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131.
四轮转向汽车路径跟随控制 总被引:1,自引:0,他引:1
路径跟随控制是汽车实现自动驾驶的重要工具,已在前轮转向汽车上取得了较好的效果,但是前轮转向汽车的路径跟随控制不完全适用于四轮转向汽车.对此,基于横向误差,提出一种四轮转向汽车路径跟随模糊控制算法.首先,建立响应面模型作为优化目标函数.然后,利用遗传算法对模糊控制器进行优化设计.最后,通过Carsim-Simulink联合仿真实验,对该算法进行验证.仿真结果表明,路径跟随横向误差得到有效降低,车身质心侧偏角也控制在0.6°以内.该算法能够实现精准的路径跟随,并提高汽车的操纵稳定性. 相似文献
132.
跨境电商人才校企协同育人模式探析 总被引:1,自引:0,他引:1
针对跨境电商飞速发展导致人才缺口持续加大的问题,提出跨境电商人才需要具备外语交流、外贸实务、网络技术、国际物流和跨文化沟通等五个方面的素质,认为校企协同育人应是跨境电商人才培养的首选模式。构建了校企合作指导跨境电商实习、依托企业以赛促练、学生代理企业产品和共建跨境电商人才培养的课程体系。 相似文献
133.
图像质量评价是利用计算机模拟人类视觉系统自动评价图像的失真程度,而图像美学质量评价是利用计算机模拟人类对美的感知与认知,自动评价图像的"美感",分析图像在构图、颜色、光影、景深、虚实等美学因素影响下所形成的美感刺激,这是计算美学与计算机视觉、心理学、虚拟现实等领域的学科交叉新方向,其在摄影摄像、电影电视、电子商务、服装设计、平面设计、文稿设计、工业设计、汽车行业、建筑行业、美容美妆等多个行业具有良好的应用前景。本文回顾了图像美学质量评价的发展历史,从基于人工设计美学特征的方法、基于美学特征深度学习的方法、图像美学质量评价的新任务、图像美学质量评价数据集构建等方面综述了该领域关键技术的发展情况,并展望了图像美学质量评价及其关键技术的发展趋势。 相似文献
134.
Gen Liu Xue Yu Rui Xu Xiaodong Zhu Yanqing Ma Prof. Lei Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(70):17620-17627
Chemical bath deposition method has been used to synthesize a variety of ZnO morphology structures. However, the specificity and interaction of acetate and ammonium ions with ZnO crystal during the growth process remain elusive. This study contributes to understand the roles of ammonium acetate on the growth mechanism of ZnO in Zn(NO3)2-HMTA system. The growth process indicates that the nucleation experienced Zn2+-layered basic zinc salts (LBZs)-ZnO process, while the self-assembled unit changed from urchin-shaped, rod-shaped to a fully coupled twin-shaped structure with increasing ammonium acetate concentration. Ammonium acetate dominates the growth process by combing the ligand-ligand interaction of acetate ions binding to the same Zn-rich (0001) polar surface and ammonium ions regulating hexamethylenetetramine (HMTA) hydrolysis. Relatively regular hexagonal wurtzite structure and a dissolve-renucleation-regrowth process which retains the twin-shaped template and renucleates at the same position are observed at ∼10 mM ammonium acetate. Photoelectrochemistry (PEC) measurements show that the uniform hexagonal ZnO rods (Y-10, the sample named as Y-x (x represents x mM ammonium acetate, herein, x is 10 mM)) have a maximum photocurrent density of 1.54 mA cm−2 at 1.23 V (vs. RHE), much higher than that of the dumbbell-shaped ZnO rods (Y-50, 0.20 mA cm−2) at the same voltage. These results provide a further explanation of morphology regulation mechanisms on ZnO synthesis processes and pave the road for more practical applications. 相似文献
135.
CO and formaldehyde(HCHO)oxidation reactions were investigated over mesoporous Ag/Co3O4 catalysts prepared by one-pot(OP)and impregnation(IM)methods.It was found that the one-pot method was superior to the impregnation method for synthesizing Ag/Co3O4 catalysts with high activity for both reactions.It was also found that the catalytic behavior of mesoporous Co3O4 and Ag/Co3O4 catalysts for the both reactions was different.And the addition of silver on mesoporous Co3O4 did not always enhance the catalytic activity of final catalyst for CO oxidation at room temperature(20 C),but could significantly improve the catalytic activity of final catalyst for HCHO oxidation at low temperature(90 C).The high surface area,uniform pore structure and the pretty good dispersion degree of the silver particle should be responsible for the excellent low-temperature CO oxidation activity.However,for HCHO oxidation,the addition of silver played an important role in the activity enhancement.And the silver particle size and the reducibility of Co3O4 should be indispensable for the high activity of HCHO oxidation at low temperature. 相似文献
136.
137.
Liu Zhenhong Li Xiaodong Liu Xiaoping 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1701-1706
Journal of Radioanalytical and Nuclear Chemistry - An indicator with double tracers has been developed so as to improve the accuracy and stability of quantitative analysis of renal injury. The... 相似文献
138.
提出了基于数学形态学和纹理特征的快速定位车牌的方法.该方法包含4个步骤:预处理,利用Sobel算子进行垂直边缘检测,通过形态学操作得到连通域,利用车牌的纹理特征和字符特征最终定位车牌.使用该方法对1 144幅图片进行实测,1 102幅图片定位成功,正确识别率为96.3%,处理时间为160~200ms. 相似文献
139.
通过对在校电子商务专业大学生进行问卷调查,分别从个人能力、货源问题、淘宝规则和创业环境几个角度对大学生淘宝创业现状进行分析,指出应通过加强大学生网上创业意识的培养、增加校企合作、充分利用政策支持和熟悉淘宝规则等方面推动大学生淘宝创业。 相似文献
140.
Hydrogels containing hyper-branched poly(amidoamine) (hb-PAMAM) microenvironments were suggested for the sustained release of ionizable drugs. For this purpose, a series of poly(2-hydroxyethyl acrylate) (PHEA) hydrogels containing hb-PAMAM (PHEA-hb-PAMAM) were prepared by copolymerization of 2-hydroxyethyl acrylate with acryl-terminated hb-PAMAM. The hb-PAMAM was synthesized by the Michael addition reaction of triacryloylhexahydro-1,3,5-triazine (TT) and piperzaine (PZ). By using nonionic Tegafur and ionizable salicylic acid (SA) as model drugs, the release mechanisms of drugs from PHEA-hb-PAMAM hydrogels were investigated. Compared with the release kinetic of Tegafur, the release rate of SA from the hydrogels was evidently slowed down. Moreover, the release rate of SA can be modulated by the addition of salt. This can be attributed to the ionic interaction of SA with hb-PAMAM microenvironments. By analyzing the release kinetics of SA from the hydrogels, it was found that the release of SA followed non-Fickian diffusion. 相似文献