bluuebunny/crossref_metadata_2025 huggingface dataset:
Chaotic dynamics of flexible graphene electronic membranes with variable density in motion
Authors: Ying Shudi , Wu Jimei , Cai Zhiduan , Wang Yuling
Published: October 2024

With advancements in artificial intelligence and wearable technology, flexible electronic devices characterized by their flexibility and extensibility have found widespread applications in fields such as information technology, healthcare, and military. Printing technology can accurately print a circuit diagram onto a flexible membrane substrate by the pressure transfer of a conductive ink, which makes the large-scale printing of flexible graphene electronic membranes possible. However, during the roll-to-roll printing process used to prepare flexible graphene electron membranes, the density of electron membranes is variable due to the uneven distribution of inkjet-printed circuits, which limits the printing speed of flexible graphene electron membranes. Hence, investigating the dynamic properties of flexible graphene electron materials with different densities is of paramount importance to improve the production efficiency and quality of flexible graphene electron membranes. This paper takes roll-to-roll intelligent graphene electronic membranes as the research object. According to Hamilton’s principle, nonlinear vibration partial differential equations for the motion of flexible graphene electron membranes with varying densities were established and subsequently discretized using the assumed displacement function and the Bubnov–Galerkin method. Through numerical calculations, the simulation results obtained based on the fourth-order Runge–Kutta method and the multiscale algorithm were compared, and the multiscale algorithm was verified to be more correct and effective. The primary resonance amplitude–parameter characteristic curve, along with phase-plane portraits, Poincaré maps, power spectrum, time history plots, and bifurcation diagrams, for the nonlinear behavior of the membrane was obtained. The impacts of the density coefficient, velocity, damping ratio, excitation force, and detuning parameters on the nonlinear primary resonance and chaotic behavior of the moving graphene electron membrane were determined, and the stable operational region was identified, laying a theoretical foundation for the development of flexible graphene electronic membranes.
Ultra-fine nano-crystalline optimize electrostatic energy storage
Authors: Zhang Y. , Song D. P. , Han Y. X. , Lei Y. , Li R. Z. , Yang J.
Published: October 2024

Grain size pays a crucial role in the properties of ferroelectrics and dielectrics. Reducing the grain size is considered to be an effective mean for enhancing dielectric energy storage. In this work, high recovered energy storage density and efficiency were achieved in three-layered Aurivillius thin films by ultra-fine grain nano-crystalline engineering. The ultra-low remanent polarization can be attributed to the emergence of polar nano-regions due to the disruption of macroscopic continuity of ferroelectric domains by ultra-fine nano-grains. At the same time, all thin films have high dielectric breakdown strength due to the presence of extremely high grain boundary density. Thus, a high recovered energy storage density of 71 J/cm3 and an efficiency of 76% were achieved, and the thin film capacitors show good fatigue endurance and temperature stability. The results suggest that ultra-fine nano-crystalline engineering can expand the application of traditional ferroelectric thin films in energy storage devices.
Numerical simulation analysis of turbulent pulsation drag reduction at different intermittent times
Authors: Wang Kun Ying , Sun Bo Hua
Published: October 2024

The shear stress generated by wall turbulence is the main cause of wall friction resistance in turbulent flow through pipes. This paper investigates the impact of inserting rest periods (regions of constant Reynolds number) within the pulsating operating cycle of velocity on the fully turbulent flow at large time-averaged Reynolds numbers, using the large eddy simulation (LES) method. The study aims to explore the effect of increasing rest periods within pulsations on drag resistance. The dimensionless shear stress and drag reduction rates during different time periods of rest were analyzed. Numerical simulation results indicate that the pulsating velocity operation mode does not necessarily lead to drag reduction; it may even result in increased resistance. Inserting rest periods within the pulsation cycle can achieve drag reduction effects, with the maximum drag reduction rate reaching 21.8%. This paper utilizes large eddy simulation (LES) to compare and validate the feasibility of LES for pipe pulsating operation modes against experimental results and direct numerical simulation (DNS) results from the literature, providing a rationale and proof of concept for further in-depth studies on other pipe pulsating flows.
Study on single particle compression crushing characteristics of iron ore with five different particle sizes
Authors: Yin Zixin , Wang Nan , Li Tongqing
Published: October 2024

The mechanical properties of particulate materials are among the main factors affecting the grinding and crushing of ball mills. To quantitatively describe the relationship between the breakage characteristics and the stress intensity of irregular particulate materials, this study takes iron ore particles as the research object. It selects five particle size grades of iron ore particles (−4.75 + 3.35, −6.7 + 4.75, −9.5 + 6.7, −13 + 9.5, and −16 + 13 mm) for single particle strength tests. The results showed that the iron ore particles were irregular with certain slenderness and flatness characteristics. The larger the particle size, the lower the sphericity, and the greater the degree of irregularity. As the size of the iron ore particles increased, the number of peak points on the pressure–displacement curve of the particles increased significantly, and the crushing load increased. The single-particle strength of the iron ore particles followed a Weibull distribution, and the Weibull modulus parameter ranged between 2.03 and 2.49.
Effects of discharge parameters on plasma acceleration and transmission characteristics of a coaxial gun operated in gas-prefilled mode
Authors: Liu Shuai , Qi Liangwen , Zhang Guipeng , Xiao Dingbang , Yu Siqi
Published: October 2024

The effects of discharge parameters on the discharge process and plasma transport characteristics of a coaxial gun in the gas-prefilled mode are studied. The plasma optical intensity and ejection velocity are measured by photodiodes, the optical emission spectrum is taken by a spectroscopic system, and the plasma evolution in the transport process is captured by a high-speed camera. The plasma acceleration characteristics under different discharge parameters show that the velocity and electron density of the ejection plasma are mainly determined by the pre-filled pressure and discharge current, which is consistent with the snowplow model. The kinetic energy of ejection plasma can be significantly increased by reducing the outer loop inductance, which is conducive to increasing the energy utilization efficiency. The time-varying images of plasma radiation and the plasma density at different transport locations illuminate the transmission characteristics of coaxial gun discharge plasma. The results show that the snowplow effect continues to play a role in the plasma transport process, and the plasma accumulation is induced by the combination of shock wave compression. The current-driven magneto hydrodynamics instability occurs during the transport process, and the luminous signal of the plasma current sheet oscillates periodically. In addition, the plasma impact effect is obvious and the gas retarding effect is enhanced with the increase in the gas pressure. These results give us a more comprehensive view of the coaxial gun discharge process and plasma transport and provide a certain reference for optimizing the parameters selection and physical design of coaxial gun discharge plasma characteristics.
Exploring the molecular pathways of the activation process in PPARγ recurrent bladder cancer mutants
Authors: de Oliveira Vinícius M. , Malospirito Caique C. , da Silva Fernando B. , Videira Natália B. , Dias Marieli M. G. , Sanches Murilo N. , Leite Vitor B. P. , Figueira Ana Carolina M.
Published: October 2024

The intricate involvement of Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) in glucose homeostasis and adipogenesis is well-established. However, its role in cancer, particularly luminal bladder cancer, remains debated. The overexpression and activation of PPARγ are implicated in tumorigenesis. Specific gain-of-function mutations (M280I, I290M, and T475M) within the ligand-binding domain of PPARγ are associated with bladder cancer and receptor activation. The underlying molecular pathways prompted by these mutations remain unclear. We employed a dual-basin structure-based model (db-SBM) to explore the conformational dynamics between the inactive and active states of PPARγ and examined the effects of the M280I, I290M, and T475M mutations. Our findings, consistent with the existing literature, reveal heightened ligand-independent transcriptional activity in the I290M and T475M mutants. Both mutants showed enhanced stabilization of the active state compared to the wild-type receptor, with the I290M mutation promoting a specific transition route, making it a prime candidate for further study. Electrostatic analysis identified residues K303 and E488 as pivotal in the I290M activation cascade. Biophysical assays confirmed that disrupting the K303–E488 interaction reduced the thermal stabilization characteristic of the I290M mutation. Our study demonstrates the predictive capabilities of combining simulation and cheminformatics methods, validated by biochemical experiments, to gain insights into molecular activation mechanisms and identify target residues for protein modulation.
Hierarchical equations of motion for multiple baths (HEOM-MB) and their application to Carnot cycle
Authors: Koyanagi Shoki , Tanimura Yoshitaka
Published: October 2024

We have developed a computer code for the thermodynamic hierarchical equations of motion derived from a spin subsystem coupled to multiple Drude baths at different temperatures, which are connected to or disconnected from the subsystem as a function of time. The code can simulate the reduced dynamics of the subsystem under isothermal, isentropic, thermostatic, and entropic conditions. The extensive and intensive thermodynamic variables are calculated as physical observables, and Gibbs and Helmholtz energies are evaluated as intensive and extensive work. The energy contribution of the system–bath interaction is evaluated separately from the subsystem using the hierarchical elements of the hierarchical equations of motion. The accuracy of the calculated results for the equilibrium distribution and the two-body correlation functions is assessed by contrasting the results with those obtained from the time-convolution-less Redfield equation. It is shown that the Lindblad master equation is inappropriate for the thermodynamic description of a spin–boson system. Non-Markovian effects in thermostatic processes are investigated by sequentially turning on and off the baths at different temperatures with different switching times and system–bath coupling. In addition, the Carnot cycle is simulated under quasi-static conditions. To analyze the work performed for the subsystem in the cycle, thermodynamic work diagrams are plotted as functions of intensive and extensive variables. The C++ source codes are provided as supplementary material.
Universal programmable unambiguous discrimination of two unknown states with two copies
Authors: Wang Shou-Ya , Zhang Wen-Hai
Published: October 2024

We investigate the universal programmable unambiguous discrimination of two unknown quantum states with two copies. We first present the optimal positive-operator valued measure (POVM) elements that determine the individual success probabilities. In terms of the positivity of an inconclusive operator, we derive the average success probability, which is higher than the average success probability of discriminating two unknown states with one copy given in the reference [Bergou and Hillery, Phys. Rev. Lett. 94, 160501 (2005)].
Li-ion solvation structure at electrified solid–liquid interface: Understanding solvation structure dynamics and its role in electrochemical energy storage through binary ethylene carbonate and dimethyl carbonate solvent
Authors: Hamza Muhammad , Mei Bing-Ang , Liao Ridong , Feng Huihua , Zuo Zhengxing , Xiong Rui
Published: October 2024

Binary solvent electrolytes can provide interpretations for designing advanced electrolytes of next generation batteries. This study investigates the adsorption mechanisms of solvated lithium ions in binary solvents near charged electrodes. Molecular dynamic simulations are performed for lithium hexafluorophosphate (LiPF6) in ethylene carbonate and dimethyl carbonate (EC:DMC) solvent sandwiched between two electrodes. Results show that lithium ions form a tetrahedral solvation structure with two EC and two DMC molecules. The solvated lithium ion shows anti-electrostatic interaction with electrodes. This can be attributed to the electrostatic attraction of the polar end of the DMC molecule, which keeps the cation anchored to the positive electrode. Meanwhile, the solvation structure adopts a fix orientation at the negative electrode, which leads to unchanged electrostatic interaction at high charge density. Finally, EC molecules are swapped by DMC molecules near the negative electrode at high charge density. This leads to a decrease in local relative permittivity and, therefore, a decrease in differential capacitance. The differential capacitance of the positive electrode continuously decreases with increasing charge density. This is caused by the partial anchoring of solvent molecules holding the cations, which cancels the adsorption of anions near the positive electrode. This study provides insights into designing better electrolytes for efficient battery performance.
Stochastic optimal allocation of grid-side independent energy storage considering energy storage participating in multi-market trading operation
Authors: Xu Jiayin , Wang Xuli , Zhu Liuzhu , Shen Yuming , Guo Wenzhang , Hu Xudong , Ma Yinghao , Huang Rishun
Published: October 2024

The integration of large-scale intermittent renewable energy generation into the power grid imposes challenges to the secure and economic operation of the system, and energy storage (ES) can effectively mitigate this problem as a flexible resource. However, the conventional ES allocation is mostly planned to meet the regulation demands of individual entities, which is likely to result in low utilization of ES and difficult to recover the investment cost. Therefore, a two-stage stochastic optimal allocation model for grid-side independent ES (IES) considering ES participating in the operation of multi-market trading, such as peak-valley arbitrage, frequency regulation, and leasing, is proposed in this paper to improve the comprehensive benefits and utilization rate of ES. The first stage aims to allocate IES and develop a systematic scheduling plan based on the forecast of wind power output and load demand, while the second stage responds to the uncertainty of wind power output by re-dispatching generating units and invoking ES power leased by wind farms. Then, a two-layer loop iterative solution algorithm based on the Benders decomposition is formed to effectively solve the proposed model. Finally, the approach developed in this paper is applied to a modified IEEE RTS-79 test system, and the results verify that it is both feasible and effective.
A semi-analytical prediction model for fluid elastic instability in the streamwise direction of a normal triangular tube array
Authors: Jiang Naibin , Chen Gongbo , Shen Sisi
Published: October 2024

Fluid elastic instability (FEI) is widely regarded as the most destructive mechanism of flow-induced vibration. Numerous failures of heat exchanger tubes have been attributed to this phenomenon. This paper focuses on a normal triangular tube array and develops a semi-analytical time-domain solving model to address FEI in the streamwise direction. Utilizing computational fluid dynamics simulations and image processing techniques, a comprehensive set of tube-in-channel model parameters is derived, including the area perturbation amplitude, phase difference, mean area along the flow channel, and steady-state term of flow velocity. Tube motion in the streamwise direction generates a disturbance distinct from that caused by transverse flow, leading to revisions in the expressions of relevant model parameters. Furthermore, variations in these parameters across different positions and velocities are quantitatively analyzed through function fitting, yielding specific mathematical formulas. Ultimately, the derived tube-in-channel model parameters applicable to streamwise FEI are validated against experimental data, affirming the model's accuracy.
Room temperature mid-wave infrared guided mode resonance InAsSb photodetectors
Authors: Mansfield N. C. , Tischenko Y. , Bergthold M. , Purkait S. , Raju A. , Kamboj A. , Podolskiy V. A. , Wasserman D.
Published: October 2024

We demonstrate room temperature operation of mid-wave infrared photodetectors leveraging a guided mode resonance architecture and bulk alloy InAsSb absorbers. Room temperature operation with low dark current is achieved by using detector structures with ultra-thin (150, 250 nm) absorbers leveraging the strong confinement enabled by the guided mode architecture. Devices with 1D and 2D grating arrays are fabricated and characterized, and compared to unpatterned detector devices. We see enhancement in the detectors’ optical response associated with coupling to both TE- and TM-polarized guided modes and good agreement between experimental and theoretically-predicted behavior. We show strong enhancement for unpolarized light incident on 2D grating arrays, with a broader spectral response than observed for polarized light incident upon 1D grating GMR detectors. The bulk InAsSb detectors presented in this work offer enhanced performance at room temperature for a range of imaging and sensing applications.
Experimental and numerical fire behaviour analysis in Eucalyptus globulus trees
Authors: Modarres MohammadReza , Almeida Miguel , Viegas Domingos X.
Published: October 2024

Background Eucalyptus globulus is highly susceptible to fire, and contributes to increased fire intensity. In 2021, it spanned 25 million hectares, marking it as the forest genus with the broadest area of cultivation. Aims This study investigates the flammability characteristics of Eucalyptus globulus relative to the fuel age, focusing on fire thermal and physical characteristics. Methods Experimental and numerical analyses were performed using the Fire Dynamics Simulator (FDS) within the large-eddy simulation (LES)-based Lagrangian particle cloud model. Results Six-month-old Eucalyptus globulus trees present a significant fire hazard. Older trees (3 and 5 years) exhibit more intense burns owing to reduced moisture content and larger fuel elements. Conclusions The flammability of Eucalyptus globulus varies with the growth stage, as older plants generate higher heat flux and burn more intensely owing to larger fuel elements, concentrated volatile compounds and reduced moisture content. In contrast, younger plants are more prone to ignition but exhibit lower heat flux and higher flame lengths relative to crown height. Simulations using FDS 6.8.0 effectively can predict plants’ key flammability and fire characteristics based on detailed laboratory data, demonstrating this tool’s capability in fire dynamics modelling and its behaviour prediction. Implications These findings can enhance fire modelling result quality and risk assessment in eucalyptus forests, guiding targeted fire management strategies.
Cryo-EM structure of the zinc-activated channel (ZAC) in the Cys-loop receptor superfamily
Authors: Jin Fei , Lin Yi-Yu , Wang Ru-Chun , Xie Tang-Xuan , Zhao Yimeng , Shen Cheng , Sheng Danqi , Ichikawa Muneyoshi , Yu Ye , Wang Jin , Hattori Motoyuki
Published: October 2024

Cys-loop receptors are a large superfamily of pentameric ligand-gated ion channels with various physiological roles, especially in neurotransmission in the central nervous system. Among them, zinc-activated channel (ZAC) is a Zn
2+
-activated ion channel that is widely expressed in the human body and is conserved among eukaryotes. Due to its gating by extracellular Zn
2+
, ZAC has been considered a Zn
2+
sensor, but it has undergone minimal structural and functional characterization since its molecular cloning. Among the families in the Cys-loop receptor superfamily, only the structure of ZAC has yet to be determined. Here, we determined the cryo-EM structure of ZAC in the apo state and performed structure-based mutation analyses. We identified a few residues in the extracellular domain whose mutations had a mild impact on Zn
2+
sensitivity. The constriction site in the ion-conducting pore differs from the one in other Cys-loop receptor structures, and further mutational analysis identified a key residue that is important for ion selectivity. In summary, our work provides a structural framework for understanding the ion-conducting mechanism of ZAC.
Curvature fluctuations of fluid vesicles reveal hydrodynamic dissipation within the bilayer
Authors: Faizi Hammad A. , Granek Rony , Vlahovska Petia M.
Published: October 2024

The biological function of membranes is closely related to their softness, which is often studied through the membranes’ thermally driven fluctuations. Typically, the analysis assumes that the relaxation rate of a pure bending deformation is determined by the competition between membrane bending rigidity and viscous dissipation in the surrounding medium. Here, we reexamine this assumption and demonstrate that viscous flows within the membrane dominate the dynamics of bending fluctuations of nonplanar membranes with a radius of curvature smaller than the Saffman–Delbrück length. Using flickering spectroscopy of giant vesicles made of dipalmitoylphosphatidylcholine, DPPC:cholesterol mixtures and pure diblock-copolymer membranes, we experimentally detect the signature of membrane dissipation in curvature fluctuations. We show that membrane viscosity can be reliably obtained from the short time behavior of the shape time correlations. The results indicate that the DPPC:cholesterol membranes behave as a Newtonian fluid, while the polymer membranes exhibit more complex rheology. Our study provides physical insights into the time scales of curvature remodeling of biological and synthetic membranes.
Dynamics of transcription-coupled repair of cyclobutane pyrimidine dimers and (6-4) photoproducts inEscherichia coli
Authors: Adebali Ogϋn , Sancar Aziz , Selby Christopher P.
Published: October 2024

DNA repair processes modulate genotoxicity, mutagenesis, and adaption. Nucleotide excision repair removes bulky DNA damage, and inEscherichia coli, basal excision repair, carried out by UvrA, B, C, and D, with DNA PolI and DNA ligase, occurs genome-wide. In transcription-coupled repair (TCR), the Mfd protein targets template strand (TS) lesions that block RNA polymerase for accelerated repair by the basal repair enzymes. Accelerated repair is also seen with particular adducts. Notably, of the two major UV photoproducts, basal repair of (6-4) photoproducts [(6-4)PPs] is about 10× faster than repair of cyclobutane pyrimidine dimers (CPDs). To better understand repair prioritization inE. coli, we used XR-seq to measure TCR of UV photoproducts genome-wide. With CPDs, we found that TCR occurred at early time points, increased with transcription level, and was Mfd dependent; later, with completion of TS repair, nontranscribed strand (NTS) repair predominated. With (6-4)PP, when analyzing all genes, TCR was not observed; in fact, among the most highly transcribed genes, slightly more repair of (6-4)PPs in the NTS was evident. Thus, the very rapid basal repair of (6-4)PP in the NTS was faster than TCR of (6-4)PPs in the TS. Overall, TCR is of limited importance in (6-4)PP repair, and TCR of CPDs is limited to the TS of more highly transcribed genes. These results are consistent with the significant role of Mfd in mutagenesis and the modest effect ofmfddeletion on UV survival and bear upon the response ofE. colito bulky DNA damage.
On learning the optimal regularization parameter in inverse problems
Authors: Chirinos-Rodríguez Jonathan , De Vito Ernesto , Molinari Cesare , Rosasco Lorenzo , Villa Silvia
Published: October 2024

Selecting the best regularization parameter in inverse problems is a classical and yet challenging problem. Recently, data-driven approaches based on supervised learning have become popular to tackle this challenge. These approaches are appealing since they do require less a priori knowledge, but their theoretical analysis is limited. In this paper, we propose and study a statistical machine learning approach, based on empirical risk minimization. Our main contribution is a theoretical analysis, showing that, provided with enough data, this approach can reach sharp rates while being essentially adaptive to the noise and smoothness of the problem. Numerical simulations corroborate and illustrate the theoretical findings. Our results are a step towards grounding theoretically data-driven approaches based on supervised learning to inverse problems.
Quantitative evaluation of residual resist in electron beam lithography based on scanning electron microscopy imaging and thresholding segmentation algorithm
Authors: Mao Qingyuan , Zhu Jingyuan , Wang Zhanshan
Published: October 2024

Electron beam lithography is a critical technology for achieving high-precision nanoscale patterning. The presence of resist residues in the structures can significantly affect subsequent processes such as etching and lift-off. However, the evaluation and optimization of resist residues currently relies on qualitative observations like scanning electron microscopy (SEM), necessitating multiple experiments to iteratively optimize exposure parameters, which is not only labor-intensive but also costly. Here, we propose a quantitative method to evaluate resist residues. By processing the obtained SEM images using a threshold segmentation algorithm, we segmented the resist structure region and the residual resist region in the images. The grayscale values of these two regions are identified, and the residues are quantified based on the ratio of these values. Furthermore, a relationship curve between the residue amount and the exposure dose is plotted to predict the optimal exposure dose. To validate this method, we fabricated hydrogen silsesquioxane annular grating structures with 30 nm linewidth and analyzed the residue levels over an exposure dose range of 2000–2500 μC cm–2, predicting the optimal dose to be 1800 μC cm–2 and confirming this through experiments. Additionally, we applied the method to polymethyl methacrylate and ZEP-520A structures, achieving similarly accurate results, further confirming the method’s general applicability. This method has the potential to reduce experimental costs and improve yield and production efficiency in nano fabrication.
Discharge characteristics of silicon-based DC Helium microplasmas: comparison between Through Silicon Via and closed cavity type micro-reactors
Authors: Kouadou E , Iseni S , Stolz A , Lefaucheux P , Dussart R
Published: October 2024

This paper explores the microfabrication process of plasma reactors, from the production of micro-reactors to the addition of through silicon vias (TSV) using proprietary etching techniques and on site cleanroom facilities. The investigation focuses on both newly fabricated closed and open-cavity micro-hollow cathode discharge (MHCD) reactors, with particular emphasis on electrical and optical diagnostics to characterize their plasma properties. All experiments, including those on closed-cavity reactors, were specifically conducted for this study under identical conditions to ensure a rigorous comparison between reactor types. When electrical diagnostics were carried out in helium at various pressures, interesting phenomena such as the evolution of voltage breakdown were observed. These diagnostics also provided new insights into the impact of surface electrode and overall geometry properties and pressure on reactor performance. Additional investigation into instability mechanisms revealed self-pulsing oscillations, with different reactor types having different oscillation amplitudes for similar operating conditions. Optical emission spectroscopy (OES) emerged as a strong tool for spatial plasma analysis, revealing consistent gas temperature distributions across reactor diameters. The Inglis-Teller series provided an estimate of the upper limit of electron density, while the Stark broadening analysis of

H
α

offered valuable insights into electron density variations, particularly in the self-pulsing regime.
A flexural-beam-type wide-frequency piezoelectric energy harvester for vertical shaft lifting system vibration monitoring
Authors: Ma Tianbing , Zhang Wenjie , Du Fei , Shi Rui , Zhang Zhihao
Published: October 2024

The coal mine lifting system may experience serious safety accidents due to severe problems with the bucket guides and rolling guide shoes. A piezoelectric energy harvesting (PEH) device for vibration sensor monitoring of shaft lifting system is proposed for the first time to monitor health of shaft lifting system. However, there are differences in the vibration frequencies, the working conditions are complex, leading to issues such as low energy recovery efficiency of the PEH and difficulty in achieving self-powered. To enhance PEH adaptability and reliability, a specifically designed flexural-beam-type wide-frequency piezoelectric energy harvester (FBT-WF-PEH) and a method of achieving real-time vibration monitoring through auxiliary power supply have been proposed. The results indicate when the excited frequency is 17 Hz, the highest external output voltage is 11.2 V, and under an external load of 17.5 kΩ, the maximum output power is 7.168 mW, demonstrating a good performance in terms of output power, and energy harvest bandwidth. The captive power supply test verified the PEH can utilize the vibration environment to achieve auxiliary power supply for monitoring systems under working conditions, which is of great significance for conducting research on health monitoring systems for lifting equipment. On the other hand, the new structure proposed in this study matches the operating frequency in the shaft lifting system, and the energy harvest efficiency is higher.
Highly sensitive quad-ray shaped polarization insensitive THz meta-biosensor
Authors: Ali Muhammad , Naveed Muhammad Ashar , Ramzan Faizan , Alvi Talha Shahid , Aljaloud Khaled A , Alqahtani Ali H , Alresheedi Mohammed Thamer , Hussain Rifaqat , Mehmood Muhammad Qasim
Published: October 2024

Metasurface-based sensors are now becoming crucial for label-free and rapid-detection technologies in biomedical applications, leading to a growing demand for new highly sensitive meta-biosensors. This paper demonstrates a perfectly symmetrical quad-ray X-shaped THz meta-absorber (QRXMA), enabling narrowband and polarization insensitivity performance. The theoretical modelling and performance investigation focuses on its potential for improved refractive index (RI) sensing for multiple biological samples. The simulation outcomes reveal that the proposed optimal QRXMA achieves an absorption rate of 99.98% at 1.3 THz for both TE and TM polarized incidences. Furthermore, we highlight the adjustability of absorptive characteristics of the proposed device by altering the different geometric parameters. These findings underscore the QRXMA potential in RI sensing applications, achieving a sensitivity of approximately 116.8 GHz RIU−1 and a figure of Merit (FoM) of about 2 with an 8 μm thick non-destructive analyte layer. This research makes a significant contribution to the development of highly efficient meta-biosensors with promising applications in THz detection, sensing, and imaging.
Cosmological forecasts from the combination of Stage-IV photometric galaxy surveys and the magnification from forthcoming GW observatories
Authors: Beltrame Matteo , Bonici Marco , Carbone Carmelita
Published: October 2024

In this work we have investigated the synergy between Stage-IV galaxy surveys and future GW observatories for constraining the underlying cosmological model of the Universe, focussing on photometric galaxy clustering, cosmic shear and GW magnification as cosmological probes. We have implemented a Fisher matrix approach for the evaluation of the full 6×2pt statistics composed by the angular power spectra of the single probes together with their combination. For our analysis, we have in particular considered dynamical dark energy and massive neutrino scenarios. We have found that the improvement to galaxy survey performance is below 1%, in the case of ℓ
GW
max=100 and a luminosity distance error of σ

dL
/dL
=10%. However, when extending the analysis to ℓ
GW
max=1000, we find that the GW magnification improves the galaxy survey performance on all the cosmological parameters, reducing their errors by 3%-5%, when σ

dL
/dL
=10%, and by 10%-18% when σ

dL
/dL
=1%, especially for Mν
, w
0 and wa
. However, here our analysis is unavoidably optimistic: a much more detailed and realistic approach will be needed, especially by including systematic effects. But we can conclude that, in the case of future gravitational wave observatories, the inclusion of the gravitational wave magnification can improve Stage-IV galaxy surveys performance on constraining the underlying cosmological model of the Universe.
Cosmic inflation and (g-2)
μ
in minimal gauged Lμ-Lτ
model
Authors: Paul Arnab , Roy Sourov , Saha Abhijit Kumar
Published: October 2024

The minimal U(1)
Lμ
-
Lτ
gauge symmetry extended Standard Model (SM) is a well motivated framework that resolves the discrepancy between the theoretical prediction and experimental observation of muon anomalous magnetic moment. We envisage the possibility of identifying the beyond Standard Model Higgs of U(1)
Lμ
-
Lτ
sector, non-minimally coupled to gravity, as the inflaton in the early universe, while being consistent with the (g-2)μ data. Although the structure seems to be trivial, we observe that taking into consideration of a complete cosmological history starting from inflation through the reheating phase to late-time epoch along with existing constraints on U(1)
Lμ
-
Lτ
gauge symmetry extended Standard Model (SM) is a well motivated framework that resolves the discrepancy between the theoretical prediction and experimental observation of muon anomalous magnetic moment. We envisage the possibility of identifying the beyond Standard Model Higgs of U(1)
Lμ

Lτ
model parameters leave us a small window of allowed reheating temperature. This further results into restriction of (n
s
-r) plane which is far severe than the one in a generic non-minimal quartic inflationary set up.
Self-frequency-doubling Yb:GdCOB laser intracavity-pumped Pr:YAP laser
Authors: Chu Chu , Anh Nguyentuan , Zhang Anfeng , Xia Jing
Published: October 2024

We present for the first time a Pr:YAlO3 (Pr:YAP) laser emitting at 547 nm intracavity-pumped by a self-frequency-doubling Yb3+:Ca4GdO (BO3)3 (Yb:GdCOB) blue laser at 488 nm. We carried out a model to design the system properly, and the laser performance was experimentally investigated. Intracavity sum-frequency mixing at 547 and 488 nm was then realized in a CsLiB6O10 (CLBO) nonlinear crystal to reach the ultraviolet laser at 258 nm. We obtained a continuous wave output power of 575 mW at 258 nm with a pump source, which is a diode-pumped quasi-three-level Sr1-x
La
x

-y
Nd
y
Mg
x
Al12-x
O19 (Nd:ASL) laser emitting 11.2 W at 902 nm.
Enhancing Situational Awareness for Remote Control of Ship Cranes
Authors: Bellingmo P R , Jørgensen U , Bjerkeng M , Johanson K
Published: October 2024

Cargo handling in ship operations poses risks due to heavy loads, necessitating innovation to mitigate accidents. Automation and remote control offers safer and more efficient operations by moving people from hazardous situations. Smaller and remote ports often rely on geared ships, which are typically manually operated. A first step towards automation is to remotely control these cranes. In remote control, the operator needs to gain situational awareness through sensor inputs. Previous research has shown that there is a need to investigate the sensor configuration and placement to provide situational awareness, particularly considering the placement of cargo onboard. This study seeks to identify needed sensor configurations for situational awareness in remote control of ship cranes using a simulator framework. A modular crane simulator framework has been developed to evaluate situational awareness for different sensor configurations. The sensor configuration has been evaluated with feedback from a crane expert. This research has identified potential sensor configurations for enhancing situational awareness in remote crane operations. The developed simulator framework has demonstrated its flexibility and efficiency as a platform for testing and optimizing cargo handling operations.
Harmonizing Maritime Innovation: Enhancing International and National Standardization in Intelligent Ship Transport Systems
Authors: Yeon Koo Kwi , Jan Rødseth Ørnulf , Lislebø Geir , Herman Ulvensøen Jon
Published: October 2024

The rapid advancement of maritime technologies, particularly in the domain of autonomous ships and maritime intelligent transport systems (MITS), necessitates a robust framework for digital interoperability at both national and international levels. This paper presents an in-depth analysis of the current state of standardization within MITS. It emphasizes the importance of harmonizing efforts to facilitate the integration of innovative technologies into the maritime sector, ensuring safety, efficiency, and environmental sustainability. To gain broader insights, standardization practices from other industries are examined. In conclusion, the paper argues that enhancing collaboration and standardization in MITS is essential for the successful implementation of maritime innovations. It calls for a collective effort from national and international stakeholders to develop a unified framework that supports the growth of autonomous ship technology and the evolution of intelligent maritime transport systems.
A Formalism for Scalable Maritime Traffic Monitoring and Explainable Anomaly Detection and Resolution at Vessel Traffic Services
Authors: Stach T , Koch P , Constapel M
Published: October 2024

Vessel traffic service (VTS) centres around the globe monitor and manage the ship traffic in their areas of responsibility and respond to arising unsafe or inefficient situations. Decision support tools (DST) help vessel traffic service operators (VTSO) to enhance their situational awareness and decision-making process, thus to recognise and assess dangerous situations. However, current DST have unsophisticated features and require manual configuration by the operator. Firstly, triggers for alerts are mostly based on the creation of geographical polygons for spatial-dependent assignment of rules, thresholds, ranges and limits for specific features. Secondly, calculations for the detection of safety-critical situations rely on measurements based on the closest point of approach (CPA) without taking contextual information into account. Thirdly, trajectory predictions are performed considering a constant velocity model (CVM) which does not depict reality. Due to these and other peculiarities, current DST are prone to false alerts. This results into a high workload where unsafe situations may be overlooked. In this paper, we propose a hierarchical formalism as foundation for an anomaly detection and resolution which generates less false alerts. The formalism consists of three hierarchical layers which represent, objects, measurements and situations. The formalism ensures adaptability and extensibility to various VTS areas and traffic patterns. Moreover, due to the given structure, the presented formalism is easily implementable, adaptable and scalable taking the currently available technological capabilities at VTS centres into account. We demonstrate the feasibility of this formalism by implementing a proof-of-concept and assessing it with realistic scenarios. Our implementation utilizes a rule-based system as central framework and it is configured through statistical methods, e.g. machine learning. Given this hybrid approach, the implementation provides reasonable and explainable results. This enables comprehensibility and verifiability by authorities and operators which is crucial for acceptance.
Digital twins for resource optimization in multi-purpose ports: A design approach for data-driven decision making
Authors: Karlsson M , Liu M , Li H , Haraldson S , Lind M , Mishra M , Sandberg J , Lind K
Published: October 2024

Multi-purpose ports’ ef/icient and sustainable operation relies on seamless coordination and decision-making among multiple organizations. This paper underscores the critical importance of forecasting resource and infrastructure utilization for informed operational, tactical, and strategic decision-making. The proposed approach draws on digital twin technology to enable collaborative decision-making by modeling complex port environments to enable shared situational awareness among stakeholders. Illustrated through a collaborative project involving the RISE Research Institutes of Sweden, National University of Singapore, Grieg Connect, Umeå University, Kvarken Ports Umeå, and INAB, we propose a digital twin design to empower the port as a decision-maker in multi-organizational settings to proactively plan and optimize its utilization of present and future resources.
A Modified Three-terms CG Method with the MWWP Line Search and its Application to Image Restoration
Authors: Liang Chunzhao , Yuan Gonglin , Lu Junwei
Published: October 2024

In this article, an innovative method, which integrates the optimized three-term Polak–Ribière–Polyak (PRP) conjugate gradient (CG) method with the improved WWP line search rule, is presented and applied in the field of image restoration. The proposed search direction exhibits sufficient descent and trust region characteristics, maintaining its effectiveness regardless of the specific line search rule employed. We established the global convergence of the presented algorithm and eliminated the dependence on the Lipschitz continuity assumption. The numerical comparisons with the PRP CG method revealed the superior performance of the designed algorithm in the field of image restoration. This research outcome provides strong support for further advancements in the field of image recovery.
ICOPP: A Highway Autonomous Driving Planner Based on Interactive Collaborative Optimization and POMDP
Authors: Zhao Kun , Yin Jialun
Published: October 2024

In this paper, we propose a planner for autonomous vehicles in complex highway scenarios, which can efficiently plan the trajectory of autonomous vehicles. The method aims to improve the intelligence of autonomous driving under the uncertainty of the perception and prediction system. The method employs a POMDP framework to address the challenges brought about by uncertainty. Firstly, this method divides the entire planning cycle into several discrete decision-making processes. In each process, the vehicle’s lateral and longitudinal behaviors are semantically processed to obtain a limited number of decision sequences, thereby addressing the curse of dimensionality in state space and observation space in POMDP problems. In each decision-making process, different simulation scenarios are constructed based on the decision of the self-vehicle and probability distribution of the predicting behaviors of surrounding vehicles. In each scenario, key vehicles are selected for collaborative optimal planning among multiple vehicles, resulting in the optimal drivable trajectories for both the ego vehicle and other vehicles under the given decision. Finally, an evaluation of the policy is conducted in terms of safety, comfort, and efficiency to select the optimal policy. In simulation experiments, the ICOPP demonstrates smoother and more stable autonomous driving performance compared to traditional methods.
A Mathematical-logic Perspective for Analyzing Machine Learning Models
Authors: Li Kechen
Published: October 2024

Machine learning (ML) has achieved remarkable success. There are various types of machine learning methods. However, the previous categorization of these models was simply based on the paradigm of learning. What kind of data and environment can be used for learning becomes the only concern, but whether the trained model is competent for a specific task is less discussed. Guiding ideology of what machine learning models are competent for a given application scenario is urgently needed. To solve this problem, we believe that this requires a logical analysis of the external properties of the learned models. In this paper, we propose a perspective for analyzing machine learning models by applying mathematical logic, which helps determine whether a model is up to a given task. In addition, we construct an analysis case and illustrate that the structural objects can be mapped to the class labels in machine learning. We believe this perspective will open a new field of analyzing machine learning with mathematical logic.
Compensation Algorithm for Wind Turbine Main Shaft Loads Based on LSTM
Authors: Wen Zecheng , Deng Yu , Wu Wei , Wen Hua , Chen Jikang
Published: October 2024

For wind turbine development, load size is the core and critical factor. Currently, most companies employ Bladed software for load calculations, which enjoys widespread use in engineering applications due to its efficiency and ease of use. However, constrained by the limitations of blade element theory and momentum theory, there still exist discrepancies between the simulation results and actual conditions. This paper aims to combine simulation algorithms with the application of an LSTM (Long Short-Term Memory) neural network to develop a compensation algorithm for the main shaft loads of wind turbines. By doing so, it endeavors to realize real-time monitoring of the main shaft loads, thereby providing a foundation for achieving high-precision control in wind turbine systems.
Rail State Recognition Method Based on a Convolutional Block Attention Module
Authors: Liu Lili , Zuo Jihong , Yang Chuanyin , Tang Yufeng
Published: October 2024

In order to solve the problems of high subjectivity and serious lag in traditional rail surface state recognition based on manual experience, a rail surface state recognition model based on convolution attention is proposed. First, the transfer learning method is used to pre-train the ImageNet data set to obtain the model parameters. Secondly, the 3×3 convolution in the ResNet-50 residual block is replaced with a convolutional block attention module (CBAM) to obtain a new CBAM-ResNet. Finally, the model identification results of the rail surface status are obtained through the Softmax classifier. The results show that this method can effectively identify the rail surface status, and the identification accuracy can reach 99.68%, which is better than other deep neural network models.