飞机概念设计的多向思维

飞机设计是专业性较强的设计门类,传统上一向以技术指标为导向进行设计.然而从工业设计的视角而言,设计概念发展是多向的,是从多种可能中抉择出的最佳结果.这有赖于开阔的设计思维,全面的认识和思考设计对象.从设计实践出发,飞机概念设计可以以基于原型的变型化设计、基于飞行技术发展趋势的概念化设计及基于环保的绿色化设计等几个方向,...     

航空发动机控制系统传感器智能故障诊断

航空发动机控制系统故障诊断一直是一个重点研究课题,本文使用智能故障诊断技术对发动机控制系统传感器进行状态检测和故障诊断。具体方法为:以传感器之间的冗余关系为基础,利用基于智能粒子群算法的小波神经网络建立传感器输出预测器,通过准确预测传感器输出,实现对传感器的检测和故障诊断。通过仿真验证,本文所使用智能故障诊断技术是可行的,具有一定的借鉴价值。     

异质信念、通货幻觉和我国房地产价格泡沫

房地产基本价值是由其未来的现金流(即租金)和贴现率决定的,异质信念与通胀幻觉分别从投资者对房地产未来现金流分布的信念差异和对贴现率的估计偏差两方面解释了房地产价格泡沫的形成机制。本文基于1994~2010年中国房地产市场季度数据,利用时变现值模型估计中国房地产市场的基本价值,进而给出房地产价格泡沫,并检验中国房地产价格泡沫的形成机制。研究发现,异质信念和通胀幻觉都勾勒出了中国房地产价格泡沫形成的画面,但相对于通胀幻觉,异质信念是中国房地产价格泡沫形成的主导因素。     

大飞机研制中的技术创新路径选择

大飞机研发制造已成为我国新世纪的国家战略。增强自主创新能力,构建大飞机产业技术创新体系已成当务之急。因而建立产品开发平台,积极开展国际合作,提高核心技术开发能力,掌握自主知识产权显得尤为重要。     

策略性产品投放市场研究方法

This paper proposes a method to analyze how the manufacturers make product launch decisions in a multi-product oligopoly market, and how the heterogeneity in their products affects the manufacturers’ decisions on model launch and withdrawal.      

Optimal consumption and the environment Choosing between ‘clean’ and ‘dirty’ goods

In this paper, a model with heterogeneous consumption goods is presented. Consumers are assumed to choose between two different consumption goods, characterized by a different impact on the environment. This implies that, in a decentralized economy, government can sustain the social optimum by setting two Pigouvian taxes: one on production as a whole and the other on dirty consumption acting as an incentive in favour of clean consumption. In accordance with the previous literature, a trade-off between a clean environment and economic activity evolves. However, this trade-off is now mitigated by the additional taxation on polluting consumption which allows the control of pollution stock evolution through the substitution between clean and dirty commodities.     

Ordering the largest claim amounts and ranges from two sets of heterogeneous portfolios

This paper investigates the ordering properties of the largest claim amounts and sample ranges arising from two sets of heterogeneous portfolios. First, some sufficient conditions are provided in the sense of the usual stochastic ordering to compare the largest claim amounts from two sets of independent or interdependent claims. Second, comparison results on the largest claim amounts in the sense of the reversed hazard rate and hazard rate orderings are established for two batches of heterogeneous independent claims. Finally, we present sufficient conditions to stochastically compare sample ranges from two sets of heterogeneous claims by means of the usual stochastic ordering. Some numerical examples are also given to illustrate the theoretical findings. The results established here not only extend and generalize those known in the literature, but also provide insight that will be useful to lay down the annual premiums of policyholders.     

基于卫星中继的无人机图像传输系统

基于卫星中继的无人机图像传输系统在遥感图像的传输中有着十分重要的作用。首先讨论了这种系统的应用意义 ,然后提出了一种具体的实现方案 ,对系统中的几个关键部分的设计进行了详细分析。目前的实验成果表明 ,这种基于卫星中继的无人机图像传输系统方案是可行的。     

外形设计对飞机隐身性能影响分析

飞机的隐身技术是一个多学科交叉的技术领域,措施多样,外形设计作为其中的一项重要手段也备受关注.文中着重讨论并分析了如何通过有效外形设计措施,降低飞机主要威胁方向雷达电磁波的反射,从而降低其被雷达等探测源截获的风险.