Article
Optics
Rong Lin, Jidong Wu, Yiming Dong, Greg Gbur, Yangjian Cai, Jiayi Yu
Summary: The analysis of a class of conjugate mode partially coherent beams in a turbulent atmosphere shows that controlling the phase constant between modes can improve the shape of the beams and enhance turbulence resistance. These structured beams provide a new degree of freedom for shaping beams and have potential applications in free-space optical communications.
Article
Engineering, Electrical & Electronic
Andrea Cozza, Shao-Yin He, Yan-Zhao Xie
Summary: This paper explores how propagation and termination losses impact fault location techniques, discussing accuracy in terms of location uncertainty and systematic errors. It compares two location metrics, showing correlation to be unbiased and projection to be biased, due to different location mechanisms.
IEEE TRANSACTIONS ON POWER DELIVERY
(2021)
Article
Optics
Yalcin Ata, Olga Korotkova
Summary: The use of EMPCGs allows for fine spatial segregation in polarimetric components of stationary beams in atmospheric turbulence, with off-axis shifts remaining invariant with turbulence strength. This effect may enable novel techniques for direct energy, imaging, and wireless optical communication systems in turbulent air.
Article
Nanoscience & Nanotechnology
Heqing Huang, Adam C. Overvig, Yuan Xu, Stephanie C. Malek, Cheng-Chia Tsai, Andrea Alu, Nanfang Yu
Summary: Based on symmetry-breaking perturbations, leaky-wave metasurfaces offer pointwise control of the amplitude, phase and polarization of surface emission, which provides a universal generalization of grating couplers for integrated photonics. These metasurfaces integrate guided-wave photonic systems and enable full command over four optical degrees of freedom across large apertures, offering enhanced functionalities for controlling amplitude, phase, and polarization in light scattering. This hybrid approach merges guided and free-space optics, opening up applications in imaging, communications, augmented reality, quantum optics, LIDAR, and integrated photonic systems.
NATURE NANOTECHNOLOGY
(2023)
Article
Engineering, Civil
Ling Wan, Xiongyao Xie, Lujun Wang, Pan Li, Hua Yin
Summary: Disease in the liner back cavities of operational metro tunnels is influenced by various factors, characterized by high levels of hiddenness and uncertainty, and easily induces other tunnel diseases. This study proposes a novel cavity-locating method using perturbation theory and a modal strain energy cavity indicator to accurately locate single and multiple cavities in shield tunnels.
KSCE JOURNAL OF CIVIL ENGINEERING
(2021)
Article
Optics
Bo Shen, Bing Gu, Yueqiu Hu, Xiaohe Zhang, Guanghao Rui, Jun He, Yiping Cui
Summary: This paper introduces a double-mode concentric annular fractional vector beam, and the results show that fractional topological coefficients have a high degree of freedom, emphasizing the important connection between fractional coefficients and SAM density through experimental results.
OPTICS COMMUNICATIONS
(2022)
Article
Construction & Building Technology
Sertac Tuhta
Summary: This study investigated the possibility of using recorded micro tremor data as input for Experimental Modal Analysis (EMA) on a bench-scale earthquake simulator for a model wind tunnel. The study evaluated the dynamic characteristics of the model wind tunnel through analytical and experimental modal analysis. The research found a good correlation between mode shapes and an average difference of only 2.5% between natural frequencies and analytical frequencies.
WIND AND STRUCTURES
(2021)
Article
Chemistry, Multidisciplinary
Khondker Shihabul Hoque, Ahmed Zubair
Summary: This study investigates the possibility of inducing magnetization in tungsten selenide monolayer by alloying with vanadium selenide. The results show that as the proportion of vanadium atoms in the alloys increases, a phase transition from semiconducting to metallic to semiconducting is discovered, and all alloy compositions demonstrate induced magnetism with a long-range ferromagnetic order.
Article
Chemistry, Multidisciplinary
Yong Wang, Zihui Zhang, Long Guo, Yuxuan Chen, Yahui Li, Zhanbin Qi, Jianwei Ben, Xiaojuan Sun, Dabing Li
Summary: This study focused on modeling AlGaN-based deep-ultraviolet (DUV) LEDs with AlGaN as dielectric layers in polarization tunnel junctions (PTJs). It was found that using Al0.7Ga0.3N as the dielectric layer can increase hole concentration and radiative recombination rate in MQWs, but also leads to higher forward voltage requiring greater bias to enhance hole tunneling efficiency in the PTJ. By adopting this approach, enhanced internal quantum efficiency (IQE) and optical output power can be achieved.
Article
Astronomy & Astrophysics
Hassan Manshouri, Ahmad Hoseinpour, Moslem Zarei
Summary: The study focuses on using quantum Boltzmann equation to investigate the density matrix evolution of a system of nucleons, showcasing the advantages of utilizing quantum field theory tools. The equation involves forward scattering and collision terms, providing insights into the behavior of nucleon system in various magnetic fields. By considering nucleon-nucleon scattering, longitudinal and transverse relaxation times are derived from the collision term.
Article
Engineering, Civil
Ling Wan, Xiongyao Xie, Lujun Wang, Pan Li, Qiang Huang
Summary: Modal parameters play an important role in civil engineering, providing a characterization of structure properties and applications in vibration control and structural health monitoring. This study focuses on the analysis of mutual coupling tunnel and shield tunnels, which are complex and popular research topics in the field. By studying the shield tunnel of Shanghai metro line No.12 project, the authors present methods for identifying structural modal parameters and achieve accurate results.
Article
Multidisciplinary Sciences
Nika Haghtalab, Matthew O. Jackson, Ariel D. Procaccia
Summary: The two models of belief formation suggest that even with almost identical sources of information, polarized beliefs can still arise. In one model, people form deterministic functions that fit their past data best, while in the other model, individuals pay a cost based on the complexity of the belief function, leading to disagreements even with large training sets drawn from the same distribution.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Physics, Applied
Antonin Coutant, Vassos Achilleos, Olivier Richoux, Georgios Theocharis, Vincent Pagneux
Summary: This study investigates the acoustic analog of the two-dimensional Su-Schrieffer-Heeger model, revealing the behavior of topological edge waves and their scattering on edge structure changes. It is shown that edge waves exhibit perfect reflection at specific changes such as corners, leading to a new way of constructing corner modes. The high reflectivity applies to a broad class of edge changes, such as steps or defects, and results in localized edge modes isolated from their surroundings in finite networks.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Y. Zaoui, K. O. Obodo, L. Beldi, B. Bouhafs
Summary: Density functional theory was used to calculate the properties of Fe/MgO/Fe (001) magnetic tunnel junctions, highlighting the significant effects of interfacial oxygen atoms on the structural, magnetic, and electronic behavior of the system. The Fe/MgO/Fe structure exhibited metallic behavior with a Fe-O interface layer, and the polarization was found to be highly sensitive to the nature of the interface layer.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Optics
Juan Carlos Gonzalez de Sande, Gemma Piquero, Juan Carlos Suarez-Bermejo, Massimo Santarsiero
Summary: The study focuses on a class of nonuniformly totally polarized beams that maintain their transverse polarization pattern during propagation, which is of interest for certain polarimetric techniques. These beams allow for testing multiple polarization states of a sample simultaneously and do not require the use of imaging/magnifying optical systems.
Article
Computer Science, Artificial Intelligence
David Griol, Zoraida Callejas, Jose Manuel Molina, Araceli Sanchis
Summary: Conversational systems have become indispensable for billions of users, and designing the dialogue model is one of the most complex tasks in system development. Rule-based systems struggle to adapt to phenomena not considered during design.
Article
Computer Science, Artificial Intelligence
Lukas Mateju, David Griol, Zoraida Callejas, Jose Manuel Molina, Araceli Sanchis
Summary: This paper evaluates different configurations of deep-learned dialog management using three dialog corpora from different application domains, identifying key factors that can impact accuracy in the results.
Article
Computer Science, Artificial Intelligence
Daniel Gonzalez, Miguel A. Patricio, Antonio Berlanga, Jose M. Molina
Summary: According to the World Health Organization, the global population over 60 is expected to double by 2050, with a majority preferring to live alone. It is important to find mechanisms and tools, such as smart home systems, to help improve their autonomy.
Article
Engineering, Electrical & Electronic
Marwan Yusuf, Emmeric Tanghe, Frederic Challita, Pierre Laly, Luc Martens, Davy P. Gaillot, Martine Lienard, Wout Joseph
Summary: This study proposes a framework for long-term vehicular channel simulation based on the VTFAR model, which provides a sparse parametric description of nonstationary multivariate random processes. By using measurements from vehicle-to-infrastructure tunnels, the VTFAR model parameters are estimated and the model is validated by comparing the parametric and non-parametric spectra of the measured channel. The experimental results show a good agreement, with a low RMSE for delay spread and stationarity time.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Leandro Juan-Llacer, David Parraga Riquelme, Jose-Maria Molina-Garcia-Pardo, Jose-Victor Rodriguez, Maria-Teresa Martinez-Ingles, Juan Pascual-Garcia
Summary: Agriculture 4.0 brings increased sensor usage and new wireless technologies for efficient communication systems in agricultural environments. This study proposes a simplified model for estimating path loss in citrus plantations and compares the model's estimates with actual measurements. The results show a close match between the model and measurements.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2022)
Article
Chemistry, Analytical
Concepcion Sanchis-Borras, Maria-Teresa Martinez-Ingles, Jose-Maria Molina-Garcia-Pardo
Summary: The 5GPPP has published a white paper on 5G indoor services, focusing on the performance of mMIMO and mmWave systems in indoor environments. The study shows that utilizing SFBC and HBF algorithms can improve the throughput and communication distance of the system.
Article
Chemistry, Analytical
Nor El Islam Dahmouni, Pierre Laly, Marwan Yusuf, Gauthier Delbarre, Martine Lienard, Eric P. Simon, Davy P. Gaillot
Summary: Massive multiple-input multiple-output (mMIMO) communication systems are essential for 5G, but the current wireless radio channel models may not work well in dynamic scenarios. This study measured time-varying single-user mMIMO radio channels and found a strong correlation between the spatial distribution of the stationarity time and the scattering properties.
Article
Engineering, Civil
Juan Pascual-Garcia, Lorenzo Rubio, Vicent M. Rodrigo Penarrocha, Leandro Juan-Llacer, Jose-Maria Molina-Garcia-Pardo, Concepcion Sanchis-Borras, Juan Reig
Summary: Metro and railway systems are widely used for transportation, but access to high throughput wireless services inside wagons is limited. This study thoroughly analyzes the wireless channel in an intra-wagon environment using simulations and ray-tracing tools, providing insights for the deployment of efficient and high throughput networks.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2022)
Article
Chemistry, Analytical
Mohammed Mallik, Angesom Ataklity Tesfay, Benjamin Allaert, Redha Kassi, Esteban Egea-Lopez, Jose-Maria Molina-Garcia-Pardo, Joe Wiart, Davy P. Gaillot, Laurent Clavier
Summary: This study proposes a conditional generative adversarial network to accurately reconstruct the electromagnetic field exposure map in an outdoor urban environment. By learning the topology of the environment, the model is able to estimate the propagation characteristics of the electromagnetic field, and the results show that it outperforms traditional kriging methods in terms of accuracy.
Article
Engineering, Electrical & Electronic
Mohamad Ghaddar, Jose-Maria Molina-Garcia-Pardo, Ismail Ben Mabrouk, Martine Lienard, Pierre Degauque
Summary: Limited previous work has been done on deterministic modeling of 5G millimeter-wave wireless communications in nonuniform tunnels. This study predicts and analyzes broadband MIMO propagation in underground mine tunnels for 5G and beyond. The tunnel surfaces are modeled as diffracting rectangular prism wedges, and a deterministic RT MIMO model based on UTD is developed. The predicted MIMO subchannels are successfully fitted with experimental measurements, and the MIMO multipath fading in underground tunnels is found to be lognormally distributed and dependent on tunnel size and shape.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Chemistry, Analytical
Ricardo Robles-Enciso, Isabel Pilar Morales-Aragon, Alfredo Serna-Sabater, Maria Teresa Martinez-Ingles, Antonio Mateo-Aroca, Jose-Maria Molina-Garcia-Pardo, Leandro Juan-Llacer
Summary: In this research, power and quality measurements of four transmissions using different emission technologies were conducted in an indoor environment at the frequency of 868 MHz under two non-line-of-sight (NLOS) conditions. The received power of a narrowband continuous wave (CW) signal, as well as the Received Signal Strength Indicator (RSSI) and bit error rate (BER) of LoRa and Zigbee signals, were measured. Quality parameters of a 20 MHz bandwidth 5G QPSK signal were also measured. Two fitting models, the Close-in (CI) model and the Floating-Intercept (FI) model, were used to analyze the path loss. The results revealed different slopes for the NLOS-1 and NLOS-2 zones, and the FI model achieved the best accuracy in both NLOS situations.
Article
Computer Science, Information Systems
Jose-Victor Rodriguez, Maria-Teresa Martinez-Ingles, Jose-Maria Molina Garcia-Pardo, Leandro Juan-Llacer, Ignacio Rodriguez-Rodriguez
Summary: This paper presents two uniform theories of diffraction-physical optics (UTD-PO) formulations to analyze radiowave multiple diffraction in vegetated urban areas with both buildings and trees. The solutions consider buildings modeled as knife-edges and rectangular sections, and the effect of tree canopy is taken into account by adding proper attenuation factors/phasors. The validation of these formulations has been done through comparisons and measurements on a scaled-model. The advantage of the solutions is that they only include single diffractions, avoiding higher-order diffraction terms and reducing computational requirements.
Proceedings Paper
Engineering, Electrical & Electronic
Leandro Juan-Llacer, Jose Maria Molina-Garcia-Pardo, Alain Sibille, Saul A. Torrico, Luis Martinez Rubiola, Maria Teresa Martinez-Ingles, Jose-Victor Rodriguez, Juan Pascual-Garcia
Summary: This study analyzes the path loss of wireless communication systems in agriculture using different frequency bands. The results indicate the need to consider the multiple-scattering contributions from trees and the observed guiding effect.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
Proceedings Paper
Computer Science, Artificial Intelligence
Daniel Amigo, David Sanchez Pedroche, Jesus Garcia, Jose M. Molina
Summary: Geographic Information Systems (GIS) allow analysis based on geo-referenced data. This study aims to develop an automatic framework for extracting geo-referenced trees by merging different data sources and has achieved satisfactory results.
16TH INTERNATIONAL CONFERENCE ON SOFT COMPUTING MODELS IN INDUSTRIAL AND ENVIRONMENTAL APPLICATIONS (SOCO 2021)
(2022)
Proceedings Paper
Computer Science, Artificial Intelligence
Juan Pedro Llerena, Jesus Garcia, Jose Manuel Molina
Summary: Ship type identification in maritime context is crucial for authorities to control activities. This paper proposes a deep learning approach for binary classification to identify fishing ships, showing better performance compared to traditional machine learning methods and balancing techniques.
16TH INTERNATIONAL CONFERENCE ON SOFT COMPUTING MODELS IN INDUSTRIAL AND ENVIRONMENTAL APPLICATIONS (SOCO 2021)
(2022)
