利用时变噪声贝叶斯卡尔曼滤波的室内移动目标定位

基于射频识别的指纹滤波定位技术是当前室内定位中常使用的技术之一。针对该技术存在的卡尔曼滤波算法不能准确适应环境噪声变化，致使定位精度不高的问题，提出了一种适应时变噪声的贝叶斯卡尔曼滤波算法。所提算法结合Sage-Husa滤波模型和贝叶斯模型，实现了过程和测量协方差矩阵的最优化，有效地降低了噪声，提高了指纹滤波定位的精度。实验结果表明，与变分贝叶斯卡尔曼滤波和Sage-Husa滤波相比，无障碍情况下，基于改进算法的定位精度提高了6%以上；有障碍干扰下，则提高了14.6%以上。     

Structural change,the push-pull hypothesis and the Spanish labour market

This paper proposes a small-scale general equilibrium model of structural transformation with a non-agricultural labour market characterized by search frictions. The model is used to investigate the role of sectoral TFPs as main drivers of structural change and a new growth accounting exercise allows a quantitative reassessment of the importance of the labour reallocation bonus in structural transformation in the presence of labour market frictions. The model is calibrated to data for post-war Spain and its transition from dictatorship to democracy. Counterfactual simulations point towards productivity improvements in agriculture as the main driver, while modifications in labour market institutions affect mainly the labour market itself, with only a modest effect on structural change.     

影响农田残膜回收体系建设的关键因素识别研究

［目的］从农户、企业和政府3个维度入手，系统分析农田残膜回收体系建设的影响因素，以期为促进农田残膜回收体系的建立与农田生态环境的修复提供借鉴。［方法］文章运用模糊集理论与决策实验分析法定量考察农田残膜回收体系构建中各影响因素之间的相互关系，并对关键因素进行有效识别。［结果］政府和农户对残膜回收体系建设具有较为长期的影响，是影响农田残膜回收体系建设的原因因素； 企业对残膜回收体系的建设起直接作用，是结果因素； 农户的残膜回收收益、企业的净收益预期、回收物流体系、技术创新能力、政府的技术支持、税收优惠及补贴政策是影响农田残膜回收体系建设的6个最关键因素，其中技术支持、税收优惠及补贴对体系中其他因素产生重要影响。［结论］要高度重视农户对农田残膜回收体系建设的重要性，要制定出有效的补贴制度激励农户参与体系建设； 政府对残膜回收机械研发投入及残膜加工企业的技术支持对残膜回收体系建设能够起到推动作用。     

Do anti-bribery laws reduce the cost of equity? Evidence from the UK Bribery Act 2010

We examine the impact of the UK Bribery Act 2010 on the implied cost of equity. We find a significant reduction in the cost of equity amongst UK firms with high bribery exposure after the passage of the Bribery Act. We further show that the Bribery Act improves internal control systems and increases stock liquidity of firms with high bribery exposure. Our results suggest that more stringent anti-bribery regulations are not always bad for the firm.     

Shannon's Entropy and Its Generalisations Towards Statistical Inference in Last Seven Decades

Starting from the pioneering works of Shannon and Weiner in 1948, a plethora of works have been reported on entropy in different directions. Entropy‐related review work in the direction of statistical inference, to the best of our knowledge, has not been reported so far. Here, we have tried to collect all possible works in this direction during the last seven decades so that people interested in entropy, specially the new researchers, get benefited.     

基于索洛余值法的马铃薯全要素生产率探析

[目的]根据2011—2016年的全国农产品成本收益数据,从物质资料投入、劳动力投入和技术投入等方面确定5个指标对全国16个省(区、市)的马铃薯全要素生产率的变动进行研究。[方法]运用含参数的索洛余值法,构建柯布道格拉斯生产函数模拟我国马铃薯生产的投入和产出之间的关系,通过回归分析得到各个生产要素对马铃薯生产的贡献大小和影响程度。[结果](1) 2012—2016年,我国马铃薯全要素生产率变化呈"N"型,未来有上升趋势;(2)在规模报酬不变的假定条件下,广义的科技进步对马铃薯单产的贡献率高达57%,肥料和劳动力投入的弹性分别为0. 28和0. 15,广义的科技进步对马铃薯生产影响十分显著;(3)我国马铃薯TFP变化区域差异明显。[结论]基于以上研究提出了提高肥料的科技含量、加速马铃薯经营主体的人力资本积累、强化政策扶持与制度建设和不断推进科技创新等政策性建议。     

一种基于卷积运算与全变分模型的图像去噪方法

梯度模值较易受到外界影响，导致全变分模型在大噪声点处往往不能很好地消除噪声，从而产生阶梯效应。针对该问题，提出了一种基于卷积运算与全变分模型的图像去噪方法。首先，针对以扩散形式获得的图像像素点进行卷积运算，利用滤波去噪降低大噪声点的灰度值；其次，以能量泛函形式构建图像全变分模型，并求解泛函对应的拉格朗日方程极小值来实现图像去噪；最后，将去噪后图像作为双边滤波算法的引导图像进行二次去噪，从而进一步提升图像去噪质量。仿真实验结果表明，与经典方法相比，该模型对去噪过程中的阶梯效应问题具有较好的处理效果。     

应用EEMD方法对某纪念碑“军号声”成因的分析

对江苏镇江茅山苏南抗战胜利纪念碑爆竹爆炸引起"军号声"这一奇特现象进行了实地的测试,从声波干涉原理及梳状滤波原理出发,解释了声音由多级台阶反射叠加后形成"军号声"的基本原理。应用集合经验模态分解方法(EEMD),对多级台阶反射声信号进行时频分析,通过与实验室人工吹出军号声信号特征的分析结果做比较,得出"军号声"是由纪念碑及其前面多级台阶反射而引起的。     

Emotions Matter: Sentiment and Momentum in Foreign Exchange

The author introduces news sentiment as a variable that can explain and predict subsequent changes in the USD/EUR exchange rate and therefore close a gap in the foreign exchange literature. By applying the concept of frequency filtering from the domain of electrical engineering, the author shows an innovative way of filtering for noise not only in news sentiment, but also in price momentum. The author finds that news sentiment is not correlated to price momentum, and that trading strategies based on news sentiment achieve around twice as high information ratios (up to 0.9) than with trading strategies based on price momentum.     

基于主题模型的英语写作批阅系统个性化推荐模块设计与实现

伴随着自然语言处理技术的发展,计算机代替人工评阅作文已成为可能,计算机评阅的便利,带来了巨大的用户量及作文量,而针对不同用户准确的推荐各自感兴趣的范文可以更加丰富及开阔自己的写作能力。本文提出了一种新的推荐算法,将概率主题模型引入到个性化推荐中,并在实验室的写作批阅平台(简称CMET)上进行了实现。全文介绍了协同过滤推荐和主题模型的相关技术,对传统的协同过滤算法进行了改进,在此基础上,提出了新的推荐算法——基于主题模型的协同过滤(BaseLDACF),并将该推荐算法进行了实现。