Resistance of a CAST-Like Encryption Algorithm to Linear and Differential Cryptanalysis

Linear cryptanalysis and differential cryptanalysis are two recently introduced, powerful methodologies for attacking private-key block ciphers. In this paper, we examine the application of these two cryptanalysis techniques to a CAST-like encryption algorithm. It is shown that, when randomly generated substitution boxes (s-boxes) are used in a CAST-like encryption algorithm, the resulting cipher is resistant to both the linear attack and the differential attack.     

基于粒子群算法的汽车租赁短期车辆配置问题研究

合理的车辆配置与调度是租车公司运营管理考虑的主要问题之一,也是提高租车公司的租车率和收益的有效途径。针对目前我国租车公司普遍缺乏历史数据、预定提前期短、租期短、门店间距离短等主要运营特点,本文将租车公司运营中频繁而复杂的短期车辆配置问题作为研究对象,提出单日的车辆配置方法,构建随机期望模型,并采用合理的方法分解模型,选择粒子群算法对子模型进行求解,并用数值算例验证了该方法的可行性与效果。该方法能够帮助租车公司管理者做出正确的决策,在提升顾客满意度的同时,提高租车率和租车公司的收益。     

多模跟踪技术在轮式侦察车图像处理器的应用

为解决目标旋转形变、遮挡、光照变化等目标跟踪的难题,对粒子滤波和尺度不变特征变换(SIFT)算法进行了改进,结合两种算法提出了决策主导模式的多模跟踪技术。该技术采用粒子滤波预测目标位置进行粗定位,SIFT特征匹配进行精定位的方法,在解决上述难题上有很好的鲁棒性。将该技术应用于轮式侦察车图像处理器,并进行了各种实验验证,结果证明了提出算法的有效性。     

Quantum private comparison of arbitrary single qubit states based on swap test

By using swap test, a quantum private comparison (QPC) protocol of arbitrary single qubit states with a semi-honest third party is proposed. The semi-honest third party (TP) is required to help two participants perform the comparison. She can record intermediate results and do some calculations in the whole process of the protocol execution, but she cannot conspire with any of participants. In the process of comparison, the TP cannot get two participants' private information except the comparison results. According to the security analysis, the proposed protocol can resist both outsider attacks and participants' attacks. Compared with the existing QPC protocols, the proposed one does not require any entanglement swapping technology, but it can compare two participants' qubits by performing swap test, which is easier to implement with current technology. Meanwhile, the proposed protocol can compare secret integers. It encodes secret integers into the amplitude of quantum state rather than transfer them as binary representations, and the encoded quantum state is compared by performing the swap test. Additionally, the proposed QPC protocol is extended to the QPC of arbitrary single qubit states by using multi-qubit swap test.     

Deterministic Quantum Key Distribution Using Gaussian-Modulated Squeezed States

A continuous variable ping-pong scheme, which is utilized to generate deterministic private key, is proposed. The proposed scheme is implemented physically by using Gaussian-modulated squeezed states. The deterministic characteristic, i.e., no basis reconciliation between two parties, leads a nearly two-time efficiency comparing to the standard quantum key distribution schemes. Especially, the separate control mode does not need in the
proposed scheme so that it is simpler and more available than previous ping-pong schemes. The attacker may be detected easily through the fidelity of the transmitted signal, and may not be successful in the beam splitter attack strategy.     

民营资本进行科技风险投资的多元化战略研究——以杉杉企业为例

从杉杉企业参与科技风险投资的多元化战略实例出发,揭示了民营资本进行科技风险投资的多元化战略的主要意图是顺应外部环境、企业持续发展、提高企业信誉的需要,进而发掘出民营资本投资进军科技风险投资领域的深层意识或动机,其战略思维与运作手法可供相关投资者参考．     

Quantum Private Comparison of Equal Information Based on Highly Entangled Six-Qubit Genuine State

Using the highly entangled six-qubit genuine state we present a quantum private comparison (QPC) protocol, which enables two users to compare the equality of two bits of their secrets in every round comparison with the assistance of a semi-honest third party (TP). The proposed protocol needs neither unitary operations nor quantum entanglement swapping technology, both of which may consume expensive quantum devices. Single particle measurements and Bell-basis measurements, which are easy to implement with current technologies, are employed by two users and TP in the proposed protocol, respectively. The proposed protocol can withstand all kinds of outside attacks and participant attacks. Moreover, none of information about the two users’ private secrets and the comparison result is leaked out to TP.     

时滞车辆跟驰模型及其分岔现象

交通流车辆跟驰理论中, 由于生理因素, 造成司机在处理前方车辆变化信息和采取应对措施之间存在时间滞后. 即使是在自动巡航控制系统中, 设备在感知信息、计算所需操作并最终作动车辆这一过程中时滞也不可避免. 因此交通流跟驰理论的数学模型本质上应包含时滞. 时滞的存在对各种交通模式的出现及其相互演化产生怎样的影响? 这是值得我们关注的问题. 本文首先综述了各类时间和空间连续的时滞车辆跟驰模型.其次探究这类模型中存在的分岔现象的研究进展, 并指出目前研究中存在的不足. 最后提出作者的一些看法,运用时滞动力系统理论来深入挖掘富含参数的交通流时滞跟驰模型中隐藏的各种的非线性动力学现象, 这样既可以更好解释真实交通中的各种堵塞模式的形成及其演化机制, 又可以结合交通流参数平面内动力学行为从同步观点给出交通堵塞一种分类. 为交通管理部门的交通控制策略制定提供一定的参考依据, 减缓由于司机反应时滞等因素造成的交通堵塞的发生.     

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。     

乘员股骨在轴向压力-弯矩下的损伤生物力学机理研究

汽车前碰撞事故中在冲击力作用下乘员股骨经常产生骨折创伤.为研究乘员股骨在不同的轴向压力-弯矩作用下的损伤机理及其耐受限度值,首先建立了一个较为精细的50百分位乘员的坐姿下肢有限元模型,并通过模拟股骨动态三点弯曲及下肢的轴向膝部冲击实验对模型的有效性进行了验证.在此基础上,针对股骨在轴向压力-弯矩载荷下的断裂失效分别进行了曲梁力学模型分析及有限元虚拟实验研究.结果表明:股骨骨折位置依赖于膝部轴向压力及弯矩的载荷大小的变化,在预加载弯矩从0增加到676Nm时,股骨失效部位由股骨颈部转移到股骨干末端区域;失效部位发生在颈部及股骨干时的最大力矩分别为285 296Nm和381443Nm.股骨损伤机理的分析结果阐释了在膝部轴向冲击实验中失效部位位于股骨颈部,而在汽车前碰撞事故中仍有大量的股骨干骨折出现的原因.