Performances of Unknown Input Observers for Chaotic LPV Maps in a Stochastic Context

Jointly modeling chaotic maps as Linear Parameter Varying (LPV) systems and using Unknown Input Observers (UIOs) for retrieving the information in a secure communication scheme has previously been motivated in a deterministic context [Millerioux, G. and Daafouz, J. International Journal of Bifurcation and Chaos 14(4), 2004]. In this paper, some new theoretical results from a control theory point of view, concerning the design in a stochastic and so more realistic context of UIOs for chaotic LPV systems is provided. The design of such observers is expressed in terms of the resolution of a finite set of Matrix Inequalities constraints and guarantees some prescribed performances on the state reconstruction error.     

体外反搏对血管壁剪切应力影响的数值模拟

采用刚性直管流动的数值计算方法 ,对实施体外反搏前后的小猪颈动脉血管流动状况及管壁剪切应力进行了数值模拟。计算结果表明 ,体外反搏可以明显有效地改变血管壁剪切应力。     

Beam Profile Improvement of a LD Array by an External Cavity with Photorefractive Phase Conjugate Mirror

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｓｅｍｉｃｏｎｄｕｃｔｏｒｌａｓｅｒ ｄｉｏｄｅａｒｒａｙｓａｒｅｖｅｒｙａｔｔｒａｃｔｉｖｅｆｏｒｔｈｅｉｒｃｏｍｐａｃｔｎｅｓｓ,ｓｉｍｐｌｅｏｐｅｒａｔｉｏｎ,ｌｏｎｇｌｉｆｅｔｉｍｅ,ａｎｄｈｉｇｈｅｌｅｃｔｒｉｃａｌｔｏｏｐｔｉｃａｌｃｏｎｖｅｒｓｉｏｎｅｆｆｉｃｉｅｎｃｙ.Ｈｏｗｅｖｅｒｔｈｅｓｅｈｉｇｈｐｏｗｅｒｓｏｕｒｃｅｓｈａｖｅａｎｏｎ ｄｉｆｆｒａｃｔｉｏｎ ｌｉｍｉｔｅｄｒａｄｉａｔｉｏｎｐａｔｔｅｒｎｗｉｔｈｖｅｒｙｌｏｗｃｏｈｅｒｅｎｃｅｌｅｎ…     

Measurement of natural radioactivity in Jordanian sand

Sand samples were collected from Adasiah (near Amman), Jerash and Ghor As-Safi (near Karak). ²²⁶Ra, ²³²Th and ⁴⁰K activities, present in these samples, were measured using a gamma ray spectroscopy technique. The average values of the radium equivalent activities were calculated and were found to be 41.06 Bq kg⁻¹, 54.7 Bq kg⁻¹ and 85.53 Bq kg⁻¹ in samples collected from Adasiah, Jerash and Ghor As-Safi, respectively. These values are within the limit (i.e. less than 370 Bq kg⁻¹) recommended for the safe use of construction materials for dwellingsby OECD.     

An Electrostatics Approach to the Determination of Extremal Measures

One of the most important aspects of the minimal energy (or induced equilibrium) problem in the presence of an external field – sometimes referred to as the Gauss variation problem – is the determination of the support of its solution (the so-called extremal measure associated with the field). A simple electrostatic interpretation is presented here, which is apparently new and anyway suggests a novel, rather systematic approach to the solution. By way of illustration, the classical results for Jacobi, Laguerre and Freud weights are explicitly recovered by this alternative method.     

岩土边坡稳定性分析的模糊综合评判实用方法

依据模糊数学的基本原则和方法,根据影响边坡稳定性主要的内在和外在因子,建立模糊综合评判方案,得到边坡稳定性等级分类指数,据此判断出边坡的稳定性情况.工程实例分析结果表明,将该方法应用于实际工程中,具有较大的可靠性,能节约大量的时间,显示出一定的优越性.表3,参11.     

20 W腔外倍频全固态Nd∶YAG绿光激光器

研制了一台高光束质量的全固态Nd∶YAG激光器 ,采用KTP腔外倍频 ,获得了大于 2 0W准连续绿光输出 ,峰功率可达 1.15× 10 5W ,光束质量因子M2 值约为 4。     

化学反应交联的随机热力学效应

根据受噪声作用的有限化学反应系统的随机热力学理论，以存在膜平衡交联的简单反应模型为例，建立了交联体系的有效主方程及有效随机熵平衡方程。进而阐了这类体系中有效熵产生的统计内涵，初步揭示出内涨落和来自化学反应交联的外噪声的随机热化学效应。     

带传动装置中的压轴力及轴承寿命的动态分析及计算

用解析法与矢量图法分析了带传动在动态工作条件下的压轴力及轴承寿命的定量变化，提出了轴承在不同条件下的载荷与寿命计算的正确方法。     

旋转机械振动分析时进行外部采样的一种实现方法

文章给出了在微机上实现外部采样的一种方法，阐述了外部采样硬件电路的工作原理以及外部等转角采样和内部等时间间隔采样参数的关系。最后用外部采样对一个变速过程进行了分析。