bluuebunny/crossref_metadata_2025_split huggingface dataset:
A multistart tabu search-based method for feature selection in medical applications
Authors: Pacheco Joaquín , Saiz Olalla , Casado Silvia , Ubillos Silvia 
Published: October 2023

AbstractIn the design of classification models, irrelevant or noisy features are often generated. In some cases, there may even be negative interactions among features. These weaknesses can degrade the performance of the models. Feature selection is a task that searches for a small subset of relevant features from the original set that generate the most efficient models possible. In addition to improving the efficiency of the models, feature selection confers other advantages, such as greater ease in the generation of the necessary data as well as clearer and more interpretable models. In the case of medical applications, feature selection may help to distinguish which characteristics, habits, and factors have the greatest impact on the onset of diseases. However, feature selection is a complex task due to the large number of possible solutions. In the last few years, methods based on different metaheuristic strategies, mainly evolutionary algorithms, have been proposed. The motivation of this work is to develop a method that outperforms previous methods, with the benefits that this implies especially in the medical field. More precisely, the present study proposes a simple method based on tabu search and multistart techniques. The proposed method was analyzed and compared to other methods by testing their performance on several medical databases. Specifically, eight databases belong to the well-known repository of the University of California in Irvine and one of our own design were used. In these computational tests, the proposed method outperformed other recent methods as gauged by various metrics and classifiers. The analyses were accompanied by statistical tests, the results of which showed that the superiority of our method is significant and therefore strengthened these conclusions. In short, the contribution of this work is the development of a method that, on the one hand, is based on different strategies than those used in recent methods, and on the other hand, improves the performance of these methods.
Plant‐wide processes monitoring and fault tracing based on causal graphical model
Authors: Chen Xiaolu , Yang Ying , Wang Jing 
Published: October 2023

AbstractPlant‐wide processes are usually characterized by large scale, multiple operating units and complicated interactions. Effective monitoring for such processes is imperative and challenging. Traditional data‐driven methods have some limitations due to the neglect of internal relationships between operating units. This paper proposes a plant‐wide monitoring and diagnostic framework based on the multi‐variate statistical analysis and causal graphical inference. Initially, the optimized process decomposition is performed by combining the mechanistic knowledge and historical data from the perspective of improving the monitoring performance. Taking into account the fact that shared variables among the different subsystems lead to the information interaction rather than being independent as in the existing methods, the multi‐variate causal model based on probability density estimation is established to identify the quantitative association of the process variables in a single subsystem. The complete model is structured by the link of shared variables. Finally, system anomalies are detected by changes in the probability density of the observed variables; the root cause is pinpointed by the causal inference. Experiments with the Tenessee Eastman (TE) process and Panamax bulk carriers demonstrate the applicability of the proposed methodology.
Data‐driven power system dynamic security assessment under adversarial attacks: Risk warning based interpretation analysis and mitigation
Authors: Chen Zhebin , Ren Chao , Xu Yan , Dong Zhao Yang , Li Qiaoqiao 
Published: October 2023

AbstractPower system dynamic security assessment (DSA) has long been essential for protecting the system from the risk of cascading failures and wide‐spread blackouts. The machine learning (ML) based data‐driven strategy is promising due to its real‐time computation speed and knowledge discovery capacity. However, ML algorithms are found to be vulnerable against well‐designed malicious input samples that can lead to wrong outputs. Adversarial attacks are implemented to measure the vulnerability of the trained ML models. Specifically, the targets of attacks are identified by interpretation analysis that the data features with large SHAP values will be assigned with perturbations. The proposed method has the superiority that an instance‐based DSA method is established with interpretation of the ML models, where effective adversarial attacks and its mitigation countermeasure are developed by assigning the perturbations on features with high importance. Later, these generated adversarial examples are employed for adversarial training and mitigation. The simulation results present that the model accuracy and robustness vary with the quantity of adversarial examples used, and there is not necessarily a trade‐off between these two indicators. Furthermore, the rate of successful attacks increases when a greater bound of perturbations is permitted. By this method, the correlation between model accuracy and robustness can be clearly stated, which will provide considerable assistance in decision making.
Risk‐averse perimeter control for alleviating the congestion of an urban traffic network system with uncertainties
Authors: Shi Yuntao , Zhang Ying , Yin Xiang , Liu Weichuan , Cheng Tingshen 
Published: October 2023

AbstractThe perimeter control method is an effective way to alleviate traffic congestion that is based on Macroscopic Fundamental Diagrams (MFDs). However, the strategy may lead to congestion when it ignores the uncertainty of MFDs. To address this problem, this paper presents a risk‐averse perimeter control method. First, the urban traffic network system with uncertainty is modeled using a neural network and scenario tree. Then, this research quantifies the congestion risk caused by uncertainty using an average value‐at‐risk. The next step sees the design of a risk‐averse model predictive control (MPC) controller that takes the multi‐stage risk as the optimization objective and improves robustness by interpolating between the conventional stochastic and worst‐case MPC formulations. Finally, this paper analyzes the risk‐sensitive stability of an urban traffic network system and gives a solvable form of risk‐averse optimal control for this system. Finally, two simulations are conducted to verify the presented method's validity and superiority for an urban traffic network system with uncertainties. The simulation results show that the risk‐averse perimeter control method presented by this paper is superior because it reduces the total travel time by 12.98% compared to Stochastic MPC, by 15.96% compared to bang‐bang control, and by 14.54% compared to proportional‐integral.
Dark halos around solar active regions
Authors: Lezzi S. M. , Andretta V. , Murabito M. , Del Zanna G. 
Published: October 2023

Context. Dark areas around active regions (ARs) were first observed in chromospheric lines more than a century ago and are now associated with the Hα fibril vortex around ARs. Nowadays, large areas surrounding ARs with reduced emission relative to the quiet Sun (QS) are also observed in spectral lines emitted in the transition region (TR) and the low corona. For example, they are clearly seen in the SDO/AIA 171 Å images. We name these chromospheric and TR-coronal dark regions “dark halos” (DHs). Coronal DHs are poorly studied and, because their origin is still unknown, to date it is not clear if they are related to the chromospheric fibrillar ones. Furthermore, they are often mistaken for coronal holes (CHs).
Aims. Our goal is to characterize the emission properties of a DH by combining, for the first time, chromospheric, TR, and coronal observations in order to provide observational constraints for future studies on the origin of DHs. This study also aims to investigate the different properties of DHs and CHs and provide a quick-look recipe to distinguish between them.
Methods. We studied the DH around AR NOAA 12706 and the southern CH that were on the disk on April 22, 2018 by analyzing IRIS full-disk mosaics and SDO/AIA filtergrams to evaluate their average intensities, normalized to the QS. In addition, we used the AIA images to derive the DH and CH emission measure (EM) and the IRIS Si IV 1393.7 Å line to estimate the nonthermal velocities of plasma in the TR. We also employed SDO/HMI magnetograms to study the average magnetic field strength inside the DH and the CH.
Results. Fibrils are observed all around the AR core in the chromospheric Mg II h&k IRIS mosaics, most clearly in the h3 and k3 features. The TR emission in the DH is much lower than in the QS area, unlike in the CH. Moreover, the DH is much more extended in the low corona than in the chromospheric Mg II h3 and k3 images. Finally, the intensities, EM, spectral profile, nonthermal velocity, and average magnetic field strength measurements clearly show that DHs and CHs exhibit different characteristics, and therefore should be considered as distinct types of structures on the Sun.
A real-time deep learning-based system for colorectal polyp size estimation by white-light endoscopy: development and multicenter prospective validation
Authors: Wang Jing , Li Ying , Li Shuyu , Yu Honggang , Chen Boru , Cheng Du , Liao Fei , Tan Tao , Xu Qinghong , Liu Zhifeng , Huang Yuan , Zhu Ci , Cao Wenbing , Yao Liwen , Wu Zhifeng , Wu Lianlian , Zhang Chenxia , Xiao Bing , Xu Ming , Liu Jun 
Published: October 2023

Abstract
Background The choice of polypectomy device and surveillance intervals for colorectal polyps are primarily decided by polyp size. We developed a deep learning-based system (ENDOANGEL-CPS) to estimate colorectal polyp size in real time.
Methods ENDOANGEL-CPS calculates polyp size by estimating the distance from the endoscope lens to the polyp using the parameters of the lens. The depth estimator network was developed on 7297 images from five virtually produced colon videos and tested on 730 images from seven virtual colon videos. The performance of the system was first evaluated in nine videos of a simulated colon with polyps attached, then tested in 157 real-world prospective videos from three hospitals, with the outcomes compared with that of nine endoscopists over 69 videos. Inappropriate surveillance recommendations caused by incorrect estimation of polyp size were also analyzed.
Results The relative error of depth estimation was 11.3% (SD
6.0%) in successive virtual colon images. The concordance correlation coefficients (CCCs)
between system estimation and ground truth were 0.89 and 0.93 in images of a simulated colon
and multicenter videos of 157 polyps. The mean CCC of ENDOANGEL-CPS surpassed all endoscopists
(0.89 vs. 0.41 [SD 0.29]; P<0.001). The relative accuracy of
ENDOANGEL-CPS was significantly higher than that of endoscopists (89.9% vs. 54.7%; P<0.001). Regarding inappropriate surveillance recommendations, the
system's error rate is also lower than that of endoscopists (1.5% vs. 16.6%; P<0.001).
Conclusions ENDOANGEL-CPS could potentially improve the accuracy of colorectal polyp size measurements and size-based surveillance intervals.
A laser-based system to heat nuclear fuel pellets at high temperature
Authors: Quintal C. Cifuentes , Reymond M. , Fiorito F. , Martin F. , Pontillon M. , Richaud J. C. , Doualle T. , Pontillon Y. , Gallais L. 
Published: October 2023

Annealing tests are of utmost importance in nuclear fuel research, particularly to study the thermophysical properties of the material, microstructure evolution, or the released gas as a function of temperature. As an alternative to conventional furnace or induction annealing, we report on a laser-heating experiment allowing one to heat a nuclear fuel pellet made of uranium dioxide, UO2, or potentially other nuclear fuel pellets in an isothermal and controlled manner. For that purpose, we propose to use an indirect heating method based on a two compartment tungsten crucible, one containing the sample and the other acting as a laser susceptor for efficient and homogeneous heating of the assembly. With this concept, we demonstrate the heating of UO2 samples up to 1500 °C at a maximum heating rate of 30 °C/s with the use of two 500 W lasers. The system is, however, scalable to higher heating rates or higher temperatures by increasing the laser power up to few kW. The experiment has been designed to heat a pressurized water reactor fuel pellet, but the concept could be easily applied to other sample geometries or materials.
Influence of avalanche transistor switching mode on waveform characteristics of solid-state pulse source
Authors: Cheng Zhenbo , Ning Hui , Tang Chuanxiang , Yan Youjie , Zhao Wei , Zhu Meiqi , Cai Hao 
Published: October 2023

The design of the Marx circuit based on avalanche transistors (ATs) is one of the effective techniques for developing solid-state pulse sources to generate nanosecond pulses. However, the influence of the avalanche transistor as a switching device on the output pulse characteristics is still unclear. In this study, investigating the switching mechanism of the AT with a mixed-mode simulation of the semiconductor device has been accomplished. An experiment has checked the simulation model’s transient switching characteristics. The switching mechanisms of ATs in the Marx circuit were divided into base triggering mode (BTM) and voltage ramp mode (VRM). This paper proposes a modified circuit for adjusting the output pulse parameters of solid-state pulse sources. The results show that to satisfy the simulation accuracy, the width parameter of the AT model in the BTM must be 100 μm, much less than the actual physical size. Because of the higher electric field when the initial impact ionization occurs, the AT operates at a higher switching speed in the VRM than in the BTM. In addition, since the carriers of initial impact ionization locate at the p–n0 interface or the n0–n+ interface, the AT switching process will oscillate in the VRM. All ATs in the modified Marx circuit switch to operate in the BTM. The leading edge of the output pulse increases from 275 to 1125 ps, and the pulse trailing oscillation has disappeared. The research results provide an important technical means for optimizing the output waveform of solid-state pulse sources.
Characterizing the multi-dimensional reaction dynamics of dihalomethanes using XUV-induced Coulomb explosion imaging
Authors: Walmsley T. , Unwin J. , Allum F. , Bari S. , Boll R. , Borne K. , Brouard M. , Bucksbaum P. , Ekanayake N. , Erk B. , Forbes R. , Howard A. J. , Eng-Johnsson P. , Lee J. W. L. , Liu Z. , Manschwetus B. , Mason R. , Passow C. , Peschel J. , Rivas D. , Rolles D. , Rörig A. , Rouzée A. , Vallance C. , Ziaee F. , Burt M. 
Published: October 2023

Site-selective probing of iodine 4d orbitals at 13.1 nm was used to characterize the photolysis of CH2I2 and CH2BrI initiated at 202.5 nm. Time-dependent fragment ion momenta were recorded using Coulomb explosion imaging mass spectrometry and used to determine the structural dynamics of the dissociating molecules. Correlations between these fragment momenta, as well as the onset times of electron transfer reactions between them, indicate that each molecule can undergo neutral three-body photolysis. For CH2I2, the structural evolution of the neutral molecule was simultaneously characterized along the C–I and I–C–I coordinates, demonstrating the sensitivity of these measurements to nuclear motion along multiple degrees of freedom.
SEResUTer: a deep learning approach for accurate ECG signal delineation and atrial fibrillation detection
Authors: Li Xinyue , Cai Wenjie , Xu Bolin , Jiang Yupeng , Qi Mengdi , Wang Mingjie 
Published: October 2023

Abstract

Objective. Accurate detection of electrocardiogram (ECG) waveforms is crucial for computer-aided diagnosis of cardiac abnormalities. This study introduces SEResUTer, an enhanced deep learning model designed for ECG delineation and atrial fibrillation (AF) detection. Approach. Built upon a U-Net architecture, SEResUTer incorporates ResNet modules and Transformer encoders to replace convolution blocks, resulting in improved optimization and encoding capabilities. A novel masking strategy is proposed to handle incomplete expert annotations. The model is trained on the QT database (QTDB) and evaluated on the Lobachevsky University Electrocardiography Database (LUDB) to assess its generalization performance. Additionally, the model’s scope is extended to AF detection using the the China Physiological Signal Challenge 2021 (CPSC2021) and the China Physiological Signal Challenge 2018 (CPSC2018) datasets. Main results. The proposed model surpasses existing traditional and deep learning approaches in ECG waveform delineation on the QTDB. It achieves remarkable average F1 scores of 99.14%, 98.48%, and 98.46% for P wave, QRS wave, and T wave delineation, respectively. Moreover, the model demonstrates exceptional generalization ability on the LUDB, achieving average SE, positive prediction rate, and F1 scores of 99.05%, 94.59%, and 94.62%, respectively. By analyzing RR interval differences and the existence of P waves, our method achieves AF identification with 99.20% accuracy on the CPSC2021 test set and demonstrates strong generalization on CPSC2018 dataset. Significance. The proposed approach enables highly accurate ECG waveform delineation and AF detection, facilitating automated analysis of large-scale ECG recordings and improving the diagnosis of cardiac abnormalities.
Scalar-induced gravitational wave interpretation of PTA data: the role of scalar fluctuation propagation speed
Authors: Balaji Shyam , Domènech Guillem , Franciolini Gabriele 
Published: October 2023

AbstractPulsar timing arrays gathered evidence of the presence of a gravitational wave background around nHz frequencies. If the gravitational wave background was induced by large and Gaussian primordial fluctuations, they would then produce too many sub-solar mass primordial black holes. We show that if at the time of gravitational wave generation the universe was dominated by a canonical scalar field, with the same equation of state as standard radiation but a higher propagation speed of fluctuations, one can explain the gravitational wave background with a primordial black hole counterpart consistent with observations. Lastly, we discuss possible ways to test this model with future gravitational wave detectors.
Determination of mathematical expectations of two weighting statistics for ensemble time scales
Authors: Wu Yiwei , Liu Siran 
Published: October 2023

Abstract
The Bureau International des Poids et Mesures uses the ALGOS algorithm to generate the Echelle Atomique Libre. The original and new ALGOS weighting algorithms employ two different statistics to calculate the weights, resulting in different experimental phenomena. These two statistics are believed to be the keys to analyzing these experimental phenomena, because the statistical characteristics (e.g. the mathematical expectations and variances) of the statistics completely determine the statistical characteristics of the weights, and subsequently the experimental phenomena. The core work conducted in this study is to derive the analytical expressions of the mathematical expectations of these two statistics under ideal conditions and to validate them empirically. This paper provides a theoretical analysis of these expressions and discusses the relationships between them and the mathematical expectations of the Allan variances. These expressions theoretically reveal the reasons behind the experimental phenomena, especially why hydrogen masers are assigned lower weights in the original ALGOS weighting algorithm but higher weights in the new one. According to the derivation process, these analytical expressions are universally applicable and can also be applied to time-keeping laboratories. In the future, this work can be extended to determine the theoretical statistic and weight performances of different types of frequency standards quantitatively for time-keeping laboratories under both ideal and non-ideal conditions, providing a theoretical basis for improving the design of ensemble time scale algorithms. In the appendix, a method of obtaining the experimental variances and probability density functions (PDFs) of these two statistics is additionally proposed. The two-sample Kolmogorov–Smirnov test is presented to compare the experimental and theoretical PDFs of an example.
The JET hybrid scenario in Deuterium, Tritium and Deuterium-Tritium
Authors: Hobirk J. , Challis C.D. , Kappatou A. , Lerche E. , Keeling D. , King D. , Aleiferis S. , Alessi E. , Angioni C. , Auriemma F. , Baruzzo M. , Belonohy É. , Bernardo J. , Boboc A. , Carvalho I.S. , Carvalho P. , Casson F.J. , Chomiczewska A. , Citrin J. , Coffey I.H. , Conway N.J. , Douai D. , Delabie E. , Eriksson B. , Eriksson J. , Ficker O. , Field A.R. , Fontana M. , Fontdecaba J.M. , Frassinetti L. , Frigione D. , Gallart D. , Garcia J. , Gelfusa M. , Ghani Z. , Giacomelli L. , Giovannozzi E. , Giroud C. , Goniche M. , Gromelski W. , Hacquin S. , Ham C. , Hawkes N.C. , Henriques R.B. , Hillesheim J.C. , Ho A. , Horvath L. , Ivanova-Stanik I. , Jacquet P. , Jaulmes F. , Joffrin E. , Kim H.T. , Kiptily V. , Kirov K. , Kos D. , Kowalska-Strzeciwilk E. , Kumpulainen H. , Lawson K. , Lennholm M. , Litaudon X. , Litherland-Smith E. , Lomas P.J. , de la Luna E. , Maggi C.F. , Mailloux J. , Mantsinen M.J. , Maslov M. , Matthews G. , McClements K.G. , Meigs A.G. , Menmuir S. , Milocco A. , Miron I.G. , Moradi S. , Morales R.B. , Nowak S. , Orsitto F. , Patel A. , Piron L. , Prince C. , Pucella G. , Peluso E. , Perez von Thun C. , Rachlew E. , Reux C. , Rimini F. , Saarelma S. , Schneider P. A , Scully S. , Sertoli M. , Sharapov S. , Shaw A. , Silburn S. , Sips A. , Siren P. , Sozzi C. , Solano E.R. , Stancar Z. , Stankunas G. , Stuart C. , Sun H.J. , Szepesi G. , Valcarcel D. , Valisa M. , Verdoolaege G. , Viola B. , Wendler N. , Zerbini M. ,   JET Contributors
Published: October 2023

Abstract
The JET hybrid scenario has been developed from low plasma current carbon wall discharges to the record-breaking Deuterium-Tritium plasmas obtained in 2021 with the ITER-like Be/W wall. The development started in pure Deuterium with refinement of the plasma current, and toroidal magnetic field choices and succeeded in solving the heat load challenges arising from 37 MW of injected power in the ITER like wall environment, keeping the radiation in the edge and core controlled, avoiding MHD instabilities and reaching high neutron rates. The Deuterium hybrid plasmas have been re-run in Tritium and methods have been found to keep the radiation controlled but not at high fusion performance probably due to time constraints. For the first time this scenario has been run in Deuterium-Tritium (50:50). These plasmas were re-optimised to have a radiation-stable H-mode entry phase, good impurity control through edge Ti
gradient screening and optimised performance with fusion power exceeding 10 MW for longer than three alpha particle slow down times, 8.3 MW averaged over 5 s and fusion energy of 45.8 MJ.