The scope and scale of the informal food economy of South African urban residential townships: Results of a small-area micro-enterprise census

Growing urbanisation in South Africa is reflected in burgeoning Working class and informal township settlements on the fringes of its major towns and cities. Paired with this is an increasing reliance on cash as the primary means of economic transaction, which has in turn stimulated the growth of micro-enterprise business activities within the township context. This article discusses the findings of an eight-township small-area census which occurred between 2010 and 2013 in Cape Town, Johannesburg, Ekurhuleni and Durban townships representing 250 000 residents. The researchers were able to establish the scope and scale of informal food and drink retailing in these localities. Of the 10 049 micro-enterprises located in the study, some 3966 (or 39% of the total) trade in food. These include enterprises in primary production, fresh produce retailing, grocery retailing from house and spaza shops, and informal foodservice enterprises. Food is the basis for much township informal business and plays an important role in making food increasingly affordable and locally accessible, and in creating cash employment. The article builds on the knowledge base of the township informal economy role in bolstering food security needs for the marginalised.     

京津冀生态涵养区生态与产业协调发展影响因素分析

[目的]京津冀协同发展国家重大战略将冀北地区的发展确定为承担生态保障与水源涵养功能,文章基于长期以来该区域生态脆弱、经济落后的特征,研究了该生态涵养区生态与产业协调发展的影响因素,目的是为该区域生态建设与产业经济协调发展提供参考。[方法]设置了影响生态建设与产业经济协调发展的规模因素、经济因素、社会因素与政策因素四大类37个影响因素,借助于统计数据,在对数据进行标准化处理的基础上,应用计量经济模型,通过因子分析法将各个因素进行分类归纳为5个公因子,利用SPSS软件回归模拟结果显示各个因素对生态建设与产业经济协调发展的影响作用。[结果]将四大类通过因子分析法的主成分分析,应用计量经济模型模拟,拟合优度较高,影响因素通过分组具有较强的解释力,结果能够很好地反映这些影响因素对生态建设与产业经济协调发展的影响方向与影响程度。[结论]依据定性分析假设与计量模拟分析结果,针对存在的问题与发展机遇,提出对策建议:继续加强生态建设项目的推进、适度扩大产业经营规模、加大生态建设与产业发展投资力度、实施资源节约型生产创新模式以及健全和完善生态与经济协调发展制度。     

中华人民共和国成立70年来生态文明体制变迁的内在逻辑与实践启示

中华人民共和国成立以来,中国共产党带领中国人民不断探索实践生态文明建设。随着人民环境偏好的增强,中国的生态文明体制不断变迁以满足人民日益增长的美好生态环境需要。通过对中国环境管理机构、环境保护政策变迁历程的梳理,可以探析其变迁的内在逻辑和动力机制。中国的生态文明体制变迁始终坚持以人民为中心的发展思想,以适应人民群众环境偏好变化为逻辑起点,并不断通过体制改革来提高环境治理效率和改善环境治理效果。中华人民共和国成立以来生态文明体制的变迁为新时代生态文明建设奠定了基础、指明了方向,在未来建设美丽中国过程中要坚持以人民为中心的发展思想以满足人民环境偏好变化、完善生态文明制度建设为增强环境治理的效果和效率提供保障、以综合治理的思路构建中国特色社会主义生态文明建设的治理体系。     

Evaluating museum visitor experiences based on user-generated travel photos

ABSTRACT

This research introduces online travel photos published on social media platforms as a complementary data resource to examine the behavior and experience of museum visitors. The practical value of online travel photos is demonstrated through a case study of popular Hong Kong museums, particularly by using the photo content and metadata available from the Flickr platform. The proposed approach is a generic method for understanding museum visitor behavior and preferences, and supports museum practitioners in developing improved products for visitors. The case study findings are particularly beneficial for tourism managers, especially those in Hong Kong, in promoting and attracting tourists to visit local museums.     

系统性金融风险的历史考察与防范对策

深入学习习近平在中国共产党第十九次全国代表大会上的报告，在考察20世纪以来的12次金融危机的基础上，对系统性金融风险发生的根源进行了研究，并结合我国当前系统性金融风险面临的形势，提出了防范系统性金融风险的对策建议。研究表明，将过去100多年引发金融危机的系统性金融风险的根源与我国当前的金融形势进行比较分析，可以发现我国面临的系统性金融风险形势十分严峻，必须在党的领导下，采取打击金融腐败、适当收紧货币政策、完善金融监管体系、维护币值稳定、加强金融科技监管等相关政策来防止系统金融风险的发生。     

浅谈基于大数据背景下的数字经济发展——以数字电网为例

我们已经进入了一个全新的大数据信息化时代,充满了更多的机遇与挑战。大数据及数字经济的出现极大程度地改变了传统技术及工作思维的方式。数字经济是继工业和农业之后的又一大经济形态,为社会的经济增长提供了新的动力。通过分析电网行业传统的科学技术及作业方式,论文简要阐述了基于大数据信息化发展下电网的影响,并认为信息化技术的发展对于数字经济有着至关重要的影响及重要性。最后论文讨论了数字经济发展存在的问题及方向。     

区域森林公园生态效率实证分析——以华东地区为例

采用Malmquist-Luenberger指数法对华东地区森林公园生态效率值进行测定的结果表明:从时序范围看,2011—2016年华东地区森林公园生态效率的均值为1. 006,但从2015年起进入下滑态势,说明华东地区森林公园的生态效率已经达到有效水平,但在扩大森林公园规模的同时忽视了对环境的有效保护以及资源的合理配置;从空间差异角度看,只有浙江与安徽两省的森林公园生态效率值未达到有效水平(分别为0. 851和0. 871),其余各省(市)的森林公园生态效率值均大于1,说明区域内存在一定的差异性;技术进步指数下降是制约MalmquistLuenberger指数提升的主要原因。由此可见,加大技术投入,促成交流合作机制,形成特有的竞争优势等,对提高区域森林公园生态效率是十分重要的。     

Estimating yield curves of the U.S. Treasury securities: An interpolation approach

Following the approach of interpolation, this paper proposes the multiple exponential decay model to fit yield curves for both the U.S. TIPS market and the conventional Treasury security market. Several estimation methods, including the unconstrained/constrained nonlinear minimization, quadratic programming, and the iterative linear least squares, are applied to estimate the unknown parameters according to different curve‐fitting purposes. Comparisons between the proposed model and the alternatives show that the multiple exponential decay successfully (1) adapts to a variety of shapes associated with yield curves, (2) (partially) keeps in line with the economic interpretations of Nelson–Siegel summarized by Diebold and Li ( 2006 ), and (3) dominates the competing models in curve‐fitting performance measured by mean fitted‐price errors over the sample period. In addition, the exact specification of a nonparametric interpolation model is pinned down by applying three statistical tools, which enable us to jointly take into account validity, optimality, and parsimoniousness of the proposed model.     

可食性小麦蛋白膜的研究

本文介绍了小麦蛋白及其成膜特性,总结了国内外可食性蛋白膜的研究现状,提出了可食性小麦蛋白膜的研究方案,并对膜的安全性及其应用作了展望。     

现代网络安全技术分析

随着网络技术的广泛应用，网络安全也越来越受到重视。本简述了网络安全问题的定义和TCP／IP协议的安全漏洞。同时，介绍了当前网络采用的安全技术。