关于轻柴油使用的问题讨论

根据轻柴油使用中存在的问题，对轻柴油的测定、使用和质量标准提出了改进建议。     

中国共产党工业化道路理论的学理性探析

中国的工业化取得了举世瞩目的成功。理论是行动的指南,中国共产党提出的工业化理论为制定工业化战略和政策指明了方向。本文聚焦中国共产党工业化道路理论,从思想脉络和发展规律角度探求该理论的动态演进和深层机理,以期推进对中国共产党工业化理论的系统性、科学性和学理性研究。本文梳理和归纳了中国共产党农轻重协调发展理论(工农业关系论与农轻重次序论)和工业化发展战略理论(重工业优先发展论、农村工业化论、新型工业化论、"四化"同步发展论)的主要观点和历史演进,并剖析了每个理论观点背后的主要依据。本文认为,中国共产党工业化道路理论的演进过程是一个内涵不断丰富和深化的过程,是一个把马克思主义基本原理同中国伟大实践密切结合的过程,也是一个工业化驱动理论引领工业化道路理论的过程。     

Urban wireless traffic evolution: The role of new devices and the effect of policy

The emergence of new wireless technologies, such as the Internet of Things, allows digitalizing new and diverse urban activities. Thus, wireless traffic grows in volume and complexity, making prediction, investment planning, and regulation increasingly difficult. This article characterizes urban wireless traffic evolution, supporting operators to drive mobile network evolution and policymakers to increase national and local competitiveness. We propose a holistic method that widens previous research scope, including new devices and the effect of policy from multiple government levels. We provide an analytical formulation that combines existing complementary methods on traffic evolution research and diverse data sources. Results for a centric area of Helsinki during 2020–2030 indicate that daily volumes increase, albeit a surprisingly large part of the traffic continues to be generated by smartphones. Machine traffic gains importance, driven by surveillance video cameras and connected cars. While camera traffic is sensitive to law enforcement policies and data regulation, car traffic is less affected by transport electrification policy. High-priority traffic remains small, even under encouraging autonomous vehicle policies. Based on peak hour results, we suggest that 5G small cells might be needed around 2025, albeit the utilization of novel radio technology and additional mid-band spectrum could delay this need until 2029. We argue that mobile network operators inevitably need to cooperate in constructing a single, shared small cell network to mitigate the high deployment costs of massively deploying small cells. We also provide guidance to local and national policymakers for IoT-enabled competitive gains via the mitigation of five bottlenecks. For example, local monopolies for mmWave connectivity should be facilitated on space-limited urban furniture or risk an eventual capacity crunch, slowing down digitalization.     

Testing the predictive accuracy of COVID-19 forecasts

We test the predictive accuracy of forecasts of the number of COVID-19 fatalities produced by several forecasting teams and collected by the United States Centers for Disease Control and Prevention for the epidemic in the United States. We find three main results. First, at the short horizon (1 week ahead) no forecasting team outperforms a simple time-series benchmark. Second, at longer horizons (3 and 4 week ahead) forecasters are more successful and sometimes outperform the benchmark. Third, one of the best performing forecasts is the Ensemble forecast, that combines all available predictions using uniform weights. In view of these results, collecting a wide range of forecasts and combining them in an ensemble forecast may be a superior approach for health authorities, rather than relying on a small number of forecasts.     

Capital requirements and claims recovery: A new perspective on solvency regulation

Protection of creditors is a key objective of financial regulation. Where the protection needs are high, that is, in banking and insurance, regulatory solvency requirements are an instrument to prevent that creditors incur losses on their claims. The current regulatory requirements based on value at risk (V@R) and average value at risk (AV@R) limit the probability of default of financial institutions, but they fail to control the size of recovery on creditors' claims in the case of default. We resolve this failure by developing a novel risk measure, recovery V@R. Our conceptual approach is flexible and allows the construction of general recovery risk measures for various risk management purposes. We provide detailed case studies and applications. We show that recovery risk measures can be used for performance-based management of business divisions of firms and discuss how to calibrate recovery risk measures to historical regulatory standards. Finally, we analyze how recovery risk measures react to the joint distributions of assets and liabilities on firms' balance sheets and compare the corresponding capital requirements with the current regulatory benchmarks based on V@R and AV@R.     

The North Korean economy seen by satellite: Estimates of national performance,regional gaps based on nighttime light

External estimates must be used to assess North Korea’s economy because Pyongyang authorities withhold economic statistics. The Bank of Korea’s figures are considered the most widely employed estimates. However, they have several limitations. This paper estimates North Korea’s economic growth over a more than 20-year period, by analyzing the nighttime lighting, as recorded by orbiting satellites. The data is more objective and reliable than other data used to evaluate the North Korean economy. It indicates steady growth after 2000, contradicting Bank of Korea estimates. The methodology also has the advantage of being able to gauge regional economic activity. Performance varied widely among regions, the result of internal factors such as market activities and external factors such as trade with China and economic cooperation with South Korea.     

一种高负载自重比轻型机械臂的研究

针对现有轻型机械臂负载自重比较小的问题,提出了将微型液压系统作为轻型机械臂直接驱动源的方案。设计了液压驱动轻型机械臂的机械结构,利用Arduino平台搭建了控制系统,提出了控制方法,并进行了实验。实验结果表明:应用微型直驱式液压系统的轻型机械臂负载自重比高,定位准确。     

Pandemics and cash

We investigate the relationship between firms’ cash holdings and pandemics. Our results show that compared to tele-workable firms, whose employees can work remotely, non-tele-workable firms with more on-site employees increase cash during pandemics. This increase in cash comes from short-debt, preferred stocks, reduction in capital expenditures, discontinuation of some operations and lower tax payments. Firms hold more cash as a reaction to higher default risk. For non-tele-workable firms, there is a positive relationship between abnormal stock returns and cash, suggesting that this increase in cash during pandemics is not driven by behavioral reasons but by increases in uncertainty in labor productivity.     

Redevelopment along arterial streets: The effects of light rail on land use change

We use difference-in-differences approaches and parcel-level data from Minneapolis to estimate the effects of light rail on land use change using alternate definitions of treatment area. Results using circular buffers corroborate previous findings that light rail has virtually no effect on land use change in our study area. In contrast, light rail increases the likelihood of land use change along arterial streets that cross the line at station areas. To accurately model the effects of public transit projects on urban land use, one must consider how potential riders access station areas, rather than assuming accessibility improves radially around a station.     

万科集团资本结构问题探讨

改革开放以来,我国经济迅猛发展,特别是房地产行业对经济增长和投资增长的贡献较大,在我国经济发展史上扮演着不可或缺的角色。对于房地产企业而言,资本结构在企业运营中发挥着重要作用,已逐渐成为财务研究领域的热点。论文将万科股份有限公司作为研究对象,首先简要介绍企业的基本情况,其次通过数据分析其资本结构,发现存在的问题,最后提出针对性建议,以期在一定程度上为万科集团发展助力,促进行业整体的可持续健康发展。