bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexible piezoelectric sensor based on polyvinylidene fluoride/polyacrylonitrile/carboxy-terminated multi-walled carbon nanotube composite films for human motion monitoring
Authors: Huang Yan , Li Yi , Yang Yanxin , Wu Yibo , Shi Qisong 
Published: February 2024

Abstract
Flexible piezoelectric devices have attracted much attention in the fields of intelligent devices and biomedicine because of their high sensitivity, stability, and flexibility. In this paper, a multifunctional flexible pressure sensor was prepared by adding polyacrylonitrile (PAN) and carboxylic-terminated multi-walled carbon nanotubes (c-MWCNTs) with polyvinylidene difluoride (PVDF) as the substrate. The β-phase content of PVDF/PAN blended fibers compounded with c-MWCNT was up to 95%. At the same time, when PAN was added, the mechanical properties of the composite fibers were constantly improved. The results show that the polymer blending method can improve the comprehensive properties of PVDF composite. The flexible sensor prepared from the PVDF/PAN/c-MWCNT composite film has an output voltage of 2.1 V and a current of 7 μA. The addition of c-MWCNT can largely improve the sensitivity of the sensor (4.19 V N−1). The sensor is attached to the finger and shows good output performance under different degrees of bending of the finger. The maximum output voltage of the sensor is 0.4 V, 0.56 V and 1.15 V when the finger bending angle is 30°, 60°, and 90°, respectively. Moreover, the developed piezoelectric sensor can monitor large-scale movements of various parts of the human body. Therefore, this composite material shows potential in areas such as motion monitoring and energy storage devices.
Assouad type dimensions of infinitely generated self-conformal sets
Authors: Banaji Amlan , Fraser Jonathan M 
Published: February 2024

Abstract
We study the dimension theory of limit sets of iterated function systems consisting of a countably infinite number of conformal contractions. Our focus is on the Assouad type dimensions, which give information about the local structure of sets. Under natural separation conditions, we prove a formula for the Assouad dimension and prove sharp bounds for the Assouad spectrum in terms of the Hausdorff dimension of the limit set and dimensions of the set of fixed points of the contractions. The Assouad spectra of the family of examples which we use to show that the bounds are sharp display interesting behaviour, such as having two phase transitions. Our results apply in particular to sets of real or complex numbers which have continued fraction expansions with restricted entries, and to certain parabolic attractors.
Sliding transformer with uncertainty estimation for vestibular schwannoma automatic segmentation
Authors: Liu Yang , Li Mengjun , Li Mingchu , Wang Xu , Liang Jiantao , Chen Ge , Feng Yuanjing , Chen Zan 
Published: February 2024

Abstract

Objective. Automated segmentation of vestibular schwannoma (VS) using magnetic resonance imaging (MRI) can enhance clinical efficiency. Though many advanced methods exist for automated VS segmentation, the accuracy is hindered by ambivalent tumor borders and cystic regions in some patients. In addition, these methods provide results that do not indicate segmentation uncertainty, making their translation into clinical workflows difficult due to potential errors. Providing a definitive segmentation result along with segmentation uncertainty or self-confidence is crucial for the conversion of automated segmentation programs to clinical aid diagnostic tools. Approach. To address these issues, we propose a U-shaped cascade transformer structure with a sliding window that utilizes multiple sliding samples, a segmentation head, and an uncertainty head to obtain both the segmentation mask and uncertainty map. We collected multimodal MRI data from 60 clinical patients with VS from Xuanwu Hospital. Each patient case includes T1-weighted images, contrast-enhanced T1-weighted images, T2-weighted images, and a tumor mask. The images exhibit an in-plane resolution ranging from 0.70 × 0.70 to 0.76 × 0.76 mm, an in-plane matrix spanning from 216 × 256 to 284 × 256, a slice thickness varying between 0.50 and 0.80 mm, and a range of slice numbers from 72 to 120. Main results. Extensive experimental results show that our method achieves comparable or higher results than previous state-of-the-art brain tumor segmentation methods. On our collected multimodal MRI dataset of clinical VS, our method achieved the dice similarity coefficient (DSC) of 96.08% ± 1.30. On a publicly available VS dataset, our method achieved the mean DSC of 94.23% ± 2.53. Significance. The method efficiently solves the VS segmentation task while providing an uncertainty map of the segmentation results, which helps clinical experts review the segmentation results more efficiently and helps to transform the automated segmentation program into a clinical aid diagnostic tool.
Semi-supervised iterative adaptive network for low-dose CT sinogram recovery
Authors: Wang Lei , Meng Mingqiang , Chen Shixuan , Bian Zhaoying , Zeng Dong , Meng Deyu , Ma Jianhua 
Published: February 2024

Abstract

Background. Concern has been expressed regarding the risk of carcinogenesis from medical computed tomography (CT) radiation. Lowering radiation in CT without appropriate modifications often leads to severe noise-induced artifacts in the images. The utilization of deep learning (DL) techniques has achieved promising reconstruction performance in low-dose CT (LDCT) imaging. However, most DL-based algorithms require the pre-collection of a large set of image pairs (low-dose/standard-dose) and the training of networks in an end-to-end supervised manner. Meanwhile, securing such a large volume of paired, well-registered training data in clinical practice is challenging. Moreover, these algorithms often overlook the potential to utilize the abundant information in a large collection of LDCT-only images/sinograms. Methods. In this paper, we introduce a semi-supervised iterative adaptive network (SIA-Net) for LDCT imaging, utilizing both labeled and unlabeled sinograms in a cohesive network framework, integrating supervised and unsupervised learning processes. Specifically, the supervised process captures critical features (i.e. noise distribution and tissue characteristics) latent in the paired sinograms, while the unsupervised process effectively learns these features in the unlabeled low-dose sinograms, employing a conventional weighted least-squares model with a regularization term. Furthermore, the SIA-Net method is designed to adaptively transfer the learned feature distribution from the supervised to the unsupervised process, thereby obtaining a high-fidelity sinogram through iterative adaptive learning. Finally, high-quality CT images can be reconstructed from the refined sinogram using the filtered back-projection algorithm. Results. Experimental results on two clinical datasets indicate that the proposed SIA-Net method achieves competitive performance in terms of noise reduction and structure preservation in LDCT imaging, when compared to traditional supervised learning methods.
3D-printed passive bellow actuator for portable soft wearable robots
Authors: Xia Jiutian , Li Yuanjing , Fu Shiling , Xie Wenhao , Qu Jingting , Li Yunquan , Ren Tao , Yang Yang , Liu Hao 
Published: February 2024

Abstract
The compliance of soft wearable robots driven by fluids is high, but their portability and controllability are limited due to complex fluidic systems. On the other hand, tendon-driven soft wearable robots are compact and easy to control, but they have lower compliance when actively interacting with unknown environments. To address this trade-off between compliance and controllability, we propose a novel actuator design for soft wearable robots, named the passive bellow actuator (PBA). The PBA is 3D-printed using elastic materials, which enables it to be easily customized into various shapes and sizes. When tendons running through the PBA are pulled, it contracts and preserves elastic potential energy. When the tendons are released, the PBA extends like a spring and exerts the stored elastic energy to drive the human body. Additionally, programmable deformation can be easily achieved by adjusting the thickness of the PBA chamber. By utilizing these effects, the PBA can be used to assist human flexion and extension movements. We developed a portable soft robotic glove to demonstrate the feasibility of the PBA. The glove is light weight, power safe, and is inherently compliant when grasping irregular objects. Theoretical modeling and experimental tests were conducted to characterize the PBA, and experimental tests were conducted to demonstrate the performance of the soft robotic gloves.
No X-Rays or Radio from the Nearest Black Holes and Implications for Future Searches
Authors: Rodriguez Antonio C. , Cendes Yvette , El-Badry Kareem , Berger Edo 
Published: February 2024

Abstract
Astrometry from the Gaia mission was recently used to discover the two nearest known stellar-mass black holes (BHs), Gaia BH1 and Gaia BH2. These objects are among the first stellar-mass BHs not discovered via X-rays or gravitational waves. Both systems contain ∼1 M
⊙ stars in wide orbits (a ≈ 1.4 au, 4.96 au) around ∼9 M
⊙ BHs, with both stars (solar-type main sequence star, red giant) well within their Roche lobes in Gaia BH1 and BH2, respectively. However, the BHs are still expected to accrete stellar winds, leading to potentially detectable X-ray or radio emission. Here, we report observations of both systems with the Chandra X-ray Observatory, the Very Large Array (for Gaia BH1) and MeerKAT (for Gaia BH2). We did not detect either system, leading to X-ray upper limits of L
X < 9.4 × 1028 and L
X < 4.0 × 1029 erg s−1 and radio upper limits of L

r
< 1.6 × 1025 and L

r
< 1.0 × 1026 erg s−1 for Gaia BH1 and BH2, respectively. For Gaia BH2, the non-detection implies that the accretion rate near the horizon is much lower than the Bondi rate, consistent with recent models for hot accretion flows. We discuss implications of these non-detections for broader BH searches, concluding that it is unlikely that isolated BHs will be detected via interstellar medium accretion in the near future. We also calculate evolutionary models for the binaries’ future evolution using Modules for Experiments in Stellar Astrophysics, and find that Gaia BH1 will be visible as a symbiotic BH X-ray binary for 5–50 Myr. Since no symbiotic BH X-ray binaries are known, this implies either that fewer than ∼104 Gaia BH1-like binaries exist in the Milky Way, or that they are common but have evaded detection.
Correlations in strong-field-emitted ultrashort electron pulses from metal needle tips
Authors: Meier S , Heimerl J , Hommelhoff P 
Published: February 2024

Abstract
When two electrons are emitted from a metal needle tip with the help of femtosecond laser pulses, they show a strong anticorrelation signal in the energy domain. Depending on the wavelength and intensity of the driving laser pulses, the electron emission process can be either in a perturbative regime, like single- or multi-photon photoemission, or in the strong-field regime, where emission is dominated by the instantaneous electric field of the laser pulse, or in the intermediate regime. Here, we report on the two-electron anticorrelation signal and how it evolves from the multiphoton toward the strong-field emission regime. We show that in both cases, the resulting anticorrelation signal can be well explained by semi-classical simulations using a point-particle model, thus the dynamics is dominated by the center-of-mass dynamics of the individual electrons. However, the actual emission process of multiple interacting electrons requires improved quantum mechanical models and therefore remains the subject of future work.
This paper is part of the Special Topic Collection: papers from the 31th Annual International Laser Physics Workshop 2023 (LPHYS 2023).
Refined symmetry-resolved Page curve and charged black holes*
Authors: Li 李 Pan 磐 , Ling 凌 Yi 意 
Published: February 2024

Abstract
The Page curve plotted using the typical random state approximation is not applicable to a system with conserved quantities, such as the evaporation process of a charged black hole, during which the electric charge does not macroscopically radiate out with a uniform rate. In this context, the symmetry-resolved entanglement entropy may play a significant role in describing the entanglement structure of such a system. We attempt to impose constraints on microscopic quantum states to match the macroscopic phenomenon of charge radiation during black hole evaporation. Specifically, we consider a simple qubit system with conserved spin/charge serving as a toy model for the evaporation of charged black holes. We propose refined rules for selecting a random state with conserved quantities to simulate the distribution of charges during the different stages of evaporation and obtain refined Page curves that exhibit distinct features in contrast to the original Page curve. We find that the refined Page curve may have a different Page time and exhibit asymmetric behavior on both sides of the Page time. Such refined Page curves may provide a more realistic description for the entanglement between the charged black hole and radiation during the evaporation process.
Connecting the unstable region of the entropy to the pattern of the Fisher zeros map
Authors: Rocha J C S , Costa B V 
Published: February 2024

Abstract
Phase transitions are one of the most interesting natural phenomena. For finite systems, one of the concerns in the topic is how to classify a specific transition as a being of first, second, or even of a higher order according to the Ehrenfest classification. The partition function provides all the thermodynamic information about the physical systems, and a phase transition can be identified using the complex temperature where it is equal to zero. In addition, the pattern of zeros in the complex temperature plane can provide evidence of the transition order. This manuscript presents an analytical and simulational study connecting the microcanonical analysis of the unstable region of the entropy to the canonical partition function zeros. We show that, for the first-order transition, the zeros accumulate uniformly in a vertical line on the complex inverse temperature plane as discussed in previous works. We illustrate our calculations using a 147 particles Lennard-Jones cluster.
On-scalp Yttrium-Iron Garnet sensor arrays for brain source localization: Cramér-Rao bound analysis
Authors: Razorenova A. , Skidchenko E. , Butorina A. , Koshev N. 
Published: February 2024

Abstract
A new type of highly sensitive Magnetometers based on Yttrium-Iron Garnet films (YIGM) is being designed and applied to brain signals recording. We modelled sensor arrays based on YIGM and well-established OPM (QuSpin Inc.) and SQUID (Elekta Neuromag) arrays used for magnetoencephalography (MEG). In this simulation study we investigate the inverse problem accuracy bound depending on the sensor arrays configuration, types of magnetometers and instrumental noise level. We estimate the variance of the probability of dipole source localization using the Cramér-Rao Lower Bound (CRLB); the CRLB is calculated with use of the numerical approximation of the forward model and its partial derivative parametrization. Our models confirm that the development of multi-channel YIG-MEG systems requires noise reduction, rather than an increase in number of sensors, to outperform OPM and SQUID arrays. The modelling showed the advantages of YIG-based gradiometry compared to conventional SQUID-system.
Relativistic calculation of the orbital hyperfine splitting in complex microscopic structures
Authors: Franzke K.L. , Schmidt W.G. , Gerstmann U. 
Published: February 2024

Abstract
Theoretical spectroscopy based on double perturbation theory is typically challenged by systems with large orbital hyperfine splitting. Therefore, we here derive a rigorous, non-perturbative scheme starting from Dirac’s equation which allows to calculate the contribution of the orbital HFI for complex structures including heavy atoms with strong spin-orbit coupling (SOC). Using the PAW formalism, the method has been implemented in the software package Quantum ESPRESSO. We show that the ‘orbital part’ actually scales with SOC strength if orbital quenching is hindered by low local symmetry, i.e. in case of dimers or atoms at surfaces. This holds true in particular when the unpaired electron is localized in quasi-atomic p-like orbitals. Here, the orbital part is by far not negligible, but becomes dominant by surpassing the dipolar contribution by a factor of five.
Divergent urban land trajectories under alternative population projections within the Shared Socioeconomic Pathways
Authors: McManamay Ryan A , Raad Alen , Vernon Chris R , Thurber Travis , Gao Jing , Powers Stephen , O’Neill Brian 
Published: February 2024

Abstract
Population change is a main driver behind global environmental change, including urban land expansion. In future scenario modeling, assumptions regarding how populations will change locally, despite identical global constraints of Shared Socioeconomic Pathways (SSPs), can have dramatic effects on subsequent regional urbanization. Using a spatial modeling experiment at high resolution (1 km), this study compared how two alternative US population projections, varying in the spatially explicit nature of demographic patterns and migration, affect urban land dynamics simulated by the Spatially Explicit, Long-term, Empirical City development (SELECT) model for SSP2, SSP3, and SSP5. The population projections included: (1) newer downscaled state-specific population (SP) projections inclusive of updated international and domestic migration estimates, and (2) prevailing downscaled national-level projections (NP) agnostic to localized demographic processes. Our work shows that alternative population inputs, even those under the same SSP, can lead to dramatic and complex differences in urban land outcomes. Under the SP projection, urbanization displays more of an extensification pattern compared to the NP projection. This suggests that recent demographic information supports more extreme urban extensification and land pressures on existing rural areas in the US than previously anticipated. Urban land outcomes to population inputs were spatially variable where areas in close spatial proximity showed divergent patterns, reflective of the spatially complex urbanization processes that can be accommodated in SELECT. Although different population projections and assumptions led to divergent outcomes, urban land development is not a linear product of population change but the result of complex relationships between population, dynamic urbanization processes, stages of urban development maturity, and feedback mechanisms. These findings highlight the importance of accounting for spatial variations in the population projections, but also urbanization process to accurately project long-term urban land patterns.
Composition of Arthropods in Conventional and Surjan Systems in the Special Region of Yogyakarta
Authors: Wagiyana  , Alfarisy F K , Suharto  , Khozin M N , Habriantono B , Abdillah T , Nurdika A A H 
Published: February 2024

Abstract
Arthropods are the most abundant phylum found in plant ecosystems. The surjan planting system is sustainable agroecosystem engineering. The surjan system is one of the local cultural wisdom for dealing with pest and plant disease problems. In contrast to conventional systems, the majority of cultivation processes apply a monoculture farming system with massive use of pesticides and fertilizers. The research aims to determine the composition of arthropods from the application of surjan and conventional systems. The research was conducted in the Special Region of Yogyakarta in August 2022. The tools and materials used consisted of an inverter microscope, yellow trap, pitfall trap, pheromone trap, 70% alcohol, Taxofone, insect needles, vials and methyl eugenol. Each type of trap was repeated four times and designed diagonally. The collected arthropods were then observed using an inverter microscope. The identification results of Bactrocera sp and Atherigona sp are the dominant species found in the Bantul and Kulonprogo districts. The composition of arthropods in conventional land (Bantul Regency) is greater than in the surjan system (Kulonprogo Regency) based on population natural enemies. In contrast to the status of natural enemies, the surjan system has more natural enemies than conventional systems.
Carbon stock estimation of Sonneratia alba in mangrove restoration area in Pasar Rawa, Langkat North Sumatera
Authors: Harefa M S , Nasution Z , Tuhono E , Susilowati A , Wulandari W 
Published: February 2024

Abstract
Mangrove forests must be protected because they are an important ecosystem for climate mitigation. Mangrove forests are one of the “blue carbon” ecosystems capable of absorbing significantly more carbon than terrestrial forests. Mangrove restoration is being carried out in various regions as part of an effort to rehabilitate damaged ecosystems, one of which being Pasar Rawa Village in Langkat Regency. Sonneratia alba is a native plant that is employed in restoration activities. The purpose of this study is to investigate carbon stock in the S. alba monoculture restoration area in Pasar Rawa Village, Langkat Regency, North Sumatra Province. Purposive sampling was employed in this study, with plots distributed evenly around the research area. Carbon stock estimation is performed non-destructively by estimating carbon estimates based on diameter at breast height (DBH) and total height of trees. According to the research findings, the total carbon stored in the Sonneratia alba restoration area is quite low, at 60.89 ton.ha−1. S. alba produced 192.13 ton.ha−1 of absorbed carbon with CO2 absorption of 19212.84 g/m2 and so was classified as low.
Impact of giving vermicompost and goat manure compost to soil N, P, K nutrients, growth and production of mustard greens (Brassica juncea L.)
Authors: Marbun P , Razali  , Syahputra R 
Published: February 2024

Abstract
The excessive and prolonged use of synthetic fertilizers in mustard greens cultivation can lead to soil and plant degradation. To address this issue, alternative methods to enhance soil nutrients, such as incorporating organic fertilizers like vermicompost and goat manure compost, can be employed. This study aims to investigate the effects of applying vermicompost and goat manure compost on soil nutrients (N, P, K), the growth and yield of mustard greens (Brassica juncea L.). Conducted at the experimental field in Medan Selayang and Sumatera Utara Agricultural Technology Research Laboratory from February to May 2020, the research utilized a non-factorial randomized block design (RBD) with various treatments. These treatments included a control group (no fertilizer), recommended dose (goat manure 10 ton/ha + Urea 130 kg/ha) as comparison, vermicompost at 10, 20, and 30 ton/ha, and goat manure compost at 10, 20, and 30 ton/ha. The result indicated that the application of vermicompost and goat manure compost led to increased levels of C-organic, N-total, P-available, K-exchange, the number of mustard greens leaves, and mustard greens production. Vermicompost outperformed goat manure compost in enhancing K-exchange, the number of mustard greens leaves, and mustard greens production. The best treatment is giving vermicompost 20 ton/ha.