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Underwater Pulse Waveform Recognition Based on Hash Aggregate Discriminant Network

Journal of ocean University of China 2024年第3期23卷 654-660页

作者： WANG Fangchen ZHONG Guoqiang WANG Liang college of Computer Science and Technology Ocean University of ChinaQingdao 266100China college of Marine Technology Ocean University of ChinaQingdao 266100China

Underwater pulse waveform recognition is an important method for underwater object *** existing works focus on the application of traditional pattern recognition methods,which ignore the time-and space-varying characteristics in sound propagation channels and cannot easily extract valuable waveform *** propagation channels in seawater are time-and space-varying convolutional *** the extraction of the waveform features of underwater acoustic signals,the effect of high-accuracy underwater acoustic signal recognition is identified by eliminating the influence of time-and space-varying convolutional channels to the greatest extent *** propose a hash aggregate discriminative network(HADN),which combines hash learning and deep learning to minimize the time-and space-varying effects on convolutional channels and adaptively learns effective underwater waveform features to achieve high-accuracy underwater pulse waveform *** the extraction of the hash features of acoustic signals,a discrete constraint between clusters within a hash feature class is *** constraint can ensure that the influence of convolutional channels on hash features is *** addition,we design a new loss function called aggregate discriminative loss(AD-loss).The use of AD-loss and softmax-loss can increase the discriminativeness of the learned hash *** results show that on pool and ocean datasets,which were collected in pools and oceans,respectively,by using acoustic collectors,the proposed HADN performs better than other comparative models in terms of accuracy and mAP.

关键词： convolutional channel hash aggregate discriminative network aggregate discriminant loss waveform recognition

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Spatial Distribution Pattern and Influencing Factors of Bed-and-breakfasts(B&Bs)from the Perspective of Urban-rural Differences:A Case Study of Jiaodong Peninsula,China

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Chinese Geographical Science 2024年第4期34卷 752-763页

作者： WANG Xinyue MA Qian Management college Ocean University of ChinaQingdao 266100China

There are significant differences between urban and rural bed-and-breakfasts(B&Bs)in terms of customer positioning,economic strength and spatial *** identifying the differences in spatial characteristics and influencing factors of each type,is essential for creating urban and rural B&B agglomeration *** study used density-based spatial clustering of applications with noise(DBSCAN)and the multi-scale geographically weighted regression(MGWR)model to explore similarities and differences in the spatial distribution patterns and influencing factors for urban and rural B&Bs on the Jiaodong Peninsula of China from 2010 to *** results showed that:1)both urban and rural B&Bs in Jiaodong Peninsula went through three stages:a slow start from 2010 to 2015,rapid development from 2015 to 2019,and hindered development from 2019 to ***,urban B&Bs demonstrated a higher development speed and agglomeration intensity,leading to an increasingly evident trend of uneven development between the two sectors.2)The clustering scale of both urban and rural B&Bs continued to expand in terms of quantity and *** B&B clusters characterized by a limited number,but a higher likelihood of transitioning from low-level to high-level *** the number of rural B&B clusters steadily increased over time,their clustering scale was comparatively lower than that of urban B&Bs,and they lacked the presence of high-level clustering.3)In terms of development direction,urban B&B clusters exhibited a relatively stable pattern and evolved into high-level clustering centers within the main urban ***,rural B&Bs exhibited a more pronounced spatial diffusion effect,with clusters showing a trend of multi-center development along the coastline.4)Transport emerged as a common influencing factor for both urban and rural B&Bs,with the density of road network having the strongest explanatory power for their spatial *** terms of differences,populati

关键词： urban-rural bed-and-breakfasts(B&Bs) spatiotemporal evolution density-based spatial clustering of applications with noise(DBSCAN)model multi-scale geographically weighted regression(MGWR) Jiaodong Peninsula China

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Starlet:Network defense resource allocation with multi-armed bandits for cloud-edge crowd sensing in IoT

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Digital Communications and Networks 2024年第3期10卷 586-596页

作者： Hui Xia Ning Huang Xuecai Feng Rui Zhang Chao Liu college of Computer Science and Technology Ocean University of ChinaQingdao266100China

The cloud platform has limited defense resources to fully protect the edge servers used to process crowd sensing data in Internet of *** guarantee the network's overall security,we present a network defense resource allocation with multi-armed bandits to maximize the network's overall ***,we propose the method for dynamic setting of node defense resource thresholds to obtain the defender(attacker)benefit function of edge servers(nodes)and ***,we design a defense resource sharing mechanism for neighboring nodes to obtain the defense capability of ***,we use the decomposability and Lipschitz conti-nuity of the defender's total expected utility to reduce the difference between the utility's discrete and continuous arms and analyze the difference ***,experimental results show that the method maximizes the defender's total expected utility and reduces the difference between the discrete and continuous arms of the utility.

关键词： Internet of things Defense resource sharing Multi-armed bandits Defense resource allocation

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Classification of Sailboat Tell Tail Based on Deep Learning

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Journal of ocean University of China 2024年第3期23卷 710-720页

作者： CHANG Xiaofeng YU Jintao GAO Ying DING Hongchen LIU Yulong YU Huaming Department of Physical Education Ocean University of ChinaQingdao 266100China college of Big Data Qingdao University of Science and TechnologyQingdao 266061China college of oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China

The tell tail is usually placed on the triangular sail to display the running state of the air flow on the sail *** is of great significance to make accurate judgement on the drift of the tell tail of the sailboat during sailing for the best sailing *** it is difficult for sailors to keep an eye for a long time on the tell sail for accurate judging its changes,affected by strong sunlight and visual *** this case,we adopt computer vision technology in hope of helping the sailors judge the changes of the tell tail in ease with *** paper proposes for the first time a method to classify sailboat tell tails based on deep learning and an expert guidance system,supported by a sailboat tell tail classification data set on the expert guidance system of interpreting the tell tails states in different sea wind conditions,including the feature extraction *** the expression capabilities that vary with the computational features in different visual tasks,the paper focuses on five tell tail computing features,which are recoded by an automatic encoder and classified by a SVM *** experimental samples were randomly divided into five groups,and four groups were selected from each group as the training set to train the *** remaining one group was used as the test set for *** highest resolution value of the ResNet network was 80.26%.To achieve better operational results on the basis of deep computing features obtained through the ResNet network in the *** method can be used to assist the sailors in making better judgement about the tell tail changes during sailing.

关键词： tell tail sailboat classification deep learning

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Synergetic Bioproduction of Short-Chain Fatty Acids from Waste Activated Sludge Intensified by the Combined Use of Potassium Ferrate and Biosurfactants

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Journal of ocean University of China 2024年第3期23卷 695-709页

作者： CHEN Yanyan YAO Shuo ZHANG Dahai LI Xianguo FENG Lijuan college of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China

The synergetic effect and underlying mechanism of potassium ferrate(PF)with tea saponin(TS,a biosurfactant)in producing short chain fatty acids(SCFAs)from anaerobic fermentation of waste activated sludge(WAS)were explored in this *** results showed that 0.2 g PF(g TSS)^(-1)(total suspended solid)combined with 0.02 g TS(g TSS)^(-1) could further improve SCFAs’production,and the maximum SCFAs content reached 2008.7 mg COD L^(-1),which is 1.2 and 4.5 times higher than those with PF and TS individually added,respectively,and 5.3 times higher than that of blank WAS on Day *** the model substrates experiments,the degradation rates of bovine serum albumin and dextran with combination of PF and TS were 41.3%±0.1% and 48.5%±0.06%,respectively,on Day 3,which are lower than those in blank WAS(with degradation rates of 72.3%±0.5%and 90.3%±0.3%).It was revealed that the oxidative effect of PF and the solubilization of TS caused more organic matters to be dissolved out from WAS,providing a large number of biodegradable substances for subsequent SCFAs *** WAS pretreated with the combination of PF and TS,the relative abundances of Firmicutes increased from 6.4%(blank)to 38.6%,and that of Proteobacteria decreased from 41.8%(blank)to 21.8%.The combination of PF and TS promoted the hydrolysis process of WAS by enriching Firmicutes,and then increased acetic acid production by inhibiting Proteobacteria that consumed ***,at the genus level,acidogenesis bacteria(e.g.,Proteiniclasticum and Petrimonas)were enriched whereas SCFAs consuming bacteria(e.g.,Dokdonella)were inhibited.

关键词： waste activated sludge anaerobic fermentation potassium ferrate biosurfactant pretreatment

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Experimental Study on Vortex-Induced Vibration of Rough Risers Coupling with Interference Effect in Tandem Arrangement

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China ocean Engineering 2024年第3期38卷 394-407页

作者： HU Ze-bo LIU Zhen LI Peng GUO Hai-yan REN Xiao-hui HOU Hao HAO Lian-hong college of Civil Engineering and Architecture Shandong University of Science and TechnologyQingdao 266590China qingdao Key Laboratory of Marine Civil Engineering Materials and Structures Qingdao 266590China college of Engineering Ocean University of ChinaQingdao 266100China

In order to study the response law of vortex-induced vibration(VIV)of marine risers under the combined action of roughness and interference effects,and to reveal the coupling mechanism of roughness and interference effects on the riser,a VIV experiment of rough risers in tandem arrangement was conducted in a wave−current combined *** experiment characterized the risers’roughness by arranging different specifications of attachments on the surface of the *** rough risers with different roughness and smooth risers were arranged in tandem arrangement,with the rough risers arranged *** experimental results indicate that the suppression of the attachments on the downstream risers’vibration are more significant both in the CF and IL directions as the reduced velocity *** the downstream riser,the amplitude response of rough riser is more significantly weakened compared with the smooth one at high reduced *** the upstream risers,changes in the roughness and spacing ratio have an impact on their‘lock-in’*** the roughness of downstream risers is relatively large(0.1300)and the spacing between risers is small(S/D=4.0),the reduced velocity range of‘lock-in’region in the CF direction of upstream risers is obviously expanded,and the displacement in the‘lock-in’region is severer.

关键词： marine riser vortex-induced vibration tandem arrangement roughness interference effect

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Spatio-temporal variability of surface chlorophyll a in the Yellow Sea and the East China Sea based on reconstructions of satellite data of 2001-2020

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Journal of oceanology and Limnology 2024年第2期42卷 390-407页

作者： Weichen XIE Tao WANG Wensheng JIANG Key Laboratory of Marine Environment and Ecology Ocean University of ChinaQingdao 266100China college of oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China

Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental *** spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-2020 were investigated by reconstructing the MODIS Level 3 products with the data interpolation empirical orthogonal function(DINEOF)*** reconstructed results by interpolating the combined MODIS daily+8-day datasets were found better than those merely by interpolating daily or 8-day ***-a concentration in the YS and the ECS reached its maximum in spring,with blooms occurring,decreased in summer and autumn,and increased in late autumn and early *** performing empirical orthogonal function(EOF)decomposition of the reconstructed data fields and correlation analysis with several potential environmental factors,we found that the sea surface temperature(SST)plays a significant role in the seasonal variation of Chl a,especially during spring and *** increase of SST in spring and the upper-layer nutrients mixed up during the last winter might favor the occurrence of spring *** high sea surface temperature(SST)throughout the summer would strengthen the vertical stratification and prevent nutrients supply from deep water,resulting in low surface Chl-a *** sea surface Chl-a concentration in the YS was found decreased significantly from 2012 to 2020,which was possibly related to the Pacific Decadal Oscillation(PDO).

关键词： chlorophyll a(Chl a) data interpolation empirical orthogonal function(DINEOF) empirical orthogonal function(EOF)analysis Yellow Sea East China Sea

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Effect of dissolved organic nitrogen on the bloom of Prorocentrum donghaiense and Karenia spp. in the East China Sea coastal waters

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Acta oceanologica Sinica 2024年第6期43卷 71-85页

作者： Xiaoru Cui Guangming Zhen Jing Zhao Keqiang Li Xiulin Wang Key Laboratory of Marine Chemistry Theory and Technology/Frontiers Science Center for Deep ocean Multispheres and Earth System of Ministry of Education Ocean University of ChinaQingdao 266100China college of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China college of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China

Understan ding the mechanism of harmful algal bloom formation is vital for effectively preventing algal bloom outbreaks in coastal *** *** in the East China Sea show a significant correlation with nutrient ***,the impact of key components of nutrients,especially dissolved organic nitrogen(DON),on the blooms of Karenia *** not *** research is still *** this study,the cruise observations,field mesocosm-flask culture experiments,and a multinitrogen-tri-phytoplankton-detritus model(NTPD) are combined to reveal the quantitative influence of nutrient regimes on the shift of Prorocentrum donghaiense and Karenia *** the East China *** has a synchronism rhythm of *** spp.-diatom loop in the field culture experiment,which is consistent with the results of the cruise *** results showed that the processes of terrigenous DON(TeDON) and dissolved inorganic nitrogen(DIN:NO_(3)^(-)-N,NH_(4)^(+)-N) absorption promoted *** to become the dominant algae in the community;whereas the processes of DON from *** absorption promoted Karenia *** become the dominant algae in ambient DIN *** addition,the three-dimensional fluorescence components of humus C,tyrosine and fulvic acid can indicate the processes of growth and extinction of *** and Karenia spp.,*** study infers that *** and Karenia *** shift mechanism associated with the nutrient regime in coastal waters,which provides a scientific basis for the environmental management of coastal eco system health.

关键词： Karenia spp. Prorocentrum donghaiense nutrients multinitrogen-tri-phytoplankton-detritus model three-dimensional fluorescence

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Friction Characteristics Between Marine Clay and Construction Materials

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Journal of ocean University of China 2024年第2期23卷 427-437页

作者： KOU Hailei HUANG Jiaming CHENG Yang college of Engineering Ocean University of ChinaQingdao 266100China Fourth Division Organization Department of the CPC Qingdao Municipal CommitteeQingdao 266100China

Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore *** interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical *** between the surface roughness of structures,water content and interface friction angle were presented by model *** increase of water contents decreased the interface friction *** interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain *** roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different *** surface models with different roughness are established based on the structure data obtained by 3D *** Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular *** interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.

关键词： marine clay construction material interface friction behavior surface roughness Finite Element Method

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Large-scale particle trapping by acoustic vortices with a continuously variable topological charge

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Chinese Physics B 2024年第7期33卷 398-406页

作者：庄昊霏张清源胡格昊王青东杜立彬 college of ocean Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Department of Radiology the Affiliated Hospital of Qingdao UniversityQingdao 266000China college of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590China

Strengthened directivity with higher-order side lobes can be generated by the transducer with a larger radius at a higher frequency. The multi-annular pressure distributions are displayed in the cross-section of the acoustic vortices(AVs)which are formed by side lobes. In the near field, particles can be trapped in the valley region between the two annuli of the pressure peak, and cannot be moved to the vortex center. In this paper, a trapping method based on a sector transducer array is proposed, which is characterized by the continuously variable topological charge(CVTC). This acoustic field can not only enlarge the range of particle trapping but also improve the aggregation degree of the trapped particles. In the experiments, polyethylene particles with a diameter of 0.2 mm are trapped into the multi-annular valleys by the AV with a fixed topological charge. Nevertheless, by applying the CVTC, particles outside the radius of the AV can cross the pressure peak successfully and move to the vortex center. Theoretical studies are also verified by the experimental particles trapping using the AV with the continuous variation of three topological charges, and suggest the potential application of large-scale particle trapping in biomedical engineering.

关键词： acoustic vortices sector transducer array trapping particle continuously variable topological charge

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