中世纪佛兰德尔城市经济的兴盛

9-10世纪,佛兰德尔城市相继形成。从11世纪开始,佛兰德尔经济发展迅速。到14世纪前期,佛兰德尔城市经济达到极盛。城市手工业和对外贸易都相当繁盛,呢绒行销欧洲。与此同时,城市规模扩大,人口增加。佛兰德尔由此成为最早出现资本主义萌芽性质的地区之一。     

State feedback control for stochastic Markovian jump delay systems based on LaSalle-type theorem

This paper investigates the problem of stochastic stability and stabilization of stochastic Markovian jump delay systems (SMJDSs) based on LaSalle theorem. The time delays are assumed to be time-varying and numerous stochastic disturbances are considered. Attention is focused on the design of the mode-dependent state feedback controller for SMJDSs based on LaSalle theorem such that the closed-loop SMJDSs are almost surely asymptotically stable. The sufficient conditions for the solvability of the state feedback control problem are obtained in terms of linear matrix inequalities (LMIs). When the LMIs are feasible, the desired state feedback controller is also given. Two numerical examples including the vertical take-off and landing (VTOL) helicopter system are employed to demonstrate the effectiveness and usefulness of the method proposed in this paper     

Output feedback adaptive robust control of hydraulic actuator with friction and model uncertainty compensation

This paper studies output feedback control of hydraulic actuators with modified continuous LuGre model based friction compensation and model uncertainty compensation. An output feedback adaptive robust controller is constructed which combines the adaptive control part and the robust control part seamlessly. The adaptive part is constructed to handle the parametric uncertainties existed in the model. The residuals coming from parameter adaption and the unmodeled dynamics are taken into consideration by the robust part. Since only the position signal is available, the velocity, pressure, and internal friction states are obtained by observation or estimation. The errors coming from observation and estimation are also dealt with the robust part. Furthermore, the convergence of the closed-loop controller–observer scheme is achieved by the Lyapunov method in the presence of parametric uncertainties only. Extensive comparative experiments performed on a hydraulic actuator demonstrate the effectiveness of the proposed controller–observer scheme.     

跨语言文献检索系统研究

[目的/意义]旨在探讨解决原英日文献检索分析中存在的不足,实现以中文为检索语言的中、英、日文献资源的统一检索。[方法/过程]介绍了一种通过机器翻译技术实现以中文为检索语言的中日英文献资源的统一检索系统。[结果/结论]该系统基于MASH-UP技术将检索结果整合进行统一的内容分析,帮助用户跨越语言的障碍,方便地查询和使用外文文献。     

TOE框架下的省级政务大数据发展水平影响因素与发展路径——基于fsQCA实证研究

[研究目的]大数据赋能政府数字化转型已经成为国家治理体系和治理能力现代化的重要抓手。然而,严重的“数字鸿沟”问题依旧是制约我国政务大数据整体发展水平提升重要瓶颈。如何因地制宜发展政务大数据,破解“数字鸿沟”难题亟待学界探究。[研究方法]将TOE框架与中国具体的治理情境相结合,运用模糊集定性比较分析法(fsQCA)对全国31个省(自治区、直辖市)政务大数据发展水平的影响因素与发展路径进行了研究。[研究结论]研究结果表明,省级政务大数据发展水平受到技术、组织和环境三个层面因素的综合影响;其次,共有7种实现省级政务大数据高水平发展的路径;根据主导因素的差异,7种发展路径可归纳为:黄牛型(组织驱动型)、脱兔型(技术驱动型)和雄狮型(技术-组织驱动型)三大发展模式。黄牛型和脱兔型应尽可能向雄狮型的发展模式转变。     

团队多样性氛围、团队凝聚力和团队创造能力的关系研究

通过分析团队多样性氛围和团队创造能力之间的关系,研究发现:团队多样性氛围和团队的凝聚力是正向关系;团队多样性氛围和团队的创造能力之间是正向关系;同时团队凝聚力对团队多样性氛围和团队创造能力之间的关系有部分中介作用。     

基于脱钩指数的2020 年江苏省耕地保有量目标分析

脱钩理论是近年来国际上在测度经济增长与物质消耗之间关系过程中提出的一种理论方法。本研究引入脱钩理论中的脱钩指数及其评价标准,采用历史分析与未来预测相结合的方法,估算了2020年江苏省耕地保有量目标实现的难易程度及其耕地保有量缺口。并且利用试算内插法,测算出了实现耕地保有量目标时的脱钩指数值。研究结果表明：①近30年来,江苏省经济增长与耕地消耗的脱钩指数一直呈现波动下降的趋势,主要是结构效应和政策效应共同作用的结果;②实现2020年耕地保有量目标压力巨大,脱钩指数只有维持在不大于0.0012的水平,才有可能实现耕地保有量目标。因此,在保证经济增长的同时实现耕地保有量规划目标,则必须转变经济增长方式,采取更多积极的政策措施。     

Stability analysis for switched genetic regulatory networks: An average dwell time approach

In this correspondence, the problem of exponential stability for switched genetic regulatory networks (GRNs) with time delays is investigated. The GRNs are composed of N modes and the network switches from one mode to another. By employing the piecewise Lyapunov functional method combined with the average dwell time approach and by using a novel Lyapunov–Krasovskii functional (LKF), sufficient criteria are given to ensure the exponential stability for the switched GRNs with constant and time-varying delays, respectively. These criteria are proved to be much less conservative than the most recent results, since the results reported in this paper not only depend on the delay bounds, but also depend on the partitioning. All the conditions presented here are in the form of matrix inequalities which are easy to be verified via the Matlab toolbox. Two examples are provided in the end of this paper to illustrate the effectiveness of the obtained theoretical results.     

政策引导对中小企业创新绩效的影响机理研究

当前尽管学界围绕政策引导与企业创新间关系取得了丰硕成果,但仍缺乏揭示二者间影响过程的相关研究,且少有研究关注不同类型政策引导方式对企业创新绩效的影响效果。基于现有理论和文献,以国内457家科技型中小企业为研究对象,构建政策引导影响中小企业创新绩效的理论模型并进行实证检验。研究发现：（1）直接性政策引导和间接性政策引导均能显著促进企业创新绩效,且直接性政策引导的促进作用更强;（2）直接性政策引导与企业创新能力之间存在显著倒U型关系,创新能力还在政策引导和企业创新绩效关系间发挥部分中介作用,且在间接性政策引导与创新绩效关系间发挥出的中介作用更强;（3）企业规模正向调节间接性政策引导与企业创新绩效间的关系;（4）研发补贴、企业所得税减免和研发费用加计扣除是最能提升中小企业创新绩效的三种政策引导方式。     

西藏城市给排水工程有关问题的分析与建议

随着经济的快速发展,西藏城市化进程的不断加快,西藏城市市政给排水规划建设问题越来越引起人们的关注。本文分析了我区城市市政给排水规划建设现状,并指出了其中存在的一些主要问题,最后根据我区的实际,给出了几点建议。