A Novel Cooperative Spectrum Sensing Algorithm in Cognitive Radio Systems

Xueqiang Zheng,Jinlong Wang,Qihui Wu,Liang Shen 한국통신학회 2009 Journal of communications and networks Vol.11 No.2

In cognitive radio (CR) systems, cognitive users can use the frequency bands when the primary users are not present. Hence, reliable detection of available spectrum is foundation of cognitive radio technology. To ensure unimpaired operation of primary users, cooperative spectrum sensing is needed. To reduce the network overhead of cooperative spectrum sensing, a novel cooperative spectrum sensing algorithm based on credibility is proposed. In particular, the close-form expressions for probability of detection and false-alarm are derived for the novel algorithm, and expression for the average overhead used for cooperation is given. The thresholds design method for the algorithm is also discussed. The conclusion is proved by computer simulations.

Bone Morphogenetic Protein Receptor in the Osteogenic Differentiation of Rat Bone Marrow Stromal Cells

Anxun Wang,Xueqiang Ding,Shihu Sheng,Zhaoyou Yao 연세대학교의과대학 2010 Yonsei medical journal Vol.51 No.5

Purpose: Several signaling pathways have been shown to regulate the lineage commitment and terminal differentiation of bone marrow stromal cells (BMSCs). Bone morphogenetic protein (BMP) signaling has important effects on the process of skeletogenesis. In the present study, we tested the role of bone morphogenetic protein receptor (BMPR) in the osteogenic differentiation of rat bone marrow stromal cells in osteogenic medium (OM) with or without BMP-2. Materials and Methods: BMSCs were harvested from rats and cultured in OM containing dexamethasone,β-glycerophosphate, and ascorbic acid, with or without BMP-2 in order to induce osteogenic differentiation. The alkaline phosphatase (ALP) activity assay and von kossa staining were used to assess the osteogenic differentiation of the BMSCs. BMPR mRNA expression was assessed using reverse transcriptionpolymerase chain reaction (RT-PCR). Results: The BMSCs that underwent osteogenic differentiation in OM showed a higher level of ALP activity and matrix mineralization. BMP-2 alone induced a low level of ALP activity and matrix mineralization in BMSCs, but enhanced the osteogenic differentiation of BMSCs when combined with OM. The OM significantly induced the expression of type IA receptor of BMPR (BMPRIA) and type II receptor of BMPR (BMPRII) in BMSCs after three days of stimulation, while BMP-2 significantly induced BMPRIA and BMPRII in BMSCs after nine or six days of stimulation, respectively. Conclusion: BMSCs commit to osteoblastic differentiation in OM, which is enhanced by BMP-2. In addition, BMP signaling through BMPRIA and BMPRII regulates the osteogenic differentiation of rat BMSCs in OM with or without BMP-2.

A Novel Cooperative Spectrum Sensing Algorithm in Cognitive Radio Systems

Zheng, Xueqiang,Wang, Jinlong,Wu, Qihui,Shen, Liang The Korea Institute of Information and Commucation 2009 Journal of communications and networks Vol.11 No.2

In cognitive radio (CR) systems, cognitive users can use the frequency bands when the primary users are not present. Hence, reliable detection of available spectrum is foundation of cognitive radio technology. To ensure unimpaired operation of primary users, cooperative spectrum sensing is needed. To reduce the network overhead of cooperative spectrum sensing, a novel cooperative spectrum sensing algorithm based on credibility is proposed. In particular, the close-form expressions for probability of detection and false-alarm are derived for the novel algorithm, and expression for the average overhead used for cooperation is given. The thresholds design method for the algorithm is also discussed. The conclusion is proved by computer simulations.

The Role of Macrophage Migration Inhibitory Factor (MIF) in Asthmatic Airway Remodeling

Li Ruyi,Wang Feiyun,Wei Jianghong,Lin Yun,Tang Guofang,Rao Lizong,Ma Libing,Xu Qing,Wu Jingjie,Lv Qian,Zhou Rui,Lei Huiren,Zhao Xueqiang,Yao Dong,Xiao Bo,Huang Haiming,Zhang Jiange,Mo Biwen 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.1

Purpose: Recent studies have demonstrated that macrophage migration inhibitory factor (MIF) is of importance in asthmatic inflammation. The role of MIF in modulating airway remodeling has not yet been thoroughly elucidated to date. In the present study, we hypothesized that MIF promoted airway remodeling by intensifying airway smooth muscle cell (ASMC) autophagy and explored the specific mechanisms. Methods: MIF knockdown in the lung tissues of C57BL/6 mice was conducted by instilling intratracheally adeno-associated virus (AAV) vectors (MIF-mutant AAV9) into mouse lung tissues. Mice genetically deficient in the autophagy marker ATG5 (ATG5+/−) was used to detect the role of autophagy in ovalbumin (OVA)-asthmatic murine models. Moreover, to block the expression of MIF and CD74 in vitro models, inhibitors, antibodies and lentivirus transfection techniques were employed. Results: First, MIF knockdown in the lung tissues of mice showed markedly reduced airway remodeling in OVA murine mice models. Secondly, ASMC autophagy was increased in the OVA-challenged models. Mice genetically deficient in the autophagy marker ATG5 (ATG5+/−) that were primed and challenged with OVA showed lower airway remodeling than genetically wild-type asthmatic mice. Thirdly, MIF can induce ASMC autophagy in vitro. Moreover, the cellular source of MIF which promoted ASMC autophagy was macrophages. Finally, MIF promoted ASMC autophagy in a CD74-dependent manner. Conclusions: MIF can increase asthmatic airway remodeling by enhancing ASMC autophagy. Macrophage-derived MIF can promote ASMC autophagy by targeting CD74.

Outage Analysis of CRNs with SC Diversity Over Nakagami-m Fading Environment

( Zongsheng Zhang ),( Qihui Wu ),( Xueqiang Zheng ),( Jinlong Wang ),( Lianbao Li ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.12

In this paper, we investigate the outage performance of a cognitive relay network. We consider mutual interference in an independent, non-identically distributed Nakagmai-m fading environment. We first derive the close-form outage probability expression, which provides an efficient means to evaluate the effects of several parameters. This allows us to study the impact of several parameters on the network`s performance. We then derive the asymptotic expression and reveal that the diversity order is strictly determined by the fading severity of the cognitive system. It is not affected by the primary network. Moreover, the primary network only affects the coding gain of the cognitive system. Finally, Monte Carlo simulations are provided, which corroborate the analytical results.

MRU-Net: A remote sensing image segmentation network for enhanced edge contour Detection

Jing Han,Weiyu Wang,Yuqi Lin,Xueqiang LYU 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.12

Remote sensing image segmentation plays an important role in realizing intelligent city construction. The current mainstream segmentation networks effectively improve the segmentation effect of remote sensing images by deeply mining the rich texture and semantic features of images. But there are still some problems such as rough results of small target region segmentation and poor edge contour segmentation. To overcome these three challenges, we propose an improved semantic segmentation model, referred to as MRU-Net, which adopts the U-Net architecture as its backbone. Firstly, the convolutional layer is replaced by BasicBlock structure in U-Net network to extract features, then the activation function is replaced to reduce the computational load of model in the network. Secondly, a hybrid multi-scale recognition module is added in the encoder to improve the accuracy of image segmentation of small targets and edge parts. Finally, test on Massachusetts Buildings Dataset and WHU Dataset the experimental results show that compared with the original network the ACC、mIoU and F1 value are improved, and the imposed network shows good robustness and portability in different datasets.

Removal and fate of carbamazepine in the microbial fuel cell coupled constructed wetland system

Jingyi Xie,Haixiao Li,Shiyu Wang,Hao Chen,Wei Jiang,Lin Zhang,Lianjie Wang,Yufeng Wu,Lirong Li,Xueqiang Lu 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.3

Carbamazepine (CBZ), which is difficult to remove in the wastewater treatment system and easily forms toxic transformation products during the treatment process, is one of the priority pollutants of pharmaceuticals and personal care products (PPCPs). Increasing attention has been paid to explore their treatment technology without side effects from the treatment products. This study aims to reveal the removal and transformation of CBZ in the microbial fuel cell coupled constructed wetland (CW-MFC) system. The CW-MFC system was operated continuously at room temperature for nearly 80 days. The results show that CW-MFC system can effectively remove CBZ with an average removal rate of 97%. Three transformation products were identified by liquid chromatography−high-resolution mass spectrometry: 2-(2-oxoquinazolin-1(2H)-yl) benzoic acid (TP267), methyl 2-(2-oxoquinazolin-1(2H)-yl) benzoate (TP281), 2-(2,4-dioxo-3,4-dihydroquinazolin-1(2H)-yl) benzoic acid (TP283). Except TP281 in the influent, the other transformation products were formed in the system, which indicated that TP267 and TP283 were the main transformation products of CBZ. The formation pathway of transformation products could be explained by reactions including oxidation, hydrolysis, bond rupture and intramolecular reaction. The results also indicate that the CW-MFC system might be a promising technology for PPCPs treatment.

Identifying natural genotypes of grain number per panicle in rice (Oryza sativa L.) by association mapping

Jianyin Xie,Fengmei Li,Najeeb Ullah Khan,Xiaoyang Zhu,Xueqiang Wang,Zhifang Zhang,Xiaoqian Ma,Yan Zhao,Quan Zhang,Shuyang Zhang,Zhanying Zhang,Jinjie Li,Zichao Li,Hongliang Zhang 한국유전학회 2019 Genes & Genomics Vol.41 No.3

Introduction As one of the main yield components, grain number per panicle (GNP) played critical role in the rice yield improvement. The identification of natural advantageous variations under different situations will promote the sustainable genetic improvement in rice yield. Objectives This study was designed to identify natural genotypes in a rice mini-core collection, to examine the genotypic effects across the indica and japonica genetic background in different environments, and excavating the superior genotypes that had drove the modern genetic improvement. Methods The association mapping of GNP was carried out using a mini-core collection including 154 indica and 119 japonica accessions in seven different environments. Genotypic effects of each genotype for each QTL were calculated and genotype frequency distortion between the commercial rice cultivars and landraces was screened by χ2-test. Results In total, 74 QTLs containing stable and sensitive QTLs in various environments were detected. Within them, 20 positive and 24 negative genotypes in indica, and 24 positive and 16 negative genotypes in japonica were identified. When checking the accumulation of positive genotypes identified in indica across cultivars in each of the two subspecies, it indicated that increased number of positive genotypes identified in indica results in the substantially increased GNP in both indica and japonica across all of the environments, while this trend was not obvious for the positive genotypes identified in japonica especially in short day environments. Moreover, the positive and negative genotype frequency distortion between the landraces and commercial rice cultivars indicated that both positive selection of positive genotypes and negative selection of negative genotypes had driven the genetic improvement on GNP. Conclusion Our findings suggested that the accumulation of positive genotypes and purifying negative genotypes played equivalently important roles in the improvement of rice yield, but the efficient use for some QTLs or genotypes depends on the comprehensive evaluation of their effect under diverse genetic backgrounds and environments.