Threshold proxy quantum signature scheme with threshold shared verification

A threshold proxy quantum signature scheme with threshold shared verification is proposed. An original signer could authorize a group as its proxy signers. Then only t or more of n persons in the proxy group can generate the proxy signature on behalf of the original signer and any t − 1 or fewer ones cannot do that. When the proxy signature needs to be verified, any t or more of n persons belonging to the verification group can verify the message and any t − 1 or fewer ones cannot verify the validity of the proxy signature. Supported by the National Basic Research Program of China (973 Program)(Grant No. 2007CB311100), the National High-Technology Research and Development Program of China (Grant Nos. 2006AA01Z419 and 20060101Z4015), the Major Research Plan of the National Natural Science Foundation of China (Grant No. 90604023), the Scientific Research Common Program of Beijing Municipal Commission of Education (Grant No. KM200810005004), the Scientific Research Foundation for the Youth of Beijing University of Technology (Grant No. 97007016200701), the Doctoral Scientific Research Activation Foundation of Beijing University of Technology (Grant No. 52007016200702), and the National Laboratory for Modern Communications Science Foundation of China (Grant No. 9140C1101010601)     

基于摄像头的直立自平衡智能车设计

设计直立行走式循迹智能车的机械及控制系统;系统选用微控制器MK60为控制核心,利用陀螺仪和加速度传感器,采用互补滤波的方法计算车体的角度和角速度,通过比例微分算法控制智能车车轮的加速度来抵消车模运动倾向,实现智能车直立;单片机通过模拟摄像头进行赛道图像捕捉,采用边沿检测算法识别赛道中心线,计算与设定值的偏差,进而控制左右两个电机产生速度差,完成智能车的转向。经测试,智能车能够在保持直立同时,完成赛道识别,且运行平稳快速。     

影响气球车行驶效率及相关因素研究

对以气球喷气为动力的小车运动状态进行研究,从气球内部的压强入手,综合考虑摩擦力,对气球车的效率进行定义和研究,探究了小车效率的影响因素,并结合实验进行了合理的理论修正,确定了最大效率的范围.     

互联网租车市场的演化博弈分析

通过分析互联网租车市场的出现对传统租车市场造成的影响,以探究通过何种策略避免两个租车市场的恶性竞争,构建了基于Bertrand模型的互联网租车方和传统租车方在合作与非合作条件下的静态博弈,结果显示两者在合作模式下会受困于个体理性与集体理性冲突的矛盾中。因此,为了解决这个矛盾,加入政府部门构建多主体合作演化博弈模型,推导出政府和两个租车市场的演化稳定策略,并对模型的演化路径和演化结果进行研究,以期为政府部门对租车市场的管理决策提供参考。     

Meromorphic Functions Sharing Two Values

By using the idea of weighted sharing of values, the problem of uniqueness of meromorphic functions that share two values is studied. The results in this paper improve some theorems given by M. Ozawa and Yi Hongxun et al.     

涉及齐次微分多项式的亚纯函数的唯一性

本文证明了下述定理：设f是复平面内一个非常数的亚纯函数，H(f,f′,…，f^m)表示关于f的次数m≥2，的齐次微分多项式，再设a和b是f的两个判别的有穷小函数，如果f^m=a=(f,f′，…f^m)=a并且f^m=b=H(f,f′，…f^m)=b,那么f^m=H(f,f′,…f^m)，上述定理改进了L.A.Rubel and C.C.Yang[1],顾永兴[2]和方明亮[3]中的有关结果。     

Probabilistic quantum teleportation of shared quantum secret

Very recently, Lee et al. proposed a secure quantum teleportation protocol to transfer shared quantum secret between multiple parties in a network[Phys. Rev. Lett. 124 060501 (2020)]. This quantum network is encoded with a maximally entangled GHZ state. In this paper, we consider a partially entangled GHZ state as the entanglement channel, where it can achieve, probabilistically, unity fidelity transfer of the state. Two kinds of strategies are given. One arises when an auxiliary particle is introduced and a general evolution at any receiver's location is then adopted. The other one involves performing a single generalized Bell-state measurement at the location of any sender. This could allow the receivers to recover the transmitted state with a certain probability, in which only the local Pauli operators are performed, instead of introducing an auxiliary particle. In addition, the successful probability is provided, which is determined by the degree of entanglement of the partially multipartite entangled state. Moreover, the proposed protocol is robust against the bit and phase flip noise.     

自助跟随平衡车的电子控制器设计与实现

随着科技的不断发展,多种智能感应技术被广泛使用,为人们的生活、工作、学习带来便利。平衡车作为新生的代步工具,具有体积小巧、携带方便、操作简单、代步快捷等优点,正被越来越多的年轻人所接受。但是,传统自主跟随平衡车的电子控制器存在多传感器交互性差、传感器数值运算逻辑滞后、控制响应度差等问题,导致用户体验度降低,限制了自助跟随平衡车的研究与发展。针对问题根源,提出了自助跟随平衡车的电子控制器设计与实现方法。采用多维运算逻辑、动态传感电路、瞬态信号回传技术,对传统自主跟随平衡车的电子控制器存在的问题进行改进设计。通过仿真实验测试证明,提出的自助跟随平衡车的电子控制器设计与实现方法,具有多感应器数据交互运算准确、执行响应度高、指令运行稳定等优点。     

Energy dissipation in the deterministic and nondeterministic Nagel-Schreckenberg models

In this paper, we numerically study energy dissipation per unit time per car E_d in the Nagel-Schreckenberg (NS) model. Numerical results show that there is a critical density over which energy dissipation occurs, but below which no energy loss happens in the deterministic NS model. Energy dissipation depends on both the car density and initial configuration in the deterministic case. The energy dissipation rate, E_d, calculated starting from a completely jammed state whose value is minimum, decreases monotonously with the increase of car density above the critical density. In the nondeterministic case, however, there is no critical density and energy dissipation happens in the whole density region, and initial configuration has no effects on energy dissipation. The dissipated energy has two different contributions: one coming from the interactions and another from the braking noise in the stochastic case. The relative contributions of the two dissipation mechanisms are presented. In the free-flow state, E_d is proportional to p(1−p) where p is the stochastic braking probability. In the case of v_max=1,E_d is proportional to the mean density of “go and stop” car per time step ρ_gs, which is equal to n₀(1−n₀) where n₀ is the fraction of stopped car. Theoretical analyses give an excellent agreement with numerical results.     

Evaluating the Dynamic Load on a High-Speed Railroad Car

The internal dynamic load on a high-speed car following a real rail track with curvature and torsion is evaluated. The centrifugal, gyroscopic, tangential, and Coriolis forces and moments are taken into account. The kinematical parameters were obtained experimentally using an inertial system similar to that used to control space-rocket systems. The Euler-Lagrange equations represented by quaternionic matrices are used to determine the unknown dynamic loads in an explicit analytical form, which makes it possible to evaluate the components of dynamic loads due to the forces and moments acting on the car__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 3, pp. 119–126, March 2005.