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The evaluation index of camouflage patterns is important in the field of military application. It is the goal that researchers have always pursued to make the computable evaluation indicators more in line with the human visual mechanism. In order to make the evaluation method more computationally intelligent, a Multi-Feature Camouflage Fused Index (MF-CFI) is proposed based on the comparison of grayscale, color and texture features between the target and the background. In order to verify the effectiveness of the proposed index, eye movement experiments are conducted to compare the proposed index with existing indexes including Universal Image Quality Index (UIQI), Camouflage Similarity Index (CSI) and Structural Similarity (SSIM). Twenty-four different simulated targets are designed in a grassland background, 28 observers participate in the experiment and record the eye movement data during the observation process. The results show that the highest Pearson correlation coefficient is observed between MF-CFI and the eye movement data, both in the designed digital camouflage patterns and large-spot camouflage patterns. Since MF-CFI is more in line with the detection law of camouflage targets in human visual perception, the proposed index can be used for the comparison and parameter optimization of camouflage design algorithms. 相似文献
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In order to predict the storage life of a certain type of HTPB (hydroyl-terminated polybutadiene) coating at 25 C and analyze the influence of pre-strain on the storage life, the accelerated aging tests of HTPB coating at 40 C, 50 C, 60 C, 70 C with the pre-strain of 0%, 3%, 6%, 9%, respectively were carried out. The variation regularity of the change of crosslinking density was analyzed and the aging model of HTPB coating under pre-strained thermally-accelerated aging was proposed. The storage life of HTPB coating at 25 C was estimated by using the Berthelot equation as the end point of the aging life with a 30% decrease in maximum elongation. The results showed that the change of crosslinking density of HTPB coating increased with the increase of aging temperature and aging time, and decreased with the in-crease of pre-strain. Under 0% pre-strain, the relationship between the change of crosslinking density of HTPB coating and the aging time can be described by the logarithmic model with the confidence probability greater than 99%.The stress relaxation phenomenon existed under 3%, 6% and 9% pre-strained aging. The aging model considering chemical aging and pre-strain was established with the confidence probability greater than 90%. The storage life of HTPB coating was 15.2935 years at 25 C under 0% pre-strain, which was reduced by 13.9007%, 75.6949% and 89.7859% under 3%, 6% and 9% pre-strain, respectively. The existence of pre-strain has a serious impact on the storage life of HTPB coating, therefore, the pre-strain should be avoided as much as possible during the actual storage. 相似文献
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针对中国近海海空联合作战环境风险区划问题,选取水面舰艇航行、舰载机飞行、海上人员训练等作战样式,大风、大浪、低云低能见度、湿热、风寒等环境要素,高值频率、概率极值、平均强度、气候趋势等指标,利用层次分析法和互反判断矩阵建立四层评价体系并进行区划.该方法可根据装备设计及环境适应标准对各指标进行影响排序,能有效区分不同季节和动力机制的环境要素差异、综合考虑不同类型风险影响.区划结果证明,海空联合作战环境风险由各兵种作战风险综合决定,主要受秋冬季盛行大风、夏秋季热带气旋、春夏季低能见度、冬春夏季低云、夏季湿热指数、冬季风寒指数等影响. 相似文献
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Studies on ballistic penetration to laminates is complicated, but important for design effective protection of structures. Experimental means of study is expensive and can often be dangerous. Numerical simu-lation has been an excellent supplement, but the computation is time-consuming. Main aim of this thesis was to develop and test an effective tool for real-time prediction of projectile penetrations to laminates by training a neural network and a decision tree regression model. A large number of finite element models were developed;the residual velocities of projectiles fromfinite element simulations were used as the target data and processed to produce sufficient number of training samples. Study focused on steel 4340tpolyurea laminates with various configurations. Four different 3D shapes of the projectiles were modeled and used in the training. The trained neural network and decision tree model was tested using independently generated test samples using finite element models. The predicted projectile velocity values using the trained machine learning models are then compared with thefinite element simulation to verify the effectiveness of the models. Additionally, both models were trained using a published experimental data of projectile impacts to predict residual velocity of projectiles for the unseen samples. Performance of both the models was evaluated and compared. Models trained with Finite element simulation data samples were found capable to give more accurate predication, compared to the models trained with experimental data, becausefinite element modeling can generate much larger training set, and thus finite element solvers can serve as an excellent teacher. This study also showed that neural network model performs better with small experimental dataset compared to decision tree regression model. 相似文献
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超音速等离子喷涂WC-Co涂层性能研究 总被引:4,自引:0,他引:4
用超音速等离子喷涂(HEPJet)和2种进口高速氧燃气火焰喷涂设备 (HVOF:JP-5000和DJ-2700)制备WC-Co涂层,进行了孔隙率、显微硬度、结合强度及30°和90°攻角的冲蚀磨损对比试验,用XRD分析了粉末和涂层的相结构,用 SEM分析了粉末和涂层的表面和断面形貌。结果表明3种工艺制备的WC-Co涂层与粉末的相结构类似,均无明显氧化、失碳;超音速等离子喷涂WC-Co涂层综合性能与JP-5000相当,要优于DJ-2700。 相似文献
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针对信息化条件下陆军防空兵体制编制的主要特点和发展趋势,研究了如何定量评估其信息化程度问题。运用模糊综合评判法和综合评分分析法建立了防空兵体制编制信息化评估模型。并以某防空旅为例进行了实例测评,基本上反映了该旅体制编制信息化建设的真实水平,证明建立的模型是可行和正确的。而且,通过对不同元素测评结果的对比分析,可以清楚地看出测评对象体制编制各元素信息化建设的发展态势,找出下一步建设的努力方向。 相似文献
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单[6-脱氧(1,10癸二硫醇)巯基]β-环糊精的合成方法研究 总被引:1,自引:0,他引:1
制备合成单[6-脱氧(1,10癸二硫醇)巯基]β-环糊精,结合产物的。^1H NMR,^13C HMR分析,推测了可能的反应机理,初步讨论了其在制备传感器敏感膜材料方面的应用前景。 相似文献