bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust RGB: D-SLAM in highly dynamic environments based on probability observations and clustering optimization
Authors: Liu Hailin , Tian Liangfang , Du Qiliang , Xu Wenjie 
Published: December 2023

Abstract
Visual simultaneous localization and mapping (SLAM) is the underlying support of unmanned systems. Currently, most visual SLAM methods are based on the static environment assumption so that dynamic objects in the camera’s field of view will seriously disrupt its working performance. In view of this, an RGB-D SLAM approach based on probability observations and clustering optimization for highly dynamic environments is proposed, which can effectively eliminate the influence of dynamic objects and accurately estimate the ego-motion of an RGB-D camera. The method contains a dual static map point detection strategy, which is carried out simultaneously in the current and previous frames. First, to enhance tracking robustness in highly dynamic environments, the probabilities of map points being static, calculated by both reprojection deviation and intensity deviation, are used to weight the cost function for pose estimation. Meanwhile, by taking the previous frames as a reference, a static velocity probability based on sparse scene flow is acquired to preliminarily recognize static map points and further improve the tracking accuracy. Then, an improved map point optimization strategy based on K-means clustering is designed, which effectively takes advantage of the clustering algorithm to refine the static map point labels while alleviating its stubborn problem. Finally, the experimental results on the TUM dataset and real scenes compared with the state-of-the-art visual SLAM methods illustrate that the proposed method achieves an extremely robust and accurate performance for estimating camera pose in highly dynamic environments.
Fusing sensitive degradation features with uncertainty analysis for RUL prediction of rotating machines
Authors: Li Yuxin , Liu Jie , Liu Baonan , Zhang Fengyuan , Yuan Xiaohui , Zhang Yongchuan 
Published: December 2023

Abstract
Recently, deep learning technology-based neural networks have been adopted for remaining useful life (RUL) prediction of rotating machines. However, there are still some shortcomings: (1) an individual degradation feature cannot sufficiently represent the degradation process, which has an adverse impact on the accuracy of prediction results; (2) most recurrent neural network-based prediction methods have difficulty in quantifying the uncertainty of the forecast results. In this paper, a fusing sensitive degradation features with uncertainty analysis for RUL prediction of rotating machines is proposed. Firstly, the statistical features contained in the vibration signal used to monitor the degradation of rotating equipment are extracted to construct the original feature set. Then, the weight coefficients of the monotonicity, correlation and robustness criteria are determined by the self-adjusting analytic hierarchy process. The sensitive features that describe the degradation process are selected from among the statistical features. Furthermore, the sensitive features are fed into residual networks and gated recurrent unit, and the spatial and temporal correlation of the features are considered to establish the health index (HI). Finally, the fitted HI is input into a Gaussian process regression model, and the prediction results with confidence intervals are obtained. To verify the effectiveness and superiority of the proposed method, two public bearing datasets and three model methods are used for comparative experiments.
Fault diagnosis method for planetary gearbox based on intrinsic feature extraction and attention mechanism
Authors: Zhan Shanning , Shao Ruipeng , Men Chengjie , Hao Huimin , Wu Zhifei 
Published: December 2023

Abstract
In a high-noise environment and with a limited number of faulty samples, it becomes challenging to extract a sufficient amount of useful fault information, which makes gear fault diagnosis more difficult. To address these issues, this paper proposes a fault diagnosis method for planetary gearboxes based on intrinsic feature extraction and attention mechanism. The method utilizes the complementary ensemble empirical mode decomposition algorithm to perform modal decomposition on the fault vibration signal, obtaining a series of modal components. By comparing and selecting the modal components that contain a significant amount of fault features, they are then transformed into two-dimensional images with time–frequency properties using wavelet transform. Additionally, a neural network model based on attention mechanism and large-scale convolution is proposed. The preprocessed images are inputted into the network for feature extraction. During this process, the large-scale convolution with residual structure maximizes the retention of effective feature information, while the attention network further filters the features. Finally, the selected features are used for fault classification. The model is validated using the gear datasets from Southeast University and the University of Connecticut. A comparison is made with the Pro-MobileNetV3, channel attention and multiscale convolutional neural network, multiscale dynamic adaptive residual network, and CBAM-ResNeXt50 models. It is found that the accuracy reaches 100% before adding Gaussian noise and 99.68% after adding noise, which is significantly higher than that of other models.
Designer artificial chiral kagome lattice with tunable flat bands and topological boundary states
Authors: Li Xueyan , Wang Dongli , Hu Hao , Pan Yi 
Published: December 2023

Abstract
The kagome lattice is a well-known model system for the investigation of strong correlation and topological electronic phenomena due to the intrinsic flat band, magnetic frustration, etc. Introducing chirality into the kagome lattice would bring about new physics due to the unique symmetry, which is still yet to be fully explored. Here we report the investigation on a two-dimensional chiral kagome lattice utilizing tight binding band calculation and topological index analysis. It is found that the periodic chiral kagome lattice would bring about a robust zero-energy flat band. Furthermore, in the Su–Schrieffer–Heeger type dimer-/trimerized breathing chiral kagome lattice with particular edge terminations, topological corner states or metallic edge states would appear, implying new candidates for the second-order topological insulator. We also proposed the construction strategy for such lattices employing the scanning tunneling microscope atom manipulation technique.
Ketoconazole-loading strategy to improve antifungal activity and overcome cytotoxicity on human renal proximal tubular epithelial cells
Authors: Coksu Irem , Bozkurt Yagmur , Akmayan Ilkgul , Demirci Hasan , Ozbek Tulin , Acar Serap 
Published: December 2023

Abstract
Ketoconazole (KTZ), an antifungal agent used to treat localized or systemic fungal infections by inhibiting ergosterol synthesis, exhibits restricted efficacy within eukaryotic cells owing to its elevated toxicity and limited solubility in water. This study aims to improve the biological activity and overcome cytotoxic effects in the renal system of the hydrophobic KTZ by incorporating it into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) utilizing biomaterial nano-engineering techniques. KTZ-loaded PLGA NPs (KTZ-NPs) were prepared by single emulsion solvent evaporation method and characterized by using dynamic light scattering (DLS), electrophoretic light scattering (ELS), Fourier transform-infrared (FT-IR) spectroscopy and scanning light microscopy (SEM). Particle size and zeta potential of KTZ-NPs were determined as 182.0 ± 3.27 nm and −27.4 ± 0.56 mV, respectively. Antifungal activity was analyzed with the time-kill and top agar dilution methods on Candida albicans (C. albicans) and Aspergillus flavus (A. flavus). Both KTZ and KTZ-NPs caused a significant decrease in A. flavus cell growth; however, the same effect was only observed in time-killing analysis on C. albicans, indicating a methodological difference in the antifungal analysis. According to the top agar method, the MIC value of KTZ-NPs against A. flavus was 9.1 μg ml−1, while the minimum inhibition concentration (MIC) value of KTZ was 18.2 μg ml−1. The twofold increased antifungal activity indicates that nanoparticular drug delivery systems enhance the water solubility of hydrophobic drugs. In addition, KTZ-NPs were not cytotoxic on human renal proximal tubular epithelial cells (HRPTEpCs) at fungistatic concentration, thus reducing fungal colonization without cytotoxic on renal excretion system cells.
Predictable and adjustable broadband gold nanorods for photothermal effects and foldable performances
Authors: Chen Xi , Liu Jie , Li Xun , Cheng Zhiqun , Deng Tian-Song 
Published: December 2023

Abstract
Colloidal gold nanorods (GNRs) have demonstrated their potential to absorb light within specific wavelength bands and induce photothermal effects. However, the unpredictability and lack of adjustability in the broadband spectrum formed by the self-assembly of gold nanospheres or the coupling of various sizes of GNRs have posed significant challenges. To address this, we have developed broadband GNRs (BGNRs) with a predictable and adjustable extinction band in the visible and near-infrared regions. The BGNRs were synthesized by simply mixing GNRs with different aspect ratios, allowing for control over the bandwidths and positions of the extinction bands. Subsequently, the BGNRs were coated with silica and underwent surface modification. The resulting BGNRs@SiO2 were then mixed with either polydimethylsiloxane (PDMS) or polyvinylidene fluoride (PVDF) to create BGNRs@SiO2/PDMS (or PVDF) films. The BGNRs@SiO2/PDMS and BGNRs@SiO2/PVDF films both exhibit excellent photothermal performance properties. Additionally, the light absorption intensity of the BGNRs@SiO2/PVDF film linearly increases upon folding, leading to significantly enhanced photothermal performance after folding. This work demonstrates that plasmonic colloidal GNRs, without the need for coupling, can yield predictable and adjustable extinction bands. This finding holds great promise for future development and practical applications, particularly in the transfer of these properties to films.
Ultrasound stimulated piezoelectric barium titanate and boron nitride nanotubes in nonconductive poly-ε-caprolactone nanofibrous scaffold for bone tissue engineering
Authors: Çobandede Zehra , Çulha Mustafa 
Published: December 2023

Abstract
Nanomaterials can provide unique solutions for the problems experienced in tissue engineering by improving a scaffold’s physico-bio-chemical properties. With its piezoelectric property, bone is an active tissue with easy adaptation and remodeling through complicated mechanisms of electromechanical operations. Although poly(ε-caprolactone) (PCL) is an excellent polymer for bone tissue engineering, it is lack of conductivity. In this study, piezoelectric barium titanates (BaTiO3) and boron nitride nanotubes (BNNTs) are used as ultrasound (US) stimulated piezoelectric components in PCL to mimic piezoelectric nature of bone tissue. Electric-responsive Human Osteoblast cells on the scaffolds were stimulated by applying low-frequency US during cell growth. Biocompatibility, cell adhesion, alkaline phosphatase activities and mineralization of osteoblast cells on piezo-composite scaffolds were investigated. BaTiO3 or BNNTs as reinforcement agents improved physical and mechanical properties of PCL scaffolds. In vitro studies show that the use of BaTiO3 or BNNTs as additives in non-conductive scaffolds significantly induces and increases the osteogenic activities even without US stimulation. Although BaTiO3 is one of the best piezoelectric materials, the improvement is more dramatic in the case of BNNTs with the increased mineralization, and excellent chemical and mechanical properties.
Therapeutic effect and metabolic fingerprinting of triple-negative breast cancer cells following exposure to a novel pH-responsive, gambogic acid-loaded micelle
Authors: Da Mengting , Li Su , Yang Rui , Jia Zhen , Ma Yulian , Qi Fengxian , Zhao Jiuda , Shen Guoshuang , Chen Daozhen 
Published: December 2023

Abstract
Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis and lacks effective therapeutic targets. The use of gambogic acid (GA), a class of active ingredients in traditional Chinese medicine with anti-tumour potential, is limited in tumour therapy owing to its drawbacks and unclear organ toxicity. In this study, we used the pH-responsive amphiphilic block copolymer, PEOz-PCL, to create nanodrugs for GA delivery to MDA-MB-231 cells. The pH-responsive GA-loaded micelles were prepared through nanoprecipitation with a more homogeneous size. The average particle size was 42.29 ± 1.74 nm, and the zeta potential value was 9.88 ± 0.17 mV. The encapsulation rate was 85.06%, and the drug loading rate was 10.63%. The process was reproducible, and sustained release reached 80% in 96 h at acid pH 5.0. Furthermore, cellular tests using CCK-8, TUNEL, and flow cytometry revealed that pH-responsive GA-loaded micelles killed MDA-MB-231 cells more effectively and had much higher activity and targeting compared with free drugs. Metabolomic analysis of the changes in differential metabolites revealed that pH-responsive GA-loaded micelles may inhibit TNBC cells by causing amino acid anabolism, nucleotide metabolism, and glucose metabolism, as well as by affecting their energy sources. The study outcomes will help understand the mechanism of action and the therapeutic efficacy of pH-responsive GA-loaded micelles in vivo.
A road map to the blow-up for a Kirchhoff equation with external force
Authors: Ghisi Marina , Gobbino Massimo 
Published: December 2023

Abstract
It is well-known that the classical hyperbolic Kirchhoff equation admits infinitely many simple modes, namely time-periodic solutions with only one Fourier component in the space variables. In this paper we assume that, for a suitable choice of the nonlinearity, there exists a heteroclinic connection between two simple modes with different frequencies. Under this assumption, we cook up a forced Kirchhoff equation that admits a solution that blows-up in finite time, despite the regularity and boundedness of the forcing term. The forcing term can be chosen with the maximal regularity that prevents the application of the classical global existence results in analytic and quasi-analytic classes.
Research on variable stiffness asymmetrical resonant linear piezoelectric actuator based on multi-modal drive
Authors: He Liangguo , Yue Xukang , Dou Haotian , Ge Xinfang , Wan Zhikai , Qian An 
Published: December 2023

Abstract
In this paper, a linear piezoelectric motor with variable stiffness and asymmetric resonance is proposed, which is driven by a single harmonic signal. Working in the resonant state improve the output performance of the motor. Motor control is relatively simple and can realize reverse movement under the driving of second-order single harmonic signal. At the same time, the new motor can obtain different operating speed and step distance by changing the clamping position in front and back to meet the requirements of different loads and different working conditions and has strong applicability. By experiment, the first-order optimal operating frequency of the motor prototype at three different stiffness adjustment positions is 88 Hz, 90 Hz and 92 Hz respectively. Under the excitation of 240 Vp–p first-order resonance signal, the corresponding output speed of the motor prototype is 16.116 mm s−1, 20.457 mm s−1 and 25.015 mm s−1 respectively, and the corresponding displacement resolution is 0.18 mm, 0.22 mm and 0.27 mm respectively. When the stiffness adjustment positions is 2 mm, the maximum load of the motor prototype reaches 450 g. The second-order optimal operating frequency at the stiffness adjustment positions 1 mm is 601 Hz. Under the excitation of a 240 Vp–p second-order resonant signal, the reverse output speed of the motor prototype is 13.126 mm s−1, and the corresponding displacement resolution is 0.02 mm.
A versatile and high-load soft gripper enabled by vacuum-assisted bio-inspired interfacial adhesion
Authors: Sun Tianhui , Chen Wenqing , Li Jingyang , Li Xiaosong , Li Xinxin , Meng Yonggang , Tian Yu 
Published: December 2023

Abstract
Soft robotic grippers have gained considerable attention owing to their highly compliant, adaptive, and safe characteristics in a large variety of scenes, especially involving human-machine interactions. However, the low-stiffness nature of the soft material and the multi-finger gripping mechanism make soft grasping systems suffer in applications requiring relatively high load capacity and broad grasping adaptability. Despite extensive efforts to develop soft grippers with tunable stiffness by constructing smart materials and structures, the resultant load capacity is often compromised by sacrificing working efficiency or surface adaptability. In this work, we report a paradigm to design a versatile, high-load (>2 kg), and fast-response (<1 s) pneumatic soft gripper by strengthening the contact interface via bio-inspired controllable adhesion. A mushroom-shaped micropatterned dry adhesive surface is integrated with a soft pneumatic bidirectionally bendable actuator via a vacuum-assisted equal load-sharing design. This gripper extends the adaptable object diameter from 15 mm to infinity and significantly increases the load capacity to over 2 kg without compromising the original compliance. The multifunctional grasping modes and high load capacity are successfully demonstrated by grasping objects with diverse material components, various surface shapes.
Engineered IPMC sensors: modeling, characterization, and application towards wearable postural-tactile measurement
Authors: Nagel William S , Fakharian Omid , Aureli Matteo , Leang Kam K 
Published: December 2023

Abstract
This paper focuses on the modeling and development of engineered ionic polymer-metal composite (eIPMC) sensors for applications such as postural and tactile measurement in mechatronics/robotics-assisted finger rehabilitation therapy. Specifically, to tailor the sensitivity of the device, eIPMCs, fabricated using a polymer-surface abrading technique, are utilized as the sensing element. An enhanced chemoelectromechanical model is developed that captures the effect of the abrading process on the multiphysics sensing behavior under different loading conditions. The fabricated sensors are characterized using scanning electron microscopy imaging and cyclic voltammetry and chronoamperometry. Results show significant improvement in the electrochemical properties, including charge storage, double layer capacitance, and surface conductance, compared to the control samples. Finally, prototype postural-tactile finger sensors composed of different eIPMC variants are created and their performance validated under postural and tactile experiments. The tailored eIPMC sensors show increased open-circuit voltage response compared to control IPMCs, with 7.7- and 4.7-times larger peak-to-peak bending response under postural changes, as well as a 3.2-times more sensitive response under compression during tactile loading, demonstrating the feasibility of eIPMC sensors.
Dynamically reprogrammable stiffness in gecko-inspired laminated structures
Authors: Chen Kai Jun , Sakovsky Maria 
Published: December 2023

Abstract
Adaptive structures are of interest for their ability to dynamically modify mechanical properties post fabrication, enabling structural performance that is responsive to environmental uncertainty and changing loading conditions. Dynamic control of stiffness is of particular importance as a fundamental structural property, impacting both static and dynamic structural performance. However, existing technologies necessitate continuous power to maintain multiple stiffness states or couple stiffness modulation to a large geometric reconfiguration. In this work, reversible lamination of stiff materials using gecko-inspired dry adhesives is leveraged for bending stiffness control. All stiffness states are passively maintained, with electrostatic or magnetic actuation applied for ∼1 s to reprogram stiffness. We demonstrate hinges with up to four passively maintained reprogrammable states decoupled from any shape reconfiguration. Design guidelines are developed for maximizing stiffness modulation. Experimentally, the proposed method achieved a stiffness modulation ratio of up to 14.4, with simulations showing stiffness modulation ratios of at least 73.0. It is anticipated that the stiffness reprogramming method developed in this work will reduce energy requirements and design complexity for adaptation in aerospace and robotics applications.
Nonlinear dynamics of 3D superconducting maglevs with six degrees of freedom: dependence on magnetization strategy and disturbance type
Authors: Huang Chenguang , Diao Yunfei , Liu Yi , Chen Long , Liu Wei , Tao Weifeng , Wang Fusheng 
Published: December 2023

Abstract
Based on the heat diffusion equation, Maxwell’s equations, and translational and rotational dynamic equations, we establish and theoretically validate an electromagnetic-thermal-mechanical coupling model to analyze the levitation performance during normal operation and the nonlinear dynamic behavior under disturbance for 3D maglev systems composed of a six-degree-of-freedom bulk superconductor (SC) and a Halbach-type guideway of permanent magnets (PMs) with different magnetization strategies and different types of disturbances, as well as the change rules of magnetic force and torque during translational or rotational cycle movement. In order to ensure the system security, we propose a generalized electromagnetic restoring force model to theoretically analyze the stability of the SC moving along the directions of various degrees of freedom. The results show that after being disturbed, the SC vibrates along the direction of each degree of freedom, and the vibration center, i.e. equilibrium position, will drift along each vibration direction. With time increasing, the equilibrium position will appear periodically on both sides of the working position. Compared to zero-field cooling magnetization, field cooling magnetization enables the SC to trap more flux in its interior to alleviate the drift phenomenon and reduce the energy loss. This advantage can be further enhanced by adding an extra step of preloading treatment. For the lateral motion, the system has one stable focus point and two unstable saddle points. Whether the system at these saddle points is stable depends on the direction of disturbance-induced velocity. For the rotational motion, the system has only one stable focus point, which means that regardless of the type of disturbance, the SC will finally come back to its stable equilibrium position. Besides, the stability is related to the axis around which the SC rotates, and rotating around the longitudinal axis is more likely to generate larger magnetic force, torque and local temperature rise. Either field cooling magnetization or preloading treatment can effectively improve system stability.
Analogue tachyons in SNAIL transmission lines
Authors: Katayama Haruna , Hatakenaka Noriyuki , Fujii Toshiyuki , Blencowe Miles P 
Published: December 2023

Abstract
Tachyons are hypothetical particles with imaginary mass that travel faster than light. However, methods to experimentally verify whether tachyons exist are lacking. Here, we propose a novel scheme to create analogue tachyons using a transmission line composed of superconducting nonlinear asymmetric inductive elements and to detect them by controlling the wavenumber in order to extend their lifetime. In particular, we numerically demonstrate the exotic property of tachyons where their velocity increases with decreasing energy. Our proposal offers a promising approach to understanding tachyon condensation, which is crucial for elucidating the origins of the Universe, in a realizable laboratory system.