H ∞ synchronization of two different discrete-time chaotic systems via a unified model

This paper presents some novel synchronization methods for two discrete-time chaotic systems with different time delays, which are transformed into two unified models. First, the H _∞ performance of the synchronization error dynamical system between the drive unified model and the response one is analyzed using the linear matrix inequality (LMI) approach. Second, the novel state feedback controllers are established to guarantee H _∞ performance for the overall system. The parameters of these controllers are determined by solving the eigenvalue problem (EVP). Most discrete-time chaotic systems with or without time delays can be converted into this unified model, and H _∞ synchronization controllers are designed in a unified way. The effectiveness of the proposed design methods are demonstrated by three numerical examples.

     

三平移并联机器人控制算法

论文对一种三平移并联机器人进行了运动学建模,运用矩阵计算方法得到其机构运动学反解,即根据终端执行器的运动规律,求出原动件在单位时间内的位移,进而求得步进电机在单位时间内所发的脉冲数。实验验证该步进电机控制算法的正确性,为并联机器人的运动控制提供了理论方法。     

中高职3+2一体化课程体系研究——以计算机专业为例

提出现实有效的中高职衔接路径和策略,是当今我国职业教育发展中迫切需要解决的问题。针对中高职衔接教育需求,依据"岗位、任务和能力"三个维度,开展"整体设计,分段实施,递进培养"的中高职3+2一体化课程体系及相关课程标准研究。     

Ergonomic Analysis of Head‐Mounted Night Vision Goggle Systems in Simulated Ground Operations

This study compared the mounting time and strain on the head‐neck while using an old model (forehead and cheek supported) and a new model (head harness supported) of head‐mounted night vision goggle systems in the postures of standing, sitting, and lying prone. The results showed that effectively reducing the mounting time was attributed to the ease and less time required for length adjustments of the head harness in the new model. The novel device received higher positive subjective ratings for convenience and comfort while wearing than did the old model. Although the weight of the new model was decreased to 0.794 kg and the length was reduced to 0.155 m, the loads on the head‐neck complex remained high. These findings suggest that a rifle should be fitted with the night vision goggle or handheld model to decrease neck‐shoulder workload if the prone position is the most frequent and important posture for soldiers. © 2011 Wiley Periodicals, Inc.     

淮阴三站泵站贯流式流道混凝土温度和应力仿真分析

根据淮阴三站泵站工程的流道特点、施工过程、现场环境等实际因素,利用三维非稳定温度场和应力场有限元仿真计算程序,对泵站主体混凝土结构施工全过程的温度场和应力场进行动态仿真计算,分析了施工期泵站贯流式流道墩墙混凝土结构裂缝产生的原因,提出相应的防裂措施.     

淮北平原主要农作物涝渍灾害 损失评估研究

针对淮北平原除涝减灾综合治理与规划中缺乏主要农作物受涝损失调查与评估基础资料的实 际问题,于2010年9月初区域降雨成灾之际,对受涝区进行主要农作物受涝经济损失调查。依据实 地调研成果,通过综合统计分析推求了不同耕地类型不同暴雨强度下的受涝损失率,在此基础上实现 了对淮北平原受涝经济损失的合理评估。     

地震待载作用下地下韵筋混凝土结构 报伤破杯模拟研究

综合运用钢筋混凝土和土体两种材料非线性本构模型,对某工程实例进行地震破坏的模拟研 究。分析结果表明,结构内部在强震作用下产生了混凝土开裂、钢筋屈服等损伤和破坏,通过与采用 弹性结构模型的计算结果进行对比,发现采用弹性结构模型虽然可以得到与非线性模型相近的结构位 移,但是会显著低估结构内发生的变形,并且无法准确指示结构内部发生损伤的部位。因此,采用非 线性结构模型分析地下结构的抗震安全性是非常必要的。     

汾河水库众上礴污染防治对策

汾河水库及上游的81.2 km天然输水河道是太原市地表水源地重要组成部分,其水体质 量直接影响着太原市人民群众的身体健康。为了保证汾河水质,针对性地提出保障措施,如:认 真贯彻落实汾河上游水环境管理有关的法律、法规;制定工业污染源防治方案;加强城镇生活污 水与农村集中排水污染控制;制定面源污染防治方案;制定畜禽养殖污染防治方案;加强河道治 理与内源污染防治等。     

黄河巴彦高勒蒸发实验站水面蒸发模型的建立

采用分段风速函数建立了黄河巴彦高勒蒸发实验站的道尔顿水面蒸发模型,计算结果表明:当风速小于3 m/s时,模型计算蒸发量与实测蒸发量相关关系很好,可基本消除水面蒸发经验公式在不同风速段出现不同系统性误差的现象;风速大于3 m/s时,模型计算结果不太理想。