bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexible Krylov methods for group sparsity regularization
Authors: Chung Julianne , Sabaté Landman Malena 
Published: October 2024

Abstract
This paper introduces new solvers for efficiently computing solutions to large-scale inverse problems with group sparsity regularization, including both non-overlapping and overlapping groups. Group sparsity regularization refers to a type of structured sparsity regularization, where the goal is to impose additional structure in the regularization process by assigning variables to predefined groups that may represent graph or network structures. Special cases of group sparsity regularization include ℓ
1 and isotropic total variation regularization. In this work, we develop hybrid projection methods based on flexible Krylov subspaces, where we first recast the group sparsity regularization term as a sequence of 2-norm penalization terms using adaptive regularization matrices in an iterative reweighted norm fashion. Then we exploit flexible preconditioning techniques to efficiently incorporate the weight updates. The main advantages of these methods are that they are computationally efficient (leveraging the advantages of flexible methods), they are general (and therefore very easily adaptable to new regularization term choices), and they are able to select the regularization parameters automatically and adaptively (exploiting the advantages of hybrid methods). Extensions to multiple regularization terms and solution decomposition frameworks (e.g. for anomaly detection) are described, and a variety of numerical examples demonstrate both the efficiency and accuracy of the proposed approaches compared to existing solvers.
Self-diffusion in Germanium-rich liquid Germanium-Nickel investigated by quasielastic neutron scattering
Authors: Weis H , Kargl F , Yang F , Unruh T , Koza M M , Meyer A 
Published: October 2024

Abstract
We report atomic dynamics in liquid Ge98Ni2 measured using quasielastic neutron scattering. Isotopic substitution enabled to separately determine Ge and Ni self-diffusion with high accuracy. The Ge self-diffusion coefficient in liquid Ge98Ni2 is equal within error bars to that in pure liquid Ge. However, the Ni self-diffusion coefficient lies at least 30% below the Ge self-diffusion coefficient. This behaviour differs from previously reported atomic dynamics in Ge-rich GeAu, GeSi, GeIn and GeCe melts, where no separation of the self-diffusion coefficients between the minor component and Ge is observed. The change of the atomic dynamics already at an addition of 2 at% Ni points to electronic and chemical origins in Ge98Ni2. Moreover, the slower self-diffusion of the minor component compared to Ge might be associated with two different local structural environments, as observed in Ge-Ni alloys at higher Ni concentration.
A quad-polarization reconfigurable transmitarray antenna with beam-scanning and reconfigurable polarization capabilities
Authors: Tian Xiuwen , Song Lizhong 
Published: October 2024

Abstract
In this paper, a novel quad-polarized electronically reconfigurable transmitarray antenna(QRTA) is proposed, which can actively switch among four linear-polarization modes and steer beam-scanning in these polarization modes. The QRTA element follows a receiving-transmitting structure. Its receiver or transmitter is composed of four rotationally symmetric patches and a coupling patch. Four rotationally symmetric patches generate x- and y-polarization modes, while coupling patches on the top and bottom layers of the QRTA element are designed to synthesize x-, 45◦-, y-, and 135◦-polarization modes. The QRTA element utilizes a reverse symmetry current method to achieve a 180◦ phase difference in the radiated electromagnetic waves. By manipulating the state of the p-i-n diodes, the proposed QRTA element can achieve four LP functions and a 1-bit phase shift. Based on the proposed novel QRTA element, a 10 × 10 elements QRTA prototype is fabricated and measured. The measured results demonstrate that the proposed QRTA can electronically switch between four LP modes and achieve beam-scanning in those LP modes. The proposed QRTA shows several advantages, including low cost, multi-polarization capability, high gain, and beam-scanning, which means that it can enhance the polarization capabilities and intelligence of wireless communication systems.
Effect of dark matter interaction on hybrid star in the light of the recent astrophysical observations
Authors: Pal Suman , Chaudhuri Gargi 
Published: October 2024

Abstract
We have explored the effect of dark matter interaction on hybrid star (HS) in the light of recent astrophysical observational constraints. The presence of dark matter is assumed to be there in both the hadron as well as the quark sector. The dark matter particle interacts with both hadron and quark matter through the exchange of a scalar as well as a vector meson. The equation of state (EOS) of the hadron part is computed using the NL3 version of the relativistic mean field(RMF) model, whereas the quark part is taken care of using the well-known MIT Bag model with the vector interaction. We investigate the effect of the dark matter density and the mass of the dark matter particle on various observables like mass, radius, tidal deformability of the dark matter admixed hybrid star(DMAHS).
In this study, we have noted an intriguing aspect that is the speed of sound in the DMAHS is insensitive to both the mass as well as the density of dark matter. We also observe a striking similarity in the variation of transition mass and its corresponding radius, as well as the maximum mass of neutron stars, with dark matter density and mass. We employ observational constraints from neutron stars to narrow down the allowed range of the parameters of dark matter.
Constraining burdened PBHs with gravitational waves
Authors: Barman Basabendu , Loho Kousik , Zapata Óscar 
Published: October 2024

AbstractWe investigate the implications of memory burden on the gravitational wave (GW) spectrum arising from the Hawking evaporation of light primordial black holes (PBHs). By considering both rotating (Kerr) and non-rotating (Schwarzschild) PBHs, we demonstrate that the overproduction of primordial GWs from burdened PBHs could impose stringent constraints on the parameters governing backreaction effects. These constraints, derived from ΔNeffmeasurements by Planck and prospective experiments such as CMB-S4 and CMB-HD, offer novel insights into the impact of memory burden on PBH dynamics.
Embedded Star Catalog Calculation Tool for Autonomous Star Trackers
Authors: Bürger Karoline C. , Fialho Fábio de O. , Aykroyd Christopher R. B. 
Published: October 2024

Abstract
Autonomous star trackers are crucial attitude sensors for spacecraft three-axis control. They are the most accurate commercial-off-the-shelf sensors available. An autonomous star tracker is an optoelectronic device that autonomously determines the spacecraft’s attitude, using an embedded star catalog that is compared to in-orbit images to perform stellar field recognition. This work presents a computational tool to calculate the embedded star catalog for any specified star sensor. To optimize the star sensor design, the tool developed provides users with sensor accuracy analysis regarding the observed starfield.
Identification of Z Cam's Historical Counterpart: The Quest for an Ancient Nova
Authors: Yang Bo-Shun , Hoffmann Susanne M. 
Published: October 2024

Abstract
In recent astronomical discussions, attempts have been made to link the known dwarf nova Z Cam to historical celestial events, particularly the “guest star” phenomenon reported in China in 77 BCE. Despite other suggestions and the problems with regard to the location of the event in 77 BCE, its identification with Z Cam is used in the Variable Star Index of the AAVSO and in several research papers that aim to derive knowledge on the evolution of cataclysmic variables. Through the reconstruction of the super-constellation of the Purple Palace in the Han Dynasty, we found that Z Cam is actually located outside this enclosure, contradicting the records of the 77 BCE guest star being “within the Purple Palace.” With newly found text versions of the guest star in 77 BCE, we narrowed down the position given therein. Combining with a new analysis of accompanying divination text leads to the conclusion that this guest star was actually a comet. Finally, through meticulous examination and comparison, we conclude that the guest star of 369 CE appears the most plausible candidate for Z Cam’s historical counterpart, aligning with both textual evidence and modern astronomical observations.
Saddle-to-saddle dynamics in diagonal linear networks*
Authors: Pesme Scott , Flammarion Nicolas 
Published: October 2024

Abstract
In this paper we fully describe the trajectory of gradient flow over two-layer diagonal linear networks for the regression setting in the limit of vanishing initialisation. We show that the limiting flow successively jumps from a saddle of the training loss to another until reaching the minimum

ℓ
1

-norm solution. We explicitly characterise the visited saddles as well as the jump times through a recursive algorithm reminiscent of the LARS algorithm used for computing the Lasso path. Starting from the zero vector, coordinates are successively activated until the minimum

ℓ
1

-norm solution is recovered, revealing an incremental learning. Our proof leverages a convenient arc-length time-reparametrisation which enables to keep track of the transitions between the jumps. Our analysis requires negligible assumptions on the data, applies to both under and overparametrised settings and covers complex cases where there is no monotonicity of the number of active coordinates. We provide numerical experiments to support our findings.
Research on cooperative game optimization scheduling of multi-micro-networks considering carbon trading
Authors: An Yinping , Meng Xiangping , Jia Youbo , Cheng Yue , Liu Fang 
Published: October 2024

Abstract
Developing a clean, low-carbon, secure, and efficient energy system based on dual carbon and transitioning to a new energy-dominated power system is a crucial step for China’s energy evolution and path to carbon neutrality. This study examines multi-microgrid collaboration under carbon trading to encourage local energy consumption and drive the operation of a low-carbon economy. A cooperative game strategy-based scheduling approach is proposed. Initially, the operational framework for a multi-microgrid system with carbon capture capability is defined, along with a model for low-carbon operation across multiple energy sources. Subsequently, power trading is facilitated within and between sub-microgrids and distribution networks to enhance the economic viability of the multi-microgrid setup. The study outlines the multi-microgrid system, presents typical power supply models, introduces the core concept of cooperative games, and establishes a grid-connected multi-microgrid scheduling cooperative game model. The ADMM algorithm is employed to address cost minimization and benefit maximization challenges within the multi-microgrid alliance. The efficacy of this strategy is evidenced through a numerical illustration.
Application of model predictive control scheme for piezoelectric ceramic micro-displacement
Authors: Kang Dianyu , Xue Wei , Hu Siqi , Xiao Jing 
Published: October 2024

Abstract
Currently, in the domain of micro-control technology, many operations need to meet the standard of nanometer-level positioning. As a high-precision micro-displacement element, piezoelectric ceramics are widely used in the field of micro-control due to their characteristics such as no need for transmission devices, high resolution, large output force, small size, and fast response speed. However, the inherent hysteresis nonlinearity of piezoelectric ceramics can lead to decreased displacement accuracy, oscillation, and even system instability. Therefore, eliminating the influence of nonlinear characteristics and improving displacement accuracy possess significant practical importance. In this paper, a model predictive control scheme is designed, which achieves faster response speed and higher accuracy compared to traditional control methods such as Proportional Integral Derivative control. Relevant simulations and tests have been conducted. In this scheme, hysteresis nonlinearity is first modeled and then compensated through feedforward, thereby simplifying the displacement control of piezoelectric ceramics into a more manageable linear problem. Subsequently, a linear model predictive control method is adopted to control the entire system. Both simulation and experimental results have verified the effectiveness of this control method.
Process optimization of wet etching for split gate trench MOSFET
Authors: Xi Lan Chen , Jin Chao , Gong Yu Bing , Li Wang Hong , Fan Li Ping 
Published: October 2024

Abstract
In this paper, the influence of etching technology on the performance of Split Gate Trench (SGT) MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor) is studied, and the significance and contribution of these improvements in the fields of mechatronics, robotics and control systems are discussed. Etching can be categorized into wet etching and dry etching, with wet etching being widely used for etching the gates of SGT MOSFETs. Due to the isotropic nature of wet etching, issues such as undercutting, trenching, and insufficient link-up region length can arise, leading to short circuits between the gate and the source. The improvement of this problem directly promotes the enhancement of mechatronics system efficiency, the improvement of robot dynamic performance and accuracy, and the realization of efficient control strategies in control systems. By optimizing the process flow to enhance the adhesion of photoresist, increase the density of the HDP (High Density Plasma) deposited oxide film, and adjust the etching rate and frequency of wet etching, it is possible to mitigate the issues of isotropy and insufficient precision in wet etching. These improvements address failure phenomena and enhance product yield.
Characteristic analysis of rain-wind induced stay-cable vibration based on friction damper in field observation
Authors: Wu Xiaoxi 
Published: October 2024

Abstract
Both domestic and foreign scholars have developed various friction dampers with good characteristics. The primary types of friction dampers include conventional friction dampers, Pall friction dampers, Sumitomo friction dampers, and Centripetal friction dampers. The components of these dampers will slip or deform under load effect when the energy is consumed by friction. As the structural vibration period increases while the external energy input decreases, the vibration amplitude is reduced. This vibration reduction method is widely used in the automotive industry. Most of the hysteresis models of dampers are similar to rectangular shapes, making the selection of an accurate initial sliding force crucial for the rectangular hysteresis model. Based on the effective data collected from the field observation test, a self-made friction damper, which has a good vibration reduction effect, was used to observe rain-wind induced stay-cable vibration at Dongting Lake Bridge in Yueyang, Hunan Province. Accordingly, some suggestions are put forward for the research work on rain-wind-induced vibration.
Research on smoke cleaning based on Mg(OH)2/NaClO2 seawater solution
Authors: Guo Xu , Lu Yulei , Gong Xiwu 
Published: October 2024

Abstract
Ship exhaust emissions contain a large amount of sulfur oxides and nitrogen oxides, which have attracted widespread attention from the international community for their pollution of the atmospheric environment. In order to reduce the emissions of these pollutants, the International Maritime Organization (IMO) and other national institutions have established strict emission standards and promoted the research and application of ship exhaust desulfurization and denitrification technology. Experimental and simulation analyses were conducted on the denitrification effect of Mg(OH)2/NaClO2 solution using a cyclic spray method. Simulation analysis was carried out using cyclic spraying. The experiment compared the reaction degree and reaction time of NO in NaClO2 seawater, NaClO2 water, and Mg(OH)2/NaClO2 marine solution. The experimental result is that in the process of cyclic spray, the removal rate of NO by these three solutions can reach 100%. The reaction time of NO is 71, 86, and 90 minutes, respectively. Under the same conditions, the simulation results showed that the reaction rate of NaClO2 water solution with NO was faster, followed by NaClO2 seawater solution. The reaction rate of Mg(OH)2/NaClO2 seawater solution with NO was the slowest of the three. When the pH value exceeds 7, it effectively inhibits the production of ClO2 gas by NaClO2. The removal rate of Mg(OH)2/NaClO2 seawater solution is directly proportional to the initial concentration of NaClO2. In addition, it could be seen from the simulation cloud diagram that the removal speed of NO in the spray reactor slows down as the concentration of NO increases.
Simulation study on submarine trench gravel dumping under the influence of hydrodynamics
Authors: Wang Xiaohua , Zhu Ping , Jiang Yonghui 
Published: October 2024

Abstract
Gravel drift under the hydrodynamic effect is a significant problem during gravel dumping operations in coastal areas, which has a great impact on construction efficiency. Based on the Zhangpu submarine pipeline project, this paper investigated the drift distance and underwater distribution characteristics of gravel during the process of submarine trench gravel dumping under the influence of hydrodynamics by using the computational fluid dynamics (CFD) method. The results show that the greater the water depth and current speed is, the farther the drift distance of gravel along the current direction is. The water current has the most significant effect on the underwater distribution of gravel. The larger the current velocity is, the larger the underwater distribution width of gravel after sinking to the bottom is, and the larger the loss rate of gravel which has not been thrown to the required range is. The construction work should be avoided under high current speed conditions when carrying out gravel dumping.
Ship hydrodynamic performance analysis and model construction based on CFD method
Authors: Zhang Hangming , Zhang Yongtao 
Published: October 2024

Abstract
CFD method has the advantages of high forecast accuracy, wide applicability, strong stability of calculation results, and low cost, and nowadays it has been widely used in various fields. The CFD method has many advantages when applied to ship hydrodynamic performance analysis, specifically to ship hydrodynamic performance prediction, problem mechanism research, and performance optimization. Based on this, this paper utilizes the CFD method to carry out a model analysis of ship hydrodynamic performance. By analyzing the propeller efficiency, the reasoning force and torque of the double propeller in the symmetric case are decreased. However, the efficiency is improved by 1.4% compared with the asymmetric case, which shows that the method adopted in this paper can effectively improve the ship hydrodynamic force. Through the above research, we aim to provide a certain reference for the improvement of ship hydrodynamic performance.
Resistance performance study and hull form optimization of aquaculture vessel by CFD method
Authors: Tao Yanwu , Zhu Renqing , Gu Jiayang , Li Zhiyu 
Published: October 2024

Abstract
Aquaculture vessel is a novel form of deep-sea aquaculture engineering with a wide range of applications. The resistance performance of the aquaculture vessel was studied by the computational fluid dynamics method and compared with the experiment. Two optimization schemes, namely, straight bow and bulbous bow, are designed to optimize the original design, focusing on improving the bow profile. The effectiveness of the two optimization schemes in terms of resistance reduction was evaluated by the CFD method. The resistance calculated by numerical calculations was found to be in good agreement with the experimental results. The bulbous bow scheme reduces resistance better than the upright scheme, with a resistance reduction of 2.92% at 11 kn. This study can guide the overall design of an aquaculture vessel.
Research and application of the method of measuring the effective utilization coefficient of irrigation water on farmland
Authors: Fan Qunfang , Long Xiaofei , Wang Xinghan , Guo Wei 
Published: October 2024

Abstract
Under the guidance of the new water management idea of “water conservation priority, spatial balance, system management, and two-handed effort,” the National Water Conservation Action Plan released in 2019 puts forward the key task requirements of “double control of total intensity,” in which the effective utilization coefficient of irrigation water in farmland is one of the indicators of water intensity control. The effective utilization coefficient of irrigation water is one of the water intensity control indicators. At present, there are practical difficulties in measuring the effective utilization coefficient of irrigation water in farmland, such as the low measurement rate of water consumption in the current irrigation area, the high input equipment and manpower requirements, and the difficulty in accurately measuring the net irrigation water absorbed by crops. Therefore, this paper proposed the method of “field monitoring - remote sensing inversion - a comprehensive analysis of data.” The method of “field monitoring - remote sensing inversion - econometric model construction - comprehensive analysis” was proposed in this paper, which can obtain gross irrigation water utilizing field monitoring, overcome the difficulty of accurate monitoring of net irrigation water using remote sensing, and carried out a comprehensive analysis, to realize the scientific, effective and rapid calculation of effective utilization coefficient of irrigation water. This method was applied to the Meixian District, Guangdong Province, and the research results show that it not only generates reliable measurement data but also alleviates workload. Furthermore, it offers scientific measurement techniques for water use efficiency indicators, facilitating the achievement of “dual control over total volume and intensity.” This paper provides an important technical basis for the rational allocation of water consumption and scientific approval of water use plans and supports the assessment of the effectiveness of water-saving irrigation development and the reasonable evaluation of the water-saving potential of farmland irrigation, thus providing a basis for local government departments at all levels to make planning, scientific decision-making, and macro-management.
Identifying faults in UHVDC transmission systems using DAE and ensemble learning
Authors: Guo Yiheng , Zhao Qingshen , Liang Dingkang 
Published: October 2024

Abstract
The current fault identification technique for the ultra high voltage direct current transmission system has a low success rate, the process of extracting feature qualities is complex, and it is difficult to identify high resistance grounding. This research provides a defect evaluation method for UHVDC transmission system using Deep Auto Encoder (DAE) and integrated learning. Firstly, the fault voltage signal is feature extracted using DAE, and then, a series of obtained features are feature screened by XGBoost algorithm and combined with an integrated classifier consisting of Multi-Layer Perceptron (MLP), K Nearest Neighbor (KNN), and Random Forest (RF) classifiers to identify the UHVDC faults. Finally, ±800kV UHVDC transmission line models are established in MATLAB/Simulink simulation software to simulate different types of faults. The study’s findings demonstrate that the fault diagnostic method introduced in this research may significantly enhance the poor detection success rate of current fault diagnostics methods and is more resilient to excessive resistance.