Back propagation neural networks and multiple regressions in the case of heteroskedasticity

This paper compares the performance between regression analysis and a clustering based neural network approach when the data deviates from the homoscedasticity assumption of regression. Heteroskedasticity is a problem that arises in linear regression due to the unequal error variances. One of the methods to deal heteroskedasticity in classical regression theory is weighted least-square regression (WLS). In order to deal the problem of heteroskedasticity, backpropagation neural network is applied. In this context, an algorithm is proposed which is based on robust estimates of location and dispersion matrix that helps in preserving the error assumption of the linear regression. Analysis is carried out with appropriate designs using simulated data and the results are presented.     

广西农业剩余劳动力转移状况研究

广西要想在西部率先全面建成小康社会。必须解决好农业剩余劳动力的转移问题。本文使用抽样法测算广西2008年农业剩余劳动力总数,并按照劳动力转移去向进行统计分析,揭示转移中存在的突出性问题和提出对策建议。     

大学生社会文化价值观特征分析

一个民族的文化通常有其系统性与适用的价值观,在当今中西文化交融的时代背景下,作为未来栋梁的大学生选择何种价值观体系,一直受到学术界的普遍关注。借鉴相关价值观研究理论,通过因子分析的方法,归纳出大学生的7个价值观类型,并揭示出大学生社会文化价值观的主要特征,即儒家思想中的进取精神得到了大学生的普遍认同,而极端功利与利己主义受到大学生的强烈排斥,大学生的"自我意识"呈现出不统一的特点,实用主义观念在大学生中广泛存在,传统价值观中的"节俭观"和"宿命论"在大学生中受到了严峻的挑战。     

对耕地利用率影响因素及影响效应的统计分析

耕地承包农户的户主年龄、家庭非农收入、土地转让行为选择、农户择业意愿、耕地条件与环境等因素与耕地利用率之间存在显著相关。对此,政府首先必须加强对农民的重农教育,增强农民珍爱耕地的自觉性;其次,应创新耕地管理制度,引导土地合理流转;其三,推进农村土地流转规范,提升耕地资产价值效能;其四,加大支农惠农政策力度,提高农业比较收益;其五,扩大对农村投入,改善农村农业基础设施建设。     

农村留守儿童家庭教养方式的社会学分析

通过对农村"留守儿童"家庭教养方式的现状进行描述和归纳,分析产生不同类型的家庭教养方式的原因,以期引起社会各界对留守儿童群体的关注,更好地指导农村"留守儿童"的家庭教养方式,提高家庭教育质量,促进儿童的健康成长。     

基于因子分析的产学研合作教育影响因素研究

本文通过构建产学研合作教育影响因素的指标体系,运用因子分析法导出其中的主要影响因素,通过多元回归分析,进一步厘清各因子的影响程度,提出促进产学研合作教育人才培养机制的对策建议。     

STOCHASTIC COST-VOLUME-PROFIT ANALYSIS IN A COMPETITIVE OLIGOPOLY

Previous stochastic cost-volume-profit (CVP) models have assumed that the firm was operating under either perfect competition or monopolistic conditions. This paper presents a stochastic CVP model applicable to oligopolistic competition. Each firm is assumed to maximize a linear function of the expected value and the standard deviation of its random profits. The result is a game-theoretic model that is solved using the concept of a Nash equilibrium. The results of the model are used to examine a firm's competitive strength. The model can be easily modified to accommodate a measure of risk based on the capital asset pricing theory.     

MODELING THE ALLOCATION OF GRADUATE STUDENT FINANCIAL AID

Universities have always competed with one another for the relatively small number of highly qualified students interested in graduate education. This competition has been intensified recently by adverse demographic trends. This paper is concerned with the use of financial aid awards as a means of competition and with allocation of awards so that enrollments are maximized while satisfying academic standards and budget constraints. It also considers the randomness of actual aid disbursements and develops models of incremental aid allocation that increase enrollments but are within tolerance levels for budget overruns.     

STOCHASTIC COST-VOLUME-PROFIT ANALYSIS WITH A LINEAR DEMAND FUNCTION

In this paper we incorporate a linear demand function to model the price-volume causal relationship into stochastic cost-volume-profit (CVP) analysis. We assume that the objective function is to maximize expected profit; other objective functions are also discussed and compared. A linear stochastic model follows from which probabilistic statements can be easily obtained if the random variables are assumed to be multivariate normal. The basic framework is shown to be a special case of project value maximization where project value is the cash flow of the project discounted for time and risk according to the capital asset pricing model. Moreover, an intertemporal extension that considers inventory is developed. In summary, a new approach to stochastic CVP analysis that incorporates the management decision process in an uncertain environment is developed.     

转型经济下民营企业家个体特质、情境对公司创业的驱动机制 ——基于QCA的探索性研究

在中国经济转型的大市场环境下,企业如何将公司创业的意愿成功付诸于创业行动,是学术界广泛讨论的话题。文章利用全国私营企业调查问卷表数据,以102家私营企业作为案例样本,通过模糊集定性比较分析(QCA)方法将企业家个体特质与情境两个层面整合,同时从这两个层面进一步细分,去探讨组态效应对公司创业的多重并发影响机制。经过数据分析可以获知,企业家的社群式身份是高公司创业活跃度的必要条件,且导致高公司创业活跃度有四条组态(路径);导致非高公司创业活跃度的有一条组态(路径),两者之间存在非对称关系。