Are they telling the truth? Revealing hidden traits of satisfaction with a public bike-sharing service

Public bike-sharing systems (BSSs) are an emerging mode of transportation introduced by municipalities to solve congestion problems in metropolitan areas, especially when integrated with other types of transportation. In the last years, the number of public bike-sharing services has been constantly on the rise all over the world, and generally the overall satisfaction with them is high. However, satisfaction with public services is driven by mechanisms that can differ from those in the private sector. It is important to establish to what extent a high satisfaction is genuine or simply ephemeral. Even “old” public services (like public transportation) become “gold” when accompanied by the introduction of new technologies. In this paper we analyze this phenomenon using data from a satisfaction web-survey conducted among customers of the public BSS “BikeMi” in Milan, Italy, in a period when mobile technologies have been introduced to speed up the service. On analyzing the responses to satisfaction questions using simple summary statistics, the level of satisfaction resulted very high. However, our aim was to look for potential “darker” sides of the service by detecting possible hidden satisfaction components. For this purpose, we used the Nonlinear Principal Components Analysis, which is particularly powerful in this context. A simple textual analysis was also performed as a validating test. Results from our analysis indicated that satisfaction is flawed by a set of factors like the mechanics of the bikes, the picking and dropping system, and the apps used to organize the service. Less concern was detected for more general aspects of the service.     

Exploring pilgrim satisfaction on facilities for religious events: a case of Ratha Yatra at Puri

This article relates to the annual Ratha Yatra festival at Puri, India, and aims at quantifying the pilgrim perception of the event on three major aspects of every facility – adequacy, quality, and signage – to measure their satisfaction. A questionnaire survey (N?=?680) was conducted, from which a five-factor structure was extracted using exploratory principal component analysis, further examined through partial least squares-path modeling. The final model was found to have significant positive effects on three factors that comprised adequacy and quality of physiological needs, quality of ancillary facilities, and signage. The outcome may be utilized in planning other pilgrim events for achieving a higher pilgrim satisfaction score.     

水源地突发水污染政府应急预留水量需求预测

近年来,随着工业化和产业化的快速发展,水源地突发水污染事件频发。为应对紧急情况下的水资源非常规需求,保障经济社会稳定发展,政府需要安排一部分应急预留水量。如何合理预测政府应急预留水量的规模是一个值得探讨的课题。提出了一种基于案例推理技术的政府应急预留水量需求预测方法,具体思路是:借助于案例库,利用主成分分析法从众多影响水源地突发水污染事件的因素中提取出两两不相关的因子,以此作为案例的特征属性,基于加权曼哈顿距离测算相似度,依此得到匹配案例,进而测算政府应急预留水量。以太湖流域常州地区水源地为例,进行政府预留水量需求量的预测与分析。该方法可以为政府应急预留水量的配置、储备等提供相关理论知识。     

国有林场改革成效评价——职工获得感的统计分析

利用国有林场职工监测数据,基于物质维度和精神维度,从改革后职工自身的收益情况、职工对林场的整体评价、职工对林场管理方式的评价等方面,采用比较分析法和主成分分析法对国有林场改革职工获得感进行分析。研究结果表明:国有林场改革后职工获得感有所提升,改革进程与职工获得感呈强正相关性,改革促进了林场的可持续发展。但林场整体基础设施环境一般,场部相对较好,管护站点则较差。同时,在领导班子建设方面应注重自主、公平,仍需提高领导水平。     

基于主成分分析的关中—天水经济区水资源承载力评价

[目的]通过探讨关中—天水经济区水资源状况,可为经济区水资源的合理配置与经济社会的协调、可持续发展提供决策参考。[方法]根据关中—天水经济区2007~2016年相关统计资料,采用主成分分析法和构建指标体系对经济区水资源承载力从时间和空间两个角度进行综合评价。[结果](1)经济区水资源承载力得分由2007年的-0.067增加至2016年的1.877,水资源承载力与开发利用潜力呈现由大到小的变化,而水资源开发利用强度则呈逐渐增大趋势。(2)经济区各地市间水资源承载力存在显著差异,西安、咸阳两地的水资源承载力得分最高,均超过1.300,但水资源承载力和开发利用潜力最小;而杨凌、铜川两地的水资源承载力得分最低,均小于-2.250,但水资源承载力和开发利用潜力则最大。(3)经济发展水平、人口数量、水资源供需量、工农业生产用水是影响经济区水资源承载力大小的主要因素;其中,经济发展水平的贡献最大。[结论]经济区水资源承载力与开发利用潜力变小,开发利用强度增大;各地市间水资源承载力差异显著,将在一定程度上对经济区人口、经济、环境可持续发展起着明显的制约作用。为了促进经济区经济社会的健康可持续发展,应加强对水资源的管理与废水处理,合理控制经济区人口容量,提高社会节水意识,转变经济发展模式,大力推行节水型与节约型经济发展道路。     

A functional time series analysis of forward curves derived from commodity futures

We study forward curves formed from commodity futures prices listed on the Standard and Poor’s-Goldman Sachs Commodities Index (S&P GSCI) using recently developed tools in functional time series analysis. Functional tests for stationarity and serial correlation suggest that log-differenced forward curves may be generally considered as stationary and conditionally heteroscedastic sequences of functions. Several functional methods for forecasting forward curves that more accurately reflect the time to expiry of contracts are developed, and we found that these typically outperformed their multivariate counterparts, with the best among them using the method of predictive factors introduced by Kargin and Onatski (2008).     

结合新型模糊支持向量机和证据理论的多传感器水质数据融合

在多传感器水质数据融合领域，证据理论是有效的数据融合方法之一，但基本概率分配一般不易确定，从而使数据融合能力难以有效发挥。支持向量机是统计学习理论之上的高级分类算法，具有普适性和全局优化等特点，但输出的基本概率分配有待进一步提高。提出了一种基于证据理论和新型模糊支持向量机相结合的数据融合方法，通过建立基于分类超平面距离的模糊隶属度，训练模糊支持向量机提高传统支持向量机的基本概率分配，并结合证据理论进行海河水质数据融合。通过证据理论分别结合支持向量机和模糊综合评价法与上述方法进行对比实验，经精度、平均绝对百分误差、均方根误差等指标验证，精度提高10.5%，表明所提方法是一种可靠的多传感器的水质融合方法，较其他方法具有更高的融合精度。     

基于乡村振兴战略的青岛市农村基础设施提档升级驱动力分析

[目的]为了全面贯彻实施乡村振兴战略,以建设美丽乡村为导向,研究影响青岛市农村基础设施提档升级的驱动因子,为青岛市农村现代化建设和城乡协调发展提供理论依据。[方法]文章利用主成分分析法对青岛市农村基础设施的基本情况和影响因素进行分析,通过技术各因子之间的相关系数、特征值和贡献率分析影响青岛市农村基础设施提档升级的主要因素。[结果]青岛市农村基础设施一直处于升级的状态,主成分分析结果表明第一主成分和第二主成分可以代表绝大部分信息,第一主成分与X1(农村居民人均纯收入)、X2(乡村人口)、X4(农业产值)、X6(农村恩格尔系数)、X7(工业生产总值)具有很大的相关性,第二主成分与X3(农用机械总动力)、X5(固定资产投资)具有明显的相关性。[结论]经济发展因素和农业人口因素是影响青岛市农村基础设施提档升级主要驱动力。为了进一步提高农村基础设施建设,政府应该增加固定资产的投入,重点整治农村污染和公共卫生,加强村容村貌整治,促进青岛市美丽乡村的全面建设。     

基于景观适宜性的山地公园植物景观 评价研究——以贵阳黔灵山公园为例

以贵阳市黔灵山公园为研究对象，选取24个植物景观单元。以生态适宜、景观适宜、社会适宜为准则层，建立山地公园植物景观景观适宜性评价体系。运用主成分分析确定评价指标权重，克服以往植物景观评价赋权重的主观性，建立山地公园植物景观景观适宜性评价模型，得到不同植物景观的景观适宜性指数。结果表明：黔灵山公园在适宜范围内的植物景观有10个，占评价单元总数的41.6%，适宜性较差的有14个，乔灌比(数量)在1:11.2~1.7:1之间的植物群落景观适宜性较好。根据评价结果，提出了3点山地公园植物景观营建策略，以期为山地公园植物景观评价及营建提供理论指导。     

The long breadth of cities: revisiting worldwide urbanization patterns, 1950–2030

ABSTRACT

A comparative analysis of population dynamics worldwide contributes to profile distinctive demographic and economic trajectories of urban growth, discriminating processes of settlement concentration or dispersion under sequential cycles of urbanization. However, a wide-ranging characterization of urban cycles based on demographic dynamics worldwide is still missing. The present work is aimed at filling such a gap analysing long-term changes (1950–2030) in annual population growth rate of 1691 urban agglomerations with more than 300,000 inhabitants in 74 world countries. Results of this study indicate that metropolitan growth worldwide was associated with largely variable rates of population growth, highly positive before 2000 and progressively reducing over recent decades. Despite important differences at continental (and country) scale, demographic expansion of urban agglomerations showed two contrasting phases with a break point in the 1980s denoting a progressive reduction in spatial heterogeneity of population growth rates and a moderate slowdown in demographic dynamics. Intensity of urban expansion and spatial heterogeneity in population growth rates across metropolitan agglomerations evidences a trade-off between fast and slow demographic dynamics. These findings can be better understood to support theories of sequential city growth, making a suitable contribution to policy making, especially in countries where urban population is expanding more rapidly.