美国妇女选举权档案开发利用的特色分析及启示     

黄霄羽  位焕锦  黄敏 《北京档案》2020,(5):40-43

美国国家档案馆为纪念宪法《第十九条修正案》100周年,发起一项为期18个月的全国性倡议,带动各州庆祝妇女选举权。本文分析指出美国妇女选举权档案开发利用的内容特色——主题集中、关注个体和突出人物;方式特色——多媒介、数字化和关联式开发并行,最后总结出对我国的启示——档案开发利用宜主题集中、方式多样、把握时机的持续性。  相似文献   

美国大学图书馆馆藏资源组织进展     

蔡颖  蔡迎春 《图书馆论坛》2020,(6):166-173

文章对美国大学图书馆在信息资源组织与利用方面的创新与实践进行梳理总结,以期为国内图书馆的资源建设提供借鉴。选取美国顶尖的11所大学图书馆作为考察对象,重点介绍它们在馆藏特色文献数据化、资源多样化收集与元数据整合、数字资源全生命周期管理方面的特色和进展。图书馆在资源服务方面所扮演的角色在不断演变,美国大学图书馆正借助先进的信息生产、存储和传递技术,向着实现信息资源共建、共知和共享的目标迈进。国内图书馆需要关注新兴技术,加强特藏资源开发,促进纸质与数字资源融合,优化数字资源业务流程。  相似文献   

应用智能手机运动App自我监控日常体力活动的实验研究     

胡永芳  翁锡全  包希哲  曾玲玲 《广州体育学院学报》2020,(5):113-118

目的：探讨应用智能手机运动软件监控体力活动对日常体力活动的影响及其内在机理。方法：选取广州市年龄35~45岁之间的白领38名作为研究对象，实验前、后受试者填写《国际体力活动问卷长卷》问卷，实验中受试者采用动动健康软件管理目标体力活动量，并将每日活动量反馈给监督者，监督者根据受试者上一周的体力活动量，对每名受试者设定下周的目标体力活动量，要求每周活动量较上周增加20%，实验共为期12周。结果：与实验前比较，试验后后第1周、第4周、第8周和12周的步数、能量消耗和活跃时间均非常显著性的增加（P<0.01）；试验后各时间段步数均有所增加，其中，实验前工作日和休息日在17:30-20:00时间段步数最多，试验后工作日步数最多出现在20:00-22:00和17:30-20:002个时间段，休息日出现在8:30-12:00和20:00-22:002个时间段。结论：应用智能手机运动软件进行自我监控可以提高白领日常体力活动量，特别是交通和闲暇时间体力活动。目标设定、自我监控和表现反馈可能是体力活动干预中较为有效的行为改变技术（BCTs）。  相似文献   

Optimal synchronization controller design for complex dynamical networks with unknown system dynamics     

Ya-Wei Cao  Guang-Hong Yang  Xiao-Jian Li 《Journal of The Franklin Institute》2019,356(12):6071-6086

In this paper, the optimal synchronization controller design problem for complex dynamical networks with unknown system internal dynamics is studied. A necessary and sufficient condition on the existence of the optimal control minimizing a quadratic performance index is given. The optimal control law consists of a feedback control and a compensated feedforward control, and the feedback control gain can be obtained by solving the well-known Algebraic Riccati Equation (ARE). Especially, in the presence of unknown system dynamics, a novel adaptive iterative algorithm using the information of system states and inputs is proposed to solve the ARE to get the optimal feedback control gain. Finally, a simulation example shows the effectiveness of the theoretical results.  相似文献   

Intermittent control strategy for synchronization of fractional-order neural networks via piecewise Lyapunov function method     

Ying Yang  Yong He  Min Wu 《Journal of The Franklin Institute》2019,356(8):4648-4676

In this paper, the synchronization problem of fractional-order neural networks (FNNs) with chaotic dynamics is investigated via the intermittent control strategy. Two types of intermittent control methods, the aperiodic one and the periodic one, are applied to achieve the synchronization of the considered systems. Based on the dynamic characteristics of the intermittent control systems, the piecewise Lyapunov function method is employed to derive the synchronization criteria with less conservatism. The results under the aperiodically intermittent control show more generality than the ones via the periodically intermittent control. For each of the aperiodic and periodic cases, a simple controller design process is presented to show how to design the corresponding intermittent controller. Finally, two numerical examples are provided to demonstrate the effectiveness of the obtained theoretical results.  相似文献   

Super-twisting observer-based sliding mode control with fuzzy variable gains and its applications to fully-actuated hexarotors     

Ngo Phong Nguyen  Wonhee Kim  Jun Moon 《Journal of The Franklin Institute》2019,356(8):4270-4303

In this paper, we consider the super-twisting observer-based sliding mode control algorithm with fuzzy variable gains (STOSMC) for the fully-actuated hexarotor. Our hexarotor has full actuation due to six titled propellers that allows to control position and orientation (attitude) simultaneously, and resolves the singularity problem of the rotational matrix by using the quaternion modeling framework. We show that the proposed STOSMC for the hexarotor guarantees finite-time convergence of the estimation error and asymptotic stability of the hexarotor. In simulations, we demonstrate the nonsingularity and fully-actuated control performance of the hexarotor by considering extreme position and attitude control scenarios. Moreover, the simulation results show that the hexarotor achieves the fast and precise tracking performance to the desired position and the desired attitude and the chattering phenomenon is reduced compared with the fixed-gains observer-based super-twisting sliding mode control due to the fuzzy mechanism.  相似文献   

多媒体教学背景下高校公体教学改革探究     

刘露 《体育科技文献通报》2020,(6):90-91

多媒体技术对于教学上的应用,为公共体育教学带来了新的改革。在教学过程中,如何更好的利用多媒体技术教学的优势与公共体育教学相结合,提升高校公体课的成绩,是本文研究的重点。文章通过对于两个班级进行试验研究,以期对多媒体技术在高校公共体育教学上的应用,提供一定的理论参考依据。  相似文献   

Moment matching model reduction for negative imaginary systems     

Lanlin Yu  Junlin Xiong 《Journal of The Franklin Institute》2019,356(4):2274-2293

In this paper, moment matching model reduction problem for negative imaginary systems is considered. For a given negative imaginary system with poles at the origin, our goal is to find a reduced-order negative imaginary system such that a prescribed number of the moments and the poles at the origin are preserved. Firstly, the original negative imaginary system is split into an asymptotically stable subsystem, a lossless negative imaginary subsystem and an average subsystem. Then, moment matching model reduction is implemented on the asymptotically stable subsystem and the lossless negative imaginary subsystem. The resulting reduced-order system preserves the negative imaginary structure and the poles at the origin. Also, the proposed model reduction method is extended to the positive real systems. Numerical examples demonstrate the effectiveness of the proposed model reduction method.  相似文献   

Linear output-feedback-based semi-global stabilization for switched nonlinear time-delay systems     

Zhenhua Li  Lijun Long  Jun Zhao 《Journal of The Franklin Institute》2019,356(13):7224-7245

This paper focuses on the problem of semi-global output-feedback stabilization for a class of switched nonlinear time-delay systems in strict-feedback form. A switched state observer is first constructed, then switched linear output-feedback controllers for individual subsystems are designed. By skillfully constructing multiple Lyapunov–Krasovskii functionals and successfully solving several troublesome obstacles, such as time-varying delay and switching signals and nonlinearity in the design procedure, the switched linear output-feedback controllers designed can render the resulting closed-loop switched system semi-globally stabilizable under a class of switching signals with average dwell time. Furthermore, under some milder conditions on nonlinearities, the semi-global output-feedback stabilization problem for switched nonlinear time-delay systems is also studied. Simulation studies on two examples, which include a continuous stirred tank reactor, are carried out to demonstrate the effectiveness of the proposed approach.  相似文献   

Multi-lagged-input iterative dynamic linearization based data-driven adaptive iterative learning control     

Na Lin  Ronghu Chi  Biao Huang  Zhongsheng Hou 《Journal of The Franklin Institute》2019,356(1):457-473

This article presents a multi-lagged-input based data-driven adaptive iterative learning control (M-DDAILC) method for nonlinear multiple-input-multiple-output (MIMO) systems by virtue of multi-lagged-input iterative dynamic linearization (IDL). The original nonlinear and non-affine MIMO system is equivalently transformed into a linear input-output incremental counterpart without loss of dynamics. The proposed learning law utilizes the desired trajectory to cancel the influence from iteration-by-iteration variations, as well as additional multi-lagged inputs to improve control performance. The developed iterative estimation law is more effective and also makes estimation of the unknown parameters easier because the dynamics for each parameter to represent are decreased by dividing the system into multiple components in the multi-lagged-input IDL formulation. Moreover, the proposed M-DDAILC does not need an explicit and accurate model. It is proved to be iteratively convergent with rigorous analysis. Both a numerical example and a practical application to a permanent magnet linear motor are provided to verify the validity and applicability of the proposed method.  相似文献