数字多用表示值误差测量不确定度自动评定的设计

针对数字多用表型号多、校准项目多,校准后应给出整个测量范围内的测量结果不确定度,采用手动进行不确定度评定费时费力、容易出错、工作效率低等问题,在VEE Pro软件开发平台上,设计开发出数字多用表示值误差测量结果不确定度自动评定系统。该系统包括带接口数字多用表不确定度评定和不带接口数字多用表不确定度评定两个模块,可自动进行不确定度评定及存档。同时结合实例,给出了直流电压示值误差测量不确定度评定结果。使用结果表明：该系统操作简便,提高了工作效率及准确度,减小了人为误差。     

隔热层厚度和数量对太空多层光学窗口温度分布的影响

 航天器上常安装有用于科学观察的多层光学窗口,其温度分布的均匀性会影响成像质量。运用射线踪迹-节点分析法的任意多层镜反射辐射与导热耦合换热模型,研究了隔热层厚度及数量对太空中多层光学窗口温度分布的影响。光学窗口的吸收系数、折射率随波长的变化用一组矩形谱带来近似。研究显示太空中热辐射在光学窗口的冷却过程中起着非常重要的作用,在离玻璃层表面附近很薄的一层玻璃介质内,辐射与导热存在强烈的耦合作用。隔热层厚度越薄,其内的温度分布越均匀,有利于提高成像质量。隔热层数量越多,光学窗口各层玻璃的温度分布越均匀,有利于提高成像质量,但是隔热层最佳数量的确定还需综合考虑其它因素。     

路由算法在LEO通信星座构型优化中的应用

低轨(LEO,Low Earth Orbit)通信星座的特殊功能决定了其构型优化需要综合考虑成本、覆盖和路由性能等因素.以往的研究往往忽略了路由性能,导致优化得到的构型不能很好的满足要求.首先给出了两个意义明确的星座路由性能的评价指标,然后通过将它们作为目标函数进行仿真,验证了其优化必要性和评价有效性.最后利用多目标遗传算法实现了星座的构型优化.仿真结果显示,将路由算法加入到星座的构型优化中,在仅对星座构型参数进行微调的前提下,不仅满足了成本、覆盖等基本要求,而且星座的路由性能大大提高.     

基于改进ADC法的雷达阵地现场优化效能评估

针对雷达阵地现场优化的特点,分析了对抗条件下战场环境对雷达阵地现场优化效能的影响,建立了雷达阵地现场优化效能的指标体系,提出了一种改进型ADC模型,并通过实例分析验证了该方法的正确性和有效性,为雷达装备阵地现场优化提供了一定的参考依据。     

提升编辑素质 提高高职学报质量

为解决高职学报自身的困难和问题。从提高编辑素质的角度出发,分析学报发展的趋向,发展好的学报一般都拥有一个高素质的编辑团队。学报主要是反映学校教学与科研成果的学术阵地,学报质量如何提高,这与编辑素质水平的提升息息相关。     

Strategy to search fragments from breakups in GEO

This paper proposes a strategy to search fragments from breakups in the Geosynchronous Earth Orbit (GEO) region based upon population prediction and motion prediction by means of ground-based optical observations. Breakup fragments have uncertainties in the states such as their position and motion, or even in their existence. Population prediction and motion prediction resolve those uncertainties. Population prediction evaluates the time-averaged distribution of fragments, whose position at a given time is unknown, in the celestial sphere. Motion prediction evaluates the expected motion of fragments appeared in image series acquired by a telescope’s CCD camera. This paper logically describes procedures of the search strategy, and provides mathematical expressions of population prediction and motion prediction. This paper also validates the search strategy via actual observations, in which a confirmed breakup in the GEO region is selected as a target. It is concluded that the proposed strategy is valid even for searching uncataloged fragments from breakups in the GEO region.     

Shape and motion estimate of LEO debris using light curves

We have derived a tri-axial ellipsoidal model of an LEO object, a Cosmos 2082 rocket body, including its rotational axis direction, rotation period, precession, and a compositional parameter, using only light curve data from an optical telescope. The brightness of the object was monitored for two days and least-squares fitting was used to determine these values. The derived axial ratios are 100:18:18, the coordinates of the rotational axis direction on the celestial sphere are R.A. = 305.8° and Dec. = 2.6°, and its observed average rotation period is 41 s. When precession is considered, its amplitude and precession period are 30.5° and 29.4 min. These results show that optical light curve data are sufficient to determine the shapes and the motions of LEO objects.     

Object image linking of earth orbiting objects in the presence of cosmics

In survey series of unknown Earth orbiting objects, no a priori orbital elements are available. In surveys of wide field telescopes possibly many non-resolved object images are present on the single frames of the series. Reliable methods have to be found to associate the object images stemming from the same object with each other, so-called linking. The presence of cosmic ray events, so-called Cosmics, complicates reliable linking of non-resolved images. The tracklets of object images allow to extract exact positions for a first orbit determination.     

现代酒店客房服务中存在的问题及对策

为有效提高酒店客房的服务质量。通过实地调查研究,发现现代酒店客房服务中存在的主要问题,并分析其原因,提出解决方法。这对酒店的可持续发展至关重要,有助于酒店形成人性化的服务特色,增加其市场竞争力和旅游吸引力。     

飞机价值最大化准则下的工程评估

在分析了航空公司工程评估面临的问题和难点的基础上,提出了飞机价值最大化的工程评估准则,建立了在这一准则下的工程评估体系,同时将实物期权理论引入了基于飞机价值最大化准则的工程评估,以实物期权价值计算方法替代了传统的净现值方法.