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An improved algorithm based on equivalent sound velocity profile method at large incident angle

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Acta Oceanologica Sinica 2024年第2期43卷 161-167页

作者： Qianqian Li Qian Tong Fanlin Yang Qi Li Zhihao Juan Yu Luo College of Geodesy and geomatics Shandong University of Science and TechnologyQingdao 266590China College of Underwater Acoustic engineering Harbin Engineering UniversityHarbin 150001China

With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing *** classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam ***,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge *** analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial ***,an error correction algorithm based on polynomial fitting is *** simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.

关键词： equivalent sound speed profile ray tracing method large incident angle edge beam deep sea error correction multibeam echo-sounder system

Exploring the mechanical behavior and microstructure of compacted loess subjected to dry-wet cycles and chemical contamination

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Journal of Rock Mechanics and Geotechnical engineering 2024年第9期16卷 3673-3695页

作者： Yongpeng Nie Wankui Ni Xiangfei Lü Wenxin Tuo College of Geological engineering and geomatics Chang'an UniversityXi'an710054China department of Civil engineering Nagoya Institute of TechnologyNagoya466-8555Japan School of Water and Environment Chang'an UniversityXi'an710054China

Due to climatic factors and rapid urbanization,the soil in the Loess Plateau,China,experiences the coupled effects of dry-wet cycles and chemical *** the mechanical behavior and corresponding microstructural evolution of contaminated loess subjected to dry-wet cycles is essential to elucidate the soil degradation ***,direct shear and consolidation tests were performed to investigate the variations in mechanical properties of compacted loess contaminated with acetic acid,sodium hydroxide,and sodium sulfate during dry-wet *** mechanical response mechanisms were investigated using zeta potential,mineral chemical composition,and scanning electron microscopy(SEM)*** results indicate that the mechanical deterioration of sodium hydroxidecontaminated loess during dry-wet cycles decreases with increasing contaminant concentration,which is mainly attributed to the thickening of the electrical double layer(EDL)by Nat and the precipitation of calcite,as well as the formation of colloidal flocs induced by OH,thus inhibiting the development of large pores during the dry-wet *** contrast,the attenuation of mechanical properties of both acetic acid-and sodium sulfate-contaminated loess becomes more severe with increasing contaminant concentration,with the latter being more particularly *** is primarily due to the reduction of the EDL thickness and the erosion of cement in the acidic environment,which facilitates the connectivity of pores during dry-wet ***,the salt expansion generated by the drying process of saline loess further intensifies the structural ***,the mechanical performance of compacted loess is sensitive to both pollutant type and concentration,exhibiting different response patterns in the dry-wet cycling condition.

关键词： Contaminated loess Dry-wet cycles Compressibility Shear strength Microstructural evolution

Adaptation analysis and fusion correction method of CMIP6 precipitation simulation data on the Qinghai-Tibetan Plateau

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Journal of Mountain Science 2024年第2期21卷 555-573页

作者： PENG Hao QIN Dahui WANG Zegen ZHANG Menghan YANG Yanmei YONG Zhiwei School of Civil engineering and geomatics Southwest Petroleum UniversityChengdu 610500China School of Geoscience and technology Southwest Petroleum UniversityChengdu 610500China

In order to obtain more accurate precipitation data and better simulate the precipitation on the Tibetan Plateau,the simulation capability of 14 Coupled Model Intercomparison Project Phase 6(CMIP6)models of historical precipitation(1982-2014)on the Qinghai-Tibetan Plateau was evaluated in this *** indicate that all models exhibit an overestimation of precipitation through the analysis of the Taylor index,temporal and spatial statistical *** correct the overestimation,a fusion correction method combining the Backpropagation Neural Network Correction(BP)and Quantum Mapping(QM)correction,named BQ method,was *** this method,the historical precipitation of each model was corrected in space and time,*** correction results were then analyzed in time,space,and analysis of variance(ANOVA)with those corrected by the BP and QM methods,***,the fusion correction method results for each model were compared with the Climatic Research Unit(CRU)data for significance analysis to obtain the trends of precipitation increase and decrease for each *** results show that the IPSL-CM6A-LR model is relatively good in simulating historical precipitation on the Qinghai-Tibetan Plateau(R=0.7,RSME=0.15)among the uncorrected *** terms of time,the total precipitation corrected by the fusion method has the same interannual trend and the closest precipitation values to the CRU data;In terms of space,the annual average precipitation corrected by the fusion method has the smallest difference with the CRU data,and the total historical annual average precipitation is not significantly different from the CRU data,which is better than BP and ***,the correction effect of the fusion method on the historical precipitation of each model is better than that of the QM and BP *** precipitation in the central and northeastern parts of the plateau shows a significant increasing *** correlation coefficients between monthly

关键词： GCM CMIP6 Precipitation correction BP-QM fusion correction Spatio-temporal characteristics

An improved typhoon monitoring model based on precipitable water vapor and pressure

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Geodesy and Geodynamics 2024年第3期15卷 276-290页

作者： Junyu Li Haojie Li Lilong Liu Jiaqing Chen Yibin Yao Mingyun Hu Liangke Huang Fade Chen Tengxu Zhang Lv Zhou College of geomatics and Geoinformation Guilin University of TechnologyGuilin 541006China Guangxi Key Laboratory of Spatial Information and geomatics Guilin 541006China Qinzhou Institute of Surveying and Mapping for Housing and Urban-Rural Development Co. Ltd.Qinzhou 535000China School of Geodesy and geomatics Wuhan UniversityWuhan 430079China School of Resources and Environmental Science and engineering Hubei University of Science and TechnologyXianning 437100China

The potential of monitoring the movement of typhoons using the precipitable water vapor(PWV) has been confirmed. However, monitoring the movement of typhoon is focused on PWV, making it difficult to describe the movement of a typhoon in detail minutely and resulting in insufficient accuracy. Hence,based on PWV and meteorological data, we propose an improved typhoon monitoring mode. First, the European Centre for Medium-Range Weather Forecasts Reanalysis 5-derived PWV(ERA5-PWV) and the Global Navigation Satellite System-derived PWV(GNSS-PWV) were compared with the reference radiosonde PWV(RS-PWV). Then, using the PWV and atmospheric parameters derived from ERA5, we discussed the anomalous variations of PWV, pressure(P), precipitation, and wind speed during different typhoons. Finally, we compiled a list of critical factors related to typhoon movement, PWV and P. We developed an improved multi-factor typhoon monitoring mode(IMTM) with different models(i.e.,IMTM-I and IMTM-II) in different cases with a higher density of GNSS observation or only Numerical Weather Prediction(NWP) data. The IMTM was evaluated through the reference movement speeds of HATO and Mangkhut from the China Meteorological Observatory Typhoon Network(CMOTN). The results show that the root mean square(RMS) of the IMTM-I is 1.26 km/h based on ERA5-P and ERA5-PWV,and the absolute bias values are mostly within 2 km/h. Compared with the models considering the single factor ERA5-P/ERA5-PWV, the RMS of the IMTM-I is improved by 26.3% and 38.5%, respectively. The IMTM-II model manifests a residual of only 0.35 km/h. Compared with the single-factor model based on GNSS-PWV/P, the residual of the IMTM-II model is reduced by 90.8% and 84.1%, respectively. These results propose that the typhoon movement monitoring approach combining PWV and P has evident advantages over the single-factor model and is expected to supplement traditional typhoon monitoring.

关键词： Typhoon GNSS/ERA5 PWV Pressure Monitoring Improved model

The role of surface processes and mantle plumes in the formation of microcontinents: insights from numerical modeling and the Seychelles microcontinent case study

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Journal of Earth Science 2024年

作者： Zhijie Jia Pietro Sternai Jianbing Peng School of Geological engineering and geomatics， Chang'an University department of Earth and Environmental Sciences， University of Milan-Bicocca chool of Geological engineering and geomatics， Chang'an University

Mantle plumes and surface erosion and sediment deposition affect the modes of continental lithospheric rupturing in extensional tectonic settings， modulating the evolution of rifting margins. However， their relative contributions to the overall evolution of rifting margins and possible roles in the formation of microcontinent are still elusive. Here， we use coupled geodynamic and surface processes numerical modeling to assess the extent to which surface processes may determine the formation of microcontinent during lithospheric stretching in presence or absence of a mantle plume underneath. Our modeling results indicate that fast extension rates and hillslope (i.e.， diffusion) erosion promote ridge jump events and therefore the formation of microcontinents. On the contrary， efficient fluvial erosion and far-reaching sediment transport (i.e.， stream power erosion) inhibits ridge jump events and the formation of microcontinents. The ridge jump event and overall evolution in our numerical models is consistent with the shift from the Mascarene Ridge to the Carlsberg Ridge that determined the formation of the Seychelles microcontinent. We therefore speculate that hillslope erosion， rather than fluvial erosion， was predominant during the formation of the Seychelles， a possible indication of overall dry local climate conditions.

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Uncertainty quantification of inverse analysis for geomaterials using probabilistic programming

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Journal of Rock Mechanics and Geotechnical engineering 2024年第3期16卷 895-908页

作者： Hongbo Zhao Shaojun Li Xiaoyu Zang Xinyi Liu Lin Zhang Jiaolong Ren School of Civil engineering and geomatics Shandong University of TechnologyZibo255000China State Key Laboratory of Geomechanics and Geotechnical engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

Uncertainty is an essentially challenging for safe construction and long-term stability of geotechnical *** inverse analysis is commonly utilized to determine the physico-mechanical ***,conventional inverse analysis cannot deal with uncertainty in geotechnical and geological *** this study,a framework was developed to evaluate and quantify uncertainty in inverse analysis based on the reduced-order model(ROM)and probabilistic *** ROM was utilized to capture the mechanical and deformation properties of surrounding rock mass in geomechanical *** programming was employed to evaluate uncertainty during construction in geotechnical engineering.A circular tunnel was then used to illustrate the proposed framework using analytical and numerical *** results show that the geomechanical parameters and associated uncertainty can be properly obtained and the proposed framework can capture the mechanical behaviors under ***,a slope case was employed to demonstrate the performance of the developed *** results prove that the proposed framework provides a scientific,feasible,and effective tool to characterize the properties and physical mechanism of geomaterials under uncertainty in geotechnical engineering problems.

关键词： Geological engineering Geotechnical engineering Inverse analysis Uncertainty quantification Probabilistic programming

ASLP-DL—A Novel Approach Employing Lightweight Deep Learning Framework for Optimizing Accident Severity Level Prediction

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Computers, Materials & Continua 2024年第2期78卷 2535-2555页

作者： Saba Awan Zahid Mehmood department of Software engineering University of Engineering and TechnologyTaxila47050Pakistan department of Computer engineering University of Engineering and TechnologyTaxila47050Pakistan

Highway safety researchers focus on crash injury severity,utilizing deep learning—specifically,deep neural networks(DNN),deep convolutional neural networks(D-CNN),and deep recurrent neural networks(D-RNN)—as the preferred method for modeling accident *** learning’s strength lies in handling intricate relation-ships within extensive datasets,making it popular for accident severity level(ASL)prediction and *** prior success,there is a need for an efficient system recognizing ASL in diverse road *** address this,we present an innovative Accident Severity Level Prediction Deep Learning(ASLP-DL)framework,incorporating DNN,D-CNN,and D-RNN models fine-tuned through iterative hyperparameter selection with Stochastic Gradient *** framework optimizes hidden layers and integrates data augmentation,Gaussian noise,and dropout regularization for improved *** and factor contribution analyses identify influential *** on three diverse crash record databases—NCDB 2018–2019,UK 2015–2020,and US 2016–2021—the D-RNN model excels with an ACC score of 89.0281%,a Roc Area of 0.751,an F-estimate of 0.941,and a Kappa score of 0.0629 over the NCDB *** proposed framework consistently outperforms traditional methods,existing machine learning,and deep learning techniques.

关键词： Injury severity prediction deep learning feature

A Numerical Calculation Algorithm of the Inclination Function Based on the Representation of SO(3) Group

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 137-148页

作者： Yu-xiao Wei Wen-lin Tang department of Geophysics School of Geology Engineering and GeomaticsChang’An UniversityXi’an710064China Key Laboratory of Electronics and Information technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing100190China

In the determination of the Earth gravity field in satellite geodesy, the inclination functions represent the projection of data observed along the orbital plane of a satellite orbit into the sphere in the terrestial reference frame. The inclination functions in this work is studied from a group theoretical perspective. The inclination functions are proved to generate a representation of the SO(3) group. An orthogonal relation of the inclination functions is derived and some recurrence relations for the inclination functions are given, based on which an algorithm to calculate the inclination functions is proposed.

关键词： SO(3)group inclination function satellite geodesy representation of SO(3)

Development of design charts to predict the dynamic response of pile supported machine foundations

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Frontiers of Structural and Civil engineering 2024年第4期18卷 663-679页

作者： Deepthi SUDHI Sanjit BISWAS Bappaditya MANNA department of Civil engineering National Institute TechnologyWarangal 506004India department of Civil engineering Indian Institute of TechnologyDelhi 110016India

This paper proposes design charts for estimating imperative input parameters for continuum approach analysis of the nonlinear dynamic response of *** and analytical studies using continuum approach have been conducted on single and 2×2 grouped piles under coupled and vertical modes of vibration,for different dynamic forces and pile *** these design charts are derived from model piles,the charts have been validated for prototype pile foundations using scaling *** experimental responses of model piles are scaled up and these responses exhibit good agreement with analytical *** study also extends to estimation of the errors in computing frequency–amplitude responses with an increase in pile *** is found that,with an increase in pile length,the errors also *** effectiveness of the proposed design charts is also checked with data based on different field setups given in existing literature,and these charts are found to be ***,the developed design charts can be beneficial in estimating the input parameters for continuum approach analysis for determining the nonlinear responses of pile supported machine foundations.

关键词： pile foundation vertical vibration coupled vibration continuum approach soil-pile separation boundary zone parameters