bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi-area Collision-free Path Planning and Efficient Task Scheduling Optimization for Autonomous Agricultural Robots
Authors: Yang Liwei , Li Ping , Wang Tao , Tian Jiya , Chen Chuangye , Tan Jie , Wang Zijian 
Published: April 2024

Abstract

Collision-free path planning and task scheduling optimization in multi-region operations of autonomous agricultural robots present a complex coupled problem. In addition to considering task access sequences and collision-free path planning, multiple factors such as task priorities, terrain complexity of farmland, and robot energy consumption must be comprehensively addressed. This study aims to explore a hierarchical decoupling approach to tackle the challenges of multi-region path planning. Firstly, we conduct path planning based on the A* algorithm to traverse paths for all tasks and obtain multi-region connected paths. Throughout this process, factors such as path length, turning points, and corner angles are thoroughly considered, and a cost matrix is constructed for subsequent optimization processes. Secondly, we reformulate the multi-region path planning problem into a discrete optimization problem and employ genetic algorithms to optimize the task sequence, thus identifying the optimal task execution order under energy constraints. We finally validate the feasibility of the multi-task planning algorithm proposed by conducting experiments in an open environment, a narrow environment and a large-scale environment. Experimental results demonstrate the method's capability to find feasible collision-free and cost-optimal task access routes in diverse and complex multi-region planning scenarios.
Influence of Vitamin D on the Prevention and Improvement of Symptomatic COVID-19: A Randomized, Open-labeled, Multicenter Trial
Authors: Wang Huan , Tao Liyuan , Cui Liyan , Chen Yahong , Liu Dongyang , Xue Lixiang , Yang Yuping , Lv Yang , Zhang Fuchun , Wang Tiancheng , Wang Xiaoxiao , Yuan Wanqiong , Liu Hao , Huang Jie , Jiang Yanfang , Liu Na , Yang Lijuan , Hu Yunjing , Li Yanfang , Gao Yuling , Li Haiyan , Li Baohua , Song Chunli 
Published: April 2024

Abstract

We aimed to investigate the preventive effect of vitamin D2 on COVID-19 and the improvement of symptoms after COVID-19 infection. The study recruited 228 health care workers who tested negative PCR or antigen for COVID-19. Subjects were randomly allocated to vitamin D2 or non-intervention at a ratio 1:1. Subjects recorded PCR or antigen tests and the symptoms of COVID-19 twice a week during the follow-up visit. The concentration of serum 25-hydroxyvitamin D (25(OH)D), C-reaction protein (CRP), complement component C1q and inflammatory cytokines were measured. The rates of COVID-19 infection were 50.5% in the vitamin D2 group and 52.4% in the non-intervention group (P= 0.785). There was no difference in the COVID-19 symptoms between the two groups. The mean 25(OH)D level significantly increased from 14.1 ng/mL to 31.1 ng/mL after administration (P <0.001). The difference between the two groups was not significant for the concentrations of CRP, C1q and inflammatory cytokines on the thirtieth day of thetrial. According to the second level of vitamin D, there was a 14.3% difference in positive infection rates between the vitamin D adequate (>30 ng/mL) and deficient groups (<20 ng/mL). Adequate vitamin D had a tendency to prevent COVID-19.
Trial registration
ClinicalTrials.gov NCT05673980, dated: 22/12/2022.
Revised constraints on the final stages of the last deglaciation from high-resolution sea-level observations
Authors: MUKHERJEE UDITA , Vetter Lael , Milne Glenn , Tarasov Lev , Steponaitis Elena , Cahill Niamh , Lecavalier Benoit , Rosenheim Brad , Tornqvist Torbjorn 
Published: April 2024

Abstract

The rapid transformation of the ocean-atmosphere-cryosphere system during the last deglaciation serves as a potential model for climate change during this century and beyond. Within this context, sea-level change can be viewed as the connecting tissue, but the limited resolution of relative sea-level (RSL) records has hindered progress toward closing the ice sheet–sea level budget since the Last Glacial Maximum, the partitioning of ice melt from different sources, and assessing the role of freshwater forcing in abrupt climate change. Here we present a new RSL record from the Mississippi Delta stretching back to 11 ka and combine it with the best available published RSL data worldwide for the final episode of the last deglaciation (9-7 ka). Glacial isostatic adjustment (GIA) modelling shows that these precise data constraints demand a North American ice melt of about 14 m sea-level equivalent (SLE) during this time, 4-10 m greater than previously estimated. Our results call for a major revision of the North American deglacial ice history and our findings demonstrate the utility of high-resolution RSL observations as a pathway towards closing the ice budget of the last deglaciation and improving our understanding of the ocean-atmosphere-cryosphere system during rapid climate change.
Numerical investigation on patterned two-phase microstructure for better mechanical properties
Authors: Zeng Liting , Ma Zhiwei , wei Yujie 
Published: April 2024

Abstract

In this study, two-dimensional composite of Cu/Ni laminated and brick-mortar structures were explored utilizing the GTN constitutive model and mathematical plane tessellation schemes. Uniaxial and biaxial stretching behaviors were analyzed by precisely controlling the model microgeometries and phase volume fraction characteristics, using finite element numerical simulations. The results show that the laminated structure represented by the triangular tessellation models exhibits stretching-dominated deformation when uniaxial stretching is carried out along the direction of the hard phase laminae and shows outstanding strength. The brick-mortar structure represented by the triangular tessellation models undergoes deformation in a combination of bending and stretching (compression), which helps to improve the plasticity yet avoid a significant decrease in strength. In addition, as the volume fraction of hard phase increases, the overall strength increases, but the plasticity decreases. When the volume fraction of hard phase is higher, the laminated structure represented by the triangular tessellation model is more prominent in terms of strength, whereas when the volume fraction of hard phase is lower, the brick-mortar structure represented by the triangular tessellation model is more prominent in terms of plasticity. Under biaxial conditions, the quadrangular tessellation scheme for brick-mortar structures shows better overall strength and plasticity. By analysing the microstructure-mechanical properties relationship in a two-phase composites, this study provides guidance for material synthesis through structural patterning.
Corpus-Based Study on Metadiscourse Markers in TESOL Research Articles
Authors: Bui Loan Thi Kim 
Published: April 2024

Abstract

Metadiscourse (MD) markers play an important role in helping readers follow the flow of discourse and get involved in the writer’s point of view. This study is aimed at investigating the employment of MD markers used in TESOL research articles based on Hyland’s (2005) categorization of MD markers into two types including interactive and interactional discourse markers. A total of 30 TESOL research articles collected from the proceedings of international TESOL conference held by a big university in Ho Chi Minh in 2021. The corpus of 30 TESOL research articles was analyzed with AntConc software and descriptive statistics. The findings reveal that the interactive discourse markers are used with a higher percentage than that of interactional discourse markers in TESOL research articles written by Vietnamese writers. Moreover, statistic results unravel that there is a difference in the quantity and function of MD markers in TESOL research articles written by Vietnamese writers. The study results are beneficial to novice research writers and teachers of English who are teaching academic writing.
Irregular Feature Enhancer for Low-dose CT Denoising
Authors: Deng Jiehang , Hu Zihang , He Jinwen , Liu Jiaxin , Qiao Guoqing , Gu Guosheng , Weng Shaowei 
Published: April 2024

Abstract

So far, deep learning based networks have been wildly applied in Low-Dose Computed Tomography (LDCT) image denoising. However, they usually adopt symmetric convolution to achieve regular feature extraction, but cannot effectively extract irregular features. Therefore, in this paper, an Irregular Feature Enhancer (IFE) focusing on effectively extracting irregular features is proposed by combining Symmetric-Asymmetric-Synergy Convolution Module (SASCM) with a hybrid loss module. Rather than simply stacking symmetric convolution layers used in traditional deep learning based networks, SASCM jointly utilizes symmetric and asymmetric convolution layers so as to effectively extract irregular tissue information of the image. In addition, the hybrid loss module is proposed to guide IFE to further mine the intrinsic feature information of the image from three perspectives: pixel point, high-level feature space, and gradient. The ablation experiments demonstrate the effectiveness and feasibility of SASCM and the hybrid loss. The quantitative experimental results also show that compared with several related LDCT denoising methods, the proposed IFE performs the best in terms of PSNR and SSIM. Furthermore, it can be observed from the qualitative visualization that the proposed IFE can recover the best image detail structure information among the compared methods.
Optimization of the Internal Structure of 3d-printed Components for Architectural Restoration
Authors: Tomei Valentina , Grande Ernesto , Imbimbo Maura 
Published: April 2024

Abstract

In recent years, 3D printing technology has assumed an important role in advanced construction processes across various engineering fields. Among these, the application to the architectural restoration of historic structures is particularly fascinating. The ability to precisely reproduce the shape and surface details of complex elements, combined with the availability of a wide range of printing materials, makes 3D printing technology competitive compared to traditional techniques. In this context, the internal volume structure of 3D printed elements represents an additional design parameter to consider for enhancing interventions in terms of reducing the required material, and thus, lowering costs and environmental impact. The paper presents the outcomes of experimental tests and numerical analyses conducted on plates, which represent portions of more complex elements produced by using Additive Manufacturing (AM) technology. These plates feature various internal configurations (such as reticular and rhomboidal patterns) derived from a mono-objective design optimization process. The experimental tests aim to analyze the influence of the configuration and the pattern on the behavior of printed samples. Additionally, the paper discusses insights derived from both theoretical models and Finite Element analyses, providing a clearer understanding of the experimental results.
MuDupNet: Multitasking Dual-Threshold Pointer Network for Point Cloud Alignment
Authors: Zhang Yingjie , Qiu Keyuan , Ren Zekai , Zhang Shun 
Published: April 2024

Abstract

Point cloud alignment is a core task in computer vision and robotics. To address the problems of inefficiency and insufficient interpretability often faced by existing methods when dealing with point clouds with complex local geometries, this paper proposes a model MuDupNet that combines traditional point cloud feature extraction methods and advanced deep learning techniques. This method employs a multi-task learning architecture, which is based on the regression of local geometric histogram features of the point cloud in the training phase, which enhances the deep interpretability of the network features and accuracy of the model, while a Dual-Threshold Pointer SVD (DPSVD) for point cloud alignment inference module is introduced to enhance the efficiency of the network in alignment. The experimental results show that the MuDupNet model exhibits excellent alignment accuracy and robustness on several standard datasets, especially when dealing with point cloud data with complex local geometries.
The Effect of Cerium Oxide Nanoparticles on Gamma-Ray Shielding Capacity of Vinyl Ester Resin: Experimental, MCNP6 and WinXCom Results
Authors: Erdönmez S. 
Published: April 2024

Abstract

The current study focused on investigating the gamma-ray shielding capacity of nano sized CeO2 (nCeO2) doped vinyl ester composites (VE/nCeO2) produced by the direct pouring method with different nCeO2 contents ranging from 2.5 to 20 wt%. X-ray Diffraction and Transmission Electron Microscopy were used to characterize the structural properties of nCeO2 particles. The gamma radiation shielding performance of the produced composites was investigated experimentally and theoretically within the scope of primary shielding coefficients like mass attenuation coefficient, half value layer, tenth value layer, mean free path, effective atomic number, and effective electron density. The experimental studies were obtained by NaI(Tl) scintillator detector for gamma-ray energies coming from Ba-133, Cs-137, and Co-60 radioactive point sources in the narrow beam geometry. The outcomes were compared with the theoretical calculations acquired by Monte Carlo N-Particle Transport version 6 code. The effective atomic number and effective electron density studies were additionally examined with WinXCom software. A good consistency between the experimental and theoretical outcomes was achieved. It was determined that among all composites, VE/20%nCeO2 composite having maximum nCeO2 content showed the best radiation shielding performance against all energy values. The nCeO2 additive was successful in enhancing the radiation attenuation performance of vinyl ester, and mass attenuation coefficients of investigated samples gradually changed from 0.15 to 0.79 cm2/g at 81 keV. The gamma-ray attenuation coefficients of the composites were compared with traditional shield materials and previously studied shielding materials and evaluated as promising lightweight, non-toxic alternatives for the low-energy gamma-ray shielding applications.
Non-Reciprocity in Photon Polarization based on direction of polarizer under Gravitational Fields
Authors: Ahn Doyeol , Noh Hansol , Alsing Paul , Miller Warner 
Published: April 2024

Abstract

Unification of gravity with quantum mechanics is still a terra incognita. Photon polarization measurements shed light in this quest, offering a unique perspective on the coexistence of these fundamental forces. We have revealed that non-reciprocity in the photon polarization angle can arise by tailoring the quantization axis, which corresponds to the direction of polarizer. Thanks to this non-reciprocity, the measured polarization angle along the quantization axis can become ten times larger than that of gravitationally induced frame rotation in both near-Earth and black hole environments. To verify this finding, we propose an astronomical interferometer composed of satellites with the tailored quantization axis, challenging the prevailing view of their triviality in closed paths of a photon. Notably, this non-reciprocity can extend to any additional rotation irrespective to the origin including non-relativistic rotation, quantum gravity, and the violation of Einstein equivalence principle. Our finding could offer new opportunities for testing fundamental principles in physics.
Experimental Study on Shear Failure Characteristics and Crack Propagation Laws of Rocks with Various Joint Angles under Hydro-Mechanical Coupling
Authors: Zhang Shichuan , Song shilong , Zhang Buchu , Shen Baotang , Chai Shunjie , Han Xuexian , Yang Huashuai 
Published: April 2024

Abstract

With the increasing depth of coal resource extraction, the surrounding rock in deep engineering faces a geological-mechanical environment characterized by high in-situ stress and elevated water pressure. Investigating the damage evolution and crack propagation patterns in jointed rock masses under the coupled effects of water and stress is crucial for understanding the destabilization and failure mechanisms of deep rock masses. This study employs equipment such as the ROCK TEST SYSTEM 816.01 shear apparatus and a force-thermal-water coupled shear test system to conduct a comprehensive investigation into the damage characteristics and shear crack propagation patterns of granite with varying joint angles under hydraulic coupling conditions.The research findings indicate that the injection of water pressure can effectively reduce the peak shear strength of granite by lowering the effective normal stress. As the joint angle increases, the peak shear strength of the specimens exhibits an overall "n"-shaped trend, with shear displacement showing a reversed "s"-shaped pattern, initially increasing, then decreasing, and increasing again at the peak. Both joint angle and water pressure significantly influence the damage incurred during the granite fracture process. With an increasing joint angle, the damage in the specimens demonstrates an initial increase, followed by a decrease, and then another increase. However, under the influence of water pressure, the damage in the specimens is higher compared to those without water pressure. The damage growth rate under water pressure follows a trend of initially increasing and then decreasing, with the maximum damage growth rate occurring at a joint angle of 30°.Furthermore, numerical simulations using the FRACOD software are conducted to simulate shear fracturing for the Yangba well in Enhanced Geothermal Systems (EGS) geothermal engineering. The results of the simulation calculations hold significant guidance for selecting wellbore positions in the target area of hot dry rocks.
Role of Computed Tomography in Measuring Peritumoral Fat Tissue for Preoperative Staging in Patients with Gastric Cancer
Authors: Ozcan Seray Gizem Gur , Erkan Merve , Ozyildirim Serra , Bilir Burak , Firat Yurdakul Deniz 
Published: April 2024

Abstract

Background
In patients with gastric cancer, staging is conducted using computed tomography during diagnosis. Distinguishing between early-stage and locally advanced tumors is particularly crucial for guiding the patient's treatment. Accurate staging with computed tomography depends on various factors, with the area of peritumoral fat tissue being the most significant, ensuring a precise understanding of serosal involvement. The aim of this study was to investigate the role of peritumoral fat tissue in the accurate staging of patients with local and locally advanced gastric cancer undergoing surgery.
Methods
A retrospective analysis was conducted on 165 patients who underwent gastric cancer surgery between 2017 and 2023. The patients’ demographic data, pathology results, tumor-lymph node-metastasis stages, and postoperative complications were examined. Utilizing the computed tomography scans taken during diagnosis, peritumoral fat tissue was measured in cm2.
Results
The mean value for peritumoral fat tissue was found to be 12.9 cm2. According to the receiver operating characteristic curve analysis, there was a significant correlation between the computed tomography staging and pathologic results of the patients with peritumoral fat tissue equal to or larger than 9.5 cm2, with a sensitivity of 87% and a specificity of 92% according to the Youden index (area under the curve: 0.923, p < 0.001).
Conclusion
This study has revealed that computed tomography can be used reliably in preoperative staging for patients with a peritumoral fat tissue area equal to or larger than 9.5 cm2.
Joint High-Precision Frequency and Code Phase Estimation Algorithm for Iridium NEXT Signals
Authors: Liu Yue , Xu Ying , Lei Ming , Gao Ming , Fang Zhibo , Jiang Cheng , Mao Yi 
Published: April 2024

Abstract

In recent years, Low Earth Orbit (LEO) satellite Signals of Opportunity (SOP) position technology has emerged as a crucial alternative to the Global Navigation Satellite System (GNSS), effectively addressing navigation and positioning challenges in the event of GNSS failure. Among numerous LEO constellations, Iridium NEXT garners significant attention due to its high-quality signals and extensive coverage. However, current signal estimation algorithms overlook the frequency shifts caused by satellite dynamics, thereby impacting the accuracy of signal demodulation results and Time-of-Arrival (TOA) estimation accuracy. Simultaneously, traditional TOA estimation methods face challenges of low accuracy and high complexity. To address these, the paper proposes a joint high-precision frequency and code phase estimation algorithm. By adjusting the phase deviation of synchronous signals, the algorithm mitigates the impact of high dynamics on signal estimation, and enhance estimation accuracy. Additionally, the algorithm utilizes the Early Minus Late Amplitude (EMLA) method for efficient TOA estimation. Experimental results demonstrate that, compared to existing signal estimation approaches, the proposed algorithm significantly enhances the positioning accuracy of Frequency Difference of Arrival (FDOA) by 36.1254% and 28.5289% in 220m short baseline and 20 km long baseline scenarios, respectively. Moreover, the algorithm allows for Time Difference of Arrival (TDOA) and FDOA fusion positioning, exhibiting markedly superior accuracy compared to FDOA positioning, with a maximum improvement of 53.0922%. The results also indicate a substantial enhancement in the stability and reliability of the differential position results.
Predictive value of methylene blue combined with indocyanine green in sentinel lymph node metastasis in breast cancer: a prospective pilot cohort study
Authors: He Zecheng , Guo Fan , Liu Yuhan , Wang Changjun , Zhou Yidong , Sun Qiang 
Published: April 2024

Abstract

Background:
The status of sentinel lymph nodes is crucial for prognosis and treatment decisions in breast cancer patients. This study aimed to evaluate the predictive value of combined methylene blue and indocyanine green for sentinel lymph node metastasis in breast cancer.
Methods:
This prospective cohort study enrolled 90 clinically node-negative breast cancer patients. Methylene blue and indocyanine green were injected locally before surgery. Sentinel lymph nodes were grouped based on fluorescence intensity and methylene blue staining. A binary logistic regression model was established using 285 lymph node groups to predict metastatic risk.
Results:
A total of 475 lymph nodes were identified, with 33 being metastatic. The metastatic risk reached 70% for partially blue-stained and weakly fluorescent lymph nodes between 1-2 cm. The model revealed associations between lymph node size, dye staining patterns, and metastatic risks (P<0.05). The AUC of the ROC curve was 0.855.
Conclusions:
The staining pattern of combined methylene blue and indocyanine green could predict risks of sentinel lymph node metastasis and facilitate rapid intraoperative identification of high-risk lymph nodes.