4G手机无线接入系统设计及实现

用射频微波电路集成技术设计第4代(4G)手机无线接入系统．从分布参数概念出发，主要在smith圆图上进行电路设计．由微带线进行电路的实现，电路将各功能单元集成在微带基板上，具有体积小、重量轻、可靠性高、与手机其他电路易于共形等特点．运用网络转移参量矩阵理论进行了系统响应预估，结果表明所设计的无线接入系统满足4G移动终端的性能要求．     

随机风-浪一体化降维建模及风机结构可靠度研究

基于随机脉动风场和随机波浪力场的谱表示降维模拟方法,采用脉动风速Davenport谱与波浪P-M谱对风、浪谱参数进行一体化构造,并应用相同的基本随机变量来保障风、浪模拟的概率信息一致,实现了随机风-浪一体化降维建模。进一步,基于ANSYS有限元软件建立了近海风机塔架数值计算模型,并以顶点位移为指标,进行了三种工况下结构的动力可靠度分析。数值算例验证了随机风-浪一体化降维建模方法的有效性。结构动力分析结果表明,风荷载对风机塔架顶点位移响应的影响占主导地位,同时波浪荷载的作用亦不可忽略。此外,随机风-浪一体化降维方法生成的代表性样本概率信息完备,可与概率密度演化理论结合实现海工结构在风浪共同作用下的精细化动力响应及可靠度分析。     

综合网管中基于模型驱动的元数据管理

提出了一种基于模型驱动的元数据管理方案．方案采用了基于模型的形式化描述方法，统一了专业网管子系统间的元数据模式；通过引入模型驱动技术，从元模型的抽象层次消除了不同专业网管子系统之间存在的“信息孤岛”；方案还对综合网管环境下的元数据理论和交换机制进行了研究，并给出了元数据的管理框架以及元数据交换的Java接口映射．     

Three modes of STEM integration for middle school mathematics teachers

Of the four subjects in an integrated science, technology, engineering, and mathematics (STEM) approach, mathematics has not received enough focus. This could be in part because mathematics teachers may be apprehensive or unsure about how to implement integrated STEM education in their classrooms. There are benefits to integrated STEM in a mathematics classroom though, including increased motivation, interest, and achievement for students. This article discusses three methods that middle school mathematics teachers can utilize to integrate STEM subjects. By focusing on open‐ended problems through engineering design challenges, mathematical modeling, and mathematics integrated with technology middle school students are more likely to see mathematics as relevant and valuable. Important considerations are discussed as well as recent research with these approaches.     

对于金融资产波动率估计的双域组合方法

Time- and state-domain methods are two common approaches for nonparametrically estimating the volatility of financial assets. Economic conditions vary over time in real financial market. It is reasonable to expect that volatility depends on both time and price level for a given state variable. Recently, Fan, et al （2007） proposed the idea of dynamically integrated method in both time-and state domain. This idea has become an interesting topic in the estimation of volatility. In this paper, our purpose is to discuss the integrated method in the estimation of volatility. Simulations are conducted to demonstrate that the newly integrated method outperforms some old ones, and the results of simulations demonstrate this fact. Furthermore, we establish its asymptotic properties.     

Maximum integrated likelihood estimator of the interest parameter when the nuisance parameter is location or scale

The problem of estimation of an interest parameter in the presence of a nuisance parameter, which is either location or scale, is studied. Two estimators are considered: the usual maximum likelihood estimator and the estimator based on maximization of the integrated likelihood function. The estimators are compared, asymptotically, with respect to the bias and with respect to the mean squared error. The examples are given.     

电力市场环境下计及V2G和多类型需求响应的综合能源系统多目标优化模型

园区综合能源系统(Park integrated energy system,PIES)是满足用户多种用能需求的一种重要途径,但由于内部分布式能源机组出力具有不确定性,且与负荷在时间维度上存在一定的不匹配性,限制了能源利用效率和经济效益的提升.因此,本文首先在构建耦合热电的PIES的基础上,构建了多类型需求响应模型;其...     

The modeling of coalition for environmental protection within co-utility framework

The game theoretic modelling of coalition for environmental protection within the framework of a new concept of co-utility is discussed. The co-utility concept contains mainly two elements. Firstly, agents can increase their payoffs by collaborating with each-other. Secondly, the outcome of collaboration is robust towards internal and external disturbances. The advantages of using of co-utility are two-fold. Primarily, the co-utility concept is broad and can serve as an umbrella concept in all applications where agents have a space for simultaneous improvement of payoffs. Secondly the co-utility concept can be associated with different stability concept such as myopic or farsighted stability. The myopic and farsighted co-utile sets are defined and their element-co-utile outcomes are found.     

激光多普勒自主测速仪天线安装误差对测速精度的影响

为了减小激光多普勒自主测速仪天线安装误差引起的测速误差,以多普勒频移原理为基础,通过旋转矩阵的复合变换推导出测速误差与安装误差间的函数关系,分析了三个安装误差角对三维测速精度的影响,并对旋转矩阵采用Bursa模型线性化后在整体最小二乘准则下给出安装误差角的最优估计,从而实现测速误差的补偿。仿真结果表明:测速误差随速度的增大而增大,影响纵向、横向测速精度的主要因素是偏航角,影响垂向测速精度的主要因素是纵倾角,补偿后三维测速误差显著减小。     

键合型掺铒纳米晶-聚合物波导放大器的制备

为了克服主客掺杂型有源材料均匀性和稳定性差的问题,采用键合掺杂方法,将高温热解法制备的油酸修饰掺铒氟钇钠纳米晶粒与甲基丙烯酸甲酯发生共聚反应,形成键合型有源芯层材料。纳米晶粒均匀固定在聚合物分子链上,抑制了高浓度掺杂时的团聚析出且材料更稳定。纳米粒子在聚合物中的质量百分比达到约1wt%,具有良好的成膜性,用原子力显微镜照片观察薄膜表面粗糙度为1.76 nm。用椭偏仪测量薄膜光学性质,并用柯西色散模型拟合出薄膜折射率随波长的变化关系,材料在1550 nm信号光波长的折射率为1.485。设计嵌入式波导结构,采用有限元方法进行模式分析和计算光场强度分布。采用紫外光刻和感应耦合等离子体刻蚀工艺制备凹槽形下包层,填充有源材料制备条形波导放大器。实验结果表明,当1550 nm信号光功率为0.1mW,1480 nm泵浦光功率为390 mW时,在1.2 cm长的样品中得到了3.58 d B的信号光相对增益。