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Estimation of the TBM advance rate under hard rock conditions using XGBoost and Bayesian optimization

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Underground Space 2021年第5期6卷 506-515页

作者： jian Zhou Yingui qiu Shuangli zhu Danial Jahed Armaghani Manoj Khandelwal Edy Tonnizam Mohamad School of Resources and Safety Engineering Central South UniversityChangsha 410083China Department of Civil Engineering Faculty of EngineeringUniversity of Malaya50603 Kuala LumpurMalaysia School of Engineering Information Technology and Physical SciencesFederation University AustraliaBallaratAustralia Centre of Tropical Geoengineering(GEOTROPIK) School of Civil EngineeringFaculty of EngineeringUniversiti Teknologi Malaysia81310 Johor BahruMalaysia

The advance rate(AR)of a tunnel boring machine(TBM)under hard rock conditions is a key parameter in the successful implementation of tunneling *** this study,we improved the accuracy of prediction models by employing a hybrid model of extreme gradient boosting(XGBoost)with Bayesian optimization(BO)to model the TBM *** develop the proposed models,1286 sets of data were collected from the Peng Selangor Raw Water Transfer tunnel project in *** database consists of rock mass and intact rock features,including rock mass rating,rock quality designation,weathered zone,uniaxial compressive strength,and Brazilian tensile *** specifications,including revolution per minute and thrust force,were considered to predict the TBM *** accuracies of the predictive models were examined using the root mean squares error(RMSE)and the coefficient of determination(R^(2))between the observed and predicted yield by employing a five-fold cross-validation *** showed that the BO algorithm can capture better hyper-parameters for the XGBoost prediction model than can the default XGBoost *** robustness and generalization of the BO-XGBoost model yielded prominent results with RMSE and R^(2) values of 0.0967 and 0.9806(for the testing phase),*** results demonstrated the merits of the proposed BO-XGBoost *** addition,variable importance through mutual information tests was applied to interpret the XGBoost model and demonstrated that machine parameters have the greatest impact as compared to rock mass and material properties.

关键词： TBM performance Advance rate XGBoost Bayesian optimization Predictive modeling

Multi-Branch Fault Line Location Method Based on Time Difference Matrix Fitting

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Energy Engineering 2024年第1期121卷 77-94页

作者： Hua Leng Silin He jian qiu Feng Liu Xinfei Huang Jiran zhu School of Electrical and Information Engineering Hunan UniversityChangsha410082China Distribution Network Technical Center State Grid Hunan Electric Power Research InstituteChangsha410007China Technical Center China Energy Construction Group Hunan Thermal Power ConstructionZhuzhou412011China School of Electrical and Information Engineering Changsha University of Science and TechnologyChangsha410076China

The distribution network exhibits complex structural characteristics,which makes fault localization a challenging *** when a branch of the multi-branch distribution network fails,the traditional multi-branch fault location algorithm makes it difficult to meet the demands of high-precision fault localization in the multi-branch distribution network *** this paper,the multi-branch mainline is decomposed into single branch lines,transforming the complex multi-branch fault location problem into a double-ended fault location *** on the different transmission characteristics of the fault-traveling wave in fault lines and non-fault lines,the endpoint reference time difference matrix S and the fault time difference matrix G were *** time variation rule of the fault-traveling wave arriving at each endpoint before and after a fault was comprehensively *** realize the fault segment location,the least square method was *** was used to find the first-order fitting relation that satisfies the matching relationship between the corresponding row vector and the first-order function in the two matrices,to realize the fault segment ***,the time difference matrix is used to determine the traveling wave velocity,which,combined with the double-ended traveling wave location,enables accurate fault location.

关键词： Multi-branch lines distribution network fault location double-ended traveling wave positioning least square method

高校社团志愿者参与残疾人体育服务的组织与建构

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体育科研 2004年第1期25卷 72-75页

作者：陈颖川吉建秋朱继华吴明南京财经大学体育部江苏南京210003 南京理工大学体育部江苏南京210094 南京大学体育部江苏南京210008

通过问卷调查、数据统计、文献资料,对大学生志愿者参与残疾人体育服务的效应、内涵、发展进行了较为全面的分析研究,并提出了建议。

关键词：高校社团志愿者残疾人体育服务大学生

甲状腺动脉栓塞术治疗甲状腺功能亢进的疗效分析

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医学影像学杂志 2004年第5期14卷 357-359页

作者：柴小民黄求理褚建平郭俊宇孙建河宁波市第一人民医院浙江宁波315010

目的 :探讨甲状腺动脉介入栓塞治疗甲亢的方法及临床疗效。方法 :选择 3例临床确诊甲亢患者 ,经DSA下用PVA微粒行双侧甲状腺上动脉及一侧下动脉栓塞。结果 :3例增粗的甲状腺动脉已被基本栓塞 ,腺体染色消失。栓塞后临床随访 1～ 4个月 ... 详细信息

目的 :探讨甲状腺动脉介入栓塞治疗甲亢的方法及临床疗效。方法 :选择 3例临床确诊甲亢患者 ,经DSA下用PVA微粒行双侧甲状腺上动脉及一侧下动脉栓塞。结果 :3例增粗的甲状腺动脉已被基本栓塞 ,腺体染色消失。栓塞后临床随访 1～ 4个月 ,术前T34.0～ 10 .4nmol/L ,平均 6 .8± 3.14SD ,T4 193.7～ 4 0 2nmol/L ,平均 2 6 5 .6 3± 10 8.15SD ,术后T3降至 3.5～ 9.3nmol/L ,平均 5 .11± 2 .89SD ,T4降至 182 .0～ 339.3nmol/L ,平均 2 2 8.87± 81.11SD。甲状腺B超 ,甲状腺肿大小术前 2 .5～ 5 .9cm ,术后缩小至 1.5～ 4 .3cm。临床症状逐渐缓解 ,未闻及明显颈部血管杂音。术后不良反应 ,栓塞综合征经对症处理后症状消失。结论 :介入治疗甲亢是一种安全有效替代内、外科治疗的新方法。

关键词：甲状腺机能亢进症动脉栓塞疗效

腹腔镜下经腹腔、后腹腔肾囊肿去顶减压术的效果观察

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蚌埠医学院学报 2016年第8期41卷 1026-1028页

作者：唐喆任春凯杨登伦乙从亮余秋建朱巍安徽省淮北市人民医院泌尿外科 235000

目的:探讨腹腔镜下经腹腔、后腹腔肾囊肿去顶减压术的临床应用效果。方法:90例肾囊肿患者根据手术方法不同分为3组,每组各30例。A组行经后腹腔镜肾囊肿去顶减压术,B组行经腹腔镜肾囊肿去顶减压术,C组行开放性肾囊肿去顶术。对3组患者的... 详细信息

目的:探讨腹腔镜下经腹腔、后腹腔肾囊肿去顶减压术的临床应用效果。方法:90例肾囊肿患者根据手术方法不同分为3组,每组各30例。A组行经后腹腔镜肾囊肿去顶减压术,B组行经腹腔镜肾囊肿去顶减压术,C组行开放性肾囊肿去顶术。对3组患者的手术效果进行比较。结果:A组、B组患者手术时间、术中出血量、胃肠功能恢复时间和住院时间均显著少于C组(P0.05)。结论:与开放性肾囊肿去顶术相比,腹腔镜手术具有创伤小、疗效好、恢复快等优点;经后腹腔镜肾囊肿去顶术相对于经腹腔镜肾囊肿去顶术手术耗时更短,并发症更少。

关键词：肾囊肿经腹腔后腹腔

Response of harmonically and stochastically excited strongly nonlinear oscillators with delayed feedback bang-bang control

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第1期10卷 54-61页

作者： Chang-shui FENG Wei-qiu zhu Institute of Mechatronic Engineering Hangzhou Dianzi University Hangzhou 310018 China State Key Laboratory of Fluid Power Transmission and Control Department of Mechanics Zhejiang University Hangzhou 310027 China

We studied the response of harmonically and stochastically excited strongly nonlinear oscillators with delayed feedback bang-bang control using the stochastic averaging method. First, the time-delayed feedback bang-bang control force is expressed approximately in terms of the system state variables without time delay. Then the averaged It6 stochastic differential equations for the system are derived using the stochastic averaging method. Finally, the response of the system is obtained by solving the Fokker-Plank-Kolmogorov （FPK） equation associated with the averaged lt6 equations. A Duffing oscillator with time-delayed feedback bang-bang control under combined harmonic and white noise excitations is taken as an example to illus- trate the proposed method. The analytical results are confirmed by digital simulation. We found that the time delay in feedback bang-bang control will deteriorate the control effectiveness and cause bifurcation of stochastic jump of Duffing oscillator.

关键词： Nonlinear system Delayed feedback bang-bang control Combined harmonic and white noise excitation Stochastic averaging Stationary response Stochastic jump

A highly-selective biomimetic potassium channel

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National Science Review 2024年第8期11卷 187-195页

作者： Junliang zhu Hu qiu Wanlin Guo Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education State Key Laboratory of Mechanics and Control for Aerospace Structures Institute for Frontier ScienceNanjing University of Aeronautics and Astronautics

Reproducing the outstanding selectivity achieved by biological ion channels in artificial channel systems can revolutionize applications ranging from membrane filtration to single-molecule sensing technologies,but achieving this goal remains a ***,inspired by the selectivity filter structure of the KcsA potassium channel,we propose a design of biomimetic potassium nanochannels by functionalizing the wall of carbon nano tubes with an array of arranged carbonyl oxygen *** extensive molecular dynamics simulations show that the biomimetic nanochannel exhibits a high K+permeation rate along with a high K+/Na+selectivity *** free energy calculations suggest that the low Na+permeability is the result of the higher energy barrier for Na+than K+at the channel entrance and ion binding *** addition,reducing the number of ion binding sites leads to an increase in the permeation rate but a decrease in *** findings not only hold promise for the design of high-performance membranes but also help understand the mechanism of selective ion transport in biological ion channels.

关键词： biomimetic design carbon nanotube K+/Na+ selectivity molecular dynamics simulations

Dynamics of a prey-predator system under Poisson white noise excitation

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Acta Mechanica Sinica 2014年第5期30卷 739-745页

作者： Shan-Shan Pan Wei-qiu zhu Department of Mechanics State Key Lab of Fluid Power Transmission and ControlZhejiang University

The classical Lotka-Volterra （LV） model is a well-known mathematical model for prey-predator ecosystems. In the present paper, the pulse-type version of stochastic LV model, in which the effect of a random natural environment has been modeled as Poisson white noise, is in- vestigated by using the stochastic averaging method. The averaged generalized It6 stochastic differential equation and Fokkerlanck-Kolmogorov （FPK） equation are derived for prey-predator ecosystem driven by Poisson white noise. Approximate stationary solution for the averaged generalized FPK equation is obtained by using the perturbation method. The effect of prey self-competition parameter e2s on ecosystem behavior is evaluated. The analytical result is confirmed by corresponding Monte Carlo （MC） simulation.

关键词： Prey-predator ecosystem Poisson white noise Stochastic averaging- Approximate stationary solution. Per turbation method

On the stochastic dynamics of molecular conformation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第9期8卷 1401-1407页

作者： DENG Mao-lin zhu Wei-qiu Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

An important functioning mechanism of biological macromolecules is the transition between different conformed states due to thermal fluctuation. In the present paper, a biological macromolecule is modeled as two strands with side chains facing each other, and its stochastic dynamics including the statistics of stationary motion and the statistics of conformational transition is studied by using the stochastic averaging method for quasi Hamikonian systems. The theoretical results are confirmed with the results from Monte Carlo simulation.

关键词： Biological macromolecule Thermal fluctuation Stationary statistics Transition time Stochastic averaging method