Design and performance analysis of networked control systems with random delay

The design and performance analysis of networked control systems with random network delay in the forward channel is proposed, which are described in a state-space form. A new control scheme is used to overcome the effects of network transmission delay, which is termed networked predictive control (NPC). Furthermore, three different ways to choose control input are discussed and the performances are analyzed, respectively. Both real-time simulations and practical experiments show the effectiveness of the control scheme.     

流动贮备系统可靠性分析及实例计算

给出了流动贮备系统可靠性模型,对其进行了可靠性分析,并给出了计算实例．     

闽江福州段防洪整治试验研究

在定床物理模型试验的基础上进行了动床试验,验证优化防洪规划岸线性在特大洪水作用下的河床演变规律,并提出治理南北调整分流比措施的研究成果。     

高性能聚丙烯纤维对再生混凝土力学性能的影响

通过工作性能、立方体抗压、劈裂抗拉及弹性模量试验,研究了不同骨料取代率下的高性能聚丙烯纤维增强再生骨料混凝土(HPP fibers reinforced recycled aggregate concrete,HFRAC)随高性能聚丙烯(high performance polypropylene,HPP)纤维掺量增加...     

Kinetic modeling of dilute solid-liquid two-phase flows with inelastic collisions

A kinetic model was presented for dilute solid-liquid two-phase flows with inelastic collisions by modeling the inelastic collisions with the revised BGK model （Santos and Astillero, 2005） and particle turbulence interactions with the Fokker-Planck operator. The formulated model kinetic equation was solved with the Chapman-Enskog method and the obtained approximate solution was further adopted to derive the constitutive relationships for the conservation equations of the particle phase. The new constitutive relationships would be suitable for the study on dilute solid-liquid two-phase flows such as sediment-laden flows in open channels or rivers.     

脉冲积分微分方程解的有界性与Lagrange稳定性

通过Lyapunov函数与Razumikhin技巧的直接运用,给出了脉冲积分微分方程解的有界性与Lagrange稳定性的判别准则。     

土壤地下空间耦合下天然气泄漏扩散数值模拟

随着燃气管道数量和规模的增加,由于燃气泄漏至相邻地下空间导致燃气爆炸的事故日益突出。为了研究天然气管道泄漏后气体在土壤和地下空间耦合下的扩散过程及规律,本文采用COMSOL软件中建立燃气管道泄漏在土壤和阀门井中扩散的数学模型,分别研究不同管道压力、土壤孔隙率、泄漏口到阀门井水平距离对燃气泄漏扩散的影响,结果表明：随着管道压力和土壤孔隙率的增加,阀门井内甲烷摩尔分数到达爆炸下限的时间相应减小;不同孔隙率条件下阀门井内甲烷摩尔分数差值逐渐稳定在一个定值;泄漏位置距离地下空间小于12.5 m时,阀门井内甲烷摩尔分数到达爆炸下限的时间小于7天,距离大于12.5 m时阀门井内甲烷摩尔分数到达爆炸下限需要一周以上的时间。     

DENISON经济增长因素分析的模型化与经济增长方式

丹尼森的经济增长因素分析是对经济增长理论的重要贡献, 但他没有提供模型化方法。本文提出了对丹尼森的经济增长因素分析进行定量化模型化的方法, 并利用这种模型化方法讨论了经济增长来源与经济增长方式的问题。     

远程教育管理技术及其实现

分析了远程教育管理涉及的教育模式和管理内容,并给出了基于ＣＥＲＮＥＴ、Ｉｎｔｅｒｎｅｔ网络环境下的初步实施方案,对阐述了如何实现ＷＷＷ服务器对数据库的高效防间和系统的安全等有关技术问题。     

Range anomaly suppression based on neighborhood pixels detection in ladar range images

Research on the range anomaly suppression algorithm in laser radar (ladar) range images is significant in the application and development of ladar. But most of existing algorithms cannot protect the edge and linear target well while suppressing the range anomaly. Aiming at this problem, the differences among the edge, linear target, and range anomaly are analyzed and a novel algorithm based on neighborhood pixels detection is proposed. Firstly, the range differences between current pixel and its neighborhood pixels are calculated. Then, the number of neighborhood pixels is detected by the range difference threshold. Finally, whether the current pixel is a range anomaly is distinguished by the neighborhood pixel number threshold. Experimental results show that the new algorithm not only has a better range anomaly suppression performance and higher efficiency, but also protects the edge and linear target preferably compared with other algorithms.