Separate waste collection in mountain municipalities. A case study in Campania

This paper aims to analyse the impact of land characteristics (i.e. altimetry and housing dispersion) on separate waste collection, with a focus on mountain municipalities. The high spatial heterogeneity of the driving factors of separate waste collection allows traditional techniques, such as OLS, to offer only a partial depiction of the situation, missing important information. In this view, we perform the Geographically Weighted Regression (GWR), which allows to control for the local determinants of waste management. Our data cover 550 municipalities of Campania, in Southern Italy. We control for a set of morphological and socio-economic variables, drawn from official records for 2012. Our results show that the relationships between land characteristics and separate waste collection are not constant over space. Moreover, they suggest that in the presence of non-modifiable factors (such as land characteristics) local governments should act on citizen motivations, promoting awareness on environmental issues, and should implement time-saving collection methods.     

机场噪声预测与计算

采用计权等效连续感觉噪声级LWECPN作为机场噪声评价参数,具体结合机场及周围地区的地形、航班、机种及飞机起降航迹等计算并绘出机场周围地区的等声级噪声暴露图。     

The Impact of Personal Taxes on the Firm's Weighted Average Cost of Capital and Investment Behaviour: A Simplified Approach Using the Dempsey Discounted Dividends Model

The discounted dividends model advanced by Dempsey (1996) is extended to provide a weighted average cost of capital (WACC) assessment of investment opportunities with irregular cash flows. Thereafter, the framework is extended to an assessment of the implications of government tax policy for the firm's investment behaviour. The developed framework is consistent with the empirical evidence of Poterba and Summers (1985) which — over the period of UK tax history 1950–1983 encompassing four major tax on equity reforms — observes how the related dividend and investment politics of UK firms appear to be influenced by the level of dividend taxes.     

Optimal constrained investment in the Cramer-Lundberg model

We consider an insurance company whose surplus is represented by the classical Cramer-Lundberg process. The company can invest its surplus in a risk-free asset and in a risky asset, governed by the Black-Scholes equation. There is a constraint that the insurance company can only invest in the risky asset at a limited leveraging level; more precisely, when purchasing, the ratio of the investment amount in the risky asset to the surplus level is no more than a; and when short-selling, the proportion of the proceeds from the short-selling to the surplus level is no more than b. The objective is to find an optimal investment policy that minimizes the probability of ruin. The minimal ruin probability as a function of the initial surplus is characterized by a classical solution to the corresponding Hamilton-Jacobi-Bellman (HJB) equation. We study the optimal control policy and its properties. The interrelation between the parameters of the model plays a crucial role in the qualitative behavior of the optimal policy. For example, for some ratios between a and b, quite unusual and at first ostensibly counterintuitive policies may appear, like short-selling a stock with a higher rate of return to earn lower interest, or borrowing at a higher rate to invest in a stock with lower rate of return. This is in sharp contrast with the unrestricted case, first studied in Hipp and Plum, or with the case of no short-selling and no borrowing studied in Azcue and Muler.     

融合反距离加权和矩阵填充的位置指纹库构建

为解决位置指纹定位在离线阶段构建位置指纹库时耗费的人力和时间成本较大,构建指纹库效率低和利用空间插值法构建的指纹库精度不高的问题,提出了一种融合反距离加权和矩阵填充的位置指纹库构建算法。该算法仅需人工采集定位区域内少量参考点的接收信号强度值用作信标点指纹信息,结合反距离加权算法特性计算出次信标点指纹信息,根据位置指纹库数据矩阵的低秩性,应用奇异值阈值矩阵填充算法构建出位置指纹数据库。仿真实验结果表明,所提算法有效降低了矩阵填充算法构建位置指纹库所需的人工和时间成本,构建出的位置指纹库定位性能优于反距离加权和克里金空间插值法,接近传统人工采集法,显著地提高了位置指纹库的构建效率。     

中国省际工业绿色化评价及空间差异性研究

从资源消耗绿色化、废物排放绿色化与工业转型绿色化三方面构建工业绿色化评价指标体系,基于2007—2016年30省面板数据和加权TOPSIS方法对中国工业绿色化水平进行评价,并利用泰尔熵指数、基尼系数和变异系数对省际工业绿色化空间差异性进行阐述。结果表明：（1）省际工业绿色化水平由高到低依次为东部地区、中部地区、西部地区和东北地区;东部地区稳中有升,中西部地区相对稳定,东北地区下降趋势显著。（2）省际工业绿色化空间差异性总体变化幅度不大,且以泰尔熵指数、基尼系数与变异系数测度的省际工业绿色化空间差异性变化趋势呈现出明显同步性。（3）通过对泰尔熵指数空间分解发现,地区内的省际工业绿色化空间差异性不断变小,而地区间的省际工业绿色化空间差异性小幅变大。     

北京市二手住宅价格影响机制——基于多尺度地理加权回归模型(MGWR)的研究

文章基于多尺度地理加权回归研究北京市2011—2017年二手住宅交易的价格特征,结果表明:①以往基于经典地理加权回归模型的研究可能存在一定的不稳健,而多尺度地理加权回归可以将不同变量对于因变量的影响尺度反映出来,其回归的结果更为可靠。②北京房价对区位因素非常敏感,且存在高度的空间异质性,区位的影响尺度是所有变量中最小的,接近于街道尺度。而卧室数量和到最近地铁站的距离为全局尺度的变量,在空间上的影响较为平稳。到公交站的距离、到小学的距离、建筑结构和装修状况对于房价的影响不显著。其他显著的变量均存在一定的空间异质性,其空间尺度由小到大分别为成交时间、面积、楼龄、楼层、朝向。③区位、朝向、卧室数量、成交时间均正向影响房价,而面积、楼龄、楼层、到地铁站的距离负向影响房价。所有影响因素中区位是影响房价的最主要因素,其次是成交时间朝向。面积成交时间、朝向和到最近地铁站的距离影响较大,所在楼层、卧室数量对于房价的影响较小,而面积和楼龄的影响最弱。     

行为金融:过度自信与混合期望收益模型

本文以投资者的过度自信心理为基础,研究了投资心理对证券期望收益的影响,并基于投资者的理性心理和过度自信心理建立了混合期望收益模型,证明了CAPM模型为混合期望收益模型的特殊模型,当不存在过度自信投资心理时,混合期望收益模型退化为CAPM模型.     

Simultaneous Parameter Estimation in Exploratory Factor Analysis: An Expository Review

The classical exploratory factor analysis (EFA) finds estimates for the factor loadings matrix and the matrix of unique factor variances which give the best fit to the sample correlation matrix with respect to some goodness-of-fit criterion. Common factor scores can be obtained as a function of these estimates and the data. Alternatively to the classical EFA, the EFA model can be fitted directly to the data which yields factor loadings and common factor scores simultaneously. Recently, new algorithms were introduced for the simultaneous least squares estimation of all EFA model unknowns. The new methods are based on the numerical procedure for singular value decomposition of matrices and work equally well when the number of variables exceeds the number of observations. This paper provides an account that is intended as an expository review of methods for simultaneous parameter estimation in EFA. The methods are illustrated on Harman's five socio-economic variables data and a high-dimensional data set from genome research.