bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel multivariate signal processing-based fault diagnosis approach of rotating machinery under various operating conditions
Authors: Lv Yong , Yang Di , Yuan Rui , Yang Ke , Zhong Hongyu 
Published: March 2022

Abstract
Compared with signals collected by the single sensor, the collected multivariate signals contain more information to reflect the state of mechanical equipment, which has a positive effect on fault diagnosis. However, different acquisition channels and various operating conditions interfere with the extraction of fault features of rotating machinery. To solve this problem, taking rolling bearings as an example in this paper, a novel method is adopted to alleviate these interferences and combined with an improved extreme learning machine (ELM) to achieve intelligent fault diagnosis of rolling bearings under various operating conditions. First, adaptive projection intrinsically transformed multivariate empirical mode decomposition is used to decompose multivariate signals and obtain intrinsic mode functions of each channel to construct feature matrices. Then, nuisance attribute projection (NAP) is employed to alleviate the interference components in the feature matrix, which are originated from different channels and operating conditions. Finally, vectors belonging to the processed feature matrix as samples are input into the proposed weighted extreme learning machine (WELM) for intelligent fault classification. The weighted matrix of the WELM can compress the dimension of the sample and extract sensitive features, and the effectiveness of the proposed fault diagnosis model via the above methods is verified by experiments. Furthermore, comparative experiments show that the proposed fault diagnosis model has higher accuracy than the model combined with NAP and traditional single-hidden layer feedforward neural network or ELM. Therefore, the proposed fault diagnosis model may potentially aid experts on fault diagnosis of rotating machinery under various operating conditions.
Phosphorene grain boundary effect on phonon transport and phononic applications
Authors: Wang Xujun , Wang Quanjie , Liu Xinyu , Huang Zixuan , Liu Xiangjun 
Published: March 2022

Abstract
Grain boundaries (GBs) widely exist in black phosphorene (BP), which plays a vital role in determining the properties of 2D materials. Significant GB effect on the thermal boundary resistance in BP structures is found by using molecular dynamics calculations and lattice dynamic analysis. A remarkably high interface thermal resistance is observed. By analyzing the strain distribution and phonon vibrational spectra, we reveal this high thermal resistance originates from phonon localization and strong phonon boundary scattering induced by the local stress at the GB area. Particularly, it is interesting to find that the partial phonon modes display weak localization when GBs present. The fraction of atoms participating in a particular phonon vibrational mode has been quantified through the calculation of phonon participation ratio. In addition, the thermal boundary resistance is found size-dependent, which further induces interesting thermal rectification effect in the BP structures. A high rectification ratio is obtained by adjusting the structural length and temperature bias. These findings provide a through insight into the GB effects on individual phonon mode transmission across the GBs, and highlight that the GB effect is an important factor and should be taken into account for the applications of BP-based phononic devices.
Offline and online LSTM networks for respiratory motion prediction in MR-guided radiotherapy
Authors: Lombardo Elia , Rabe Moritz , Xiong Yuqing , Nierer Lukas , Cusumano Davide , Placidi Lorenzo , Boldrini Luca , Corradini Stefanie , Niyazi Maximilian , Belka Claus , Riboldi Marco , Kurz Christopher , Landry Guillaume 
Published: March 2022

Abstract

Objective. Gated beam delivery is the current clinical practice for respiratory motion compensation in MR-guided radiotherapy, and further research is ongoing to implement tracking. To manage intra-fractional motion using multileaf collimator tracking the total system latency needs to be accounted for in real-time. In this study, long short-term memory (LSTM) networks were optimized for the prediction of superior–inferior tumor centroid positions extracted from clinically acquired 2D cine MRIs. Approach. We used 88 patients treated at the University Hospital of the LMU Munich for training and validation (70 patients, 13.1 h), and for testing (18 patients, 3.0 h). Three patients treated at Fondazione Policlinico Universitario Agostino Gemelli were used as a second testing set (1.5 h). The performance of the LSTMs in terms of root mean square error (RMSE) was compared to baseline linear regression (LR) models for forecasted time spans of 250 ms, 500 ms and 750 ms. Both the LSTM and the LR were trained with offline (offline LSTM and offline LR) and online schemes (offline+online LSTM and online LR), the latter to allow for continuous adaptation to recent respiratory patterns. Main results. We found the offline+online LSTM to perform best for all investigated forecasts. Specifically, when predicting 500 ms ahead it achieved a mean RMSE of 1.20 mm and 1.00 mm, while the best performing LR model achieved a mean RMSE of 1.42 mm and 1.22 mm for the LMU and Gemelli testing set, respectively. Significance. This indicates that LSTM networks have potential as respiratory motion predictors and that continuous online re-optimization can enhance their performance.
Effects of humidity on the dynamics and electron recombination of a pin-to-pin discharge in He + H2O at atmospheric pressure
Authors: Brisset Alexandra , Harris Benjamin , Dickenson Aaron , Niemi Kari , Walsh James , Wagenaars Erik 
Published: March 2022

Abstract
Control of the plasma chemistry is essential for the effectiveness of atmospheric pressure plasmas in many applications. For this, the effects of the humidity of the feed gas on the discharge chemistry need to be considered. Detailed studies are scarce and many of them are dominated by surface interactions, obscuring any volume effects. Here, a negative nanosecond pulsed discharge is generated in a pin–pin 3 mm gap geometry in He + H2O that enables the study of volume kinetics due to minimal surface area. The effect of humidity on the discharge development, electric field and electron density is investigated through experiments and modelling. It is found that the presence of water vapour affects both the electron density at the start of the pulse (remaining from the previous pulse) and the ionisation rates during the ignition phase, leading to a complex dependence of the discharge development speed depending on the water concentration. The electron decay is studied using the 0D global kinetics model GlobalKin. The dominant reactions responsible for the electron decay depending on the concentration of water vapour are determined by comparing experimental and simulated results and these reactions are grouped in simplified kinetic models. It is found that with water concentrations increasing from 0 to 2500 ppm, the complexity of the dominant reactions increases with in particular O2
+, H2O3
+ and water clusters becoming important for high water concentrations. This work also provides experimental data for validation of kinetic models of plasmas in controlled environments.
Opto-electronic, thermodynamic and charge carriers transport properties of Ta2FeNiSn2 and Nb2FeNiSn2 double half-Heusler alloys
Authors: Berarma Khadidja , Essaoud Saber Sâad , Mousa Ahmad A , Azar Said M , Al-Reyahi Anas Y 
Published: March 2022

Abstract
A computational research study of the structural, electronic, and optical characteristics of double half-Heusler alloys Ta2FeNiSn2 and Nb2FeNiSn2 is presented by performing ab initio calculations. The density functional theory framework employs the full-potential linearized augmented plane wave method to solve Kohn–Sham equation as implemented in the Wien2k code. The exchange-correlation potential is processed by using the local density approximation and the generalized gradient approximation–Perdew, Burke, and Ernzerhof approximations to calculate the total energy and other physical properties. The obtained results showed that both alloys possess high cohesive energies, where Nb2FeNiSn2 (7.213 eV atom−1) is more consistent than Ta2FeNiSn2 (6.249 eV atom−1), these remarkable results support the structural stability for both alloys. Also, the thermodynamic stability of both compounds was confirmed through calculating the formation energy as the obtained results were close to the results obtained in as well as given the Open Quantum Materials Database. Electronic characteristics and chemical bonding are illustrated and discussed by computing the electron charge density, density of states, and band structure. Both alloys show semiconductor behavior with (∼0.5 eV) indirect energy bandgap. Also, we have calculated and analyzed the complex dielectric function, absorption coefficient, as well as, reflectivity spectra for both compounds. The semi local Boltzmann transport theory has been employed to treat temperature effect on thermoelectric properties of Ta2FeNiSn2 and Nb2FeNiSn2 compounds where the obtained results appears that both compounds have high coefficient at the normal condition, and they also have a good power factor at the Fermi level, which emphasizes that the thermoelectric efficiency of the two compounds is good and does not require doping. Also, depending on quasi-harmonic model was used for estimating the heat capacity, the lattice thermal conductivity, the thermal expansion and the Debye temperature under the pressure effects.
Photon-pair blockade in a Josephson-photonics circuit with two nondegenerate microwave resonators
Authors: Ma Sheng-li , Xie Ji-kun , Ren Ya-long , Li Xin-ke , Li Fu-li 
Published: March 2022

Abstract
We propose to generate photon-pair blockade in a Josephson-photonics circuit that consists of a dc voltage-biased Josephson junction in series with a superconducting charge qubit and two nondegenerate microwave resonators. The two-level charge qubit is utilized to create anticorrelations of the charge transport; that is, the simultaneous Cooper pair tunneling events are inhibited. When the Josephson frequency matches the sum of resonance frequencies of the charge qubit and the two resonators, we demonstrate that the two resonators can release their energies in the form of antibunched pairs of two strongly correlated photons. The present work provides a practical way for producing a bright microwave source of antibunched photon pairs, with potential applications ranging from spectroscopy and metrology to quantum information processing.
Compton profile and charge density reconstruction by the maximum entropy method
Authors: Aguiar Julio C , Di Rocco Héctor O 
Published: March 2022

Abstract
The aim of this work is to propose a theoretical procedure to determine the electron momentum density and Compton profile of valence electrons in solids. The procedure consists in a hybrid methodology that combines the maximum entropy method and Dirac-Hartree–Fock formalism, which allows including exchange and correlation effects on valence electrons for distances near the atomic nucleus and that are approximated using the Breit-Wigner distribution function. This technique can be applied for a wide range of crystalline solids. The results and comparisons reported here are for: lithium, beryllium, aluminum, silicon and copper. The application of the model only requires prior knowledge of the Fermi momentum values. In addition, a reconstruction of the valence electron charge density distribution via simple expression of the Compton profile is derived.
Cross-polarization ratio analysis of digital speckle patterns applied to teeth demineralization diagnosis
Authors: Castilho V M , Nunes A M , de Abreu L G , Balthazar W F , da Silva L , O Huguenin J A 
Published: March 2022

Abstract
We propose using the cross-polarization ratio (CPR) of the digital speckle pattern as a parameter to detect enamel erosion. We applied such analysis to successfully detect enamel erosion caused by teeth demineralization. The speckle patterns were produced using an in vitro study in human teeth where the erosion was produced artificially by acid attack. Our result is a proof of principle of the viability to apply CPR in the characterization of enamel erosion, which can be a powerful instrument for early diagnosis of teeth demineralization. This approach proved to be very sensitive to variation in speckle patterns compared with other traditional speckle patterns analyses.
Comparisons between high power fiber systems in the presence of radiation induced photodarkening
Authors: Tao Mengmeng , Chen Hongwei , Feng Guobin , Wang Lijun , Ye Jingfeng , Wang Yamin , Ye Xisheng , Chen Weibiao 
Published: March 2022

Abstract
Performance of high power fiber lasers and amplifiers with different pump sources are evaluated in the presence of radiation induced photodarkening in post-irradiated active fibers. Evolutions of output power and thermal mode instability threshold under different radiation doses are examined and analyzed. Severe degradation in both output power and thermal mode instability threshold is recorded for high power fiber systems with their active fibers exposed to radiations. Comparisons show that, amplifiers present a relatively better performance than lasers in adverse environments. Besides, 976 nm pump source is more favorable for high power laser sources in radioactive applications, even though 915 nm pump ensures a much lower temperature profile inside the active fiber.
A neurostimulator system for real, sham, and multi-target transcranial magnetic stimulation
Authors: Memarian Sorkhabi Majid , Denison Timothy 
Published: March 2022

Abstract

Objective. Transcranial magnetic stimulation (TMS) is a clinically effective therapeutic instrument used to modulate neural activity. Despite three decades of research, two challenging issues remain, the possibility of changing the (a) stimulated spot and (b) stimulation type (real or sham) without physically moving the coil. In this study, a second-generation programmable TMS device with advanced stimulus shaping is introduced that uses a five-level cascaded H-bridge inverter and phase-shifted pulse-width modulation. The principal idea of this research is to obtain real, sham, and multi-locus stimulation using the same TMS system. Approach. We propose a two-channel modulation-based magnetic pulse generator and a novel coil arrangement, consisting of two circular coils with a physical distance of 20 mm between the coils and a control method for modifying the effective stimulus intensity, which leads to the live steerability of the target and type of stimulation. Main results. Based on the measured system performance, the stimulation profile can be steered ±20 mm along a line from the centroid of the coil locations by modifying the modulation index. Significance. The proposed system supports electronic control of the stimulation spot without physical coil movement, resulting in tunable modulation of targets, which is a crucial step towards automated TMS machines.
Evaluating the clinical benefit of brain-computer interfaces for control of a personal computer
Authors: Fry Adam , Chan Ho Wing , Harel Noam Y , Spielman Lisa A , Escalon Miguel X , Putrino David F 
Published: March 2022

Abstract
Brain-computer interfaces (BCIs) enabling the control of a personal computer could provide myriad benefits to individuals with disabilities including paralysis. However, to realize this potential, these BCIs must gain regulatory approval and be made clinically available beyond research participation. Therefore, a transition from engineering-oriented to clinically oriented outcome measures will be required in the evaluation of BCIs. This review examined how to assess the clinical benefit of BCIs for the control of a personal computer. We report that: (a) a variety of different patient-reported outcome measures can be used to evaluate improvements in how a patient feels, and we offer some considerations that should guide instrument selection. (b) Activities of daily living can be assessed to demonstrate improvements in how a patient functions, however, new instruments that are sensitive to increases in functional independence via the ability to perform digital tasks may be needed. (c) Benefits to how a patient survives has not previously been evaluated but establishing patient-initiated communication channels using BCIs might facilitate quantifiable improvements in health outcomes.
Based on RBF Neural Network of Hypersonic Re-entry Vehicle Attitude Control
Authors: Chang Shunzhang , Liu Shiyue , Chen Jiabin 
Published: March 2022

Abstract
In this paper, an attitude control method combining radial basis (RBF) neural network with integral sliding mode control is proposed for the re-entry stage of hypersonic vehicle with uncertain aerodynamic parameters and atmospheric density. Firstly, the Time-scale separation model of nonlinear equations for aircraft is established. Meanwhile, the feedback linearization method is used to linearize the time scale separation model. For fast and slow control subloops, a global sliding mode variable structure control was designed, and the stability of the closed-loop system was verified by Lyapunov theory. Finally, RBF neural network online regulation law is designed to adjust the controller parameters online to reduce chattering. The simulation results show that the controller can maintain good dynamic characteristics even when the aerodynamic data are greatly deviated.
Robust Decentralized Fuzzy Controller Design for Nonlinear Large-Scale Interconnected Descriptor Systems
Authors: Chang Wen-Jer , Su Che-Lun , Pen Chin-Lin , Lin Zi-Yao 
Published: March 2022

Abstract
This paper dealt with the robust control problem for fuzzy large-scale descriptor systems (FLSDS) with uncertainties. First, each nonlinear subsystem of the large-scale descriptor system was described as a FLSDS with interconnectivity and uncertainty. Based on the proportional-plus-derivative state feedback (PD) method, the decentralized fuzzy controller in each subsystem was designed to stabilize the whole system. In order to solve the uncertainties problem in the control system simply, a benefits robust approach has been proposed. The final stability conditions can be recast into the linear matrix inequality (LMI) problem by the Schur complement. At last, a numerical example was given to illustrate the control design procedure and its effectiveness.
Study on the Morphology Characteristics of Epoxy Resin of Composite Insulator under Acid-heat Condition
Authors: Pan Wenwu , Zhang Dandan , Lu Ming , Li Zhenbiao , Gao Chao , Wan Zhiyu 
Published: March 2022

Abstract
Whether epoxy resin is degraded or not in composite insulators is the most direct criterion to distinguish Decay-like fracture from brittle fracture and normally mechanical fracture. During the actual operation of composite insulators, the nitric acid produced by partial discharge and abnormal heating will accelerate the degradation and deterioration of epoxy resin of composite insulators. In this paper, the experimental platform under acid-heat condition is built by using heating furnace, grinding bottle and serpentine condensation tube, and the acid-heat deterioration experiments are carried out under 60 °C (3 mol/L and 5 mol/L) and 80 °C (3 mol/L and 5 mol/L) condition. The macroscopic and microscopic morphologies of epoxy resin after acid-heat deterioration are analyzed, and the morphology changes of epoxy resin under the influence of acid-heat coupling field are studied. Firstly, it is concluded that the epoxy resin changes directly from colorless to light yellow, and then from light yellow to dark yellow under the influence of acid-heat deterioration. In addition, in the early stage of deterioration, the bulge on the surface of epoxy resin decreases gradually. Meanwhile, the maximum height difference and standard deviation of the surface profile of epoxy resin also gradually decreases, and the roughness decreases. In the later stage of deterioration, cracks appear on the surface of epoxy resin and some epoxy resins fall off. At the same time, the maximum height difference and standard deviation of surface profile of epoxy resin increases.
Research on Micro-motion Modeling and Feature Extraction of Passive Bistatic Radar Based on CMMB Signal
Authors: Xia Saiqiang , Jiang Haiman , Cai Wanyong , Yang Jun , Zhang Chaowei , Chen Wenfeng 
Published: March 2022

Abstract
Passive bistatic radar has unique advantages in studying Micro-Doppler effect because of its system characteristics. China Mobile Multimedia Broadcasting (CMMB) as a broad range of radio and television signal, its signal adopts multi-carrier Orthogonal Frequency Division Multiplexing (OFDM) technology, can be used as a good illuminator. Based on the CMMB signal, the scattering point model of helicopter’s echo is established, and the influencing factors of Micro-Doppler frequency are analyzed. On this basis, the Singular-spectrum Analysis combined with Time-frequency analysis and autocorrelation method is used to extract the target micro-motion characteristics. The simulation results verify the rationality of the micro-motion model and the effectiveness of the feature extraction method in this paper.
Development of an Integrated Simulation Platform for Modelling and Simulation of the Energy Consumption of a Multi-zone Building
Authors: Zhang Jie , Liu-Henke Xiaobo , Vietor Thomas 
Published: March 2022

Abstract
This paper focuses on a simulation platform to model and simulate the energy consumption of a building with multiple zones under the influence of daily and seasonal environmental factors, as well as the impact of the HVAC system and human activities. By using model-based requirements engineering (MBRE), the requirements of the simulation platform are hierarchically derived and specified. On this basis, the simulation platform is designed and developed. With the help of the simulation platform, it is possible to obtain a mathematical model for a realistic description of the thermodynamics and energy consumption of the individual zones of a building, which can be used as a basis for the model-based development of the energy management system, e.g. intelligent energy dispatch strategy. In the following, the concept of the simulation platform and the process will be demonstrated and validated with an application example of the research building Open Mobility Lab (OML).
Study on the Adaptive Test Modelling Based on Knowledge Graph in the Domain of Substation
Authors: Weizhou WANG , Xilan ZHAO , Qi GAO , Lu LIU , Changnian LIN 
Published: March 2022

Abstract
Traditional tests in the substation training fail to fit the ability of the operation and maintenance personnel and precisely describe their weakness. In this paper, an adaptive test model based on the knowledge graph in the domain of substation is constructed. With the help of the knowledge point correlations in the knowledge graph, the model updates the knowledge level of the testee in real time according to the response of each question, and automatically selects the next question that fits the individual. In cases where the test question covers different knowledge amount, the model constructs the knowledge state space or the adjacency/reachability matrix to infer the knowledge mastery, which improves the test efficiency and quality by reasonably reducing the number of questions during the test. Calculation results demonstrate that the model can accurately capture the weakness the substation personnel and has broad application prospects on evaluations in the vocational education.