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arXiv 2024年

作者： Martín-Luna, Pablo Bonatto, Alexandre Bontoiu, Cristian Xia, Guoxing Resta-López, Javier Universitat de València Consejo Superior de Investigaciones Científicas Paterna46980 Spain Graduate Program in Information Technology and Healthcare Management Beam Physics Group Federal University of Health Sciences of Porto Alegre RS Porto Alegre90050-170 Brazil Department of Physics The University of Liverpool LiverpoolL69 3BX United Kingdom Department of Physics and Astronomy The University of Manchester ManchesterM13 9PL United Kingdom Universidad de Valencia Valencia46071 Spain The Cockcroft Institute Sci-Tech Daresbury WarringtonWA4 4AD United Kingdom

The interactions of charged particles moving paraxially in multi-walled carbon nanotubes (MWCNTs) may excite electromagnetic modes. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration. In this work, the excitation of wakefields in double-walled carbon nanotubes (DWCNTs) is studied by means of the linearized hydrodynamic theory. General expressions have been derived for the excited longitudinal and transverse wakefields and related to the resonant wavenumbers which can be obtained from the dispersion relation. In the absence of friction, the stopping power of the wakefield driver, modelled here as a charged macroparticle, can be written solely as a function of these resonant wavenumbers. The dependencies of the wakefields on the radii of the DWCNT and the driving velocity have been studied. DWCNTs with inter-wall distances much smaller than the internal radius may be a potential option to obtain higher wakefields for particle acceleration compared to single-walled carbon nanotubes (SWCNTs). © 2024, CC BY-NC-SA.

关键词： Charged particles

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Plasmonic Excitations in Double-Walled Carbon Nanotubes

SSRN

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SSRN 2024年

作者： Martín-Luna, Pablo Bonatto, Alexandre Bontoiu, Cristian Xia, Guoxing Resta-López, Javier Universitat de València - Consejo Superior de Investigaciones Científicas Paterna46980 Spain Graduate Program in Information Technology and Healthcare Management The Beam Physics Group Federal University of Health Sciences of Porto Alegre RS Porto Alegre90050-170 Brazil Department of Physics The University of Liverpool LiverpoolL69 3BX United Kingdom The Cockcroft Institute Sci-Tech Daresbury WarringtonWA4 4AD United Kingdom Department of Physics and Astronomy The University of Manchester ManchesterM13 9PL United Kingdom Universidad de Valencia Valencia46071 Spain

关键词： Charged particles

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Effects of the interdisciplinary robotic game to elementary school students’abilities of computational thinking and STEM 27

Effects of the interdisciplinary robotic game to elementary ...

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27th International Conference on Computers in Education, ICCE 2019

作者： Huang, Hsin-yin Shih, Ju-ling Huang, Shu-hsien Liang, Jyh-Chong Department of Information and Learning Technology National University of Tainan Taiwan Graduate Institute of Network Learning Technology National Central University Taiwan Department of Information Management National Chin-Yi University of Technology Taiwan Program of Learning Sciences National Taiwan Normal University Taiwan

ISBN: (纸本)9789869721448

In 21st century, problem solving, computational thinking (CT) and collaborative skills are essential skills to achieve. In this study, problem-solving aptitude including five CT dimensions and STEM attitudes were examined through questionnaires. Total of ninety-nine 5th-graders were involved in the interdisciplinary robotic game , which is designed to enhance the effectiveness of the new learning structure in the context of Great Voyage. It is found that CT dimensions has intersected correlations to the STEM aspects. Interdisciplinary education has positive effects to the students, and the curriculum would lead them to have better performance in the complex problem-solving situations. © ICCE 2019 - 27th International Conference on Computers in Education, Proceedings. All rights reserved.

关键词： Robotics

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Quality Analysis the E-PASTI System to Determine the Condition of the System and information Quality

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Journal of Physics: Conference Series 2021年第1期1807卷

作者： Bayu Nugraha Finki Dona Marleny Sfenrianto Sfenrianto Cinthya Edwina Information System Program Faculty of Science and Technology Sari Mulia University Banjarmasin South Kalimantan Indonesia Information Systems Management Department BINUS Graduate Program–Master of Information Systems Management Bina Nusantara University Jakarta Indonesia 11480

The purpose of this study is to evaluate the quality of secretarial, financial and staffing information systems at the Directorate General of AHU, known as the E-PASTI system. There are two variables analysed, namely system quality and information quality. Data collection using questionnaires that distributed to 123 employees who used the E-PASTI system but returned 93 questionnaires. Data quality analyst uses descriptive quantitative method. The results of the study are several conditions related to the system and information quality of E-PASTI. The quality can be a reference for the AHU Directorate General to improve the quality of E-PASTI that suits the needs of employees.

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Excitation of wakefields in carbon nanotubes: A hydrodynamic model approach

arXiv

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arXiv 2023年

作者： Martín-Luna, P. Bonatto, A. Bontoiu, C. Xia, G. Resta-López, J. Universitat de València Consejo Superior de Investigaciones Científicas Paterna46980 Spain Graduate Program in Information Technology and Healthcare Management The Beam Physics Group Federal University of Health Sciences of Porto Alegre RS Porto Alegre90050-170 Brazil Department of Physics The University of Liverpool LiverpoolL69 3BX United Kingdom The Cockcroft Institute Sci-Tech Daresbury WarringtonWA4 4AD United Kingdom Department of Physics and Astronomy The University of Manchester ManchesterM13 9PL United Kingdom Universidad de Valencia Valencia46071 Spain

The interactions of charged particles with carbon nanotubes may excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell constituting the nanotube wall. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration. In this work, the excitation of these wakefields is studied by means of the linearized hydrodynamic model. In this model, the electronic excitations on the nanotube surface are described treating the electron gas as a 2D plasma with additional contributions to the fluid momentum equation from specific solid-state properties of the gas. General expressions are derived for the excited longitudinal and transverse wakefields. Numerical results are obtained for a charged particle moving within a carbon nanotube, paraxially to its axis, showing how the wakefield is affected by parameters such as the particle velocity and its radial position, the nanotube radius, and a friction factor, which can be used as a phenomenological parameter to describe effects from the ionic lattice. Assuming a particle driver propagating on axis at a given velocity, optimal parameters were obtained to maximize the longitudinal wakefield amplitude. © 2023, CC BY.

关键词： Charged particles

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Plasmonic excitations in double-walled carbon nanotubes

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Results in Physics 2024年 60卷

作者： Martín-Luna, Pablo Bonatto, Alexandre Bontoiu, Cristian Xia, Guoxing Resta-López, Javier Instituto de Física Corpuscular (IFIC) Universitat de València - Consejo Superior de Investigaciones Científicas Paterna 46980 Spain Graduate Program in Information Technology and Healthcare Management and the Beam Physics Group Federal University of Health Sciences of Porto Alegre RS Porto Alegre 90050-170 Brazil Department of Physics The University of Liverpool Liverpool L69 3BX United Kingdom The Cockcroft Institute Sci-Tech Daresbury Warrington WA4 4AD United Kingdom Department of Physics and Astronomy The University of Manchester Manchester M13 9PL United Kingdom Instituto de Ciencia de los Materiales (ICMUV) Universidad de Valencia Valencia 46071 Spain

The interactions of charged particles moving paraxially in multi-walled carbon nanotubes may excite electromagnetic modes. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration and for obtaining brilliant radiation sources. In this work, the excitation of wakefields in double-walled carbon nanotubes is studied by means of the linearized hydrodynamic theory. General expressions have been derived for the excited longitudinal and transverse wakefields and related to the resonant wavenumbers which can be obtained from the dispersion relation. In the absence of friction, the stopping power of the wakefield driver, modelled here as a charged macroparticle, can be written solely as a function of these resonant wavenumbers. The dependencies of the wakefields on the radii of the double-walled carbon nanotubes and the driving velocity have been studied. Double-walled carbon nanotubes with inter-wall distances much smaller than the internal radius may be a potential option to obtain higher wakefields for particle acceleration compared to single-walled carbon nanotubes. © 2024 The Authors

关键词： Double-walled carbon nanotubes Hydrodynamic model Plasmons Wakefield

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Exploring ultra-high-intensity wakefields in carbon nanotube arrays: An effective plasma-density approach

arXiv

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arXiv 2022年

作者： Bonatto, A. Xia, G. Apsimon, O. Bontoiu, C. Kukstas, E. Rodin, V. Yadav, M. Welsch, C.P. Resta-López, J. Graduate Program in Information Technology and Healthcare Management The Beam Physics Group Federal University of Health Sciences of Porto Alegre Porto Alegre RS 90050-170 Brazil Department of Physics and Astronomy The University of Manchester ManchesterM13 9PL United Kingdom The Cockcroft Institute Sci-Tech Daresbury WarringtonWA4 4AD United Kingdom Department of Physics The University of Liverpool LiverpoolL69 3BX United Kingdom Icmuv Instituto de Ciencia de Los Materiales Universidad de Valencia Valencia46071 Spain

Charged particle acceleration using solid-state nanostructures has attracted attention in recent years as a method of achieving ultra-high-gradient acceleration in the TV/m domain. More concretely, metallic hollow nanostructures could be suitable for particle acceleration through the excitation of wakefields by a laser or a high-intensity charged particle beam in a high-density solid-state plasma. For instance, due to their special channelling properties as well as optoelectronic and thermo-mechanical properties, carbon nanotubes could be an excellent medium for this purpose. This article investigates the feasibility of generating ultra-high gradient acceleration using carbon nanotube arrays, modelled as solid-state plasmas in conventional particle-in-cell simulations performed in a two-dimensional axisymmetric (quasi-3D) geometry. The generation of beam-driven plasma wakefields depending on different parameters of the solid structure is discussed in detail. Furthermore, by adopting an effective plasma-density approach, existing analytical expressions, originally derived for homogeneous plasmas, can be used to describe wakefields driven in periodic non-uniform plasmas. Copyright © 2022, The Authors. All rights reserved.

关键词： Plasma density

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The role of input imaging combination and ADC threshold on segmentation of acute ischemic stroke lesion using U-Net

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European Radiology 2023年第9期33卷 6157-6167页

作者： Li, Ya-Hui Lin, Shao-Chieh Chung, Hsiao-Wen Chang, Chia-Ching Peng, Hsu-Hsia Huang, Teng-Yi Shen, Wu-Chung Tsai, Chon-Haw Lo, Yu-Chien Lee, Tung-Yang Juan, Cheng-Hsuan Juan, Cheng-En Chang, Hing-Chiu Liu, Yi-Jui Juan, Chun-Jung Graduate Institute of Biomedical Electronics and Bioinformatics National Taiwan University Taipei Taiwan Department of Medical Imaging China Medical University Hsinchu Hospital No. 199 Sec. 1 Xinglong Rd. Zhubei City Hsinchu County 302 Hsinchu Taiwan Ph.D. Program in Electrical and Communication Engineering Feng Chia University Taichung Taiwan Department of Electrical Engineering National Taiwan University Taipei Taiwan Department of Management Science National Yang Ming Chiao Tung University Hsinchu Taiwan Department of Biomedical Engineering and Environmental Sciences National Tsing Hua University Hsinchu Taiwan Department of Electrical Engineering National Taiwan University of Science and Technology Taipei Taiwan Department of Radiology School of Medicine College of Medicine China Medical University Taichung Taiwan Department of Medical Imaging Medical University Hospital Taichung Taiwan Department of Neurology China Medical University Hospital Taichung Taiwan Cheng Ching Hospital Taichung Taiwan Master’s Program of Biomedical Informatics and Biomedical Engineering Feng Chia University Taichung Taiwan Department of Automatic Control Engineering Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung 40724 Taiwan Department of Biomedical Engineering The Chinese University of Hong Kong ERB1112 11/F William M.W. Mong Engineering Building N.T Shatin Hong Kong Multi-Scale Medical Robotics Center The Chinese University of Hong Kong N.T Shatin Hong Kong Department of Biomedical Engineering National Defense Medical Center Taipei Taiwan Department of Computer Science and Information Engineering National Taiwan University Taipei Taiwan

Background: To evaluate the effect of the weighting of input imaging combo and ADC threshold on the performance of the U-Net and to find an optimized input imaging combo and ADC threshold in segmenting acute ischemic stroke (AIS) lesion. Methods: This study retrospectively enrolled a total of 212 patients having AIS. Four combos, including ADC-ADC-ADC (AAA), DWI-ADC-ADC (DAA), DWI-DWI-ADC (DDA), and DWI-DWI-DWI (DDD), were used as input images, respectively. Three ADC thresholds including 0.6, 0.8 and 1.8 × 10^–3 mm²/s were applied. Dice similarity coefficient (DSC) was used to evaluate the segmentation performance of U-Nets. Nonparametric Kruskal–Wallis test with Tukey–Kramer post-hoc tests were used for comparison. A p <.05 was considered statistically significant. Results: The DSC significantly varied among different combos of images and different ADC thresholds. Hybrid U-Nets outperformed uniform U-Nets at ADC thresholds of 0.6 × 10^–3 mm²/s and 0.8 × 10^–3 mm²/s (p <.001). The U-Net with imaging combo of DDD had segmentation performance similar to hybrid U-Nets at an ADC threshold of 1.8 × 10^–3 mm²/s (p =.062 to 1). The U-Net using the imaging combo of DAA at the ADC threshold of 0.6 × 10^–3 mm²/s achieved the highest DSC in the segmentation of AIS lesion. Conclusions: The segmentation performance of U-Net for AIS varies among the input imaging combos and ADC thresholds. The U-Net is optimized by choosing the imaging combo of DAA at an ADC threshold of 0.6 × 10^–3 mm²/s in segmentating AIS lesion with highest DSC. Key Points: • Segmentation performance of U-Net for AIS differs among input imaging combos. • Segmentation performance of U-Net for AIS differs among ADC thresholds. • U-Net is optimized using DAA with ADC = 0.6 × 10^–3mm²/s. © 2023, The Author(s), under exclusive licence to European Society of Radiology.

关键词： Deep Learning Diffusion Magnetic Resonance Imaging Ischemic Stroke Neural Networks, Computer Retrospective Study

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Classification of the Structural Integrity by the General Vibration Method

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Procedia Computer Science 2019年 157卷 382-387页

作者： Fergyanto E. Gunawan Benfano Soewito Nico Surantha Tuga Mauritsius Nobumasa Sekishita Industrial Engineering Department BINUS Graduate Program - Master of Industrial Engineering Bina Nusantara University Jakarta Indonesia 11480 Computer Science Department BINUS Graduate Program - Master of Computer Science Bina Nusantara University Jakarta Indonesia 11480 Information Systems Information Department BINUS Graduate Program - Master of Information Systems Management Bina Nusantara University Jakarta Indonesia 11480 Department of Mechanical Engineering Toyohashi University of Technology Toyohashi Aichi 441-8580 Japan

Traditionally, for the purpose of classifying the integrity of an engineering structure, one may use the information of the natural frequencies or mode shapes or some other measures derived from the two. In this research, we propose a classification method on the basis of the general vibration model. The general vibration model is essentially a set of differential equations describing the dynamics of the structure under consideration. For the purpose of damage detection, a deviation of the general vibration model from the dynamic equilibrium point marks the occurrence of the damage. To demonstrate the effectiveness of the method, we study two simplest dynamical systems consisting of one- and two-concentrated masses subjected to a prescribed dynamic load. The structural damages are introduced artificially by reducing the stiffness of spring in the structures. We find that the general vibration model is more sensitive to damages than the traditional methods.

关键词： General Vibration Model Structural Integrity Structural Health Monitoring Power Spectral Density Damage Index

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A Study of the Sensitivity of the Fuel Consumption to Driving Strategy by Micro Simulation

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Procedia Computer Science 2019年 157卷 375-381页

Global warming due to excessive emission greenhouse gases is a significant issue faced by humanity, and collectively, cars and trucks contribute about 20% to the entire global-warming gases. For a reason, recently, many attempts have been endured to reduce the emission and to increase fuel efficiency, including vehicle platooning, better driving strategy, and increasing engine efficiency. This study intends to provide a more detail assessment regarding the effects of the driving strategy to fuel consumption. For the purpose, the vehicle dynamics are quantified by employing the car-following model based on the optimal velocity model. The fuel consumption is estimated from the regression model of Ahn 18 . The result suggests that the braking distance strongly affects fuel consumption.

关键词： Optimal Velocity Model Micro Simulation Car-Following Model Fuel Efficiency

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