Closed-loop identification of systems with uncertain time delays using ARX-OBF structure

Closed-loop identification of systems with known time delays can be effectively carried out with simple model structures like Autoregressive with Exogenous Input (ARX) and Autoregressive Moving Average with Exogenous Input (ARMAX). However, when the system contains large uncertain time delay, such structures may lead to inaccurate models with significant bias if the time delay estimate used in the identification is less accurate. On the other hand, conventional orthonormal basis filter (OBF) model structures are very effective in capturing the dynamics of systems with uncertain time delays. However, they are not effective for closed-loop identification. In this paper, an ARX-OBF model structure which is obtained by modifying the ARX structure is shown to be effective in handling closed-loop identification of systems with uncertain time delays. In addition, the paper shows that this advantage of ARX-OBF models over simple ARX model is considerable in multi-step ahead predictions.     

A general procedure for the design of bulk acoustic wave filters

This article presents a procedure for the design of bulk acoustic wave (BAW) filters. The procedure consists of optimizing the modified Butterworth‐Van Dyke model of each resonator, considering appropriate technological parameters. The approach is demonstrated first to design a classical aluminum nitride‐based BAW filter but remains valid for other piezoelectric layers, considering either longitudinal or transverse acoustic wave coupling. The approach is finally applied to the design of a lithium niobate (LiNbO₃) BAW filter for wide‐band filtering applications. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

基于GIS的城市可利用建设用地资源筛选应用研究

首先对城市可利用建设用地资源筛选方法进行了分析.给出了城市可利用建设用地资源筛选模型.基于该模型,利用GIS技术,对北京市某区城市可利用建设用地资源筛选进行了典型研究,给出了结论.     

基于子带脉冲压缩的雷达宽带接收方法

宽带信号的大容量高速数据率,使宽带信号实时处理受到软硬件各方面的限制。本文详细研究了宽带信号的子带脉冲压缩处理方法,给出了过采样子带脉冲压缩系统的基本结构,并对该方法的详细性能进行仿真分析,有效地解决了宽带信号的实时处理问题。将该系统应用于实际工程中,对实测数据的处理结果证明了系统的正确性和有效性。     

喷漆室空调盘管的防护与改造

根据北方天气特殊环境的特点，设计一种适合安装并且方便改造的喷漆室空调盘管加热保温及空气过滤装置，并可随时检查维护，根据外部环境温度可以适当可调整相关的设备开启状态。由原来设备进行改良，用料节约，设备易维护，可以有效地节约热能的浪费，以及提高生产效率，降低生产成本，提高产品质量。     

化学试剂及滤纸对沥青腊含量试验的影响

论述了沥青腊含量试验中,乙醚、乙醇、石油醚、丙酮这4种化学试剂的化学性质、挥发时间、安全使用对试验进程与结果、试验者身体健康及生命的影响。     

Optimized Backflushing Process for Fibrous Media in Engine Oil Filtration and Enhancement by Ultrasound

Filter media that are made of metal fiber fleece have been qualified as a very suitable method to clean engine oils from fine particles in large diesel application. However, regeneration by backflushing of these densely packed depth filtration media is a great challenge. In experimental studies, the principles of successful hydrodynamic backflushing could be identified. Furthermore, the auxiliary effects of medium‐ and high‐power ultrasound on this process were investigated and could be qualified. Ideal process parameters for the general aim of freeing filter media from clogging particle fractions whilst using minimized amounts of flushing medium can be derived. This generates input parameters for an optimized apparatus design in real‐scale application.     

丙纶抗静电针刺过滤材料的工艺与性能

对含不锈钢纤维的抗静电过滤布的生产工艺进行了研究,为抗静电过滤布的开发提供了一种途径。选用丙纶和不锈钢纤维为原料,开发针刺抗静电过滤材料,通过三因素三水平正交试验,得出优化工艺参数。对用优化工艺加工出的产品进行轧光整理,对整理前后产品的抗静电性能、过滤效率等进行了测试分析。     

Semicontinuous Discharge of Non‐Newtonian Filter Cakes in Electrofiltration

A novel mode of operation for electrofiltration is presented. The newly developed operation procedure allows for cake removal without disassembling the chamber. Highly viscous filter cakes are discharged from the filtration chamber by inserting air which permits a rapid restart of the process. The cleaning time could be reduced from about 10 min to a few seconds. The semicontinuous operation is liable to full automation and allows for cake discharge and filtration in a short period of time. In successive cycles was proved that the process efficiency is maintained using the same membrane. A fully continuous system can be accomplished by assembling several units in parallel in a single filtration press.     

Pulse-jet filtration: An effective way to control industrial pollution Part I: Theory,selection and design of pulse-jet filter

Pulse-jet filtration is described as one of the most efficient technologies in controlling industrial pollution across the world. The monograph provides the fundamental concept of design and development of pulse-jet filters under varied siutations. For successful running of a filter unit, a comprehensive knowledge base as regards a selection of design and development of filter media is essential; thus, this is incorporated in the monograph. I also discuss technical and commerically attractive solutions for successful operation of industries integrated with pollution control equipment maintaining clean air requirements.