Proportional Odds Models with High‐Dimensional Data Structure

The proportional odds model is the most widely used model when the response has ordered categories. In the case of high‐dimensional predictor structure, the common maximum likelihood approach typically fails when all predictors are included. A boosting technique pomBoost is proposed to fit the model by implicitly selecting the influential predictors. The approach distinguishes between metric and categorical predictors. In the case of categorical predictors, where each predictor relates to a set of parameters, the objective is to select simultaneously all the associated parameters. In addition, the approach distinguishes between nominal and ordinal predictors. In the case of ordinal predictors, the proposed technique uses the ordering of the ordinal predictors by penalizing the difference between the parameters of adjacent categories. The technique has also a provision to consider some mandatory predictors (if any) that must be part of the final sparse model. The performance of the proposed boosting algorithm is evaluated in a simulation study and applications with respect to mean squared error and prediction error. Hit rates and false alarm rates are used to judge the performance of pomBoost for selection of the relevant predictors.     

港口物流化发展的现实意义分析——以广州港南沙港区为例

南沙港区是广州港外移发展大型深水港区的战略举措,是广州城市和产业空间格局南拓的前沿和支撑点。本文深刻剖析南沙港区物流化经营的现实意义即迫切性和现有条件,以促进其更加健康、快速地发展。     

The future of the mobile phone business

One of the fastest growing technologies of our times is that of mobile phones. In this article we use the assumption that the diffusion of mobile technology, as measured by the number of active mobile accounts, follows the well known S-curve of natural growth in competition systems. The accuracy of the logistic fit is tested against actual data for the whole world, Europe, China and the GSM system. Using the produced models predictions concerning the future of mobile business are deliberated.According to these models active mobile accounts around the globe are expected to grow from 1.7 billion in 2004 to approximately 2 billion in 2008, reaching a peak penetration of 29.2%. Growth barriers, apart from the age of the potential user, are also low income and extreme poverty. Europe, early adopter of mobile technology and leader in active mobile accounts against all other regions in the world, has apparently reached a peak with almost every European, apart from the very young or very old, using a mobile phone. The mobile market in China is anticipated to exceed 500 million active accounts and may increase even further depending on the economic and social reform that is currently under way in that part of the world. GSM will most likely remain the leading mobile technology in the future as it is today.The growth process for the world, Europe, and the GSM system is almost completed and during this stage instabilities may occur before the potential emergence of a new wave of growth.     

上市公司股权制衡的混沌模型

上市公司股权结构问题一直是公司治理的焦点,目前的研究都运用线性研究方法,但其得出的结论往往很难解释呈现非线性的经济现象。本文的创新之处在于:运用新经济理论与混沌理论相结合的非线性思维的方法,利用最新的上市公司财务数据分析了大股东的最佳持股比例范围,设计了上市公司大股东持股的混沌模型,从而得出第一大股东持股比例范围在(0,19.21%)为佳,并在此基础上利用Logistic方程,构建了理想的上市公司股权制衡模型。     

我国服装企业库存问题刍议

文中针对服装企业特点,分析了服装库存利弊和库存问题产生的原因,提出了解决我国服装企业库存问题的对策和建议。     

我国能源上市企业财务危机预警研究

不同行业的财务指标与非财务指标有着不同的特征,而这些指标是构建财务危机预警模型的基础,因此有必要分行业进行财务危机预警研究。以我国能源行业上市企业为研究对象,对其预警指标进行分析,最终选取了10个能显著反映能源上市企业财务情况的指标,运用Logistic回归法构建预警模型,模型预测准确率达到了90％。     

行业因素对综合预警模型的判别效果的影响研究--以基于主成分分析的Logit模型为例

以2010～2012年期间我国沪深A股因财务困境陷入ST的公司和按照1∶2比例配比的正常公司作为研究对象,并根据行业特点对样本进行划分。同时,选取能够反映企业盈利能力、股东获利能力、现金流量能力、营运能力、发展能力、偿债能力的30个财务指标,在主成分分析的基础上构建各年度的Logit模型,对各行业的违约概率和判别准确度分别进行分析。结果表明,不同行业的违约概率和判别准确度均存在显著差异且存在共性特征。     

我国上市公司财务困境预测模型分析——基于我国A股上市公司研究

基于我国A股市场上市的ST公司和相对应的非ST公司,用Logistic回归的进入法和逐步法对上市公司财务困境预测模型进行了比较分析,得出结论:无论是模型的有效性,还是模型的判断准确率方面,Logistic回归的进入法均优于逐步法。     

农业产业化联合体实现机制及其决定因素——基于家庭农场调查数据的实证分析

[目的]农业产业化联合体是我国乡村产业融合发展的高级形态,对农业现代化起关键作用。探究家庭农场对联合体的满意情况及其影响因素,对于联合体的持续稳定发展有重要的现实意义。[方法]文章利用2020年对安徽合肥、亳州、六安和宿州等9个地市的农业产业化联合体调查数据,分析了安徽省各地区、各生产类型的家庭农场对农业产业化联合体满意情况,并对满意度影响因素采用多分类有序Logistic回归模型进行了实证分析。[结果]各地区的家庭农场对联合体的满意情况存在一定差异,但不同类型的家庭农场满意差距不大。家庭农场满意度受到结构因素的影响,其中种养规模、共同目标制定、沟通程度对满意度产生正向影响,而文化程度与机会主义行为对满意度产生了负向影响。过程因素中的合同履行与监督制度对满意度产生正向影响,结果因素中体现经济与社会效益的利润率增长和劳动力带动对满意度有正向影响。[结论]积极扩大家庭农场的生产规模、完善联合体的监督管理制度、加强利益联结等措施是实现农业产业化联合体可持续发展的关键。     

农业供应链金融视角下核心企业信用风险实证研究

如何对核心企业信用风险进行评价与控制成为农业供应链金融稳定运行的关键点之一.基于农业供应链金融视角,在梳理以核心企业为主导的农业供应链金融模式基础上,结合因子分析构建二元Logistic回归模型,对影响农业供应链金融中核心企业信用风险的因素进行分析.结果表明,该二元Logistic回归模型能够较好地预测农业供应链金融中核心企业的信用风险.其中,总资产周转率、流动资产周转率、应收账款周转率越高,核心企业的信用风险越低.