基于ELES模型的陕西城镇居民消费结构研究

消费是拉动经济发展的源动力,而研究消费的一个重要途径是对消费结构进行研究。消费结构不仅反映消费水平而且对于消费总量和产业结构有着重要影响。陕西城镇居民的消费结构经过了两个阶段的变化,由上世纪90年代中期以食品、衣蓠和家庭设备为主变化为以食品、医疗保健、交通通讯和教育文娱并重。同时,根据居民的消费弹性和消费结构的发展趋势,可以预见医疗保健和交通通讯等方面将成为居民未来的消费热点。     

预算法修订：权力与职责的划分

预算过程中的各行为主体的权责关系是预算法修订中的一项核心内容,而现行《预算法》在公众、人大、政府之间的权责方面尚存在一些问题。在分析了预算权职的基本逻辑、预算法宗旨及预算范围后,本文对在预算法修订中如何确定公民、人大代表、人民代表大会及政府部门的权力与职责提出了一些看法和建议。     

空基测控中继设备的相控阵天线设计

空基测控中继是为解决地面测控设备作用距离受视距限制的问题而提出的,而相控阵天线是空基测控中继设备的技术难点。根据实际需求,提出了相控阵天线的设计方案,对阵列形式、天线的流形、阵元间距、阵列规模以及阵元形式等进行了详细设计,并对天线的接收发射性能进行了仿真,对跟踪控制技术途径进行了阐述。所设计的相控阵天线增益可以满足约130 km、2 Mbit/s遥测数据中继,解决远距离低空飞行目标的靶场测控问题。     

压缩感知稀疏表示在雷达目标识别中的应用

高分辨距离像(HRRP)目标识别算法很多,在其利用高分辨距离像蕴含的目标结构信息的同时,也需要面对数据量巨大的难题。事实上,尽管高分辨距离像数据量巨大,但却是稀疏的,然而利用其稀疏特性进行识别的方法却不多。为此,提出了一种基于压缩感知稀疏表示方法实现目标识别的算法。该算法首先采用遗传正交匹配追踪（OMP）算法对一维距离像训练样本进行稀疏分解以获得类别字典,然后根据类别字典分析测试样本的重构误差实现目标识别。仿真实验证明,所提算法简捷、识别率更高,相较于常规算法识别率提高最多可达20%,并且在受到噪声干扰情况下依然能够稳健地识别目标。     

Are long-term return anomalies illusions?: Evidence from the spot Yen

This study investigates the sensitivity of the long-term return anomaly observed in the US$/Yen currency market to sample and method bias during the period from 11 October 1983 to 21 July 1999. Initially the CUSUM statistic is employed to identify subperiods of sign shifts in the mean returns. Then the dependence in these subperiods is investigated using the Hurst [Hurst, H.E., 1951. Trans. Am. Soc. Civil Eng. 116, 770–799] and the Lo [Lo, A.W., 1991. Econometrica 59 (5), 1279–1313] rescaled range statistics. The results suggest that rejection of the random null is conditional on both the procedure and the period being tested. The Hurst test may incorrectly lead to a rejection of the null hypothesis. However, the Lo test is a more appropriate approach to the data in this study. Thus previous research based on the Hurst test may have inadvertently introduced a method bias.     

Cross‐Functional Influence and the Supplier Selection Decision in Competitive Environments: Who Makes the Call?

This paper presents the results of a multiple‐case study that examines how procurement and engineering personnel share priorities, have a common vision, and influence the supplier selection decision in competitive environments of varying risk and uncertainty. We interviewed 113 procurement and engineering respondents from 26 different companies/business units across up‐, mid‐, and downstream segments of the oil and gas industry. Following a middle‐range theorizing approach, we develop a series of working propositions and theoretical frameworks, utilizing goal congruence theory to sharpen proposition development and create suggested extensions for theory. In general, we find that engineering personnel tend to dominate cross‐functional decision making in higher risk environments and that more equal arrangements exist when both risk and uncertainty are low. When competitive environment risk is low but uncertainty is high, considerable disagreement arises over which function “leads” this decision. Higher risk environments drive higher goal congruence through shared vision and consensus on who makes supplier selection decisions.     

测控通信系统资源重组的信号交换技术

测控通信系统的资源重组已在工程中逐步得到了认可与应用。要实现系统中各类资源的高效组合及有效利用，信号交换方式是直接影响资源重组规模与运行效能的关键环节。不同的交换方式直接关系到重组架构的形态，也决定了系统资源重组的范围、效率和能力。分析了不同信号交换形式的优劣，突出了基于IP协议的交换形式对于未来开放式资源重组系统的技术途径。所提出的设计思路可供测控通信系统实现全域资源重组借鉴及参考。     

Forecasting volatility with component conditional autoregressive range model

In this paper, we propose a component conditional autoregressive range (CCARR) model for forecasting volatility. The proposed CCARR model assumes that the price range comprises both a long-run (trend) component and a short-run (transitory) component, which has the capacity to capture the long memory property of volatility. The model is intuitive and convenient to implement by using the maximum likelihood estimation method. Empirical analysis using six stock market indices highlights the value of incorporating a second component into range (volatility) modelling and forecasting. In particular, we find that the proposed CCARR model fits the data better than the CARR model, and that it generates more accurate out-of-sample volatility forecasts and contains more information content about the true volatility than the popular GARCH, component GARCH and CARR models.     

核桃冷榨适宜温度的试验研究

采用单螺旋榨油机压榨的方式,对CH1500T型单螺旋榨油机进行了压榨核桃的试验,通过加热装置对榨膛辅助预热实现对核桃的预热处理,得到了不同预热时间(11 min、12 min、13 min、14 min、15 min)下核桃出油率.出油率、残油率、油脂酸价是3个常见指标(衡量榨油品质),因此经化学试验分别得到对应时间的饼粕残油率和油脂酸价,综合分析以上试验数据得到了核桃榨油的适宜预热时间.经红外测温仪测量得到该适宜预热时间下榨油机压榨后榨膛外壁36个拟定测点温度,依据热传导反问题理论,再通过Ansys Workbench热仿真得到榨膛内外壁温度分布情况.对比榨膛外表面实测温度与仿真温度,误差范围在-4.263％ ～8.155％,表明可以通过Ansys Work-bench热传导仿真来预测核桃冷榨适宜温度范围,从而得到核桃冷榨时榨膛内壁适宜温度范围为43.43～50.23℃.     

Estimators of long-memory: Fourier versus wavelets

Semi-parametric estimation methods of the long-memory exponent of a time series have been studied in several papers, some applied, others theoretical, some using Fourier methods, others using a wavelet-based technique. In this paper, we compare the Fourier and wavelet approaches to the local regression method and to the local Whittle method. We provide an overview of these methods, describe what has been done and indicate the available results and the conditions under which they hold. We discuss their relative strengths and weaknesses both from a practical and a theoretical perspective. We also include a simulation-based comparison. The software written to support this work is available on demand and we illustrate its use at the end of the paper.