bluuebunny/crossref_metadata_2025 huggingface dataset:
Are Goodwill Ambassadors Good for Business? The Impact of Celebrities on International Organization Fundraising
Authors: Malik Rabia , Thorvaldsdottir Svanhildur
Published: August 2024

Many international organizations (IOs) rely on voluntary contributions from member states and private actors to fund their operations. Donations from individuals are a significant and increasing income source for these IOs, who rely on marketing strategies such as celebrity endorsement, in the form of Goodwill Ambassadors, to help raise funds. Little is known, however, about the effectiveness of this strategy in the context of IOs although intuition from literatures in marketing and psychology suggests that celebrity endorsement should be effective. We conduct a survey experiment to investigate the effectiveness of Goodwill Ambassadors and, contrary to expectations, find no average effect of celebrity endorsement on donations to, and interest in, IOs and only limited effects among certain sub-groups. We speculate that the context of IOs makes it harder to generate the type of connection between celebrity and cause necessary to make endorsement effective and suggest that further investigation is needed.
Neutrophil extracellular traps mediate the crosstalk between plaque microenvironment and unstable carotid plaque formation
Authors: Cao Yu , Chen Minghui , Jiao Xinyu , Li Shuijie , Wang Dong , Zhan Yongxuan , Li Jiaju , Hao Zhongfei , Li Qingbin , Liu Yang , Feng Yan , Li Ruiyan , Wang Hongjun , Liu Mingli , Fu Qiang , Li Yongli
Published: August 2024

The development of unstable carotid atherosclerotic plaques is associated with the induction of neutrophil extracellular traps (NETs) via the activation of diverse inflammatory mediators in the circulating bloodstream. However, the underlying mechanisms through which NETs influence the microenvironment of atherosclerotic plaques and contribute to the development of unstable carotid plaques remain largely elusive. The objective of this study was to elucidate the role of myeloid differentiation protein 1 (MD-1, LY86)-induced NETs underlying the crosstalk between unstable plaque formation and the plaque microenvironment. We employed bioinformatics analysis to identify key genes associated with carotid-unstable plaque, followed by comprehensive validation using various experimental approaches on tissue specimens and plasma samples classified based on pathological characteristics. Patients with carotid-unstable plaques exhibited elevated plasma concentrations of MD-1 (LY86), while patients with stable plaques demonstrated comparatively lower levels. Furthermore, soluble MD-1 was found to induce the formation of NETs through activation of Toll-like receptor signaling pathway. The proliferative and immature vascularization effects of NETs on endothelial cells, as well as their inhibitory impact on cell migration, are directly correlated with the concentration of NETs. Additionally, NETs were found to activate the NF-κB signaling pathway, thereby upregulating ICAM1, VCAM1, MMP14, VEGFA, and IL6 expression in both Human umbilical vein endothelial cells (HUVECs) and HAECs. Subsequently, a significant increase in intraplaque neovascularization by NETs results in poor carotid plaque stability, and NETs in turn stimulate macrophages to produce more MD-1, generating a harmful positive feedback loop. Our findings suggest that soluble MD-1 in the bloodstream triggers the production of NETs through activation of the Toll-like receptor signaling pathway and further indicate NETs mediate a crosstalk between the microenvironment of the carotid plaque and the neovascularization of the intraplaque region. Inhibiting NETs formation or MD-1 secretion may represent a promising strategy to effectively suppress the development of unstable carotid plaques.
A global annual fractional tree cover dataset during 2000–2021 generated from realigned MODIS seasonal data
Authors: Liu Yang , Liu Ronggao , Chen Jilong , Wei Xuexin , Qi Lin , Zhao Lei
Published: August 2024

Fractional tree cover facilitates the depiction of forest density and its changes. However, it remains challenging to estimate tree cover from satellite data, leading to substantial uncertainties in forest cover changes analysis. This paper generated a global annual fractional tree cover dataset from 2000 to 2021 with 250 m resolution (GLOBMAP FTC). MODIS annual observations were realigned at the pixel level to a common phenology and used to extract twelve features that can differentiate between trees and herbaceous vegetation, which greatly reduced feature dimensionality. A massive training data, consisting of 465.88 million sample points from four high-resolution global forest cover products, was collected to train a feedforward neural network model to predict tree cover. Compared with the validation datasets derived from the USGS circa 2010 global land cover reference dataset, the R2 value, MAE, and RMSE were 0.73, 10.55%, and 17.98%, respectively. This dataset can be applied for assessment of forest cover changes, including both abrupt forest loss and gradual forest gain.
The $$^{146}\text{Sm}$$ half-life re-measured: consolidating the chronometer for events in the early Solar System
Authors: Chiera Nadine M. , Sprung Peter , Amelin Yuri , Dressler Rugard , Schumann Dorothea , Talip Zeynep
Published: August 2024

The half-life of the extinct radiolanthanide $$^{146}\text{Sm}$$

146

Sm

, important for both geochronological and astrophysical applications, was re-determined by a combination of mass spectrometry and $$\alpha$$
α
-decay counting. Earlier studies provided only limited information on all potential factors that could influence the quantification of the half-life of $$^{146}\text{Sm}$$

146

Sm

. Thus, special attention was given  here to a complete documentation of all experimental steps to provide information about any possible artifacts in the data analysis. The half-life of $$^{146}\text{Sm}$$

146

Sm

was derived to be 92.0 Ma ± 2.6 Ma, with an uncertainty coverage factor of $$\mathsf{\textit{k}\!=\!1}$$

k

=

1

.
Skin cancer detection through attention guided dual autoencoder approach with extreme learning machine
Authors: Maurya Ritesh , Mahapatra Satyajit , Dutta Malay Kishore , Singh Vibhav Prakash , Karnati Mohan , Sahu Geet , Pandey Nageshwar Nath
Published: August 2024

Skin cancer is a lethal disease, and its early detection plays a pivotal role in preventing its spread to other body organs and tissues. Artificial Intelligence (AI)-based automated methods can play a significant role in its early detection. This study presents an AI-based novel approach, termed 'DualAutoELM' for the effective identification of various types of skin cancers. The proposed method leverages a network of autoencoders, comprising two distinct autoencoders: the spatial autoencoder and the FFT (Fast Fourier Transform)-autoencoder. The spatial-autoencoder specializes in learning spatial features within input lesion images whereas the FFT-autoencoder learns to capture textural and distinguishing frequency patterns within transformed input skin lesion images through the reconstruction process. The use of attention modules at various levels within the encoder part of these autoencoders significantly improves their discriminative feature learning capabilities. An Extreme Learning Machine (ELM) with a single layer of feedforward is trained to classify skin malignancies using the characteristics that were recovered from the bottleneck layers of these autoencoders. The 'HAM10000' and 'ISIC-2017' are two publicly available datasets used to thoroughly assess the suggested approach. The experimental findings demonstrate the accuracy and robustness of the proposed technique, with AUC, precision, and accuracy values for the 'HAM10000' dataset being 0.98, 97.68% and 97.66%, and for the 'ISIC-2017' dataset being 0.95, 86.75% and 86.68%, respectively. This study highlights the possibility of the suggested approach for accurate detection of skin cancer.
On detailed representation of flood defences and flow-wave coupling in coastal flood modelling
Authors: Duong Trang Minh , Meynadier Remi , Ranasinghe Roshanka , Loaiza Manuel Andres Diaz , Bricker Jeremy D. , Reyns Johan , Luijendijk Arjen , Bamunawala Janaka
Published: August 2024

Coastal flooding is projected to become more severe over the 21st century, necessitating effective adaptation, which in turn requires detailed local scale information that can only be provided by detailed numerical modelling. The current lack of information on flood protection measures and the high resource requirements of traditional hydrodynamic models presents concurrent challenges for detailed coastal flood modelling. But how comprehensive do the representation of coastal flood defences and hydrodynamic forcing need to be for adequately accurate modelling of coastal flooding? Here, we attempt to answer this question through strategic numerical simulations of the flooding that occurred at Île de Ré (France) during the Xynthia storm (2010), using the flexible mesh model Delft3D FM, with an over-land grid resolution of ~10 m. The model is validated against the flood extents observed in Île de Ré during Xynthia. We use three levels of detail in flood defence representation: a 5 m resolution DEM (i.e. base case DEM), the same 5 m DEM augmented with defences extracted from a 1 m DEM and Google Earth images (i.e. moderately augmented DEM), and the moderately augmented DEM further augmented with in-situ measurements of flood defences (i.e. highly augmented DEM). Simulations with these three DEMs are performed with and without flow-wave coupling (thus, 6 simulations in total), and results are analysed in terms of four flood indicators: maximum flood depths, flood extents, flood current velocities and flood damages. Our analysis indicates that both detailed representation of flood defences and the inclusion of waves have substantial effects on coastal flood modelling at local scale, with the former having a more pronounced effect. The return on the investment in implementing highly detailed in-situ measurements to represent flood defences appears to be low in this case, and adequately accurate results are obtained with a moderately augmented DEM. The combined effect of using the moderately augmented DEM together with waves, relative to using the base case DEM without waves, is to decrease maximum flood depths (up to 2 m), flood extent (by ~10%), maximum current velocities (in ~50% flooded area) and total flood damage (by ~27% or ~€ 188 million).
Comparison of cyclotron and synchrotron in particle therapy
Authors: Xiao Mei , Liu Bing , Peng Jingyu , Li Mindi , Xie Shuqing
Published: August 2024

Particle therapy utilizes high-energy protons and carbon ions to treat patients, leveraging their unique Bragg peak and superior relative biological effectiveness. This treatment modality shows great promise in improving disease cure rates and minimizing treatment side effects. However, its adoption in China is limited by the high cost associated with this advanced radiotherapy technique, highlighting a substantial demand for particle therapy equipment in the country. This report conducts a comparative analysis of cyclotron and synchrotron accelerators, prevalent in clinical particle therapy institutes. We examine their beam parameters and provide detailed insights into the techniques and functionalities associated with each accelerator type. Specifically, we elucidate the processes of beam injection, acceleration, and extraction, highlighting operational intricacies at each phase of the cycle. Furthermore, we present beam intensity and energy modulation for both accelerators in three-dimensional dose delivery. In summary, the synchrotron offers adjustable energy levels and the ability to produce high-energy multi-ions, while maintaining a high beam transmission rate. Conversely, the cyclotron provides continuous beams with rapid intensity modulation and an energy degrader on the beam transport line for energy variation, leading to activation near the degrader. Therefore, when selecting the most suitable accelerator for clinical institutes, factors such as cost, maintenance requirements, treatment efficiency, and clinical needs must be carefully considered.
Heart of the future home: a multidimensional model of inclusive kitchen for older people in the UK
Authors: Xu Zhidiankui , Bao Yixi , Dong Hua , Wu Yu , Tang Guyue
Published: August 2024

With the development of smart technology and aging societies, the living and housing environments for older people are undergoing transformation. Designers must understand the changing capabilities, lifestyles, preferences, and inspirations of older people for their future homes, in which the kitchen is seen as the heart. To gain a deeper understanding of the requirements of older people in promoting healthier lifestyles and inclusive daily practices, the authors identified five key factors of kitchen design through a literature review, developing an initial model. Subsequently, a focus group was conducted in the UK to explore the perspectives and expectations of older people, where metaphors for future kitchens were collected, and further insights were used to refine the model. The refined model for a future-inclusive kitchen encompasses six dimensions: Environment/space, Technology/interaction, Emotion/affect, Health and safety, Human factors and well-being, and Sustainability. Through using metaphors, this study offers a multidimensional lens to investigate the future user experience of inclusive kitchens. The significance of this study lies in the originality of combining a literature review, and user study with design metaphors. A future-proof inclusive kitchen design model is proposed to provide guidance for future design directions of age-friendly environments.
How to make a midsize black hole
Authors: Fattaruso Laura
Published: August 2024

Detailed simulations of star formation show that runaway collisions in a giant molecular cloud could produce very massive stars that are precursors to intermediate-mass black holes.
The wonderland of angstrofluidics
Authors: Boya Radha , Keerthi Ashok , Parambath Muhammad Sajeer
Published: August 2024

Fluids confined to molecular-scale channels exhibit properties not seen on the macroscale. Research into angstrofluidics has only just begun to unlock the potential applications that the unique properties provide.
The tsunami triggered by the Chicxulub impact
Authors: Arbic Brian K. , Johnson Brandon C. , Titov Vasily
Published: August 2024

The large wave caused by the dinosaur-killing asteroid impact eroded the seafloor and disturbed sediments in ocean basins far from the collision site.
Five decades of missing matter
Authors: de Swart Jaco
Published: August 2024

Groups on both sides of the Iron Curtain hypothesized in the 1970s that a yet-unknown material makes up most of the mass in the universe.
Leveraging the full expertise of radiographers for improved healthcare delivery
Authors: Murphy Andrew , Neep Michael J.
Published: August 2024

The role of radiographers in healthcare has evolved significantly from operating imaging equipment to being essential in patient care and diagnosis. In Australia, radiographers play a crucial role in image interpretation, identifying and communicating significant findings to enhance patient outcomes. Preliminary image evaluation (PIE) allows radiographers to interpret images and ensure significant findings are noted, particularly in urgent situations, complementing diagnoses when radiologist reports are unavailable. Despite their potential, many radiographers lack empowerment, leading to delays and adverse patient outcomes. This underutilisation stems from a lack of support and systemic barriers. Radiographers, with their extensive expertise in imaging, are vital for ensuring patient safety and care quality. Policy changes are needed to integrate PIE into standard workflows, allowing radiographers to fully utilise their skills. Recognising and leveraging their expertise will enhance patient care, foster collaboration, and ensure radiographers contribute fully to the healthcare team, ultimately improving patient safety and care quality.
Australian sonographers – sound policy for progress?
Authors: Kipping Luke
Published: August 2024

What is known about the topic? Sonographers are well-known for their diagnostic roles in medical ultrasound though many have significant exposure to a range of interventional procedures. What does this paper add? Some sonographers are trained and qualified in these, including performing ultrasound-guided musculoskeletal injections. What are the implications for practitioners? A number of barriers exist for sonographers to use these skills to potential within the Australian healthcare system.
Canola (Brassica napus) enhances sodium chloride and sodium ion tolerance by maintaining ion homeostasis, higher antioxidant enzyme activity and photosynthetic capacity fluorescence parameters
Authors: Sun Lupeng , Cao Xiaoqiang , Du Juncan , Wang Yan , Zhang Fenghua
Published: August 2024

Under salt stress, plants are forced to take up and accumulate large amounts of sodium (Na+) and chloride (Cl−). Although most studies have focused on the toxic effects of Na+ on plants, Cl− stress is also very important. This study aimed to clarify physiological mechanisms underpinning growth contrasts in canola varieties with different salt tolerance. In hydroponic experiments, 150 mM Na+, Cl− and NaCl were applied to salt-tolerant and sensitive canola varieties. Both NaCl and Na+ treatments inhibited seedling growth. NaCl caused the strongest damage to both canola varieties, and stress damage was more severe at high concentrations of Na+ than Cl−. High Cl− promoted the uptake of ions (potassium K+, calcium Ca2+) and induced antioxidant defence. Salt-tolerant varieties were able to mitigate ion toxicity by maintaining lower Na+ content in the root system for a short period of time, and elevating magnesium Mg2+ content, Mg2+/Na+ ratio, and antioxidant enzyme activity to improve photosynthetic capacity. They subsequently re-established new K+/Na+ and Ca2+/Na+ balances to improve their salt tolerance. High concentrations of Cl salts caused less damage to seedlings than NaCl and Na salts, and Cl− also had a positive role in inducing oxidative stress and responsive antioxidant defence in the short term.
Convergent evolution in toxin detection and resistance provides evidence for conserved bacterial–fungal interactions
Authors: Dolan Stephen K. , Duong Ashley T. , Whiteley Marvin
Published: August 2024

Microbes rarely exist in isolation and instead form complex polymicrobial communities. As a result, microbes have developed intricate offensive and defensive strategies that enhance their fitness in these complex communities. Thus, identifying and understanding the molecular mechanisms controlling polymicrobial interactions is critical for understanding the function of microbial communities. In this study, we show that the gram-negative opportunistic human pathogen
Pseudomonas aeruginosa
, which frequently causes infection alongside a plethora of other microbes including fungi, encodes a genetic network which can detect and defend against gliotoxin, a potent, disulfide-containing antimicrobial produced by the ubiquitous filamentous fungus
Aspergillus fumigatus
. We show that gliotoxin exposure disrupts
P. aeruginosa
zinc homeostasis, leading to transcriptional activation of a gene encoding a previously uncharacterized dithiol oxidase (herein named as DnoP), which detoxifies gliotoxin and structurally related toxins. Despite sharing little homology to the
A. fumigatus
gliotoxin resistance protein (GliT), the enzymatic mechanism of DnoP from
P. aeruginosa
appears to be identical that used by A. fumigatus. Thus, DnoP and its transcriptional induction by low zinc represent a rare example of both convergent evolution of toxin defense and environmental cue sensing across kingdoms. Collectively, these data provide compelling evidence that
P. aeruginosa
has evolved to survive exposure to an
A. fumigatus
disulfide-containing toxin in the natural environment.
Codiscovering graphical structure and functional relationships within data: A Gaussian Process framework for connecting the dots
Authors: Bourdais Théo , Batlle Pau , Yang Xianjin , Baptista Ricardo , Rouquette Nicolas , Owhadi Houman
Published: August 2024

Most problems within and beyond the scientific domain can be framed into one of the following three levels of complexity of function approximation. Type 1: Approximate an unknown function given input/output data. Type 2: Consider a collection of variables and functions, some of which are unknown, indexed by the nodes and hyperedges of a hypergraph (a generalized graph where edges can connect more than two vertices). Given partial observations of the variables of the hypergraph (satisfying the functional dependencies imposed by its structure), approximate all the unobserved variables and unknown functions. Type 3: Expanding on Type 2, if the hypergraph structure itself is unknown, use partial observations of the variables of the hypergraph to discover its structure and approximate its unknown functions. These hypergraphs offer a natural platform for organizing, communicating, and processing computational knowledge. While most scientific problems can be framed as the data-driven discovery of unknown functions in a computational hypergraph whose structure is known (Type 2), many require the data-driven discovery of the structure (connectivity) of the hypergraph itself (Type 3). We introduce an interpretable Gaussian Process (GP) framework for such (Type 3) problems that does not require randomization of the data, access to or control over its sampling, or sparsity of the unknown functions in a known or learned basis. Its polynomial complexity, which contrasts sharply with the super-exponential complexity of causal inference methods, is enabled by the nonlinear ANOVA capabilities of GPs used as a sensing mechanism.
Random expansive measures
Authors: Bilbao Rafael A , Oliveira Marlon , Santana Eduardo
Published: August 2024

The notion of expansivity and its generalizations (measure expansive, measure positively expansive, continuum-wise expansive, countably-expansive) are well known for deterministic systems and can be a useful property for studying significant type of behavior, such as chaotic one. This study aims to extend these notions into a random context and prove a relationship between relative positive entropy and random expansive measures and apply it to show that if a random dynamical system has positive relative topological entropy then the w-stable classes have zero measure for the conditional measures. We also prove that there exists a probability measure that is both invariant and expansive. Moreover, we obtain a relation between the notions of random expansive measures and random countably-expansive systems.
Short-term power load forecasting based on ARIMA-LSTM
Authors: Zhou Ruiyan , Zhang Xingchen
Published: August 2024

Accurate short-term forecasting of power load demand has become increasingly crucial in the field of electric systems due to the continuous development of society. This paper utilizes the ARIMA and the LSTM algorithm to forecast the future 24-hour electricity load of a region. The coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), and mean absolute precision (MAPE) are utilized as model performance indexes. The prediction results for this data show indicator values of 0.843, 576.233, 435.423, and 6.964 for the ARIMA model, and 0.970, 243.86, 185.80, and 2.859 for the LSTM method. An improved ARIMA-LSTM model is then proposed, with weights assigned based on the magnitude of the errors predicted by the two models in the training set. Finally, the prediction results are obtained using the weights. The index values of the improved method are 0.9732, 241.39, 36.78, and 2.828. These indicate that the ARIMA-LSTM model outperforms the first two models.
PSO-optimized fuzzy MRAS control for permanent magnet synchronous motorized spindle
Authors: Lu Dongxi , Shan Wentao , Yun Zhiheng , Cao Weichang
Published: August 2024

With the widespread adoption of Permanent Magnet Synchronous motorized spindles in industrial applications, the demand for their precise control has escalated significantly. However, within the realm of sensorless control strategies, traditional Model Reference Adaptive Systems (MRAS) exhibit certain shortcomings, such as the complexity of parameter tuning and a heightened sensitivity to external disturbances. Addressing the deficiencies of traditional model reference adaptive systems (MRAS) in sensorless control of permanent magnet synchronous motorized spindle, this paper introduces a speed estimation strategy based on a PSO-optimized fuzzy MRAS. Fuzzy MRAS is devised using fuzzy theory on the foundation of a stator current model-based MRAS, eliminating the need for tuning the Proportional-Integral (PI) adaptive mechanism. Furthermore, the particle swarm optimization (PSO) algorithm is applied to optimize relevant parameters within the fuzzy MRAS, enhancing its dynamic performance and robustness. Simulation experiments demonstrate that the designed PSO-optimized fuzzy MRAS observer exhibits superior tracking performance across various speed ranges and in the presence of external disturbances.
Numerical simulation of local electric field distribution in epoxy/alumina nanocomposites at LN2 temperature
Authors: Wang Yongguang , Sun Bo , Guo Fen , Fu Changzhao , Ding Zhifu
Published: August 2024

Epoxy-based nanocomposites with excellent insulation characteristics are attracting extensive attention as a new insulating material for superconducting transmission. However, it is difficult to design the composite insulation layer of cables owing to limited knowledge of the local electric field distribution in nanocomposites at cryogenic temperatures. In this work, a numerical investigation of local electric field distribution in epoxy/alumina nanocomposites at room (298 K) and liquid nitrogen (LN2) temperature (77 K) was conducted under the COMSOL Multiphysics environment. Typical needle-plate electrode configuration and thermal and static electric field coupling are constructed. Based on the simulation results, it is shown that electric field distortion may occur near the needle tip due to the difference in dielectric permittivity between alumina and epoxy matrix; however, the distortion brought on by the nanoparticle and its hindering effect limit each other. The maximum electric field does not always increase with the enhancement of filler contents. Cryogenic environments can change the electric field distribution in nanocomposites but not independently in pure epoxy. In the nanocomposites, cryogenic environments do not effectively limit partial discharge by changing the electric field distribution. Its greater contribution is to limit the movement of molecular chains and work with the nanoparticles to transfer the heat generated by partial discharge.
The responsibility allocation method for overvoltage problem in distribution network with large-scale distributed photovoltaics integration based on the improved Shapley value
Authors: Li Jun , Yang Chen , Lu Zhou , Chen Jianhua , Chen Yizhi
Published: August 2024

Aiming at the node overvoltage problem due to distributed PV generation large-scale integrated into the distribution network, an improved overvoltage apportionment method is proposed to determine the overvoltage responsibility of each PV generation system. Based on the node Shapley value calculation with the voltage loss function, the influence factor of the distribution network is derived, and the improved Shapley value correction factor is obtained by using the gray correlation analysis method. The improved Shapley value is used to calculate the overvoltage responsibility. The nodes with a similar voltage change trend, in the calculation example of the PG&E-69 node distribution system, can be combined to reduce the calculation burden. The simulation results show that the improved Shapley value is more fair and reasonable than the Shapley value, considering the influence of all factors comprehensively.
Electromagnetic composite field analysis of underwater sound source based on fast Fourier transform
Authors: Gao Sibo , Wang Ying , Zhang Qiang , Sun Zhigang , Tang Pishi , Wu Di
Published: August 2024

This article demonstrates the complete transient analysis of speaker drivers, supporting the modeling of nonlinear effects. The simulation analysis includes the nonlinear characteristics of soft iron in the magnetic system, geometric nonlinearity in the structure, and the nonlinear effects caused by topological changes when the voice coil enters and exits the magnetic gap. By constructing the model, dividing the mesh, simulating the magnetic field in and around the voice coil gap, calculating the distribution of sound pressure level and the relationship between the dynamic force factor and the relative position of the voice coil, the spectrum analysis of the output signal was completed based on the fast Fourier transform.
Research on equivalent modeling of wideband dielectric response of oil-paper insulation based on the Kramers-Kronig transform
Authors: Lin Xinliang , Zou Yang
Published: August 2024

To address the limitations of the Debye model and its derived models in effectively capturing the microscopic properties of dielectric materials, this study focuses on the wideband dielectric response of oil-paper insulation and conducts equivalent modelling research. Firstly, the Kramers-Kronig (K-K) transform is applied to extract the independent spectra of the conductivity process, non-dispersive polarization process, and relaxation polarization process within a wide frequency band, clarifying the composition of the broadband dielectric response of oil-paper insulation. Then, based on the spectral analysis results, electrical units are selected to construct the equivalent model. Finally, a method combining the K-K transform with the Grey Wolf Optimization (GWO) algorithm for model parameter identification is proposed. The study demonstrates that under the influence of a wideband alternating electric field, oil-paper insulation exhibits the conductivity process, low-frequency dispersive response, relaxation-peak type response, and non-dispersive polarization process. Based on this finding, the proposed equivalent model for dielectric response effectively characterizes the complex polarization processes of oil-paper insulation, providing the necessary model foundation for the analysis of dielectric responses.
Analysis of electromagnetic denial technology and characteristics
Authors: Kong Lingmin , Zeng Sha , Chen Lei , Cao Mengdi , Liu Kang , Wang Geng
Published: August 2024

Electromagnetic denial is a new type of combat style, and the comprehensive analysis of its technology and characteristics is of great practical significance. At present, research on electromagnetic denial warfare is still in its early stages. The paper first analyzes and explains the important value of electromagnetic denial from the basic connotation. Then, based on the idea of electromagnetic denial, the key technologies of electromagnetic denial warfare are discussed from three aspects: reconnaissance, interference, and defense. Finally, the characteristics of electromagnetic denial warfare are analyzed from the aspects of technical characteristics, tactical characteristics, and system characteristics. The paper provides a reference for the technical and tactical application of electromagnetic denial.
Online software design for short-term load forecasting based on design patterns
Authors: Li Hong , Li Beicun , Chen Yanming
Published: August 2024

In response to the limitations inherent in methodologies reliant upon manual operations and practical experiences, commonly employed within the domain of load forecasting, such as convoluted operational procedures and suboptimal accuracy rates, this study introduces a novel online short-term load forecasting software solution. The developed software leverages cross-platform programming languages, notably Java and Python, alongside an object-relational mapping (ORM) framework to encapsulate database interactions, while adopting a browser/server (B/S) architecture. Furthermore, the software’s development process incorporates appropriate design patterns from object-oriented design (OOD), establishes an exception-handling architecture, and adheres to principles of test-driven development (TDD) to uphold superior software quality standards. Upon completion of construction and rigorous testing, the online short-term load forecasting software exhibits exceptional responsiveness to evolving functional requirements, thereby demonstrating its adaptability and scalability. Furthermore, its sustained operation over an extended duration underscores both its engineering feasibility and intrinsic software quality.
A comprehensive diagnostic method for UHVDC commutation failure considering the influence of AC/DC coupling
Authors: Zhuang Zengbao , Xiao Huafeng
Published: August 2024

Commutation failure is one of the most common faults in Ultra High Voltage Direct Current (UHVDC) systems. As voltage levels and transmission capacities continue to increase, the degree of coupling between AC and DC intensifies, making the commutation failure problem more complex. Identifying the source of failure is of significant practical value in enhancing the operational reliability of UHVDC systems. A comprehensive diagnosis method for UHVDC commutation failure considering the impact of AC/DC coupling is proposed in the article. Firstly, the fault types are classified based on the commutation failure ledger within the converter station. The variation in AC voltage is utilized to trace the fault layers and types of AC grid faults under interlayer coupling. The ratio of the integrated change in bipolar DC current is employed to select fault poles under intrapolar coupling. Building upon the analysis of the interaction between AC and DC coupling, a comprehensive diagnostic method for commutation failures is presented. Finally, the correctness and effectiveness of the proposed method and criterion are verified through calculation and analysis of on-site recording data, providing a practical method for locating the source of commutation failure faults.
Degradation of springs used in high-voltage breaker under the simulated operating conditions
Authors: Yang Mingkun , Qiu Pengfeng , Yang Kun , He Xiaohui , Peng Zhaoyu , Zhou Fangrong , Hu Guangfu , Zhang Yun , Luo Jie
Published: August 2024

As a key part of high-voltage breakers, spring actuators are widely used for their advantages of simple structure, rapid response, and no pollution. As the energy storage unit, the spring is prone to stress relaxation and fatigue fracture due to the complex manufacturing process, large working load, long serving time, and environmental impact. To address these issues, the degraded characteristics of the typical 60Si2CrVA alloy steel spring were studied in the simulated working conditions, and the influence of different temperature, humidity, and salt spray conditions on the performance of the spring was analyzed. The results show that temperature and salt spray corrosion are two of the main factors to affect the mechanical performance of the spring. As the temperature increases, the maximum stress loss rate of the spring increases quickly in the initial stage and then gradually keeps stable in the second stage. Under corrosive conditions, the springs are more likely to reach the stress relaxation rate threshold in a short time. For the life prediction of springs, the mathematical model was constructed by an adjusted Arrhenius equation to fit the experimental data, and calculate the numerical parameters of the spring under different environmental conditions. It is found that the service life of the spring is about 28.51 years when running at 30°C with a stress relaxation threshold of 6%.
Direct torque control of dual three-phase permanent magnet motor based on improved duty cycle calculation
Authors: Wu Yutao , Zhang Yi , Cui Jia
Published: August 2024

The multiphase permanent magnet synchronous motor (PMSM) has the following advantages: compact construction, strong fault tolerance, high power density, and small torque ripple. The motor is extensively applied to various fields, including military and electric vehicles. In this paper, a direct torque control (DTC) strategy is proposed based upon combining synthetic virtual vector and duty cycle modulation to address the drawbacks of large current harmonics and high motor losses during the traditional DTC process of dual three-phase PMSM. Building upon the conventional torque deadbeat principle, the duty cycle of the voltage vector can be worked out. Therefore, a duty cycle calculation approach is put forward on the grounds of reference torque prediction, which accurately estimates the torque demand of the motor during each sampling period, enabling the control system to more accurately calculate the appropriate duty cycle to meet real-time torque requirements. Through simulation, it is exhibited that this approach can efficiently lessen harmonic current and torque ripple while maintaining the advantages of traditional DTC.
Adaptive finite-time sliding mode control of robot manipulators with possible actuator failures
Authors: Wang Chenxi , Zeng Yong , Tang Haifeng , Zhang Yuping
Published: August 2024

In this paper, we present an adaptive finite-time fault-tolerant control scheme for a class of robot manipulators with total loss-of-effectiveness actuator failures. First, to accommodate the uncertainties caused by unknown failures, a novel decoupling method is developed to separate the uncertain fault parameters and control input in dynamics. Furthermore, by utilizing an integral fast terminal nonsingular sliding mode control strategy, the output state will reach the vested sliding surface within the fixed time. In this sense, the position errors are limited to the preset range within the set time, while avoiding singularity problems. With our scheme, all signals are guaranteed to converge to zero in the robot manipulator closed-loop dynamics. Simulation and experiment results are displayed to verify the effectiveness of the controller.
Research and simulation of high-efficiency disturbance rejection speed control strategy for PMSM
Authors: Pan Feng
Published: August 2024

Aiming at the issue of degraded control performance of the permanent magnet synchronous motor (PMSM) in the servo system of a certain type of naval gun under high sea conditions, this paper proposes an improved sliding mode control strategy with an extended state observer. By introducing a new approaching rate, the high-frequency chattering problem in traditional sliding mode control is reduced. A disturbance observer is designed to estimate and compensate for motor parameter perturbations and load disturbances through feedforward compensation, further enhancing control accuracy. Finally, a simulation model is built using Matlab/Simulink to verify the superiority of the proposed control strategy, which is of great significance for improving the performance of the naval gun servo system.
Research on thermal control during gearshift in hybrid vehicles
Authors: Liu Yiqiang , Jing Junchao , Wang Zhentao , Huang Weishan , Yu Xuemei
Published: August 2024

Aiming to address the issue of elevated clutch surface temperature in hybrid transmission vehicles during large load power upshift, a comprehensive analysis is conducted on the impact of shifting stages on temperature rise. This paper analyzes the cause of excessive heat load of the clutch in the process of high torque power upshift, and the main factors affecting the production of slip work. Various calibration strategies are introduced to mitigate overheating problems during high torque power upshifts, followed by optimized calibration, and comparative real-world vehicle testing is also conducted. The test results demonstrate that this calibration method effectively resolves the challenge of excessive thermal load on different high-torque power upshift clutches while significantly enhancing drivability.
Trajectory tracking control of four-jointed robotic fish based on Udwadia-Kalaba theory
Authors: Chen Kun , Wang Yang , Wang Huitan , Xia Yuyong , Ding Haicheng
Published: August 2024

To improve the trajectory tracking control of the robotic fish driven by four-joint tail fins, the paper has established the dynamic model of four-joint tail fins on Udwadia-Kalaba theory and designed a sliding mode controller for trajectory tracking. Meanwhile, the stability of the robotic fish has been analyzed and discussed. A comparative study of the sliding mode controller and PID controller has been conducted on numerical simulation experiments. The results show the effectiveness and accuracy of the proposed control strategy. Compared with the PID controller, the sliding mode controller can converge to the desired value relatively quickly.
Analysis of photovoltaic operation characteristics and application of photovoltaic cells in Chongqing
Authors: Yang Xuemei , Li Hanjiang , Zeng Lingjian , Deng Bowen , Ren Tingting
Published: August 2024

In recent years, solar photovoltaic power generation has received great attention as a renewable energy technology. As an emerging market for photovoltaic power generation, China has ranked first in the world in installed capacity for four consecutive years since 2013. As a municipality directly under the central government and a mega city in the southwest region, Chongqing ranks last in the cumulative installed capacity of photovoltaic power generation statistics by the National Energy Administration among all provinces and cities in China. How Chongqing should respond to this situation, what is the application situation of photovoltaic power generation systems in Chongqing, whether they are worth promoting, and how to promote them are all urgent issues that need to be studied.
Design of vibration damping system and simulation study of vibration characteristics of mine personnel carrier chassis
Authors: Du Xianfeng , Liu Dawei , Sui Xi , Ma Xiyang , Li Shuai
Published: August 2024

To improve the smoothness of the vibration during the driving process of the mine personnel carrier, a simulation design study was carried out on the structure and vibration characteristics of the whole chassis system. First of all, through the vibration isolation test of the whole vehicle idling conditions suspension system, we clarify whether the vibration isolation effect is poor and determine the chassis suspension system design scheme. Secondly, the whole vehicle vibration model is used to describe the actual vibration characteristics of the mine personnel carrier, to clarify the correlation between the body center of mass vertical acceleration and suspension stiffness and damping, road excitation, and the center of mass position and other parameters, and to effectively obtain the vibration characteristics of the compartment and the smoothness of the whole vehicle through the simulation analysis of the center of mass acceleration. Finally, based on a reasonable configuration of the system’s inherent frequency and decoupling rate, optimizing the suspension stiffness as a variable and the decoupling rate as a target can effectively improve the vibration isolation performance of the suspension system. The design and simulation of the vibration characteristics of the chassis system for the optimization of the suspension system provides a design idea for the vibration isolation system of the compartment assembly of future mining engineering vehicles.
Analysis of energy storage operation and configuration in high percentage wind power electric system
Authors: Qiu Yujia
Published: August 2024

To promote new energy sources, energy storage in high wind power systems is crucial for green, efficient, and cost-effective electrical supply. We focus on timing this setup in electrical engineering. Our analysis minimizes unit electricity supply cost in a dynamic thermal power system using a heuristic genetic algorithm. Results under different carbon capture costs show unit electricity supply costs of 0.158 CNY to 0.231 CNY. For wind turbine units, a visualization method analyzes power generation profiles, finding an abandoned wind power of 80.452MW. Replacing a 3MW thermal power unit with a 300MW wind turbine reduces integration capacity by about 80MW. Considering abandoned wind power and load shedding, calculations reveal a wind power integration capacity of around 256MW. Using dynamic programming and supplying power at the lowest generation cost, we calculate unit electricity supply cost and related indicators. This analysis, supported by data, provides insights for optimizing energy storage in high wind power systems.
Design of robot inspection system for large converter station
Authors: Yang Shaoyuan , Yang Xuefei , Li Hongkun , Song Yang , Liao Zhixu
Published: August 2024

Aiming at the development of a modern power grid and the demand for automatic maintenance, a robot safety inspection system is designed for large converter stations based on infrared temperature measurement and robot technology. The system consists of a terminal detection layer, network transmission layer, and client receiving layer. Its control software provides information processing functions including monitoring preview, video playback, user information configuration, etc. After the preset position of the inspection robot is set, the system can automatically control the robot to capture and record the image of the power equipment in the converter station at a fixed time interval set the path, and transmit it to the background software for temperature data analysis, defect location, curve display and alarm. Through the experiment and test analysis in a converter station, the results show that the system has a stable operation effect, can operate normally in four modes of manual inspection, daily inspection, detailed inspection, and server hosting, and has strong anti-interference ability, which meets the expected design requirements.
Digital twin for mobile robot modeling and simulation
Authors: Kang Ruwen , Dong Zhe , He Jiahuan
Published: August 2024

With the rapid development of mobile robotics, deploying robots in more realistic testing environments to accurately and rapidly validate control algorithms has become a major challenge in the current mainstream. Traditional robot simulation systems are mostly built on a two-dimensional plane, with poor visualization performance and an inability to reflect real testing environments. This poses a significant portion of the research and development costs when validating robot algorithm functionalities. To address the aforementioned issues, this paper proposes a solution based on 3D reconstruction technology to create a twin scene that accurately represents the real simulation environment. Unity3D engine is utilized to develop a 2D LiDAR distance measurement sensor, and a complete control process for mobile robots is built in Matlab/Simulink. This enables hardware-in-the-loop simulation testing. Through experimental validation, it has been demonstrated that prior to conducting full-scale physical simulations, robots can effectively simulate the control logic within the virtual environment. This allows for online adjustments of various parameters in the control algorithms, leading to improved research and development efficiency while reducing potential risks and costs associated with deploying robots in real-world environments.