Joint Resource Allocation for Cellular and D2D Multicast Based on Cognitive Radio

( Xiaolu Wu ),( Yueyun Chen ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.1

Device-to-device (D2D) communication is an excellent technology to improve the system capacity by sharing the spectrum resources of cellular networks. Multicast service is considered as an effective transmission mode for the future mobile social contact services. Therefore, multicast based on D2D technology can exactly improve the spectrum resource efficiency. How to apply D2D technology to support multicast service is a new issue. In this paper, a resource allocation scheme based on cognitive radio (CR) for D2D underlay multicast communication (CR-DUM) is proposed to improve system performance. In the cognitive cellular system, the D2D users as secondary users employing multicast service form a group and reuse the cellular resources to accomplish a multicast transmission. The proposed scheme includes two steps. First, a channel allocation rule aiming to reduce the interference from cellular networks to receivers in D2D multicast group is proposed. Next, to maximize the total system throughput under the condition of interference and noise impairment, we formulate an optimal transmission power allocation jointly for the cellular and D2D multicast communications. Based on the channel allocation, optimal power solution is in a closed form and achieved by searching from a finite set and the interference between cellular and D2D multicast communication is coordinated. The simulation results show that the proposed method can not only ensure the quality of services (QoS), but also improve the system throughput.

Effect of Ga alloying on thermoelectric properties of InSb

Zhengliang Du,Xiaolu Chen,Junhao Zhu,Jiaolin Cui 한국물리학회 2018 Current Applied Physics Vol.18 No.8

As a potential thermoelectric (TE) material, the high lattice thermal conductivity and relatively low weighted mobility severely limit TE property optimization of InSb binary compound. In this paper, we substituted In of InSb with Ga and systematically investigated the effect of Ga alloying on the Seebeck coefficient, electrical conductivity and lattice thermal conductivity of InSb between 300 K and 770 K. We found that Ga alloying simultaneously reduced the lattice thermal conductivity and optimized the weighted mobility of InSb. The lattice thermal conductivity has been analyzed using Abeles model to gain more insight on the roles of Ga in In1-xGaxSb (x=0, 0.1, 0.15, 0.2) solid solution. The synergetic effect of Ga alloying on the electron and phonon transport leads to a marked enhancement in TE potential of InSb. The dimensionless figures of merit of InSb and In0.8Ga0.2Sb reach, respectively, 0.54 and 0.52 at 770 K.

Design and Positioning Control of a Flexure-Based Nano-positioning Stage Driven by Halbach Array Voice Coil Actuator

Chi Zhang,Xiaolu Huang,Miao Yang,Si-Lu Chen,Jinhua Chen,Guilin Yang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.3

A long-stroke nano-positioning stage driven by voice coil actuator (VCA) and supported by flexure guide is designed in this paper. The Halbach permanent magnet array is implemented in the VCA to improve the air-gap flux density with the magnetic concentration effect. The air-gap magnetic fi eld is modeled with an equivalent magnetic structure and verified by finite element analysis. The proposed equivalent magnetic structure reduces the number of boundary condition equations and hence simplifies the analysis procedure. Besides, a novel spring-damping tuning method is proposed based on the equivalent dynamic model of the closed-loop system. This tuning method regards P control and D control as a virtual spring and a virtual damper. The controller parameters are tuned in an intuitive way. Experimental results show that the positioning stage is capable of achieving a resolution of 40 nm within a stroke of 0.8 mm with high repeatability. The spring-damping tuning method ensures better control performance compared to Ziegler Nichols (Z–N) tuning method where overshoot and settling time are decreased.

Electroacupuncture-Modulated MiR106b-5p Expression Enhances Autophagy by Targeting Beclin-1 to Promote Motor Function Recovery After Spinal Cord Injury in Rats

Shuhui Guo,Jianmin Chen,Ye Yang,Xiaolu Li,Yun Tang,Yuchang Gui,Jianquan Chen,Jianwen Xu 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: Electroacupuncture (EA) has a definite effect on the treatment of spinal cord injuries (SCIs), but its underlying molecular mechanism remains unclear. Meanwhile, MiR-106b-5p is an autophagy- and apoptosis-related microribonucleic acid, but whether it regulates the progression of autophagy and apoptosis in SCIs is yet undetermined. As such, this study aimed to elucidate the involvement of miR-106b-5p in the EA treatment of an SCI. Methods: The miR-106b-5p level was detected by quantitative real-time polymerase chain reaction. In vitro, SH-SY5Y cells were transfected with miR-106b-5p mimics or inhibitors to regulate the miR-106b-5p expression, while in vivo, SCI rats were treated with EA for 7 days at the bilateral Zusanli (ST36) and Jiaji (EX-B2) acupoints. The motor function was evaluated using the Basso-Beattie-Bresnahan (BBB) criteria. Further, autophagic vacuoles, pathological damage, and neuronal cell morphology were observed by transmission electron microscopy, as well as by hematoxylin and eosin and Nissl staining, respectively. Results: The miR-106b-5p level, which can interact directly with Beclin-1 by influencing its expression, as well as the expressions of P62, Caspase-3, and Bax, was upregulated after an SCI, but it decreased after EA. Moreover, the ratio of LC3-II to LC3-I was upregulated after EA. EA can enhance autophagy, reduce neuronal apoptosis, and minimize motor dysfunction and histopathological deficits after an SCI. More importantly, however, all the above effects induced by EA can be reversed after an injection of miR-106-5p agomir to produce an overexpression of miR-106b-5p. Conclusion: EA treatment could downregulate miR-106b-5p to alleviate SCI-mediated injuries by promoting autophagy and inhibiting apoptosis.

Risk Assessment of Power System Security based on a Hybrid Optimization GP Method

Xiaobin Wu,Hui Li,Xiaolu Chen 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.12

In this paper, we propose a hybrid optimization algorithm based on Improved Differential Evolution (IDE) algorithm and Gaussian Process (GP). Firstly, the paper constructs the assessment index system using Fault Tree Analysis (FTA) based on the summary and classification of the factors that could affect the power system security. Secondly, establish the risk assessment model of power system security based on the hybrid optimization GP algorithm. Hyper-parameter of GP has a great influence on construction of evaluation model, while conjugate gradient method which is usually used has strong dependence on initial values and is easy to fall into local optimal solution. So the paper uses the IDE algorithm for the traditional Hyper-parameter optimization, then the optimal Hyper-parameter is used to construct evaluation model for power grid security risk assessment. In the process of improvement, this paper adds the local search (Bees accelerated evolution operation) and global search (Bees scout operation) thought of ABC algorithm into the DE algorithm to reduce the population size required by the algorithm. After that, do the risk assessment of power system by using the established assessment model. Finally, do the simulation experiments using the standard data IEEE-39 and IEEE-118 bus example, and besides compare the IDE-GP with other optimization model like ABC-GP, DE-GP, MA-GP, GA-GP, and the experimental results show that hybrid optimization algorithm has better performance in accuracy while the time-consuming difference is minor. The validity of the proposed method is also demonstrated.

Deep convolutional neural network: a novel approach for the detection of Aspergillus fungi via stereomicroscopy

Ma Haozhong,Yang Jinshan,Chen Xiaolu,Jiang Xinyu,Su Yimin,Qiao Shanlei,Zhong Guowei 한국미생물학회 2021 The journal of microbiology Vol.59 No.6

Fungi of the genus Aspergillus are ubiquitously distributed in nature, and some cause invasive aspergillosis (IA) infections in immunosuppressed individuals and contamination in agricultural products. Because microscopic observation and molecular detection of Aspergillus species represent the most operator-dependent and time-intensive activities, automated and cost-effective approaches are needed. To address this challenge, a deep convolutional neural network (CNN) was used to investigate the ability to classify various Aspergillus species. Using a dissecting microscopy (DM)/stereomicroscopy platform, colonies on plates were scanned with a 35× objective, generating images of sufficient resolution for classification. A total of 8,995 original colony images from seven Aspergillus species cultured in enrichment medium were gathered and autocut to generate 17,142 image crops as training and test datasets containing the typical representative morphology of conidiophores or colonies of each strain. Encouragingly, the Xception model exhibited a classification accuracy of 99.8% on the training image set. After training, our CNN model achieved a classification accuracy of 99.7% on the test image set. Based on the Xception performance during training and testing, this classification algorithm was further applied to recognize and validate a new set of raw images of these strains, showing a detection accuracy of 98.2%. Thus, our study demonstrated a novel concept for an artificial-intelligence-based and cost-effective detection methodology for Aspergillus organisms, which also has the potential to improve the public’s understanding of the fungal kingdom.

Study on Spinnability of PP/PU Blends and Preparation of PP/PU Bi-component Melt Blown Nonwovens

Yanfen Zhou,Liang Jiang,Huiying Jia,Xiaolu Xing,Zhenhua Sun,Shaojuan Chen,Jianwei Ma,Stephen Jerrams 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

Melt blown polymer blends offers a good way to combine two polymers in the same fiber generating nonwovenswith new and novel properties. In this study, polypropylene (PP) and polyurethane (PU) were blended to prepare PP/PU bicomponentmelt blown nonwovens. The spinnability of PP/PU composites was investigated and PP/PU bi-componentnonwovens with compositions of 95/5, 90/10, 80/20 and 70/30 were prepared by using the melt blowing technique. The meltblown fibers exhibited a ‘sea-island’ structure with PP as the continuous phase and PU as the dispersed phase. When thecontent of PU in the blend was above 40 %, PP/PU melt blown nonwovens could not be produced due to fiber breaking. ForPP/PU (90/10) nonwovens, it was found that the average fiber diameter decreased with increasing die to collector (DCD) andelevated hot air pressure.

Microwave-assisted pyrolysis of phosphoric acid-activated Goldenberry peel powder biochar for enhancing the adsorption of trace beta-lactamase inhibitors

Tian Ai,Chunmei Xu,Lei Zhang,Ke Chen,Yonggui Wu,Shujuan Dai,Xiaolu Xiong,Shixin Jie,Xiaoni Jin,Zhongxu Yu 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.9

Novel efficient biochar of Goldenberry peels (GBPMW-H3PO4) was prepared through a microwave-assistedphosphoric acid activation method. It was characterized and used for removing two beta-lactamase inhibitors, sulbactam(SAM, first listed in Japan in 1986) and avibactam (AVI, first listed in the U.S. in 2015), from aqueous solution. Characterization confirmed that GBPMW-H3PO4 displayed a high surface area (720.046m2 g1), more abundant porestructure, smaller particle size, and higher thermal stability. The experimental results showed that the adsorption of thetwo antibiotics was a spontaneous, favorable, and endothermic process, highly dependent on solution pH. A contacttime of 60 min assured equilibrium, and GBPMW-H3PO4 followed pseudo-first-order kinetics (R2=0.9950-0.9977). Furthermore,the adsorption capacities of GBPMW-H3PO4 for SAM and AVI were 211.86 and 198.81mg g1, respectively,and the performance was better than that of unmodified biochar. Microscopically, the main mechanism could beexplained by - electron donor-acceptor interaction, hydrogen bonding interaction, -hydrogen bonding, hydrophobicinteraction, and electrostatic interaction. The study demonstrates that the microwave-assisted H3PO4 activationmethod could produce biochar, and GBPMW-H3PO4 was confirmed to be a low-cost and high-efficiency adsorbent forremoving beta-lactamase inhibitors from medical wastewater.