Extracting patterns from Twitter to promote biking

Emphasis on non-motorized travel modes (for example, biking) reduces motorized trips and provides positive effects on the environment and the quality of human life. Understanding factors that influence people to biking or bike commuting can help decision makers, transportation planners, and bike commuting networks. Historically, conventional methods like surveys and crash data analyses were conducted to understand relevant factors. Survey and crash data analysis are difficult to perform in broad scale due to data availability and efforts. An innovative approach to determining these factors is to conduct social media mining to understand sentiments or motivations of bike commuters. People use terms (with hashtag at the beginning of the term) in Twitter, a popular social media network, to express their thoughts, activities or information. This study developed a framework for using Twitter data in understating the sentiments of the bikers with minimal effort. In this study, Twitter data associated with bike commuting hashtags were obtained for eight years (2009–2016). This study provided a framework of data collection and application of various natural language processing (NLP) tools (for example, text mining, sentiment analysis) to extract knowledge from the unstructured text data. Findings show that biking is associated with weather and seasonal patterns. The general sentiment towards biking is positive. However, negative sentiments are associated with bad weather, crime, and other challenges. The polarity scores indicate somewhat positiveness in the recent few years. The developed framework and the findings of this study will help planners and decision makers to promote biking on a broader scale.     

Transport pricing and Public-Private Partnerships in theory: Issues and Suggestions

This chapter offers a theoretical examination of the following questions: what are the issues that arise when Social Marginal Cost Pricing is to be incorporated in Public-Private Partnerships (PPPs); and how may these issues be dealt with?We first briefly discuss Public-Private Partnerships in transport: what are the defining characteristics and what are the main types that exist in the different modes of transport? Next we consider the economics of Public-Private Partnerships, in particular from the viewpoint of incentives. Subsequently we identify and examine the issues that arise when Social Marginal Cost Pricing is to be incorporated in PPPs as a regulation with regard to pricing in the transport sector. Lastly, we investigate the possibilities of resolving these issues.     

饱和多孔介质冻融过程的混合物连续介质理论

应用混合物的连续介质理论,建立了冻融过程中饱和多孔介质的渗流场、应力场和温度场耦合作用的数学模型。该模型以多孔骨架位移、水头和温度为基本变量,包括水总质量守恒方程,总应力平衡方程和总能量守恒方程。该模型可简化为未冻区域内的三场耦合模型,两场耦合的渗流-弹性模型,热-弹性模型和热-渗流模型,以及单场作用的渗流模型,弹性模型和热传导模型。     

混沌参数可变序列的流媒体加密算法

针对现有流媒体加密算法在安全性、通用性和实用性方面存在的缺陷,提出一种全新的基于混沌参数可变序列的流加密算法.该算法利用多层次迭代、密钥实时改变的思想,提高了安全性能.另外,本算法以流式加密为基础,采用直接加密的方式,使其适用于不同的视频编码标准,并且易于硬件实现.通过理论分析和实验结果,进一步证实了此算法具有很好的保密性和实时性.     

Application of multi-criteria decision analysis methods for assessing walkability: A case study in Porto Alegre,Brazil

The concept of walkability refers to the extent to which a neighbourhood is walking-friendly. Several walkability indexes have been developed to quantify and evaluate the pedestrian environment. These indexes differ in terms of type of data, methods and goals. The indexes variables may present either uniform or distinct weights, defined by arbitrary, empirical or other diverse weighting methods. This paper pursues the determination of a weighted walkability index, constructed on the basis of the relative importance of their attributes. Weights were determined by the application of the Fuzzy Analytic Hierarchy Process (FAHP), a robust multi-criteria method which considers the experts’ uncertainty in decision making. Moreover, FAHP weights were compared with the attribute weights obtained from other simpler methods, and a chi-square test for homogeneity was computed to compare the obtained values. The three most important walkability attributes were: Public Security, Traffic Safety and Pavement Quality, similar results to the ones found in the literature. The application to a case study in the city of Porto Alegre, Brazil, allowed categorizing the studied neighbourhoods and to analyse the effect of changes on attributes in walkability.     

Role model advocacy for sustainable transport

Individual aspirations of associating with role models are routinely harnessed by marketers, who for instance, use celebrity endorsement in selling brands and products. It appears there has been no research to date, however, on the potential for celebrity activism, or role model advocacy beyond celebrities, such as from politicians, to form effective interventions for encouraging sustainable transport behavior. This is despite studies suggesting that celebrity endorsement is a potential gateway for transforming public opinion on carbon intensive transport modes. The present paper consequently offers a critical review of the literature on role model advocacy and celebrity activism, and how these concepts have been harnessed to address environmental issues, in order to conceptually assess the potential for extending these intervention techniques to the context of sustainable transport. The scope of the paper includes the potential that high profile politicians/celebrities might play as role models in exercising referent power to influence social norms surrounding sustainable transport, given that the success of social marketing interventions are closely tied to the need for changes in the policy landscape. Key dimensions of role model endorsement in transport are identified and applied to a series of examples of how celebrity and political role models have influenced transport cultures. In addition to offering an original application of a theoretical framework to a new context, in order to help address the increasingly important societal issue of transport’s growing contribution to climate change, the paper discusses the challenges associated with the neoliberal framing of this approach.     

Social welfare analysis of investment public–private partnership approaches for transportation projects

This paper has two objectives: (i) to introduce a new approach in order to gain widespread support for road pricing; and (ii) to develop a detailed social welfare analysis for road pricing schemes. We first describe our novel approach that stimulates public support for road pricing, which we refer to as an investment public–private partnership, or IP3. This approach returns a significant portion of the economic value created by road pricing back to the citizens who own the newly priced facility. We then present a social welfare framework that estimates the benefits and costs of using the IP3 approach on an urban transportation network. A P3 project’s impact on overall social welfare provides a more comprehensive evaluation criterion than the often-used Value for Money (VfM) analysis. Apart from several theoretical studies, a detailed social welfare analysis that includes all major P3 project stakeholders is absent from the literature. We use Fresno, California as our case study in order to conduct a welfare analysis on IP3s. Our results show that system-optimal tolling favors average users, but that government—and consequently taxpayers—should pay for costly tolling systems (negative profits). In contrast, unlimited profit-maximizing tolls raise substantial profits for government, for the infrastructure’s citizen-owners, and for the private sector, but the average user is worse off. From a social-welfare perspective, one should search for a Pareto improvement under which all major stakeholders are better off. Our estimates indicate that a mixed public and private tolling scheme offers such an improvement.     

论新闻媒介的私人物品性

新闻媒介大多数是私人物品。只有在作为私人物品提供不了或提供不好时,才应作为公共物品。当代新闻媒介的发展趋势,主要是向私人物品转化和扩展。我国新闻传媒的市场化运作和企业化转制正符合这种趋势。事业性传媒的改革,也要重视私人物品的运行规律,尽力提高市场竞争力。     

我国传媒业发展的软着陆现象

本文对我国传媒业现有的生态环境，近20年来我国经济包括传媒业改革开放的实践，以及我国国情对传媒业发展的制约和影响诸方面进行了分析，认为我国的传媒业在入世以后的发展，固然会增加一些变数，但并不会发生危机，我国传媒业受国外强势媒体的冲击，其负面影响也并不会那么严重，入世，对我国传媒业的影响并不是一种突然的停滞和休克，而是会呈现和国际逐渐接轨的软着陆现象。