基于快速OPAST算法的直扩信号PN码序列估计

在直接序列扩频（DSSS）通信对抗系统中，伪码（PN）序列估计是一个重要的研究课题。针对在某些情况下权值向量不收敛的问题，提出了一种基于快速正交投影逼近子空间跟踪（OPAST）算法和滑动窗技术的直扩信号PN码序列估计算法，对非同步接收DSSS信号按照宽窗口分段，利用快速OPAST算法提取主特征向量，滑动窗技术实现码同步。该算法迭代权值向量具有正交性以及良好的收敛性，同时解决了常见相位模糊问题。算法具有较低复杂度，数据存储量少，易于硬件实现与实时处理。仿真结果表明，在-10 dB的较低信噪比背景环境中，该快速OPAST算法可以正确有效地估计出PN码序列。     

Do rival political parties enforce government efficiency? Evidence from Canada 1867–2021

This paper investigates the role of inter-party rivalry in enhancing federal government efficiency in post-Confederation Canada. It tests and finds confirmation in the data for two hypotheses. The first is that the ex post size of the first versus second seat share margin is a useful metric for the ineffectiveness of political parties in policing the incumbent's spending behaviour over its period of tenure. The second is the hypothesis that shirking by the incumbent governing party is decreased by greater expected electoral contestability and expected contestability is related to the effective number of competing parties (ENPSeats) nonmonotonically. In this regard the results suggest that contestability in Canada reaches a maximum when the incumbent faces a value of ENPSeats that is closer to 2.5 than Duverger's 2.     

A multi-stage stochastic programming approach for pre-positioning of relief supplies considering returns

A dynamic pre-positioning problem is proposed to efficiently respond to victims’ need for relief supplies under uncertain and dynamic demand in humanitarian relief. The problem is formulated as a multi-stage stochastic programming model that considers pre-positioning with the dynamic procurement and return decisions about relief supplies over a time horizon. To validate the advantages of dynamic pre-positioning, three additional pre-positioning strategies are presented: pre-positioning with one-time procurement and without returns, pre-positioning with one-time procurement and returns, and pre-positioning with dynamic procurement and without returns. Using data from real-world disasters in the United States in the Emergency Events Database, we present a numerical analysis to study the applicability of the proposed models. We develop a sample average approximation approach to solving the proposed model in large-scale cases. Our main contribution is that we integrate dynamic procurement and return strategies into pre-positioning to decrease both costs and shortage risks in uncertain and dynamic contexts. The results illustrate that dynamic pre-positioning outperforms the other three strategies in cost savings. It also indicates that a higher return price is particularly helpful for decreasing unmet demand. The proposed models can help relief agencies evaluate and choose the solutions that will have the greatest overall effectiveness in the context of different relief practices.     

基于CDIO模型的一流专业混合式教学模式研究与实践——以“物流学”为例

针对一流本科专业的学生能力培养目标,结合CDIO教育管理理念,提出了“线上平台和线下课堂”的混合式教学实施方法,并以“物流学”为例阐述具体改革内容。混合式教学促使教学闭环管理过程更为可行和有效,对教师教学水平提升和学科一流专业建设具有重要意义。     

Formula feeding: Evidence for health,nutrition and early childhood development during the critical first 1000 days from rural China

Infant and young child feeding is crucial to physical and mental development and long-term health. In developing settings, the widespread use of formula raises concerns regarding the growth and development of infants. However, little is known about the role that formula may play in the observed poor infant health, nutrition and development in developing areas. Using a rich panel dataset of 1802 infants aged 6–30 months collected at six months intervals from rural China, we describe the prevalence of formula feeding, identify households that are more likely to use formula, and examine the associations between formula feeding with various dimensions of infant health, nutrition and development outcomes: anthropometric measurements, infant illnesses, cognitive, psychomotor, and socio-emotional development. We found infant formula is widely used in rural China, and it is significantly associated with infant health and nutritional outcomes - formula feeding is associated with a 4.59-point increase in Hemoglobin concentration and a 13% reduction in anemia prevalence, but is also associated with a 0.11-sd decrease in weight-for-age and height-for-age Z-scores. Moreover, infants are more likely to be fed formula when their families have higher socioeconomic status, when their parents have out-migrated, and when they have no siblings. Our findings suggest that there is a need to promote age-appropriate feeding practices, with an emphasis on families who are particularly in need of guidance, to reduce over-reliance on formula, and provide support for mothers to delay their migration or create pathways for rural parents to bring their children with them when they migrate.     

Credit risk pricing in a consumption-based equilibrium framework with incomplete accounting information

We present a consumption-based equilibrium framework for credit risk pricing based on the Epstein–Zin (EZ) preferences where the default time is modeled as the first hitting time of a default boundary and bond investors have imperfect/partial information about the firm value. The imperfect information is generated by the underlying observed state variables and a noisy observation process of the firm value. In addition, the consumption, the volatility, and the firm value process are modeled to follow affine diffusion processes. Using the EZ equilibrium solution as the pricing kernel, we provide an equivalent pricing measure to compute the prices of financial derivatives as discounted values of the future payoffs given the incomplete information. The price of a zero-coupon bond is represented in terms of the solutions of a stochastic partial differential equation (SPDE) and a deterministic PDE; the self-contained proofs are provided for both this representation and the well-posedness of the involved SPDE. Furthermore, this SPDE is numerically solved, which yields some insights into the relationship between the structure of the yield spreads and the model parameters.     

新文科背景下一流本科专业卓越人才培养模式改革——以安徽大学物流管理专业为例

介绍了安徽大学物流管理专业作为物流管理国家一流专业建设点在新文科建设下人才培养模式方面的改革,涉及学校、教师和学生三方参与主体,包括构建融合师资、加强课题教学、强化实践教育、注重联合培养的协同育人系统优化等,以期实现新内涵现代物流卓越人才培养目标,推进一流本科专业建设。