基于AHP的樱园农家乐SWOT分析及发展对策

利用AHP和SWOT分析理论,提出了西安樱园观光旅游农家乐的发展策略.根据实地调研,探讨了樱园农家乐发展所面临的优势、劣势、机遇和威胁,建立了总体层次分析评价指标体系,确定了各层次的指标权重,分析了四种备选的优化方案.最后建议,樱园农家乐的发展应充分发挥“体验参与模式”的优势,把握政府引导和政策支持的机遇.     

Closed‐loop control for self‐calibration of accelerometer achieved through integrated sensor and actuator system

Microsystem Technologies - In-situ self-calibration can fundamentally solve the problem of long-term stability of the accelerometer. The implementation of external integrated micro structure to...     

基于星敏感器的姿态优化估计算法

对于采用星敏感器的航天器姿态确定问题,提出了一种快速的姿态优化估计方法;首先,根据Rodrigues参数和观测向量之间的线性关系,引入四元数,构造了不同的非奇异的优化准则;其次,借助四元数,求解了基于该准则的姿态优化算法;误差协方差分析和数值仿真结果表明,该算法与著名的QUaternion ESTmation(QUEST)算法相比,在相同的操作系统环境下,具有相同的姿态估计精度,但计算速度更快,对两种算法选取间隔为2000次的仿真步长,统计数据长度为100个采样点,最后对结果加权求平均值,统计结果显示仅为QUEST的三分之一;这种姿态优化估计方法具有一定的工程应用价值。     

空中交通预警与防撞系统(TCAS)风险及对策研究

空中交通预警与防撞系统TCAS对飞行安全非常重要,它能够通过对附近的飞机进行冲突检测,预测未来可能发生的危险,提示飞行员避免危险,帮助机组维持与其他飞机之间的空中交通安全间隔;但TCAS本身依然存在风险;在此对TCAS进行了半物理仿真测试,包括数字样机开发测试、物理样机开发测试、虚拟试飞以及数据统计分析等,对其各项功能进行测试与验证;在参阅众多相关文献的基础上,结合所做的研究工作,讨论了TCAS的主要风险,并针对这些风险,提出TCAS在设计、测试、操作方面需要改进的地方,从各方面完善TCAS,降低其风险,进一步保障飞行安全。     

在CodeWarrior编译环境下运行μC／OS—Ⅲ

μC／OS-Ⅱ是面向8／16位及低端32位单片机应用的RTOS,而新近推出的μC／OS-Ⅲ则面向高性能32位单片机,如ARMCortex等。以Cortex—M4为内核的Kinetis系列单片机,不仅用于全国大学生飞思卡尔杯智能车竞赛,也用于诸多大学的嵌入式系统教学,官方提供的开发环境是CodeWarrior。本文介绍如何利用CodeWarrior开发环境,将μC／OS-Ⅲ在Kinetis单片机上运行起来,以便将μC／OS-Ⅲ引入教学、科研与应用。     

Retraction of “Developing an integrated display of health data for aging in place”

The following article from Human Factors and Ergonomics in Manufacturing & Service Industries, “Developing an Integrated Display of Health Data for Aging in Place,” by Yang Gong and Arpita Chandra, published online on October 20, 2011 in Wiley Online Library ( www.onlinelibrary.wiley.com ), has been retracted by agreement between the authors, the journal Editors‐in‐Chief, Waldemar Karwowski and Gavriel Salvendy, and Publisher Wiley Periodicals, Inc. The retraction has been agreed as these articles were mistakenly published after being rejected.     

Interactive genetic algorithms with large population and semi-supervised learning

Interactive genetic algorithms are effective methods of solving optimization problems with implicit (qualitative) criteria by incorporating a user's intelligent evaluation into traditional evolution mechanisms. The heavy evaluation burden of the user, however, is crucial and limits their applications in complex optimization problems. We focus on reducing the evaluation burden by presenting a semi-supervised learning assisted interactive genetic algorithm with large population. In this algorithm, a population with many individuals is adopted to efficiently explore the search space. A surrogate model built with an improved semi-supervised learning method is employed to evaluate a part of individuals instead of the user to alleviate his/her burden in evaluation. Incorporated with the principles of the improved semi-supervised learning, the opportunities of applying and updating the surrogate model are determined by its confidence degree in estimation, and the informative individuals reevaluated by the user are selected according to the concept of learning from mistakes. We quantitatively analyze the performance of the proposed algorithm and apply it to the design of sunglasses lenses, a representative optimization problem with one qualitative criterion. The empirical results demonstrate the strength of our algorithm in searching for satisfactory solutions and easing the evaluation burden of the user.     

RBF neural networks-based robust adaptive tracking control for switched uncertain nonlinear systems

In this paper, a robust adaptive H∞ control scheme is presented for a class of switched uncertain nonlinear systems. Radical basis function neural networks (RBF NNs) are employed to approximate unknown nonlinear functions and uncertain terms. A robust H∞ controller is designed to enhance robustness due to the existence of the compound disturbance which consists of approximation errors of the neural networks and external disturbance. Adaptive neural updated laws and switching signals are deducted from multiple Lyapunov function approach. It is proved that with the proposed control scheme, the resulting closed-loop switched system is robustly stable and uniformly ultimately bounded (UUB) such that good capabilities of tracking performance is attained and H∞ tracking error performance index is achieved. A practical example shows the effectiveness of the proposed control scheme.     

评《清闲供、小蓬莱》

我国古典园林论著,现在常见的有计成的《园冶》、李笠翁的《一家言居室器玩部》以及明人程荩臣的《清闲供》书中的《小蓬莱》共三种,其余零星散见于古人笔记的不计。《清闲供》一书,计有不同内容的短篇十四篇,《小蓬莱》谈造园艺术,只是书中的一项内容,全文短。《清闲供》毫无现实的积极意义,经过时代的淘汰更失去其效用,成为了糟粕。     

经食道心房调搏的放射性核素心血管造影

本文应用反符合电路剔除调搏脉冲干扰的方法,制成经食道心房调搏心电心音门电路触发装置,用于经食道心房调搏的核素心血管造影。参考Tzivoni标准,当逐级增加调搏心率至140次/min或亚极量心率后发现:冠心病人有调搏后EF降低;急性心肌梗塞病人EF减低更为明显,并呈室壁反向运动。因此,心房调搏核素心血管造影有助于冠心病,特别是心肌梗塞的诊断。