There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive softw...There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive software to solve this problem,and the experience of engineers is not accurate enough.Therefore,this paper developed a method and system for the startup calculation of group motors in nuclear power plants and proposed an automatic generation method of circuit topology in nuclear power plants.Each component in the topology was given its unique number,and the component class could be constructed according to its type and upper and lower connections.The subordination and topology relationship of switches,buses,and motors could be quickly generated by the program according to the component class,and the simplified direct power flow algorithm was used to calculate the power flow for the startup of group motors according to the above relationship.Then,whether the bus voltage is in the safe range and whether the voltage exceeds the limit during the startup of the group motor could be judged.The practical example was used to verify the effectiveness of the method.Compared with other professional software,the method has high efficiency and low cost.展开更多
针对新型带伪缺口的滑动拼图验证码程序有效阻止了现有方法的攻击,提出改进ResNet18的滑动拼图验证码破解方法。为保证训练模型具有泛化性,通过数据增强方式获取百万级训练样本并进行图像预处理;随后将预处理图像送入改进的ResNet18进...针对新型带伪缺口的滑动拼图验证码程序有效阻止了现有方法的攻击,提出改进ResNet18的滑动拼图验证码破解方法。为保证训练模型具有泛化性,通过数据增强方式获取百万级训练样本并进行图像预处理;随后将预处理图像送入改进的ResNet18进行训练和测试获得网络模型,紧接着使用该模型进行滑块检测和缺口检测计算滑块与缺口之间的距离,并使用随机曲线拟合算法生成滑动轨迹;利用Selenium拖动滑块完成拼图验证。经实验表明改进ResNet18相较于传统的ResNet18参数量减少41%、GFLOPs(Giga Floating-point Operations Per Second)减少59%,在检测精度提高1.8百分点的情况下推理速度快了2.75倍,还能有效破解新型和普通滑动拼图验证码程序,其中mAP(Mean Average Precision)达到98.66%,mAS(Mean Average Speed)为3.68 s,具有较强的普适性且整体性能优于现有方法。展开更多
基金Key Project of National Natural Science Foundation of China(52237008)Beijing Municipal Education Commission Research Program Funding Project(KM202111232022)。
文摘There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive software to solve this problem,and the experience of engineers is not accurate enough.Therefore,this paper developed a method and system for the startup calculation of group motors in nuclear power plants and proposed an automatic generation method of circuit topology in nuclear power plants.Each component in the topology was given its unique number,and the component class could be constructed according to its type and upper and lower connections.The subordination and topology relationship of switches,buses,and motors could be quickly generated by the program according to the component class,and the simplified direct power flow algorithm was used to calculate the power flow for the startup of group motors according to the above relationship.Then,whether the bus voltage is in the safe range and whether the voltage exceeds the limit during the startup of the group motor could be judged.The practical example was used to verify the effectiveness of the method.Compared with other professional software,the method has high efficiency and low cost.
文摘针对新型带伪缺口的滑动拼图验证码程序有效阻止了现有方法的攻击,提出改进ResNet18的滑动拼图验证码破解方法。为保证训练模型具有泛化性,通过数据增强方式获取百万级训练样本并进行图像预处理;随后将预处理图像送入改进的ResNet18进行训练和测试获得网络模型,紧接着使用该模型进行滑块检测和缺口检测计算滑块与缺口之间的距离,并使用随机曲线拟合算法生成滑动轨迹;利用Selenium拖动滑块完成拼图验证。经实验表明改进ResNet18相较于传统的ResNet18参数量减少41%、GFLOPs(Giga Floating-point Operations Per Second)减少59%,在检测精度提高1.8百分点的情况下推理速度快了2.75倍,还能有效破解新型和普通滑动拼图验证码程序,其中mAP(Mean Average Precision)达到98.66%,mAS(Mean Average Speed)为3.68 s,具有较强的普适性且整体性能优于现有方法。
