Intelligent Detection and Recovery of Missing Electric Load Data Based on Cascaded Convolutional Autoencoders

Under the background of Energy Internet, the ever-growing scale of the electric power system has brought new challenges and opportunities. Numerous categories of measurement data, as the cornerstone of communication, play a crucial role in the security and stability of the system. However, the present sampling and transmission equipment inevitably suffers from data missing, which seriously degrades the stable operation and state estimation. Therefore, in this paper, we consider the load data as an example and first develop a missing detection algorithm in terms of the absolute difference sequence (ADS) and linear correlation to detect any potential missing data. Then, based on the detected results, we put forward a missing recovery model named cascaded convolutional autoencoders (CCAE), to recover those missing data. Innovatively, a special preprocessing method has been adopted to reshape the one-dimensional load data as a two-dimensional matrix, and hence, the image inpainting technologies can be conducted to address the problem. Also, CCAE is designed to reconstruct the missing data grade by grade due to its priority strategy, which enhances the robustness upon extreme missing situations. The numerical results on the load data of the Belgium grid validate the promising performance and effectiveness of the proposed solutions

The components of <i>M</i>. <i>bracteata</i> leaves ethanol extract.

<p>The components of <i>M</i>. <i>bracteata</i> leaves ethanol extract.</p

Optimization of Extraction Conditions for Maximal Phenolic, Flavonoid and Antioxidant Activity from <i>Melaleuca bracteata</i> Leaves Using the Response Surface Methodology

<div><p><i>Melaleuca bracteata</i> is a yellow-leaved tree belonging to the <i>Melaleuca</i> genus. Species from this genus are known to be good sources of natural antioxidants, for example, the “tea tree oil” derived from <i>M</i>. <i>alternifolia</i> is used in food processing to extend the shelf life of products. In order to determine whether <i>M</i>. <i>bracteata</i> contains novel natural antioxidants, the components of <i>M</i>. <i>bracteata</i> ethanol extracts were analyzed by gas chromatography–mass spectrometry. Total phenolic and flavonoid contents were extracted and the antioxidant activities of the extracts evaluated. Single-factor experiments, central composite rotatable design (CCRD) and response surface methodology (RSM) were used to optimize the extraction conditions for total phenolic content (TPC) and total flavonoid content (TFC). Ferric reducing power (FRP) and 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging capacity were used as the evaluation indices of antioxidant activity. The results showed that the main components of <i>M</i>. <i>bracteata</i> ethanol extracts are methyl eugenol (86.86%) and <i>trans</i>-cinnamic acid methyl ester (6.41%). The single-factor experiments revealed that the ethanol concentration is the key factor determining the TPC, TFC, FRP and DPPH·scavenging capacity. RSM results indicated that the optimal condition of all four evaluation indices was achieved by extracting for 3.65 days at 53.26°C in 34.81% ethanol. Under these conditions, the TPC, TFC, FRP and DPPH·scavenging capacity reached values of 88.6 ± 1.3 mg GAE/g DW, 19.4 ± 0.2 mg RE/g DW, 2.37 ± 0.01 mM Fe²⁺/g DW and 86.0 ± 0.3%, respectively, which were higher than those of the positive control, methyl eugenol (FRP 0.97 ± 0.02 mM, DPPH·scavenging capacity 58.6 ± 0.7%) at comparable concentrations. Therefore, the extracts of <i>M</i>. <i>bracteata</i> leaves have higher antioxidant activity, which did not only attributed to the methyl eugenol. Further research could lead to the development of a potent new natural antioxidant.</p></div

A mitogenomic phylogeny of spiders and complete mitochondrial genome of Cyriopagopus hainanus (Araneae:Theraphosidae)

We describe the complete mitochondrial genome sequence of Cyriopagopus hainanus, a spider in the family of Theraphosidae and endemic to Hainan Island, China. Phylogenetic analyses using mitogenomes of 32 spider species from 20 families strongly supported our sample is sister to Cyriopagopus schmidti. This is also the largest mitogenomic phylogeny of spiders to date. The mitogenomic length of C. hainanus is 13,874 bp, including 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 control region. The complete mitochondrial genome of C. hainanus will contribute to studies of mitogenomic evolution and trait evolution in spiders

Effects of concentration, time and temperature on TPC, TFC, FRP and DPPH· scavenging capacity.

<p>(A) ethanol concentration (<i>T</i> = 50°C, Time = 3 d), (B) Extraction time (Ethanol = 40%, T = 50°C), (C) Extraction temperature (Ethanol = 40%, Time = 3 d).</p

Experimental and predicted values of evaluation indices extracted under the same conditions.

<p>Experimental and predicted values of evaluation indices extracted under the same conditions.</p

Empiric second-order polynomial model of TPC, TFC, FRP and DPPH• scavenging capacity.

<p>Empiric second-order polynomial model of TPC, TFC, FRP and DPPH• scavenging capacity.</p

GC-MS spectrometry of <i>M</i>. <i>bracteata</i> leaves ethanol extract.

<p>GC-MS spectrometry of <i>M</i>. <i>bracteata</i> leaves ethanol extract.</p

Experimental and predicted values of each evaluation index under optimal conditions.

<p>Experimental and predicted values of each evaluation index under optimal conditions.</p