A Multivariable Two-Degree-Of-Freedom Control Methodology

This paper presents a two-degree-of-freedom design methodology based on a decoupling scheme. The proposed scheme is derived from the Youla parametrization and leads to a two-step design procedure. In the first step, a model-matching approach is proposed in order to set the desired nominal tracking objectives, while in the second step, μ-synthesis techniques are used in order to deal with the robust performance objectives. Special attention is paid to the robust tracking problem. For unstructured uncertainty, the most significant feature of the proposed design is that robust tracking requirements can be achieved, in a satisfactory way, by a simple H_∞ optimization. We carry out the design example on an ill-conditioned plant.     

Modal synthesis of multivariable systems with observers of specified order

The problem of pole assignment in multivariable linear systems with observers of a given order v is considered. By way of a simple proof, a very general result is established which constitutes an extension of all theorems known in the literature on pole assignment via observers. On its basis, an efficient design algorithm is worked out.     

基于内容的差错控制方法研究与实现

视频在传输过程中会因为信道噪声等原因导致失真,采取差错控制方可以保证视频传输的质量.传统的差错控制方法将视频当成普通的比特流,而忽视了视频的内容特征.提出的基于内容的差错控制方法按照内容特征划分视频结构单元并分配相应的差错控制方法.实验结果表明,该差错恢复方法不仅能有效利用信道带宽,而且可保护显著性区域,使重建的视频更加符合用户的视觉需求,实现用小的代价保护重要的视频内容.     

Strategy evaluation for fire spray system on Advanced Passive PWR Severe Accident Management Guideline

The fire spray system (FSS) of the Advanced Passive PWR, as a part of the fire protection system, can provide a non-safety related containment spraying function for severe accident mitigation which is included in the Severe Accident Management Guidelines (SAMG) of the Advanced Passive PWR when dealing with severe accidents. The effectiveness of the FSS is investigated on three effects for severe accident mitigation which are controlling the containment condition, washing out fission product and injecting into the containment through three representative severe accident scenarios analysis with integral accident analysis code since there is no sufficient data support, besides the negative impact is also discussed. Results show that the FSS can be effective for controlling the containment condition, washing out fission product and injecting into the containment, however the effect is limited due to system limitation: the FSS can only cool the containment atmosphere for a short term; the flow rate of FSS cannot fulfill the success criteria given in the PRA report of the Advanced Passive PWR. Meanwhile, the hydrogen concentration and the containment water level should be the long-term monitored because actuating the FSS may cause hydrogen risk in the containment and containment flooding. Despite its limitation and negative impact, the FSS can be effective as an alternative severe accident mitigation measurement for postponing the process of accidents for safety system recovery.     

关于构建厦、漳、泉组合城市初探

本文在分析厦门市、漳州市、泉州市经济发展现状的基础上提出构建厦漳泉组合城市的构想、厦漳泉组合城市的产业空间布局及相应的措施     

西安市老年人居住环境空间设计初探

通过对西安市人口老龄化现状的分析,以老年人生活特点和居住需求为基点,对其养老方式的现状、发展趋势及现存问题进行了研究,并在此过程中发现并探讨了老年人的居住问题,以提高老年人的居住和生活质量。     

Estimation of 2-D DOA using non-circular music method for Uniform Circular and Rectangular Arrays

This paper extends the Non-Circular MUltiple SIgnal Classification (MUSIC) (NC-MUSIC) method for the common array geometries including Uniform Circular Arrays (UCAs) and Uniform Rectangular Arrays (URAs), which enables the algorithm to estimate 2-D Direction Of Arrival (DOA). A comparison between UCAs and URAs of NC-MUSIC is made in this paper. The simulations show that the NC-MUSIC method doubles the maximum estimation number of standard MUSIC. Using non-circular signals, the performance of URAs is improved remarkably while the improvement of UCAs is not so significantly. Moreover, the influence of arrays structures on the NC-MUSIC method is dis-cussed.     

一种改善消力池底板压强分布的新型宽尾墩——XT型宽尾墩

宽尾墩与消力池组成的联合消能形式具有消能率高的特点,但也存在着消力池内的压强分布不均匀,最大冲击压强及动水压强集中度过大的问题。本文结合功果桥水电站整体水工模型试验,提出了一种新型的XT型宽尾墩,对于改善消力池底板上的压强分布,增强底板的稳定具有重要意义。     

The Nine Lives of Buildings

Like cats being gifted with a new life every time they just miss their demise, buildings are constantly propelled towards change and reinvention in order to sustain their existence. Here Jill Stoner , Director of the Azrieli School of Architecture and Urbanism at Carleton University in Ottawa, and Professor of Architecture at the University of California, Berkeley, for 28 years, identifies and reflects upon nine possible future lives for buildings.     

基于内容的差错控制方法研究与实现*

视频在传输过程中会因为信道噪声等原因导致失真,采取差错控制方可以保证视频传输的质量。传统的差错控制方法将视频当成普通的比特流,而忽视了视频的内容特征。提出的基于内容的差错控制方法按照内容特征划分视频结构单元并分配相应的差错控制方法。实验结果表明,该差错恢复方法不仅能有效利用信道带宽,而且可保护显著性区域,使重建的视频更加符合用户的视觉需求,实现用小的代价保护重要的视频内容。