企业研究与试验成本的规划与控制

企业的技术创新成为企业竞争的一项内容,企业要进行自主创新,必然要进行项目研究与试验,发生一系列的研究与试验成本。但目前我国企业的研究与试验成本控制方面存在一系列的问题。文章从研究与试验成本的时间规划、研究与试验成本项目规划、研究与试验成本的控制手段规划进行展开论述,并提出在规划控制中要注意克服一系列问题。     

The COMPLEIK subroutine of the IONORT-ISP system for calculating the non-deviative absorption: A comparison with the ICEPAC formula

The present paper proposes to discuss the ionospheric absorption, assuming a quasi-flat layered ionospheric medium, with small horizontal gradients. A recent complex eikonal model (Settimi et al., 2013b) is applied, useful to calculate the absorption due to the ionospheric D-layer, which can be approximately characterized by a linearized analytical profile of complex refractive index, covering a short range of heights between h₁ = 50 km and h₂ = 90 km. Moreover, Settimi et al. (2013c) have already compared the complex eikonal model for the D-layer with the analytical Chapman’s profile of ionospheric electron density; the corresponding absorption coefficient is more accurate than Rawer’s theory (1976) in the range of middle critical frequencies. Finally, in this paper, the simple complex eikonal equations, in quasi-longitudinal (QL) approximation, for calculating the non-deviative absorption coefficient due to the propagation across the D-layer are encoded into a so called COMPLEIK (COMPLex EIKonal) subroutine of the IONORT (IONOspheric Ray-Tracing) program ( Azzarone et al., 2012). The IONORT program, which simulates the three-dimensional (3-D) ray-tracing for high frequencies (HF) waves in the ionosphere, runs on the assimilative ISP (IRI-SIRMUP-P) discrete model over the Mediterranean area ( Pezzopane et al., 2011). As main outcome of the paper, the simple COMPLEIK algorithm is compared to the more elaborate semi-empirical ICEPAC formula (Stewart, undated), which refers to various phenomenological parameters such as the critical frequency of E-layer. COMPLEIK is reliable just like the ICEPAC, with the advantage of being implemented more directly. Indeed, the complex eikonal model depends just on some parameters of the electron density profile, which are numerically calculable, such as the maximum height.     

Unmanned aerial vehicle swarm mission reliability modeling and evaluation method oriented to systematic and networked mission

With the development of Unmanned Aerial Vehicle (UAV) system autonomy, network communication technology and group intelligence theory, mission execution in the form of a UAV swarm will be an important realization of future applications. Traditional single-UAV mission reliability modeling methods have been unable to meet the requirements of UAV swarm mission reliability modeling. Therefore, the UAV swarm mission reliability modeling and evaluation method is proposed. First, aimed at the interdependence among the multiple layers, a multi-layer network model of a UAV swarm is established. At the same time, based on the system having the following characteristics—using a mission chain to complete the mission and applying the connectivity of the mission network—the mission network model of a UAV swarm is established. Second, vulnerability and connectivity are selected as two indicators to reflect the reliability of the mission, and aimed at random attack and deliberate attack, vulnerability and connectivity evaluation methods are proposed. Finally, the validity and accuracy of the constructed model are verified through simulations, and the model and selected indicators can meet the reliability requirements of the UAV swarm mission. In this way, this study provides quantitative reference for UAV-swarm-related decision-making work and supports the development of UAV-swarm-related work.     

Network analysis of Chinese air transport delay propagation

The Chinese air transport system has witnessed an important evolution in the last dec-ade, with a strong increase in the number of flights operated and a consequent reduction of their punctuality. In this contribution, we propose modelling the process of delay propagation by using complex networks, in which nodes are associated to airports, and links between pairs of them are assigned when a delay propagation is detected. Delay time series are analysed through the well-known Granger Causality, which allows detecting if one time series is causing the dynamics observed in a second one. Results indicate that delays are mostly propagated from small and regio-nal airports, and through flights operated by turbo-prop aircraft. These insights can be used to design strategies for delay propagation dampening, as for instance by including small airports into the system's Collaborative Decision Making.     

Analytical method of dynamic properties of FRP based on micromechanical level

A mathematic model is proposed for predicting the dynamic properties of fiber reinforced plastic composites(FRP) with interphase. Dynamic properties mainly include loss factors and elastic moduli. The results of elastic moduli from the present model are compared with other models. Elastic moduli E11, E22, G12, G23 and loss factors η11, η22, η12 and η23 of FRP are calculated and a study of the effect of elastic modulus EIand loss factor ηI of interphase on dynamic properties in FRP is carried out here. In this paper, E11 linearly increases with EI, but the growth rate is slow. E22, G12, G23 increase rapidly for lower value of EI. The longitudinal loss factor g11 decreases with the increase of EIin the case of ηI 0.0026. But η11 linearly increases with EIin larger range of ηI, ηI≥ 0.0026. On the contrary, transverse loss factor η22, transverse shear loss factors η23 and longitudinal shear loss factors η12 increase with increase of EIin the case of lower value of ηI, but decreases at larger value of gI. And they also show insensitivity to EIat higher value.     

剖析"飞行操纵系统课件"开发中的几个技术问题

分析了使用3DSMAX3 Authorware5设计工具开发“飞机飞行操纵系统多媒体课件”设计过程中几个重要技术问题。主要包括:复杂三维模型的建立、建模工具的灵活使用、三维动画设计方法、多任务控制面板的设计以及计算机考试模块的设计。提出了多任务控制面板及计算机考试系统的模块化设计思路,优化的设计模型,提高了软件的维护性及拓展性。     

ARJ21复杂双曲面长桁零件弯扭复合冷成型方法

通过对零件几何特征和计算机辅助软件的分析，在掌握零件变化规律的基础上，确定了零件的成型方法，以及实验确定成型过程中各参数值。     

Vulnerability analysis for airport networks based on fuzzy soft sets: From the structural and functional perspective

Recently,much attention has been paid to the reliability and vulnerability of critical infrastructure.In air traffic systems,the vulnerability analysis for airport networks can be used to guide air traffic administrations in their prioritization of the maintenance and repair of airports,as well as to avoid unnecessary disturbances in the planning of flight schedules.In this paper,the evaluation methods of airport importance and network efficiency are established.Firstly,the evaluation indices of airport importance are proposed from both the topological and functional perspectives.The topological characteristics come from the structure of airport network and the functional features stem from the traffic flow distribution taking place inside the network.Secondly,an integrated evaluation method based on fuzzy soft set theory is proposed to identify the key airports,which can fuse together importance indices over different time intervals.Thirdly,an airport network efficiency method is established for the purpose of assessing the accuracy of the evaluation method.Finally,empirical studies using real traffic data of US and China’s airport networks show that the evaluation method proposed in this paper is the most accurate.The vulnerability of US and China’s airport networks is compared.The similarities and differences between airport geography distribution and airport importance distribution are discussed here and the dynamics of airport importance is studied as well.     

极限重心对单旋翼直升机悬停及小速度飞行安全的影响

系统介绍了确定单旋翼直升机极限重心的依据;对比了极限重心对单旋翼直升机悬停、低速飞行的影响,分析了三种机型手册中的有关规定,就完善有关规定提出了建议;最后阐述了克服极限重心不利影响的对策。     

网络化战争中的复杂网络拓扑建模

网络化战争中网络拓扑模型的构建是利用复杂网络理论研究网络化战争的基础。本文根据网络化战争的特点,从复杂网络动力学角度,对BA模型进行扩展,通过在节点分类和连接规则两方面增添假设,构建了网络化战争中的复杂网络拓扑模型。仿真结果表明,在该演化规则下生成的网络具有无尺度和小世界特性。对网络模型抗毁性的研究为网络化战争中攻击节点的选择及网络的构建和改进提供理论依据。