基于最大似然估计的分集信号中频合成方法

为了降低分集信号合成时输入信号的信噪比要求,提出了一种分集信号的中频合成方法 。该方法利用最大似然估计和迭代算法,通过计算输出合成信号和输入分集信号的相关值获 得合成权值,在中频实现信号合成。仿真和实验结果表明,该方法放宽了输入信号信噪比要 高于解调捕获门限这一要求,能自动实现最大合成增益。     

旅游开发与徽州古村落公共空间的互动影响研究

独特的地理历史环境孕育了徽州浓郁的文化氛围,但是随着旅游业的发展,也暴露出一系列的问题,其中很关键的一点是旅游开发对村落中原有的公共空间的影响以及村落公共空间的变化对旅游发展的反馈。这个互动过程中受影响最大的就是徽州的村民,如何做到徽州文化的完美呈现,又能尽量保障当地村民在公共空间活动的权益是社会普遍关心的话题。通过徽州公共空间的转移来研究民众生活与旅游发展的冲突,旨在探索中国文化乡村的旅游开发与新农村的公共空间建设的合理途径。     

高职技能课程中运用心态教育方法的实践与研究——以《餐饮服务与管理》课程为例

本文本着以能力为本位,社会需求为导向的职业教育理念,针对学生特点和行业需求,提出以心态教育方法来促进和推动教学质量.     

山东省入境旅游流的时空结构研究

山东省旅游责源丰富,近年来入境旅游业发展迅速,游客数量和外汇收入均居全国前列.本文通过对山东省入境旅游流的时间和空间结构分析发现,改革开放以来山东省的入境旅游流可分为三个增长阶段,整体呈上升趋势;游客以外国游客为主,港澳台游客年度波动较大;客源国比较集中,入境旅游业发展不稳定,受我国和客源国的经济、政治等因素影响明显.     

Do investors actually value sustainability? New evidence from investor reactions to the Dow Jones Sustainability Index (DJSI)

Research Summary: Research exploring investor reactions to sustainability has substantial empirical limitations, which we address with a large‐scale longitudinal financial event study of the first global sustainability index, DJSI World. We examine investor reactions to firms from 27 countries over 17 years that are added, deleted, or continue on the index. We find that once relevant controls and comparisons to observationally equivalent firms beyond the index are included, DJSI events have only limited significance and/or materiality. Nonetheless, investors' valuation of sustainability around the world has evolved over time, involving diminishing reactions to U.S. firms and increasing benefits, particularly of continuation on the index, over time. The study highlights the importance of careful analysis and longitudinal global samples in making inferences about the financial effects of social performance. Managerial Summary: The debate about how investors perceive corporate social responsibility (CSR) predates Milton Friedman's famous statement that the only social responsibility of business is to increase profits. Although extensive research has studied whether sustainability contributes to financial performance, we have yet to understand whether investors believe it pays off. This financial event study of reactions to the addition, continuation, and deletion from DJSI World, the first global sustainability index, shows that investors care little about DJSI announcements. Nonetheless, there is some evidence that global assessments of sustainability are converging and that investors may increasingly be valuing continuation on the DJSI, suggesting that firms may gain at least limited benefits from reliable sustainability activities.     

技术演化Logistic模型的扩展:多种技术创新演化的选择过程分析

典型的技术演化Logistic模型描述的是当存在两种新、旧技术的竞争时,单种创新的技术随时间的演化而扩散演化的轨迹,其缺陷是没有对多种创新技术同时作用进行分析。本文考虑一个改进的创新技术的扩散模型,拓展Logistic模型的解释空间,用技术适应度、新技术选择“尝试努力”时所运行的时间、平均尝试次数、“尝试努力”成功次数的平均概率等指标,来考察在一个固定的技术选择空间内,多种技术演化的随机寻优轨迹和寻优难度;从而在一定程度上为拓展技术选择空间引入新技术,不断进行技术创新提供理论解释。     

基于MLE算法的海上角度交会测量方法及其精度分析

针对我国现有测量船单站REA测量体制精度相对较低的问题,提出了基于光电经纬仪 的海上角度交会测量方法。介绍了角度交会测量原理和设备布站原则,构建了AE-AE异面交 会测量系统,设计了基于MLE（Maximum Likelihood Estimation）算法的海上角度交会测量 算 法和船摇修正方法,仿真分析了船体姿态测量误差、设备测角误差以及站址定位误差等的影 响。仿真结果表明,站址测量误差是海上角度交会测量的最主要误差源,船体姿态测量误差 和设备测角误差对海上角度交会测量精度有一定的影响,当船体水平姿态测量误差优于20″ 、航向测量误差优于30″、设备测角误差优于20″、站址测量误差优于1 m时,海上角 度交会测量精度可达1 m。该法解决了动态条件下的飞行目标高精度测量技术难题,为 后续工程设计奠定了基础。     

走向深空--测控通信的发展方向

在传统的贸易模式下,我国经济和贸易的快速增长带来很多负面效应, 引起“三高一低”,即原材料的高强度消耗、高度污染、对国外市场的高依赖及低附加值,我国需要“三低一高”的新贸易模式来解决这些问题。本文通过图表和数据说明了旧贸易模式的危害及在旧贸易模式下我国处于不利地位,我国需要转变原有的贸易模式,并总结了将旧贸易模式转变为新贸易模式的途径。     

Knowing your place and commanding space: de/constructions of gendered embodiment in mixed-sex karate

ABSTRACT

Feminists have long acknowledged that gendered divisions in access to spaces of leisure, and how women and men physically take up that space, reproduce gender inequality. This article will explore how karate practitioners participate in the space of mixed-sex karate practice and how such uses of space de/construct gendered embodiments and a gender hierarchy. Data presented are drawn from nine months of ethnographic emersion within three karate clubs and 15 photo-elicitation interviews with karate participants from the three clubs. The findings of this paper suggest that whilst women often occupied spaces of expertise within the karate hall, gendered distinctions in uses of space emerged in the more subtle ways in which women and men used their voice, responded to the tacit and smelt dilemmas of sweat, and moved their bodies across physical space. This research highlights both the potential of physical leisure practice to ‘undo’ conventional gendered embodiments that particularly restrict women’s intentionality in the world, and the power of spatially attuned research to illuminate the minute ways in which unequal gender relations are naturalised, legitimised and done.     

规划理论和实践中的空间观念辨析

规划理论和实践中的空间观念塑造着我们周围的人造环境。空间观念的发展呈现出从绝对到相对、从时空分离转向时空关联、从一元到多元的变化趋势。20世纪以来规划理论逐渐吸纳相对空间观念,但迄今为止规划实践仍以绝对空间观念为主导。绝对空间观念成为规划实践低效性的深层原因,但是完全放弃绝对空间观念而将相对空间观念引入规划理论和实践不仅存在很多困难,而且会造成认识和实践上的混乱,科学的空间观念应该将绝对和相对结合起来形成多元空间观。我国规划理论研究和实践仍以绝对空间观念为主导,了解绝对空间观念的不足和吸纳相对空间观念的合理性具有重要的理论和实践意义。