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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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Chronic kidney disease and the use of social media as strategy for health education in Brazil 17

Chronic kidney disease and the use of social media as strate...

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17th World Congress on Medical and Health Informatics, MEDINFO 2019

作者： De Oliveira, Juliana Gomes Ramalho Askari, Marjan Fahd, Marília Girão Nobre Pereira, Gabriel Araújo Da Silva, Aglalberto Lourenço Filho, José Eurico Vasconcelos Jardim, Maria Helena de Agrela Gonçalves Da Silva, Geraldo Bezerra Public Health Graduate Program Health Sciences Center University of Fortaleza. Fortaleza Ceará Brazil Erasmus School of Health Policy and Management Health Services Management and Organization Erasmus University Rotterdam Netherlands School of Medicine University of Fortaleza Fortaleza Ceará Brazil Laboratory of Innovation in Information Technology Technology Sciences Center University of Fortaleza. Fortaleza Ceará Brazil Health School Universidade da Madeira Funchal Região Autônoma da Madeira Portugal School of Medicine Public Health Graduate Program Health Sciences Center University of Fortaleza. Fortaleza Ceará Brazil

ISBN: (纸本)9781643680026

Chronic kidney disease (CKD) is a Public Health problem worldwide. Treatment in complex and depends on patient education to achieve adequate adherence. We describe in this paper novel strategies for patients' education based on internet (youtube and instagram), through videos, images and texts information directed for patients in a project developed in Brazil. © 2019 International Medical Informatics Association (IMIA) and IOS Press.

关键词： Medical informatics

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Factors of Web Design, Application Design and Service Quality on Satisfaction of E-Billing Users in Indonesia 6

Factors of Web Design, Application Design and Service Qualit...

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6th International Conference on Orange Technologies, ICOT 2018

作者： Zulita, Leni Natalia Abiyyu, Fawwaz K. Bachtiar, Sariful Susena, Karona Cahya Sfenrianto, Sfenrianto Kaburuan, Emil R. Department of Information Technology Dehasen University Bengkulu Indonesia Information Systems Management Department Bina Nusantara University BINUS Graduate Program-Master of Information Systems Management Jakarta11480 Indonesia Department of Management Dehasen University Bengkulu Indonesia

ISBN: (纸本)9781538673195

with the development of digital technology online payments can be made for various purposes. At present, the Indonesian tax directorate general has implemented an E-billing system that can be used by the public to make tax payments online. E-billing is available in the form of web-based and mobile applications in order to facilitate the public in making payments. However, in reality, there are still many people who prefer to use traditional methods of paying taxes. Initial allegations, these problems relate to web design factors, design applications, and website quality from the E-billing system. This paper examines the factors that relate to people's satisfaction with the decision to use the E-billing system. © 2018 IEEE.

关键词： Web Design

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Application of Message Security Application Using Vigenere Cipher Algorithm Utilizing One Time Pad (OTP) Algorithm as a Key Generator 1

Application of Message Security Application Using Vigenere C...

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1st Workshop on Environmental Science, Society, and technology, WESTECH 2018

作者： Pardede, A.M.H. Br Sitepu, Lorena Perbina Zarlis, Muhammad Tulus Iskandar, Akbar Sriadhi, S. Manurung, Rosida Tiurma Siregar, Nurintan Asyiah Sari, Ayu Esteka Yunawati, Sri Mursyidah, M. Mursalin, M. Kurniasih, Nuning Kurniawan, Citra Winarno, Edy STMIK Kaputama Sumatera Utara Binjai Indonesia Department of Computer Science Universitas Sumatera Utara Medan Indonesia Department of Mathematics Universitas Sumatera Utara Medan Indonesia Department of Electrical Engineering Universitas Negeri Medan Indonesia Graduate Program in Scientific Psychology Universitas Kristen Maranatha Indonesia Department of Management STIE Labuhanbatu Sumatera Utara Indonesia Department of Management STIE Sakti Alam Kerinci Jambi Indonesia Program Study of Accounting Pasir Pengaraian University Riau Indonesia Departement of Information Technology and Computer Politeknik Negeri Lhokseumawe Aceh Indonesia Department of Mathematics Education Universitas Malikussaleh Aceh Indonesia Faculty of Communication Sciences Library and Information Science Program Universitas Padjadjaran Bandung Indonesia Department of Electrical Engineering Sekolah Tinggi Teknik Malang Indonesia Faculty of Information Technology Universitas Stikubank Semarang Indonesia

Cryptography is the science and art of maintaining the security of messages when messages are sent from one place to another. One of the ways securing the form of text message information is by the encryption process using the Vigenere Cipher algorithm and utilizing the One Time Pad (OTP) algorithm as a key generator, where the message will be random when it is opened. The message encryption process used the vigenere cipher algorithm while OTP is used to secure the key with the same formula. After this research has been done, an application was designed to secure text messages by converting the text message into a random message so that the message was unreadable due to a secret message that could not be known by others. The results achieved can secure an encrypted message that cannot be reopened and if those messages were reopened, they must be decrypted. © Published under licence by IOP Publishing Ltd.

关键词： Cryptography

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Integrating teaching, research and problem solving: An experience in progress at Mucuri Valley region (Brazil) 21

Integrating teaching, research and problem solving: An exper...

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21st World Multi-Conference on Systemics, Cybernetics and Informatics, WMSCI 2017

作者： Barroso, Leônidas Graduate Program in Information Systems and Knowledge Management Universidade FUMEC Belo Horizonte Brazil

ISBN: (纸本)9781941763599

This short article describes an interdisciplinary project that seeks to integrate teaching, research and real life problem solving. It concerns to the question: how to achieve development respecting the natural resources of the Mucuri Valley region in the states of Minas Gerais and Bahia, Brazil. Using geographic information as a guiding axis, the technological support for interdisciplinary dialogues is provided by Geographic information Systems, integrating data, information, techniques, methods and people from different fields of knowledge. © by the International Institute of Informatics and Systemics.

关键词： Geographic information systems

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