Detection of Outliers in Sensor Data Based on Adaptive Moving Average Fitting

Xiong, Jianguo; Wang, Qinruo; Wan, Jiafu; Ye, Baoyu; Xu, Weichao; Zhang, Jian

doi:10.1166/sl.2013.2657

Cited by 9 publications

(4 citation statements)

References 2 publications

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“…The EC values recorded by the data logger were transferred to a computer and sorted in .xlsx format. After moving average processing [38,39] to reduce accidental error in the recorded data, the data with monitoring frequencies of 30 min were screened by using Microsoft Excel 2019. Finally, the EC values were converted into ammonium N concentrations (Formulas 1 and 2).…”

Section: Discussionmentioning

confidence: 99%

Performance of an Automatic Variable-Rate Fertilization System Subject to Different Initial Field Water Conditions and Fertilizer Doses in Paddy Fields

Wang,

Xu,

Chen

et al. 2023

Agronomy

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High-performance fertilization equipment with high uniformity is essential for the improvement of fertilizer use efficiency in paddies. The performance of these fertigation systems might be affected by the initial field conditions and fertilizer doses. In this study, the uniformity of fertilization by an automatic system (SF) was investigated; the investigation had two initial field water conditions and fertilizer doses, and manual fertilization by farmers (FF) was used as the control. After fertilization, the Christiansen uniformity coefficient (CU) in the SF paddies was higher than in the FF paddies, and the SF in the non-flooded paddies (SFN) was the highest. With time, the CU of treatments with poor fertilization uniformity was improved; it was driven by the osmotic potential of fertilizer ions, but it was far from exceeding that of the treatments originally conducted with higher CU. For the SF treatments, the fertilizer dose did not affect fertilization uniformity significantly; so, an SF can match the efficient fertilization strategies more precisely. As water-saving irrigation (WSI) is conducive to the production of non-flooded field conditions and the promotion of the efficient use of topdressing, the use of automatic fertilization systems to implement efficient fertilization management practices in WSI paddy fields is suggested.

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Section: Discussionmentioning

confidence: 99%

Performance of an Automatic Variable-Rate Fertilization System Subject to Different Initial Field Water Conditions and Fertilizer Doses in Paddy Fields

Wang,

Xu,

Chen

et al. 2023

Agronomy

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“…In this article, we use a sliding time window derived from the moving average to extract the local maximums of

δ_{k} true(k = 1, \dots, K - 1 true)

, which are considered to be switch points . The phase partition procedure consists of the following steps, which are also illustrated in Figure : Determine the length of the time window s , the step size of the time window L , which satisfies (

L < s

), and the total step that is denoted as count .…”

Section: Methodsmentioning

confidence: 99%

Online prediction of quality‐related variables for batch processes using a sequential phase partition method

Wang

Gao

et al. 2019

Can J Chem Eng

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Batch processes inherently have multiple operation phases; different phases exhibit different characteristics. Hence, it is reasonable to partition the process into phases and build sub‐phase models for online quality prediction. To this end, a sequential phase partition method based on the information increment is proposed. To address the multiphase behaviours in batch processes, this work utilizes a new information increment index to capture the dynamic characteristics of batch processes along a time direction and divides the process into sub‐phases. Next, phase‐based multiway partial least squares (MPLS) models are built to model within‐phase characteristics and predict the quality‐related variables online. Information increment is able to exploit the process evolution by focusing on the changing variable correlations derived from two adjacent extend time slice. It directly utilizes the available process measurements of successful history batch processes without data transformation or dimensionality reduction. The method is sequential and can overcome the limits of some phase partition methods that may divide the samples with discontinuous time sequence but similar characteristics into the same phase. In addition, the information increment is capable of reflecting the change of the process intuitively with high computation efficiency. Advantages of the proposed method are illustrated by two case studies, a penicillin simulation platform and an industrial application of Escherichia coli (E. coli) fermentation, respectively.

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“…Accordingly, removing outliers in the GNSS time series will speed up processing. Several popular algorithms, such as moving average (Xiong et al, 2013), generalized extreme studentized deviation (Martel, 2016), quartiles (Vinutha et al, 2018), moving median (Zhang et al, 2019), and Grubbs (Aslam, 2020), can be employed for outlier removal. Among these, the moving median algorithm proved optimal, demonstrating sensitivity to noise while maintaining robustness and unbiased to anomalies (Le et al, 2021).…”

Section: Discontinuity-correction Techniquementioning

confidence: 99%

Identifying Neotectonic Motions in Germany Using Discontinuity-corrected GNSS Data

Le,

Männel,

Bui

et al. 2023

Preprint

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The crustal motions throughout Germany have not yet been fully understood because the research scope of previous studies often focuses only on some active grabens. Thus, we investigate it in detail to identify the neotectonic motion characteristics and specific deformation-ongoing regions. High accuracy for monitoring and data analyses is required because the expected crustal deformation in Germany is small. For this reason, we use high-precision GNSS time series processing techniques and interdisciplinary data to reflect actual motions and determine the causes of deformation. Also, an advanced technique of discontinuity correction is introduced to unify the fragments of the GNSS coordinate time series for better velocity field reliability. Our findings show that the crustal motions in Germany tend to increase at a maximum speed of +1.0 mm/yr. Meanwhile, local subsidence of around -0.8 mm/yr is concentrated in the river basins (e.g., the Rhine, Ems, Elbe, Northern Oder, and Danube) and extensive mining regions. The Earth's crust here also behaves with noticeable compressions. The intra-plate motion in Germany is ~0.8 mm/yr. A special region with an extension rate of +4.3 nstrain/yr is observed along the North-South trending Regensburg-Leipzig-Rostock shear zone. Machine Learning clusters the 3D plate velocity field in Germany into three distinct regions with increasing speeds: Northwest, East, and Southwest. Significant surface deformations are detected mainly in the Upper Rhine graben, Eifel volcanic field, and Thuringian-Vogtland slate mountains. The harmonic motions of the Earth's crust in Germany have an amplitude of ~4.7 mm, in which the surface loads contribute half to this type of motion. The findings will contribute to the overall picture of neotectonics here.

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Detection of Outliers in Sensor Data Based on Adaptive Moving Average Fitting

Cited by 9 publications

References 2 publications

Performance of an Automatic Variable-Rate Fertilization System Subject to Different Initial Field Water Conditions and Fertilizer Doses in Paddy Fields

Performance of an Automatic Variable-Rate Fertilization System Subject to Different Initial Field Water Conditions and Fertilizer Doses in Paddy Fields

Online prediction of quality‐related variables for batch processes using a sequential phase partition method

Identifying Neotectonic Motions in Germany Using Discontinuity-corrected GNSS Data

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