共查询到19条相似文献,搜索用时 78 毫秒
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次声传感器采集到的泥石流次声信号中包含有大量的无关干扰信号,严重影响信号的分析与评估。针对含噪泥石流信号中无法准确确定噪声频段的特点,以及传统经验模态分解(Empirical Mode Decomposition, EMD)联合小波阈值去噪方法无法智能分辨噪声所在频段的缺点,提出了信号经EMD分解后,基于相关性选择噪声频段的方法。首先利用EMD分解获取信号的固有模态函数(Intrinsic Mode Function, IMF)分量,然后计算各个IMF分量与原始信号的相关性,根据相关性大小确定IMF噪声频段,然后采用小波阈值去噪方法对噪声频段进行处理,最后对处理后的信号进行重构得到去噪泥石流信号。通过模拟实验分析,证明该方法具有智能选择噪声频段的能力,是一种更适于泥石流信号的去噪方法。 相似文献
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近些年来,基于广义互相关时延估计、单阵定向多阵定位的次声定位技术得到了广泛研究,针对时间差的获取提出了大量改进方法,这些定位方法主要是针对远程次声源的定位。然而,对于持续时间长达3~4 min且处于运动状态的次声事件的定位研究较少。提出了一种基于短时能量突变的方法进行时延估计,并结合实际站台的分布情况采用三站定位方法对火箭发射事件进行定位。结果表明:单个三元次声阵定向误差在2°以内,距离误差约为3.17%(实际的距离为52.74 km,定位误差为1.67 km),定位精度较高,说明提出的时延估计定位方法是可行的。 相似文献
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安全事故的机理分析是山区高速公路施工安全评价的基础,分析了山区高速公路施工安全事故的主要类型,研究了高处坠落事故、物体打击事故、机械伤害事故、触电事故、坍塌事故的产生原因,分析施工安全事故的成因归结为"4M"要素。安全评价指标体系是山区高速公路施工安全评价的关键。结合山区高速公路施工现场实际情况,构建了山区高速公路施工现场安全综合评价指标体系递阶层次结构,从人的因素、物的因素、环境因素、管理因素四个方面深入分析了山区高速公路施工安全评价指标的内涵。 相似文献
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目的 基于图像识别和结构改进对嘴棒发射机运行中产生的横滤嘴棒进行智能剔除、识别和预警,以提高生产效率。方法 采集滤嘴棒侧面运输图像,对异常图像进行追踪,从中提取异常滤嘴棒特征点,基于图像生成警示信息,同时对滤嘴棒发射机输送轨道背板进行结构优化,能剔除大部分横滤嘴棒。结果 改进后的模拟样机,经过输送轨道背板的横滤嘴棒的剔除率高达约77%,其余异常横滤嘴棒被及时预警,嘴棒发射机的管道卡堵概率降低约60%,设备运行效率显著提高。结论 图像识别和结构改进能有效识别预警和剔除嘴棒发射机运行中产生的横滤嘴棒。 相似文献
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随着我国社会主义市场经济的发展,城市化发展水平逐渐加快,使得管道运输成为现代满足能源需求的重要方式,对社会的发展以及国民经济的提升具有重要意义。由于油气管线实际运输过程中存在安全隐患,对油气管理监测中实施光纤预警系统的使用具有重要意义。文章针对光纤预警系统在油气管道检测当中的应用进行实际分析,明确光纤预警的具体设计过程,实现我国管道运输可持续发展。 相似文献
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吴立新 《中国新技术新产品》2015,(1):177
众所周知,山地植被非常茂盛。以江西山区为例,想要造林,就需要一个切实可行的好方法,这样种植下的幼苗才能更好更快的生长。这就需要造林人员高度结合山区气候特点以及其独有的地理特征,因地制宜,选用最适合的科学造林法。本文将结合江西山区的地貌特征,对比播种造林法,对植苗造林法进行分析与研究。 相似文献
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直升机空中救助是一种快速、高效的人命救助方式,山区洪灾因其地形、气象以及人员等因素增加了救助难度和风险,本文结合几次山区救援实例重点讨论山区洪灾救援的特点和方法,供同行参考。 相似文献
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山区公路的特征是,路线随地势走,高低起伏较大,填方路段工作面狭小,基底处理复杂。构造物密集,路基土石方压实困难:土石成分变化频繁,施工中土石方调配必须精打细算。正是因为有了这些特征,才带来了一系列的质量通病,直接影响到公路工程的使用性能和使用安全。 相似文献
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In countries threatened by debris flow disasters, using wireless sensor networks (WSN) for debris flow monitoring and warning has become an important research topic. To detect the initial movement and subsequent moving status of monitored debris or rocks, a two-phase power scheme for a self-developed wireless inertial sensor has been proposed, implemented, and analyzed in this study. During the first phase, the power of the sensor node is disconnected to ensure that the sensor remains stationary. In the second phase, a hybrid scheme with periodic and move-triggered wake-up is actuated if the sensor is moved by debris or hit by rocks. A simple move detection algorithm is used to determine whether the node should enter sleep mode. The power models of the components of the proposed sensor node have also been discussed. Based on those models, the power consumption of the proposed power scheme has been determined and verified according to measurements. Analysis of the proposed hybrid power scheme can be easily generalized for WSN applications with sensor-triggered schemes. The relationship between the moving rate of monitored objects and the wake-up period in the moving detection algorithm was found to be nearly inversely proportional. The results can be employed to estimate and design sensor node power schemes for other similar applications, such as value asset monitoring and tracking. 相似文献
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Andrew T. Tredennick Eamon B. ODea Matthew J. Ferrari Andrew W. Park Pejman Rohani John M. Drake 《Journal of the Royal Society Interface》2022,19(193)
Timely forecasts of the emergence, re-emergence and elimination of human infectious diseases allow for proactive, rather than reactive, decisions that save lives. Recent theory suggests that a generic feature of dynamical systems approaching a tipping point—early warning signals (EWS) due to critical slowing down (CSD)—can anticipate disease emergence and elimination. Empirical studies documenting CSD in observed disease dynamics are scarce, but such demonstration of concept is essential to the further development of model-independent outbreak detection systems. Here, we use fitted, mechanistic models of measles transmission in four cities in Niger to detect CSD through statistical EWS. We find that several EWS accurately anticipate measles re-emergence and elimination, suggesting that CSD should be detectable before disease transmission systems cross key tipping points. These findings support the idea that statistical signals based on CSD, coupled with decision-support algorithms and expert judgement, could provide the basis for early warning systems of disease outbreaks. 相似文献
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跨学科的地质灾害预警工程 总被引:6,自引:0,他引:6
滑坡、泥石流等地质灾害受多种因素的影响,地质灾害预报警报工程体系的建立需要多部门、多学科的合作。2003年6月1日中国气象局和国土资源部联合启动了全国地质灾害气象预警业务,取得了很好的社会和经济效益。分析了我国滑坡泥石流等地质灾害的时空分布特点及其与降雨等多因素、多学科的关系。介绍了国家级地质灾害预报警报业务系统的有关技术,并分析了存在的问题,结合国内外的技术发展现状和趋势,提出了从地球系统5大圈层相互作用的角度研究地质灾害,建立多学科多部门合作的地质灾害监测、预报、警报和防治体系等建议。 相似文献
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At present, associated flow rule of traditional plastic theory is adopted in the slip line field theory and upper bound method of geotechnical materials. So the stress characteristic line conforms to the velocity line. It is proved that geotechnical materials do not abide by the associated flow rule. It is impossible for the stress characteristic line to conform to the velocity line. Generalized plastic mechanics theoretically proved that plastic potential surface intersects the M-C yield surface with an angle, so that the velocity line must be studied by non-associated flow rule. According to limit analysis theory, the theory of slip line field is put forward in this paper, and then the ultimate bearing capacity of strip footing is obtained based on associated flow rule and the non-associated flow rule individually. These two results are identical since the ultimate bearing capacity is independent of flow rule. On the contrary, the velocity fields of associated and non-associated flow are different which shows the velocity field based on the associated flow rule is incorrect. 相似文献
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This paper addresses finite-capacity planning (or medium-term scheduling) issues in a flexible flow line such as a semiconductor fabrication (Fab), liquid crystal display (LCD) Fab, or printed circuit board (PCB) Fab. In such a flexible flow line, medium-term schedules such as release schedules and output schedules are critical to achieving the goal of full-capacity and on-time production. However, existing finite-capacity planning methods do not adequately reflect the actual capacity profiles of the Fab. This paper presents capacity-filtering algorithms for generating a finite-capacity loading-profile from an infinite-capacity loading-profile at a processing stage in a Fab. In addition, two types of finite-capacity planning problems are described, and ways to use the algorithms in solving these problems presented. Performance analyses using a real-life case study show that the proposed method is superior to existing methods. It is postulated that the results presented can be used as a building block for obtaining medium-term schedules for the entire Fab. 相似文献
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青藏高原“敏感区”对我国灾害天气气候的影响及其监测 总被引:2,自引:0,他引:2
根据中国区域大范围洪涝、暴雨、暴雪天气预报上游关键区,以及气候变化敏感区多圈层信息平台等重大需求.从"世界屋脊"青藏高原为灾害性天气上游关键区与气候信号敏感区的观点出发,提出高原及周边观测工程建网新思路与应用新技术方案,设计、构建了新一代气象综合观测预警长期监测系统,实现科学试验-工程建设-工程应用开发途径,发展高原及周边敏感区灾害天气上游早期预警系统监测平台,为灾害性天气预报与区域气候变化提供多功能业务服务应用平台;采用高原东缘南-北轴向观测数据信息(GPS监测站与AWS站)应用于改进WRF(weather research and forecasts)模式三维变分方案,实现了模式优化站网信息的同化技术,可提升中国区域暴雨、南方雪灾模式预报能力.针对夏季暴雨、南方暴雪,检验、证明了高原观测工程布网"早期预警"的显著效果. 相似文献
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基于非关联流动法则的滑移线场及上限法研究 总被引:2,自引:0,他引:2
当前岩土材料的滑移线场理论及上限法中都广泛采用经典塑性理论中的关联流动法则,由此得出应力特征线与速度滑移线一致的结论。而试验得知,岩土材料并不服从关联流动法则,因而应力特征线与速度滑移线不可能重合。文章分析了基于关联流动法则的滑移线场及上限法中存在的问题,根据广义塑性理论推导了基于非关联流动法则的滑移线场及上限法,消除了现行滑移线场理论及上限法理论中的种种矛盾。 相似文献
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V. A. Uvarova S. V. Khlyst R. M. Rozhenok L. V. Artyukhina 《Measurement Techniques》2007,50(7):782-787
The problems that arise in comprehensive automation of production are considered. Characteristics are given and examples are
provided of intellectual measurement provisions and control, information measurement systems, and software/hardware suites
used in enterprises of the chemical, mining, petrochemical, metallurgical, and oil processing industries. A version of implementing
a system for production management is demonstrated.
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Translated from Izmeritel’naya Tekhnika, No. 7. pp. 59–62, July, 2007. 相似文献
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监控系统在工业生产和日常生活中有着广泛的应用,设计了一种采用嵌入式处理器与嵌入式操作系统相结合的音视频监控系统。系统硬件平台由CCD图像传感器、GO7007SB视频编码器、S3C2410嵌入式处理器组成,负责视频数据的采集和MPEG-4压缩编码;软件平台采用Windows CE 5.0作为操作系统,软件实现了数据流的RTP封装和发送。详细论述了系统设计、硬件设计和软件设计,实际运行效果表明该系统稳定可靠,能较好地满足监控要求。此设计架构可大大降低开发难度,缩短开发周期,具有很好的可维护性和性价比。 相似文献