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Advancing enterprise credit rating through multi-head self-attention and transfer learning
(2026-01-01)
Zhang, Rui
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Li, Qing
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Chen, Jiangchuan
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Li, Jie
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Sakdanuphab, Rachsak
This study introduces the multi-head self-attention rotary-positional encoding Informer (MHSA-RPEI), a novel enterprise credit rating model that leverages self-correlation weights and positional information of financial indicators to enhance rating accuracy. Corporate credit rating presents challenges such as temporal dynamics, complex non-linear relationships, and cross-regional variations, which traditional and deep learning models struggle to address. The MHSA-RPEI model overcomes these limitations through four innovations: (1) objective MHSA-RPEI model, which is specifically designed for credit rating, achieving high precision using only financial data and serving as an objective and validated tool; (2) revolutionary rotary positional encoding (RoPE), which enhances temporal modeling, improving dynamic risk assessment; (3) strategic transfer learning (TL), which facilitates cross-regional adaptations, mitigating data scarcity and domain variations; and (4) optimized informer architecture, which improves long-term risk forecasting based on extensive financial time series. Experiments on the U.S., Chinese, and Japanese financial data showed that MHSA-RPEI achieved 92.16% accuracy (U.S.), 90.32% (China), and 92.50% (Japan), with area under the receiver operating characteristic curve scores ranging from 88.47% to 91.95%, surpassing traditional and state-of-the-art models. Furthermore, TL experiments highlighted the exceptional adaptability of the MHSA-RPEI for cross-regional applications, yielding performance gains of 5–6%. Ablation studies confirmed that the RoPE and self-correlation weight modules were crucial to the effectiveness of the model.
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Crystal structure, microwave dielectric properties and antenna simulation of low-permittivity Eu2CaMGa4O12(M = Ti, Sn, Zr) garnets
(2025-12-01)
Yang, Yang
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Wang, Zhaohui
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Qiu, Huizi
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Fang, Weishuang
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Tang, Ying
The rattling of cations plays a vital role in energy loss mechanisms and is a fundamental approach for tuning dielectric performance. In this work, phase-pure garnets with the general formula Eu<inf>2</inf>CaMGa<inf>4</inf>O<inf>12</inf> (M = Ti, Sn, Zr) were successfully synthesized. The Eu<inf>2</inf>CaZrGa<inf>4</inf>O<inf>12</inf>, Eu<inf>2</inf>CaSnGa<inf>4</inf>O<inf>12</inf>, and Eu<inf>2</inf>CaTiGa<inf>4</inf>O<inf>12</inf> ceramics were obtained through sintering at 1400°C–1500°C for 6 h. The ceramics sintered at 1450°C exhibited favorable microwave dielectric performance with low ε<inf>r</inf> values of 10.74 (for Sn), 12.34 (for Zr) and 13.66 (for Ti), high Q×f values of 83,500 GHz (for Sn), 72,800 GHz (for Zr) and 59,200 GHz (for Ti), as well as negative τ<inf>f</inf> values of −60.60 ppm/°C (for Sn), −57.20 ppm/°C (for Zr) and −48.20 ppm/°C (for Ti). In Eu<inf>2</inf>CaMGa<inf>4</inf>O<inf>12</inf> (M = Ti, Sn, Zr) ceramics, the “rattling” effect of Eu3+and Ga3+dominated a slight overall structural expansion, which, in turn, led to the higher ε<inf>r</inf> compared to the theoretical prediction (ε<inf>r(C-M)</inf>) and contributed to the negative τ<inf>f</inf>. The variation in the Q × f values of the ceramics exhibited a negative correlation with the FWHM of the A<inf>1g</inf> Raman mode. Furthermore, due to the ultra-low loss of Eu<inf>2</inf>CaSnGa<inf>4</inf>O<inf>12</inf> ceramic, a dielectric resonator antenna was designed. This demonstrates the promising potential of the ceramics for 5G communication applications.
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High-entropy gallium-based garnet microwave dielectric ceramics with low loss for C-band dielectric resonator antenna application
(2025-11-01)
Wen, Xinyang
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Xiang, Huaicheng
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Gu, Xiaolong
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Pulphol, Phieraya
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Vittayakorn, Naratip
In this work, (Y<inf>0.5</inf> Nd<inf>0.5</inf> Sm<inf>0.5</inf> Eu<inf>0.5</inf> Ho<inf>0.5</inf> Yb<inf>0.5</inf> )Ga<inf>5</inf> O<inf>12</inf> high-entropy ceramic with a cubic garnet structure was designed and synthesized via a solid-state reaction method. Through the high-entropy regulation of the oxygen dodecahedron, the bond strength increases, the cation's bond valence approaches the ideal value, and the structural stability improves, thereby promoting the Q × f value. Low dielectric loss (Q × f = 130,100 GHz) was obtained in the high-entropy ceramic (Y<inf>0.5</inf> Nd<inf>0.5</inf> Sm<inf>0.5</inf> Eu<inf>0.5</inf> Ho<inf>0.5</inf> Yb<inf>0.5</inf> )Ga<inf>5</inf> O<inf>12</inf> , which exhibited a low relative permittivity (ε<inf>r</inf> ) of 12.36, a negative temperature coefficient of resonant frequency (τ<inf>f</inf> ) of −66.37 ppm/°C, and a high flexural strength of 229.68 MPa. Furthermore, a cylindrical dielectric resonator antenna (CDRA) was designed featuring high radiation efficiency (>90 %) and stable gain (5.91–5.97 dBi) within a 255 MHz bandwidth, showing promising application prospects in the C-band. This work indicates that the high-entropy strategy is feasible for the design of high-performance microwave dielectric ceramics.
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Direct and indirect effects and feedbacks of biomass burning aerosols over Mainland Southeast Asia and South China in springtime
(2022-10-10)
Li, Jiawei
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Han, Zhiwei
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Surapipith, Vanisa
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Fan, Wenxuan
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Thingboonchoo, Narisara
Southeast Asia is one of the largest biomass burning (BB) source regions in the world. In order to promote our understanding of BB aerosol characteristics and environmental impacts, this study investigated the emission, composition, evolution, radiative effects, and feedbacks of BB aerosols from Mainland Southeast Asia during 15 March to 15 April 2019 by using an online-coupled regional chemistry/aerosol-climate model RIEMS-Chem. Model results are compared against a variety of ground and vertical observations, indicating a generally good model performance for meteorology, aerosol chemical compositions, and aerosol optical properties. It is found that BB aerosols contributed significantly to regional particulate matter (PM), accounting for up to 90 % of the near-surface PM<inf>2.5</inf>, BC, and OC concentrations over the BB source regions of north Mainland Southeast Asia and for approximately 30–70 % over wide downwind areas including most areas of southwest China and portions of south China. At the top of atmosphere (TOA), BB aerosols exerted a positive all-sky radiative effect (DRE<inf>BB</inf>) up to 25 W/m2 over north Vietnam and south China, a negative DRE<inf>BB</inf> up to −10 W/m2 over Myanmar, western Thailand, and southwest China. Meanwhile, the indirect radiative effect (IRE<inf>BB</inf>) was consistently negative, with the maximum of −10 W/m2 over downwind areas with cloud coverage, e.g., from north Vietnam to most of south China. The subregional (95–125°E and 10–30°N) and period mean DRE<inf>BB</inf> and IRE<inf>BB</inf> at TOA were estimated to be 0.69 W/m2 and − 0.63 W/m2, respectively, leading a total radiative effect (TRE<inf>BB</inf>) of 0.06 W/m2 at TOA. The radiative effects of BB aerosols led to decreases in sensible and latent heat fluxes, near-surface temperature, PBL height, and wind speed of 6.0 Wm−2, 9.0 Wm−2, 0.26 °C, 38.7 m, and 0.1 m/s, respectively, accompanied with an increase in RH of 1.9 %, averaged over the subregion and the study period. The accumulated precipitation during the study period was apparently reduced by BB aerosols from east Thailand to south China, with the maximum reduction up to 14 cm (exceeding 40 %) over north Vietnam and south China. TRE<inf>BB</inf> tended to increase mean near-surface PM<inf>2.5</inf> and its component concentrations, with the maximum percentage increase up to 24 % over the BB source regions of north Mainland Southeast Asia, resulting from the combined effects of dynamic and chemical feedbacks. DRE<inf>BB</inf> generally dominated over IRE<inf>BB</inf> in the feedback-induced PM<inf>2.5</inf> concentration changes.

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