4月15日,美国国家安全局(NSA)和美国网络安全与基础设施安全局(CISA)、美国联邦调查局(FBI)以及加拿大网络安全中心(CCCS)、澳大利亚信号总局网络安全中心(ACSC)、新西兰国家网络安全中心(NCSC-NZ)和英国国家网络安全中心(NCSC-UK)联合...4月15日,美国国家安全局(NSA)和美国网络安全与基础设施安全局(CISA)、美国联邦调查局(FBI)以及加拿大网络安全中心(CCCS)、澳大利亚信号总局网络安全中心(ACSC)、新西兰国家网络安全中心(NCSC-NZ)和英国国家网络安全中心(NCSC-UK)联合发布《安全部署人工智能系统》(Deploying AI Systems Securely)。展开更多
Based on the idea of cyclic conformal cosmology, we discuss how torsion may allow for a cosmological constant, which links the ideas given by Beckwith and QaZi 2023 to a presentation as far as Torsion as given by de S...Based on the idea of cyclic conformal cosmology, we discuss how torsion may allow for a cosmological constant, which links the ideas given by Beckwith and QaZi 2023 to a presentation as far as Torsion as given by de Sabbata and Sir-varam, Erice 1990. The 1990 article claims that Torsion cancels Cosmological vacuum energy whereas our formulation leads to a left over cosmological constant 10<sup>-121</sup> times vacuum energy. Meantime speculation as to how all this relates to black hole physics and speculation given by Corda which replaces traditional firewalls with a different formulation are included as that presentation by Corda uses the idea of a quantum number n, which ties into our own Cosmological constant presentation.展开更多
文摘4月15日,美国国家安全局(NSA)和美国网络安全与基础设施安全局(CISA)、美国联邦调查局(FBI)以及加拿大网络安全中心(CCCS)、澳大利亚信号总局网络安全中心(ACSC)、新西兰国家网络安全中心(NCSC-NZ)和英国国家网络安全中心(NCSC-UK)联合发布《安全部署人工智能系统》(Deploying AI Systems Securely)。
文摘Based on the idea of cyclic conformal cosmology, we discuss how torsion may allow for a cosmological constant, which links the ideas given by Beckwith and QaZi 2023 to a presentation as far as Torsion as given by de Sabbata and Sir-varam, Erice 1990. The 1990 article claims that Torsion cancels Cosmological vacuum energy whereas our formulation leads to a left over cosmological constant 10<sup>-121</sup> times vacuum energy. Meantime speculation as to how all this relates to black hole physics and speculation given by Corda which replaces traditional firewalls with a different formulation are included as that presentation by Corda uses the idea of a quantum number n, which ties into our own Cosmological constant presentation.
文摘针对展成法加工齿轮切削力呈周期性变化引起刀具与工件的相对位姿偏差,导致工件齿轮加工误差的问题,文章提出一种基于自抗扰控制(active disturbance rejection control,ADRC)的主从式电子齿轮箱(electronic gearbox,EGB)控制方法。首先,分析滚齿加工过程中机床各运动轴之间的联动关系,建立斜齿轮加工运动控制数学模型,确立主从式EGB结构模型;其次,建立EGB中各轴跟踪误差与工件齿轮齿廓偏差、齿距偏差和螺旋线偏差之间的数学关系,采用交叉耦合控制(cross-coupling control,CCC)补偿方式求解出各运动轴的补偿量,对从动轴进行补偿;然后,构建基于传统比例积分微分(proportional integral derivative,PID)控制和扩张状态观测器(extended state observer,ESO)的ADRC-EGB,评估EGB从动轴所受的干扰并进行补偿,提高其同步精度和鲁棒性。最后,在开放式实时半实物仿真平台开展滚齿加工运动模拟实验。结果表明该EGB控制结构相较于传统EGB具有更高的同步控制精度和抗干扰能力。
