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1.
基于肌电信号的手部动作识别中,肌电信号测量位置的选择直接关系到动作识别的准确率.本文以使用最少的肌电传感器和获得较高的动作识别率为目标,提出一种基于ANOVA （方差分析）和BP神经网络的肌电信号测量位置优选方法.使用4个肌电传感器采集受试者做出指定动作时的肌电信号,提取肌电信号的时域特征,并按测量位置组合构成15个不同的样本进行BP神经网络的训练和测试.采用单因素ANOVA分析测量位置对动作识别结果影响的显著性,采用Tukey HSD将测量位置进行归类,并从动作识别率最高的子集中选择测量位置最少但识别准确率最高的测量位置组合作为最优的肌电信号测量位置.实验结果表明,测量位置对动作识别的结果具有显著的影响,随着测量位置数的增加,动作识别准确率呈上升趋势,最优的测量位置组合为P1+P3+P4,其动作识别准确率为94.6%. 相似文献
2.
智能肌电假手研究作为康复医疗领域中的重要研究内容,始终是国内外研究的热点.随着机器人技术的进步,假手正往仿人型、灵巧性、直觉控制、智能感知方向发展.智能肌电假手应当具有与人手相近的功能,其不仅能通过运动功能重建辅助残疾人进行日常生活,而且还应通过感知反馈功能重建让残疾人产生人机共融的本体感.本文通过对国内外多年的肌电假手研究成果进行分析比较,从质量、灵巧程度、抓取性能、设计原理等多角度分析了假手的机械结构设计要素;另外,本文还较系统地对基于肌电信号的手势识别研究现状进行概述,介绍了目前基于残肢生物信号识别的多种研究思路,并分析了多种基于不同原理的假手信息感知技术,介绍了利用指尖力触觉传感器实现对假手的自适应控制和用户的感知反馈.最后总结了未来假手的研究发展过程中面临的问题与挑战,提出了肌电假手的未来研究方向. 相似文献
3.
近年来,细粒度图像识别逐渐成为计算机视觉领域的研究热点.由于不同类别图像间的视觉差异小、语义鸿沟问题严重,传统的基于视觉特征的细粒度图像识别性能往往不尽人意.针对这些挑战,目前许多学者都在研究基于用户点击数据的图像识别.本文围绕点击数据在图像识别中数据预处理、特征提取和模型构建3大模块中的应用,总结了已有的基于点击数据的识别算法及最新的研究进展. 相似文献
4.
研究了面向网络攻击的无线传感器网络的分布式目标估计问题.由于测量范围有限,网络中只有部分传感器能测量到目标,而且节点受到随机的攻击从而使得测量值被注入虚假信息.在此背景下,本文提出了基于攻击检测识别策略的改进分布式卡尔曼滤波算法.在该算法中,节点首先基于设计给出的攻击识别阈值来判断其是否受到攻击,生成识别因子;然后以估计误差协方差的迹最小为信息融合原则来设计一致性卡尔曼滤波算法,对处于监测域内的运动目标进行分布式状态估计.同时,分析了算法的收敛性,明确给出了网络估计误差均方有界的随机攻击概率的充分条件.最后用数值仿真验证了算法的有效性和优越性. 相似文献
5.
基于近10年Web of Science数据库中大气科学领域论文数据,利用社会网络分析方法对大气科学研究领域的中国作者科研合作网络进行了探讨.使用UCINET软件分析网络密度、最短距离、小团体、中心性等计量指标,并选择度值较高的节点对其合作网络进行定性分析,识别出重要的领域专家和研究团队.得出的结论有：国内气象学者的合作群体相对分散,倾向于同一地域、相同院校机构的合作,合作规模和合作程度与国际相比仍有一定差距. 相似文献
6.
纸质记录曲线的识别和数字化是图像处理和模式识别领域的一项重要内容, 是对气象档案馆保存的气象纸质曲线资料数字化的有效方法。该文研究并构建了电接风向风速自记纸数字化处理系统, 该系统主要包括4个处理阶段:自记纸图像的输入、图像预处理、自记曲线的分割、曲线的跟踪和识别。其中, 自记纸图像的输入应用TWAIN (Toolkit Without An Interesting Name, 无注名工具包协议) 标准来设计, 对记录曲线的跟踪识别, 该文提出的基于灰度积分投影的分段线性插值算法, 取得了很好的识别效果。 相似文献
7.
随着深度学习技术的不断发展，扫描图像识别技术在提高准确率方面取得了显著进展。本文着重介绍了卷积神经网络和循环神经网络，并比较了它们在图像识别和文字识别任务中的表现。基于卷积神经网络的方法通过构建多层神经网络模型，可以自动学习图像的特征和规律，从而提高识别的准确率，显示出卓越的性能。而循环神经网络在文字识别领域展现了其独特的优势，实验结果表明，循环神经网络能够处理序列数据，并自动学习序列之间的关系。本文的研究结果表明，深度学习算法在扫描图像识别技术中具有广阔的应用前景，卷积神经网络在图像识别任务中表现出色，而循环神经网络在文字识别任务中具有良好的性能。 相似文献
8.
为了提升机器人工程专业学生综合实践能力,本文设计了一款集机、电、控、图像处理于一体的教学机器人实验平台,将机器人机械结构设计、运动学分析、运动控制、图像处理等技术有机融合,不仅提供了机器人关节装配及实物图演示实验,易于学生理论联系实际深入掌握机器人机械结构及工作原理,而且基于开放的控制实验平台,能够完成机器人的运动学分析、驱动控制、轨迹规划、图像处理及基于视觉引导的物体识别与抓取等实验.该实验平台具有很强的综合性和可操作性,激发了学生的学习兴趣,使学生工程实践与创新能力得到有效提升. 相似文献
9.
雷暴云团自动识别和边界相关追踪技术研究 总被引：9，自引：0，他引：9
基于高时空分辨率雷达资料的雷暴云团识别、追踪及预警技术是目前最重要的临近预报预警技术之一.该文描述的雷暴云团边界相关追踪技术是一种新研究的方法,该方法是利用模式识别技术进行云团边界识别、拓扑处理,建立云团生命时序与族谱关系,并在此基础上进行雷暴云团外推的一种短时临近预报方法.该方法有三个主要技术环节:(1)对已预处理的雷达数据进行边界识别;(2)利用四分树匹配分析因子、重叠因子、面积因子、外接矩形因子、轮廓综合因子、局部相似判定因子等六个判断因子,分别识别出每个云团的时间序列,以及每个云团的运动方向、速度、面积、强中心,以及所处的状态(增强或减弱、膨胀或缩小)等信息;(3)对云团的移动方向、速度、面积、强度进行线性外推.初步结果显示该方法可较好地识别和外推预报雷暴云团.在此基础上建立的雷暴自动识别和追踪系统(简称"追踪者",TRACER),可以基于地图系统选取指定云团,获得云团空间位置信息、发展轨迹、演变特征和未来预测,也可对云团预报结果进行定量分析和验证. 相似文献
10.
一种新的梅雨锋上中尺度涡旋识别方法 总被引：1，自引：0，他引：1
中尺度涡旋的发生、发展对梅雨锋暴雨常具有直接作用,客观准确地识别中尺度涡旋有助于提高暴雨预报的准确性。本研究提出一种从格点风场中自动识别中尺度涡旋中心的客观方法。利用美国国家环境预报中心(NCEP)提供的全球模式分析资料,选取2013—2014年梅雨期间两次暴雨个例,考察新方法识别中尺度涡旋的能力,并与现有的两种识别方法(分别基于相对涡度场与基于高度场)进行比较分析。结果表明,由于较小尺度的系统不遵守地转风规则,梅雨锋上许多涡旋的风场环流中心、涡度中心与低压中心位置不重合,影响通过涡度识别或气压识别方法的准确性。新方法从风场出发,可准确识别出大多数涡旋中心,误判率低,定位精度高于无人工辅助下的另外两种方法。接着利用新方法分析了两次暴雨个例中不同中尺度涡旋的垂直结构与时间演变。分析表明,新方法无需人工辅助,无特定层高和时间限制,可在短时间内识别出区域内所有中尺度涡旋的位置、三维结构与时间演变,可用于梅雨期间静止锋上中尺度涡旋的识别和路径的追踪,有助于预报员实时分析与预报暴雨。 相似文献
11.
随着大数据以及社交网络的发展,电子相册与在线服务成为如今人们使用计算机与互联网的基础应用.尤其是近年社交网络的流行,电子相册的数量得到了爆炸增长,而如何增强相册的用户体验变得尤为重要.具有某种主题的相册一般都带有一定的情感信息,因此,本文研究了基于多模态融合的家庭音乐相册自动生成问题,旨在使用户能够在享受音乐的同时配以与音乐情感相同的相册图片.针对音乐与图片中所蕴含的情感,本文在音乐和图像中分别选取能够表达其情感的句子级别的音频特征和图像特征,然后在图像与音乐之间异构和跨模态的特征融合问题上,采用局部保持投影（LPP）方法,将图像特征与音乐特征映射到更具情感分类能力的隐式特征空间中,实现了音乐相册的自动生成.在实验中,客观评测结果表明,采用LPP方法在查准率方面高于纯CCA方法;在主观评测中LPP获得72.06%的满意度,与人工推荐的评价结果（78.09%）比较接近,明显高于随机推荐和CCA方法的满意度. 相似文献
12.
针对如何快速有效地对音乐信息进行查询、检索和组织的问题,提出了一种基于生成对抗网络模型的多标签音乐自动标注系统.通过音乐自动语义标注技术,可以提高音乐检索系统的性能.利用LDA方法对音乐标签进行聚类以获取主题类别,再通过生成对抗网络,找到音乐的音频特征与语义特征之间的映射关系.应用于CAL500数据集的5次交叉验证实验结果表明,该方法的综合性能指标与现有方法相比有较大的提升. 相似文献
13.
This study builds on an earlier analysis of resilience of India and Indian states to climate change. The previous study (Brenkert and Malone, Clim Change 72:57–102, 2005) assessed current resilience; this research uses the Vulnerability–Resilience Indicators Model (VRIM) to project resilience to 2095 and to perform an uncertainty analysis on the deterministic results. Projections utilized two SRES-based scenarios, one with fast-and-high growth, one with delayed growth. A detailed comparison of two states, the Punjab and Orissa, points to the kinds of insights that can be obtained using the VRIM. The scenarios differ most significantly in the timing of the uncertainty in economic prosperity (represented by GDP per capita) as a major factor in explaining the uncertainty in the resilience index. In the fast-and-high growth scenario the states differ most markedly regarding the role of ecosystem sensitivity, land use and water availability. The uncertainty analysis shows, for example, that resilience in the Punjab might be enhanced, especially in the delayed growth scenario, if early attention is paid to the impact of ecosystems sensitivity on environmental well-being of the state. By the same token, later in the century land-use pressures might be avoided if land is managed through intensification rather than extensification of agricultural land. Thus, this methodology illustrates how a policy maker can be informed about where to focus attention on specific issues, by understanding the potential changes at a specific location and time—and, thus, what might yield desired outcomes. Model results can point to further analyses of the potential for resilience-building. 相似文献
14.
Insights into the composition of household vulnerability from multicriteria decision analysis 总被引：5，自引：0，他引：5
Vulnerability is a multidimensional concept associated with high uncertainty in measurement and classification. Developing a vulnerability index from the diverse and often incommensurate data that form the basis of vulnerability assessments is often a core challenge of vulnerability research. Problematically, many vulnerability indices are based on the implicit or explicit assumption that each indicator of vulnerability is of equal importance. In this paper we propose a procedure to engage constructively with the inherent subjectivity and uncertainty of assigning weights to disparate indicators used in vulnerability assessments, using common tools of multicriteria decision analysis (MCDA) and fuzzy logic. To illustrate our proposed methodology, we present a case study of rural livelihood vulnerability in the state of Tamaulipas, México. In our case study, we combine a livelihoods framework with MCDA to weigh household attributes according to their relative importance in driving household vulnerability. This approach requires the explicit articulation of the relationship of each indicator to the umbrella concept (vulnerability) as well as of each indicator to every other indicator. In recognition of the inherent uncertainties involved in assigning any particular unit of analysis to a specific vulnerability class, we use fuzzy logic to create the final categories of household livelihood vulnerability to climatic risk. Our analysis reveals how different structures of livelihood assets and activities contributes to household sensitivity and capacities in a region characterized by variable climatic conditions, stagnant incomes, increasing market stress and declining farm productivity. 相似文献
15.
使用传统协同过滤的方式进行推荐往往会忽视音乐底层特征.通过将音乐的音频特征与歌词信息进行多模态融合,并将融合后的特征信息作为协同过滤推荐的补充,提出了一种基于多模态的音乐推荐系统.主要探讨了音频特征与歌词信息的提取,并在提取歌词信息时利用LDA主题模型进行特征降维.针对多模态融合问题,使用一种特征级联早融合法（EFFC）融合方式,并将多模态融合后的结果与单模态结果进行了比较.对于结果的推荐,以多模态特征信息为依据建立用户兴趣模型,并将该模型通过LSTM神经网络,以过滤与优化协同推荐的用户组.结果表明,基于多模态的音乐推荐系统将推荐结果的误差项平方和（SSE）由传统的2.009降至0.388 6,验证了该方法的有效性. 相似文献
16.
Place attachment, the emotional bonds that people form to significant places, influences adaptation to climate change. Within this context, weather is garnering greater attention for its dynamic, mediating role, yet its political and cultural significance remains under-researched. Here we draw on Serres and McCarren’s (1992) idea of the Natural Contract and Vannini et al.’s (2012) contributions on weathering to integrate contractarianism with a deep account of people’s relationship with weather in place. We analyse attitudes and adaptation to climate change in communities of the geographically-remote and climate-vulnerable Outer Hebrides in Scotland, using video-elicitation to generate data on significant places. Our results show that changing, difficult and unpredictable weather binds people to place and influences how they think about themselves, their place and adaptation in dynamic ways. Through this connection, we demonstrate that people knowingly enter into what we term Weather Contracts and that accepting the volatility of the weather allows people to react positively to changes brought with climate. Finally, we show that the common ideology of a community living with weather generates wider discourses around independence and resisting modernisation that we term a weathered ideology. Thus, climate change is not always a destabilising force. For those who are accustomed to changing weather it can be a dimension of place around which people can organise. Uncertainty and anxiety about the future of the climate is caused more by a lack of control over adaptation processes than by a fear of unknown weather. This has implications for people living at the margins across the globe, where unpredictable weather is a part of local identities, but influence on adaptation policy making is low. 相似文献
17.
The structure of the marine atmospheric boundarylayer and the validity ofMonin–Obukhov similarity theory over the seahave been investigated using longterm measurements. Three levels of turbulencemeasurements (at 10 m, 18 mand 26 m) at Östergarnsholm in themiddle of the Baltic Sea have beenanalysed. The results show that turbulentparameters have a strong dependenceon the actual height due to wave influence.The wind profile and thus thenormalised wind gradient are very sensitiveto wave state. The lower part of theboundary layer can be divided into three heightlayers, a wave influenced layerclose to the surface, a transition layer andan undisturbed ordinary surfacelayer; the depth of the layers is determinedby the wave state. This heightstructure can, however, not be found for thenormalised dissipation, which is onlya function of the stability, except duringpronounced swell where the actualheight also has to be accounted for. Theresults have implications for the heightvariation of the turbulent kinetic energy(TKE) budget. Thus, the imbalancebetween production and dissipation willalso vary with height according to thevariation of wave state. This, in turn,will of course have strong implicationsfor the inertial dissipation method, inwhich a parameterisation of the TKEbudget is used. 相似文献
18.
J. L. Grenfell N. H. Savage R. M. Harrison S. A. Penkett O. Forberich F. J. Comes K. C. Clemitshaw R. A. Burgess L. M. Cárdenas B. Davison G. G. McFadyen 《Journal of Atmospheric Chemistry》1999,33(2):183-214
Calculated and observed hydroxyl (OH) fields are presented. Calculated OH was obtained in three ways using (1) a photochemical box-model (2) a simple OH steady state approach and (3) a variant on (2) – the multiple equation steady state approach which assumes steady state for OH, HO2 and RO2 and hence obtains three simultaneous, non linear, equations. All three methods used data collected in June 1995 during the Weybourne Atmospheric Observatory Summer Experiment (WAOSE'95). Julian Days 169, 178, 179 and 180 displayed especially good data capture and were consequently chosen for study. The two steady state methods are essentially driven purely by observations and derive OH from the ratio of the relevant source and sink terms. The box-model was constrained where possible to observations; remaining unmeasured volatile organic compounds (VOCs) were initialised to an arbitrary low value of 10 ppt. Agreement between theory and experiment was usually around 50% and often better than this value, especially on J169, though discrepancies of up to a factor of 3 were occasionally apparent. Despite the inherent scatter, neither the box-model nor the simple steady state method were found to consistently over-estimate OH (a common feature of many numerical approaches) although this did occur to a certain extent using the multiple equation steady state approach, probably due to breakdowns in the steady state approximation. More data spread was evident in the box-model approach compared with the other methods. An analysis of the major sources and sinks of OH is presented for the three methods of calculation. Calculated and observed peroxy radicals are also presented. Calculated peroxy radicals were generally lower than that observed at night yet higher, sometimes by up to a factor of 7, during the day. Possible explanations for this result are explored. 相似文献
19.
Charles A. Ogunbode Gisela Böhm Stuart B. Capstick Christina Demski Alexa Spence Nicole Tausch 《Climate Policy》2019,19(6):703-715
Climate change is projected to increase the frequency, intensity and unpredictability of extreme weather events across the globe and these events are likely to have significant mental health implications. The mental health literature broadly characterises negative emotional reactions to extreme weather experiences as undesirable impacts on wellbeing. Yet, other research in psychology suggests that negative emotional responses to extreme weather are an important motivation for personal action on climate change. This article addresses the intersection of mental health and functional perspectives on negative emotions, with a specific focus on the potential that reduced negative emotional responses to extreme weather may also translate to diminished motivation to undertake climate change mitigation actions – which we term the ‘resilience paradox’. Using survey data gathered in the aftermath of severe flooding across the UK in winter 2013/2014, we present new evidence indicating that self-appraised coping ability moderates the link between flooding experience and negative emotions and thereby attenuates the indirect link between flooding experience and climate change mitigation intentions. We conclude that support for flood victims should extend beyond addressing emotional, physical and financial stresses to include acknowledgement of the involvement of climate change and communication of the need for action to combat future climate risks.
Key policy insights
Psychological resilience to flooding and other extreme weather events can translate to diminished motivation to mitigate climate change
Negative emotional reactions need to occur at an optimal level to enable people to respond appropriately to climate risks.
Flood victims’ subjective appraisal of their ability to cope does not necessarily encompass consideration of the role played by climate change. Therefore, support for victims of extreme weather should include explicit acknowledgement of the involvement of climate change and the need for action to mitigate future climate risks.
20.
本文利用临界摄动方法,分析了中尺度大气对称扰动系统远离平衡态的物理结构。结果表明,在超临界分叉的条件下,系统远离平衡态,则扰动易强烈发展,系统的结构与Williams和Gray(1973)作合成分析的热带云团的物理结构基本吻合。 相似文献