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Improving Channel Estimation in a NOMA Modulation Environment Based on Ensemble Learning

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1315-1337页

作者： Lassaad K.Smirani Leila Jamel Latifah Almuqren Elearning Deanship and Distance Education Umm Al-Qura UniversityP.O.Box 715MekkahSaudi Arabia Department of Information Systems College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia

This study presents a layered generalization ensemble model for next generation radio mobiles,focusing on supervised channel estimation *** estimation typically involves the insertion of pilot symbols with a well-balanced rhythm and suitable *** model,called Stacked Generalization for Channel Estimation(SGCE),aims to enhance channel estimation performance by eliminating pilot insertion and improving *** SGCE model incorporates six machine learning methods:random forest(RF),gradient boosting machine(GB),light gradient boosting machine(LGBM),support vector regression(SVR),extremely randomized tree(ERT),and extreme gradient boosting(XGB).By generating meta-data from five models(RF,GB,LGBM,SVR,and ERT),we ensure accurate channel coefficient predictions using the XGB *** validate themodeling performance,we employ the leave-one-out cross-validation(LOOCV)approach,where each observation serves as the validation set while the remaining observations act as the training *** performances’results demonstrate higher mean andmedian accuracy compared to the *** achieves an average accuracy of 98.4%,precision of 98.1%,and the highest F1-score of 98.5%,accurately predicting channel ***,our proposedmethod outperforms prior traditional and intelligent techniques in terms of throughput and bit error ***’s superior performance highlights its efficacy in optimizing channel *** can effectively predict channel coefficients and contribute to enhancing the overall efficiency of radio mobile *** extensive experimentation and evaluation,we demonstrate that SGCE improved performance in channel estimation,surpassing previous ***,SGCE’s capabilities have significant implications for optimizing channel estimation in modern communication systems.

关键词： Stacked generalization ensemble learning Non-Orthogonal Multiple Access(NOMA) channel estimation 5G

Seasonal characteristics and formation mechanism of the thermohaline structure of mesoscale eddy in the South China Sea

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Acta Oceanologica Sinica 2019年第4期38卷 29-38页

作者： Yongcan Zu Shuangwen Sun Wei Zhao Peiliang Li Baochao Liu Yue Fang Azizan Abu Samah college of Oceanic and Atmospheric Sciences Ocean University of China Center for Ocean and Climate Research First Institute of OceanographyMinistry of Natural Resources Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology (Qingdao) Ocean college Zhejiang University Institute of Ocean and Earth Sciences University of Malaya

The seasonal characteristics and formation mechanism of the thermohaline structure of mesoscale eddy in the South China Sea are investigated using the latest eddy dataset and ARMOR3D data. Eddy-centric composites reveal that the horizontal distribution of temperature anomaly associated with eddy in winter is more of a dipole pattern in upper 50 m and tends to be centrosymmetric below 50 m, while in summer the distribution pattern is centrosymmetric in the entire water column. The horizontal distribution of eddy-induced salinity anomaly exhibits similar seasonal characteristics, except that the asymmetry of the salinity anomaly is weaker. The vertical distribution of temperature anomaly associated with eddy shows a monolayer structure, while the salinity anomaly demonstrates a triple-layer structure. Further analysis indicates that the vertical distribution of the anomalies is related to the vertical structure of background temperature and salinity fields, and the asymmetry of the anomalies in upper 50 m is mainly caused by the horizontal advection of background temperature and salinity.

关键词： mesoscale eddy thermohaline structure seasonal characteristics South China Sea

Study on flow characteristics and phase holdup in a slurry bubble column coupled with mild agitation Author links open overlay panel

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Particuology 2024年第8期91卷 226-234页

作者： Qingyuan An Jiantao Li Lei Zhang Nailiang Wang Pengfei Zhang Zhenghong Luo Chunxi Lu State Key Laboratory of High-Efficiency Coal Utilization and Green Chemical Engineering Ningxia UniversityYinchuan750021China State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and EnvironmentChina University of Petroleum BeijingBeijing102249China Department of Chemical&Biological Engineering Monash UniversityVictoria3800Australia

A pilot-scale experimental setup was constructed to investigate the effect of mild agitation on the bubble characteristics and phase holdup in a slurry bubble *** agitation positively impacts the axial uniform distribution of solid holdup,though it shows insignificant influence on the radial *** homogenous regime,mild agitation promotes the coalescence of bubbles,and the effect becomes stronger with increasing agitator *** mild agitation contributes to a decrease in bubble size in heterogeneous flow *** agitation presents a significant effect on the gas holdup by adjusting the bubble size and bubble motion *** modification was introduced to predict the gas holdup considering the effects of mild agitation,a necessary consideration for applications requiring mild *** adapted model predicts gas holdup with a maximum error of 12.9%.

关键词： Slurry bubble column Mild agitation Phase holdup Bubble characteristics

Hazardous Attitude Factors Influence Risk Perception in General Aviation pilots

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Advances in Aerospace Science and Technology 2024年第3期9卷 85-93页

作者： Athina Holmes Aeronautical Science Department College of Aviation Embry-Riddle Aeronautical University Daytona Beach FL USA

This manuscript presents a research proposal to investigate how hazardous attitudes among general aviation pilots influence pilot performance in aviation accidents. General aviation pilots train to maintain safe flying conditions, but accidents still occur, and human factors figure prominently among the causes of aviation accidents. The levels of hazardous attitudes among pilots may influence the likelihood of engaging in risky flight behaviors that can lead to accidents. This quantitative study aims to determine whether dangerous attitudes impact risk perception in general aviation pilots. The study will focus on two specific hazardous attitudes, “Anti-Authority” and Macho” behaviors. Among the hazardous attitudes identified by the Federal Aviation Administration (FAA), the two attitudes often stand out in accident investigations and pilot narratives. While all hazardous attitudes have inherent dangers, these two attitudes tend to be more frequently cited in accident reports and investigations. Despite rigorous training in safe flying conditions, general aviation accidents still transpire due to human factors. This research hypothesizes that the five attitudes from the hazardous attitude model, particularly Anti-Authority and Macho, significantly shape pilots’ risk perception. The insights from this study would benefit stakeholders, like the Aircraft Owners and pilots Association (AOPA), Air Safety Institute, and aviation training programs, in creating training modules tailored to reduce such attitudes.

关键词： General Aviation (GA) pilot Aviation Safety Hazardous Attitudes Anti-Authority Macho Risk Perception Flight Training

Seasonal variability of the wind-generated near-inertial energy flux in the South China Sea

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Acta Oceanologica Sinica 2019年第4期38卷 136-145页

作者： Baonan Sun Zhan Lian Yeli Yuan Haiyang Xu college of Oceanic and Atmospheric Sciences Ocean University of China Key Laboratory of Marine Science and Numerical Modeling First Institute of OceanographyMinistry of Natural Resources Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology (Qingdao)

After validated by the in-situ observation, the slab model is used to study the wind-generated near-inertial energy flux(NIEF) in the South China Sea(SCS) based on satellite-observed wind data, and its dependence on calculation methods and threshold criteria of the mixed layer depth(MLD) is investigated. Results illustrate that the total amount of NIEF in the SCS could be doubled if different threshold criteria of MLD are adopted. The NIEF calculated by the iteration and spectral solutions can lead to a discrepancy of 2.5 GW(1 GW=1×109 W). Results also indicate that the NIEF exhibits spatial and temporal variations, which are significant in the boreal autumn,and in the southern part of the SCS. Typhoons are an important generator of NIEF in the SCS, which could account for approximately 30% of the annual mean NIEF. In addition, deepening of the MLD due to strong winds could lead to a decrease of NIEF by approximately by 10%. We re-estimate the annual mean NIEF in the SCS,which is(10±4) GW and much larger than those reported in previous studies.

关键词： near-inertial energy flux mixed layer depth South China Sea typhoon

The Island Rule with lateral and bottom friction

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Acta Oceanologica Sinica 2019年第4期38卷 146-153页

作者： Yanzhao Yang Zexun Wei Guanlin Wang Zhan Lian Liwei Wang college of Meteorology and Oceanography National University of Defense Technology college of Mathematical Science and Physics Qingdao University of Science and Technology Key Laboratory of Marine Science and Numerical Modeling First Institute of OceanographyMinistry of Natural Resources Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology (Qingdao)

The Island Rule, derived from the Sverdrup theory, is widely used to estimate and analyze water transport through a strait. Previous studies presented single-or multi-island rules with either lateral or bottom friction. In this paper,an analytical model of wind-driven circulation is assumed based on linear dynamics. Considering both lateral and bottom friction, the analytic solutions of the transport streamfunction around the islands are derived and the volume transport through the channel is presented. The results are similar to those of Wajsowicz, but the frictional constants represent different values. The analytic solution shows that the relationship between the lateral frictional and bottom frictional dissipation is complex in terms of the frictional constants. To understand the interaction between the two friction types, lateral and bottom friction values were randomly chosen on a barotropic beta plane. The result shows an approximately linear relationship between the lateral and bottom friction in consisting of the combined frictional constants. We studied the effect of the channel width on the transport through the channel. The results show that the friction enhances the flow under some widths, which is similar to the flow behavior when only the lateral friction is considered. We also compared the transport through the channel at different depths and founded that the deeper the water, the smaller the transport reduction ratio when the horizontal eddy viscosity coefficient and the bottom drag coefficient remained constants. To further present the combined role of lateral frictional and bottom frictional dissipation, we compared our model with the model of Wajsowicz for two islands, where only the lateral or bottom friction were considered, with different channel widths. The results showed that the effect of the lateral friction is greater than the bottom friction when the channel is narrow, especially in the Munk boundary layer thickness. When the channel is

关键词： Island Rule lateral friction bottom friction transport streamfunction

Dietary Supplementation with Sea Cucumber Saponins and Exercise Can Significantly Suppress Adipose Accumulation in Mice Fed with High-Fat Diet

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Journal of Ocean University of China 2021年第3期20卷 629-640页

作者： LI Rong MENG Jing SHI Haohao WANG Chengcheng LI Zhaojie XUE Changhu WANG Yuming ZHANG Tiantian college of Food Science and Engineering Ocean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Jining Center for Food and Drug Control Jining 272025China

Dietary supplementation with sea cucumber saponins(SCS)and exercise have been confirmed to be effective in pre-venting the development of obesity and its related ***,the combined effectiveness of these interventions has not been ***,we studied whether the beneficial influences of exercise could be further enhanced by dietary supplementation with SCS in high-fat diet-fed KM(Kunming)*** were randomly divided into four groups,including the high-fat diet group(HF),the SCS group(HF-S),the exercise group(HF-E),and the combination of dietary SCS and exercise group(HF-S+E).There were eight mice in every *** results demonstrated that the combination of dietary SCS and exercise could synergistically reduce fat *** particular,white adipose tissue decreased by 63%in the HF-S+E group compared with that in the HF *** supplementation with exercise also improved peripheral markers,such as serum parameters and hepatic TG *** mechani-cal testing indicated that the combined effects of dietary SCS and exercise on inhibiting fat accumulation might be attributed to the inhibition of lipid synthesis in the liver and the activation of lipolysis in white adipose tissue to increase energy consumption.

关键词： exercise sea cucumber saponins fat accumulation lipogenesis lipolysis

Teleseismic P-Wave Tomography of the New Guinea-Solomon Arc System

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Journal of Ocean University of China 2022年第3期21卷 694-706页

作者： FENG Bing ZHANG Hao GONG Wei XING Junhui LI Deyong XU Chong AN Long Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of Educationand College of Marine GeosciencesOcean University of ChinaQingdao266100China Laboratory for Marine Mineral Resources Pilot National Laboratory Qingdao for Marine Science and Technology(Qingdao)Qingdao266237China

A P-wave tomographic traveltime inversion was applied to obtain a new model of seismic velocity anomalies beneath the New Guinea-Solomon arc system(PN-SL).The P-wave traveltime data,obtained from the revised International Seismological Center catalog,were recorded by 82 seismic stations in the *** the constraints of the epicenter distance,magnitude,and the number of stations recorded,15009 effective P-wave traveltime data were selected from 2011 teleseismic *** obtained model showed that the Solomon Sea Plate subducted beneath the New Britain Island along the New Britain Trench at an angle of>70°and that the slab can be traced down to a depth of approximately 800 ***,we cannot observe a high-velocity anomaly exhibited by the subducted Solomon Sea Plate in the deep mantle at the Trobriand Trench,and the slab stopped at a depth of<200 *** double subduction of the Solomon Sea Plate strongly modified the subduction patterns of the early subducted Pacific and Australian plates in the mantle along the West Melanesian Trench and the Pocklington Trough,*** addition,the subducted Solomon Sea Plate induced the melting of the upper mantle to form a low-velocity anomaly,which provided the deep dynamic source for the expansion of the Bismarck *** on the joint consideration of the tomography results and a petrological analysis,the low-velocity anomalies beneath the Solomon Sea and Woodlark Basin are closely related to the early subduction of the Pacific and Australian Plates,respectively.

关键词： New Guinea-Solomon arc system traveltime tomography trench back-arc basin

A new type of internal solitary waves with a re-appearance period of 23 h observed in the South China Sea

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Acta Oceanologica Sinica 2018年第9期37卷 116-118页

作者： CHEN Liang ZHENG Quanan XIONG Xuejun YUAN Yeli XIE Huarong college of Oceanic and Atmospheric Sciences Ocean University of China The First Institute of Oceanography State Oceanic Administration Functional Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology (Qingdao) Department of Atmospheric and Oceanic Science University of MarylandCollege Park

The South China Sea （SCS）, in particular the northern SCS, is one of ocean areas where energetic internal solitary waves （ISWs）occur most frequently （Cai et al., 2012; Zheng, 2017）. Based on the re-appearance period （RP） at an observation station, Ramp et al.（2004） divided the ISWs into two types：Type-a and Type-b. Type-a ISWs arrive regularly at the same time every day, i.e., the RP is about 24 h, and Type-b ISWs arrive about one hour late every day, i.e., the RP is about 25 h.

关键词： SCS A new type of internal solitary waves with a re-appearance period of 23 h observed in the South China Sea