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Jordi Molas‐Gallart 《Defence and Peace Economics》2013,24(2):141-158
It is often stated that technological change in the military field is characterised by the introduction of radical innovations rather than by incremental processes of technological change. This article illustrates the diversity of military innovation by arguing that technological change in missiles systems is dominated by incremental change. While some large weapons platforms display the design rigidities normally associated with complex systems, missiles are characterised by “flexible modularity”. Flexible modularity facilitates the continuous introduction of upgrades, and makes missile systems amenable to gradual technological change. Besides, it has significant implications for the future role of missile systems, and poses special problems for missile disarmament and technology control initiatives. 相似文献
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In discussing China's January 2007 hit-to-kill intercept of the Chinese weather satellite FengYun-1C, most American analysts sought the “message” for the United States—either by asserting that China's test was a deliberate step toward a comprehensive counterspace capability to offset U.S. conventional military superiority or an attempt to force the United States to the negotiating table on “the prevention of an arms race in outer space.” Chinese officials, after a long silence, eventually claimed the test was an “experiment” that was “not targeted at any country.” We traveled to China several times in 2007 and had a series of conversations with Chinese individuals knowledgeable about the history of this particular antisatellite program and with access to information about the decision-making process prior to and after the final test. These discussions were off the record, not for attribution, given the sensitivity of the subject. They reflected the views of some of the key institutions involved in the test from the State, the Communist Party, the People's Liberation Army, and aerospace experts involved in debris calculations. The information conveyed to us suggests that American commentators tend to place much greater importance on the United States as a driver in China's decision to develop the technology and conduct the test than do the Chinese. 相似文献
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舰空导弹武器系统抗击能力通常会随着舰空导弹单次射击而发生变化,为增强舰空导弹武器系统抗击能力评估方法的实用性,提出了一种新的舰空导弹武器系统抗击能力评估方法,进而构建了舰空导弹单次射击能力评估方法。算例证明,本文提供的方法可以有效评定单艘水面舰艇上单个舰空导弹武器系统在作战使用环境下的抗击能力。 相似文献
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针对无人机对地目标识别过程中的小样本问题以及目标存在的遮挡和混淆情况,提出了一种融合自注意力机制的小样本目标识别模型。在利用元学习思想获取小样本学习能力的基础上,将自注意力机制学习目标内部各部分之间的上下文依赖关系引入模型,从而增强目标表征能力,以解决遮挡和混淆情况下有效特征不足的难题。为验证模型效果,通过对基准数据集和无人机航拍数据进一步加工,构建了遮挡和混淆目标数据集,设置了不同的遮挡程度和背景混淆率。通过在不同数据集上的验证,并与深度学习模型对比,证明提出的模型具有更高的学习效率和识别正确率。 相似文献
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《防务技术》2022,18(9):1589-1601
Infrared (IR) small target detection is one of the key technologies of infrared search and track (IRST) systems. Existing methods have some limitations in detection performance, especially when the target size is irregular or the background is complex. In this paper, we propose a pixel-level local contrast measure (PLLCM), which can subdivide small targets and backgrounds at pixel level simultaneously. With pixel-level segmentation, the difference between the target and the background becomes more obvious, which helps to improve the detection performance. First, we design a multiscale sliding window to quickly extract candidate target pixels. Then, a local window based on random walker (RW) is designed for pixel-level target segmentation. After that, PLLCM incorporating probability weights and scale constraints is proposed to accurately measure local contrast and suppress various types of background interference. Finally, an adaptive threshold operation is applied to separate the target from the PLLCM enhanced map. Experimental results show that the proposed method has a higher detection rate and a lower false alarm rate than the baseline algorithms, while achieving a high speed. 相似文献