基于物联网标识的智能家居服务体系架构设计

目前,智能家居领域在互联互通方面主要存在两个问题：一个是家庭环境中多个设备之间无法实现较好的互联互通;另一个问题是智能家居系统所采用的标识、操作平台和编程语言没有统一的标准。异构的服务和设备需要彼此协作来共同执行任务。因此,设备和标识的异构性问题会导致智能家居系统的兼容性较差。本文提出了一种基于物联网标识的全新智能家居服务体系架构,明确了智能家居的各参与方及其之间的关系,设计了智能家居服务的具体流程。这种架构可以在对现有的智能家居产品不做额外改变的前提下,实现不同产品之间的互连互通,提高智能家居系统的兼容性和可扩展性。     

ISO质量管理体系在水文领域的创新性应用

从践行"大水文"理念、满足社会需求和自身发展的角度,阐述了水利部长江水利委员会水文局率先自发导入ISO质量管理体系的动因,介绍了运用PDCA过程方法和系统管理方法构建质量管理体系、改进质量管理模式的创新性思路与做法,以及所取得的成效和仍需持续改进的问题,用自身实践证明了ISO 9000质量管理体系标准是一种很好的质量管理方式,值得推广。     

多特征证据理论融合的视觉词典构建

现有的视觉词典构建方法一般是将多个特征构成整个向量并通过聚类形成视觉词典,这种方法在视觉聚类的过程中只考虑了特征的整体相似性而忽略了不同特征对构建视觉词典的影响。提出了一种基于Dempster-Shafer（D-S）证据理论的多特征融合的视觉词典构建方法。该方法应用证据理论融合不同特征的视觉相似性,构造出更加精确的视觉词典。在证据理论的基础上,使用两种特征实现了对视觉词典的再分,使得相似的特征更好地集中在一类中。与传统视觉词典构建方法相比,本文方法获得了更好的结果。应用以上视觉词典构造方法并将之应用于分类实验,在支持向量机与朴素贝叶斯分类器上取得的分类实验结果表明,应用本文方法构建的视觉词典能有效提高视觉词典的精确度,分类效果得到了很大的提高。     

计算机视觉在精密模具破损检测系统的应用

在图像准确检测问题的研究中,由于在高精密仪器中,各种损伤极其细微,传统的利用模具高斯曲线拟合检测技术在进行这种破损检测时,往往会因为破损部位过小,造成特征混淆,特征寻优过程陷入不收敛的境地,从而降低了精密模具破损检测的准确性.为了避免上述缺陷,提出了一种边缘像素定位的精密模具破损检测算法.利用像素灰度差值方法,提取精密模具图像的像素特征,并将其作为精密模具破损检测的数据基础.利用一种边缘像素定位方法,计算精密模具破损区域边缘的空间位置,从而实现精密模具的破损检测.实验结果表明,利用改进算法进行精密模具破损检测,能够提高检测的精度,从而满足精密模具生产过程中质量检测的需求.     

Android3.0内存管理机制分析

Android是当代移动设备上运行的最流行的操作系统之一。Android 3.0基于Linux 2.6内核版本并在各方面都作了很大的改进,针对Android内存管理,剖析了3.0版本使用的新技术,同时提出了改进的途径。     

WCDMA卫星移动通信RAKE接收机性能分析

研究了基于WSSUS模型的UHF频段卫星移动信道模型,利用该模型在四种典型的信道环境下进行相干RAKE接收,在搭建的RAKE接收仿真平台上,比较了三种不同RAKE合并方式下的误码率性能.仿真结果表明,公共导频符号信道估计能有效地克服传统数据符号中时分插入导频符号传输方式在高速运动和快速变化信道中估计不准确的问题,特别在机载信道环境下,接收机性能有明显提高,同时不会产生多余的时隙延迟,信道跟踪实时性强,算法简单.     

Automatic registration of SeaWiFS and AVHRR imagery

An automatic approach for integrating images from multitemporal and multisensor remote sensing is outlined based on coastlines derived from satellite images. One point on a coastline is taken as a candidate point of ground control points (GCPs). A correlation-relaxation (CR) technique is used to search for the corresponding point in the second image. A decision rule is used to guarantee the correctness of GCPs which are used to compute a polynomial equation for registering two images. The relationship between the accuracy of registration and the number of GCPs indicates that a large number of GCPs will lead to more accurate image registration. The correctness of GCPs can also improve the accuracy of geometric registration. The approach can be used particularly well to register images of coastal areas. Examples are given for registration of SeaWiFS and AVHRR imagery.     

Inverting a forest canopy reflectance model to retrieve the overstorey and understorey leaf area index for forest stands

In this article, the Kuusk–Nilson forest reflectance and transmittance (FRT) model was inverted to retrieve the overstorey and understorey leaf area index (OU-LAI) of forest stands in the Longmenhe forest nature reserve in China. Data from detailed sample sites were collected in 30 forest stands representing the typical vegetation community in the study area. An uncertainty and sensitivity matrix (USM) was used to analyse the sensitivity of the FRT model parameters based on these data. The results indicated that overstorey LAI strongly influenced stand reflectance, whereas understorey LAI had a much lower impact. To predict OU-LAI in forest stands, FRT model inversion is carried out by minimizing a merit function that provides a measure of the difference between the reflectance simulated by the FRT model and the reflectance originating from optimal band selection of Hyperion data. Various combinations of Hyperion bands were tested to evaluate the most effective wavelengths for the inversion of OU-LAI. The best estimates from 17 Hyperion bands (5 VIS, 8 NIR, 4 SWIR) by the FRT model inversion showed an R ²?=?0.41 and RMSE/mean?=?0.21 for overstorey LAI and R ²?=?0.49 and RMSE/mean?=?0.91 for understorey LAI. Advantages and disadvantages of FRT inversion for retrieval OU-LAI combined with Hyperion data are discussed.     

Image‐object detectable in multiscale analysis on high‐resolution remotely sensed imagery

Landscapes are complex systems composed of a large number of heterogeneous components as well as explicit homogeneous regions that have similar spectral character on high‐resolution remote sensing imagery. The multiscale analysis method is considered an effective way to study the remotely sensed images of complex landscape systems. However, there remain some difficulties in identifying perfect image‐objects that tally with the actual ground‐object figures from their hierarchical presentation results. Therefore, to overcome the shortcomings in applications of multiresolution segmentation, some concepts and a four‐step approach are introduced for homogeneous image‐object detection. The spectral mean distance and standard deviation of neighbouring object candidates are used to distinguish between two adjacent candidates in one segmentation. The distinguishing value is used in composing the distinctive feature curve (DFC) with object candidate evolution in a multiresolution segmentation procedure. The scale order of pixels is built up by calculating a series of conditional relative extrema of each curve based on the class separability measure. This is helpful in determining the various optimal scales for diverse ground‐objects in image segmentation and the potential meaningful image‐objects fitting the intrinsic scale of the dominant landscape objects. Finally, the feasibility is analysed on the assumption that the homogeneous regions obey a Gaussian distribution. Satisfactory results were obtained in applications to high‐resolution remote sensing imageries of anthropo‐directed areas.     

A method for retrieving soil moisture in Tibet region by utilizing microwave index from TRMM/TMI data

According to simulation analysis of the advanced integral equation model (AIEM), there is a good linear relationship between emissivity and soil moisture under conditions of given roughness. The normalized difference of emissivities at 19.35 GHz and 10.65 GHz with vertical polarization can partly eliminate the influence of roughness and the squared correlation coefficient is about 0.985. This paper uses the normalized brightness temperature for retrieving soil moisture in Tibet from TRMM/TMI data. This method avoids parametrizing the land surface temperature which is a key parameter for the computation of emissivity. We make some sensitivity analysis for the atmosphere which is the main influence factor for our method. The analysis results indicate that our method is very good for clear days but is not very good when there is rainfall. We evaluate our algorithm by using the ground truth data obtained from GAME‐Tibet and the retrieval error of soil moisture is about 0.04m³ m^?3 relative to experimental data. The analysis indicates that the relationship obtained from the theoretical model should be revised through the local ground measurement data because the method is still influenced by roughness and vegetation. After making a regression revision, the retrieval error of soil moisture is under 0.02m³ m^?3. Finally, we retrieve the soil moisture in Tibet from TRMM/TMI data, and the distribution trend of retrieval results is consistent with the real world.