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61.
交通信号灯识别包括检测和状态识别,在智能交通系统中发挥重要作用。基于YOLOv3算法提出了一种交通信号灯检测与状态识别模型。针对交通信号灯相较于交通场景中其他目标具有尺度小的特性进行了算法的设计:降低骨干网络的下采样倍率以增加小尺度目标的特征描述能力;通过增大特征图的尺度来改进多尺度特征融合;引入广义交并比作为检测任务的损失函数来改进目标边界框的回归效果。同时,根据交通信号灯本身的特性,使用颜色和形状约束的方法对信号灯进行状态识别和类别验证。最后在公开的Bosch交通信号灯数据集上和实际的城区道路进行了实验验证。实验结果表明,所提出的算法能够提升交通信号灯识别的精度和召回率,识别准确率可以达到90%左右。 相似文献
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乳酸链球菌素(Nisin)和ε-聚赖氨酸是由微生物产生的安全的天然防腐剂,分别由乳酸链球菌和白色链霉菌产生。这两种生物防腐剂的抑菌效果不同,存在互补性。为了获得具有更广谱抑菌作用的优良性状的菌株,探索远缘细胞融合的可行性,以自主分离的ε-聚赖氨酸产生菌白色链霉菌YB12和Nisin产生菌NZ9700作为亲本菌株,通过原生质体融合技术将两个菌株进行门间的细胞融合;通过抗药性筛选、形态学观察、SRAP-PCR分子鉴定,成功获得两株稳定遗传的融合菌株。同时对融合菌株的抑菌活性进行了检测。 相似文献
64.
An increasing amount of commercial measurement instruments implementing a wide range of measurement technologies is rapidly becoming available for dimensional and geometric verification. Multiple solutions are often acquired within the shop-floor with the aim of providing alternatives to cover a wider array of measurement needs, thus overcoming the limitations of individual instruments and technologies.In such scenarios, multisensor data fusion aims at going one step further by seeking original and different ways to analyze and combine multiple measurement datasets taken from the same measurand, in order to produce synergistic effects and ultimately obtain overall better measurement results.In this work an original approach to multisensor data fusion is presented, based on the development of Gaussian process models (the technique also known as kriging), starting from point sets acquired from multiple instruments. The approach is illustrated and validated through the application to a simulated test case and two real-life industrial metrology scenarios involving structured light scanners and coordinate measurement machines.The results show that not only the proposed approach allows for obtaining final measurement results whose metrological quality transcends that of the original single-sensor datasets, but also it allows to better characterize metrological performance and potential sources of measurement error originated from within each individual sensor. 相似文献
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随着科学技术水平的不断提高,在学校教育中应用多媒体CAI的现象越来越普遍,并且受到了广大师生的喜爱。在篮球技术教学中,多媒体CAI课件得到了广泛的应用,并且发挥了非常重要的作用,促进了学生篮球技术水平的提高,实现了预期的教学效果。 相似文献
69.
Xiaolong Cai Chenglin Du Zixuan Sun Ran Ye Haijun Liu Yu Zhang Xiangyang Duan Hai Lu 《半导体学报》2021,42(5):37-48
Gallium nitride (GaN)-based high-electron mobility transistors (HEMTs) are widely used in high power and high frequency application fields,due to the outstanding physical and chemical properties of the GaN material.However,GaN HEMTs suffer from degradations and even failures during practical applications,making physical analyses of post-failure devices extremely significant for reliability improvements and further device optimizations.In this paper,common physical characterization techniques for post failure analyses are introduced,several failure mechanisms and corresponding failure phenomena are reviewed and summarized,and finally device optimization methods are discussed. 相似文献
70.
The next-generation systems are expected to be largely cyber–physical systems (CPSs) that autonomously control physical processes, through sensors and actuators typically in real-time feedback and cooperative control loops distributed among physical and cyber environments. The rapid technological advancements enhance the smartness of these CPSs, pushing their boundaries of performance and efficiency by embedding new information and communication technologies. However, to what extent CPSs should be smarter so that they do not compromise safety and security of safety critical systems? is an open research question. Towards this goal, the purpose of this study is to establish a grounded theory to analyse what makes these systems smart? and eventually, how to find a balance between smartness and safety risks? In this precinct, this article aims to develop a conceptual framework, define the dimensions and derive the characteristics that make CPSs smart. The proposed approach combines an automated informetric and systematic analysis of literature pertinent to the topic of smartness across anthropology, science, engineering and technology. The analysis of a case study building and the discussions presented herein support the connection between the existing understanding of CPSs and smartness offered by the building design approach in urban environment. 相似文献