ON TWO APPROACHES TO COHERENT RISK CONTRIBUTION

We compare two approaches to the coherent risk contribution: the directional risk contribution is defined as where ρ is a coherent risk measure; the linear risk contribution ρ^l(X; Y) is defined through a set of axioms, one of which is the linearity in X . The linear risk contribution exists and is unique for any ρ from the Weighted V@R class. We provide the representation for both risk contributions in the general setting as well as in some examples, including the MINV@R risk measure defined as where X₁, … , X_N are independent copies of X .     

Accommodating spatial correlation across choice alternatives in discrete choice models: an application to modeling residential location choice behavior

This paper presents a modeling methodology capable of accounting for spatial correlation across choice alternatives in discrete choice modeling applications. Many location choice (e.g., residential location, workplace location, destination location) modeling contexts involve choice sets where alternatives are spatially correlated with one another due to unobserved factors. In the presence of such spatial correlation, traditional discrete choice modeling methods that are often based on the assumption of independence among choice alternatives are not appropriate. In this paper, a Generalized Spatially Correlated Logit (GSCL) model that allows one to represent the degree of spatial correlation as a function of a multi-dimensional vector of attributes characterizing each pair of location choice alternatives is formulated and presented. The formulation of the GSCL model allows one to accommodate alternative correlation mechanisms rather than pre-imposing restrictive correlation assumptions on the location choice alternatives. The model is applied to the analysis of residential location choice behavior using a sample of households drawn from the 2000 San Francisco Bay Area Travel Survey (BATS) data set. Model estimation results obtained from the GSCL are compared against those obtained using the standard multinomial logit (MNL) model and the spatially correlated logit (SCL) model where only correlations across neighboring (or adjacent) alternatives are accommodated. Model findings suggest that there is significant spatial correlation across alternatives that do not share a common boundary, and that the GSCL offers the ability to more accurately capture spatial location choice behavior.     

基于行政记录的广西人口数目估计

广西普查年或非普查年的人口数目通过统计调查方法获得,这种方法的缺陷是成本高、时间长。这就需要我们探索其他的人口数目来源渠道。行政记录是一种比较好的来源。使用行政记录资料估计人口数目的方法有人口统计分析模型和线性回归模型。人口统计分析模型是一种利用人口出生、死亡、迁移及其他资料估计人口数目的宏观统计方法。它的优点是节约成本,缺点是所依据的数据资料有时残缺不全,结果影响人口数目估计的精度。线性回归模型利用行政记录资料和人口统计调查资料的相关性对人口数目进行估计。文章利用广西户籍人口变动资料,使用这两个模型估计广西2010年人口数目,并且对估计的结果进行了评价。     

风险与收益权衡的期权组合策略

本文对Papahristodoulou的风险中性模型进行了推广,提出了在希腊字母上具有可控制风险界的线性规划模型来确定最佳期权组合策略。在此模型中,风险界可以由投资者根据自己的个性和对市场风险的接受能力选择,然后通过风险与收益的权衡来进行调整。最后,应用本文的模型对爱立信看涨权和看跌权的组合策略进行了分析计算。     

浅谈培养和提高学生数学建模能力的对策

数学建模是一种数学思想方法,可以帮助学生灵活地综合地应用所学的知识来处理和解决一些现实生活中的问题.文章首先对数学建模的步骤、数学建模能力作了介绍;接着分析学生在数学建模中存在的问题,并针对问题提出培养和提高学生数学建模能力的对策.     

ERP软件供应商投资决策方法研究

中小企业在我国占有重要地位,但是中小企业的信息化程度并不理想,很多中小企业因为费用、员工素质等原因没有条件实施ERP软件。ERP提供商如何改进自己的投资方向,从而获得中小企业这一长尾市场的青睐,是现在ERP厂商需要考虑的问题。对江苏25个中小企业进行ERP需求的调查,并运用层次分析法,得出判断哪个方案更符合中小企业需求的方法,对ERP厂商选择方案很有意义。     

基于QualNet的战术数据链三维动态仿真

基于QualNet仿真软 件设计并实现了战术数据链在模拟环境下的三维动态仿真。将战术数据链仿真拓展到三维空 间,加入目标的机动性因素,给出了三维仿真的动态模型及其满足的更普遍关系式,具有一 定的参考价值和指导意义。     

技术模仿、技术创新的战略选择模型和经济增长

一国技术水平程度的高低在很大程度上影响和决定了该国经济发展的水平和经济增长的速度,技术水平提高的途径主要有两种:技术模仿和技术创新.但技术创新并不只是发达国家的"专利",技术创新除了与人均资本存量和人均人力资本水平有关外,也与总体的人均资本存量和人力资本水平有关.本文将国家技术发展战略分为四类,并给出了各种不同技术发展战略的情景条件.     

Incorporating textual information in customer churn prediction models based on a convolutional neural network

This study investigates the value added by incorporating textual data into customer churn prediction (CCP) models. It extends the previous literature by benchmarking convolutional neural networks (CNNs) against current best practices for analyzing textual data in CCP, and, using real life data from a European financial services provider, validates a framework that explains how textual data can be incorporated in a predictive model. First, the results confirm previous research showing that the inclusion of textual data in a CCP model improves its predictive performance. Second, CNNs outperform current best practices for text mining in CCP. Third, textual data are an important source of data for CCP, but unstructured textual data alone cannot create churn prediction models that are competitive with models that use traditional structured data. A calculation of the additional profit obtained from a customer retention campaign through the inclusion of textual information can be used by practitioners directly to help them make more informed decisions on whether to invest in text mining.     

基于分层线性模型的开发区工业用地集约利用影响因素研究

研究目的:针对以往工业用地集约利用影响因素研究仅考虑单一层次且多集中于宏观、中观尺度的问题,尝试从微观企业尺度分析企业、开发区两层因素对工业用地集约利用的影响。研究方法:综合评价法和分层线性模型。研究结果:江西省开发区企业土地集约利用水平总体偏低,在地域分布上呈现出赣北赣东赣西赣中赣南的特征,与开发区土地集约利用水平地域分布一致;开发区企业用地集约度受到企业和开发区两个层次影响。企业层次主要受企业规模、企业所有制、行业类型、研发投入和初始基础设施影响;开发区层次主要受开发区级别、工业用地率和土地利用集约度影响,并且通过影响企业资本类型、研发投入和初始基础设施的系数对企业用地集约度产生加成效用。研究结论:分层线性模型有效解决了开发区企业土地集约利用影响因素的结构分层和嵌套问题,揭示了开发区企业土地集约利用影响因素与机制,研究结果为研究区有针对性的制定土地集约利用政策提供一定依据。