Road safety determinants in low and middle income countries

The objective of this article is to summarize and review the literature on the determinants of road traffic injuries and fatalities, to identify the relevant research gaps in particular for low and middle income countries. We also present a cross-country analysis of the determinants of road traffic injuries and fatalities that take into account a wide range of potential environmental, economic and social factors. The present study focused on differences based on the level of development. The goal was to identify relevant commonalities that may assist in the creation of road safety policies common to countries at a similar level of development. The countries were divided according to the level of gross national income per capita, and these income-level groups were the primary units of interest. The results presented here focus on the differences by income level.     

基于AD9361的掌上型LTE RRU设计与开发

当前小体积远端射频单元（Remote Radio Unit,RRU）主要是皮站级别的Pico-RRU，其重量和体积仍然难以满足掌上型的要求。为此，采用高集成度的AD9361芯片来实现长期演进（Long Term Evolution，LTE）宽带收发信机功能，配合时钟同步模块、放大器模块和控制接口电路等一起构建低成本的掌上型RRU。主要解决了基于AD9516的时钟同步、低相位噪声设计和高灵敏度接收机设计三个技术难点，成功实现了掌上型、高性能、低成本的设计目标。整个RRU样机尺寸为18 cm×10 cm×2 cm，质量约500 g，量产成本千元以内。测试表明，该RRU下行误差向量幅度（Error Vector Magnitude，EVM）小于3%，优于3GPP要求的8%；10 MHz带宽时上行接收机灵敏度优于3GPP要求的-93.5 dBm。     

The development trinity: How regional integration impacts growth,inequality and poverty

Developing countries today have become more active participants in regional trade agreements. This raises questions about how the benefits of integration are distributed, and the extent to which lower‐income countries are able to capture development gains. Historically, such impacts have been difficult to identify with precision. This paper seeks to address this gap by empirically analysing the impact of regional integration on development, particularly the effects on growth and welfare. Using both bilateral and regional integration measures, we show that the ability to capture gains from integration varies across developing country regional groups, with developing Asia benefiting on par with developed countries. The findings in the paper indicate that trade and trade policy play an important role in reducing inequality and poverty in developing countries. It also shows that regionalism can function as a channel to make multilateralism a more adept way of addressing national challenges.     

环境公平感知、社会信任与农户低碳生产行为*——以农膜、秸秆处理为例

［目的］研究旨在探讨环境公平感知和社会信任与农户低碳生产行为之间的关系，为促进农户生产行为向低碳化方向转变提供对策建议。［方法］基于陕西和甘肃两省的村域调查数据，以农膜和秸秆处理为例，运用二元logistic模型探讨环境公平感知和社会信任对农户低碳生产行为的影响，并结合分层回归分析了社会信任在环境公平感知和农户低碳生产行为间的调节效应。［结果］（1）在环境公平感知维度中，人际公平感知正向影响农户的农膜和秸秆处理行为； （2）对社会信任来讲，人际信任对农户农膜和秸秆处理行为均有显著的促进作用，而制度信任仅对农户秸秆处理行为具有正向影响； （3）人际信任在种际公平感知和农户农膜处理行为之间具有显著的正向调节效应，而制度信任在两者之间具有显著的负向调节效应； 同样，人际信任在人际公平感知和农户秸秆处理行为之间具有正向调节效应，而制度信任弱化了人际公平感知对农户秸秆处理行为的影响。［结论］环境公平感知和社会信任是影响农户低碳生产行为的关键因素，且社会信任在种际公平感知和农户农膜处理行为之间以及在人际公平感知和农户秸秆处理行为之间具有显著的调节作用。     

Contradictions of the Climate-Friendly City: New Perspectives on Eco-Gentrification and Housing Justice

As local governments and corporations promote ‘climate friendliness’, and a low-carbon lifestyle becomes increasingly desirable, more middle- and upper-income urban residents are choosing to live near public transit, on bike- and pedestrian-friendly streets, and in higher-density mixed-use areas. This rejection of classical forms of suburbanization has, in part, increased property values in neighborhoods offering these amenities, displacing lower-income, often non-white, residents. Increased prevalence of creative and technology workers appears to accelerate this trend. We argue that a significant and understudied socio-environmental contradiction also occurs where the actual environmental outcomes of neighborhood transformation may not be what we expect. New research on greenhouse gas emissions shows that more affluent residents have much larger carbon footprints because of their consumption, even when reductions in transportation or building energy emissions are included. We describe an area in Seattle, Washington, the location of Amazon's headquarters, experiencing this contradiction and show a distinct convergence of city investments in low-carbon infrastructure, significant rises in housing prices and decreases in lower-income and non-white residents. We conclude with a discussion of a range of issues that require more attention by scholars interested in housing justice and/or urban sustainability.     

新型Ka频段宽角扫描圆极化相控阵天线

提出了一种新型的Ka频段圆极化相控阵天线。天线单元以单馈电开槽贴片天线为基础实现圆极化，通过微带贴片表面加载介质和辅助辐射器，展宽了天线波束宽度并优化了单元轴比。以该天线为阵列单元，采用顺序旋转布阵技术优化得到的2×2子阵，其辐射方向图具有良好的旋转对称性，由该子阵扩展形成的相控阵天线，有效地实现了圆极化宽角扫描特性。以8×8矩形阵列为例，仿真分析了此类二维相控阵天线波束扫描过程中的方向图和极化特性。研究结果表明，天线在工作频段内可实现方位360°、俯仰±60°扫描，扫描范围内天线增益波动和轴比均小于3 dB，同时该天线具有低剖面（高度尺寸为0.08λ0，λ0为空气介质波长）、结构简单、易于加工和集成等特点，非常适合小型化或一体化相控阵天线系统应用。     

基于联合分析法的城市住区绿地雨水设施 居民喜好度研究

城市化进程带来如城市内涝等诸多环境问题，使得 海绵城市和低影响开发成为热点。城市住区绿地作为城市绿地 的一个重要类型，既是住区居民重要的景观游憩场地，也是海 绵城市低影响开发的重要海绵体，是兼具径流绩效和景观绩效 等综合绩效的复合设施。如何让雨水设施在发挥径流绩效的同 时兼具满足居民需求的景观绩效，是目前相关研究的难点和热 点。居民喜好度的研究是住区绿地雨水设施景观绩效优化提升 的重要方法之一。通过联合分析法，遴选雨水收集、雨水转 输和雨水调蓄3个环节的源头减排雨水设施，模拟江南住区中 心绿地雨水设施场景收集居民评价，进行不同居民群体的设 施喜好度效用值相关性统计和住区绿地不同类型雨水设施效 用值及相对重要性分析。并通过走访、文献查阅解析所得数 据，为住区绿地雨水设施景观绩效提升和低影响开发设计提 供启示和借鉴。     

Stock market volatility forecasting: Do we need high-frequency data?

The general consensus in the volatility forecasting literature is that high-frequency volatility models outperform low-frequency volatility models. However, such a conclusion is reached when low-frequency volatility models are estimated from daily returns. Instead, we study this question considering daily, low-frequency volatility estimators based on open, high, low, and close daily prices. Our data sample consists of 18 stock market indices. We find that high-frequency volatility models tend to outperform low-frequency volatility models only for short-term forecasts. As the forecast horizon increases (up to one month), the difference in forecast accuracy becomes statistically indistinguishable for most market indices. To evaluate the practical implications of our results, we study a simple asset allocation problem. The results reveal that asset allocation based on high-frequency volatility model forecasts does not outperform asset allocation based on low-frequency volatility model forecasts.     

The impact of (un)conventional expansionary monetary policy on income inequality – lessons from Japan

ABSTRACT

This paper analyzes the impact of conventional and unconventional monetary policy on income inequality in Japan, using hitherto unexplored data from the Japan Household Panel Survey. Empirical evidence shows that expansionary monetary policy in Japan has contributed to diminishing the gender pay gap through an increase in working time of women relative to men, but also to increasing the education pay gap. These effects may have materialized via the aggregate demand channel and the labour productivity channel. In contrast, expansionary monetary policy has had no significant impact on the development of the age pay gap.     

公司为什么放弃债务的收益呢？

经典资本结构理论认为债务具有税盾效应和财务杠杆效应，因此公司会选择适当的负债以获得债务的税收收益。但是，现实中一些公司的负债很低，甚至为零。公司为什么放弃债务的税收收益呢？本文以2007～2011年中国A股上市公司为研究样本，从行为公司金融的视角分析管理者能力是否导致公司采用“低杠杆”策略。结果表明，中国上市公司存在普遍的低杠杆现象，管理者能力的差异是导致公司采用“低杠杆”策略的重要原因。