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Design and Experimental Testing of a Moving Coil Actuator with Compensation Coil

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 707-716页

作者： Boyuan Yin Xianwu Zeng john Frederick Eastham Emelie Nilsson Jean-francois Rouquette Jean Rivenc Ludovic Ybanez Xiaoze Pei Department of Electronics&Electrical Engineering University of BathBathBA27AYUnited Kingdom Airbus UpNext BlangnacFrance Airbus CRT BlangnacFrance Department of Mechanical Engineering University of BathBathBA27AYUnited Kingdom

Hydrogen-powered electric aircraft have attracted significant interests aiming to achieve decarbonization *** DC electric networks are facing great challenges in DC fault protection *** interrupters are widely used in low voltage and medium voltage power systems due to being environmentally friendly with low *** this paper a moving coil actuator with compensation coils for a vacuum interrupter,as part of a hybrid direct current circuit breaker,is designed and experimentally *** coils are used to improve operating speed compared with original moving coil *** between four possible connections of compensation coils and original moving coil actuator are carried *** results show comparisons between different connections of actuator coils in terms of opening time and coil current with a range of pre-charged capacitor *** performance of each actuator connection is also *** actuator with compensation coils is shown to have a higher current rising rate and achieve faster opening speed,which is a critical requirement for electric aircraft network *** parallel connection actuator achieves the highest opening speed within 3.5 ms with capacitor voltage of 50 V.

关键词： Circuit breaker compensation coil moving coil actuator vacuum interrupter

Optimized CUDA Implementation to Improve the Performance of Bundle Adjustment Algorithm on GPUs

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Journal of Software Engineering and Applications 2024年第4期17卷 172-201页

作者： Pranay R. Kommera Suresh S. Muknahallipatna john E. McInroy Department of Electrical Engineering and Computer Science University of Wyoming Laramie Wyoming USA

The 3D reconstruction pipeline uses the Bundle Adjustment algorithm to refine the camera and point parameters. The Bundle Adjustment algorithm is a compute-intensive algorithm, and many researchers have improved its performance by implementing the algorithm on GPUs. In the previous research work, “Improving Accuracy and Computational Burden of Bundle Adjustment Algorithm using GPUs,” the authors demonstrated first the Bundle Adjustment algorithmic performance improvement by reducing the mean square error using an additional radial distorting parameter and explicitly computed analytical derivatives and reducing the computational burden of the Bundle Adjustment algorithm using GPUs. The naïve implementation of the CUDA code, a speedup of 10× for the largest dataset of 13,678 cameras, 4,455,747 points, and 28,975,571 projections was achieved. In this paper, we present the optimization of the Bundle Adjustment algorithm CUDA code on GPUs to achieve higher speedup. We propose a new data memory layout for the parameters in the Bundle Adjustment algorithm, resulting in contiguous memory access. We demonstrate that it improves the memory throughput on the GPUs, thereby improving the overall performance. We also demonstrate an increase in the computational throughput of the algorithm by optimizing the CUDA kernels to utilize the GPU resources effectively. A comparative performance study of explicitly computing an algorithm parameter versus using the Jacobians instead is presented. In the previous work, the Bundle Adjustment algorithm failed to converge for certain datasets due to several block matrices of the cameras in the augmented normal equation, resulting in rank-deficient matrices. In this work, we identify the cameras that cause rank-deficient matrices and preprocess the datasets to ensure the convergence of the ba algorithm. Our optimized CUDA implementation achieves convergence of the Bundle Adjustment algorithm in around 22 seconds for the largest dataset compared

关键词： Scene Reconstruction Bundle Adjustment Levenberg-Marquardt Non-Linear Least Squares Memory Throughput Computational Throughput Contiguous Memory Access CUDA Optimization

Intracellular organelle networks： Understanding their organization and communication through systems-level modeling and analysis

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Frontiers in Biology 2017年第1期12卷 7-18页

作者： Qinle ba Ge Yang Department of Biomedical Engineering Carnegie Mellon University Pittsburgh PA 15213 USA Department of Computational Biology Carnegie Mellon University Pittsburgh PA 15213 USA

baCKGROUND： Membrane-bound intracellular organelles are biochemically distinct compartments used by eukaryotic cells for serving specialized physiological functions and organizing their internal environment. Recent studies revealed surprisingly extensive communication between these organelles and highlighted the network nature of their organization and communication. Since organization and communication of the organelles are carried out at the systems level through their networks, systems-level studies are essential for understanding the underlying mechanisms. METHODS： We reviewed recent studies that used systems-level quantitative modeling and analysis to understand organization and communication of intracellular organelle networks. RESULTS： We first review modeling and analysis studies on how fusion/fission and degradation/biogenesis, two essential and closely related classes of activities of individual organelles, collectively mediate the dynamic organization of their networks. We then turn to another important aspect of the dynamic organization of the organelle networks, namely how organelles are physically connected within their networks, a property referred to as the topology of the networks in mathematics, and summarize some of their distinct properties. Lastly, we briefly review modeling and analysis studies that aim to understand communication between different organelle networks, focusing on cellular calcium homeostasis as an example. We conclude with a brief discussion of future directions for research in this area. CONCLUSIONS： Together, the reviewed studies provide critical insights into how diverse activities of individual organelles collectively mediate the organization and communication of their networks. They demonstrate the essential role of systems- level modeling and analysis in understanding complex behavior of such networks.

关键词： intracellular organelle organelle network organelle communication network analysis systems modeling

Georgetown University President And His Party Visit China

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Voice of Friendship 2008年第2期 20-21页

作者： ba Cuicui

Invited by the CPAFFC,john ***,president of Georgetown University of the United States,and his party visited Beijing and Xining from January 3 to *** Zhili,state councillor,Xu Kuangdi,vice chairman of the National Committee of the Chinese People’s Political Consultative Conference and president of the China-US Peoples Friendship Association(CUSPFA),Gao Yunlong,deputy governor of Qinghai Province respectively met with *** Vice President Li Xiaolin accompanied the delegation on its visit to *** delegation held academic discussions with professors of the Party School of the Central Committee of the Communist Party of China and visited Qinghai University where the two sides explored the possibility of cooperation.

关键词： visited delegation cooperation chairman party pres

US Georgetown University President john DeGioia Leads Delegation to China

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Voice of Friendship 2009年第4期 17-18页

作者： ba Cuicui

Invited by the CPAFFC, john J. DeGioia, president of Georgetown University of the U. S.,and his party visited Gansu, Jiangxi and Hubei provinces and Beijing from March 4 to 9. Liu Yandong, state councillor; Li Yuancha... 详细信息

关键词： visited Jiangxi party Hubei president delegation c

Free Cyclic Actions on Surfaces and the Borsuk-Ulam Theorem

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Acta Mathematica Sinica,English Series 2022年第10期38卷 1803-1822页

作者： Daciberg Lima GONCALVES john GUASCHI Vinicius Casteluber LAASS Departamento de Matematica IMEUniversidade de Sao PauloRua do Matao 1010 CEP:05508-090Sao Paulo-SPBrazil Normandie Univ. UNICAENCNRSLMNO14000 CaenFrance Universidade Federal da bahia IMEDepartamento de MatematicaAv.Milton SantosS/N Ondina CEP:40170-110Salvador-BABrazil

Let M and N be topological spaces,let G be a group,and letτ:G×M→M be a proper free action of *** this paper,we define a Borsuk-Ulam-type property for homotopy classes of maps from M to N with respect to the pair(G,τ)that generalises the classical antipodal Borsuk-Ulam theorem of maps from the n-sphere S^(n) to R^(n).In the cases where M is a finite pathwise-connected CWcomplex,G is a finite,non-trivial Abelian group,τis a proper free cellular action,and N is either R^(2) or a compact surface without boundary different from S^(2) and RP^(2),we give an algebraic criterion involving braid groups to decide whether a free homotopy class β∈[M,N]has the Borsuk-Ulam *** an application of this criterion,we consider the case where M is a compact surface without boundary equipped with a free actionτof the finite cyclic group *** terms of the orient ability of the orbit space Mof M by the actionτ,the value of n modulo 4 and a certain algebraic condition involving the first homology group of M,we are able to determine if the single homotopy class of maps from M to R^(2) possesses the Borsuk-Ulam property with respect to(Z_(n),τ).Finally,we give some examples of surfaces on which the symmetric group acts,and for these cases,we obtain some partial results regarding the Borsuk-Ulam property for maps whose target is R^(2).

关键词： Borsuk-Ulam theorem cyclic groups braid groups surfaces

Organic chemistry 5th ed.

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The Chemistry of Niobium Mineralisation at bayan Obo,Inner Mongolia,China:Constraints on the Hydrothermal Precipitation and Alteration of Nb-Minerals

2000年

作者： McMurry john. CAL n2005165293# ba0yba0y

来源：畅想之星图书光盘版（南... 评论

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地质学报 2012年第5期86卷 700-722页

作者： Martin SMITH john SPRATT School of Environment and Technology University of BrightonBrightonBN41 2HQU.K. Department of Mineralogy The Natural History MuseumLondonSW7 5BDU.K.

As well as world class Fe and REE resources the bayan Obo mineral deposits also hosts significant niobium resources(estimated as 2.2 Mt Nb with an average grade of 0.13 wt% Nb).Niobium in this study is primarily hosted in aeschynite-(Ce) and(Nd),but with subsidiary amounts of pyrochlore,fergusonite-(Ce),fersmite and *** we report on the paragenetic and textural setting of aeschynite,pyrochlore and fergusonite in the main ore bodies and in a carbonatite *** in a carbonatite sample is hosted in a phase tentatively(due to significant Ca,Mn and Ti contents) identified as fergusonite-(Ce).Aeschynite occurs overgrowing foliation in banded ores,in fractures and vugs in aegirine-rich rocks and in calcite *** composition in all settings is similar,but some examples in banded ores develop significant zonation in Y,Th and the REE,inferred to relate to buffering of halogen acid species to low levels by dissolution and fluoritisation of calcite,and the preferential precipitation of LREE from solution due to lower mineral solubility products compared to the *** lower in total concentration the ratios of REE in pyrochlore are similar to those of aeschynite and suggest the same metal *** crystallisation of pyrochlore probably relates to growth in paragenetic settings where carbonates had already been eliminated and hence the buffering of F-species activities in the hydrothermal fluid was *** aeschynite and pyrochlore show evidence of *** alteration of aeschynite resulted in leaching of A-site cations(Ca,REE,Th) and Nb,addition of Fe,and ultimately replacement by ba-Ti phases(baotite and bafertisite).Secondary,metamictisation enhanced,possibly supergene alteration of pyrochlore resulted in hydration,leaching of A-site cations leading to the development of lattice vacancies and increases in *** presence of hydrothermal Nb resources at bayan Obo suggests there may be potential for further Nb discoveries in the area,

关键词：地质学地层成矿 LREE

Differentiating Neonatal Dubin johnson Syndrome from Biliary Atresia: Start Simply

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Journal of Clinical and Translational Hepatology 2023年第3期11卷 523-524页

作者： Jaimy Villavicencio Kim john Birk Division of Gastroenterology and Hepatology University of Connecticut School of MedicineFarmingtonCTUSA

Dubin johnson syndrome usually appears in the second dec-ade of life, making differentiation from biliary atresia (ba) relatively easy. However, there are rare cases of neonatal Dubin johnson syndrome (nDJS) causing cholestasis in neo-nates that can be easily mistaken for other conditions, in-cluding ba. It is important to make a distinction between the two in neonates because nDJS is typically a benign condition and ba, if left untreated, has a high mortality rate.

关键词： typically rare nates