The success of the tuned mass damper (TMD) in reducing wind-induced structural vibrations has been well established. However, from most of the recent numerical studies, it appears that for a structure situated on very...The success of the tuned mass damper (TMD) in reducing wind-induced structural vibrations has been well established. However, from most of the recent numerical studies, it appears that for a structure situated on very soft soil, soil-structure interaction (SSI) could render a damper on the structure totally ineffective. In order to experimentally verify the SSI effect on the seismic performance of TMD, a series of shaking table model tests have been conducted and the results are presented in this paper. It has been shown that the TMD is not as effective in controlling the seismic responses of structures built on soft soil sites due to the SSI effect. Some test results also show that a TMD device might have a negative impact if the SSI effect is neglected and the structure is built on a soft soil site. For structures constructed on a soil foundation, this research verifies that the SSI effect must be carefully understood before a TMD control system is designed to determine if the control is necessary and if the SSI effect must be considered when choosing the optimal parameters of the TMD device.展开更多
A new method for the identification of the chemical Elements isotopes takes advantage of the isotope Neutron Excess (NE) number. The repre-sentation of the natural isotopes in the Z-NE plane reveals a surprising corre...A new method for the identification of the chemical Elements isotopes takes advantage of the isotope Neutron Excess (NE) number. The repre-sentation of the natural isotopes in the Z-NE plane reveals a surprising correspondence between atom’s nuclear and electronic structures. Nuclear directs the atom electronic structure in spite of the alternative set of numbers ruling the two main atom’s compartments. These compartments appear better integrated than actually considered. The Mendeleev periodic table is rooted in the atom’s nuclear structure. Two recent studies arrive to identical conclusions.展开更多
针对乒乓球目标检测方法易受环境、光线、速度等多种因素干扰导致精度和实时性不佳的问题,提出了一种基于YOLOv5s框架的轻量化乒乓球目标检测算法——SYOLO5(Shuffle-YOLOv5s)。首先,采用改进的ShuffleNetV2网络单元组合重构YOLOv5s主...针对乒乓球目标检测方法易受环境、光线、速度等多种因素干扰导致精度和实时性不佳的问题,提出了一种基于YOLOv5s框架的轻量化乒乓球目标检测算法——SYOLO5(Shuffle-YOLOv5s)。首先,采用改进的ShuffleNetV2网络单元组合重构YOLOv5s主干网络,提高特征提取速度;其次,在特征融合的过程中引入高效通道注意力(ECA)机制,有效提升模型的检测性能;接着,采用SIoU Loss(S-Intersection over Union)作为定位损失函数提升网络的收敛速度和定位精度;最后,贴合乒乓球小尺寸的特点,采用双尺度目标检测,进一步提高模型推理速度。实验结果表明,所提算法与YOLOv5s相比,参数量和计算量分别减少了80%和60%,精确率提升了1.9个百分点。展开更多
基金National Natural Science Foundation of China Under Grant No.59778027State Key Laboratory of Coastal Offshore EngineeringDalian University of Technology Under Grant No.9702
文摘The success of the tuned mass damper (TMD) in reducing wind-induced structural vibrations has been well established. However, from most of the recent numerical studies, it appears that for a structure situated on very soft soil, soil-structure interaction (SSI) could render a damper on the structure totally ineffective. In order to experimentally verify the SSI effect on the seismic performance of TMD, a series of shaking table model tests have been conducted and the results are presented in this paper. It has been shown that the TMD is not as effective in controlling the seismic responses of structures built on soft soil sites due to the SSI effect. Some test results also show that a TMD device might have a negative impact if the SSI effect is neglected and the structure is built on a soft soil site. For structures constructed on a soil foundation, this research verifies that the SSI effect must be carefully understood before a TMD control system is designed to determine if the control is necessary and if the SSI effect must be considered when choosing the optimal parameters of the TMD device.
文摘A new method for the identification of the chemical Elements isotopes takes advantage of the isotope Neutron Excess (NE) number. The repre-sentation of the natural isotopes in the Z-NE plane reveals a surprising correspondence between atom’s nuclear and electronic structures. Nuclear directs the atom electronic structure in spite of the alternative set of numbers ruling the two main atom’s compartments. These compartments appear better integrated than actually considered. The Mendeleev periodic table is rooted in the atom’s nuclear structure. Two recent studies arrive to identical conclusions.
文摘针对乒乓球目标检测方法易受环境、光线、速度等多种因素干扰导致精度和实时性不佳的问题,提出了一种基于YOLOv5s框架的轻量化乒乓球目标检测算法——SYOLO5(Shuffle-YOLOv5s)。首先,采用改进的ShuffleNetV2网络单元组合重构YOLOv5s主干网络,提高特征提取速度;其次,在特征融合的过程中引入高效通道注意力(ECA)机制,有效提升模型的检测性能;接着,采用SIoU Loss(S-Intersection over Union)作为定位损失函数提升网络的收敛速度和定位精度;最后,贴合乒乓球小尺寸的特点,采用双尺度目标检测,进一步提高模型推理速度。实验结果表明,所提算法与YOLOv5s相比,参数量和计算量分别减少了80%和60%,精确率提升了1.9个百分点。
