基于SARIMA-SVR组合模型的 空气质量指数预测

空气质量指数(AQI)在波动中既具有整体的时间序列线性特征和明显的季节性波动周期,又具有多种因素影响的不确定性,为了提高AQI的预测精度,基于Ri386 3.3.3和Matlab R2014a两种编程软件,提出了一种同时具有线性和非线性的复合特征的时间序列预测模型——SARIMA-SVR组合模型。以太原市2014年1月—2019年7月的AQI月均值数据为基础,利用SARIMA时间序列模型进行线性预测,利用SVR模型对残差进行非线性预测,加和得到组合预测模型的预测结果,分析比较SARIMA,SVR和SARIMA-SVR这3种模型的预测结果和平均绝对百分比误差。结果表明,组合预测模型发挥了2种模型各自的优势,相较于单一预测模型的预测结果而言,其预测精度更高,稳定性更好。通过此模型得到的空气质量预测结果不仅可为人们的日常生活提供指导,而且可为大气污染的防治工作提供科学依据和借鉴意义。     

基于组合赋权法的多谐波源责任综合评估

为区分多谐波源负荷对公共点的谐波责任,提出一种基于组合赋权法的多谐波源责任综合评估方法。将各次谐波电压含有率作为评估指标,采用优序图与熵权的组合赋权法得到的综合评价结果对谐波电压等级进行评估:定性分析了各负荷应负的谐波电压责任,定量比较了根据组合赋权法求得的加权谐波电压值。从主、客观方面采用组合赋权法对含有多谐波源系统进行责任综合评估,其评估结果客观、合理,具有一定的工程实际意义。     

基于模糊联系度的危化品公路运输安全风险评估

为了有效降低危化品公路运输事故风险,提高危化品运输安全管控能力,构建了含23个动、静态指标的危化品公路运输安全风险评估指标体系,采用组合权重对评估指标赋权;基于集对分析理论,对专家打分分值与组合权重深入分析,引入综合差异度系数的概念,确定模糊联系度,提出一种危化品公路运输安全风险评估方法;以西安某公司至上海的运输任务为例,进行实例应用。结果表明：除危化品因素外,其余一级指标均存在风险上升趋势,其中人员因素风险上升趋势尤其明显,危化品公路运输整体风险状态处于微反势9级,风险较大,与实际情况相符。所提方法可实现危化品公路运输动、静态风险评估,为危化品公路运输风险研究提供参考。     

制度创新与经济增长——一个理论分析框架及实证检验

任何经济增长过程都是在一定的制度环境中进行的,有必要将制度因素纳入经济增长理论当中。在新古典经济学框架下,本文通过理论模型分析,认为稳态下的经济增长率跟制度创新有着紧密的正向关的关系。在理论分析的基础上,本文基于1978～2012年的省际面板数据,利用半参数估计和线性回归估计方法,实证分析结果表明：国家财政干预的增强、国有经济的强化和垄断作用加强从整体上抑制了我国以及不同地区的经济增长,提高市场开放度和对产权的保护程度则对经济增长产生了积极的正向促进作用,制度差异是引起我国区域经济增长差异的重要因素之一,制度创新仍是当前我国经济增长的关键。     

Personality and the creativity of frontline service employees: linear and curvilinear effects

Abstract

Previous studies have investigated the relationship between the Five-Factor model of personality and creativity. As this model has been criticised for providing a limited account of an individual’s personality, this study considers additional personality traits that have recently been investigated in the literature as determinants of employee behaviour. Moreover, we also contribute to the existing body of literature by conducting this study in a service setting, for which we predict personality traits will exert differentiated effects on creativity when compared to other settings. Finally, while past research has focused on linear effects, this study examines the existence of non-linear effects between personality and creativity. The results indicate that personality traits apart from the Five-Factor model have an impact on creativity and that the effects of several personality traits on the creativity of frontline service employees differ from those obtained in other settings. Lastly, the findings also show that five of the personality traits have non-linear effects on creativity, and this may be a stimulus for a new stream of research in the human resources literature.     

我国热带水果分类及编码体系研究

按照科学性、系统性、综合实用性、唯一性、可扩充性和规范性等基本原则,按落叶果树和常绿果树再结合果实构造以及果树的生物学特性进行分类,便于热带水果的信息交换、管理、生产、统计等领域应用。将热带水果分为荔枝类、常绿果树浆果类、柑果类、香蕉类、常绿果树核果类等11个基本类型,在此基础上再分若干小类,采用线分类法对热带水果进行编码,编码结构由六层八位全数字型层次编码组成。     

对城市互通立交线形设计安全性探索和分析

城市互通立交线形设计过程中存在很多的安全影响因素,因此正确认识到这些安全隐患,对于提高道路的实用性和稳定性有着重要意义。     

Three Corrected Score Tests for Generalized Linear Models with Dispersion Covariates

We develop three corrected score tests for generalized linear models with dispersion covariates, thus generalizing the results of Cordeiro , Ferrari and Paula (1993) and Cribari-Neto and Ferrari (1995) . We present, in matrix notation, general formulae for the coefficients which define the corrected statistics. The formulae only require simple operations on matrices and can be used to obtain analytically closed-form corrections for score test statistics in a variety of special generalized linear models with dispersion covariates. They also have advantages for numerical purposes since our formulae are readily computable using a language supporting numerical linear algebra. Two examples, namely, iid sampling without covariates on the mean or dispersion parameter oand one-way classification models, are given. We also present some simulations where the three corrected tests perform better than the usual score test, the likelihood ratio test and its Bartlett corrected version. Finally, we present a numerical example for a data set discussed by Simonoff and Tsai (1994) .     

Locating a Biorefinery in Northern Spain: Decision Making and Economic Consequences

Biofuels are emerging as a prominent renewable and sustainable energy sources in developed countries. In this sense, this paper presents a case study in which a biorefinery has to be sited in Northern Spain. Thus, the strategic decision of locating such a facility is deeply investigated through strategic policy evaluation. Then, tactical decisions ranging from purchasing and transportation policies to storage protocols are carried out. Only local and limited biomass can be harvested for supplying the biorefinery through a heterogeneous vehicle fleet. Moreover two different and mutually exclusive storage strategies are evaluated: direct supply from crops to biorefinery and using intermediate-collectors. Additionally, crop exploitation factors and biorefinery sizes are used to generate several scenarios in which the strategic decision of location as well as all the tactic decisions are made. Some mixed integer linear programming models are proposed to figure out all relevant decision problems.The results suggest that the Northwest study area as the best option to locate the biorefinery and recommend the intermediate-collector storage strategy. Moreover, the key information about critical biomass, crops and times are also provided.     

Constrained Kalman Filtering: Additional Results

This paper deals with linear state space modelling subject to general linear constraints on the state vector. The discussion concentrates on four topics: the constrained Kalman filtering versus the recursive restricted least squares estimator; a new proof of the constrained Kalman filtering under a conditional expectation framework; linear constraints under a reduced state space modelling; and state vector prediction under linear constraints. The techniques proposed are illustrated in two real problems. The first problem is related to investment analysis under a dynamic factor model, whereas the second is about making constrained predictions within a GDP benchmarking estimation.