A Bayesian multivariate Poisson regression model of cross-category store brand purchasing behavior

The availability of cross-category transaction data in the retailing industry has enabled the investigation of interdependence in consumer purchase behavior across product categories. In this paper, we develop a multivariate count model to uncover and predict the pattern of cross-category store brand purchasing behavior. The proposed multivariate Poisson regression model, which we estimate using a Bayesian approach, provides flexibility in capturing cross-category correlations for sparse multivariate purchase data associated with infrequently purchased categories or purchasing in retail outlets such as warehouse clubs. We compare the goodness-of-fit of the proposed Poisson regression model with alternate benchmark models using customer purchase records across five product categories from a national warehouse club and find that the proposed model provides a superior fit. We also carry out a profitability analysis to illustrate the use of the model in planning cross-promotions.     

Are the dynamic linkages between the macroeconomy and asset prices time-varying?

We estimate a number of multivariate regime switching VAR models on a long monthly US data set for eight variables that include excess stock and bond returns, the real T-bill yield, predictors used in the finance literature (default spread and the dividend yield), and three macroeconomic variables (inflation, industrial production growth, and a measure of real money growth). Heteroskedasticity may be accounted for by making the covariance matrix a function of the regime. We find evidence of four regimes and of time-varying covariances. We show that the best in-sample fit is provided by a four state model in which the VAR(1) component fails to be regime-dependent. We interpret this as evidence that the dynamic linkages between financial markets and the macroeconomy have been stable over time. The four-state model can be helpful in forecasting applications and provides one-step ahead predicted Sharpe ratios.     

证券投资基金收益概率密度预测——基于神经网络分位数回归模型

证券投资基金收益往往具有更高的峰度与更大的偏度,建立在古典假定基础上的均值回归分析难以给出准确预测结果。考虑到证券投资基金收益中的高峰、非对称等典型特征与各因素对收益序列的非线性影响模式,建立神经网络分位数回归模型,一方面,可以通过分位数回归功能,揭示各因素对证券投资收益整个条件分布的影响规律;另一方面,可以通过神经网络结构,模拟金融系统中的非线性关系。在神经网络分位数回归模型基础上,对证券投资基金收益整个条件密度函数进行预测,提供比点预测更多的有用信息,便于进行科学决策。     

我国责任保险发展的影响因素研究

与发达国家相比,我国责任保险发展滞后,是保险业发展不足但潜力巨大的领域。基于经济理论和国际经验,采用2001—2012年（2013年）我国省级单位和地级单位的面板数据,分析影响我国责任保险发展水平的主要因素,结果表明：我国责任保险处于初级发展阶段,责任保险的赔付水平低于发达国家;我国责任保险赔付与宏观经济社会变量的相关性较弱,这与主要发达国家相同;我国责任保险赔付与医疗保健服务的使用、医疗保健服务价格指数、CPI的相关性弱于其与人均GDP、人均工资水平的相关性,这与主要发达国家相反。经济新常态下,我国责任保险发展应将环境污染、食品安全、医疗责任等与人们日常生活紧密相关的领域作为重点,并将责任保险嵌入社会风险管理的全过程。     

航空联盟对国际枢纽机场间机票价格的影响——以我国主要非经停国际航线为例的实证研究

本文通过构建多元回归模型,实证分析了航空联盟对我国主要非经停国际航线客运价格的影响。结果发现,在控制其他一些影响因素之后,航空联盟的存在并不一定会引起航线票价的上升。本文最后依据实证结果,给出相关对策建议。     

高密度电法在龙岩适中矿区锰矿探测中的应用

文章简要介绍了高密度电阻率法的基本原理,并详细分析了一个锰矿探测实例,通过理论与实践的结合,指出高密度电阻率法是一种有效的金属矿探测手段。     

组织密度对针织物悬垂性的影响

为了给针织面料的设计提供一定指导,利用手摇横机编织满针罗纹、罗纹空气层、畦编组织3种针织物,然后用YG（L）811-DN型织物动态悬垂风格测定仪来测定所编织针织物的悬垂性,通过实验数据来分析针织物组织密度对织物悬垂性的影响.结果表明,同一密度下,满针罗纹组织悬垂性最好,且3种织物密度越小,悬垂性也越好.     

Website and email adoption by Malaysian hotels

This research note addresses two limitations of Internet diffusion studies by highlighting the importance of multivariate statistical analysis and including the element of time. The results support findings on the positive relationship between two hotel characteristics – affiliation and category – with Internet adoption, but question findings on the relationship between hotel size and Internet adoption.     

GNSS系统中预积分时间内基带信号的功率谱密度研究

目前在进行全球卫星导航无线频率兼容性评估时,由于忽略了接 收端预积分时间对基带信号截断作用的事实,导致采用的短码功率谱密度计算方法有误,这 将影响到评估结果的精确性。针对这个问题,分预积分时间大于等于和小于伪码周期两种情 况,对基带信号的功率谱解析式进行推导,然后仿真不同预积分时间内实际信号的功率谱以 及解析式的功率谱,比较这两者的谱分离系数。仿真结果表明,预积分时间对短码的谱分离 系数影响很大,这正确反映了预积分时间对功率谱密度的影响。该功率谱解析式有助于精确 估计无线射频干扰。     

5G移动通信系统的下行控制信道传输

基于5G系统的控制信道结构和传输机制,通过多种场景下的性能仿真从而得到导频图案和聚合等级的优化准则。首先,用于解调控制信道的导频与控制信道采用相同的预编码以实现控制信道波束的透明传输;其次,控制信道在频域资源上打散,当信道状态未知则采用分集的传输机制;再次,导频分布随聚合等级的变化而调整,低聚合等级导频密度大,高聚合等级导频密度小。该方法可以根据信道状况是否可知采用波束赋形或分集的传输,实现控制信息的可靠、有效传输。