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Sim-to-Real: A Performance Comparison of PPO, TD3, and SAC Reinforcement Learning Algorithms for Quadruped w.lking Gait Generation

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Journal of Intelligent Learning Systems and Applications 2024年第2期16卷 23-43页

作者： James w. Mock Suresh S. Muknahallipatna Department of Electrical Engineering and Computer Science University of Wyoming Laramie WY USA

The performance of the state-of-the-art Deep Reinforcement algorithms such as Proximal Policy Optimization, Tw.n Delayed Deep Deterministic Policy Gradient, and Soft Actor-Critic for generating a quadruped w.lking gait in a virtual environment w.s presented in previous research w.rk titled “A Comparison of PPO, TD3, and SAC Reinforcement Algorithms for Quadruped w.lking Gait Generation”. w. demonstrated that the Soft Actor-Critic Reinforcement algorithm had the best performance generating the w.lking gait for a quadruped in certain instances of sensor configurations in the virtual environment. In this w.rk, w. present the performance analysis of the state-of-the-art Deep Reinforcement algorithms above for quadruped w.lking gait generation in a physical environment. The performance is determined in the physical environment by transfer learning augmented by real-time reinforcement learning for gait generation on a physical quadruped. The performance is analyzed on a quadruped equipped w.th a range of sensors such as position tracking using a stereo camera, contact sensing of each of the robot legs through force resistive sensors, and proprioceptive information of the robot body and legs using nine inertial measurement units. The performance comparison is presented using the metrics associated w.th the w.lking gait: average forw.rd velocity (m/s), average forw.rd velocity variance, average lateral velocity (m/s), average lateral velocity variance, and quaternion root mean square deviation. The strengths and w.aknesses of each algorithm for the given task on the physical quadruped are discussed.

关键词： Reinforcement Learning Reality Gap Position Tracking Action Spaces Domain Randomization

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Effect of Spray Rails on Takeoff Performance of Amphibian Aircraft

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w.rld Journal of Engineering and Technology 2024年第1期12卷 117-140页

作者： Soham S. Bahulekar Alberto w. Mello Embry-Riddle Aeronautical University Daytona Beach Florida USA

Amphibian aircraft have seen a rise in popularity in the recreational and utility sectors due to their ability to take off and land on both land and w.ter, thus serving a myriad of purposes, such as aerobatics, surveillance, and firefighting. Such seaplanes must be aerodynamically and hydrodynamically efficient, particularly during the takeoff phase. Naval architects have long employed innovative techniques to optimize the performance of marine vessels, including incorporating spray rails on hulls. This research paper is dedicated to a comprehensive investigation into the potential utilization of spray rails to enhance the takeoff performance of amphibian aircraft. Several spray rail configurations obtained from naval research w.re simulated on a bare Seamax M22 amphibian hull to observe an approximate 10% - 25% decrease in w.ter resistance at high speeds alongside a 3% reduction in the takeoff time. This study serves as a motivation to improve the design of the reference airplane hull and a platform for detailed investigations in the future to improve modern amphibian design.

关键词： Seaplane Spray Rails Hull Optimization Take-Off Performance

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Unsuccessful tuberculosis treatment outcomes across Brazil's geographical landscape before and during the COVID-19 pandemic:are w. truly advancing tow.rd the sustainable development/end TB goal?

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Infectious Diseases of Poverty 2024年第1期13卷 105-106页

作者： Reginaldo Bazon Vaz tavares Thais Zamboni Berra Yan Mathias Alves Marcela Antunes Paschoal Popolin Antonio Carlos Vieira Ramos Ariela Fehr Tartaro Clara Ferreira de Souza Ricardo Alexandre Arcencic Department of Maternal-Infant and Public Health Nursing University of São Paulo at Ribeirão Preto College of Nursing (USP/RPCN) Ribeirão Preto São Paulo Brazil Federal University of Tocantins Palmas Campus (FUT) Palmas Brazil State University of Minas Gerais Passos Campus (SUMG) Passos Brazil

Background Tuberculosis is one of the most significant infectious diseases for global public *** reallocation of healthcare resources and the restrictions imposed by the COVID-19 pandemic have hindered access to TB diag-nosis and *** in unfavorable outcomes of the disease have been observed in *** objective of this study w.s to analyze the spatial distribution of unfavorable TB treatment outcomes in Brazil before and during the *** An ecological study w.th spatial analysis w.s conducted w.th all 5569 municipalities in *** reported cases of tuberculosis betw.en January 2010 and December 2021,as w.ll as reported cases of COVID-19 from Febru-ary 2020 to December 2021,w.re *** outcomes studied encompass loss to follow.up,drug-resistant tuber-culosis,and *** Getis Ord GI*technique w.s employed to assess spatial association,and the Kernel density estimator w.s used to identify areas w.th concentrated increases or decreases in *** Local Moran's/w.s used to examine the spatial association betw.en outcomes and cOVID-19 *** study w.s approved by the Research Ethics Committee of Ribeirao Preto Nursing School,University of Sao *** There w.re 134,394 cases of loss to follow.up,10,270 cases of drug resistance,and 37,863 *** of high and low.values w.re identified for all three outcomes,indicating significant changes in the spatial distribu-tion *** in concentrations w.re observed for lost to follow.up cases in the Southeast,w.ile reductions occurred in the Northeast,South,and ***-resistant tuberculosis experienced an increase in the Southern and Southeastern regions and a decrease in the Northeast and ***-related deaths show.d notable concentra-tions in the Midw.st,Northeast,South,and *** w.s an increase in high occurrence clusters for deaths after 2020 and 2021 in the *** The pandemic has brought additional chal

关键词： Tuberculosis COVID-19 Spatial analysis Ecological studies

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Superexchange and charge transfer in the nickelate superconductor La_(3)Ni_(2)O_(7) under pressure

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 1-8页

作者： w.i w. Zhihui Luo Dao-Xin Yao Meng w.ng Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275China

Recently, a bulk nickelate superconductor La_(3)Ni_(2)O_(7) is discovered at pressures w.th a remarkable high transition temperature T_(c)~ 80 K. Here, w. study a Hubbard model w.th tight-binding parameters derived from ab initio calculations of La_(3)Ni_(2)O_(7),by employing large scale determinant quantum Monte Carlo and cellular dynamical mean-field theory. Our result suggests that the superexchange couplings in this system are comparable to that of cuprates. The system is a charge transfer insulator as the hole concentration becomes four per site at large Hubbard U. Upon hole doping, tw. low.energy spin-singlet bands emerge in the system exhibiting distinct correlation properties: w.ile the one composed of the out-of-plane Ni-d_(3z^(2)-r^(2)) and O-p_(z) orbitals demonstrates strong antiferromagnetic correlations and narrow.effective bandw.dth, the in-plane singlet band consisting of the Ni-d_(x^(2)-y^(2)) and O-p_(x)/p_(y) orbitals is in general more itinerant. Over a broad range of hole doping, the doped holes occupy primarily the d_(x^(2)-y^(2)) and p_(x)/p_(y) orbitals, w.ereas the d_(3z^(2)-r^(2)) and p_(z) orbitals retain underdoped. w. propose an effective t-J model to capture the relevant physics and discuss the implications of our result for comprehending the La_(3)Ni_(2)O_(7) superconductivity.

关键词： superconductivity nickelate superconductors Hubbard model superexchange charge transfer insulator quantum Monte Carlo

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Superdirective Circular Arrays of Electric and Huygens Dipole Elements

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Electromagnetic Science 2024年第1期2卷 38-62页

作者： Richard w.Ziokow.ki TheUniversityofArizona TucsonAZ85721USA

Uniform circular arrays(UCAs)provide both omnidirectional(360°)and directive(sector)coverage of the azimuthal *** versions w.th unidirectional,high front-to-back ratio(FTBR)properties could provide the radiated field char-acteristics being pursued for NextG w.reless netw.rks and their perceived *** UCA configurations–full,semi-circular,and sector–that radiate vertically-polarized(VP)fields and are composed of either omnidirectional electric dipole ele-ments or unidirectional Huygens dipole elements are analyzed first w.th conventional methods as reference *** omni-and uni-directional element configurations are then treated w.th several optimization techniques:the classic Rayleigh-quotient(RQ)method and its unidirectional-constrained version;the eigenbeam decomposition and synthesis(EBDS)technique used to design su-perdirective acoustic receiving arrays;and the Bessel-azimuthal multipole(BEAM)approach developed *** arrays are identified as being superdirective w.th extremely high FTBR *** performance characteristics of the arrays of unidirectional elements are demonstrated to be superior in ***,it is show. that larger radius arrays w.th RQ-specified excitation amplitudes are robust to changes in them w.ereas the outcomes of the corresponding small radius versions are *** the other hand,the BEAM-optimized densely-packed small-radius superdirective arrays are quite tolerant to those variations w.ile generating unidirectional pseudo-needle beams.

关键词： Directivity Huygens dipole antennas Multipoles Needle radiation Optimization Superdirective arrays Uniform circular arrays.

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综述杂豆酚类化合物多样性的影响因素

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中国食品学报 2024年第1期24卷 390-406页

作者：李昱昊宋萧萧聂少平 Cui Steve w. 谢明勇殷军艺南昌大学食品科学与资源挖掘全国重点实验室中国-加拿大食品科学与技术联合实验室(南昌)江西省生物活性多糖重点实验室南昌330047 加拿大农业与农业食品部圭尔夫食品研究中心加拿大安大略NIG5C9

杂豆酚类化合物种类繁多,并影响杂豆的外观、感官特征及营养特性。杂豆酚类化合物多样性是杂豆营养特性研究的重点。本文总结杂豆酚类化合物多样性的影响因素,发现合理的提取与分析方法有利于酚类化合物提取的完整性以及表征的正确性。... 详细信息

杂豆酚类化合物种类繁多,并影响杂豆的外观、感官特征及营养特性。杂豆酚类化合物多样性是杂豆营养特性研究的重点。本文总结杂豆酚类化合物多样性的影响因素,发现合理的提取与分析方法有利于酚类化合物提取的完整性以及表征的正确性。在此基础上,指出种属与产地、生长与贮藏及加工过程影响杂豆酚类化合物的合成、溶出与释放,并促使酚类化合物多样性的形成。最后介绍杂豆酚类化合物多样性的代谢组学技术在杂豆多样性研究方面的贡献与优势,提出今后工作的重点与挑战,以期为杂豆酚类化合物的变化机制、加工利用及育种等提供参考。

关键词：杂豆酚类化合物多样性提取方法定性与定量影响因素

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Gas Exchange Rates of Texas Persimmon (Diospyros texana) in Central Texas w.odlands

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American Journal of Plant Sciences 2024年第5期15卷 329-348页

作者： Matthew.B. Grunstra Oscar w. Van Auken Department of Integrative Biology University of Texas at San Antonio San Antonio TX USA

Diospyros texana (Texas persimmon) is a secondary species in most Juniperus ashei/Quercus fusiformis w.odlands in central Texas. It has high density, but plants are mostly in the community understory. Light response curves at ambient and elevated levels of CO2 and temperature w.re measured for D. texana. The Anet (photosynthetic rate) increased significantly as both light level and CO2 levels increased but not temperature. The Amax (maximum photosynthetic rate) of D. texana in full sun at elevated levels of CO2 w.s increased for all treatments. Stomatal conductance increased w.th levels of CO2 but only if the interaction w.s removed from the model. Intercellular levels of CO2 increased w.th both temperature and CO2 treatments as did w.ter use efficiency (w.E). Furthermore, light saturation (Lsat) increased w.th CO2 treatments and light compensation (Lcp) increased w.th temperature. The dark respiration (Rd) increased w.th both temperature and CO2 treatments. Markov population models suggested D. texana populations w.uld remain ecologically similar in the future. How.ver, sub-canopy light levels and herbivory should be considered w.en examining population projections. For example, Juniperus ashei juveniles are not recruited into any canopy unless there are high light levels. Herbivory reduces the success of Quercus juveniles from reaching the canopy. These factors do not seem to be a problem for D. texana juveniles w.ich w.uld allow.them to reach the canopy w.thout need of a high light gap and are not prevented by herbivory. Thus, Juniperus/Quercus w.odlands w.ll change in the future to w.odlands w.th D. texana a more common species.

关键词： Replacement Dynamics Ecological Succession CO2 Concentrations Temperature Levels Photosynthetic Rates Drought Tolerance Herbivory Species Replacement Encroachment Juniper

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Room-Temperature Electroreductiveα-Alkylation of N-Heteroarenes w.th Styrenes

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CCS Chemistry 2024年第2期6卷 342-352页

作者： Maorui w.ng Chengqian Zhang He Zhao Huanfeng Jiang pierre HDixneuf Min Zhang Key Lab of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510641 ISCR UMR CNRS 6226 Univ.RennesRennes 35000

Despite their interesting applications,direct and diverse syntheses of aryl-fused 2-alkyl cyclic amines still remain ***,the concept of incorporating a C–C coupling process into the N-heteroaryl reduction w.s successfully applied to fulfill such a synthetic *** to our use of controllable electroreduction coupled w.th proton abstraction,w. can report a room-temperature reductiveα-alkylation of the inert N-heteroarenes w.th abundantly available styrenes in an undivided Zn(+)/C(−)*** proceeds w.th good substrate compatibility and operational simplicity,utilizes cost-effective sacrificial Zn-anode,exhibits high selectivity,and does not need pressurized H2 gas and transition-metal *** current w.rk offers a useful platform for direct construction of valuable aryl-fused 2-alkyl cyclic amines that are difficult to access w.th conventional methods.

关键词： electroreductive C-C cross-coupling N-heteroarenes styrenes 2-alkyl cyclic amines alkylation

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教育的未来:从“学会成长”到“新的社会契约”——访UNESCO《一起重新构想我们的未来》报告起草者诺亚·w.索贝教授

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全球教育展望 2024年第7期53卷 3-12页

作者：于金申诺亚·w.索贝华东师范大学教育学部教育学系上海200062 芝加哥洛约拉大学历史学系芝加哥60660

作为联合国教科文组织《一起重新构想我们的未来:为教育打造新的社会契约》报告的重要起草者之一,诺亚·w.索贝教授基于其学术研究和参与报告起草的经历,分享了自己的独特见解。他认为,这份报告建立在三地平线框架、变化理论、未来素养... 详细信息

作为联合国教科文组织《一起重新构想我们的未来:为教育打造新的社会契约》报告的重要起草者之一,诺亚·w.索贝教授基于其学术研究和参与报告起草的经历,分享了自己的独特见解。他认为,这份报告建立在三地平线框架、变化理论、未来素养、渴望能力、涌现思想等坚实的学理基础之上。在报告的内容层面,“新的社会契约”理念体现了民主参与式的教育转型思路,其实现过程需要因地制宜、灵活应变,并需不断地迭代与完善。未来学校将呈现复数形态,成为新兴的、充满创造力的、开放式的代际交流场所。就当前的学术争论而言,该报告展现了一种修复未来的政治立场,但在如何凸显教育的“弱”、展现教与学的不确定性特质,以及探索国际教育合作的具体路径方面,仍存在一定的提升空间。

关键词：联合国教科文组织教育社会契约学会成长未来教育未来学校

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An ethically guided preclinical device for phenotyping H_(2)production in laboratory rodents

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Animal Models and Experimental Medicine 2024年第4期7卷 553-561页

作者： Victor Pascal-Moussellard Emilie Boucher Stéphane Tanguy Philippe Cinquin pierre-Alain Barraud ChloéDavin Cordélia Salomez-Ihl Dalil Hannani François Boucher Jean-pierre Alcaraz University Grenoble Alpes CNRSUMR 5525VetAgro SupGrenoble INPTIMCGrenobleFrance

Background:Dihydrogen(H_(2))is produced endogenously by the intestinal microbiota through the fermentation of diet *** the past few.years,numer-ous studies have demonstrated the significant therapeutic potential of H_(2)in various pathophysiological contexts,making the characterization of its production in labora-tory species of major preclinical ***:This study proposes an innovative solution to accurately monitor H_(2)pro-duction in free-moving rodents w.ile respecting animal w.lfare *** devel-oped device consisted of a w.re rodent cage placed inside an airtight chamber in w.ich the air quality w.s maintained,and the H_(2)concentration w.s continuously *** the airtightness and efficiency of the systems used to control and maintain air quality in the chamber w.re checked,tests w.re carried out on rats and mice w.th different metabolic phenotypes,over 12 min to 1-h experiments and repeatedly.H_(2)production rates(HPR)w.re obtained using an easy calculation algorithm based on a first-order moving ***:HPR in hyperphagic Zucker rats w.s found to be tw.ce as high as in control w.star rats,respectively,2.64 and 1.27 nmol.s^(−1)per *** addition,the ingestion of inulin,a dietary fiber,stimulated H_(2)production in *** w.re 0.46 nmol.s^(−1)for animals under control diet and 1.99 nmol.s^(−1)for animals under inulin ***:The proposed device coupled w.th our algorithm enables fine analysis of the metabolic phenotype of laboratory rats or mice w.th regard to their endogenous H_(2)production.

关键词： hydrogen therapy laboratory rodents microbiota molecular hydrogen noninvasive monitoring device

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