Two guided wave SHM approaches were developed in this project. The first approach is based on a guided wave tomographic technique, in which the region surrounded by a sparse sensor array is monitored. The second one is a phased array approach, in which sensors are attached to a structure in a compact format to form an array. The region subjected to inspection and monitoring is the region outside the array. Both techniques have shown an excellent capability of determining damage size, location, and severity. The importance of guided wave mode and frequency control has been demonstrated for both the tomography and the phased array approach. Guided wave annular arrays have been successfully developed as a means of mode and frequency control. Phased annular array transducers with excellent flexibility on guided wave mode tuning have also been investigated. Guided wave tomography with improved robustness to environmental conditions was demonstrated via the application of specially designed annular arrays. Damage detection using phased array beamforming was also achieved. Unique beamformer transducers were developed and applied to both isotropic and anisotropic multilayer composite structures.

关键词：通信检测；组合结构；结构健康监测；波束形成；相控阵

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关键词：中国；机器人

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2014年1-5月，我国电子信息产业增速出现小幅回落，主要指标增速仍低于去年同期和去年年底水平。当前，我国产业发展面临的国内外环境日趋复杂。国际方面，美国经济发展缓慢，新兴经济体也出现资本外流，经济下行压力较大，对我国出口产生不利影响。国内方面，房地产市场出现明显降温，市场观望情绪日益浓厚，投资增速大幅下滑。但随着本轮我国采取“微刺激”政策作用的逐步显现，将会提升经济内在活力。

关键词：电子信息制造业；微刺激政策；信息产业

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近年来，非洲互联网取得较快发展，互联网用户数和宽带用户数增长非常迅速，网络建设和业务发展需求空间很大，可以说，非洲市场是我国电信业走出去的重要机遇。我国设备制造企业、增值电信企业以及金融机构在产品销售和服务、互联网运营领域以及基础建设项目等方面都有着明显的合作机会。

关键词：非洲互联网业务；电信业发展；机遇

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We present a queueing-theoretic framework to evaluate the performance of large-scale, querybased wireless sensor networks whose nodes detect and advertise significant events that are useful for only a limited time; queries generated by the nodes of the network are also time-limited. The main performance parameter is the steady state proportion of generated queries that fail to be answered on time. Using an infinite transmission range model, we first provide an approximation for this parameter that is insensitive to the size of the network. Subsequently, we approximate the proportion of failed queries when the transmission range is limited and show that this proportion converges to its infinite range counterpart as the sensor transmission range tends to infinity. The analytical approximations are shown to be remarkably accurate when compared with benchmark values obtained using a commercial network simulator.

关键词：通信网络；探测器；排队理论；无线传感器

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In-situ reduction of graphite oxide in polymer powder has been implemented using focused solar electromagnetic radiation. Graphene has proved that it can act as alternative filler in nanocomposites due to its high electronic transport properties and its use in advanced polymer composites for EMI shielding applications. With an applied load, strain measured and corresponding change in resistance of the reduced graphite oxide-polymer composites has been observed. The morphological, structural, electrical, thermal, and electromechanical characteristics of the reduced graphene-PVDF were studied. A gauge factor was obtained demonstrating a promising application as a strain sensor in structural health monitoring.

关键词：传感器；电磁辐射；石墨；聚合物；碳纳米管；复合材料

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An inter-calibration method is developed to provide absolute radiometric calibration of narrow-swath imaging sensors with reference to non-coincident wide-swath sensors. The method predicts at-sensor radiance using non-coincident imagery from the reference sensor and knowledge of spectral reflectance of the test site. The imagery of the reference sensor is restricted to acquisitions that provide similar view and solar illumination geometry to reduce uncertainties due to directional reflectance effects. Spectral reflectance of the test site is found with a simple iterative radiative transfer method using radiance values of a well-understood wide-swath sensor and spectral shape information based on historical ground-based measurements. At-sensor radiance is calculated for the narrow-swath sensor using this spectral reflectance and atmospheric parameters that are also based on historical in situ measurements. Results of the inter-calibration method show agreement on the 2 5 percent level in most spectral regions with the vicarious calibration technique relying on coincident ground-based measurements referred to as the reflectance-based approach. While the variability of the inter-calibration method based on non-coincident image pairs is significantly larger, results are consistent with techniques relying on in situ measurements. The method is also insensitive to spectral differences between the sensors by transferring to surface spectral reflectance prior to prediction of at-sensor radiance. The utility of this inter-calibration method is made clear by its flexibility to utilize image pairings with acquisition dates differing in excess of 30 days allowing frequent absolute calibration comparisons between wide- and narrow-swath sensors.

关键词：传感器；光谱带；灵敏度；成像技术；辐射传输

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In 2007, the Federal Aviation Administration (FAA) Airport Technology Branch conducted a performance assessment of the FODetect(Trade Name), a hybrid radar and electro-optical foreign object debris (FOD) detection system developed by Xsight Systems, Ltd. This assessment included the systems capability to detect objects of various shapes, sizes, and materials at all locations on the runway surface. The systems capability to detect FOD during both nighttime and daytime conditions, in periods of sun, rain, mist, fog, and snow, was also assessed. The FODetect system was initially demonstrated in January 2008. Following the demonstration, a more comprehensive performance assessment of the technology was conducted at the Boston Logan International Airport. The performance assessment was initiated in June 2008 with a test schedule that continued until May 2009. Researchers conducted several test sessions to assess the FODetects capability to detect selected FOD items. The tests focused on hybrid sensor characteristics, specifically the joint capabilities of radar and electro-optical sensors operating together. The FODetect system was able to detect the objects of various shapes, sizes, and materials on runway surfaces and perform satisfactorily in nighttime, daytime, sun, rain, mist, fog, and snow conditions, as required by FAA Advisory Circular 150/5220-24, 'Airport Foreign Object Debris (FOD) Detection Equipment.'

关键词：雷达；探测；光电子技术；航空安全；FOD系统

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This report describes data collected during one of a series of NRL remote sensing and calibration and validation (Cal/Val) campaigns, undertaken to develop models of coastal environments for use in rapidly processing hyperspectral imagery (HSI) and generating shallow water bathymetric charts and trafficability maps. This report describes data collected during the Hawaii- Hyperspectral Airborne Remote Environmental Sensing (HIHARES'09) experiment conducted at Marine Corps Base Hawaii and Marine Corps Training Area-Bellows from January 21 to February 6, 2009. Airborne HSI from the HyMap(TM) sensor was collected over these sites and adjacent areas in conjunction with NRL Cal/Val activities that sampled spectral and geotechnical data for the development and validation of trafficability, shallow water bathymetry, and vegetation maps appropriate to this coralline coast type. Trafficability maps and shallow water bathymetry maps were derived for HIHARES'09 study sites preparatory to an experiment at Shoalwater Bay, Australia, to support the development of imagery- derived trafficability maps for exercise TALISMAN SABER '09.

关键词：远程探测器；高光谱图像；测深，校准

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关键词：传感器；碳化硅；高超声速飞行器；数学模型；微机电系统

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