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。     

基于统计能量法的铁路客车室内高频噪声预测与控制

建立了某客车卧铺车厢的整车统计能量分析模型,通过施加轮轨噪声源激励载荷对该车室内噪声水平进行了预测,500 Hz～2500 Hz频率范围内SEA模型的计算结果与实测值的误差在4dB(A)以内.通过包厢壁板对内部声腔的功率输入贡献分析,澄清了地板振动是包厢内低频噪声的主要贡献者,缝隙泄漏则是室内高频噪声的主要贡献者.依据对不同类型地板降噪能力的对比分析以及缝隙面积大小对室内噪声的影响分析,对该车经降噪治理后,室内声压级可降低2dB(A)～3.2dB(A).     

创新驱动模式下战略性新兴产业政府补贴策略分析

针对政府补贴难以激励战略性新兴产业形成创新驱动力的问题,以新能源汽车产业为例,构建了一个旨在促进企业技术研发的政府创新补贴策略分析模型。假设产业呈现明显的创新驱动特征,模型分别针对政府理性决策与有限理性决策的情况,对政府创新补贴及企业创新投入策略进行了博弈均衡分析,并讨论了技术创新环境的改善对最优策略及局中人收益的影响。结果表明,在创新驱动模式下,企业最优创新投入比例对政府补贴水平不敏感,且过高的补贴可能挤出企业创新投入,容易形成企业套利空间。此外,改善技术创新环境对强化企业市场主体地位,弱化政府管制对市场的干预具有积极作用。     

A Quantum Private Query Protocol for Enhancing both User and Database Privacy

In order to protect the privacy of query user and database, some QKD-based quantum private query(QPQ)protocols were proposed. Unfortunately some of them cannot resist internal attack from database perfectly; some others can ensure better user privacy but require a reduction of database privacy. In this paper, a novel two-way QPQ protocol is proposed to ensure the privacy of both sides of communication. In our protocol, user makes initial quantum states and derives the key bit by comparing initial quantum state and outcome state returned from database by ctrl or shift mode instead of announcing two non-orthogonal qubits as others which may leak part secret information. In this way,not only the privacy of database be ensured but also user privacy is strengthened. Furthermore, our protocol can also realize the security of loss-tolerance, cheat-sensitive, and resisting JM attack etc.     

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.     

Performance analysis of electronic code division multiple access based virtual private networks over passive optical networks

A solution for implementing multiple secure virtual private networks over a passive optical network using electronic code division multiple access is proposed and experimentally demonstrated. The multiple virtual private networking capability is experimentally demonstrated with 40 Mb/s data multiplexed with a 640 Mb/s electronic code that is unique to each of the virtual private networks in the passive optical network, and the transmission of the electronically coded data is carried out using Fabry-Perot laser diodes. A theoretical scalability analysis for electronic code division multiple access based virtual private networks over a passive optical network is also carried out to identify the performance limits of the scheme. Several sources of noise such as optical beat interference and multiple access interference that are present in the receiver are considered with different operating system parameters such as transmitted optical power, spectral width of the broadband optical source, and processing gain to study the scalability of the network.     

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.     

Pension expectations as disincentives to job mobility

I address the measurement problem of the extent to which workers in an industry face disincentives to changing employment because of an interest in private pension benefits. I take an individual worker as the unit of analysis and represent job mobility over the work life by a time-varying point process. I treat the various plan types (pension systems) in a unified way through a general reward function (accumulated benefit function). By merging the employment termination process with this function, I derive two other benefit functions to measure the pension expectations of a worker from current and future employments. I then use these functions to construct a loss function that trades off the benefit gains and losses faced by a worker in a pension system at the time of a potential job change. I apply the methodology developed in the paper to the United States pension system, using data from the 1989 Survey of Consumer Finances. © 1997 by John Wiley & Sons, Ltd.     

基于启发式Q学习的汽车涂装车间作业排序优化

针对汽车涂装车间中的作业优化排序问题,提出一种基于启发式Q学习的优化算法。首先,建立包括满足总装车间生产顺序和最小化喷枪颜色切换次数的多目标整数规划模型。将涂装作业优化排序问题抽象为马尔可夫过程,建立基于启发式Q算法的求解方法。通过具体案例,对比分析了启发式Q学习、Q学习、遗传算法三种方案的优劣。结果表明：在大规模问题域中,启发式Q学习算法具有寻优效率更高、效果更好的优势。本研究为机器学习算法在汽车涂装作业优化排序问题的应用提出了新思路。     

计及网络效应的共享电动汽车租赁网络扩张特征分析与布局算法构建

共享租赁网络规划的合理性是共享电动汽车得以顺利发展的基础。为此,本文以共享租赁网络的合理布局作为主题,对共享电动汽车租赁网络的扩展特征进行建模分析,并据此提出相应的布局算法。研究发现:正负网络效应的综合影响使各类网点呈现出不同的利润特征,而对不同类型网点布局的先后顺序,将对整个网络的利润产生影响;基于此,本文提出两步聚类萤火虫算法,该算法不仅能提高前期搜索的效率和精度,同时通过对各候选网点的归类,可便捷地识别各候选网点的布局顺序。最后,通过算例分析进一步论证了所提算法的适用性。