共查询到18条相似文献,搜索用时 78 毫秒
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靶场观测中存在大量不发光和表面温度接近常温的低温目标,根据它们的光谱辐射特性、背景辐射特性和大气透过率与目标距离的关系,分别选择了中波和长波红外探测器对降落伞进行气球放飞试验。试验结果表明,长波红外探测器对常温目标的探测要优于中波红外。选择分辨力320×256 的碲镉汞探测器作探测能力实验,以 SNR≥5 为可探测条件,当目标表面温度大于 260K时,对直径 5m 的降落伞的作用距离可达 50Km。 相似文献
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由电子41所研制的红外焦平面阵列相对光谱响应测试系统采用单光路标准替代法进行测量,系统组成灵活并可扩展,配合自行研制的图形发生器,偏置,时钟驱动、数据采集子系统,可以满足不同被测器件的需要。 相似文献
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提高电视跟踪系统作用距离的方法探讨 总被引:2,自引:0,他引:2
本文从影响电视跟踪系统作用距离的因素:目标大小、对比度、背景以及信噪比出发,总结了作者多年来在提高电视跟踪系统作用距离方面所做的工作。除此之外,作者还提出了一些新颖的提高电视跟踪系统作用距离的方法。 相似文献
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给出了红外警戒系统点目标探测距离的计算模型与公式,分析了影响点目标探测距离的参数间关系,并得出有关目标提取算法及传感器参数选择的几点重要结论。 相似文献
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应用于弹丸跟踪测量的红外器件工作波段选择 总被引:4,自引:0,他引:4
目的:探讨利用红外焦平面热像仪对常规快速弹丸目标进行跟踪与测量,以提高对弹丸目标的跟踪测量能力。方法:对靶场试验中常用弹丸目标的光谱辐射特性,背景辐射特性以及大气透过率进行了综合理论分析,并在理论分析的基础上结合试验结果进行分析,结果:对工作波段3um-5um,8um-12um的红外焦平面热像仪以及可见光电视的探测能力进行了比较。结论:响应工作波段为3um-5um的红外热像仪最适于作常规弹丸目标的跟踪测量设备。 相似文献
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介绍一种实际使用的小型跟踪测量电视系统 ,它通过提高光学系统透过率和增强图象对比度 ,以及采用数字背景拟合自适应电平检测的方法 ,达到远距离探测目标的任务。 相似文献
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根据列车-轨道系统运动的特点,提出了适合该问题动力学分析的新型车辆单元和轨道单元,运用有限元方法和Lagrange方程,推导了两种单元的刚度矩阵、质量矩阵和阻尼矩阵。整个列车-轨道系统只需离散成车辆单元和轨道单元,其中轨道系统离散成轨道单元,一节车辆离散成一个车辆单元。该模型具有程序编制容易、计算效率高的特点。作为应用实例,给出单轮通过和考虑轨道完全平顺和具有随机不平顺条件下整车通过时车辆和轨道动力响应分析的二个算例。 相似文献
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Nong Ye 《国际生产研究杂志》2017,55(3):828-844
Although having structural system models which determine system behaviours is critical to plan, control and manage many complex systems (e.g. manufacturing and production systems), we often do not have pre-defined structural system models. We need to perform reverse engineering which is to collect and mine observable system data in order to discover structural system models. This paper presents a reverse engineering algorithm that can be used to discover a causal system model which is one kind of structural system model and represents causal relations of system factors. In a causal relation, the presence of one system factor causes the presence of another system factor. The paper also shows the computational complexity of the algorithm. The paper presents the application and performance of the reverse engineering algorithms to data in two application fields. 相似文献
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In this article, we discuss the problem of computing the unavailability of a multistate-component system. We propose the use of a Boolean model describing as much as possible about the system structure. A theorem of two-sided estimation of the approximation error enables us to check the calculation accuracy. An application of this method to a nuclear safety system is offered. 相似文献
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Christine M. Samaniego-Esguerra Gordon L. Robertson 《Packaging Technology and Science》1991,4(2):61-68
The water vapour permeability constants of three flexible films (LDPE, PET and a laminate of both films) were determined at 20, 30 and 40 °C and from 55 to 90% relative humidities. The relationship between permeability and temperature followed the Arrhenius model for the three films. The relative humidity also influenced the permeability of the films. A mathematical model describing permeance (P/X - the permeability of laminates or films) as a function of external relative humidity and temperature was developed. The model can be used to predict the permeance of the three films at different temperatures and relative humidities. 相似文献
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A mathematical model, proposed for simulation of food refrigeration processes, was tested against experimental data collected in a New Zealand meat processing plant which had a total refrigeration capacity of 2.5 MW. Predicted air temperatures in freezing and chilling operations followed the same trends as measured data. Differences were shown to be more attributable to uncertainties in data than to deficiencies in the formulation of the mathematical model. The model is considered suitable for use in simulation of a wide range of food refrigeration processes. Such simulations provide useful information about plant performance that cannot be obtained by steady state analysis. Predictions were worst for short times immediately following step changes in plant operation; should more accurate simulation of these periods be required a different form of mathematical model is needed. 相似文献
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N. A. Parfent’ev 《Measurement Techniques》2007,50(9):975-978
The stability of a multiloop system for controlling a highly accurate radiator is analyzed.
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Translated from Izmeritel’naya Tekhnika No. 9, pp. 42–44, September, 2007. 相似文献
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The operation safety of depressurizing a high-pressure gas-filled vessel is of crucial importance in petroleum, chemical and biological processing industries. The present study describes a simple model of a slow depressurization process and derives its analytical solution in a recurrence form. This analytical solution is expected to be useful for engineering applications and for the assessment of either detailed numerical simulations or experimental data. 相似文献