基于瑞利熵的多无源传感器数据关联算法

针对当前多无源传感器数据关联算法构造关联代价时,未考虑位置估计不确定性所引入的误差,提出一种基于位置估计不确定性的被动传感器数据关联算法。首先通过量测与伪量测概率密度函数之间的瑞利熵构建关联代价函数,以准确描述两个相似的概率密度函数之间差异,然后通过具体实验测试本文算法的有效性和优越性。实验结果表明,相对于当前经典的数据关联算法,本文算法提高了数据关联的正确率和速度,具有更高的实际应用价值。     

果树种植最佳土地租赁期的数学模型建构

以种植果树为例,根据果树种植的客观规律,引进折扣因子δ=U-α,给出了通过确定投资合同期使利润达到最大的数学模型,并进行了讨论和推广.     

动态环境约束下企业的资本积累

本文讨论动态环境约束下企业的动态投资行为,拓广了文献[4]的结果.为了使讨论的问题更符合实际情况,本文假设政府设定的污染排放上限是与企业的规模大小有关,即假设污染排放上限是生产资本的函数,讨论动态环境约束下企业的最佳动态投资行为,并为政府制定污染排放政策提供依据.     

Welfare Cost of Model Uncertainty in a Small Open Economy

This paper extends the canonical small open-economy real-business-cycle model, when considering model uncertainty. Domestic households have multiplier preferences, which leads them to take robust decisions in response to possible model misspecification for the economy’s aggregate productivity. Using perturbation methods, the paper extends the literature on real business cycle models by deriving a closed-form solution for the combined welfare effect of the two sources of uncertainty, namely risk and model uncertainty. While classical risk has an ambiguous effect on welfare, the addition of model uncertainty is unambiguously welfare-deteriorating. Hence, the overall effect of uncertainty on welfare is ambiguous, depending on consumers preferences and model parameters. The paper provides numerical results for the welfare effects of uncertainty measured by units of consumption equivalence. At moderate (high) levels of risk aversion, the effect of risk on household welfare is positive (negative). The addition of model uncertainty—for all levels of concern about model uncertainty and most risk aversion values—turns the overall effect of uncertainty on household welfare negative. It is important to remark that the analytical decomposition and combination of the effects of the two types of uncertainty considered here and the resulting ambiguous effect on overall welfare have not been derived in the previous literature on small open economies.     

温度/应变/扭曲三参量同时测量低成本传感系统

提出了一种利用布喇格光纤光栅反射光作信号源、高频CO2激光脉冲写入的长周期光纤光栅和超周期光纤光栅作传感器实现温度、应变和扭曲同时测量的全光栅型低成本强度解调传感方案.文中利用长周期光纤光栅边缘滤波效应实现了温度、应变和扭曲传感信号的实时解调.实验结果表明,其温度和应变的测量灵敏度分别为－0.211 dB/℃和－0.012 dB/10με;而扭曲率的测量灵敏度为0.4394 dB/(rad·m－1),是该法写入普通LPFG的4倍以上.     

燃料电池技术发展现状与展望

燃料电池是一种高效、清洁的电化学发电装置,近年来得到国内外普遍重视.本文详细阐述了燃料电池的近期研究进展与未来面临的挑战及发展方向。燃料电池在宇宙飞船、航天飞机、潜艇动力源已经得到应用;在汽车、电站及便携式电源等民用领域展现了成功的示范,但低成本、长寿命仍然是商业化面临的瓶颈问题.未来我国应大力推进燃料电池在水下潜器、航天飞行器等特殊领域的应用,解决高可靠性与安全性及环境适应性等关键问题;同时,在民用领域要实现燃料电池寿命与成本兼顾,从材料、部件及系统等3个层次深入技术改进与创新,尽快推进燃料电池的商业化.     

丙烯酸水溶液聚合法制备PTFE/PAA/Nafion膜及其性能

采用廉价的多孔聚四氟乙烯(PTFE)膜作为基底, 用少量的Nafion与PTFE膜复合可制备低成本的质子膜. 但疏水性的PTFE膜与亲水性的Nafion膜结合性不佳. 基于此, 本文对疏水性的PTFE膜材料表面进行设计, 先采用丙烯酸对疏水性的PTFE膜表面进行亲水性改性, 再喷涂亲水性Nafion膜, 完成低成本PTFE/PAA/Nafion膜的制备. 实验结果表明, 改性前的PTFE膜材料水接触角为150°, 改性后的膜接触角变为55.6°, 亲水性大幅上升, 膜的机械强度和尺寸稳定性(断裂强度为25.2 MPa, 80 ℃下的溶胀率为11.9%)均优于Nafion117膜, 而 Nafion用量则节省了60%. PTFE/PAA/Nafion膜具有高质子导通率(80 ℃下达到131.9 mS/cm), 接近于Nafion117膜, 最大功率密度可以达到404.2 mW/cm².     

供应链集中决策下RFID技术应用决策分析

RFID技术可以对供应链系统中的产品信息进行有效追溯和实时共享,以化解系统管理效率、安全防范、监控和保障能力极其低下等问题.但是,由于应用成本的制约,使很多附加值较低的行业仍望而却步,严重制约了RFID技术的发展和普及.以单个零售商和供应商组成的供应链系统为研究对象,首先,对基于RFID的供应链产品入库及日常盘点管理流程进行了简要分析;在此基础上,分别构建了集中决策下采用与不采用RFID技术时的供应链利润模型,并对其最优决策问题进行详细分析,得出供应链系统在集中决策下实施RFID技术的投资决策条件,所得结论可以为供应链系统在集中决策下实施RFID技术应用决策问题提供理论支持.     

带模糊约束的最小费用流问题

本文首次提出了带模糊约束的最小费用流问题,建立了相应的数学模型并给出了求解这一模型的有关算法。最后,给出了一个具体实例。     

Spanning network games

We study fundamental properties of monotone network enterprises which contain public vertices and have positive and negative costs on edges and vertices. Among the properties studied are the nonemptiness of the core, characterization of nonredundant core constraints, ease of computation of the core and the nucleolus, and cases of decomposition of the core and the nucleolus. Received December 1994/Final version March 1998