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31.
Hopfield和Tank证明几种最优化问题能用Hopfield网络快速求解,而Hopfield网络是简单的类似神经元模拟处理机的递推网络。使用Hopfield网络时,目标函数的自变量收敛于超立方体的顶点。因此,它们的应用严格地限于决策最优化问题。在本文中,我们将研究目标函数自变量是实数的问题。基于Hopfield网络的概念,推导了求解最小二乘估计问题的神经网络。用这个网络,目标函数可能收敛于超立方体内的任何点,给出一个具有极大速度的实值解。由于所选择的能量函数的凸状性质,不会出现收敛到局部最小值的问题。我们还介绍了空间迭代搜索方法,以便找到可能存在于空间内任意点的最优解。最后,给出了求解线性系统和参数估计问题的模拟结果。 相似文献
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In order to examine the possibility to improve its camouflage properties standard cotton fabric with camouflage print was impregnated with poly(vinyl butyral), PVB and fullerene-like nanoparticles of tungsten disulfide, PVB/IF-WS2. FTIR analysis excluded any possible chemical interaction of IF-WS2 with PVB and the fabric. The camouflage behavior of the impregnated fabric has been examined firstly in the VIS part of the spectrum. Diffuse reflection, specular gloss and color coordinates were measured for three different shades (black, brown and dark green). Thermal imaging was applied to examine the camouflage abilities of this impregnation in IR part of the spectrum. The obtained results show that PVB/IF-WS2 impregnation system induced enhacement of the materials camouflage properties, i.e. that IF-WS2 have a positive effect on spectrophotometric characteristics of the fabric. 相似文献
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Joanna R.Hall Olivia Matthews Timothy N.Volonakis Eric Liggins Karl P.Lymer Roland Baddeley Innes C.Cuthill Nicholas E.Scott-Samuel 《防务技术》2021,17(6):1833-1839
The human visual system is still an important factor in military warfare; military personnel receive training on effective search strategies, and camouflage that can effectively conceal objects and personnel is a key component of a successful integrated survivability strategy. Previous methods of camouflage assessment have, amongst others, used psychophysics to generate distinctiveness metrics. However, the population from which the human observers are drawn is often not well defined, or necessarily appropriate. In this experiment we designed a new platform for testing multiple patterns based on a camouflaged object detection task, and investigate whether trained military observers perform better than civilians. We use a two-alternative forced choice paradigm, with participants searching images of woodland for a replica military helmet displaying Olive Green, Multi Terrain Pattern, US Marine Pattern or, as a conspicuous control, UN Peacekeeper Blue. Our data show that there is no difference in detection performance between the two observer groups but that there are clear differences in the effectiveness of the different helmet colour patterns in a temperate woodland environment. We conclude that when tasks involve very short stimulus presentation times, task-specific training has little effect on the success of target detection and thus this paradigm is particularly suitable for robust estimates of camouflage efficacy. 相似文献
34.
第二次世界大战后,美苏展开了长达40余年的冷战,以核武器为重要标志的军备竞赛,如同“达摩克利斯之剑”,将全世界都笼罩在“第三次世界大战”、“核冬天”的阴影之下。1950年1月,美国总统杜鲁门作出研发氢弹的决定,成为一项在整个冷战期间具有里程碑意义的战略决策。 相似文献
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“阿尔·里雅德”号隐形护卫舰(AL RIYADH舷号812)是法国海军拉斐特级隐形护卫舰的改进型,由法国海军舰船制造局洛里昂造船厂建造,型号名称F-3000S,2001年9月17日首次海上试航。该舰满载排水量4650吨(比原型舰多950吨),全长135米,两座燃气轮机驱动,主机20.6兆瓦,最大航速25节。该照片为舰艏部特写。 相似文献
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早期历史作为英国国防政策的一部分,英国政府对北约欧洲中部前线承担义务。在战时,平时驻扎在那里的55000名士兵的部队将得到另外62000名来自英国本土正规军和国防军(TA)的增援。这些部队大部分来自于防空部队,这些防空部队不管它是属于正规军还是属于国防军都隶属于皇家炮兵团,受军团防空部门(CADC)统一指挥并统一采用1军团的指挥、控制和通讯(C~3)方式。防空部队的任务是防止敌方飞机干扰己方地面部队作战的实施。这种把 相似文献
39.
Person-borne improvised explosive devices (PBIEDs) are often used in terrorist attacks in Western countries. This study aims to predict the trajectories of PBIED fragments and the subsequent safety risks for people exposed to this hazard. An explosive field test with a typical PBIED composed of a plastic explosive charge and steel nut enhancements was performed to record initial fragment behaviour, including positions, velocity, and trajectory angles. These data were used to predict the full trajectory of PBIED fragments using a probabilistic analysis. In the probabilistic analyses a probability of fatality or serious injury was computed. Based on the results presented, many practical conclusions can be drawn, for instance, regarding safe evacuation distances if a person were exposed to a suspected PBIED. 相似文献
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