bluuebunny/crossref_metadata_2025_split huggingface dataset:
Do the majority of stars form as gravitationally unbound?
Authors: Dinnbier František , Kroupa Pavel , Anderson Richard I. 
Published: January 2022

Context. Some of the youngest stars (age ≲ 10 Myr) are clustered, while many others are observed scattered throughout star forming regions or in complete isolation. It has been intensively debated whether such scattered or isolated stars originate in star clusters or whether they form in truly isolated conditions. Exploring these scenarios could help set constraints on the conditions in which massive stars are formed.
Aims. We adopted the assumption that all stars form in gravitationally bound star clusters embedded in molecular cloud cores (Γ-1 model), which expel their natal gas early after their formation. Then we compared the proportion (fraction) of stars found in clusters with observational data.
Methods. The star clusters are modelled by the code NBODY6, which includes binary stars, stellar and circumbinary evolution, gas expulsion, and the external gravitational field of their host galaxy.
Results. We find that small changes in the assumptions in the current theoretical model estimating the fraction, Γ, of stars forming in embedded clusters have a large influence on the results, and we present a counterexample as an illustration. This calls into question theoretical arguments about Γ in embedded clusters and it suggests that there is no firm theoretical ground for low Γ in galaxies with lower star formation rates (SFRs). Instead, the assumption that all stars form in embedded clusters is in agreement with observational data for the youngest stars (age ≲ 10 Myr). In the Γ-1 scenario, the observed fraction of the youngest stars in clusters increases with the SFR only weakly; the increase is caused by the presence of more massive clusters in galaxies with higher SFRs, which release fewer stars to the field in proportion to their mass. The Γ-1 model yields a higher fraction of stars in clusters for older stars (ages between 10 Myr and 300 Myr) than what is observed. This discrepancy can be caused by initially less compact clusters or a slightly lower star-formation efficiency than originally assumed in the Γ-1 model, or by interactions of the post-gas-expulsion revirialised open clusters with molecular clouds.
The origin of the high metallicity of close-in giant exoplanets
Authors: Shibata S. , Helled R. , Ikoma M. 
Published: January 2022

Context. The composition of gas giant planets reflects their formation and evolution history. Revealing the origin of the high heavy-element masses in giant exoplanets is an objective of planet formation theories. Planetesimal accretion during the phase of planetary migration could lead to the delivery of heavy elements into gas giant planets. In our previous paper, we used dynamical simulations and showed that planetesimal accretion during planetary migration occurs in a rather narrow region of the protoplanetary disk, which we refer to as the “sweet spot” for accretion.
Aims. Our understanding of the sweet spot, however, is still limited. The location of the sweet spot within the disk and how it changes as the disk evolves were not investigated in detail. The goal of this paper is to reveal the nature of the sweet spot using analytical calculations and to investigate the role of the sweet spot in determining the composition of gas giant planets.
Methods. We analytically derived the required conditions for the sweet spot. Then, using the numerical integration of the orbits of planetesimals around a migrating planet, we compared the derived equations with the numerical results.
Results. We find that the conditions required for the sweet spot can be expressed by the ratio of the aerodynamic gas damping timescale of the planetesimal orbits to the planetary migration timescale. If the planetary migration timescale depends on the surface density of disk gas inversely, the location of the sweet spot does not change with the disk evolution. We expect that the planets observed inner to the sweet spot include a much greater amount of heavy elements than the planets outer to the sweet spot. The mass of planetesimals accreted by the protoplanet in the sweet spot depends on the amount of planetesimals that are shepherded by mean motion resonances. Our analysis suggests that tens Earth-masses of planetesimals can be shepherded into the sweet spot without planetesimal collisions. However, as more planetesimals are trapped into mean motion resonances, collisional cascade can lead to fragmentation and the production of smaller planetesimals. This could affect the location of the sweet spot and the population of small objects in planetary systems.
Conclusions. We conclude that the composition of gas giant planets depends on whether the planets crossed the sweet spot during their formation. Constraining the metallicity of cold giant planets, which are expected to be beyond the sweet spot, with future observations would reveal key information for understanding the origin of heavy elements in giant planets.
Physicians' Views on Utilization of an Electronic Health Record–Embedded Calculator to Assess Risk for Venous Thromboembolism among Medical Inpatients: A Qualitative Study
Authors: Moss Stephanie R. , Martinez Kathryn A. , Nathan Cassandra , Pfoh Elizabeth R. , Rothberg Michael B. 
Published: January 2022

Abstract
Background Venous thromboembolism (VTE) causes preventable in-hospital morbidity. Pharmacologic prophylaxis reduces VTE in at-risk patients but also increases bleeding. To increase appropriate prescribing, a risk calculator to guide prophylaxis decisions was developed. Despite efforts to promote its use, providers accessed it infrequently.
Objective This study aimed to understand provider perspectives on VTE prophylaxis and facilitators and barriers to using the risk calculator.
Design This is a qualitative study exploring provider perspectives on VTE prophylaxis and the VTE risk calculator.
Participants We interviewed attending physicians and advanced practice providers who used the calculator, and site champions who promoted calculator use. Providers were categorized by real-world usage over a 3-month period: low (<20% of the time), moderate (20–50%), or high (>50%).
Approach During semistructured interviews, we asked about experiences with VTE, calculator use, perspectives on its implementation, and experiences with other risk assessment tools. Once thematic saturation was reached, transcripts were analyzed using content analysis to identify themes.
Results Fourteen providers participated. Five were high utilizers, three were moderate utilizers, and six were low utilizers. Three site champions participated. Eight major themes were identified as follows: (1) ease of use, (2) perception of VTE risk, (3) harms of thromboprophylaxis, (4) overestimation of calculator use, (5) confidence in own ability, (6) underestimation of risk by calculator, (7) variability of trust in calculator, and (8) validation to withhold prophylaxis from low-risk patients.
Conclusions While providers found the calculator is easy to use, routine use may be hindered by distrust of its recommendations. Inaccurate perception of VTE and bleeding risk may prevent calculator use.
Design and testing of an intermittent fertilisation method for seeding of maize (
Authors: Pan Rui , Meng Zhijun , Dong Jianjun , Shang Yehua , Mei Hebo , Yan Bingxin , Fu Weiqiang , Gao Nana , Xue Zhong , Zhang Zhaoguo 
Published: January 2022

The fertiliser that is applied between maize (Zea mays L.) plants via furrow application cannot be completely absorbed and used because of the wide planting space, resulting in fertiliser wastage and soil pollution. To address this issue, we proposed an intermittent fertilisation method for single maize plant seeding, and designed a fertilisation device that can control the intermittent timing and duration of fertiliser application. A simple indoor bench test was done to verify the feasibility of the device. A synchronised control model of the seed and fertiliser was also established. Thus, a quantitative precision intermittent fertilisation system for a single maize plant was developed. The technique was integrated and applied in a current mainstream quantitative precision seeder and fertiliser feeder for maize in field trials. The trial results showed that the average centre distance between the seed and the fertiliser was 5–8 cm and the qualification rate was >90%. The effective length of fertilisation was about one-third of plant spacing, and the largest coefficient of variation was 12.37%. In conclusion, the present quantitative precision interval fertilisation system can feed and apply fertiliser to the predetermined fertiliser site of maize plants, realising the ‘one seed and one fertiliser’ seeding and fertilisation mode, which reduced the fertiliser application amount and increased the fertiliser utilisation rate.
Extracellular vimentin is an attachment factor that facilitates SARS-CoV-2 entry into human endothelial cells
Authors: Amraei Razie , Xia Chaoshuang , Olejnik Judith , White Mitchell R. , Napoleon Marc A. , Lotfollahzadeh Saran , Hauser Blake M. , Schmidt Aaron G. , Chitalia Vipul , Mühlberger Elke , Costello Catherine E. , Rahimi Nader 
Published: January 2022

Significance
Human angiotensin-converting enzyme 2 (ACE2) is the most widely known entry receptor for SARS-CoV-2. The possible involvement of other cellular components in viral entry mechanisms remains unknown. Vimentin is expressed in human endothelial cells, binds to SARS-CoV-2-spike, and expedites SARS-CoV-2 entry. Treatment of lung ACE2/A549 carcinoma cells with purified vimentin or coculture of ACE2/A549 cells with HEK-293 cells expressing vimentin increased ACE2-dependent viral entry. CR3022 antibody blocked vimentin interaction with SARS-CoV-2-spike and inhibited SARS-CoV-2 entry. Vimentin could facilitate SARS-CoV-2 infection and contribute to vascular complications associated with COVID-19.
DBI inflation and warped black holes
Authors: Kamenshchik Alexander Y. , Tronconi Alessandro , Venturi Giovanni 
Published: January 2022

Abstract
We study a possible amplification mechanism for the curvature perturbations generated during inflation by a Dirac-Born-Infeld (DBI) inflaton in the presence of a sharp feature in the warp factor. The large growth resulting in the scalar power spectrum is a consequence of the decreasing speed of sound. We obtain analytical approximate expressions for the relevant dynamical quantities both in the slow roll phase and during the transient phase which leads to the amplification. We finally compare our approximations to the exact numerical evolution and give, in such a context, the general rules for building a viable inflationary model leading to, during the subsequent radiation dominated era, an abundant primordial black holes formation.
Decoding motor imagery tasks using ESI and hybrid feature CNN
Authors: Fang Tao , Song Zuoting , Zhan Gege , Zhang Xueze , Mu Wei , Wang Pengchao , Zhang Lihua , Kang Xiaoyang 
Published: January 2022

Abstract

Objective. Brain–computer interface (BCI) based on motor imaging electroencephalogram (MI-EEG) can be useful in a natural interaction system. In this paper, a new framework is proposed to solve the MI-EEG binary classification problem. Approach. Electrophysiological source imaging (ESI) technology is used to solve the influence of volume conduction effect and improve spatial resolution. Continuous wavelet transform and best time of interest (TOI) are combined to extract the optimal discriminant spatial-frequency features. Finally, a convolutional neural network with seven convolution layers is used to classify the features. In addition, we also validated several new data augment methods to solve the problem of small data sets and reduce network over-fitting. Main results. The model achieved an average classification accuracy of 93.2% and 95.4% on the BCI Competition III IVa and high-gamma data sets, which is better than most of the published advanced algorithms. By selecting the best TOI for each subject, the classification accuracy rate increased by about 2%. The effects of four data augment methods on the classification results were also verified. Among them, the noise addition and overlap methods are better than the other two, and the classification accuracy is improved by at least 4%. On the contrary, the rotation and flip data augment methods reduced the classification accuracy. Significance. Decoding MI tasks can benefit from combing the ESI technology and the data augment technology, which is used to solve the problem of low spatial resolution and small samples of EEG signals, respectively. Based on the results, the model proposed has higher accuracy and application potential in the task of MI-EEG binary classification.
Fast and accurate decoding of finger movements from ECoG through Riemannian features and modern machine learning techniques
Authors: Yao Lin , Zhu Bingzhao , Shoaran Mahsa 
Published: January 2022

Abstract

Objective. Accurate decoding of individual finger movements is crucial for advanced prosthetic control. In this work, we introduce the use of Riemannian-space features and temporal dynamics of electrocorticography (ECoG) signal combined with modern machine learning (ML) tools to improve the motor decoding accuracy at the level of individual fingers. Approach. We selected a set of informative biomarkers that correlated with finger movements and evaluated the performance of state-of-the-art ML algorithms on the brain-computer interface (BCI) competition IV dataset (ECoG, three subjects) and a second ECoG dataset with a similar recording paradigm (Stanford, nine subjects). We further explored the temporal concatenation of features to effectively capture the history of ECoG signal, which led to a significant improvement over single-epoch decoding in both classification (p < 0.01) and regression tasks (p < 0.01). Main results. Using feature concatenation and gradient boosted trees (the top-performing model), we achieved a classification accuracy of 77.0% in detecting individual finger movements (six-class task, including rest state), improving over the state-of-the-art conditional random fields by 11.7% on the three BCI competition subjects. In continuous decoding of movement trajectory, our approach resulted in an average Pearson’s correlation coefficient (r) of 0.537 across subjects and fingers, outperforming both the BCI competition winner and the state-of-the-art approach reported on the same dataset (CNN + LSTM). Furthermore, our proposed method features a low time complexity, with only

<

17.2 s required for training and

<

50 ms for inference. This enables about 250× speed-up in training compared to previously reported deep learning method with state-of-the-art performance. Significance. The proposed techniques enable fast, reliable, and high-performance prosthetic control through minimally-invasive cortical signals.
Machine Learning techniques applied to Road Health Status Recognition through Tyre Cavity Noise Analysis
Authors: Schiaffino Gloria , Del Pizzo Lara Ginevra , Silvestri Stefano , Bianco Francesco , Licitra Gaetano , Praticò Filippo Giammaria 
Published: January 2022

Abstract
This paper proposes a system based on Neural Networks (NN), designed for providing an efficient, non-invasive and automated method for monitoring the health status of road pavements by using features derived from Tyre Cavity Noise (TCN) analysis. Indeed, visual inspection remains to date the most common choice for evaluating the condition of road pavements; however, this method is both labor intensive and time consuming. The system presented in this work uses a microphone placed inside the vehicle tyre that measures TCN while travelling normally, and an embedded data acquisition system based on a Raspberry Pi which feeds the NN tools to recognize and classify road deterioration. We also present a preliminary analysis of features based on temporal and spectral characteristics of TCN signals generated by tyre/road interaction and acquired on three different kind of road distresses. The results show good classification capability and, moreover, the sound pressure measured inside the tyre was correlated accelerometric data measured on-board.
Computational simulations and assessment of two approaches for x-ray phase contrast imaging
Authors: Bliznakova Kristina , Bliznakov Zhivko , Dukov Nikolay 
Published: January 2022

Abstract
X-ray phase-contrast imaging is a high-resolution imaging that permits an increase of the perceptibility of the details in three-dimensional objects, such as human tissues compared to conventional absorption imaging. There are different approaches for implementing phase-contrast imaging and their introduction into clinical practice requires advanced computational tools. A long-term goal of our research is the development of computational models of breast phase-contrast imaging. The aim of this study is to develop a software module for implementing grating-based phase-contrast imaging. For this purpose, an existing in-house software application for x-ray imaging with a function to model and simulate propagation-based phase-contrast x-ray images has been extended to include a model of grating-based imaging. To test the new functionality, four computational phantoms reflecting features, which can be screened in the real breast tissue and which differ in their complexity, were designed. Planar x-ray images in absorption, propagation-based and grating-based modes were generated and compared. Results showed improved visual appearance of the simulated objects in images obtained by simulating grating-based imaging setup. The developed subroutine is planned to be experimentally validated at synchrotron facility. The new software functionality will be exploited in studies related to new x-ray imaging techniques for breast screening and diagnosing.
Calculation of depressurization coordinate in underground and offshore gas pipelines
Authors: Kurbatova G I , Klemeshev V A , Filippov V B 
Published: January 2022

Abstract
The paper introduces a method for calculating the depressurization coordinate of an extended ultra-high pressure gas pipeline from the data measurements of pressure and flow rate at the outlet. The method is based on a mathematical model of a non-isothermal steady single-phase gas mixture flow through a pipeline of constant section on the quasi-linearization method. It allows to calculate the depressurization coordinate for extended underground and offshore ultra-high pressure gas pipelines with high accuracy, while considering varying leakage size and location. Examples of solving problems of practical interest are given. The influence of the flow rate and pressure settings error on the coordinate of depressurization calculating error has been demonstrated.
Study on the Influence of Temperature on Ultrasonic Pressure Measurement Technology
Authors: Zhang Yuqing , Ming Tingfeng , LI Jing 
Published: January 2022

Abstract
Ultrasonic pressure measurement is an advanced measurement technology, but it has a great influence on temperature. Aiming at the problem that the pressure of ultrasonic measurement pipeline is affected by temperature, the pipeline is modeled and simulated by finite element method. The ultrasonic transducer is used to transmit and receive sound waves. The time difference of sound waves received by the transducer under different temperatures is simulated to determine the corresponding sound velocity. The data is analyzed and processed to establish the mathematical model of sound velocity and temperature, The influence of temperature on pressure measurement is analyzed, which plays an important role in reducing the pressure error of ultrasonic measurement pipeline.
Research on Intelligent Design of Machine Tool Guide Rail Based on Case-based Reasoning
Authors: Li Fangzhen , Wang Pengjia , Peng Baoying , Yang Qingdong 
Published: January 2022

Abstract
In order to solve the problem of low efficiency of machine tool guide rail design, reduce design cost and shorten design cycle, a guide rail design method based on case-based reasoning is proposed. First, the framework of the intelligent design system for machine tool guide rails is constructed; based on the water injection principle WFT in the communication field, by establishing the rationality index of weight distribution, the Lagrangian function is constructed to optimize the weights, and the convergent water injection distribution algorithm is obtained. Similarity calculation performs case retrieval, and makes corresponding parameterized modifications to similar cases. The research results show that the intelligent design method of the machine tool guide rail can quickly and automatically retrieve similar cases, so as to realize the intelligence and automation of the machine tool guide rail design, speed up the product design process, and improve the design efficiency.
Advanced manufacturing technology and modeling optimization based on moldflow analysis ——Take the design process of “Snowflake Bracket” as an example
Authors: Yang Weimin , Shi Siqi , Zhan Jin 
Published: January 2022

Abstract
In the past product creative design process, the design mainly relied on the designer’s intuition and experience. After the plan is completed, it needs several revisions and adjustments before it can be officially put into production. After discovering the problem, it is necessary not only to re-adjust the process parameters, but also to modify the plastic products and molds. This design method reduces the development speed of new products. This research proposes an innovative design method that applies moldflow advanced manufacturing technology to the initial shape optimization of product design, which can help us to accurately grasp the initial product design link and ensure that the product meets the plan expectations and aesthetic needs. Shorten the overall product development process and have good application prospects.
Split Structure Design of Magnetic Liquid Sealing Device for High Power Motor
Authors: Xing Feifei , Ruican Hao , Ji Jun 
Published: January 2022

Abstract
According to the special working conditions of high-power motors, this paper designs a split magnetic liquid sealing device. The material is 316 austenitic stainless steel, which has good mechanical properties. In addition, the material contains Mo element, which has good corrosion resistance and high temperature resistance. It is suitable for use under harsh conditions and meets the special use conditions of high-power motors. In addition, the end cover also adopts a split structure. The design of the pole shoe also adopts a split structure, and a connecting hole is opened on it for the two parts of the split structure to be connected with hexagon socket head screws. The pole piece is a key component in the magnetic liquid sealing device. Its function is to form a magnetic circuit. The material is required to have high permeability and low coercivity.