Dynamic Currency Linkages and Their Determinants: An Empirical Study for East Asian Economic Community Region

In this article, Copula GARCH models have been employed to study the inter-temporal process of currency market co-movements between ASEAN+6 countries (referred to in this study as East Asian Economic Community) and ASEAN+6 currency market index. Empirical results show that the sample countries of the region exhibit varying levels of currency co-movements with the Asian benchmark. Markov regime switching results show that many of the countries which had high dependences with the regional currency index as was found in copula estimations had also overlapping currency market cycles. Using Principal Component Analysis, we find that three statistical factors explain exchange rate co-movements which came out to be trade linkages, economic risk, and currency market openness in our dynamic panel data estimation.     

初相注入式快速符号同步的一种实现方法

通过平方滤波算法对时钟初相进行预估计,实现了Gardner算法下初相注入式符号同步.该方法具有快速、高精度的特点,尤其是较好地解决了初始点为过零点的极端情况下,Gardner算法收敛方向不确定、收敛时间较长的问题.计算机仿真和实际应用证实了该方法的有效性.     

飞行器部件低散射载体的分析与设计

降低弱散射源的雷达散射截面,增强飞行器部件的隐身性能至关重要。但部件脱离飞行器后,需依托载体才能得到准确的隐身性能。通过探究低散射载体设计机理和思路,考虑爬行波、行波、入射频率等影响因素,设计了一款低散射载体。通过理论建模、特征基函数法仿真计算和试验测试方法验证,所设计的低散射载体的雷达散射截面足够低,可有效消除弱散射源以外的其他杂波散射影响,还原部件真实状态,有利于提升弱散射源隐身性能评估的准确性,从而优化飞行器隐身设计。     

论高校校园文化建设与思想政治教育的融合

校园文化是一所学校的文化历史积淀,内涵丰富,外延广泛,形式多样。高校校园文化建设对于加强大学生思想政治教育、保证大学生健康成长具有重要影响。高校思想政治教育工作主导着校园文化建设的方向,校园文化建设是高校思想政治教育工作的有效载体,只有校园文化科学发展才能对大学生起到有效的思想政治教育,保证其健康成长。     

OFDM系统的多符号改进算法

针对OFDM训练符号同步算法中存在的大采样数据而导致捕获时间过长的问题。提出了一种多符号改进算法。该算法应用对多个符号等间隔取样并共轭相乘累加的方法，在采用小数目的采样数据时就可以取得较好的性能，同时缩短了定时捕获时间，克服了原来算法中存在的问题。最后，仿真表明该算法的有效性。     

大动态PCM/FM信号的载波频率同步

针对大动态脉冲编码-频率调制（PCM/FM）遥测信号的载波频率同步,提出了基于快速傅里叶变换（FFT）及频谱重心的载波频率估计方法,并采用了频谱叠加及频谱截取的优化方法提高算法估计精度。相对于其他基于FFT的频率估计算法,频谱重心法有着更高的估计精度及更好的抗噪声性能,而且复杂度代价很小。仿真的均方误差结果表明,基于FFT长度为2 048和2块叠加以及保留信号99.9%能量的频谱截取方案有最好的估计性能。在最大多普勒频率、多普勒一阶变化率及二阶变化率分别为0.5倍、0.3倍及0.2倍符号率的大动态条件下,基于频谱重心法的二阶锁频环能够较好地完成载波频率跟踪。误码率曲线表明,经过频偏校正后的多符号非相干解调（MSD)性能与无频偏情况相比,无性能损失。     

论隐性载体在高校思想政治教育中的发挥

新时期,隐性思想政治教育载体（以下简称隐性载体）由于其自身的优势,越来越广泛的应用于高校思想政治教育工作之中。隐性载体与显性载体相比,不仅覆盖面广,而且具有教育方式的多样性与隐蔽性、教育内容的丰富性与灵活性、教育效果持久性及教育过程无逆反性等优点。通过对隐性载体如校园环境、社会实践活动、心理咨询和社会公共环境等的应用现状的分析可知,要提高思想政治教育的实效性,需要进一步完善、优化现有隐性载体和开发新的隐性载体,进而使高校思想政治教育达到理想的教育效果。     

一种用于高速QPSK解调的四次方环载波恢复电路

为解决高速QPSK信号全数字解调的技术瓶颈问题,采用模拟方案 ,研制了一种四次方环载波恢复电路,重点介绍了应用混频器上变频特性的宽带平方电路以 及锁相环（PLL）载波提取电路的设计过程。测试结果表明,该载波恢复电路可以完成载频 为720 MHz、码速率100 Mbit/s～1 Gbit/s范围的QPSK信号同步载波恢复,解 决了高速信号相干解调中载波同步的关键技术问题。     

Reconciling Alternative Theories for the Safety of Owner–Operators

Motor carrier safety is an important concern of shippers, carriers, policy makers, consignees, insurance providers, and the motoring public. One aspect of carrier safety that has garnered substantial attention is whether carriers making greater use of owner–operators are more or less safe vis‐à‐vis carriers making greater use of employee drivers. Currently, conflicting theoretical predictions exist regarding the direction of this relationship. In this article, we offer a reconciliation of the alternative theoretical predictions by developing a coherent theory that merges sociological rational choice theory and theory regarding motor carrier safety. We subject our theory to empirical testing by fitting a series of seemingly unrelated regression models to a vector of safety measures tracked as part of the Federal Motor Carrier Safety Administration's Compliance, Safety, and Accountability program. Our results are consistent with our proposed theory of owner—operator safety and provide meaningful theoretical and managerial implications and directions for future research.     

Strategic Purity and Efficiency in the Motor Carrier Industry: A Multiyear Panel Investigation

Two questions facing motor carrier managers are (1) whether carriers should specialize in providing full truckload (TL) or less‐than‐truckload (LTL) services vis‐à‐vis offering mix of both and (2) whether this decision is contingent on carrier size. Yet, the literature provides little guidance because research to date has offered contradictory theoretical predictions and inconsistent empirical findings. Drawing on the theory of strategic purity and information processing theory, we explain why service specialization is likely to increase carriers' technical efficiency and why size will have a more pronounced effect on technical efficiency for carriers specializing in LTL services versus TL services. To test our theory, we assemble a panel data set from archival government sources regarding general freight motor carriers' provision of LTL and TL services. We measure carriers' technical efficiency using data envelopment analysis and test our hypotheses by fitting a series of panel data mixed‐effects models. Our results indicate that carriers are most technically efficient when they specialize in one service type. We also find that size positively affects technical efficiency but only for carriers specializing in LTL services; no returns to scale with regard to technical efficiency exist for carriers specializing in TL services.