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710 results on '"Zhang, Yanxia"'

3. Efficient Identification of Broad Absorption Line Quasars using Dimensionality Reduction and Machine Learning

Author

Kao, Wei-Bo, Zhang, Yanxia, and Wu, Xue-Bing

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

Broad Absorption Line Quasars (BALQSOs) displaying distinct blue-shifted broad absorption lines. These serve as invaluable probes for unraveling the intricate structure and evolution of quasars, shedding light on the profound influence exerted by supermassive black holes on galaxy formation. The proliferation of large-scale spectroscopic surveys such as LAMOST, SDSS, and DESI has exponentially expanded the repository of quasar spectra at our disposal. In this study, we present an innovative approach to streamline the identification of BALQSOs, leveraging the power of dimensionality reduction and machine learning algorithms. Our dataset is curated from the SDSS DR16, amalgamating quasar spectra with classification labels sourced from the DR16Q quasar catalog. We employ a diverse array of dimensionality reduction techniques, including Principal Component Analysis (PCA), t-Distributed Stochastic Neighbor Embedding (t-SNE), Locally Linear Embedding (LLE), and Isometric Mapping (ISOMAP), to distill the essence of the original spectral data. The resultant low-dimensional representations serve as inputs for a suite of machine learning classifiers, including XGBoost and Random Forest models. Through experimentation, we unveil PCA as the most effective dimensionality reduction methodology, adeptly navigating the intricate balance between dimensionality reduction and preservation of vital spectral information. Notably, the synergistic fusion of PCA with the XGBoost classifier emerges as the pinnacle of efficacy in the BALQSO classification endeavor, boasting impressive accuracy rates of 97.60% by 10-cross validation and 96.92% on the outer test sample. This study not only introduces a novel machine learning-based paradigm for quasar classification but also offers invaluable insights transferrable to a myriad of spectral classification challenges pervasive in the realm of astronomy., Comment: 17 pages, 6 figures, accepted for publication in PASJ

Published
2024
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12. Clinical effect of compound azintamide combined with bifidobacteria triple viable capsules in the prevention and treatment of antibiotic-associated diarrhea in the elderly

Author

ZHANG Yanxia, GUO Zongjun, REN Lijuan, LIU Lei

Subjects
diarrhea, compound azamite, anti-bacterial agents, prevention and therapy, drug-related side effects and adverse reactions, bifidobacterium, treatment outcome, aged, Medicine
Abstract

Objective To investigate the clinical effect and mechanism of compound azintamide combined with bifidobacteria triple viable capsules in the prevention and treatment of antibiotic-associated diarrhea (AAD) in the elderly. Methods A retrospective analysis was performed for 62 elderly patients with or comorbid with infectious diseases who were admitted to Department of Geriatrics, Taian 88 Hospital, from October 2019 to February 2021 and received intravenous drip of antibiotics, and according to the treatment method, they were divided into observation group with 32 patients (treated with compound azintamide combined with bifidobacteria triple viable capsules) and control group with 30 patients (treated with bifidobacteria triple viable capsules alone). The drugs were used in addition to antibiotics for 14 d. The two groups were compared in terms of the incidence rate of AAD, time to the onset of diarrhea, number of times of diarrhea per day, and duration of diarrhea during treatment, as well as related biochemical parameters before treatment and on day 14 of treatment, including hemoglobin (Hb), plasma albumin (Alb), total protein (TP), and the serum levels of C-reactive protein (CRP), interleukin-6 (IL-6), and complement C3 and C4. Results Compared with the control group, the observation group had a significantly lower incidence rate of AAD during treatment (χ2=5.77,P

Published
2024
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17. Simultaneously sorting vector vortex beams of 120 modes

Author

Jia, Qi, Zhang, Yanxia, Shi, Bojian, Li, Hang, Li, Xiaoxin, Feng, Rui, Sun, Fangkui, Cao, Yongyin, Wang, Jian, Qiu, Cheng-Wei, and Ding, Weiqiang

Subjects
Physics - Optics
Abstract

Polarization (P), angular index (l), and radius index (p) are three independent degrees of freedom (DoFs) of vector vortex beams, which have been widely used in optical communications, quantum optics, information processing, etc. Although the sorting of one DoF can be achieved efficiently, it is still a great challenge to sort all these DoFs simultaneously in a compact and efficient way. Here, we propose a beam sorter to deal with all these three DoFs simultaneously by using a diffractive deep neural network (D$^2$NN) and experimentally demonstrated the robust sorting of 120 Laguerre-Gaussian (LG) modes using a compact D$^2$NN formed by one spatial light modulator and one mirror only. The proposed beam sorter demonstrates the great potential of D$^2$NN in optical field manipulation and will benefit the diverse applications of vector vortex beams.

Published
2022
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26. Association between Body Mass Index and Clinical Outcomes in Patients with Non-valvular Atrial Fibrillation Receiving Direct Oral Anticoagulants: A New Piece of Evidence on the Obesity Paradox from China

Author

Wu, Shuyi, Huang, Nianxu, Chen, Xia, Jiang, Shaojun, Zhang, Wang, Hu, Wei, Su, Jun, Dai, Hengfen, Gu, Ping, Huang, Xiaohong, Du, Xiaoming, Li, Ruijuan, Zheng, Qiaowei, Lin, Xiangsheng, Zhang, Yanxia, Zou, Lang, Liu, Yuxin, Zhang, Min, Liu, Xiumei, Zhu, Zhu, Sun, Jianjun, Hong, Shanshan, She, Weibin, and Zhang, Jinhua

Published
2023
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28. Vector vortex beams sorting of 120 modes in visible spectrum

Author

Jia Qi, Zhang Yanxia, Shi Bojian, Li Hang, Li Xiaoxin, Feng Rui, Sun Fangkui, Cao Yongyin, Wang Jian, Qiu Cheng-Wei, and Ding Weiqiang

Subjects
vector vortex beam, mode demultiplexing, optical neural network, Physics, QC1-999
Abstract

Polarization (P), angular index (l), and radius index (p) are three independent degrees of freedom (DoFs) of vector vortex beams, which have found extensive applications in various domains. While efficient sorting of a single DoF has been achieved successfully, simultaneous sorting of all these DoFs in a compact and efficient manner remains a challenge. In this study, we propose a beam sorter that simultaneously handles all the three DoFs using a diffractive deep neural network (D2NN), and demonstrate the robust sorting of 120 Laguerre–Gaussian (LG) modes experimentally in the visible spectrum. Our proposed beam sorter underscores the considerable potential of D2NN in optical field manipulation and promises to enhance the diverse applications of vector vortex beams.

Published
2023
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46. Safety and efficacy of direct oral anticoagulants in stroke prevention in patients with atrial fibrillation complicated with anemia and/or thrombocytopenia: a retrospective cohort study

Author

Xu, Wenlin, Chen, Jiana, Wu, Shuyi, Huang, Nianxu, Chen, Xia, Zhang, Wang, Hu, Wei, Su, Jun, Dai, Hengfen, Gu, Ping, Huang, Xiaohong, Du, Xiaoming, Li, Ruijuan, Zheng, Qiaowei, Lin, Xiangsheng, Zhang, Yanxia, Zou, Lang, Liu, Yuxin, Zhang, Min, Liu, Xiumei, Zhu, Zhu, and Zhang, Jinhua

Published
2023
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48. Safety and efficacy of direct oral anticoagulation in patients with and without radiofrequency ablation of non-valvular atrial fibrillation: a multicenter retrospective cohort study

Author

Wu, Shuyi, Guan, Chengfu, Xu, Wenlin, Zhang, Feilong, Huang, Nianxu, Chen, Xia, Zhang, Wang, Hu, Wei, Su, Jun, Dai, Hengfen, Gu, Ping, Huang, Xiaohong, Du, Xiaoming, Li, Ruijuan, Zheng, Qiaowei, Lin, Xiangsheng, Zhang, Yanxia, Zou, Lang, Liu, Yuxin, Zhang, Min, Liu, Xiumei, Zhu, Zhu, Sun, Jianjun, Hong, Shanshan, She, Weibin, and Zhang, Jinhua

Published
2023
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