Design of High Temperature Complex Dielectric Properties Measuring System Based on XGBoost Algorithm

Abstract

This paper aims to propose an online relative complex permittivity measurement system at high temperature based on microwave interferometer. A ridge waveguide with a TE10 mode was used in which the sample was heated and measured simultaneously at a frequency of 2450 MHz, and the microwave interferometer is used to collect the amplitude and phase difference of the incident signal. The Extreme Gradient Boosting (XGBoost) algorithm trained by the corresponding simulation data is used to construct the inversion model to calculate the complex dielectric coefficient of the tested material. Besides, this paper uses linear regression algorithm (LR) to calibrate the measurement system in order to improve the measurement accuracy. The entire system was tested using different materials at room temperature, and the maximum error of the measurement accuracy is less than 8% compared to the theoretical data. The robustness of the entire system was also tested by measuring Macor materials up to 800 °C. This proposed method provides an effective way to understand the mechanism between microwaves and matter at high temperatures.

Integrative analysis of DNA methylomes reveals novel cell-free biomarkers in lung adenocarcinoma

“…In the training phase, CpGs in the 725 LUAD DMRs and DMCs of the discovery cohort were trained with LUAD cohorts based on analyses with the Illumina Infinium HumanMethylation450 BeadChip collected from The Cancer Genome Atlas (TCGA-LUAD, https://cancergenome.nih.gov/) and the Gene Expression Omnibus (GEO) dataset. XGBoost algorithm (Wang et al, 2020;Wu et al, 2020) was performed subsequently to identify LUAD-specific CpGs with an important score >0.1. In our XGBoost model, we employed gradient tree boosting algorithm, a special form of gradient boosting machine and predicting, by combining the results of multiple weak learners.…”