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51.
YAO Shuren WANG Mingyu SHU Lifu TIAN Xiaorui LI JieInstitute of Forest Protection. Chinese Academy of Forestryfire @forestry ac. cn Forest fire manaeement office. State Forestry Administration 《中国林业科技(英文版)》2003,(3)
Remote sensing as the measure to monitor disasters has the advantage of temporal resolution and large scale. Since "5.6 catastrophe" in 1987, China began to monitor forest fires broadly. In the summer of 2002, many forest/grass fires occurred in the Daxing'anling Mountains, and the damage was very heavy. In the forest fires fighting, the meteorological satellites play an important role in monitoring the fires. Especially the FY serial meteorological satellites have the advantage of large scale monitoring and characteristics of being in time and exact, and get good results. Remote sensing techniques have been used in many aspects of forest/grass fires research, including burned area and fireline intensity evaluation, post fire environment monitoring etc. 相似文献
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本文给出了不等间隔时序数列的CM(1,1)模型,并对广西融水县森林资源动态变化进行了预测。预测结果比较理想,模型精度97.2%,从而为森林资源部分数据更新提供了一个新方法。 相似文献
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机械臂连杆柔性、关节柔性等非线性变形的综合影响,导致其末端位置发生偏离而产生误差。本文以IRB1410型串联机械臂为研究对象,采用理论分析、仿真分析与实验验证相结合的方式,对机械臂末端位置误差进行分析与补偿研究。首先,建立机械臂刚柔耦合理论误差模型,并运用Newmarkβ法进行数值仿真分析;联合ANSYS和ADAMS进行刚柔耦合机械臂末端位置运动误差仿真;为了实现快速补偿,提出基于BP神经网络的伪目标点法对位置误差进行补偿,补偿后其位置误差均方根减小了68.3%,说明该方法具有较好的补偿效果;最后,自主设计并搭建了测量实验平台,采用所提算法进行了误差补偿实验,对比补偿前后距离误差,补偿后误差均方根减小了77.01%,验证了伪目标点法对柔性误差补偿的有效性。 相似文献
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精准网络通信理念在智能作物收获机中的应用 总被引:1,自引:0,他引:1
为进一步提高作物收获机的智能通信水平,从精准网络理念角度出发对其通信系统展开研究。全面理解智能收获机一站式的集中收获作业机理,考虑车辆运动的非线性特点及收获执行部件(摘辊系统及相连接组件等)运动参数与作物收获破损关系,搭建该类型智能化作物收获机的精准网络通信控制模型,运用数据传感融合核心算法,针对通信系统硬件配置及软件控制驱动进行设计,并进行通信系统应用试验。试验结果表明:收获机速度、高度设定数值与通信装置监测传输误差分别为5.33%、2.12%,执行部件转速、位置设定与通信系统监测传输误差分别为2.57%、7.27%,均控制在7.5%之内,满足收获机的控制与通信精度要求。 相似文献
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Friedrich Ladich 《Fish and Fisheries》2022,23(1):227-238
Predation is a major ecological constraint shaping behaviour and communication in animals. Several fish species are known to modify their foraging, agonistic and reproductive behaviour in the presence of predators. However, close to nothing is known about how predators affect sound production in fishes. This paper reviews how vocal fish increase their chance of survival by modifying intraspecific acoustic communication and by producing sounds directed towards predators. Field studies showed that toadfish, drums and squirrelfish reduced the number and loudness of calls when dolphin sounds were played back. These studies lack behavioural observations, leaving the question open how individual fish respond to predation threat. Croaking gouramis (Trichopsis vittata, Osphronemidae) reduced acoustic and visual signalling during dyadic contests and refrained from escalated behaviour when detecting a predator in an adjacent tank. This indicates that gouramis increase their vigilance by reducing agonistic behaviour. Vocal fish have been observed to emit sounds when predators approach or when being caught. However, none of the predators (or even conspecifics nearby) responded to these calls. Therefore, the term “predator-related” sound has been introduced in this paper to avoid implying unproven functions (alarm, startling, warning, distress and disturbance). Interestingly, the readiness of numerous taxa (e.g. catfishes) to vocalize when hand-held or netted was frequently exploited to investigate sound production in fish in relation to weight, sex, sonic organs, temperature or phylogeny. Increasing levels of noise in aquatic habitats call for more research on predator–prey interactions because of potential negative effects on detection of sounds produced by predators or prey. 相似文献
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婚庆视觉传达有其独特的艺术特征,具有强大的设计开发潜力。随着市场经济的发展,适婚人群把更多视线投向了婚庆的视觉传达设计。未来婚庆视觉传达设计逐渐呈现出个性与时尚化、数字与多样化、系列与品牌化、情感与民族化、功能与环保化的发展趋势。 相似文献
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