المؤلفون: Florian Faucher (Faculty of Mathematics, University of Vienna), Otmar Scherzer (Faculty of Mathematics, University of Vienna)

المصدر: Data in Brief ; issn:2352-3409

مصطلحات موضوعية: Inverse problems, Visco-acoustic models, Time-harmonic wave propagation, Full waveform inversion

الوصف: The abstract is available here: https://uscholar.univie.ac.at/o:2008538Test ; The abstract is available here: https://uscholar.univie.ac.at/o:2008538Test

وصف الملف: application/pdf

العلاقة: hdl:11353/10.2008538; https://phaidra.univie.ac.at/o:2008538Test

الإتاحة: https://doi.org/10.1016/j.dib.2023.109199Test
https://phaidra.univie.ac.at/o:2008538Test

المؤلفون: Chao Xu, Zexing Yu, Fei Du, Jiaying Sun

المصدر: Chinese Journal of Aeronautics. 35:208-221

مصطلحات موضوعية: Physics, Guided wave testing, Fuselage, Wave propagation, Scattering, Mechanical Engineering, Acoustics, Aerospace Engineering, Sensitivity (control systems), Time domain, Interference (wave propagation), Finite element method

الوصف: Stiffened panels have been widely utilized in fuselages and wings as critical load-bearing components. These structures are prone to be damaged under long-term and extreme loads, and their health monitoring has been a common concern. The guided wave-based monitoring method is regarded as an efficient approach to detect the damage in stiffened plates because of its wide monitoring range and high sensitivity to micro-damage. Efficient simulation of wave propagation can theoretically demonstrate the detection mechanism of the method. In this study, a Time-Domain Spectral Finite Element Method (TD-SFEM) is adopted to study the wavefield in stiffened plates, where continuous Absorbing Layers with Increasing Damping (ALID) strategy is proposed to circumvent the disturbance of reflected waves on boundaries. After the convergence analysis, the developed TD-SFEM with ALID is validated by the finite element method first. Then, wave scattering and the influence of the stiffener are investigated in detail by comparing the results with the non-stiffened structure. Finally, the effects of the parameters of the stiffener, such as the height and width, on wave propagation are studied, respectively. The results illustrate that the proposed TD-SFEM with ALID is an efficient approach to study the wave propagation in the stiffened plate and can reveal the mechanism of influence of the stiffener. It is found that the height of the stiffener changes the interference of wavefield in the plate, while the effects of the width are mainly in wave scattering and mode conversion.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::9080aa0f944dab8132d91f29a43525bfTest
https://doi.org/10.1016/j.cja.2021.11.014Test

المؤلفون: B.P. Vijay Kumar, Syed Musthak Ahmed, Mahendhra Nanjappa Giri Prasad

المصدر: Materials Today: Proceedings. 80:1747-1750

مصطلحات موضوعية: Computational model, Hidden node problem, business.industry, Computer science, Quality of service, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, Throughput, General Medicine, Interference (wave propagation), Multipath routing, Routing (electronic design automation), business, Wireless sensor network, Computer network

الوصف: The proposed approach is designed to boost the IEEE 802.15.4 / ZigBee-based WSN streaming efficiency by introducing multipurpose routing. We investigate how those networks can be designed in order to achieve optimum throughput using computational models to explain intra-track and inter-track interference in multipath routing networks. One mode of action in particular – Spatial-TDMA (S-TDMA), Zig Bee dependent WSNs, will greatly reduce the amount of interference, both in one- and multi-track environments. It is also seen that two-way networks can be stronger than their one-way counterparts by means of deliberately selected implementation parameters. Finally, a greater degree of spatial isolation between the routes used indicates improved average efficiency in multi-path scenarios. The simulation is one of our results.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::4cb458e080e349d99800fff9df66b331Test
https://doi.org/10.1016/j.matpr.2021.05.498Test

المؤلفون: Bang Chul Jung, Yongjae Kim, Janghyuk Youn

المصدر: ICT Express. 8:485-489

مصطلحات موضوعية: Scheme (programming language), Computational complexity theory, Computer Networks and Communications, business.industry, Computer science, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, Interference (wave propagation), Power (physics), Artificial Intelligence, Hardware and Architecture, Telecommunications link, Electronic engineering, Wireless, Antenna (radio), business, computer, Software, Energy (signal processing), Computer Science::Information Theory, Information Systems, computer.programming_language

الوصف: We propose a novel interference alignment (IA) technique with receive antenna partitioning (RAP) for simultaneous wireless information and power transfer (SWIPT)-enabled downlink fog radio access networks (F-RANs). The basic idea of the proposed scheme is to apply a generalized downlink IA for each access point (AP) and to divide receive antennas at each user into two groups for information decoding (ID) and energy harvesting (EH), respectively. With the proposed scheme, an optimal receive antenna configuration at each user is obtained to maximize the weighted sum of achievable rate and the sum of harvested energy of the network. Also we develop an antenna configuration selection algorithm to obtain near-optimal performance with low computational complexity. Through extensive computer simulations, it is shown that the proposed scheme significantly improves a rate-energy region compared with existing techniques.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::bcfebad691e0f1c19b64451e9537a34cTest
https://doi.org/10.1016/j.icte.2021.09.011Test

المؤلفون: Lijun Yang, Jing Liu, Longfei Xiao, Yufeng Kou, Jun Li

المصدر: Journal of Ocean Engineering and Science. 7:419-430

مصطلحات موضوعية: Physics, Nonlinear system, Environmental Engineering, Series (mathematics), Acoustics, Offshore geotechnical engineering, Fast Fourier transform, Ocean Engineering, Low frequency, Oceanography, Interference (wave propagation), Hilbert–Huang transform, Square (algebra)

الوصف: Wave run-up on surface-piercing columns is an important phenomenon in offshore engineering. Previous studies have mainly focused on a single column and circular column arrays. This study is concerned with the wave run-up ratio and the wave force on a fixed array of four rounded square columns. A series of regular wave tests were conducted, and the effects of wave periods and steepness were investigated. The nonlinearity of the wave run-up under incident waves with a small period is more sensitive to wave steepness. Utilizing empirical mode decomposition (EMD) and fast Fourier transform (FFT) methods, the measured signals were separated into three components representing characteristics of the incident wave component (IMF1), near-field interference (IMF2), and far-field low frequency reflected wave (IMF3), respectively. The proposed methods are helpful for studying the mechanism of near-field interference, and the experimental data are essential benchmarks for validating further numerical simulations of wave run-ups on rounded square columns.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::97e7a1e998d7020817cd5a4c487524c8Test
https://doi.org/10.1016/j.joes.2021.09.016Test

المؤلفون: Jun Huang, Yong Ma, Xiaoguang Mei, Zhao-bing Qiu, Fan Fan, Minghui Wu

المصدر: Defence Technology. 18:1589-1601

مصطلحات موضوعية: Pixel, business.industry, Computer science, Mechanical Engineering, media_common.quotation_subject, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Metals and Alloys, Computational Mechanics, Pattern recognition, Interference (wave propagation), Measure (mathematics), Constant false alarm rate, Random walker algorithm, Sliding window protocol, Ceramics and Composites, Contrast (vision), Segmentation, Artificial intelligence, business, media_common

الوصف: Infrared (IR) small target detection is one of the key technologies of infrared search and track (IRST) systems. Existing methods have some limitations in detection performance, especially when the target size is irregular or the background is complex. In this paper, we propose a pixel-level local contrast measure (PLLCM), which can subdivide small targets and backgrounds at pixel level simultaneously. With pixel-level segmentation, the difference between the target and the background becomes more obvious, which helps to improve the detection performance. First, we design a multiscale sliding window to quickly extract candidate target pixels. Then, a local window based on random walker (RW) is designed for pixel-level target segmentation. After that, PLLCM incorporating probability weights and scale constraints is proposed to accurately measure local contrast and suppress various types of background interference. Finally, an adaptive threshold operation is applied to separate the target from the PLLCM enhanced map. Experimental results show that the proposed method has a higher detection rate and a lower false alarm rate than the baseline algorithms, while achieving a high speed.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::fb6038f4da19a7e2489ce93f721a4af0Test
https://doi.org/10.1016/j.dt.2021.07.002Test

المؤلفون: M. Asif, Mohammad Mirzazadeh, Kamyar Hosseini, Lanre Akinyemi, M. Raheel, Asim Zafar

المصدر: Journal of Ocean Engineering and Science. 7:337-344

مصطلحات موضوعية: Environmental Engineering, Current (mathematics), Wave propagation, Ocean Engineering, Conformable matrix, Type (model theory), Oceanography, Differential operator, Nonlinear system, symbols.namesake, Nonlinear Sciences::Exactly Solvable and Integrable Systems, symbols, Applied mathematics, Soliton, Nonlinear Sciences::Pattern Formation and Solitons, Schrödinger's cat, Mathematics

الوصف: The current study deals with exact soliton solutions for Schrodinger-Hirota (SH) equation via two modified integration methods. Those methods are known as the improved ( G ′ / G ) -expansion method and the Kudryashov method. This model is a generalized version of the nonlinear Schrodinger (NLS) equation with higher order dispersion and cubic nonlinearity. It can be considered as a more accurate approximation than the NLS equation in explaining wave propagation in the ocean and optical fibers. A novel derivative operator named as the conformable truncated M-fractional is used to study the above mentioned model. The obtained results can be used in describing the Schrodinger-Hirota equation in some better way. Moreover the obtained results are verified through symbolic computational software. Also, the obtained results show that the suggested approaches have broaden capacity to secure some new soliton type solutions for the fractional differential equations in an effective way. In the end, the results are also explained through their graphical representations.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::90b0d3df0ab43cf66d3fdeae49034f92Test
https://doi.org/10.1016/j.joes.2021.09.007Test

المؤلفون: Bingyan Chen, Fengshou Gu, Weihua Zhang, Yao Cheng, Guiming Mei

المصدر: ISA Transactions. 127:395-414

مصطلحات موضوعية: Bearing (mechanical), Frequency band, Computer science, business.industry, Applied Mathematics, Spectrum (functional analysis), Pattern recognition, Fault (power engineering), Interference (wave propagation), Radio spectrum, Computer Science Applications, law.invention, Control and Systems Engineering, Feature (computer vision), law, Artificial intelligence, Electrical and Electronic Engineering, Envelope (radar), business, Instrumentation

الوصف: Identifying a spectral frequency band with abundant fault information from spectral coherence is essential for improved envelope spectrum-based bearing diagnosis. Both blind features and targeted features have been employed to distinguish informative spectral frequency band of spectral coherence. However, how to select appropriate feature to correctly discriminate the optimal frequency band of spectral coherence in different scenarios is problematic. In this study, a new targeted feature is presented to quantify the signal-to-noise ratio in narrow frequency bands of spectral coherence, and further a method based on the proposed feature is developed to distinguish an optimal spectral frequency band of spectral coherence for bearing diagnostics. The efficiency of the developed method, typical blind feature-based methods and typical targeted feature-based methods in identifying the defect-sensitive frequency band of spectral coherence and bearing fault diagnosis is validated and compared using simulated signals with different interference noises and bearing experimental signals. The advantages and limitations of typical blind and targeted feature-based methods in different scenarios are summarized to guide the application. The results demonstrate that the developed targeted feature can efficiently evaluate bearing failure information in the cyclic frequency domain, and the presented approach can accurately discriminate the failure-related spectral frequency band of spectral coherence and detect different bearing faults compared with the methods based on the state-of-the-art features.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::39b782f865b9dd60bb13d6cfb4c792b6Test
https://doi.org/10.1016/j.isatra.2021.08.025Test

المؤلفون: Hino, Naoya, Rossetti, Leone, Marín-Llauradó, Ariadna, Aoki, Kazuhiro, Trepat, Xavier, Matsuda, Michiyuki, Hirashima, Tsuyoshi

المساهمون: 日野, 直也, 青木, 一洋, 松田, 道行, 平島, 剛志, 80881531, 10620198

مصطلحات موضوعية: collective cell migration, ERK/MAPK, EGFR, FRET, front-rear polarity, intercellular signal transfer, mathematical model, mechanochemical feedback, mechanotransduction, wave propagation

الوصف: 分子活性の波が細胞集団に伝わる制御機構を解明 --細胞同士の綱引きが情報を遠くに伝える--. 京都大学プレスリリース. 2020-06-04. ; Cells communicate by doing the 'wave'. 京都大学プレスリリース. 2020-07-22. ; During collective migration of epithelial cells, the migration direction is aligned over a tissue-scale expanse. Although the collective cell migration is known to be directed by mechanical forces transmitted via cell-cell junctions, it remains elusive how the intercellular force transmission is coordinated with intracellular biochemical signaling to achieve collective movements. Here, we show that intercellular coupling of extracellular signal-regulated kinase (ERK)-mediated mechanochemical feedback yields long-distance transmission of guidance cues. Mechanical stretch activates ERK through epidermal growth factor receptor (EGFR) activation, and ERK activation triggers cell contraction. The contraction of the activated cell pulls neighboring cells, evoking another round of ERK activation and contraction in the neighbors. Furthermore, anisotropic contraction based on front-rear polarization guarantees unidirectional propagation of ERK activation, and in turn, the ERK activation waves direct multicellular alignment of the polarity, leading to long-range ordered migration. Our findings reveal that mechanical forces mediate intercellular signaling underlying sustained transmission of guidance cues for collective cell migration.

وصف الملف: application/pdf

العلاقة: https://www.kyoto-u.ac.jp/ja/research-news/2020-06-04Test; http://hdl.handle.net/2433/253559Test; Developmental Cell; 53; 646; 660.e8

الإتاحة: http://hdl.handle.net/2433/253559Test

المؤلفون: Mehrullah Mehr, Davood Rostamy

المصدر: Alexandria Engineering Journal, Vol 61, Iss 6, Pp 4445-4455 (2022)

مصطلحات موضوعية: Eikonal equation, General Engineering, Engineering (General). Civil engineering (General), Grid, Stability (probability), Fourier differential quadrature, ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, Convergence (routing), Nyström method, Applied mathematics, Wave Propagation, TA1-2040, Polynomial differential quadrature, Differential (mathematics), Mathematics

الوصف: This article presents an efficient method to solve of Eikonal equation by the new differential quadrature method. The purpose of this article is to obtain the accuracy and performance method for the Eikonal equation. We introduce a novel grid points to reduce errors and compared them on different issues to accelerate convergence. The accuracy and stability of numerical results for two and three-dimensional of the Eikonal equation are presented. In these numerical examples, we investigate the stability of the proposed method by adding random noises. The new differential quadrature method is a capable method for the some numerical examples and we evaluate the accuracy and performance of our proposed method.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::940455ddfcd5d010d9f98eebb5527d82Test
https://doi.org/10.1016/j.aej.2021.10.003Test