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Context-aware reinforcement learning for cooling operation of data centers with an Aquifer Thermal Energy Storage

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Energy and AI 2024年第3期17卷 233-246页

作者： Lukas Leindals Peter Grønning Dominik Franjo Dominković Rune Grønborg Junker Department of Applied Mathematics and Computer Science Technical University of DenmarkDenmark

Data centers are often equipped with multiple cooling units. Here, an aquifer thermal energy storage (ATES) system has shown to be efficient. However, the usage of hot and cold-water wells in the ATES must be balanced for legal and environmental reasons. Reinforcement Learning has been proven to be a useful tool for optimizing the cooling operation at data centers. Nonetheless, since cooling demand changes continuously, balancing the ATES usage on a yearly basis imposes an additional challenge in the form of a delayed reward. To overcome this, we formulate a return decomposition, Cool-RUDDER, which relies on simple domain knowledge and needs no training. We trained a proximal policy optimization agent to keep server temperatures steady while minimizing operational costs. Comparing the Cool-RUDDER reward signal to other ATES-associated rewards, all models kept the server temperatures steady at around 30 °C. An optimal ATES balance was defined to be 0% and a yearly imbalance of −4.9% with a confidence interval of [−6.2, −3.8]% was achieved for the Cool 2.0 reward. This outperformed a baseline ATES-associated reward of 0 at −16.3% with a confidence interval of [−17.1, −15.4]% and all other ATES-associated rewards. However, the improved ATES balance comes with a higher energy consumption cost of 12.5% when comparing the relative cost of the Cool 2.0 reward to the zero reward, resulting in a trade-off. Moreover, the method comes with limited requirements and is applicable to any long-term problem satisfying a linear state-transition system.

关键词： Data centers ATES Smart energy systems Reinforcement learning Delayed rewards

REMnO3（RE=Pr,Nd,Sm,Eu,Gd） perovskite as efficient catalysts for oxygen reduction reaction

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Journal of Rare Earths 2024年第11期42卷 2078-2087页

作者： Rakesh Ranjan Mahalik Siba Soren Ipsha Hota A.K.Debnath K.P.Muthe Purnendu Parhi Department of Chemistry Ravenshaw University technical Physics Division Bhabha Atomic Research Centre

Rare earth metal based perovskite emerges as important catalytic material for energy production and *** ABO3type materials are now the focus of research in the field of oxygen reduction and evolution ***,in this work we evaluated the oxygen reduction properties of the synthesized one-dimensional REMnO3（RE=Pr,Nd,Sm,Eu and Gd）.The one-dimensional REMnO3prepared by the hydrothermal synthesis route results in pure phase perovskite on *** perovskite was characte rized with X-ray diffraction,Fourier transform-infrared（FT-IR）,field emission-scanning electron microscopy（FE-SEM）,transmission electron microscopy（TEM） and X-ray photoelectron spectroscopy（XPS）.The oxygen reduction reaction activities were investigated with the help of electrochemical workstation that consists of three-electrode system immersed in 0.1 mol/L KOH electrolyte solution saturated with *** Koutechy-Levich plot obtained from rotating ring disk electrode shows all the prepared catalysts follow 4e-processes during oxygen *** effect of "A" site cation variation in REMnO3 on oxygen reduction reaction is ***3showed better onset potential for oxygen reduction reaction among the prepared rare earth ***3having high RE:Mn ratio（A-site rich co mpositions） promotes oxygen reduction reaction（ORR） *** the perovs kites showed good oxygen reduction property with high stability and methanol tolerance.

关键词： Electrocatalytic activity Oxygen reduction reaction (ORR) Perovskite Rare earths REMnO3 SmMnO3

Boosting liver regeneration: kinase inhibitor as a new tool to prevent liver failure

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Signal Transduction and Targeted Therapy 2024年第8期9卷 3145-3146页

作者： Anna Sichler Norbert Huser Klaus-Peter Janssen Department of Surgery School of Medicine and HealthTechnical University of MunichMunichGermany

In a recent manuscript in Cell,a first-in-class small molecule inhibitor of the kinase MKK4(mitogen-activated protein kinase kinase 4)was described that greatly enhances liver regeneration after partial hepatectomy in animal models,with an excellent safety profile in humans.1 The findings of Zwirner et *** promise to alter the clinical management of liver failure in critically ill patients.

关键词： liver al. clinical

Antibiotic ciprofloxacin removal from aqueous solutions by electrochemically activated persulfate process:Optimization,degradation pathways,and toxicology assessment

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Journal of Environmental Sciences 2024年第9期143卷 85-98页

作者： Elif Yakamercan Ahmet Aygün Halis Simsek Environmental Engineering Department Bursa Technical UniversityBursaTurkey Agricultural and Biological Engineering Department Purdue UniversityWest LafayetteINUSA

Ciprofloxacin(CIP)is a commonly used antibiotic in the fluoroquinolone group and is widely used in medical and veterinary medicine disciplines to treat bacterial *** CIP is discharged into the sewage system,it cannot be removed by a conventional wastewater treatment plant because of its recalcitrant *** this study,boron-doped diamond anode and persulfate were used to degrade CIP in an aquatic solution by creating an electrochemically activated persulfate(EAP)*** added to the system as a coactivator and the process was called EAP+*** effects of independent variables,including pH,Fe^(2+),persulfate concentration,and electrolysis time on the systemwere optimized using the response surface *** results showed that the EAP+Fe process removed 94%of CIP under the following optimum conditions:A pH of 3,persulfate/Fe^(2+)concentration of 0.4 mmol/L,initial CIP concentration 30 mg/L,and electrolysis time of 12.64 *** removal efficiency was increased from 65.10%to 94.35%by adding Fe^(2+)as a transition *** degradation products,7 pathways,and 78 intermediates of CIP were studied,and three of those intermediates(m/z 298,498,and 505)were *** toxicological analysis based on toxicity estimation software results indicated that some degradation products of CIP were toxic to targeted animals,including fathead minnow,Daphnia magna,Tetrahymena pyriformis,and *** optimumoperation costswere similar in EAP and EAP+Fe processes,approximately 0.54€/m^(3).

关键词： Ciprofloxacin Response surface methodology Electrochemically activated persulfate Electrooxidation

Design of a large-scale model for wind tunnel test of a multiadaptive flap concept

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Chinese Journal of Aeronautics 2024年第2期37卷 58-80页

作者： Mürüvvet Sinem SICIM DEMIRCI Rosario PECORA Metin Orhan KAYA Aeronautical Engineering Department Istanbul Technical UniversityIstanbulTurkey Industrial Engineering Department University of Naples Federico IINapoliItaly

The design and application of morphing systems are ongoing issues compelling the aviation *** Clean Sky-program represents the most significant aeronautical research ever launched in Europe on advanced technologies for greening next-generation *** primary purpose of the program is to develop new concepts aimed at decreasing the effects of aviation on the environment,increasing reliability,and promoting eco-friendly *** ambitions are pursued through research on enabling technologies fostering noise and gas emissions reduction,mainly by improving aircraft aerodynamic *** the Clean Sky framework,a multimodal morphing flap device was designed based on tight industrial requirements and tailored for large civil aircraft *** flap is deployed in one unique setting,and its cross section is morphed differently in take-off and landing to get the necessary extra lift for the specific flight ***,during the cruise,the tip of the flap is deflected for load control and induced drag *** manufacturing the first flap prototype,a high-speed(Ma=0.3),large-scale test campaign(geometric scale factor 1:3)was deemed necessary to validate the performance improvements brought by this novel system at the aircraft *** the other hand,the geometrical scaling of the flap prototype was considered impracticable due to the unscalability of the embedded mechanisms and actuators for shape ***,a new architecture was conceived for the flap model to comply with the scaled dimensions requirements,withstand the relevant loads expected during the wind tunnel tests and emulate the shape transition capabilities of the true-scale *** strategies were developed to effectively morph the model during wind tunnel tests while ensuring the robustness of each morphed configuration and maintaining adequate stiffness levels to prevent undesirable deviations from the intended aerodynamic ***,

关键词： Morphing structures Smart aircraft Morphing flap Adaptive systems Finger-like ribs Wind tunnel tests Large-scale morphing archi-tectures Variable camber airfoil

Research advances in enhanced coal seam gas extraction by controllable shock wave fracturing

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International Journal of Coal Science & Technology 2024年第3期11卷 1-31页

作者： Chaojun Fan Hao Sun Sheng Li Lei Yang Bin Xiao Zhenhua Yang Mingkun Luo Xiaofeng Jiang Lijun Zhou College of Mining Liaoning Technical UniversityFuxin123000China College of Safety Science and Engineering Liaoning Technical UniversityFuxin123000China Energy Business Department Shanxi Lu’an Chemical GroupChangzhi046200China

With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal *** controllable shock wave(CSW),as a new method for enhancing permeability of coal seam to improve gas extraction,features in the advantages of high efficiency,eco-friendly,and low *** order to better utilize the CSW into gas extraction in coal mine,the mechanism and feasibility of CSW enhanced extraction need to be *** this paper,the basic principles,the experimental tests,the mathematical models,and the on-site tests of CSW fracturing coal seams are reviewed,thereby its future research directions are *** on the different media between electrodes,the CSW can be divided into three categories:hydraulic effect,wire explosion and excitation of energetic materials by detonating *** the process of propagation and attenuation of the high-energy shock wave in coal,the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal *** stronger the strength of the CSW is,the more cracks created in the coal is,and the greater the length,width and area of the cracks *** repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength,but excessive shock frequency will also damage the coal structure,resulting in the limited effect of the enhanced gas *** the influence of ground stress,the crack propagation in coal seam will be *** difference of horizontal principal stress has a significant impact on the shape,propagation direction and connectivity of the CSW induced *** permeability enhancement effect of CSW is affected by the breakage degree of coal *** shock wave is absorbed by the broken coal,which may hinder the propagation of CSW,resulting in a poor effect of permeability *** arranging two a

关键词： Controllable shock wave Permeability enhancement Gas extraction Basic principle Experimental test Mathematical models On-site test

Guest Editorial:Special Section on Battery Energy Storage Systems for Net-zero Power Systems and Markets

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 321-322页

作者： Pierluigi Mancarella Nikos Hatziargyriou Chongqing Kang The university of Melbourne MelbourneAustralia The university of Manchester ManchesterUK National technical university of Athens(NTUA) AthensGreece Tsinghua university BeijingChina IEEE

Battery energy storage technologies have witnessed both dramatic cost reduction and technical evolution in recent *** is leading to widespread deployment of battery energy storage systems(BESSs)worldwide,particularly to support operation of power grids with already deep penetration of *** the development of new battery technologies with different power-to-energy ratios and for various engineering applications,BESSs could play a strategic role towards a net-zero energy *** opportunities are emerging for BESSs to participate in several markets,provide different grid services,and perform“value stacking”,eventually allowing development of new business cases and improved BESS *** configurations that are“behind the meter”,“in front of the meter”,hybrid plants co-located with renewables,and so forth,are only some of the exciting propositions that are being seen in different countries and at different scales,from highly distributed(virtual power plants),to neighbourhood-level(community batteries),to utility scale.

关键词： Battery battery eventually

A Survey of Synthetic Data Augmentation Methods in Machine Vision

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Machine Intelligence Research 2024年第5期21卷 831-869页

作者： Alhassan Mumuni Fuseini Mumuni Nana Kobina Gerrar Cape Coast technical university Cape CoastDL 50Ghana university of Mines and Technology Tarkwa237Ghana

The standard approach to tackling computer vision problems is to train deep convolutional neural network(CNN)models using large-scale image datasets that are representative of the target ***,in many scenarios,it is often challenging to obtain sufficient image data for the target *** augmentation is a way to mitigate this challenge.A common practice is to explicitly transform existing images in desired ways to create the required volume and variability of training data necessary to achieve good generalization *** situations where data for the target domain are not accessible,a viable workaround is to synthesize training data from scratch,i.e.,synthetic data *** paper presents an extensive review of synthetic data augmentation *** covers data synthesis approaches based on realistic 3D graphics modelling,neural style transfer(NST),differential neural rendering,and generative modelling using generative adversarial networks(GANs)and variational autoencoders(VAEs).For each of these classes of methods,we focus on the important data generation and augmentation techniques,general scope of application and specific use-cases,as well as existing limitations and possible ***,we provide a summary of common synthetic datasets for training computer vision models,highlighting the main features,application domains and supported ***,we discuss the effectiveness of synthetic data augmentation *** this is the first paper to explore synthetic data augmentation methods in great detail,we are hoping to equip readers with the necessary background information and in-depth knowledge of existing methods and their attendant issues.

关键词： Data augmentation generative modelling neural rendering data synthesis synthetic data neural style transfer(NsT)

Assessing the impacts of traffic calming at network level:A multimodal agent-based simulation

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第1期11卷 41-54页

作者： Eftychia Zargiannaki Panagiotis G.Tzouras Eleni Antoniou Christos Karolemeas Konstantinos Kepaptsoglou School of Rural Surveying and Geoinformatics EngineeringNational Technical University of AthensZografou 15780Greece

The reduction of speed limits in urban roads through traffic calming schemes intends to ensure safer traffic conditions among road users by reducing the probability related to the occurrence of severe *** it from a different perspective,traffic calming measures can potentially resolve congestion problems at the same time by lowering the overall accessibility and attractiveness of private cars in urban *** study proposes a new methodological approach to explore and assess the direct impacts of traffic calming in the transport system efficiency of a metropolitan *** multi-agent transport simulation(MATSim)and Open-Berlin scenario are utilized to perform this simulation *** developing a new external tool,the free flow speed and road capacity of each network link is updated based on new speed limits and different compliance rates,which are defined per road hierarchy *** test scenarios that are formulated present radical conditions,where the speed limit in most urban roads of Berlin drops to 30 km/h or even 15 km/*** findings of this study show a considerably high increase in trips,passenger hours,and passenger kilometers using public transport modes,when traffic calming links are introduced,the reserve change is observed in private cars *** the speed limits are decreased in inner urban roads in most of the scenarios,the decrease of average travel speed of private cars is not so high as it was ***,private cars are used for longer distances in all test *** drivers seem to use already existed motorways and private road to *** simulations,driver compliance to the new speed limits seems to be a determinant factor that is strongly influenced by the design interventions applied in a traffic calming area.

关键词： Agent-based simulation Traffic calming Impact assessment Urban road network