在数学建模中培养学生创新性思维及建议

本文论述了数学建模对培养学生创新能力、提高综合素质的重要作用,指出大学生创新性思维能力的培养是数学建模活动的核心目标,对在数学建模活动中如何培养学生的创新性思维能力作了讨论,并根据学校开设数学建模课程及参加数学建模竞赛活动的现状,就如何提高数学建模成绩提出了一些建议.     

When do B2B brands influence the decision making of organizational buyers? An examination of the relationship between purchase risk and brand sensitivity

The dominant perspective on organizational buying behavior suggests that buyers tend to rely on objective criteria when making product choice decisions and that the potential influence of subjective cues, such as brands, on buyer decision making decreases with increasing risk. An alternative perspective, confirmed in this study by in-depth interviews with various managers, suggests that brands serve as a risk-reduction heuristic, whereby the influence of brands on decision making increases as a function of risk. Building on risk and information processing theories, this research builds on these complementary perspectives to propose that risk and brand sensitivity relate in a U-shaped manner, where brand sensitivity is highest in relatively low- or high-risk situations. The results of scenario- and survey-based field studies—involving 206 and 180 members of buying centers, respectively—suggest that both perspectives have merit and support the proposed nonlinear relationship. Moreover, the findings reveal that the risk-brand sensitivity relationship is moderated by competitive intensity, such that the linear (negative) and quadratic (positive) effects are stronger when competitive intensity is low.     

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.     

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.     

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。     

亚洲工厂及关联度分析

依据亚洲零部件贸易数据,作者采用了依存比率的方法对亚洲工厂的规模、工厂内部以及同美国之间的相互依存关系进行了研究。研究结果发现,亚洲工厂的规模超过北美洲和欧洲工厂,成为了世界上最大的工厂。亚洲零部件内部贸易额及比重超过了欧盟,这说明亚洲生产的一体化程度更高。从零部件进出口规模角度看,亚洲地区的经济体均高度依赖亚洲工厂的活动,而亚洲工厂对中国的依存度则最高,对日本的依赖程度只排在第三位,这说明中国是亚洲工厂的核心平台。美国在亚洲贸易中的重要性主要体现为中国的最终产品出口对美国市场存在严重依赖,而亚洲主要经济体对中国市场的出口已经超过对美国的出口,亚洲工厂对于美国的依赖程度并不高,远远低于亚洲工厂对中国内地和中国香港的依赖。相反,美国对亚洲工厂的依赖程度则远高于亚洲工厂对美国的依赖。     

市场均衡、效应锁定和控制权拿捏:由我国风电产业生发

对风电产业发展路径依赖效应的研究表明,传统资源模式下对原有经济制度、能源禀赋、传统技术和现有产业结构的路径依赖严重制约我国风电产业的推广和发展。应尽快制定科学、合理的风电产业政策体系,按照市场经济规律的要求,运用法律、财政、税收、信贷等手段调节或影响市场主体的行为,破解我国风电产业发展难题。     

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.     

中国东北三省与“一带一路”沿线国家贸易格局时空演变

利用2003年~2017年东北三省与"一带一路"沿线国家进出口贸易数据,采用地理集中度、位序变动指数、综合贸易份额指数、HM指数分析东北三省与沿线国家贸易格局及特征的变化。结果表明:东北三省与"一带一路"沿线国家的贸易往来日益密切,贸易总额大幅增加,尽管东北三省与东北亚地区的贸易份额有所下降,但东北亚地区始终是东北三省的贸易重心。东北三省与沿线国家贸易依赖度不断提高,具有明显的不对称性,表现出显著的单向依赖。从进出口商品结构来看,东北三省向沿线国家出口的资源密集型和劳动密集型商品占比下降,技术密集型商品占比有较大提升,出口商品更加多元化,附加值和科技含量进一步提高,进口商品结构相对稳定,主要为资源密集型和技术密集型商品。