Massive MIMO Channel Estimation Algorithm Based on Weighted Compressed Sensing

Zhiguo Lv,Weijing Wang 한국정보처리학회 2021 Journal of information processing systems Vol.17 No.6

Compressed sensing-based matching pursuit algorithms can estimate the sparse channel of massive multiple input multiple-output systems with short pilot sequences. Although they have the advantages of low computational complexity and low pilot overhead, their accuracy remains insufficient. Simply multiplying the weight value and the estimated channel obtained in different iterations can only improve the accuracy of channel estimation under conditions of low signal-to-noise ratio (SNR), whereas it degrades accuracy under conditions of high SNR. To address this issue, an improved weighted matching pursuit algorithm is proposed, which obtains a suitable weight value uop by training the channel data. The step of the weight value increasing with successive iterations is calculated according to the sparsity of the channel and uop. Adjusting the weight value adaptively over the iterations can further improve the accuracy of estimation. The results of simulationsconducted to evaluate the proposed algorithm show that it exhibits improved performance in terms of accuracy compared to previous methods under conditions of both high and low SNR.

Schisantherin A Improves Learning and Memory of Mice with D-Galactose-Induced Learning and Memory Impairment Through Its Antioxidation and Regulation of p19/p53/p21/ Cyclin D1/CDK4/RB Gene Expressions

Cong Liu,Weijing Sun,Ning Li,Jiaqi Gao,Chunyan Yu,Chunmei Wang,Jinghui Sun,Shu Jing,JianGuang Chen,He Li 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.7

Schisantherin A (SCA) was evaluated for possible function in restoring the learning and memory impairment induced by D-galactose in mice. ICR mice were treated with D-galactose subcutaneously (220 mg·kg−1), and followed by SCA in different doses (1.25, 2.50 and 5.00 mg·kg−1, administered orally) for 42 days. Effects of SCA on learning and memory were examined by step-through tests and Morris water maze tests. The activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) in the peripheral blood and hippocampus of mice were assayed by water-soluble tetrazolium-1 (WST-1) and thiobarbituric acid (TBA) methods. The contents of 8 hydroxy deoxy guanosine (8-OHdG) in the hippocampus of mice were detected by immunosorbent assay methods, respectively. Quantitative real-time PCR and Western Blot were respectively used to detect the expression of p19, p53, p21, cyclin D1, CDK4 and RB genes, and the phosphorylation of RB in the hippocampus of mice. We found that SCA significantly improved the learning and memory impairment induced by D-galactose in mice. After SCA treatment, SOD activity was increased and the content of MDA was decreased in both peripheral blood and hippocampus of mice. 8-OHDG content was also decreased in the hippocampus of mice. Furthermore, the expression of p19, p53 and p21 genes was reduced and the expression of cyclin D1 and CDK4 and the phosphorylation of RB protein were elevated in the hippocampus. SCA may improve the learning and memory impairment induced by D-galactose by enhancing the antioxidant capacity, and regulating the expression of p19/p53/p21/cyclinD1/CDK4 genes, and the phosphorylation of RB protein in the hippocampus of mice.

Convolutional Neural Network with Expert Knowledge for Hyperspectral Remote Sensing Imagery Classification

( Chunming Wu ),( Meng Wang ),( Lang Gao ),( Weijing Song ),( Tian Tian ),( Kim-kwang Raymond Choo ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.8

The recent interest in artificial intelligence and machine learning has partly contributed to an interest in the use of such approaches for hyperspectral remote sensing (HRS) imagery classification, as evidenced by the increasing number of deep framework with deep convolutional neural networks (CNN) structures proposed in the literature. In these approaches, the assumption of obtaining high quality deep features by using CNN is not always easy and efficient because of the complex data distribution and the limited sample size. In this paper, conventional handcrafted learning-based multi features based on expert knowledge are introduced as the input of a special designed CNN to improve the pixel description and classification performance of HRS imagery. The introduction of these handcrafted features can reduce the complexity of the original HRS data and reduce the sample requirements by eliminating redundant information and improving the starting point of deep feature training. It also provides some concise and effective features that are not readily available from direct training with CNN. Evaluations using three public HRS datasets demonstrate the utility of our proposed method in HRS classification.

Porous Nano-Ni/Graphene/Loofah Composites for Electromagnetic Interference Shielding

Yi Jiang,Mingwei Liang,Weijing Wang,Xuefei Lai,Kenan Xie,Li Liao,Qin Long 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.4

The urgent requirement of materials with superior electromagnetic shielding properties has been aroused for alleviating electromagnetic pollution. Now, some natural materials such as silkworm cocoon, walnut shell, and so on are gradually used to prepare the electromagnetic interference shielding composites. However, loofah sponges with unique and inherent 3D hierarchical porous structure, which could be obtained from food waste and the wilted loofah, are ignored. In this work, loofah sponges were modified by NaOH and H2 O2 . Then the carbonized modified Loofah/Ni nanoparticles/Graphene composites were prepared by immersion and thermal reduction. Meanwhile, the composites had inherited advantages from natural materials such as low density, porous structure and eco-friendly. As the result of loading of Ni nanoparticles and graphene on the loofah, the outstanding performance was achieved that the shielding effectiveness was raised to 57 dB, and the specific shielding effectiveness was raised to 616.8 dB cm 3 /g. This result demonstrated that composites materials based on natural loofah sponges show tremendous potential for electromagnetic shielding.

Research on the method for producing complex SiCP/Al composite disk brake castings

Han Jianmin,Sha Zhensong,Li Weijing,Cui Shihai,Wang Jinhua 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.4

The casting properties of a SiCP/Al composite are analyzed in this paper and the methods for producing complex castings of SiCP/Al composite disk brake together with their difficulty are discussed. An adjustable vacuum pressure casting method is established on the basis of a normal adjustable pressure casting method. The SiCP/Al composite disk brake casting is made with the established method. The results show that the adjustable vacuum pressure casting is a successful casting method for producing SiCP/Al composite castings of large dimensions and complex structures, which gives few defects as confirmed by Xray real- time image system. The casting properties of a SiCP/Al composite are analyzed in this paper and the methods for producing complex castings of SiCP/Al composite disk brake together with their difficulty are discussed. An adjustable vacuum pressure casting method is established on the basis of a normal adjustable pressure casting method. The SiCP/Al composite disk brake casting is made with the established method. The results show that the adjustable vacuum pressure casting is a successful casting method for producing SiCP/Al composite castings of large dimensions and complex structures, which gives few defects as confirmed by Xray real- time image system.

Famine exposure in early life and type 2 diabetes in adulthood: findings from prospective studies in China

Ning Feng,Zhao Jing,Zhang Lei,Wang Weijing,Sun Xiaohui,Song Xin,Zhang Yanlei,Xin Hualei,Gao Weiguo,Gao Ruqin,Zhang Dongfeng,Pang Zengchang 한국영양학회 2023 Nutrition Research and Practice Vol.17 No.4

BACKGROUND/OBJECTIVES: This study examined the relationship between famine exposure in early life and the risk of type 2 diabetes in adulthood during the 1959–1961 Chinese Famine. SUBJECTS/METHODS: A total of 3,418 individuals aged 35–74 years free of diabetes from two studies in 2006 and 2009 were followed up prospectively in 2009 and 2012, respectively. Famine exposure was classified as unexposed (individuals born in 1962–1978), fetal exposed (individuals born in 1959–1961), child exposed (individuals born in 1949–1958), and adolescent/adult exposed (born in 1931–1948). A logistic regression model was used to assess the relationship between famine exposure and diabetes after adjustment for potential covariates. RESULTS: During a three-year follow-up, the age-adjusted incidence rates of type 2 diabetes were 5.7%, 14.5%, 12.7%, and 17.8% in unexposed, fetal-exposed, child-exposed, and adolescent/adult-exposed groups, respectively (P < 0.01). Relative to the unexposed group, the relative risks (95% confidence inter val) for diabetes were 2.15 (1.29–3.60), 1.53 (0.93– 2.51), and 1.65 (0.75–3.63) in the fetal-exposed, child-exposed, and adolescent/adult-exposed groups, after controlling for potential covariates. The interactions between famine exposure and obesity, education level, and family histor y of diabetes were not obser ved, except for the urbanization type. Individuals living in rural areas with fetal and childhood famine exposure were at a higher risk of type 2 diabetes, with relative risks of 8.79 (1.82–42.54) and 2.33 (1.17–4.65), respectively. CONCLUSIONS: These findings indicate that famine exposure in early life is an independent predictor of type 2 diabetes, particularly in women. Early identification and inter vention may help prevent diabetes in later life.