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Research on extraction and reproduction of deformation camouflage spot based on generative adversarial network model 被引量:5
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作者 Xin Yang Wei-dong Xu +4 位作者 Qi Jia Ling Li Wan-nian Zhu Ji-yao Tian Hao Xu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第3期555-563,共9页
The method of describing deformation camouflage spots based on feature space has some shortcomings,such as inaccurate description and difficult reproduction.Depending on the strong fitting ability of the generative ad... The method of describing deformation camouflage spots based on feature space has some shortcomings,such as inaccurate description and difficult reproduction.Depending on the strong fitting ability of the generative adversarial network model,the distribution of deformation camouflage spot pattern can be directly fitted,thus simplifying the process of spot extraction and reproduction.The requirements of background spot extraction are analyzed theoretically.The calculation formula of limiting the range of image spot pixels is given and two kinds of spot data sets,forestland and snowfield,are established.Spot feature is decomposed into shape,size and color features,and a GAN(Generative Adversarial Network)framework is established.The effects of different loss functions on network training results are analyzed in the experiment.In the meantime,when the input dimension of generator network is 128,the balance between sample diversity and quality can be achieved.The effects of sample generation are investigated in two aspects.Subjectively,the probability of the generated spots being distinguished in the background is counted,and the results are all less than 20% and mostly close to zero.Objectively,the features of the spot shape are calculated and the independent sample T-test is applied to verify that the features are from the same distribution,and all the P-Values are much higher than 0.05.Both subjective and objective methods prove that the spots generated by this method are similar to the background spots.The proposed method can directly generate the desired camouflage pattern spots,which provides a new technical method for the deformation camouflage pattern design and camouflage effect evaluation. 展开更多
关键词 Deformation camouflage Generative adversarial network Spot feature Shape description
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更快速度下周期性短波不平顺引起的轮轨高频振动特性及控制限值
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作者 张航 卢春房 +2 位作者 高亮 杨飞 孙加林 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第5期1700-1710,共11页
随着列车运行速度的不断加快,轮轨高频振动引起的车辆、轨道部件伤损问题更加突出,尤以周期性的短波不平顺最为常见。为了掌握轮轨高频振动自下而上的传递衰减规律以及制定合理的钢轨打磨策略,有必要针对车辆系统在高频激励条件下的耦... 随着列车运行速度的不断加快,轮轨高频振动引起的车辆、轨道部件伤损问题更加突出,尤以周期性的短波不平顺最为常见。为了掌握轮轨高频振动自下而上的传递衰减规律以及制定合理的钢轨打磨策略,有必要针对车辆系统在高频激励条件下的耦合振动特性开展深入的理论研究。本文通过对大量实测数据的拟合,得到了更宽频段范围内的轨道高低不平顺谱拟合公式,并通过反演得到了0.002~100 m波长范围内的高低不平顺样本;在此基础上建立了高速动车组-轨道刚柔耦合动力学模型,其中对轮对、钢轨均考虑了弹性体振动模态,仿真分析了周期性短波不平顺引起的轮轨高频振动特性。结果表明,车辆各部件的振动频率分布范围为30~1390 Hz,且自下至上呈逐层衰减趋势。通过提取周期性短波不平顺幅值变化对轮轨相互作用的影响规律,进一步提出了适应400 km/h高速铁路的典型波长周期性短波不平顺的量化控制限值要求。 展开更多
关键词 高速铁路 短波不平顺 全波段高低不平顺 车辆动力学响应 功率谱密度
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Using genetic algorithm based fuzzy adaptive resonance theory for clustering analysis 被引量:3
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作者 LIU Bo WANG Yong WANG Hong-jian 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2006年第B07期547-551,共5页
关键词 聚类分析 遗传算法 模糊自适应谐振理论 人工神经网络
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Corrosion behavior of 907 steel under thin electrolyte layers of artificial seawater 被引量:7
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作者 王慧萍 丁少春 +3 位作者 朱娟 张昭 张鉴清 曹楚南 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第3期806-814,共9页
The corrosion behavior of 907 steel under thin electrolyte layer(TEL) has been investigated by means of cathodic polarization curve measurement, electrochemical impedance spectroscopy(EIS) and scanning electron micros... The corrosion behavior of 907 steel under thin electrolyte layer(TEL) has been investigated by means of cathodic polarization curve measurement, electrochemical impedance spectroscopy(EIS) and scanning electron microscopy(SEM). The results show that the cathodic diffusion current density presents the variation trend of initial increase and subsequent decrease with the decrease of TEL thickness, and the maximum deposits at 58 μm. The cotangent-hyperbolic impedance(O) is rationally first introduced to study the diffusion process of the reactants through the corrosion products layer with many permeable holes. The initial corrosion rate of 907 steel under different TEL thickness increases with the decrease of TEL thickness except that of 104 μm,whereas the corrosion rate after long time corrosion can be ranked as 104 μm﹥402 μm﹥198 μm﹥301 μm﹥bulk solution. 展开更多
关键词 907 steel atmospheric corrosion electrochemical impedance spectroscopy polarization
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FRP加强R/C梁防火性能调查研究(英文) 被引量:2
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作者 BREA WILLIAMS LUKE BISBY +2 位作者 VENKATESH KODUR JOSEPH SU MARK GREEN 《消防科学与技术》 CAS 2007年第5期492-499,共8页
对纤维加强聚合物(FRP)材料加强钢筋混凝土梁在火灾中的防火性能进行了研究。试验结果显示,防火材料能够帮助构件达到标准防火性能,同时对不断增长的FRP应用也很重要。介绍了不同文献对FRP在高温下的性能所做的研究以及目前标准对建筑... 对纤维加强聚合物(FRP)材料加强钢筋混凝土梁在火灾中的防火性能进行了研究。试验结果显示,防火材料能够帮助构件达到标准防火性能,同时对不断增长的FRP应用也很重要。介绍了不同文献对FRP在高温下的性能所做的研究以及目前标准对建筑构件的耐火极限要求。对两个大型试验进行了介绍。试验材料为混凝土梁构件,外部用FRP板加强,并且三分之二用专利耐火隔热材料保护。给出了试验结果,并重点强调了曝火状态下所测得的构件温度。试验数据验证了热传导数值模型,该模型可用于预测加强并绝缘钢筋混凝土梁构件内的温度。试验结果和模型数据显示,正确设计和进行绝缘保护的FRP加强梁构件耐火极限能够达到4h或者以上。 展开更多
关键词 纤维加强聚合物(FRP) 时间温度标准曲线 数值模拟 耐火极限
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Formal Specifications and Verification of a Secure Communication Protocol Model 被引量:2
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作者 夏阳 陆余良 蒋凡 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2003年第2期90-97,共8页
This paper presents a secure communication protocol model-EABM, by which network security communication can be realized easily and efficiently. First, the paper gives a thorough analysis of the protocol system, system... This paper presents a secure communication protocol model-EABM, by which network security communication can be realized easily and efficiently. First, the paper gives a thorough analysis of the protocol system, systematic construction and state transition of EABM. Then , it describes the channels and the process of state transition of EABM in terms of ESTELLE. At last, it offers a verification of the accuracy of the EABM model. 展开更多
关键词 Protocol Model ESTELLE Extended alternating bit machine.
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Performance analysis of optical burst switching node with limited wavelength conversion capabilities 被引量:1
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作者 许毅 史开源 范戈 《Journal of Central South University》 SCIE EI CAS 2009年第5期794-801,共8页
The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . T... The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones. 展开更多
关键词 optical burst switching (OBS) limited range wavelength conversion (LRWC) wavelength converter burst contention burst loss probability
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On the Life and Political Ideals of the Poet Qu Yuan
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作者 Xiong Maosong 《学术界》 CSSCI 北大核心 2015年第4期303-307,共5页
Qu Yuan is one of the famous patriotic poets in the history of China,and as for his poems,they shall not only be interpreted from the literary perspective but also from the political perspective,because it is a tradit... Qu Yuan is one of the famous patriotic poets in the history of China,and as for his poems,they shall not only be interpreted from the literary perspective but also from the political perspective,because it is a tradition that poets tend to express their am bition through poems. In the poems of Qu Yuan,we can read both the thoughts about the country and about his own life. The ideal personality and the ideal politics are inseparable,the former of which is the foundation while the later the supreme goal. The integration of the ideal personality and the ideal politics is the essence of the patriotism of Qu Yuan,which,for the later generations,is still worthem phasizing and researching. 展开更多
关键词 理想 政治 屈原 诗人 生活 中国历史 爱国主义 人格
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