异步DS-CDMA系统中基于矩阵点除算法的DOA估计

针对异步DS-CDMA系统中的多用户环境,本文提出了一种低复杂度的DOA估计算法——矩阵点除算法。该算法通过对感兴趣信息的逐次分离,实现了DOA的逐路径估计。算法具有两方面显著优势:(1)克服了传统的DOA估计算法在路径总数大于天线阵元数时不能工作这一缺陷:(2)避免了计算复杂的特征值分解运算,大大降低了算法复杂度。仿真实验验证了算法的有效性。     

Adhesive element modelling and weighted static shape control of composite plates with piezoelectric actuator patches

A novel finite element model is presented for static and dynamic analysis of composite plates integrated with a laminated piezoelectric layer, a host laminated composite plate and an adhesive layer between them. A new adhesive element is developed which includes both peel and shear effects in the adhesive layer based on first‐order shear deformation plate theory. The thin adhesive layer between the piezoelectric layer and the host plate is modelled by assuming that it carries constant shear and peel strains throughout its thickness. In addition, a weighted static shape control scheme for finding the optimal voltage distribution for static shape control is given. By selecting different weighting matrices, a variety of items such as displacements, slopes, curvatures, strains and even generalized forces, can be included in finding the optimal actuating voltage for static shape control. The present model is validated by comparing with those results available in the literature. The numerical results show that the weighted linear least method can give a satisfactory voltage distribution to best match the desired shape. Copyright © 2004 John Wiley & Sons, Ltd.     

Effects of Spatial Characteristics on Smart Antenna System with Uniform Linear Antenna Array

1IntroductionCurrently,smart antenna technology can greatly en-hance system performance and i mprove the system ca-pacity so that it has been considered as a keytechnologyinthe third generation wireless communicationsystems .The researches on channel model , beamforming algo-rithms and receive algorithms have been widely carriedout and a great many of proposition have beensubmittedtothe 3th Generation Project Partner (3GPP) . Fromthe viewpoint of link-level and system-level research,many asp…     

自适应电子镇流器控制器IR2520原理及应用

IR2520是自适应镇流器控制器与600V半桥驱动器单片IC ,可用来驱动半桥配置中的荧光灯。文中介绍了IR2520的主要特点和基本原理 ,给出了它的典型应用电路。     

Integrated Smart Sensor Calibration

In many applications electronic sensors are used toimprove performance and reliability of measurement systems. Suchsensors should provide a correct transfer from the physical signalto be measured to the electrical output signal. One importantstep to achieve this, is to calibrate each sensor by applyingdifferent reference input signals and adjusting the sensor transferaccordingly. Besides expensive reference equipment the calibrationprocess takes much time and attention per individual sensor,which means a considerable increase in sensor production costs.By including at the sensor or sensor interface chip a programmablecalibration facility the calibration of such smart sensors caneasily be automated and can be executed for a batch of sensorsat a time, thus minimizing the calibration time and costs. Thispaper presents a calibration method and options for integrationin the smart sensor concept, in hardware as well as in software.An advantage of the proposed method is that it does not needa large matrix of calibration data, which needs to be storedin a look-up table or converted into a correction formula, butinstead it uses a step-by-step approach to correct the sensortransfer at each calibration measurement until the error is sufficientlysmall.     

Advancing controlled release packaging through smart blending

Researchers from Rutgers University and Clemson University have collaborated to develop a concept of using smart blending to generate functional packaging films for the controlled release of active compounds such as antimicrobials, antioxidants and flavour compounds to extend the shelf‐life of food. In this paper, literature results are reviewed to justify the significance of controlled release packaging (CRP) and the research gaps for further development are identified. A major research gap is the lack of packaging materials that can provide the release of active compounds at rates suitable for a wide range of food packaging applications. Smart blending is a promising technology for bridging this research gap. To fully realize the potentials of smart blending, a systematic approach for developing CRP using smart blending is also presented. Copyright © 2005 John Wiley & Sons, Ltd.     

Diel Vertical Migration of Round Goby Larvae in the Great Lakes

One hypothesis for the transcontinental and intra-Great Lakes basin transfer of round gobies (Neogobius melanostomus) has been that round gobies were pumped into the ballast water of ships. During June 2005 in Lake Erie, we obtained evidence of a vertical migration of round goby larvae, when we collected 167 round goby larvae in surface ichthyoplankton net tows at night and zero during day. These results complemented similar findings from the Muskegon River estuary of Lake Michigan during 2003 and 2004, documenting diel vertical migration for the first time in larval round gobies. We suggest vertical migration behavior may have allowed larval round gobies to be transported to and within the Great Lakes via ballast water and dispersed in the Great Lakes via advection of 6.5–8.5-mm long larvae at the surface. Based on our results, if ballast water was only taken on near the surface during daylight hours from May through September when larval round gobies were present, it would have mitigated the spread of round gobies throughout the Great Lakes.     

Optoelectronics in satellite designs

Design of artificial satellites for communication, remote sensing and scientific investigations follows, at present, a fixed pattern based on existing and proven technologies and the requirements of payload or experiment within the constraints of weight, volume and power available. The advances in optoelectronic components and systems have opened up a new dimension in designing satellites of the future, incorporating new technologies. This paper deals with general satellite design concepts based on optoelectronic systems wherever applicable.     

Achievement of specificational information usage with true and false feedback in learning a visual relative-mass discrimination task.

Participants' usage of informational variables in learning visual relative-mass discrimination in collisions was tracked by means of PROBIT correlations. Four groups received feedback that was true or accorded with either of three nonspecificational cue variables. A majority in each group adopted the feedback, but several participants defied the false feedback. Unlike in previous research, the fit to data of the relative-mass invariant could not be bettered by post hoc linear combinations of the cues. Discriminability was lower in the use of the invariant. Analytic complexity was rejected as an explanation for discriminability differences. A "smart mechanism" for pickup of the relative-mass invariant was developed as an extension of G. Johansson's (1950/1994) vector model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

由IR2155驱动的高功率因数电子镇流器

本文介绍了一种由ＩＲ２１５５驱动的电子镇流器功能特点和工作原理。