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32.
Mohammed A. A. Al-qaness 《地球空间信息科学学报》2019,22(2):128-137
ABSTRACTHuman activity tracking plays a vital role in human–computer interaction. Traditional human activity recognition (HAR) methods adopt special devices, such as cameras and sensors, to track both macro- and micro-activities. Recently, wireless signals have been exploited to track human motion and activities in indoor environments without additional equipment. This study proposes a device-free WiFi-based micro-activity recognition method that leverages the channel state information (CSI) of wireless signals. Different from existed CSI-based micro-activity recognition methods, the proposed method extracts both amplitude and phase information from CSI, thereby providing more information and increasing detection accuracy. The proposed method harnesses an effective signal processing technique to reveal the unique patterns of each activity. We applied a machine learning algorithm to recognize the proposed micro-activities. The proposed method has been evaluated in both line of sight (LOS) and none line of sight (NLOS) scenarios, and the empirical results demonstrate the effectiveness of the proposed method with several users. 相似文献
33.
为探究中国近海大泷六线鱼(Hexagrammosotakii)耳石微化学成分特征及群体分化状况,采集了连云港、青岛、威海、烟台、秦皇岛、大连、丹东7个野生群体和1个威海养殖群体的大泷六线鱼样本。利用LA-ICPMS技术测定耳石中的微量元素,以微量元素与钙的比值进行了分析,结果显示大泷六线鱼耳石中, Na/Ca、Sr/Ca、Fe/Ca、Mg/Ca较高,而Mn/Ca、Ba/Ca、Zn/Ca、Li/Ca较低。耳石1龄前元素比值的组间比较(S-N-K检验)结果显示:Na/Ca、Sr/Ca、Fe/Ca在群体间具显著性差异(P<0.05)。耳石边缘区元素与环境中元素比较发现,Li、Mn元素在耳石中富集程度较大,Sr在耳石的中元素含量远远大于水环境中的浓度,说明耳石中的元素沉积与海水中元素并不是简单的线性关系。判别分析结果显示:耳石1龄前元素指纹的判别分析结果表明,大泷六线鱼群体的判别成功率为63.0%,判别正确范围为30.0%～80.0%,耳石边缘区元素的判别正确率为57.1%,判别正确范围20.0%～80.0%,秦皇岛群体有高的判别成功率80.0%。耳石元素指纹可以用于不同大泷六线鱼群体的... 相似文献
34.
针对行人航位推算(PDR)定位存在误差累积和地磁指纹不唯一导致的误匹配问题,本文改进了基于粒子滤波的PDR/地磁指纹室内定位方法.在PDR定位过程中利用地图信息控制粒子权重更新,得到较为准确的位置信息后,利用动态时间规整(DTW)算法在PDR推算位置基础上进行快速序列匹配,获取最优位置估计.试验结果表明,融合定位方法有... 相似文献
35.
Meretricis concha is a kind of marine traditional Chinese medicine (TCM), and has been commonly used for the treatment of asthma and scald burns. In order to investigate the relationship between the inorganic elemental fingerprint and the geographical origin identification of Meretricis concha, the elemental contents of M. concha from five sampling points in Rushan Bay have been determined by means of inductively coupled plasma optical emission spectrometry (ICP-OES). Based on the contents of 14 inorganic elements (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se, and Zn), the inorganic elemental fingerprint which well reflects the elemental characteristics was constructed. All the data from the five sampling points were discriminated with accuracy through hierarchical cluster analysis (HCA) and principle component analysis (PCA), indicating that a four-factor model which could explain approximately 80% of the detection data was established, and the elements Al, As, Cd, Cu, Ni and Pb could be viewed as the characteristic elements. This investigation suggests that the inorganic elemental fingerprint combined with multivariate statistical analysis is a promising method for verifying the geographical origin of M. concha, and this strategy should be valuable for the authenticity discrimination of some marine TCM. 相似文献
36.
High accuracy seamless positioning is required to support a vast number of applications in varying operational environments. Over the last few years, the global positioning system (GPS) has become the de facto technology for positioning applications. However, its performance is limited in indoor and dense urban environments due to multipath as well as signal attenuation and blockage. A number of techniques integrating GPS with other positioning technologies have been developed to address the limitations of standalone GPS in these difficult environments. While most of the developed techniques cover the outages of GPS in such environments, they do not provide acceptable performance, in terms of positioning accuracy, especially for some mission-critical (e.g. safety) applications. This paper proposes a tightly coupled (i.e. in the measurement domain) GPS/WiFi integration method which, in addition to addressing GPS outages, improves the overall positioning accuracy to the meter-level, thus satisfying the requirements of a number of location based services and intelligent transport systems applications. The performance of the proposed GPS/WiFi integration method is assessed for a number of scenarios in a simulation environment for an identified dense urban area in London, UK. 相似文献
37.
无线局域网络(WLAN)是一种全新的无线信号传输平台,该文在总结目前无缝定位与导航技术的研究现状、分析存在的问题和发展趋势的基础上,提出了联合GPS和无线局域网络的组合定位方法,以实现室内外的无缝定位与导航.同时,在深入研究卫星导航定位和无线传感器网络定位原理与算法基础上,针对定位环境的不同,提出了无缝定位的解决方案、转换机制和切换策略,并以WiFi网与GPS组合定位算法为例,进行了详细分析和深入讨论,所用算法可以实现无GPS、少于4颗可用卫星以及GDOP值不满足定位情况下的定位,与单独WiFi网络定位算法相比,该算法可以提高定位精度. 相似文献
38.
We present a compilation of published data(field,petrography,ages and geochemistry)from 73 ophiolitic complexes of the Central Asian Orogenic Belt.The ophiolitic complexes,ranging in age from Neoproterozoic to Triassic.have been geochemically classified as subduction-related and subductionunrelated categories applying recent,well-established discrimination diagrams.The subductionunrelated category is further subdivided into Mid-Ocean Ridge type(MOR),a common rift-drift stage and Plume type,and the subduction-related category is subdivided into Backarc(BA),Forearc(FA).Backarc to Forearc(BA-FA)and Volcanic Arc(VA)types.The four subduction-related types define highly different geochemical features,with the BA and FA types defining end members showing subduction influence of 10%-100%and 90%-100%subduction influence,respectively,and the two other types(BAFA and VA)define values between the two end members.The subduction-related category comprises79%of the examined ophiolites,of which the BA type ophiolites is by far the dominant group,followed by the BA-FA type,and with FA and VA types as subordinate groups.The Neoproterozoic and Ordovician complexes exhibit the highest,whereas those of Silurian age exhibit the lowest subduction-influence.Of the remaining 21%subduction-unrelated ophiolites,the MOR type dominates.Both the subductionrelated and subduction-unrelated types,in particular the latter,are commonly associated with alkaline basalts taken to represent ocean island magmatism.Harzburgite,dunite,gabbro and basalt are the common lithologies in all ophiolite types,whereas the BA-FA,FA and VA types generally contain intermediate to felsic rocks,and in the FA type boninites occur.The subduction-related ophiolites types generally show low metamorphic grade,whereas greenschist.amphibolite and blueschist grades occur in the subduction-unrelated and BA types.The highly different subduction contribution(from 0 to 100%in the MOR and FA,respectively),attest to variable dips of the subducting slab,as well as variable flux of subduction-related elements into the mantle above subducting slabs,from where the ophiolite magmas got their geochemical fingerprints.As most MOR ophiolites get subducted to the deep mantle,the subduction-related ophiolites have become a dominant ophiolitic type on Earth’s surface through all times supporting the idea about the early start of Plate Tectonics. 相似文献
39.
采用新颖实用的额外磁道接缝技术及一系列反动态、反静态跟踪技术，编制并实现了软磁盘加密程序Ｎｅｗｌｏｃｋ，使得软磁盘加密变得更加可靠、方便． 相似文献
40.