阵列处理器中改进几乎空白子帧算法的并行化实现

两层异构网络中出现的小区间干扰协调是当前异构网络干扰问题研究的热点。针对软件实现增强小区调度几乎空白子帧(ABS)的干扰方案存在处理数据量大、速度慢的缺点,基于可重构阵列结构提出了一种动态ABS干扰协调的并行化硬件实现方案。该算法在增强小区内根据用户数动态分配ABS比例,以改善小区边缘用户的信道容量,通过流水线的方式使用多个轻核处理元(PE)实现并行计算以提高运算效率。测试结果表明,使用12个PE同时调度实现算法的映射,运行1 983个周期,其性能比单个PE提升77.03%,该算法的并行计算能力得到显著提升,宏基站用户的吞吐量可以达到4.76 Mbit/s。     

民用飞机适航安全性数据追溯性分析与建模

民用飞机适航安全性数据间的追溯性是审定过程中判定系统安全性工作完整性和准确性的重要方法,但随着民用机载产品安全关键特性及机载设备的综合化程度不断提高,相关数据间追溯关系的复杂性也大大增加,给适航安全性审定工作带来较大挑战。为建立安全性数据及其关联性的评价标准及验证方法,从安全性需求确认及验证、分析方法,以及相关运行维护分析等方面总结审定要素和评审要求,提出了一种整合设计数据、安全性数据与运行维护数据的安全性数据追溯模型。通过该模型在型号工作中的具体应用及情况分析,表明其可为我国民机型号安全性评估及审定工作提供理论支撑。     

How do firms finance their exports? – evidence from China

Using a firm-level production data over the period of 2005–2009 from China, this paper provides a new empirical evidence on how firms finance their exports when they have several financial options. The main results of the paper can be summarized as follows. First, firms who have better access to any finance are more likely to export and export more. More financial options lead to a higher export probability and capacity due to the complementary relation between financial options. Second, of all financial options, the internal finance captured by cash holdings or profit plays the most important role on firms’ export likelihood and volume. Firms rely more on the external finance through borrowing to start exporting, but depend more on issuing stocks to their shareholders to expand their exports. Third, subsample results suggest that the financial option of issuing stocks is generally more important for firms who have worse access to external finance in determining export propensity and quantity, such as private-owned firms, small-scale firms, young firms, and non-eastern firms.     

Where at home do exporters produce and export?

Foreign growth can induce changes in production structures across domestic regions through international trade. With a two‐country model with the explicit incorporation of two regions in the home country, we show that effects of foreign growth on exports and production to be possibly asymmetric among home regions. This foreign‐growth effect is especially prominent in Asia with China emerging as the largest trading country. We empirically test our theoretical hypothesis with the data set of Japanese regions. We find evidence that the growth of Asian countries leads to a change in the regional structure of exports and production in Japan. With respect to an adjacent Asian country, the growth of a foreign country exerts opposite effects on production among Japanese regions.     

民机CNS系统动态重构技术

动态重构是一项充分利用软硬件资源的技术。在介绍民机CNS系统和动态重构基本原理基础上,给出了一种动态重构的通用功能模块的设计方案,描述了利用有限状态机和排列组合原理计算系统配置的方法,并根据系统资源状况和应用的优先级对资源进行初次分配及再分配,设计出了一种动态重构算法,该算法能很好地兼顾资源备份式重构和资源抢占式重构。同时,指出对动态重构的品质设计需从可用性、可靠性、维护性方面考虑。最后,使用Simulink对动态重构算法的正确性进行了仿真验证。     

多数据源数据信息交换中间件的设计与实现

网络环境下的异构数据交换技术是数据集成、电子商务应用和Web服务合成系统等实际应用的核心支撑技术。文章基于"协作者"模式,以关系数据库和XML文档为异构数据源的典型代表,给出了Web服务环境下的数据交换模型,介绍了数据交换模型的4种基本操作的算法思想和利用Web服务合成技术实现数据交换的方法,通过一个示例,验证了文章提出的数据交换方法的有效性。     

网络效应、市场结构及技术进步——基于异质性偏好视角的分析

技术进步包括技术创新和技术更新,基于异质性偏好视角的网络效应下技术创新模型仅仅对比了仅有旧技术及新旧技术并存这两种状态,只是研究了技术创新,而尚未包括从新旧技术并存转为仅有新技术这一技术更新过程。基于异质性偏好的视角,本文考察了网络效应下消费者和厂商在技术创新、技术更新两阶段中的技术选择,在此基础上研究了竞争对于技术创新及技术更新的作用,并针对中国邮电通信业进行了实证分析。基本的结论在于,异质性偏好和网络效应共存条件下竞争能够增强技术创新、技术更新的动力,有助于技术进步,而相应的实证分析也证明了这一点。     

Aircraft safety analysis using clustering algorithms

In recent years, there have been many cost-benefit studies on aviation safety, which deal mainly with economic issues, omitting some strictly technical aspects. This study compares aircraft accidents in relation to the characteristics of the aircraft, environmental conditions, route, and traffic type. The study was conducted using a database of over 1500 aircraft accidents worldwide, occurring between 1985 and 2010. The data were processed and then aggregated into groups, using cluster analysis based on an algorithm of partition binary ‘Hard c means.’ For each cluster, the ‘cluster representative’ accident was identified as the average of all the different characteristics of the accident. Moreover, a ‘hazard index’ was defined for each cluster (according to annual movements); using this index, it was possible to establish the dangerousness of each ‘cluster’ in terms of aviation accidents. Obtained results allowed the construction of an easy-to-use predictive model for accidents using multivariate analysis.     

基于极化电磁波的飞行器姿态角估计新方法

提出使用单矢量传感器进行飞行器姿态角估计的新方法,安装在飞行器平台的单电磁 矢量传感器接收来自基站的极化电磁波信号,用MUSIC算法进行信号DOA和极化参数估计,得 到机体坐标系到地理坐标系的转换矩阵即飞行器姿态矩阵,最终估计飞行器姿态角。Matlab 仿真验证了该方法的有效性,姿态角估计误差在15°内,满足飞行器控制的要求。     

FDI技术溢出效应对我国制造业碳排放异质性影响研究

本文将我国制造业内外资企业在全要素生产率分解项下的差距,作为衡量FDI 技术溢出 效应影响内资企业技术进步水平的代理变量,使用GMM 方法分析了FDI 技术溢出效应对于我国 制造业CO2 增速的影响。结果表明受我国制造业异质性的影响,在不同行业分类中FDI 技术溢出 效应对于内资企业全要素生产率分解项的影响存在较大差异,相应的对于我国制造业CO2 增速的 影响也存在差异,为此本文针对我国异质性制造业特征,提出了如何吸收FDI 技术溢出效应以提 升内资企业全要素生产率水平,进而降低CO2 增速的政策建议。