GPS/GLONASS同步的可编程逻辑实现

给出了一种用于第三代移动通信系统(3G)CDMA2000基站的时钟同步方案。由一个双星接收卡接收GPS/GLONASS标准秒信号作为整个时钟同步系统的参考,分两级锁相环实现:第一级锁相环采用软件锁相,输出10MHz信号作为第二级锁相环的参考源,第二级锁相环为2个模拟锁相环,分别输出16fc和48fc(fc=1.2288MHz)。2S信号由16fc分频得到。这种设计保证了输出时钟的长期稳定性和短期稳定性,满足协议所规定的同步精度。详细介绍了数字鉴相器、2S产生电路、相差检测及控制电路的电路设计和有关仿真结果。     

Farms,farmworkers and new forms of livelihoods in southern Africa

This review essay looks at three recent books on farms, farm labour, and rural livelihoods in southern Africa. The books—Farm labor struggles in Zimbabwe: The ground of politics, by Blair Rutherford; Ordered estates: Welfare, power and maternalism on Zimbabwe's (once white) Highveld, by Andrew M. C. Hartnack; and Zimbabwe's migrants and South Africa's border farms: The roots of impermanence, by Maxim Bolt—offer a range of insights into labour politics and management, new forms of livelihoods on farms and former farms, and how those living on farms interact with informal economies. Usefully, the books cover events over the past two decades, as well as providing regional insights into important contemporary issues. While the books converge in a number of ways, this essay will focus on two key themes: (i) how they address issues of farm management and labour control; and (ii) they ways in which they explore farmworker agency in times of change and in areas of informality and precarity.     

一种适用于多相相干解调的载波同步方法

本文介绍了一种新的载波同步方法,并将它用于对载波前导的快速精确同步。文章给出了同步算法的仿真流程和部分仿真结果,并对其应用前景作了简单讨论。     

中国速生丰产林发展状况研究

从速生丰产林工程发展阶段出发,论述了现阶段速生丰产林的特点和存在问题,具体分析了制约速生丰产林发展的政策和管理方面的原因,并从政策、产业发展、外部环境、生产布局、产权等不同角度,提出了实现速生丰产林快速发展的措施对策和政策支持。     

制度变迁同步化对中国对外直接投资的影响

本文使用2006~2016年中国对78个国家的OFDI数据,实证检验了制度变迁同步化水平对OFDI的影响。结果显示:首先,双边制度变迁同步化水平显著提升中国OFDI规模,分别体现在政治制度和经济制度中;其次,中国与发展中国家的政治制度和经济制度变迁同步化均对OFDI具有显著推进效应,与发达国家的制度变迁同步化的OFDI效应则更大程度上与经济制度相关;再次,母国和东道国制度变迁同步化水平构成中国OFDI的“推动力”与“吸引力”;最后,多样化的OFDI动机与不同维度下的制度变迁同步化密切相关。可见,国家制度变迁的整体效率以及不同维度间的制度配置效率是推进以OFDI为载体的中国国际化战略的关键。     

Information interaction,behavioral synchronization and asset market volatility

This paper focuses on the synchronization of trading behavior caused by interactions among traders. The study begins with an agent-based model in which most agents make investment decisions based on three types of information (neighbor, public and private information) according to their heterogeneous personal preferences. Considering the influence of the social relationship network in reality, traders in our model are connected by a complex network. We use four different types of networks. The simulated results of this model reproduce several stylized facts about the asset market. Simulated results show that when preference of traders for neighbor information increases, the level of trust among traders will gradually increase and then there will be a “leap” at a certain point. The mutual trust among traders is achieved through coupling effect in the network. Moreover, with the frequent synchronization of traders’ behavior, extreme phenomena in financial markets will emerge. In addition, our numerical simulations show that when the average degree of network is higher, behavioral synchronization will emerge at a lower level of dependence on neighbor information. The degree distribution of the network will also have a significant influence on the convergence processes of behavioral synchronization. The more heterogeneous the degree distribution is, the easier the behavioral synchronization process will occur. In our simulations, the mode of agent behavior expectation will also enhance the effect of network structure to behavioral synchronization. Finally, this paper affirms the important role of public information and learning mechanism (expectation formation mode) in the process of behavioral synchronization.     

Is there any evidence of tax-and-spend,spend-and-tax or fiscal synchronization from panel of Indian state?

We examine the government revenue and government expenditure nexus using a panel of 26 Indian states from 1980–1981 to 2014–2015. While most of the previous literature claims that revenue and expenditure series are non-stationary at level, we employ both Narayan and Popp two structural break and cross-sectional augmented Im-Pesaran-Shin (CIPS) panel unit root tests, and found two series are stationary. Further, our results derived from Dumitrescu–Hurlin panel causality test support the ‘fiscal synchronization’ hypothesis for Indian states. Finally, the revenue and expenditure of Indian state governments are segregated into revenue account and capital account, and again our results support the existence of ‘fiscal synchronization’ hypothesis.     

The feasibility of currency union in Gulf Cooperation Council countries: A business cycle synchronisation view

This paper study the feasibility of a monetary union among Gulf Cooperation Council (GCC) countries, by measuring the evolution of economic integration among them. Considering the critical role of crisis and shocks in the integration process within the region, we determine whether GCC countries are characterised by a common business cycle. We suggest a different empirical approach that, unlike previous studies, allows one to endogenously detect structural changes in the comovement process between outputs. We apply a new measure for this region that is based on the time‐varying coherence function. Such a measure not only detects comovement dynamics but also distinguishes these dynamics in terms of short‐ and long‐term cycles. Additionally, we can test whether certain countries tend to be more synchronised. The main finding of this study is that not all GCC countries share a common short‐term business cycle. However, in the long term, all country‐pairs indicate a medium‐level synchronisation in the most recent subperiods. The new role of the United Arab Emirates’ regional trade platform allows it to strengthen long‐term business cycle comovement, thus differentiating it from other GCC country‐pairs that have shown a decline in the last two subperiods.     

新型城镇化视角下武汉城市圈城镇化质量研究

城市群作为我国当前城镇化发展的主体单元,细化研究尺度对因地制宜制定和实施区域协同发展规划具有更科学的指导意义。本文基于对新型城镇化内涵的理解,从城镇建设水平、城镇化推进效率、包容性和可持续性维度构建新型城镇化质量评价体系,基于熵值法,从县域尺度对武汉城市圈城镇化质量进行评价。结果表明:第一,武汉城市圈城镇化质量整体偏低,各维度发展不平衡;第二,城镇化质量表现出武汉市"一城独大"的特征,中心城市辐射带动作用不强,区域差距大;第三,城镇化率与城镇化质量表现出较好的同步性,但半数以上的县域城市处于"低城镇化率-低城镇化质量"阶段,同步性高但发展水平低是现阶段武汉城市圈城镇化的主要特征。     

Macroeconomic imbalances and business cycle synchronization. Why common economic governance is imperative for the Eurozone

This paper investigates a new category of influential factors on business cycle synchronization (BCS), so far hardly regarded in the BCS literature. It provides an empirical assessment of the impact of macroeconomic imbalances, as monitored by the European Commission by the scoreboard indicators since 2011, on BCS in the Euozone. We use a quarterly data set covering the period 2002–2012 and estimate the direct and indirect effects of macroeconomic imbalances in the pre- and post-crisis period in a simultaneous equations model. Business cycle correlation between EA members is measured by the recently proposed dynamic conditional correlation of Engle (2002) which can better identify synchronous and asynchronous behaviour of BC than the commonly used measures. We find that appearing differences between EA members in current account, in government deficit and public debt, in private debt and unit labor cost developments have reduced BCS in the EA, even more in the post-crisis period than before. Moreover, these explanatory factors of BCS, generally reinforce each other and are also influenced by other critical macro imbalances. Since BCS is essential in a monetary union, this paper provides clear support that a stronger, common economic governance would be important for the functioning and survival of the Eurozone.