PHILEMON UTEN EMMOH, christopher ifeanyi Eke, Timothy Moses
Selection of important features is very vital in machine learning tasks involving high-dimensional dataset with large features. It helps in reducing the dimensionality of a dataset and improving model performance. Most of the feature selection techniques have restriction in the kind of dataset to be used. This study proposed a feature selection technique that is based on statistical lift measure to select important features from a dataset. The proposed technique is a generic approach that can be used in any binary classification dataset. The technique successfully determined the most important feature subset and outperformed the existing techniques. The proposed technique was tested on lungs cancer dataset and happiness classification dataset. The effectiveness of the proposed technique in selecting important features subset was evaluated and compared with other existing techniques, namely Chi-Square, Pearson Correlation and Information Gain. Both the proposed and the existing techniques were evaluated on five machine learning models using four standard evaluation metrics such as accuracy, precision, recall and F1-score. The experimental results of the proposed technique on lung cancer dataset shows that logistic regression, decision tree, adaboost, gradient boost and random forest produced a predictive accuracy of 0.919%, 0.935%, 0.919%, 0.935% and 0.935% respectively, and that of happiness classification dataset produced a predictive accuracy of 0.758%, 0.689%, 0.724%, 0.655% and 0.689% on random forest, k-nearest neighbor, decision tree, gradient boost and cat boost respectively, which outperformed the existing techniques.
Hall anomaly related to deviations in Hall carrier concentrations have always been recognized as signs of charge incoherence in organic semiconductors, which lack ordered lattices. In this paper, we show that the Hall carrier concentration anomaly in doped polymers might be a result of semimetallization. Based on the observation of semimetal-like states, a dual-channel model, in which electrons and holes compensate the Hall voltages of each other, is employed to account for the anomaly. Observations of possible nonlinear Hall effect and temperature dependent Hall signs further support the origin of Hall anomaly from semimetal states.
Video synthetic aperture radar (video SAR) has been successfully applied in many fields and the registration of the video SAR images has been proven to be a crucial step in their preprocessing. However, video SAR images exhibit more severe image differences because of the unique imaging mechanism and the immature imaging methods. This results in existing registration methods failing to achieve satisfactory registration outcomes for video SAR images. The convolutional neural network (CNN) can contribute to improving registration performance. Nevertheless, CNN-based registration methods must be driven by a large amount of labeled data, which is impractical for video SAR images. Therefore, to tackle these problems, we propose an unsupervised end-to-end deep registration method for video SAR images. First, an end-to-end deep registration model (DRM) is proposed to improve the registration performance for video SAR images. In the proposed DRM, the offset field is utilized to indirectly calculate the registered parameters and we construct a CNN, MUnet, to regress the offset field accurately. We also develop a differentiable H-transform and a differentiable spatial transformation to implement the mapping from end to end while allowing DRM to backpropagate the losses during the training phase. Meanwhile, we borrow intensity-based methods to further optimize the registration results. Furthermore, we propose an unsupervised deep training strategy that can use the generated pseudodata with pseudolabel to train the proposed DRM in the absence of large amounts of labeled data. Experiment results on multiple data demonstrate the effectiveness of the proposed registration method.
Pavel Pereslavtsev, Christian Bachmann, Joelle Elbez-Uzan
et al.
There is widespread use of nuclear radiation for medical imagery and treatments. Worldwide, almost 40 million treatments are performed per year. There are also applications of radiation sources in other commercial fields, e.g., for weld inspection or steelmaking processes, in consumer products, in the food industry, and in agriculture. The large number of neutrons generated in a fusion reactor such as DEMO could potentially contribute to the production of the required radioactive isotopes. The associated commercial value of these isotopes could mitigate the capital investments and operating costs of a large fusion plant. The potential of producing various radioactive isotopes was studied from material pieces arranged inside a DEMO equatorial port plug. In this location, they are exposed to an intensive neutron spectrum suitable for a high isotope production rate. For this purpose, the full 3D geometry of one DEMO toroidal sector with an irradiation chamber in the equatorial port plug was modeled with an MCNP code to perform neutron transport simulations. Subsequent activation calculations provide detailed information on the quality and composition of the produced radioactive isotopes. The technical feasibility and the commercial potential of the production of various isotopes in the DEMO port are reported.
In this paper, the Merkle-Transformer model is introduced as an innovative approach designed for financial data processing, which combines the data integrity verification mechanism of Merkle trees with the data processing capabilities of the Transformer model. A series of experiments on key tasks, such as financial behavior detection and stock price prediction, were conducted to validate the effectiveness of the model. The results demonstrate that the Merkle-Transformer significantly outperforms existing deep learning models (such as RoBERTa and BERT) across performance metrics, including precision, recall, accuracy, and F1 score. In particular, in the task of stock price prediction, the performance is notable, with nearly all evaluation metrics scoring above 0.9. Moreover, the performance of the model across various hardware platforms, as well as the security performance of the proposed method, were investigated. The Merkle-Transformer exhibits exceptional performance and robust data security even in resource-constrained environments across diverse hardware configurations. This research offers a new perspective, underscoring the importance of considering data security in financial data processing and confirming the superiority of integrating data verification mechanisms in deep learning models for handling financial data. The core contribution of this work is the first proposition and empirical demonstration of a financial data analysis model that fuses data integrity verification with efficient data processing, providing a novel solution for the fintech domain. It is believed that the widespread adoption and application of the Merkle-Transformer model will greatly advance innovation in the financial industry and lay a solid foundation for future research on secure financial data processing.
Kazunori Takahashi, Christine Charles, Rod W. Boswell
Measurement of an internal azimuthal plasma current in a collisionless low β plasma expanding in a magnetic nozzle is presented. The electric field is removed from the plasma ensuring a negligible electron E×B drift resulting in a purely diamagnetic electron azimuthal current. The electron energy probability function is non-Maxwellian, having an energetic tail component in addition to the thermal bulk electrons. The measured azimuthal current is significantly larger than the electron diamagnetic current estimated by considering only the bulk electrons. This can be well explained by considering the energetic tail electrons, which have a density of only about five percent of the total density. These results experimentally demonstrate that the energetic tail electrons are major contributors to the diamagnetism of the plasma even if their density is a small fraction of the total electron density.
Soonil Hong, Byoungwook Park, Chandran Balamurugan
et al.
Efforts to commercialize organic solar cells (OSCs) by developing roll-to-roll compatible modules have encountered challenges in optimizing printing processes to attain laboratory-level performance in fully printable OSC architectures. In this study, we present efficient OSC modules fabricated solely through printing methods. We systematically evaluated the impact of processing solvents on the morphology of crucial layers, such as the hole transport, photoactive, and electron transport layers, applied using the doctor blade coating method, with a particular focus on processability. Notably, deposition of charge transport layer using printing techniques is still a challenging task, mainly due to the hydrophobic characteristic of the organic photoactive layer. To overcome this issue, we investigated the solvent effect of a well-studied cathode interlayer, bathocuproine (BCP). We were able to form a uniform thin BCP film (∼10 nm) on a non-fullerene based organic photoactive layer using the doctor bladed coating method. Our results showed that the use of volatile alcohols in the BCP processing required a delicate balance between wettability and vaporization, which contrasted with the results for spin-coated films. These findings provide important insights into improving the efficiency of printing techniques for depositing charge transport layers. The fully printed OSC modules, featuring uniform and continuous BCP layer formation, achieved an impressive power conversion efficiency of 10.8% with a total area of 10.0 cm2 and a geometrical fill factor of 86.5%.
Vasilis Belis, Patrick Odagiu, Thea Klæboe Årrestad
The detection of out-of-distribution data points is a common task in particle physics. It is used for monitoring complex particle detectors or for identifying rare and unexpected events that may be indicative of new phenomena or physics beyond the Standard Model. Recent advances in Machine Learning for anomaly detection have encouraged the utilization of such techniques on particle physics problems. This review article provides an overview of the state-of-the-art techniques for anomaly detection in particle physics using machine learning. We discuss the challenges associated with anomaly detection in large and complex data sets, such as those produced by high-energy particle colliders, and highlight some of the successful applications of anomaly detection in particle physics experiments.
Abstract In this study, a novel coupling structure based on half‐mode substrate‐integrated waveguide (HMSIW) is proposed with a small size and broad bandwidth. The HMSIW coupler is realised by connecting their equivalent magnetic walls with metal strips, which avoids exposing the semi‐enclosed magnetic walls outside. Hence, it has greater anti‐interference capability than the existing HMSIW couplers. The directional coupling principle is introduced by analysing the proposed single connecting strip coupler. In order to lower return loss and higher isolation, a 3 dB directional coupler working from 10.8 to 16.8 GHz is designed with two connecting strips. Finally, a six‐port circuit is achieved by utilising this compact 3 dB directional coupler. Furthermore, a broadband HMSIW power divider is optimised to satisfy the performance of this six‐port circuit. The proposed coupler with metal strips helps to increase bandwidth and reduce size, which makes it more applicable to demanding systems with complex requirements such as detecting and transceiver systems. The 3 dB coupler and six‐port circuit are fabricated and measured. The measured results are in accordance with the simulated data.
The demand for the condition monitoring of induction motors is increasing in various fields, such as industry, transportation, and daily life. Bearing faults are the most common faults, and many fault diagnosis methods have been proposed using artificial pitting as the fault factor in most cases. However, the validity of a fault diagnosis method for other kinds of faults does not seem to be evaluated. Considering onsite scenarios and other possibilities of faults, this paper introduces scratches on the outer raceways of bearings. A study was performed on the detection of several kinds of bearing scratches using a proposed method that was based on an auto-tuning convolutional neural network. The developed approach was also compared with other diagnostic methods for validation. The results showed that the proposed technique provides the possibility of diagnosing several kinds of scratches with acceptable accuracy rates.
Defining interdisciplinary physics today requires first a reformulation of what is physics today, which in turn calls for clarifying what makes a physicist. This assessment results from my forty year journey arguing and fighting to build sociophysics. My view on interdisciplinary physics has thus evolved jumping repeatedly to opposite directions before settling down to the following claim: today physics is what is done by physicists who handle a problem the "physicist's way". However the training of physicists should stay restricted to inert matter. Yet adding a focus on the universality of the physicist approach as a generic path to investigate a topic. Consequently, interdisciplinary physics should become a cabinet of curiosities including an incubator. The cabinet of curiosities would welcome all one shots papers related to any kind of object provided it is co-authored at least by one physicist. Otherwise the paper should uses explicitly technics from physics. In case a topic gets many papers, it would be moved to the incubator to foster the potential emergence of a new appropriate subfield of physics. A process illustrated by the subsection social physics in Frontiers in physics.
This article describes reflections on the Fifth International Conference on Women in Physics which was a conference attended by 215 female physicists and a few male physicists from 49 different countries. The article focuses on the barriers that women face in their professional advancement in physics and the extent to which the situation is different in various countries.
To date, there is a lack of research on learning environments for pre-service physics teachers that allow them to learn and practise diagnosing students' conceptions that are (currently) not covered in physics education textbooks (e.g. students' conceptions about viscosity). In this study, we developed and piloted such a learning environment, which was implemented and piloted twice in a seminar for pre-service physics teachers. As coping with a diagnostic process is particularly demanding for pre-service physics teachers, our accompanying research aims to identify learning barriers within our developed learning environment. The results indicate that the participants experience the learning environment with varying degrees of difficulty. One main difficulty for pre-service physics teachers seems to be in interconnecting their content knowledge with their pedagogical content knowledge in the diagnostic process.
This paper presents a double sky-hook algorithm for controlling semi-active suspension systems in order to improve road-holding property for application in an in-wheel motor. The main disadvantage of the in-wheel motor is the increase in unsprung masses, which increases after shaking of the wheel, so it has poor road-holding that the conventional theoretical sky-hook algorithm cannot achieve. The double sky-hook algorithm uses a combination of damper coefficients, one from the chassis motion and the other from the wheel motion. Computer simulations using a quarter and full car dynamic models with the road conditions specified by ISO2631 showed the effectiveness of the algorithm. It was observed that the algorithm was the most effective in the vicinity of the wheel hop frequency. This paper also proposed the parameter set of the double sky-hook algorithm to differentiate the driving mode of vehicles under advanced development.
With the increase in the availability of multitemporal hyperspectral images (HSIs), HSIs change detection (CD) methods, including pixel-level and subpixel-level based methods, have attracted great attention in recent years. However, the widespread presence of mixed pixels in HSIs may make it difficult for pixel-level methods to detect subtle changes; meanwhile, the less utilization of spatial information may also lead to limitations in some subpixel-level methods. Therefore, a joint framework, which aims to combine the advantages of pixel-level in spatial utilization and subpixel-level in temporal and spectral exploration, is proposed to enhance the performance of HSIs CD. Two models, convolutional sparse analysis and temporal spectral unmixing, are introduced and presented to characterize different spatial structures and overcome the effects of spectral variability under this framework, respectively. In addition, a multiple CD-based on subpixel analysis is discussed as well. Experiments conducted on three bitemporal HSIs datasets indicate that the proposed framework is robust in capturing effective features and has achieved great detection accuracy.
The China Fusion Engineering Test Reactor (CFETR) and the Huazhong Field Reversed Configuration (HFRC), currently both under intensive physical and engineering designs in China, are the two major projects representative of the low-density steady-state and high-density pulsed pathways to fusion. One of the primary tasks of the physics designs for both CFETR and HFRC is the assessment and analysis of the magnetohydrodynamic (MHD) stability of the proposed design schemes. Comprehensive efforts on the assessment of MHD stability of CFETR and HFRC baseline scenarios have led to preliminary progresses that may further benefit engineering designs.
Recently, spacing policies of the vehicular platoon have been widely developed to enhance safety, traffic efficiency, and fuel consumption. However, the integrated spacing policies aim to maximum overall benefit, and the distributed spacing policies intense to get optimal monomer benefit. Ignoring the fairness of the benefit allocation of each vehicle will reduce the motivation to constitute the platoon. To fill this critical gap, this study proposes a spacing allocation method by treating spacing decisions as cooperative games. A flock’s model which is used to be the payoff function is introduced based on bionic motion principles. We present a characteristic function of the platoon for the cooperative game model considering the specific structure of the platoon. The τ value, Shapley value, and average lexicographic value are introduced and applied to allocate the spacing fairly. Proposed methods are compared with constant distance policy in some typical situations. The simulation results demonstrate that the spacing policy based on cooperative game theory improved the stable time for consistency control and the convergence of longitudinal following error.
A review is given on the foundations and applications of non-Hermitian classical and quantum physics. First, key theorems and central concepts in non-Hermitian linear algebra, including Jordan normal form, biorthogonality, exceptional points, pseudo-Hermiticity and parity-time symmetry, are delineated in a pedagogical and mathematically coherent manner. Building on these, we provide an overview of how diverse classical systems, ranging from photonics, mechanics, electrical circuits, acoustics to active matter, can be used to simulate non-Hermitian wave physics. In particular, we discuss rich and unique phenomena found therein, such as unidirectional invisibility, enhanced sensitivity, topological energy transfer, coherent perfect absorption, single-mode lasing, and robust biological transport. We then explain in detail how non-Hermitian operators emerge as an effective description of open quantum systems on the basis of the Feshbach projection approach and the quantum trajectory approach. We discuss their applications to physical systems relevant to a variety of fields, including atomic, molecular and optical physics, mesoscopic physics, and nuclear physics with emphasis on prominent phenomena/subjects in quantum regimes, such as quantum resonances, superradiance, continuous quantum Zeno effect, quantum critical phenomena, Dirac spectra in quantum chromodynamics, and nonunitary conformal field theories. Finally, we introduce the notion of band topology in complex spectra of non-Hermitian systems and present their classifications by providing the proof, firstly given by this review in a complete manner, as well as a number of instructive examples. Other topics related to non-Hermitian physics, including nonreciprocal transport, speed limits, nonunitary quantum walk, are also reviewed.
Physics is formulated in terms of timeless classical mathematics. A formulation on the basis of intuitionist mathematics, built on time-evolving processes, would offer a perspective that is closer to our experience of physical reality.