Article
Optics
Christos Karapanagiotis, Konstantin Hicke, Aleksander Wosniok, Katerina Krebber
Summary: In this paper, we report the first distributed relative humidity sensing in silica polyimide-coated optical fibers using Brillouin optical frequency domain analysis (BOFDA). The linear regression algorithm, a simple and well-interpretable machine learning and statistics method, is employed with the Brillouin frequency shifts and linewidths of the fiber's multipeak Brillouin spectrum as features. Machine learning concepts are utilized to estimate the model's uncertainties and select the most influential features to improve the regression algorithm's effectiveness. The model can also provide distributed temperature estimation simultaneously, addressing the cross-sensitivity effects.
Article
Chemistry, Analytical
Qiang Huang, Junqiang Sun, Wenting Jiao, Li Kai
Summary: This study proposes a simplified partitioned Brillouin gain spectrum (BGS) analysis method to improve the spatial resolution and measurement accuracy of a Brillouin optical time-domain reflectometer (BOTDR) with the assistance of a first-order Raman pump. The authors derive a mathematical model of the partitioned BGS and analyze the superposition process of sub-Brillouin signals within a theoretical spatial resolution range. By unifying unknown constant parameters, the authors simplify the analysis method and determine the uniform parameter through system test data and numerical analysis. In addition, the study automates data processing and determines the starting point of temperature/strain change based on the first occurrence of maximum Brillouin frequency shift (BFS) to obtain the calculation starting position of the partitioned BGS analysis method. Experimental results show that using a 100 ns probe pulse and the partitioned BGS analysis method, a spatial resolution of 0.4 m is achieved in a 78.45-km-long Raman-assisted BOTDR system, significantly improving the measurement accuracy. Furthermore, a strain accuracy of 5.6 με and a spatial resolution of 0.4 m are achieved in a 28.5-km-long BOTDR system without Raman amplification.
Article
Optics
Haoting Wu, Nan Guo, Danqi Feng, Guolu Yin, Tao Zhu
Summary: In this study, the image deconvolution technique is proposed to improve the spatial resolution of Brillouin optical time domain reflectometry (BOTDR) systems. By treating the measured Brillouin gain spectrum (BGS) distribution as an image, the deconvolution algorithm is used to reduce the blurring effect and enhance the spatial resolution. The results show that the proposed technique can improve the sensing information of short fiber segments while maintaining other parameters.
Article
Engineering, Electrical & Electronic
Ahmed Sabri Kadhim Almoosa, Abdulwahhab Essa Hamzah, Mohd Saiful Dzulkefly Zan, Mohd Faisal Ibrahim, Norhana Arsad, Mohamed M. Elgaud
Summary: We propose using an artificial neural network (ANN) model to improve the Brillouin frequency shift (BFS) resolution of the differential cross-spectrum Brillouin optical time domain reflectometry (DCS-BOTDR) fiber sensor. The ANN model offers more flexibility in estimating BFS and significantly improves the resolution.
OPTICAL FIBER TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Anastasia Vrettou, Hiroto Kitaguchi, Biao Cai, Thomas Connolley, David M. Collins
Summary: This study investigates the effect of Strain Path Changes (SPCs) on the mechanical properties and crystal-level features of deformation in a single phase, ferritic steel. The results show that abrupt strain paths significantly reduce ductility, and the pre-strain direction has a major influence on the macroscopic response and texture configuration. Increasing pre-strain magnitudes result in a stagnation of lattice strain hardening rates and a significant increase in Geometrically Necessary Dislocation (GND) densities. There is no correlation found between GND density and grain orientation, indicating that the initial texture and texture developed in pre-strain play a decisive role in determining ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Optics
Xiaonv Wu, Hao Feng, Jiawei Li, Jingchuan Zhang, Zhou Sha
Summary: This paper conducts a comprehensive experimental investigation on the performance of sensing fiber in ultra-low temperature environment and draws some useful conclusions.
Article
Engineering, Electrical & Electronic
Osamu Furukawa
Summary: An analytical method is developed in this study to correct the erroneous peak determinations in Brillouin sensors caused by noise overlapping. This method is based on the nature of the spectral-intensity trends along with the distance axis. Simulations demonstrate that this method is effective in avoiding a large jump to a false peak.
IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Huan Zheng, Shijie Sun, Yali Qin, Feng Xiao, Chuanqi Dai
Summary: This paper proposes and experimentally demonstrates a method for extracting Brillouin frequency shifts from Brillouin gain spectrum in Brillouin distributed fiber sensors using K nearest neighbor algorithm. The study shows that the performance of Brillouin frequency shift extraction degrades with the increase of frequency scanning step and the decrease of signal-to-noise ratio. The result suggests that the K nearest neighbor algorithm is a better way to extract the Brillouin frequency shift from the Brillouin gain spectrum.
OPTICAL FIBER TECHNOLOGY
(2022)
Article
Engineering, Multidisciplinary
Xianghao Meng, Dongyu Zhang, Hui Li, Yong Huang
Summary: In this study, a novel two-stage strain/temperature measurement method based on Bayesian uncertainty quantification is proposed to improve the efficiency of BOTDA. The method utilizes transitional Markov chain Monte Carlo algorithm to guide the scanning of frequency points in the second stage, ensuring high confidence for Brillouin frequency identification. Experimental and numerical data are used to verify the effectiveness of the proposed method.
Article
Optics
Huan Chen, Tao Wang, Qian Zhang, Jingyang Liu, Jiaxin Peng, Xiaopeng Ge, Jianzhong Zhang, Mingjiang Zhang
Summary: We propose a method based on the BOTDA system to demodulate length changes in the heating region using probe light intensity. This method allows for recognition of small length changes under wide pulse width conditions. Theoretical analysis and experiments demonstrate an exponential relationship between probe light intensity and heating region length.
Article
Physics, Multidisciplinary
Xia-Xia Niu, Yi-Feng Yang, Zhao Quan, Chun-Lei Yu, Qin-Ling Zhou, Hui Shen, Bing He, Jun Zhou
Summary: The study explores the relationship between BGS characteristics and Ge concentration in Ge-doped fibers, showing that BFS is inversely proportional to GeO2 concentration, while BGS bandwidth initially increases and then decreases with GeO2 concentration. Experimental results confirm the simulation findings, indicating that increasing fiber diameter leads to a broader BGS bandwidth.
Article
Engineering, Electrical & Electronic
Di Wang, Xindong Zhang, Xueqing Zhao, Zhangyi Yang, Wei Dong
Summary: We propose and theoretically demonstrate a photonic-assisted frequency measurement system based on stimulated Brillouin scattering (SBS) with high accuracy, high resolution, and the capability of multiple frequencies estimation. The system achieves great performance by optimizing the gain spectrum and loss spectrum. It can obtain the frequency information of multiple unknown signals.
OPTICAL FIBER TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Sergey Tsvetkov, Maxim M. Khudyakov, Alexey S. Lobanov, Denis S. Lipatov, Mikhail M. Bubnov, Alexey N. Guryanov, Valery Temyanko, Mikhail E. Likhachev
Summary: A novel method of SBS gain suppression in passive single-mode optical fibers is proposed and experimentally verified, achieving approximately evenly distributed gain over a wide spectral range. By utilizing uneven complex doping of the core with two additives, up to 8 dB of SBS suppression was achieved, with the potential for more than 10 dB of gain suppression with optimal dopant distribution.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Bin Liu, Jianping He, Shihai Zhang, Yinping Zhang, Jianan Yu, Xiaoxue Wang
Summary: The article introduces a new algorithm to improve the extraction accuracy of Brillouin frequency shift in distributed optical fiber sensors, which can achieve better results in complex stress and optical fiber self-damage situations.
Article
Engineering, Manufacturing
Junhe Lian, Wenqi Liu, Xabier Gastanares, Rongfei Juan, Joseba Mendiguren
Summary: This study investigates the plasticity evolution of an aluminum-magnesium alloy under different stress states, including monotonic and non-monotonic loading. It is found that the alloy exhibits lower yield strength and higher stress at large strains during reloading, indicating a phenomenon known as permanent hardening. The comprehensive understanding of the non-monotonic behavior provided by this study can contribute to the development of material models and the understanding of underlying mechanisms.
INTERNATIONAL JOURNAL OF MATERIAL FORMING
(2022)
Article
Statistics & Probability
Roberto Cortez, Joaquin Fontbona
ANNALS OF APPLIED PROBABILITY
(2016)
Article
Statistics & Probability
J. Berestycki, M. C. Fittipaldi, J. Fontbona
PROBABILITY THEORY AND RELATED FIELDS
(2018)
Article
Physics, Mathematical
Roberto Cortez, Joaquin Fontbona
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2018)
Article
Statistics & Probability
Francois Bolley, Djalil Chafai, Joaquin Fontbona
ANNALS OF APPLIED PROBABILITY
(2018)
Article
Biology
Mireille Bossy, Joaquin Fontbona, Hector Olivero
JOURNAL OF MATHEMATICAL BIOLOGY
(2019)
Article
Statistics & Probability
D. Fekete, J. Fontbona, A. E. Kyprianou
JOURNAL OF APPLIED PROBABILITY
(2019)
Article
Geochemistry & Geophysics
Claire Delplancke, Joaquin Fontbona, Jorge Prado
Article
Statistics & Probability
Dorottya Fekete, Joaquin Fontbona, Andreas E. Kyprianou
JOURNAL OF APPLIED PROBABILITY
(2020)
Article
Engineering, Electrical & Electronic
Felipe Tobar, Felipe Bravo-Marquez, Jocelyn Dunstan, Joaquin Fontbona, Alejandro Maass, Daniel Remenik, Jorge F. Silva
Summary: At the Faculty of Physical and Mathematical Sciences at Universidad de Chile, an ecosystem has been developed for teaching data science to engineers, meeting the growing demand for DS qualifications in both academic and professional environments.
IEEE SIGNAL PROCESSING MAGAZINE
(2021)
Article
Statistics & Probability
Joaquin Fontbona, Felipe Munoz-Hernandez
Summary: This paper establishes an explicit rate of convergence for systems of mean-field interacting diffusions with logistic binary branching towards solutions of nonlinear evolution equations. The proof relies on a novel coupling argument for binary branching diffusions based on optimal transport, allowing accurate simulation of the trajectory of the interacting binary branching population. Our approach and results extend propagation of chaos techniques and ideas to stochastic systems of interacting branching populations.
ELECTRONIC JOURNAL OF PROBABILITY
(2022)
Article
Statistics & Probability
Julio Backhoff-Veraguas, Joaquin Fontbona, Gonzalo Rios, Felipe Tobar
Summary: This paper introduces and studies a novel model-selection strategy for Bayesian learning based on optimal transport. The paper presents the Bayesian Wasserstein barycenter (BWB) estimator and shows its advantages compared to other selection strategies. The paper also discusses the existence and statistical consistency of the BWB and demonstrates its computation using the stochastic gradient descent algorithm.
ESAIM-PROBABILITY AND STATISTICS
(2022)
Article
Operations Research & Management Science
D. Neira, G. Soto, J. Fontbona, J. Prado, S. Gaete
APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY
(2018)
Proceedings Paper
Automation & Control Systems
J. Fontbona, H. C. Ramirez, V. Riquelme, F. J. Silva
Article
Statistics & Probability
Joaquin Fontbona, Nathael Gozlan, Jean-Francois Jabir
ANNALES DE L INSTITUT HENRI POINCARE-PROBABILITES ET STATISTIQUES
(2017)
Article
Statistics & Probability
Joaquin Fontbona, Fabien Panloup
ANNALES DE L INSTITUT HENRI POINCARE-PROBABILITES ET STATISTIQUES
(2017)
Article
Engineering, Multidisciplinary
Sicheng Jiao, Shixiang Wang, Minge Gao, Min Xu
Summary: This paper presents a non-contact method of thickness measurement for thin-walled rotary shell parts based on a chromatic confocal sensor. The method involves using a flip method to obtain surface profiles from both sides of the workpiece, measuring the decentration and tilt errors of the workpiece using a centering system, establishing a unified reference coordinate system, reconstructing the external and internal surface profiles, and calculating the thickness. Experimental results show that the method can accurately measure the thickness of a sapphire spherical shell workpiece and is consistent with measurements of other materials.
Article
Engineering, Multidisciplinary
Rajeev Kumar, Sajal Agarwal, Sarika Pal, Alka Verma, Yogendra Kumar Prajapati
Summary: This study evaluated the performance of a CaF2-Ag-MXene-based surface plasmon resonance (SPR) sensor at different wavelengths. The results showed that the sensor achieved the maximum sensitivity at a wavelength of 532 nm, and higher sensitivities were obtained at shorter wavelengths at the expense of detection accuracy.
Article
Engineering, Multidisciplinary
Attilio Di Nisio, Gregorio Andria, Francesco Adamo, Daniel Lotano, Filippo Attivissimo
Summary: Capacitive sensing is a widely used technique for a variety of applications, including avionics. However, current industry standard Capacitive Level Sensors (CLSs) used in helicopters perform poorly in terms of sensitivity and dynamic characteristics. In this study, novel geometries were explored and three prototypes were built and tested. Experimental validation showed that the new design featuring a helicoidal slit along the external electrode of the cylindrical probe improved sensitivity, response time, and linearity.
Article
Engineering, Multidisciplinary
Kai Yang, Huiqin Wang, Ke Wang, Fengchen Chen
Summary: This paper proposes an effective measurement method for dynamic compaction construction based on time series model, which enables real-time monitoring and measurement of anomalies and important construction parameters through simulating motion state transformation and running time estimation.
Article
Engineering, Multidisciplinary
Hui Fu, Qinghua Song, Jixiang Gong, Liping Jiang, Zhanqiang Liu, Qiang Luan, Hongsheng Wang
Summary: An automatic detection and pixel-level quantification model based on joint Mask R-CNN and TransUNet is developed to accurately evaluate microcrack damage on the grinding surfaces of engineering ceramics. The model is effectively trained on actual micrograph image dataset using a joint training strategy. The proposed model achieves reliable automatic detection and fine segmentation of microcracks, and a skeleton-based quantification model is also proposed to provide comprehensive and precise measurements of microcrack size.
Review
Engineering, Multidisciplinary
Sang Yeob Kim, Da Yun Kwon, Arum Jang, Young K. Ju, Jong-Sub Lee, Seungkwan Hong
Summary: This paper reviews the categorization and applications of UAV sensors in forensic engineering, with a focus on geotechnical, structural, and water infrastructure fields. It discusses the advantages and disadvantages of sensors with different wavelengths and addresses the challenges of current UAV technology and recommendations for further research in forensic engineering.
Article
Engineering, Multidisciplinary
Anton Nunez-Seoane, Joaquin Martinez-Sanchez, Erik Rua, Pedro Arias
Summary: This article compares the use of Mobile Laser Scanners (MLS) and Aerial Laser Scanners (ALS) for digitizing the road environment and detecting road slopes. The study found that ALS data and its corresponding algorithm achieved better detection and delimitation results compared to MLS. Measuring the road from a terrestrial perspective negatively impacted the detection process, while an aerial perspective allowed for scanning of the entire slope structure.
Article
Engineering, Multidisciplinary
Nur Luqman Saleh, Aduwati Sali, Raja Syamsul Azmir Raja Abdullah, Sharifah M. Syed Ahmad, Jiun Terng Liew, Fazirulhisyam Hashim, Fairuz Abdullah, Nur Emileen Abdul Rashid
Summary: This study introduces an enhanced signal processing scheme for detecting mouth-click signals used by blind individuals. By utilizing additional band-pass filtering and other steps, the detection accuracy is improved. Experimental results using artificial signal data showed a 100% success rate in detecting obstacles. The emerging concepts in this research are expected to benefit radar and sonar system applications.
Article
Engineering, Multidisciplinary
Jiqiang Tang, Shengjie Qiu, Lu Zhang, Jinji Sun, Xinxiu Zhou
Summary: This paper studies the magnetic noise level of a compact high-performance magnetically shielded room (MSR) under different operational conditions and establishes a quantitative model for magnetic noise calculation. Verification experiments show the effectiveness of the proposed method.
Review
Engineering, Multidisciplinary
Krzysztof Bartnik, Marcin Koba, Mateusz Smietana
Summary: The demand for miniaturized sensors in the biomedical industry is increasing, and optical fiber sensors (OFSs) are gaining popularity due to their small size, flexibility, and biocompatibility. This study reviews various OFS designs tested in vivo and identifies future perspectives and challenges for OFS technology development from a user perspective.
Article
Engineering, Multidisciplinary
Yue Wang, Lei Zhou, Zihao Li, Jun Wang, Xuangou Wu, Xiangjun Wang, Lei Hu
Summary: This paper presents a 3-D reconstruction method for dynamic stereo vision of metal surface based on line structured light, overcoming the limitation of the measurement range of static stereo vision. The proposed method uses joint calibration and global optimization to accurately reconstruct the 3-D coordinates of the line structured light fringe, improving the reconstruction accuracy.
Article
Engineering, Multidisciplinary
Jaafar Alsalaet
Summary: Order tracking analysis is an effective tool for machinery fault diagnosis and operational modal analysis. This study presents a new formulation for the data equation of the second-generation Vold-Kalman filter, using separated cosine and sine kernels to minimize error and provide smoother envelopes. The proposed method achieves high accuracy even with small weighting factors.
Article
Engineering, Multidisciplinary
Tonglei Cao, Kechen Song, Likun Xu, Hu Feng, Yunhui Yan, Jingbo Guo
Summary: This study constructs a high-resolution dataset for surface defects in ceramic tiles and addresses the scale and quantity differences in defect distribution. An improved approach is proposed by introducing a content-aware feature recombination method and a dynamic attention mechanism. Experimental results demonstrate the superior accuracy and efficiency of the proposed method.
Article
Engineering, Multidisciplinary
Qinghong Fu, Yunxi Lou, Jianghui Deng, Xin Qiu, Xianhua Chen
Summary: Measurement and quantitative characterization of aging-induced gradient properties is crucial for accurate analysis and design of asphalt pavement. This research proposes the composite specimen method to obtain asphalt binders at different depths within the mixture and uses dynamic shear rheometer tests to measure aging-induced gradient properties and reveal internal mechanisms. G* master curves are constructed to investigate gradient aging effects in a wide range. The study finds that the composite specimen method can effectively restore the boundary conditions and that it is feasible to study gradient aging characteristics within the asphalt mixture. The study also observes variations in G* and delta values and the depth range of gradient aging effects for different aging levels.
Article
Engineering, Multidisciplinary
Min Li, Kai Wei, Tianhe Xu, Yali Shi, Dixing Wang
Summary: Due to the limitations of ground monitoring stations in China for the BDS, the accuracy of BDS Medium Earth Orbit (MEO) satellite orbits can be influenced. To overcome this, low Earth orbit (LEO) satellites can be used as additional monitoring stations. In this study, data from two LEO satellites were collected to improve the precise orbit determination of the BDS. By comparing the results with GPS and BDS-2/3 solutions, it was found that including the LEO satellites significantly improved the accuracy of GPS and BDS-2/3 orbits.
