的提高学生对实验数据处理的能力.