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Predicting the coefficient of friction in a sliding contact by applying machine learning to acoustic emission data

Friction 2024年第6期12卷 1299-1321页

作者： Robert GUTIERREZ Tianshi FANG Robert MAINWARING Tom REDDYHOFF Tribology Group Department of Mechanical EngineeringImperial College LondonExhibition RoadLondon SW72AZUK Shell Global Solutions(US)inc.Shell technology Center Houston 3333 Highway 6 SouthHoustonTX 77082USA Shell International Petroleum Company Limited Shell CentreYork RoadLondon SE17NAUK

It is inc.easingly important to monitor sliding interfaces within machines,sinc. this is where both energy is lost,and failures *** emission(AE)techniques offer a way to monitor contacts remotely without requiring transparent or electrically conductive ***,acoustic data from sliding contacts is notoriously complex and difficult to ***,we simultaneously measure coefficient of friction(with a conventional force transducer)and acoustic emission(with a piezoelectric sensor and high acquisition rate digitizer)produced by a steel‒steel rubbing *** data is then used to train machine learning(ML)algorithms(e.g.,Gaussian process regression(GPR)and support vector machine(SVM))to correlated acoustic emission with *** training requires the dense AE data to first be reduced in size and a range of processing techniques are assessed for this(e.g.,down-sampling,averaging,fast Fourier transforms(FFTs),histograms).Next,fresh,unseen AE data is given to the trained model and the resulting friction predictions are compared with the directly measured *** is excellent agreement between the measured and predicted friction when the GPR model is used on AE histogram data,with root mean square(RMS)errors as low as 0.03 and Pearson correlation coefficients reaching ***,predictions remain accurate despite changes in test conditions such as normal load,reciprocating frequency,and stroke *** paves the way for remote,acoustic measurements of friction in inaccessible locations within machinery to inc.ease mechanical efficiency and avoid costly failure/needless maintenance.

关键词： acoustic emission condition monitoring friction machine learning Gaussian process regression support vector machine

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Tiny Det: accurately detecting small objects within 1 GFLOPs

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Science China(Information Sciences) 2023年第1期66卷 318-319页

作者： Shaoyu CHEN Tianheng CHENG Jiemin FANG Qian ZHANG Yuan LI Wenyu LIU Xinggang WANG School of Electronic Information and Communications Huazhong University of Science and Technology Institute of Artificial Intelligence Huazhong University of Science and Technology Horizon Robotics inc. Google inc.

Dear editor,Object detection plays an important role in computer vision,and has gradually become the technical foundation of many applications. However, the inference procedure of advanced detection models requires ma... 详细信息

关键词： Economic and social effects

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Learning to Combine Answer Boundary Detection and Answer Re-ranking for Phrase-Indexed Question Answering

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Chinese Journal of Electronics 2022年第5期31卷 938-948页

作者： WEN Liang SHI Haibo ZHANG Xiaodong SUN Xin WEI Xiaochi WANG Junfeng CHENG Zhicong YIN Dawei WANG Xiaolin LUO Yingwei WANG Houfeng Department of Computer Science and technology Peking University Peng Cheng Laboratory Baidu inc.

Phrase-indexed question answering(PIQA) seeks to improve the inference speed of question answering(QA) models by enforcing complete independence of the document encoder from the question encoder,and it shows that the constrained model can achieve significant efficiency at the cost of its accuracy. In this paper, we aim to build a model under the PIQA constraint while reducing its accuracy gap with the unconstrained QA models. We propose a novel framework —Ans DR,which consists of an answer boundary detector(Ans D)and an answer candidate ranker(Ans R). More specifically, Ans D is a QA model under the PIQA architecture and it is designed to identify the rough answer boundaries; and Ans R is a lightweight ranking model to finely rerank the potential candidates without losing the efficiency. We perform the extensive experiments on public datasets. The experimental results show that the proposed method achieves the state of the art on the PIQA task.

关键词： Real-time question answering Answer boundary detection Answer re-ranking Phrase-indexed question answering Answer span aware loss

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Strongly adaptive online learning over partial intervals

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Science China(Information Sciences) 2022年第10期65卷 107-121页

作者： Yuanyu WAN Wei-Wei TU Lijun ZHANG National Key Laboratory for Novel Software technology Nanjing University 4Paradigm inc.

To cope with changing environments, strongly adaptive algorithms that almost enjoy the optimal performance on every time interval have been proposed for online learning. However, the best regret bound of existing algorithms on each time interval with length τ is O((τlogT)1/2), and their complexities are inc.easing with a factor of O(log T), where T is the time horizon. In real-world applications, T could go to infinity,which means that even these logarithmic factors are unacceptable. In this paper, we propose to remove the logarithmic factors of existing algorithms by utilizing prior information of environments. Specifically, we assume a lower bound τ1and an upper bound τ2on how long the environment changes are given, and only focus on the performance over time intervals with length in [τ1, τ2]. Then, we propose a new algorithm with a refined set of intervals that can reduce the complexity and a simple weighting method that can cooperate with our interval set. Theoretical analysis reveals that the regret bound of our algorithm on any focused interval is optimal up to a constant factor. Both the regret bound and the computational cost per iteration are independent of T. Experimental results show that our algorithm outperforms the state-of-the-art algorithm.

关键词： online learning strongly adaptive changing environments weighting method regret bound

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Oxidized organic molecules in the tropical free troposphere over Amazonia

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National Science Review 2024年第1期11卷 174-184页

作者： Qiaozhi Zha Diego Aliaga Radovan Krejci Victoria A.Sinc.air Cheng Wu Giancarlo Ciarelli Wiebke Scholz Liine Heikkinen Eva Partoll Yvette Gramlich Wei Huang Markus Leiminger Joonas Enroth Otso Per?kyl? Runlong Cai Xuemeng Chen Alkuin Maximilian Koenig Fernando Velarde Isabel Moreno Tuukka Pet?j? Paulo Artaxo Paolo Laj Armin Hansel Samara Carbone Markku Kulmala Marcos Andrade Douglas Worsnop Claudia Mohr Federico Bianchi Institute for Atmospheric and Earth System Research/Physics University of Helsinki Joint International Research Laboratory of Atmospheric and Earth System Sciences Nanjing University Department of Environmental Science & Bolin Centre for Climate Research Stockholm University Department of Chemistry and Molecular Biology University of Gothenburg Institute for Ion and Applied Physics University of Innsbruck Ionicon Analytik GmbH Laboratory for Atmospheric Physics Institute for Physics Research Universidad Mayor de San Andrés Institute of Physics University of Sao Paulo Institute for Geosciences and Environmental Research (IGE) University of Grenoble Alpes Agrarian Sciences Institute Federal University of Uberl?ndia Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Department of Atmospheric and Oceanic Sciences University of Maryland Aerodyne Research Inc. Department of Environmental System Science ETH Zürich Switzerland and Laboratory of Atmospheric Chemistry Paul Scherrer Institute

New particle formation(NPF) in the tropical free troposphere(FT) is a globally important source of cloud condensation nuclei, affecting cloud properties and climate. Oxidized organic molecules(OOMs)produced from biogenic volatile organic compounds are believed to contribute to aerosol formation in the tropical FT, but without direct chemical observations. We performed in situ molecular-level OOMs measurements at the Bolivian station Chacaltaya at 5240 m above sea level, on the western edge of Amazonia. For the first time, we demonstrate the presence of OOMs, mainly with 4–5 carbon atoms, in both gas-phase and particle-phase(in terms of mass contribution) measurements in tropical FT air from Amazonia. These observations, combined with air mass history analyses, indicate that the observed OOMs are linked to isoprene emitted from the rainforests hundreds of kilometers away. Based on particle-phase measurements, we find that these compounds can contribute to NPF, at least the growth of newly formed nanoparticles, in the tropical FT on a continental scale. Thus, our study is a fundamental and significant step in understanding the aerosol formation process in the tropical FT.

关键词： oxidized organic molecules tropical aerosol formation Amazon free troposphere

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Phosphorylated protein chip combined with artificial intelligence tools for precise drug screening

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Journal of Biomedical Research 2024年第3期38卷 195-205页

作者： Katsuhisa Horimoto Yuki Suyama Tadamasa Sasaki Kazuhiko Fukui Lili Feng Meiling Sun Yamin Tang Yixuan Zhang Dongyin Chen Feng Han SOCIUM inc. Tokyo 1350064Japan International Medical Center Saitama Medical UniversitySaitama 350-1298Japan Artificial Intelligence Research Center National Institute of Advanced Industrial Science and TechnologyTokyo 1350064Japan Department of Informatics and Data Science Sanyo-Onoda City UniversityYamaguchi 7560884Japan International Joint Laboratory for Drug Target of Critical Illnesses School of PharmacyNanjing Medical UniversityNanjingJiangsu 211166China Department of Physiology School of Basic Medical SciencesNanjing Medical UniversityNanjingJiangsu 211166China Gusu School Nanjing Medical UniversitySuzhouJiangsu 215001China National Vaccine Innovation Platform Nanjing Medical UniversityNanjingJiangsu 211166China

We have developed a protein array system,named"Phospho-Totum",which reproduces the phosphorylation state of a sample on the *** protein array contains 1471 proteins from 273 known signaling *** to the activation degrees of tyrosine kinases in the sample,the corresponding groups of substrate proteins on the array are phosphorylated under the same *** addition to measuring the phosphorylation levels of the 1471 substrates,we have developed and performed the artificial intelligence-assisted tools to further characterize the phosphorylation state and estimate pathway activation,tyrosine kinase activation,and a list of kinase inhibitors that produce phosphorylation states similar to that of the *** Phospho-Totum system,which seamlessly links and interrogates the measurements and analyses,has the potential to not only elucidate pathophysiological mechanisms in diseases by reproducing the phosphorylation state of samples,but also be useful for drug discovery,particularly for screening targeted kinases for potential drug kinase inhibitors.

关键词： Phospho-Totum protein array signal transduction pathways artificial intelligence tools drug screening

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Application of Horizontal Well Seismic Geo-Steering technology in XX Block Development

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Open Journal of Yangtze Oil and Gas 2024年第3期9卷 65-74页

作者： Xuecheng Jia Xiaoyi Cheng Hui Ma Shilei Lu Xin Yang Shuo Wang Xiang Li BGP Geological Research Center inc. CNPC Zhuozhou China No.6 Oil Production Company Petro China Changqing Oilfield Company CNPC Xian China Pipe China Group Beijing Pipe Co. Ltd. Beijing China

During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such as deep burial depth (>2000 m), thin coal sweet spot (3 m), and significant short-distance structural fluctuations. The challenges caused a high risk of missing targets and running out of the target layers, as well as difficulties in cementing and completion due to uneven well trajectories. To address these challenges, this paper focuses on solving the issues through detailed precise geological modeling, optimized trajectory design, and accurate seismic geology Steerable Drilling. 1) Based on reasonable velocity field construction and Time-Depth transformation, a precise directional model is constructed using the layer-by-layer approximation princ.ple with reference to marker layers, improving the accuracy of the target spot and avoiding premature or delayed entry into the target;2) Based on a precise geological model, the dip angle of the strata ahead and the development of sweet spots are clearly defined, enabling optimized trajectory design for horizontal wells;3) Using “1 + N” dynamic modeling to update the geological model in real-time during the drilling process, and actively guide the drill bit through the horizontal segment smoothly by using multi-information judgment of the drill bit position. The actual drilling of 80 completed horizontal wells in this area show: That this approach effectively ensures the smooth trajectory and high-quality drilling rate of the horizontal well in the coal seam, providing a basis for subsequent hydraulic fracturing and inc.easing single-well production. At the same time, it has certain potential value and significance for similar coalbed methane developments under similar geological conditions.

关键词： Seismic Geo-Steerable Horizontal Wells Coalbed Methane Marker Layers

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Interworking between Modbus and internet of things platform for industrial services

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Digital Communications and Networks 2024年第2期10卷 461-471页

作者： Sherzod Elamanov Hyeonseo Son Bob Flynn Seong Ki Yoo Naqqash Dilshad JaeSeung Song Department of Convergence Engineering for Intelligent Drone Sejong UniversitySouth Korea SyncTechno inc South Korea Exacta Global Smart Solutions USA Coventry University UK

In the era of rapid development of Internet of Things(IoT),numerous machine-to-machine technologies have been applied to the industrial *** to the divergence of IoT solutions,the industry is faced with a need to apply various technologies for automation and *** fact leads to a demand for an establishing interworking mechanism which would allow smooth interoperability between heterogeneous *** of the major protocols widely used today in industrial electronic devices is ***,data generated by Modbus devices cannot be understood by IoT applications using different protocols,so it should be applied in a couple with an IoT service layer ***2M,a global IoT standard,can play the role of interconnecting various protocols,as it provides flexible tools suitable for building an interworking framework for industrial ***,in this paper,we propose an interworking architecture between devices working on the Modbus protocol and an IoT platform implemented based on oneM2M *** the proposed architecture,we introduce the way to model Modbus data as oneM2M resources,rules to map them to each other,procedures required to establish interoperable communication,and optimization methods for this *** analyze our solution and provide an evaluation by implementing it based on a solar power management use *** results demonstrate that our model is feasible and can be applied to real case scenarios.

关键词： Internet of things Interoperability Interworking Modbus oneM2M

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Improvement of maximum power point tracking in photovoltaic arrays in different environments using hybrid algorithms

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Optoelectronics Letters 2024年第1期20卷 28-34页

作者： ZHANG Jiuchao REN Guangjun XUE Yuming XIA Dan WANG Jiangchao HU Zhaoshuo Institute of New Energy Intelligence Equipment School of Integrated Circuit Science and EngineeringTianjin University of TechnologyTianjin 300384China

When the photovoltaic(PV)system is generating PV power,the partial shading(PS)condition will cause multiple peaks in the power-voltage curve,and changes in light intensity and ambient temperature will cause the curve to *** maximum power point tracking(MPPT)methods,such as the inc.emental conductance(inc.method,have the problem of being trapped in the local optimal *** optimization algorithms,such as particle swarm optimization(PSO),have problems with oscillation and low tracking efficiency near the global maximum power point(GMPP).As a result,a hybrid algorithm CS-inc.based on the cuckoo search(CS)algorithm and the perturb and observe(P&O)approach is proposed in this *** light intensity remains constant,the light intensity changes in steps,and the partial shade scenario are *** results show that the MPPT improves accuracy,speed,and stability.

关键词： power maximum optimization

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Propagation and Dispersion Characteristics of Scholte Wave in VTI Media with the Presence of Irregular Seabed

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Journal of Earth Science 2024年第2期35卷 722-725页

作者： Xiaobo Liu Yun Wang Jianlei Zhang Haifeng Chen Hua Zhang School of Ocean Sciences China University of GeosciencesBeijing 100083China Key Laboratory of Polar Geology and Marine Mineral Resources China University of GeosciencesBeijing 100083China School of Geophysics and Information technology China University of GeosciencesBeijing 100083China Research&Development Center BGP IncCNPCZhuozhou 072751China National Engineering Research Center for Oil and Gas Exploration Computer Software Beijing 100080China

INTRODUCTION Surface waves propagating along the seafloor are general ly called Scholte waves,and were first discovered and studied in the early 1950s(Kugler et al.,2005;Buchen and Ben-Hador,1996).Scholte waves exhibit a dispersion phenomenon,which implies that their velocity varies with ***-frequency Scholte waves can propagate over long distances on the seabed with little attenuation(Bohlen et al.,2004).The particle mo tion of Scholte waves in a solid medium changes from a retro grade to a prograde ellipse(Klein et al.,2005;McMechan and Yedlin,1981).

关键词： seabed Dispersion implies

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