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1.
温玉全  张利敏  洪东跑 《兵工学报》2010,31(11):1498-1501
为了在较小样本量下验证高可靠性要求的火工品的发火可靠性,研究了火工品可靠性试验数据分析方法,提出了通过升降法试验估计感度分布参数,利用Bootstrap方法对感度分布参数中的刻度参数的估计进行修正,结合假设检验和抽样检验,在低刺激量点进行小样本试验验证高刺激量点的火工品发火可靠性的方法。大小样本对比试验表明使用该方法可以利用较少的试验样本量,实现对高可靠性要求的火工品的发火可靠性验证。  相似文献   

2.
基于序约束的火工品可靠性试验数据分析   总被引:3,自引:2,他引:1  
洪东跑  赵宇  温玉全 《含能材料》2008,16(5):556-559
为了能在较小样本量下提高火工品可靠性试验数据分析效果,研究了Langlie法试验,给出了火工品可靠性试验数据分析方法。该方法利用保序回归对Langlie法试验数据进行处理,给出参数的序约束估计。模拟结果表明基于序约束的Langlie试验数据的位置参数估计具有较优的统计性质。最后利用该方法对某针刺雷管进行可靠性评估,并与大样本方法比较,表明该方法可以利用65个样本在置信水平为0.9时对可靠性为0.999的火工品进行评估。  相似文献   

3.
可靠性的评定结果是否可信,直接关系到火工品的使用安全性和作用可靠性.现有火工品可靠性评定方法中较准确的是步进法,而最常用的是Bruceton升降法.本文假设样本总体符合不同分布的情况下设计升降法试验,通过试验得到的大量感度试验数据对这两种方法进行了比较,结果得知,在估计0.999响应点时,升降法比步进法乐观,刺激量比步进法平均低15%~25%;在以错误的样本总体分布设计升降法时,其产生的偏差更大.  相似文献   

4.
利用参数化方法估计火工品的发火可靠性时,标准差估计偏差常使评估结果冒进;通过非参数化方法估计火工品的发火可靠性时,试验样本量通常比较大。为解决以上问题,以应力-强度干涉模型为理论基础,将参数化评估方法和非参数化评估方法相结合,提出一种基于感度分布均值的火工品发火可靠性小样本评估方法。该方法只需利用感度分布均值就能在置信水平不变条件下,将工作刺激量处的验证试验转化为低刺激量处的验证试验,从而大大降低试验样本量。应用大样本的步进法和所提新方法对某型针刺雷管和某型电点火头进行对比验证试验。结果表明:两种方法的可靠性评估结果一致,所提小样本评估方法是合理的,可应用于机械火工品、电火工品的发火可靠性评估。  相似文献   

5.
基于时序模型的火工品贮存可靠性分析方法   总被引:1,自引:0,他引:1  
洪东跑  赵宇 《兵工学报》2009,30(12):1679-1683
火工品具有寿命长且可靠性高的特点,为了提高其贮存可靠性分析的精确性,研究了火工品及其贮存可靠性的特点,利用感度试验数据,给出了基于时序模型的火工品贮存可靠性分析方法。该方法利用升降法试验数据给出了感度分布参数的极大似然估计,并结合先验信息给出了刻度参数的收缩估计。数值模拟结果表明,在一定条件下,收缩估计具有更优的统计性质。采用时序模型来描述感度分布参数随贮存时间的变化趋势;结合分布参数的估计值给出了模型参数的最小二乘估计;然后利用该模型对分布参数进行外推。结合信仰推断方法,给出了火工品贮存可靠度置信下限。数值算例表明该方法合理、可行,可用于高可靠性火工品的贮存可靠性分析。  相似文献   

6.
洪东跑  赵宇  温玉全 《含能材料》2009,17(5):608-611
火工品属于一种长寿命且高可靠性的敏感性产品,为了提高其贮存可靠性评估精度,研究了火工品贮存可靠性的特点,给出了一种利用感度试验数据的火工品贮存可靠性分析方法。该方法利用升降法试验来获得感度分布参数的估计,并对参数估计进行了处理,使其满足一定序约束条件。结合该估计值,选取合适的模型来描述感度分布参数与贮存时间的关系,并对模型参数进行了统计推断。利用该模型,给出了贮存可靠性置信限和贮存寿命置信限。数值算例表明该方法可以用于高可靠性火工品的贮存可靠性评估与贮存寿命预测。  相似文献   

7.
为解决高发火可靠度火工品评估所需样本量过大的问题,基于信息量等值原理,提出了火工品较小样本量下的发火可靠性试验方法。该方法根据信息理论中信息量的定义,以火工品发火概率对数的负值度量其可靠性试验信息量,通过可靠性试验信息量等值方程,把按GJB376-1987评估需要在较高刺激量处进行较大样本量的试验转换为在较低刺激量处较小样本量的试验。采用该方法对应急开启系统中使用的火工品发火可靠性评估,在置信度不小于90%,发火可靠度大于0.999的前提下,所需样本量仅为22发,与GJB376-1987规定的用计数数据评估火工品发火可靠性所需样本量2 303发相比,极大地减少了样本使用量。试验表明,基于试验信息量等值原理的火工品发火可靠性小样本试验方法准确、可行,能够满足试验设计的目的。  相似文献   

8.
董海平  蔡瑞娇 《含能材料》2007,15(6):608-611
为了实现火工品高可靠性指标的小样本评估,研究了火工品可靠性评估小样本试验设计方案,给出了基于试验信息熵的小样本试验设计方法。采用该方法对用于H/DRl31引信头部击发机构的54号针刺雷管可靠性进行了试验与评估。结果表明,在试验刺激量4.5cm处试验22发产品,全部发火,评估结果与采用1800发大样本试验验证结果一致,该产品达到了置信水平为0.90,可靠度为0.999的可靠性指标。  相似文献   

9.
火工品发火可靠性小样本鉴定试验方法   总被引:1,自引:0,他引:1  
田玉斌  王典鹏 《兵工学报》2011,32(4):426-431
针对火工品的高发火可靠性指标(可靠度下限p,置信水平1-α),基于估计100%p发火点的小样本优化试验设计,给出100%p发火点的置信上限、鉴定火工品可靠性的方法以及火工品作用裕度的区间估计.模拟研究表明,利用优化试验设计估计火工品的100%p发火点,样本量小,精确度高;利用优化试验设计鉴定火工品的发火可靠性,样本量小...  相似文献   

10.
采用Monte Carlo方法研究了GJB376规定的用计数数据估计火工品可靠度的方法和已建立的计量-计数评估方法在试验方面的等效性,根据评定准则采用这两种方法判定试验结果合格的接收率最大误差小于1%。对20种不同类型的火工品及两种人为设定为不合格产品,采用计量-计数法和步进法进行了对比试验研究,两种方法得到的可靠性评估结果一致。分析结果表明,计量-计数评估方法与GJB376规定的用计数数据估计火工品可靠度的方法等效,工程应用可行,对评估高可靠性的火工品,能大幅度降低样本量。  相似文献   

11.
Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.  相似文献   

12.
The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS (geographical information system) data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.  相似文献   

13.
By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.  相似文献   

14.
The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.  相似文献   

15.
An expression for estimating the aeroheating on a warhead nose at different supersonic speeds is proposed by incorporating CFD (computational fluid dynamics) and the least-square method. Compared with the traditional estimation formula, the expression is more accurate, convenient and can be used in the optimized design of warheads. The error from the result obtained in the test of a ball cartridge flight is less than 3 %. It satisfies the engineering requirements.  相似文献   

16.
The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent "explosion of terms". Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.  相似文献   

17.
For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.  相似文献   

18.
Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.  相似文献   

19.
阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅(LTNR)的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明:一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。  相似文献   

20.
By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux (kernel version 2.6.11 ) is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.  相似文献   

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