Article
Acoustics
P. Shanmugam, L. Iglesias, J. F. Michaud, D. Alquier, L. Colin, I. Dufour, D. Certon
Summary: This study aimed to develop ultra-wide bandwidth air-coupled capacitive micromachined ultrasonic transducers (CMUTs) for binary gas mixture analysis, based on time-of-flight (ToF) measurements to monitor gas ultrasound velocity variations. The proposed technique showed promising results in detecting CO2/N2 and H2/N2 gas mixtures, with a measured limit of detection (LOD) of 0.3% for CO2 in N2 and 0.15% for H2 in N2, demonstrating high detection sensitivity.
Article
Automation & Control Systems
Lanlin Yu, Xiaodong Cheng, Jacquelien M. A. Scherpen, Junlin Xiong
Summary: This paper proposes an H-2 optimal scheme for reducing the dimension of diffusively coupled second-order systems. It achieves an approximate input-output mapping and preserves crucial structures through a novel graph reconstruction approach.
Article
Computer Science, Interdisciplinary Applications
Guowen Lei, Thiago Lima Silva, Milan Stanko
Summary: A compact formulation has been developed for optimizing early-stage field development planning of multi-reservoir fields, maximizing project economic value. This novel approach includes scalable model for well combination selection, logarithmic piecewise-linear model to approximate well production potential curves, and realistic field development optimization. Simulation analysis shows that logarithmic formulation significantly reduces computational time and improves accuracy over standard SOS2 formulations.
COMPUTERS & CHEMICAL ENGINEERING
(2021)
Article
Mathematics, Applied
Shambhavi Singh, Yves Lucet
Summary: The article discusses how to check if a piecewise-defined function is convex and its applications.
SIAM JOURNAL ON OPTIMIZATION
(2021)
Article
Mathematics
Peixing Yang, Yuan Yang, Jiang Yu
Summary: This paper investigates perturbations of planar general piecewise Hamiltonian systems with nonregular separation lines and the estimation of the maximum number of limit cycles for piecewise linear differential systems. By explicitly expressing the first and second order Melnikov functions, upper bounds of 4 and 5 for the number of limit cycles bifurcated from periodic orbits were obtained.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Mathematics, Applied
Manuel Santos Gutierrez, Valerio Lucarini, Mickael D. Chekroun, Michael Ghil
Summary: This study establishes a strong connection between data-driven and theoretical approaches to achieving efficient and accurate parameterizations for model reduction. Through perturbation expansions, a general stochastic parameterization of weakly coupled dynamical systems is derived, and it is shown that truncation of expansions is not necessary when coupling is additive. Additionally, the study simplifies unwieldy integrodifferential equations into a multilevel Markovian model and establishes an intuitive connection with a generalized Langevin equation. This research supports the physical basis and robustness of the empirical model reduction (EMR) methodology while highlighting the practical relevance of the perturbative expansion used for deriving the parameterizations.
Article
Mathematics, Interdisciplinary Applications
Arshad Ali, Khursheed J. Ansari, Hussam Alrabaiah, Ahmad Aloqaily, Nabil Mlaiki
Summary: In this research paper, a coupled system of piecewise-order differential equations (DEs) with variable kernel and impulsive conditions is studied. DEs with variable kernel have high flexibility due to the freedom of changing the kernel. Existence and stability theory are studied, and sufficient conditions for the main results of the proposed problem are derived. Scheafer's fixed point theorem and Banach fixed point theorem are applied for the result of at least one and unique solution, respectively. Additionally, stability results based on the Ulam-Hyers concept are derived. The obtained results have multi-dimensional applications as it is a coupled system of piecewise fractional-order DEs with variable kernel and impulsive effects.
FRACTAL AND FRACTIONAL
(2023)
Article
Engineering, Mechanical
Akira Saito, Masato Tanaka
Summary: This paper presents a data-driven model order reduction method for piecewise-linear systems based on dynamic mode decomposition (DMD). The method is applied to two representative examples of piecewise linear systems. By extracting dynamic modes and projecting them onto a subspace, the proposed method reduces the degrees of freedom of the system. The reduced order models constructed by this method produce accurate forced response results.
NONLINEAR DYNAMICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Andreas Obermeier, Nikolaus Vollmer, Christoph Windmeier, Erik Esche, Jens-Uwe Repke
Summary: Two approaches for generating piecewise linear surrogate models are proposed in this study, one being a numerical algorithm and the other an optimization-based technique.
COMPUTERS & CHEMICAL ENGINEERING
(2021)
Article
Computer Science, Interdisciplinary Applications
Bo Hou, Chengjian Zhang
Summary: In this paper, the authors propose Crank-Nicolson, high-order compact difference (HOCD), and HOCD-based Richardson extrapolation (RHOCD) methods for solving initial-boundary value problems of semi-linear reaction-diffusion equations with piecewise continuous argument in spatial derivative. It is proven that the computational accuracy of HOCD (and RHOCD) method is O(τ²+h⁴) (and O(τ⁴+h⁴)) under appropriate conditions. The RHOCD method improves the calculation accuracy of the HOCD method in the temporal direction, and the stability of the HOCD method is also analyzed and a global stability criterion is derived. Numerical experiments confirm the computational effectiveness and theoretical accuracy of the proposed methods.
MATHEMATICS AND COMPUTERS IN SIMULATION
(2023)
Article
Mathematics, Applied
Erik T. K. Mau, Michael Rosenblum, Arkady Pikovsky
Summary: Phase reduction is a general approach for describing coupled oscillatory units by focusing on their phases. This paper presents a general framework for obtaining higher-order coupling terms in terms of the coupling parameter for two-dimensional oscillators with arbitrary coupling terms. The theory is applied to accurately predict Arnold's tongue phenomenon for the van der Pol oscillator using higher-order phase reduction.
Article
Computer Science, Information Systems
Gurpreet Kaur, Rekha Agarwal, Vinod Patidar
Summary: This paper proposes a robust color image encryption scheme based on a real fractional Hartley transform with chaotic transform orders. The multilayer scheme combines circular blending of color components using piecewise linear chaotic map (PWLCM), nonlinear processing in spatial domain using piecewise nonlinear chaotic map (PWNCA), and multiple chaotic order fractional Hartley transform to obtain the encrypted image. The experimental results demonstrate the superior performance and robustness of the proposed scheme compared to other similar schemes.
JOURNAL OF KING SAUD UNIVERSITY-COMPUTER AND INFORMATION SCIENCES
(2022)
Article
Engineering, Multidisciplinary
Jack S. Hale, Elisa Schenone, Davide Baroli, Lars A. A. Beex, Stephane P. A. Bordas
Summary: Reduced assembly (RA) is introduced as a new hyper-reduction strategy to drastically reduce the computational costs associated with assembling and projecting large linear systems onto a reduced order basis. RA achieves performance increases up to five times over baseline methods for solving non-linear reaction-diffusion and 3D hyperelasticity problems.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Mathematics, Applied
Qiwei Feng, Bin Han, Peter Minev
Summary: This paper investigates the Poisson interface problem on a smooth curve inside a two-dimensional rectangular region and proposes a compact finite difference scheme for solving it with singular sources, extending the immersed interface method to the highest order of six for uniform Cartesian grids. The coefficient matrix of the proposed scheme is independent of source terms and boundary conditions, allowing for easy implementation and parallel execution.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2021)
Article
Environmental Sciences
Jing Cao
Summary: Reservoir simulation is essential for various computational applications, but can be time-consuming. The KPOD-ITPWL model order reduction method improves computational efficiency by providing higher accuracy and speed similar to existing methods, offering a speedup of about 50 times for the full-order model.
FRESENIUS ENVIRONMENTAL BULLETIN
(2021)
Article
Engineering, Electrical & Electronic
Yongcun Hao, Jiaju Liang, Hao Kang, Weizheng Yuan, Honglong Chang
Summary: This paper presents a high-resolution voltmeter based on applying mode localization in a 3 DOF weakly coupled resonators system. The method detects input voltage by measuring the amplitude ratio shift of the WCRs, with a measured relative shift of amplitude ratio 2918 times higher than that of the resonant frequency. The voltmeter has a noise floor of 3 mu V/root Hz and errors of repeatability and backhaul both less than 3%.
IEEE SENSORS JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Haoqing Zhang, Zhiqiang Yan, Xinlu Wang, Martina Ganova, Honglong Chang, Sona Lassakova, Marie Korabecna, Pavel Neuzil
Summary: This study introduced a single-channel qPCR duplexing method using EvaGreen intercalating dye and FAM probe, offering a cost-effective alternative to probe-based qPCR. The method demonstrated the ability to determine detectable concentration ratios of targets and eliminate fluorescence overspilling, while confirming PCR product specificity through melting curve analysis. The approach was validated on a commercial thermal cycler, increasing its utility for researchers in need of a practical and economical molecular diagnostics tool.
Article
Engineering, Electrical & Electronic
Liang Xue, Bo Yang, Xinguo Wang, Bin Shan, Jiuan Gao, Honglong Chang, Yuanfu Yao
Summary: Data fusion is a new method for reducing sensor drift error and enhancing the accuracy of navigation systems. This paper constructs a redundant MEMS gyroscope system with an optimal configuration structure and designs redundant 4,5,6-gyro systems. An optimal KF algorithm for multisignal fusion is designed to estimate the three-dimensional orthogonal angular rate. The simulation and experimental results demonstrate the effectiveness of the proposed approach in reducing drift error and improving accuracy.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Penglei Zhang, Yahui Li, Chao Ren, Haodong Zhang, Xian Shi, Yu Liu, Mengqiu Li, Yongcun Hao, Honglong Chang, Zhuoqing Yang
Summary: An inertial switch with bi-directional adjustable threshold function is designed, and the adjustable threshold is achieved by electrostatic force. The all-metal structure inertial switch is fabricated based on MEMS technology, with a core structure composed of three-layer parallel plates. The experimental results show a correlation between bias voltage and threshold acceleration, as well as verification of the theoretical analysis.
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2022)
Article
Biochemical Research Methods
Zhiqiang Yan, Haoqing Zhang, Xinlu Wang, Martina Ganova, Tomas Lednicky, Hanliang Zhu, Xiaocheng Liu, Marie Korabecna, Honglong Chang, Pavel Neuzil
Summary: This study developed an image-to-answer algorithm for the analysis of digital polymerase chain reaction (dPCR) chip results. By identifying partitions, rotating images, correcting positions, and addressing fluorescence non-uniformity, this algorithm provides a reliable alternative for statistical analysis of chip-based dPCR systems.
Article
Engineering, Electrical & Electronic
Luhan Zu, Yongcun Hao, Meng Wang, Honglong Chang
Summary: This paper proposes a mechanical sensitivity adjustment method to improve the adjustability of sensitivity of mode-localized sensors using a tunable coupling structure. Experimental results demonstrate that this method has lower non-linearity and larger measurement range, making it a very promising solution for acceleration measurement in high-end industrial applications.
IEEE SENSORS JOURNAL
(2022)
Article
Automation & Control Systems
Hao Wang, Haiyang Quan, Jinqiu Zhou, Long Zhang, Jianbing Xie, Honglong Chang
Summary: This article reports on a MEMS disk resonator gyroscope with superior performance in terms of bias instability, measurement range, and size. The gyroscope achieves high precision measurements and has potential applications in various industries.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Nanoscience & Nanotechnology
Han Li, Zhao Zhang, Luhan Zu, Yongcun Hao, Honglong Chang
Summary: This paper outlines the design of a novel mode-localized electric current sensor based on a mechanically sensitive element of weakly coupled resonator systems. The sensor converts the test current to voltage through a silicon shunt resistor, causing a stiffness perturbation to one resonator. The mode-localization phenomenon alters the energy distribution, and the sensor has a sensitivity of 567/A, a noise floor of 69.3 nA/root Hz, a resolution of 183.6 nA, and a bias instability of 81.6 nA.
MICROSYSTEMS & NANOENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Kai Tao, Boming Lyu, Jian Zhang, Yunjia Li, Honglong Chang, Weizheng Yuan
Summary: This study proposes a novel method of electrostatic charging using flowing tap water, demonstrating the charge stability in liquid-solid contact electrification and advancing a new application in the energy harvesting field.
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2022)
Article
Nanoscience & Nanotechnology
Lu Tian, Qiang Shen, Honglong Chang
Summary: A novel, high-sensitivity progressive wave gyroscope based on acoustooptic effects for measuring rotational angular velocity is proposed and investigated numerically. Using acousto-optic effects to detect changes in refractive index caused by mechanical strain and measuring angular velocity by optical power intensity, the proposed structure achieves high sensitivity and impact resistance, providing an effective solution for enhancing the performance of SAW gyroscopes.
MICROSYSTEMS & NANOENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Jiaying Jian, Pengfan Dong, Zengyun Jian, Ting Zhao, Chen Miao, Honglong Chang, Jian Chen, Yan-Feng Chen, Yan-Bin Chen, Hao Feng, Brice Sorli
Summary: This paper reports a method to fabricate low-power and high switching-ratio RRAM by adjusting the interstice radius between the van der Waals layers of transitional-metal dichalcogenides. The results show that when the ratio of the interstice radius to the radius of the metal ions that form the conductive filaments is near 1, the switching ratio can be increased and the SET power can be reduced simultaneously.
Article
Engineering, Electrical & Electronic
Zhe Zhao, Huipeng Zhou, Yunjia Li, Honglong Chang, Weizheng Yuan, Kai Tao
Summary: Inspired by an electromagnetic generator, a bipolar electret rotatory power generator (e-RPG) with a multi-phase coreshell structure was designed to enhance output performance and achieve precise self-sensing capabilities. A localized rotary corona discharging method was invented to inject both positive and negative charges uniformly, resulting in a significant increase in output power compared to single charge injection. By introducing a core-shell-structured multi-phase electrode design, the e-RPG can accurately detect rotation direction and speed. The proposed e-RPG has potential applications in the Internet of Things, self-powered sensing, and self-sensing of rotational motions.
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2022)
Article
Automation & Control Systems
Qiang Shen, Dengfeng Yang, Jiayu Li, Honglong Chang
Summary: This article proposes a gyroscope array with a two-stages unknown disturbance (UD)-decoupled fusion strategy to maintain high-accuracy bias under unknown disturbances. The array utilizes local estimators and a global state fusion estimator to obtain estimates of the state, bias, and UD of each gyro, achieving optimal state estimation. Experimental results demonstrate significant improvements in accuracy compared to other methods, making this array-based UD-decoupled method a promising approach for practical environment engineering applications.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Honglong Chang
Summary: This paper introduces the basic theories and applications of serial and parallel connections of single-degree-of-freedom micromechanical resonators for sensing. The serial connection uses the amplitude ratio as an output metric and employs mode-localization phenomenon to amplify the signal and suppress common-mode noises, improving the signal-to-noise ratio of sensors. The parallel connection combines resonators with an optimal filter to suppress random noises and further improve the signal-to-noise ratio. Overall, the serial and parallel connections enable calculations of summation, subtraction, and division, leading to improved sensing performance.
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2023)
Article
Chemistry, Multidisciplinary
Jiaying Jian, Honglong Chang, Pengfan Dong, Zewen Bai, Kangnian Zuo
Summary: The study focused on improving the photoelectric performance of a photodetector based on CVD-grown 2D MoS2, finding that annealing and vulcanization treatments significantly enhanced its properties. Methods to determine O-doping concentration and a criterion for transition to a pure state in CVD-grown 2D MoS2 were developed, along with a proposed mechanism explaining the performance variation.