Urban intersections without traffic signals are prone to accidents involving motor vehicles and pedestrians.Utilizing computer vision technology to detect pedestrians crossing the street can effectively mitigate the o...Urban intersections without traffic signals are prone to accidents involving motor vehicles and pedestrians.Utilizing computer vision technology to detect pedestrians crossing the street can effectively mitigate the occurrence of such accidents.Faced with the complex issue of pedestrian occlusion at signal-free intersections,this paper proposes a target detection model called Head feature And ENMS fusion Residual connection For CNN(HAERC).Specifically,the model includes a head feature module that detects occluded pedestrians by integrating their head features with the overall target.Additionally,to address the misselection caused by overlapping candidate boxes in two-stage target detection models,an Extended Non-Maximum Suppression classifier(ENMS)with expanded IoU thresholds is proposed.Finally,leveraging the CityPersons dataset and categorizing it into four classes based on occlusion levels(heavy,reasonable,partial,bare),the HAERC model is experimented on these classes and compared with baseline models.Experimental results demonstrate that HAERC achieves superior False Positives Per Image(FPPI)values of 46.64%,9.59%,9.43%,and 6.78%respectively for the four classes,outperforming all baseline models.The study concludes that the HAERC model effectively identifies occluded pedestrians in the complex environment of urban intersections without traffic signals,thereby enhancing safety for long-range driving at such intersections.展开更多
信号转导与转录激活因子3(signal transducer and activator of transcription 3,STAT3)存在于细胞质、细胞核、线粒体及线粒体相关内质网膜中,是参与细胞增殖、分化、迁移和免疫调节等多种生理过程的信号转导蛋白。本文概述了STAT3的...信号转导与转录激活因子3(signal transducer and activator of transcription 3,STAT3)存在于细胞质、细胞核、线粒体及线粒体相关内质网膜中,是参与细胞增殖、分化、迁移和免疫调节等多种生理过程的信号转导蛋白。本文概述了STAT3的结构、类型及进入线粒体的途径;阐述了STAT3对细胞的稳态调节,包括介导内质网Ca^(2+)转运的细胞抗凋亡作用、维持线粒体功能的作用机制和对脂质合成与分解代谢的调控机制,进一步从对造血干细胞的调控作用、骨骼肌的调节、线粒体稳态调节和对脂肪合成与代谢的调控等方面探讨了STAT3调控肉色的机制,以期为改善肉色提供理论参考。展开更多
位于平流层的高空平台向上连接卫星、向下连接低空无人机,能够有效支撑空天地一体化信息网络,提供灵活的应急通信。然而,针对高空平台至无人机的下行链路,传统算法采用固定速率,降低链路的平均传输速率,增加了链路的中断概率。为此,提...位于平流层的高空平台向上连接卫星、向下连接低空无人机,能够有效支撑空天地一体化信息网络,提供灵活的应急通信。然而,针对高空平台至无人机的下行链路,传统算法采用固定速率,降低链路的平均传输速率,增加了链路的中断概率。为此,提出基于速率匹配的自由空间光通信(free space optical,FSO)和射频(radio frequency,RF)链路的动态切换算法(rate adaptation-based free space optical and RF dynamic switching,RADS)。RADS算法优先使用FSO链路,若FSO链路的瞬时信噪比低于阈值,就切入RF链路。同时,根据所接收信号的信噪比,采用满足最低误码率要求的传输模式,进而满足速率要求。仿真结果表明,相比于传统的固定速率算法,提出的RADS算法降低了链路中断概率,提升了速率。展开更多
基金Beijing Natural Science Foundation(9234025)National Social Science Fund Project of China(21FGLB014)Humanity and Social Science Youth Foundation of Ministry of Education of China(21YJC630094).
文摘Urban intersections without traffic signals are prone to accidents involving motor vehicles and pedestrians.Utilizing computer vision technology to detect pedestrians crossing the street can effectively mitigate the occurrence of such accidents.Faced with the complex issue of pedestrian occlusion at signal-free intersections,this paper proposes a target detection model called Head feature And ENMS fusion Residual connection For CNN(HAERC).Specifically,the model includes a head feature module that detects occluded pedestrians by integrating their head features with the overall target.Additionally,to address the misselection caused by overlapping candidate boxes in two-stage target detection models,an Extended Non-Maximum Suppression classifier(ENMS)with expanded IoU thresholds is proposed.Finally,leveraging the CityPersons dataset and categorizing it into four classes based on occlusion levels(heavy,reasonable,partial,bare),the HAERC model is experimented on these classes and compared with baseline models.Experimental results demonstrate that HAERC achieves superior False Positives Per Image(FPPI)values of 46.64%,9.59%,9.43%,and 6.78%respectively for the four classes,outperforming all baseline models.The study concludes that the HAERC model effectively identifies occluded pedestrians in the complex environment of urban intersections without traffic signals,thereby enhancing safety for long-range driving at such intersections.
文摘信号转导与转录激活因子3(signal transducer and activator of transcription 3,STAT3)存在于细胞质、细胞核、线粒体及线粒体相关内质网膜中,是参与细胞增殖、分化、迁移和免疫调节等多种生理过程的信号转导蛋白。本文概述了STAT3的结构、类型及进入线粒体的途径;阐述了STAT3对细胞的稳态调节,包括介导内质网Ca^(2+)转运的细胞抗凋亡作用、维持线粒体功能的作用机制和对脂质合成与分解代谢的调控机制,进一步从对造血干细胞的调控作用、骨骼肌的调节、线粒体稳态调节和对脂肪合成与代谢的调控等方面探讨了STAT3调控肉色的机制,以期为改善肉色提供理论参考。
文摘位于平流层的高空平台向上连接卫星、向下连接低空无人机,能够有效支撑空天地一体化信息网络,提供灵活的应急通信。然而,针对高空平台至无人机的下行链路,传统算法采用固定速率,降低链路的平均传输速率,增加了链路的中断概率。为此,提出基于速率匹配的自由空间光通信(free space optical,FSO)和射频(radio frequency,RF)链路的动态切换算法(rate adaptation-based free space optical and RF dynamic switching,RADS)。RADS算法优先使用FSO链路,若FSO链路的瞬时信噪比低于阈值,就切入RF链路。同时,根据所接收信号的信噪比,采用满足最低误码率要求的传输模式,进而满足速率要求。仿真结果表明,相比于传统的固定速率算法,提出的RADS算法降低了链路中断概率,提升了速率。
