NOETHER'S THEOREM FOR NONHOLONOMIC SYSTEMS OF NON-CHETAEV'S TYPE WITH UNILATERAL CONSTRAINTS IN EVENT SPACE

To study the Noether's theorem of nonholonomic systems of non_Chetaev's type with unilateral constraints in event space, firstly, the principle of D'Alembert_Lagrange for the systems with unilateral constraints in event space is presented, secondly, the Noether's theorem and the Noether's inverse theorem for the nonholonomic systems of non_Chetaev's type with unilateral constraints in event space are studied and obtained, which is based upon the invariance of the differential variational principle under the infinitesimal transformations of group, finally, an example is given to illustrate the application of the result.

Influence of Constraint in Parameter Space on Quantum Games

We study the influence of the constraint in the parameter space on quantum games.Decomposing SU(2)operator into product of three rotation operators and controlling one kind of them,we impose a constraint on the parameter space of the players' operator.We find that the constraint can provide a tuner to make the bilateral payoffs equal,so that the mismatch of the players' action at multi-equilibrium could be avoided.We also find that the game exhibits an intriguing structure as a function of the parameter of the controlled operators,which is useful for making game models.

Unified symmetry of the nonholonomic system of non-Chetaev type with unilateral constraints in event space

This paper studies the unified symmetry of a nonholonomic system of non-Chetaev type with unilateral constraints in event space under infinitesimal transformations of group. Firstly, it gives the differential equations of motion of the system. Secondly, it obtains the definition and the criterion of the unified symmetry for the system. Thirdly, a new conserved quantity, besides the Noether conserved quantity and the Hojman conserved quantity, is deduced from the unified symmetry of a nonholonomic system of non-Chetaev type with unilateral constraints. Finally, an example is given to illustrate the application of the results.

Dynamics and adaptive control of a dual-arm space robot with closed-loop constraints and uncertain inertial parameters

A dynamics-based adaptive control approach is proposed for a planar dual-arm space robot in the presence of closed-loop constraints and uncertain inertial parameters of the payload. The controller is capable of controlling the po- sition and attitude of both the satellite base and the payload grasped by the manipulator end effectors. The equations of motion in reduced-order form for the constrained system are derived by incorporating the constraint equations in terms of accelerations into Kane＇s equations of the unconstrained system. Model analysis shows that the resulting equations perfectly meet the requirement of adaptive controller design. Consequently, by using an indirect approach, an adaptive control scheme is proposed to accomplish position/attitude trajectory tracking control with the uncertain parameters be- ing estimated on-line. The actuator redundancy due to the closed-loop constraints is utilized to minimize a weighted norm of the joint torques. Global asymptotic stability is proven by using Lyapunov＇s method, and simulation results are also presented to demonstrate the effectiveness of the proposed approach.

A Novel Generalized Nonholonomy Criteria and Physical Interpretation of Holonomic/Nonholonomic Constraints of a Free-Flying Space Robot with/without Interaction with a Flying Target Satellite

This paper presents a new nonholonomy criteria and reveals the physical interpretation of holonomoic and nonholonomic constraints acting on a free-flying space robot with or without interaction with a free Flying/Floating target object. The analysis in this paper interprets the physical interpretation behind such constraints, and clarifies geometric and kinematic conditions that generate such constraints. Moreover, a new criterion of finding the holonomy/nonholonomy of constraints impose on a free-flying space robot with or without interaction with a floating object is presented as well. The proposed criteria are applicable in case of zero or non-zero initial momentum conditions. Such nonholonomy criteria are proposed by utilizing the concept of orthogonal projection matrices and singular value decomposition (SVD). Using this methodology will also enable us to verify online whether the constraints are violated in case of real-time applications and to take a correction action or switch the controllers. This criterion is still yet valid even the interaction with floating object is lost. Applications of the proposed criteria can be dedicated to in-orbit servicing robotic satellite to capture malfunctioned spacecrafts and satellites, docking space of NASA and Russian shuttles with International Space Station (ISA), building in-orbit stations, space rescue missions and asteroids dust sampling. Finally, simulation results are presented to demonstrate the effectiveness of the proposed criterion.

State Space Model Predictive Control of an Aerothermic Process with Actuators Constraints

This paper investigates State Space Model Predictive Control (SSMPC) of an aerothermic process. It is a pilot scale heating and ventilation system equipped with a heater grid and a centrifugal blower, fully connected through a data acquisition system for real time control. The interaction between the process variables is shown to be challenging for single variable controllers, therefore multi-variable control is worth considering. A multi-variable state space model is obtained from on-line experimental data. The controller design is translated into a Quadratic Programming (QP) problem, in which a cost function subject to actuators linear inequality constraints is minimized. The outcome of the experimental results is that the main control objectives, such as set-point tracking and perturbations rejection under actuators constraints, are well achieved for both controlled variables simultaneously.

土地出让市场化对城市碳排放绩效的影响研究--基于城市面板数据的检验分析

文章基于2011—2022年中国地级市的面板数据,测算地级市土地出让市场化水平与地级市碳排放绩效,采用空间面板模型、工具变量法及调节效应模型等实证方法,检验了土地出让市场化对城市碳排放绩效的影响及其内在机制。研究发现:土地出让市场化与城市碳排放绩效之间呈显著的“U”型非线性关系,且通过系列稳健性检验与内生性处理后,该结论依然成立;作用机制检验表明,资源配置与产业结构升级在土地出让市场化对城市碳排放绩效的作用机制中发挥中介作用;调节效应检验表明,双重目标约束在土地出让市场化与碳排放绩效关系中发挥显著调节作用。研究结论有助于深入理解土地出让市场化对城市碳排放绩效的影响效果和内在机理,为推进土地出让市场化发展、提升城市碳排放绩效和优化目标约束提供有益借鉴。

高斯感知约束空间异常的相关滤波目标跟踪

针对目标在复杂场景运动过程中容易出现跟踪丢失问题,提出一种高斯感知约束空间异常的目标跟踪算法。以高斯均匀分布为分布规律建立目标特征采样点,采用卷积结构提取目标的外观模型以及权重模型;为了约束空间异常,在目标函数中构建空间正则项,同时更新目标权重模型,减小空间过拟合的产生,增强跟踪器的空间异常适应性;应用加权最小二乘法思想,获得权重响应模型中心,确定目标中心,更新跟踪位置,增强跟踪器鲁棒性。使用OTB2015和UAV20L数据集,与其他主流相关滤波算法相比,该算法在目标运动导致低分辨率、遮挡等复杂条件下,跟踪成功率以及跟踪精度较高。

基于足间距信息辅助的行人三维惯性定位算法

针对行人惯性导航系统误差随时间累积致使定位精度严重下降的问题,提出了一种基于足间距信息辅助的行人三维惯性定位算法。该算法在零速修正算法的基础上,利用足部安装的超声波测距模块实时测量行人双足相对距离,构建了基于超声测距的足间距约束模型,通过随机森林算法实现行人运动模式识别,并针对上下楼梯场景,利用台阶高度和足间距信息进行高度解算,最终实现行人三维惯性定位。在实际路线上开展了三维定位实验,数据显示,所提算法平面闭环误差为总路程的0.64%,与零速修正算法相比下降了55.56%,高度误差为0.06 m,与零速修正和气压计联合算法相比下降了64.70%,能够实现导航误差在总路程的0.50%以内的三维定位。实验结果表明,所提算法具有良好的工程应用价值。

基于空间约束联合字典学习的三维冲击波超压场重建

针对有限测点条件下冲击波超压场全时空全区域重建的需求,提出一种基于空间约束联合字典学习的三维冲击波超压场重建方法。建立三维走时层析成像模型,利用字典学习对图像的稀疏表征优势和空间约束对图像边缘纹理保真特性,采用交替最小化思想对目标函数进行优化解算,实现大型病态稀疏矩阵的高精度求解。试验结果表明,该方法与代数重建算法(ART)、联合代数重建算法(SART)和期望极大化算法(EM)相比,重建精度更高,全区域重建误差达到了15.81%,在时空场重建过程中具有较高的应用价值。

基于Innovus混合放置的布局规划方法优化

随着集成电路后端设计中宏单元数量增多,传统布局规划方法效率低且耗时,而自动布局规划的混合放置(MP)技术存在物理规则违例数量多、电压降大和功耗高等问题。针对传统方式和MP方式的不足,提出了一种优化的MP布局规划方法,通过控制宏单元通道空间和标准单元密度大小、固定边界宏单元位置及脚本修复TSMC芯片集成检查(TCIC)违例的方法解决MP技术存在的问题。研究结果表明,优化的MP方式保留了MP技术的性能、功耗和面积(PPA)优势,且相比于传统方式布线长度优化了28%,时序违例优化了65%,功耗优化了609%。该方案可为多宏单元大规模设计的布局规划提供参考。

面向空调管路布置的空间向量搜索算法

针对构型要求复杂且经验类规则难以量化的空调压缩机管路布置问题,文章提出一种基于逃逸法的向量搜索管路布置算法。该算法分为预处理和搜索2个过程。在预处理过程中,使用三维网格记录管路布置空间信息,根据管路直径确定网格大小。对于有无构型要求的2种管路,采用不同形状的单元格来划分网格,保证单元格精度满足要求,减少算法运算量。在搜索过程中,有构型要求管路采用竖直向量圆周搜索,无构型要求管路采用竖直水平向量交替搜索,确保走管路径符合空调管路布置规范要求。通过算例分析验证了该算法的有效性,可为突破复杂约束条件下空调器管路自动布管技术提供算法支撑。

二态量子系统准确布居动力学的一类新型相空间表示及其与三角窗函数的关系

二态系统是最简单的且无经典对应的量子系统,对二态系统的同构表示的认识和研究能启发研究人员对其动力学与统计行为的更深刻理解.本文使用在[J.Chem.Phys.145,204105(2016);J.Chem.Phys.151,024105(2019);J.Phys.Chem.Lett.12,2496(2021)]等文章中发展的约束相空间严格理论、非协变相空间函数、含时权重函数与含时归一化因子来构建一类新型量子相空间表示.这类同构表示可以导出二态量子系统布居动力学的准确结果.约束相空间上的轨迹运动方程同构于含时薛定谔方程.每条相空间轨迹对于布居动力学所对应积分表达式的贡献严格半正定。进一步证明了在[J.Chem.Phys.145,144108(2016)]这篇文章中根据经验提出的三角窗函数方法在本质上可以对应于本文的这类新型相空间表示的一个特殊情况,因此同样是二态量子系统准确布居动力学的同构表示.

银行竞争、空间溢出与产业结构升级

基于我国2011—2020年281个地级市面板数据,研究了银行竞争对城市产业结构升级的影响及其空间溢出效应。研究发现:银行竞争能够显著促进城市产业结构升级。机制分析发现,银行竞争通过促进金融集聚和缓解融资约束优化城市产业结构。异质性分析表明,在小规模城市和东部城市样本中,银行竞争推进产业结构升级的效果明显。空间溢出效应表明,银行竞争不仅能够促进本地城市产业结构升级,还能有效辐射至临近城市,助推其加快产业结构升级进程,这一效应主要存在于中部和西部城市。研究结论不仅丰富了银行竞争的经济效益,也为进一步深化金融供给侧改革,助推实体经济高质量发展提供了有益参考。

西北地区典型河流生态环境复苏路径探索——以清水河为例

清水河是宁夏回族自治区内直接入黄的第一大支流,是宁夏重要水源涵养区、生态屏障和生态廊道。为深入践行习近平生态文明思想,以清水河干流为主线,统筹水资源与水域岸线空间,统筹干流、支流和骨干水库,把水资源作为最大的刚性约束,实施河流生态环境复苏。行动思路主要包括优化水库调度体系、完善流量泄放措施、实施用水总量控制、推进水域空间整治、提升监测预警能力和强化生态流量监管等。目的是加快复苏清水河生态环境,不断提升河流生态系统质量和稳定性,建设区域重要的生态安全屏障,打造具有宁夏特色的河湖复苏样板。

集约束下的变分不等式:像空间分析法

变分不等式是一种数学模型,属于平衡问题的一类,常应用于交通均衡问题、经济均衡问题以及生态产业链问题。像空间分析法(ISA)是研究最优问题与平衡问题非常重要的工具之一。为了丰富ISA在变分不等式问题上的研究,在集约束的假设下,利用ISA研究了在欧氏空间中经典变分不等式问题。首先,验证了问题的线性分离性。然后,通过拉格朗日型函数得到了拉格朗日型鞍点条件。最后,给出了变分不等式的最优性条件。

b-距离空间中有限个等式约束下的耦合不动点问题

本文研究了b-距离空间中有限个等式约束下的耦合不动点问题.利用数学归纳法,获得了b-距离空间中一类有限个等式约束下的非线性压缩耦合不动点结果,将已有的Banach空间中的结果推广到b-距离空间中.特别地,我们结果中的压缩条件与空间系数无关.作为应用,得到了对称等式约束下的不动点定理,公共耦合不动点定理以及b-距离空间中非线性压缩不动点定理.这些结果可以推出许多已有结果,甚至将一些结果中的部分条件完全去掉.

距离空间中有限个等式约束下的Geraghty型耦合不动点问题

在距离空间中建立了一类有限个等式约束下的Geraghty型耦合不动点定理。作为推论,得到了对称等式约束下的不动点定理和公共耦合不动点定理。

基于Kriging遗传算法的高速公路应急车道管控优化

针对如何在不同交通流状况下有效提高高速公路运行效率和降低安全风险的问题,提出基于Kriging代理模型的遗传算法优化应急车道管控策略。结合应急车道开放策略的时空特性设计数学优化模型,通过引入Kriging代理模型,结合遗传算法搭建优化框架,采用仿真软件获取数据训练代理模型,以此求解带有开放时间和开放空间双重约束的总行程时间与总碰撞暴露时间最小化问题。对车道控制时间与空间变量的变化频次进行了约束,并对目标函数中效率与安全指标权重变化对优化结果的影响进行了分析。实验表明:该优化方法使路网总行程时间减小14.9%,碰撞暴露时间减小44.2%,控制效果提升。

一种基于数字空间的空间站任务飞控事件规划方法

针对空间站任务飞控事件规划问题,结合资源约束、飞控事件需求数据维度高、事件间互相影响等特点,提出一种基于数字空间的飞控事件规划方法,将飞控事件规划问题转化为数字模型构建、数值计算及飞控事件时序设计问题。结合空间站应用实例,给出了飞控事件规划流程和规划结果分析,验证了方法的有效性,为空间站任务飞控事件规划问题提供了新思路。