一种基于UWB的护理机器人定位系统

护理机器人大部分时间在室内工作,由于室内环境比室外复杂且定位环境恶劣,因此需要具有很高的定位精度。为了更好地解决护理机器人的定位问题,建立了一种基于超宽带(UWB)的高精度护理机器人定位系统。首先,采用基于信号到达时间的定位模型,不需标签与基站之间的时钟同步,只需3个基站时钟同步来获取护理机器人上的标签距离各个基站的位置信息;其次,将收集到的位置信息通过室内局域网传输给利用Matlab搭建的上位机系统;最后,在上位机系统内进行偏最小二乘法线性回归,再通过遗传算法进一步对数据进行优化得到精确的位置信息,并进行仿真分析。结果表明,系统的定位精度相比于TDOA模型直接定位有较大的提高,能达到护理机器人的定位要求。基于超宽带技术的定位方法还可以应用于仓储物流小车等其他室内移动设备的高精度定位。     

农村居民消费结构变动的影响因素分析——基于新兴古典经济学与偏最小二乘回归的经验证据

分工演进表现为分工网络的细化、生产专业化与消费多样化的进程。笔者根据新古典经济学理论,选择一组涵盖专业化水平、交易效率和经济绩效的指标,运用偏最小二乘回归对农村居民消费结构变动的影响因素进行实证分析,结果显示了影响因素的阶段性差异。     

截面特性参数的计算方法探讨

本文通过实例分析,探讨了形心、惯性矩等截面特性参数的求解方法,并提出了利用AutoCAD计算时应注意的问题,对比得出使用AutoCAD求解更为简捷、准确。     

我国长三角地区国家区域政策效果评价研究——基于偏相关和多元分布滞后模型

文章利用长三角地区上海市、江苏省以及浙江省的经济增长数据,构建多元虚拟变量分布滞后模型对国家长三角地区的区域发展规划效果进行评价。研究结果表明国家长三角区域发展规划政策出台后,不同政策变量对三地市的经济增长的影响存在差别,其中中央补助收入在上海和江苏的经济增长弹性显著提高,但是中央补助收入对浙江省的经济增长促进作用有所下降,同时中央转移支付与税收返还政策效果存在时滞。最后提出了结构上调整国家区域发展规划政策等对策建议。     

基于偏最小二乘的泰国菠萝出口影响因素实证研究

本文采用偏最小二乘回归模型(PLS),以泰国菠萝贸易为例,通过变量投影重要性准则筛选自变量,由交叉有效性提取主成分,进而建立偏最小二乘回归模型。深入分析了各指标对泰国菠萝出口贸易的影响。研究表明泰国菠萝出口与原料价格及工厂生产加工速度密切相关,并且偏最小二乘回归的拟合效果优于普通最小二乘回归。     

Modelling the impact of the ‘fast track’ land reform policy on Zimbabwe's maize sector

Zimbabwe has recently gone through a widely criticised land reform process that is argued to be the cause of subdued agricultural production. This paper attempts to present a counterfactual picture of the maize market in Zimbabwe had land reform been managed appropriately. The counterfactual is developed through a partial equilibrium framework in order to quantify the impact of the land reform programme. This, to our knowledge, is the first attempt at applying a partial equilibrium framework to an analysis of the impact of land reform. The results of the post-2000 land reform policy simulation showed that actual total maize output was lower than what could have been produced if it was under a pre-2000 land reform system. The study validates the assertion that land reforms contributed to the contraction of output. These results suggest the need for a well planned and executed land reform process, which can still play an important role in output growth and food security.     

Partial Industrialisation in Tourism: A New Model

Certain forms of human activity, such as sport, education and tourism, can be described as being partly industrialised; they are supported partly by organisations with industrial relationships to the particular activity (e.g. tourism industries, sports industries, and so on), and partly by other factors. The latter includes business organisations whose relationship to the activity might be direct and commercial but is non-strategic, non-industrial. Partial industrialisation in tourism (PIIT) has been explored by a handful of researchers interested in its nature, causes and implications. However, the diagrammatic model used in the exploratory studies is awkward, a defect that probably helps explain why PIIT has not become widely recognised in the community of tourism researchers. A new model enables clearer insight and should facilitate understanding and greater recognition. Using the new model, an empirical research project in a mass destination provided substantial evidence for PIIT. Implications arise for many issues, including how tourism is conceptualised, strategic business management, destination competitiveness, destination development and promotion, seasonality, environmental activism, employment numbers, vocational training, planning and government policy.     

OPTIMAL CONSUMPTION AND PORTFOLIO DECISIONS WITH PARTIALLY OBSERVED REAL PRICES

We consider optimal consumption and portfolio investment problems of an investor who is interested in maximizing his utilities from consumption and terminal wealth subject to a random inflation in the consumption basket price over time. We consider two cases: (i) when the investor observes the basket price and (ii) when he receives only noisy observations on the basket price. We derive the optimal policies and show that a modified Mutual Fund Theorem consisting of three funds holds in both cases. The compositions of the funds in the two cases are the same, but in general the investor's allocations of his wealth into these funds will differ. However, in the particular case when the investor has constant relative risk-aversion (CRRA) utility, his optimal investment allocations into these funds are also the same in both cases.     

分数布朗运动环境下的美式看涨期权的定价方法

在分数布朗运动模拟算法基础上,提出了分数布朗运动环境下标的资产价格过程的一种数值模拟方法。然后应用于欧式和美式看涨期权定价。结果表明,该方法具有很快的收敛速度,而且基于最小二乘方法和偏最小二乘方法的美式看涨期权价格,都与对应的欧式看涨期权价格几乎完全一样。这恰恰验证了不支付红利的条件下,美式看涨期权不应该提前执行的理论论断。     

互联网金融对商业银行风险承担的影响研究——基于中国30家商业银行的实证分析

为了研究互联网金融对商业银行风险承担的影响,本文以2009—2018年互联网金融对中国30家典型商业银行风险承担影响的数据为基础,运用动态面板广义矩估计方法对互联网金融对我国商业银行风险承担的影响进行了研究与分析。结果表明:(1)互联网金融对我国商业银行风险承担的影响呈现倒U形分布,即互联网金融发展初期通过抢占市场份额,加剧了行业竞争,抢占了商业银行利润,进而加大了商业银行风险承担的成本;但随着商业银行对互联网前沿技术的不断融合、金融产品服务的创新以及风险管控水平的提升,商业银行风险承担的成本下降。(2)面对互联网金融的冲击,不同类型商业银行对风险承担反应具有异质性:在宏观层面,大型国有银行拥有庞大的资产规模和政策保障,对其冲击反应较为滞后;股份制银行和城市商业银行缺乏上述优势,对其冲击反映较为敏感,但股份制银行后期风险承担显著下降;农村商业银行因主要服务于乡村建设,受其影响较为有限。在微观层面,面对互联网金融的冲击,与资本充足率和流动性水平较低的大型商业银行相比,资本充足率和流动性水平较高的小规模商业银行风险承担显著增加。