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71.
72.
The impact of misregistration on SRTM and DEM image differences 总被引:2,自引:0,他引:2
Thomas G. Van Niel Tim R. McVicar LingTao Li John C. Gallant QinKe Yang 《Remote sensing of environment》2008,112(5):2430-2442
Image differences between Shuttle Radar Topography Mission (SRTM) data and other Digital Elevation Models (DEMs) are often performed for either accuracy assessment or for estimating vegetation height across the landscape. It has been widely assumed that the effect of sub-pixel misregistration between the two models on resultant image differences is negligible, yet this has not previously been tested in detail. The aim of this study was to determine the impact that various levels of misregistration have on image differences between SRTM and DEMs. First, very accurate image co-registration was performed at two study sites between higher resolution DEMs and SRTM data, and then image differences (SRTM–DEM) were performed after various levels of misregistration were systematically introduced into the SRTM data. It was found that: (1) misregistration caused an erroneous and dominant correlation between elevation difference and aspect across the landscape; (2) the direction of the misregistration defined the direction of this erroneous and systematic elevation difference; (3) for sub-pixel misregistration the error due solely to misregistration was greater than, or equal to the true difference between the two models for substantial proportions of the landscape (e.g., greater than 33% of the area for a half-pixel misregistration); and (4) the strength of the erroneous relationship with aspect was enhanced by steeper terrain. Spatial comparisons of DEMs were found to be sensitive to even sub-pixel misregistration between the two models, which resulted in a strong erroneous correlation with aspect. This misregistration induced correlation with aspect is not likely specific to SRTM data only; we expect it to be a generic relationship present in any DEM image difference analysis. 相似文献
73.
A multi-objective controller synthesis problem is considered in which an output is to be regulated approximately by assuring a bound on the steady-state peak amplification in response to an infinite-energy disturbance, while also guaranteeing a desired level of performance measured in terms of the worst-case energy gain from a finite-energy input to a performance output. Relying on a characterization of the controllers with which almost asymptotic regulation is accomplished, the problem of guaranteeing the desired level of performance is reduced to solving a system of linear matrix inequalities subject to a set of linear equality constraints. Based on the solution of this system, a procedure is outlined for the construction of a suitable controller whose order is equal to the order of the plant plus the order of the exogenous system. 相似文献
74.
基于ARM的混凝土搅拌站自动控制系统 总被引:1,自引:0,他引:1
根据混凝土搅拌站的实际情况和配料设备对配料控制系统的性能要求,本文主要介绍了一种混凝土搅拌站自动控制系统,提出了以工控机为上位机,以集成度高,运行速度快,抗干扰性能好的LPC2114嵌入式控制器为下位机的总体设计方案,讨论了配料控制器的设计原则,介绍了硬件系统设计、软件系统设计和称重配料控制算法,提供了一种实用的搅拌站自动控制系统解决方案。该系统工作稳定可靠、智能化程度高、配料精度高。 相似文献
75.
船舶蒸汽动力装置自动控制的首要任务是机组的负荷控制。传统的PID控制算法由于具有结构简单、易于实现、可消除静差等优点得到了广泛的应用,但它受控制对象的影响较大,只有在各参数整定良好的前提下才能得到满意的控制效果。根据上述情况,结合船舶蒸汽动力单元工况变化频繁的特点,提出一种基于输出响应的自适应PID算法,以提高控制系统适应负荷变化的能力。方法在保留传统定值PID控制算法优点的同时,引入模糊控制在线整定PID控制参数,改善了机组的负荷控制特性,具有一定的工程应用价值. 相似文献
76.
In this paper, we present an analysis and synthesis approach for guaranteeing that the phase of a single-input, single-output closed-loop transfer function is contained in the interval [−α,α] for a given α>0 at all frequencies. Specifically, we first derive a sufficient condition involving a frequency domain inequality for guaranteeing a given phase constraint. Next, we use the Kalman–Yakubovich–Popov theorem to derive an equivalent time domain condition. In the case where , we show that frequency and time domain sufficient conditions specialize to the positivity theorem. Furthermore, using linear matrix inequalities, we develop a controller synthesis approach for guaranteeing a phase constraint on the closed-loop transfer function. Finally, we extend this synthesis approach to address mixed gain and phase constraints on the closed-loop transfer function. 相似文献
77.
在EPA组态软件的设计中,工程管理模块贯穿着整个软件的运行。针对EPA网络的特点,将在线的EPA设备作为一个EPA工程,并通过该工程管理设备的运行状态。实验结果表明,该设计方法能有效地控制现场的EPA设备。 相似文献
78.
A country’s economy heavily depends on agricultural development. However, due to several plant diseases, crop growth rate and quality are highly suffered. Accurate identification of these diseases via a manual procedure is very challenging and time-consuming because of the deficiency of domain experts and low-contrast information. Therefore, the agricultural management system is searching for an automatic early disease detection technique. To this end, an efficient and lightweight Deep Learning (DL)-based framework (E-GreenNet) is proposed to overcome these problems and precisely classify the various diseases. In the end-to-end architecture, a MobileNetV3Small model is utilized as a backbone that generates refined, discriminative, and prominent features. Moreover, the proposed model is trained over the PlantVillage (PV), Data Repository of Leaf Images (DRLI), and a new Plant Composite (PC) dataset individually, and later on test samples, its actual performance is evaluated. After extensive experimental analysis, the proposed model obtained 1.00%, 0.96% and 0.99% accuracies on all three included datasets. Moreover, the proposed method achieves better inference speed when compared with other State-Of-The-Art (SOTA) approaches. In addition, a comparative analysis is conducted where the proposed strategy shows tremendous discriminative scores as compared to the various pre-trained models and other Machine Learning (ML) and DL methods. 相似文献
79.
选煤厂自动控制系统的实现 总被引:1,自引:0,他引:1
介绍了选煤厂自动控制系统的组成和具体设计,阐述了系统关键功能的实现。实际应用表明,该系统实现了选煤厂各个环节的自动控制功能,安全可靠、可扩展性强。 相似文献
80.