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.     

Do special issues offer something special? An overview of research trends in Telecommunications Policy special issues

This study explores the value of special issues by analyzing the characteristics of special issues of Telecommunications Policy (TP). Specifically, this study examines the status of special issue publications, the characteristics of their articles compared with those of general issues, and the factors affecting article citations. For the analysis, all information on TP articles published from 1976 to 2018 was collected from the Scopus database. A comparative analysis as well as a negative binomial regression were conducted on papers published after 1994, when the first special issue was published. The results show that special issues are distinguished from general issues by various characteristics, such as multinational author collaboration, number of references, keywords, and funding. While general issue papers are more frequently cited in academia, special issue papers show better performance in terms of online captures and social media sharing. Moreover, the smaller number of variables affects the frequency of citations in the case of special issues, revealing that content and format are more influential than author factors.     

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.     

Easing the assessment of emerging technologies in technology observatories. Findings about patterns of dissemination of emerging technologies on the internet

This paper considers the Web as a big data container that can be used by Technology Observatories and administrations to track emerging issues and more specifically emerging technologies. It considers information that is available on the Internet for free from different sources, and proposes a framework that can be useful to characterise them and to detect patterns of dissemination. This framework is made up of 30 metrics obtained from different kinds of sources (general web, patents, scholars?…). Some of them are obtained directly as the number of hits retrieved by queries on a search engine, and other ones calculated by means of ratios. This paper contains the development of a complete case that utilises this framework to characterise emerging technologies included in the well-known Hype Cycle for Emerging Technologies, in this case the 2015 release¹ and to analyze patterns of dissemination of these technologies on the Internet.     

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。     

Debt Issue Costs and Issue Characteristics in the Market for U.S. Dollar Denominated International Bonds

This paper analyzes the issue costs and initial pricing of bonds in the international market. In particular, we investigate the determinants of three components of issue costs: underwriter fee, underwriter spread (the difference between the offering price and the guaranteed price to the issuer), and underpricing (the difference between the market price and the offering price). Total underwriter compensation increases with the bonds' credit risk and maturity, but it is insignificantly related to issue size. Interestingly, underwriters appear to price some issue characteristics directly (by adjusting the fee) and other characteristics indirectly (by setting the guaranteed price). The two compensation components (fee and spread) are negatively related to each other. We provide evidence that this trade-off is consistent with income tax considerations, as well as with two-tier pricing by underwriters. We find no evidence of underpricing.     

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。     

银行保函在业主反索赔中重要作用的探讨

我国建筑业目前正处于加入WTO后的3～5年的过渡期，国内建筑市场国际化的趋势使工程索赔问题必须与国际惯例接轨，从国际工程惯例出发，详细论述了银行保函的种类及其在业主反索赔过程中的重要作用，为业主提供了一种可以借鉴的工程项目管理方式。     

我国外汇储备：安全性、成本风险及对策

我国外汇储备狭义上的安全性，即外汇储备资产本身的安全令人担忧。我国已经为高额的外汇储备付出巨大成本和承担了很高的风险，同时，高额外汇储备也对我国经济发展产生了一系列负面影响和风险。从这个意义上来看，我国外汇储备的现状已成为威胁金融安全的一个重要隐患。因此，我国外汇储备政策的调整已经刻不容缓。     

宝钢武钢“整体上市”异同探究

宝钢集团于2004年8月12日推出增发方案后股价大跌,与2003年11月18日武钢增发方案推出时的市场表现大相径庭。两者整体上市模式基本相同,为何反差如此之大?本文试图从其“增发方案是否存在让利”,“融资量是否为市场所容纳”,“拟收购资产是否高质量”三个方面找出其原因所在,也为当前欣欣然的“整体上市”热潮敲一下警钟。