bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved YOLOv8 for B-scan image flaw detection of the heavy-haul railway
Authors: Yu Chengshui , Liu Yue , Cao Yuan , Sun Yongkui , Su Shuai , Yang Weifeng , Wang Wenkun 
Published: April 2024

Abstract
With the high speed and heavy duty of railway transportation, internal flaw detection of railway rails has become a hot issue. Existing rail flaw detection systems have problems of low detection accuracy and occasional missed flaw detection. In this paper, a high-precision flaw detection based on data augmentation and YOLOv8 improvement is proposed. Firstly, three data augmentation algorithms based on the characteristics of B-scan images are designed to enrich the dataset of rail flaws. Then, the small target detection layer and the cross-layer connectivity module are added to capture more information for small targets. Finally, the introduction of dynamic weights to coordinate attention can adjust the attentional weights and capture long-range information. The experimental results show that the mAP50 of the model after data enhancement and algorithm improvement is 97.9%, which is improved by 4.4% from the baseline model, and the frame per second is 64.52. The proposed method effectively detects many typical flaws, including the railhead flaw, rail jaw flaw, screw hole crack, and bottom flaw, which can provide technology supports for on-site maintenance staff.
Do we really need machine learning interatomic potentials for modeling amorphous metal oxides? Case study on amorphous alumina by recycling an existing ab initio database
Authors: Gramatte Simon , Turlo Vladyslav , Politano Olivier 
Published: April 2024

Abstract
In this study, we critically evaluate the performance of various interatomic potentials/force fields against a benchmark ab initio database for bulk amorphous alumina. The interatomic potentials tested in this work include all major fixed charge and variable charge models developed to date for alumina. Additionally, we introduce a novel machine learning interatomic potential constructed using the NequIP framework based on graph neural networks. Our findings reveal that the fixed-charge potential developed by Matsui and coworkers offers the most optimal balance between computational efficiency and agreement with ab initio data for stoichiometric alumina. Such balance cannot be provided by machine learning potentials when comparing performance with Matsui potential on the same computing infrastructure using a single Graphical Processing Unit. For non-stoichiometric alumina, the variable charge potentials, in particular ReaxFF, exhibit an impressive concordance with density functional theory calculations. However, our NequIP potentials trained on a small fraction of the ab initio database easily surpass ReaxFF in terms of both accuracy and computational performance. This is achieved without large overhead in terms of potential fitting and fine-tuning, often associated with the classical potential development process as well as training of standard deep neural network potentials, thus advocating for the use of data-efficient machine learning potentials like NequIP for complex cases of non-stoichiometric amorphous oxides.
Spectrality of a class of infinite convolutions on
R
*
Authors: Wu Sha , Xiao Yingqing 
Published: April 2024

Abstract
Given an integer

m
⩾
1

. Let

Σ

(
m
)

=
{
1
,
2
,
…
,
m

}

N

be a symbolic space, and let

{
(

b

k

,

D

k

)

}

k
=
1

m

:=
{
(

b

k

,
{
0
,
1
,
…
,

p

k

−
1
}

t

k

)

}

k
=
1

m

be a finite sequence pairs, where integers

|

b

k

|

,

p

k

⩾
2

,

|

t

k

|

⩾
1

and

p

k

,

t

1

,

t

2

,
…
,

t

m

are pairwise coprime integers for all

1
⩽
k
⩽
m

. In this paper, we show that for any infinite word

σ
=

(

σ

n

)

n
=
1

∞

∈

Σ

(
m
)

, the infinite convolution

μ

σ

=

δ

b

σ

1

−
1

D

σ

1

∗

δ

(

b

σ

1

b

σ

2

)

−
1

D

σ

2

∗

δ

(

b

σ

1

b

σ

2

b

σ

3

)

−
1

D

σ

3

∗
⋯

is a spectral measure if and only if

p

σ
n

∣

b

σ
n

for all

n
⩾
2

and

σ
∉

⋃

l
=
1

∞

∏

l

, where

∏

l

=
{

i

1

i

2

⋯

i

l

j

∞

∈

Σ

(
m
)

:

i

l

≠
j
,

|

b

j

|

=

p

j

,

|

t

j

|

≠
1
}

.
Weakened vortex stretching effect in three scale hierarchy for the 3D Euler equations
Authors: Jeong In-Jee , Na Jungkyoung , Yoneda Tsuyoshi 
Published: April 2024

Abstract
We consider the three-dimensional incompressible Euler equations under the following three scale hierarchical situation: large-scale vortex stretching the middle-scale, and at the same time, the middle-scale stretching the small-scale. In this situation, we show that, the stretching effect of this middle-scale flow is weakened by the large-scale. In other words, the vortices being stretched could have the corresponding stress tensor being weakened.
Dynamic analysis of major public health emergency transmission considering the dual-layer coupling of community–resident complex networks
Authors: Yang 杨 Peng 鹏 , Fan 范 Ruguo 如国 , Wang 王 Yibo 奕博 , Zhang 张 Yingqing 应青 
Published: April 2024

Abstract
We construct a dual-layer coupled complex network of communities and residents to represent the interconnected risk transmission network between communities and the disease transmission network among residents. It characterizes the process of infectious disease transmission among residents between communities through the SE2IHR model considering two types of infectors. By depicting a more fine-grained social structure and combining further simulation experiments, the study validates the crucial role of various prevention and control measures implemented by communities as primary executors in controlling the epidemic. Research shows that the geographical boundaries of communities and the social interaction patterns of residents have a significant impact on the spread of the epidemic, where early detection, isolation and treatment strategies at community level are essential for controlling the spread of the epidemic. In addition, the study explores the collaborative governance model and institutional advantages of communities and residents in epidemic prevention and control.
One memristor–one electrolyte-gated transistor-based high energy-efficient dropout neuronal units
Authors: Li 李 Yalin 亚霖 , Shi 时 Kailu 凯璐 , Zhu 朱 Yixin 一新 , Fang 方 Xiao 晓 , Cui 崔 Hangyuan 航源 , Wan 万 Qing 青 , Wan 万 Changjin 昌锦 
Published: April 2024

Abstract
Artificial neural networks (ANN) have been extensively researched due to their significant energy-saving benefits. Hardware implementations of ANN with dropout function would be able to avoid the overfitting problem. This letter reports a dropout neuronal unit (1R1T-DNU) based on one memristor–one electrolyte-gated transistor with an ultralow energy consumption of 25 pJ/spike. A dropout neural network is constructed based on such a device and has been verified by MNIST dataset, demonstrating high recognition accuracies (> 90%) within a large range of dropout probabilities up to 40%. The running time can be reduced by increasing dropout probability without a significant loss in accuracy. Our results indicate the great potential of introducing such 1R1T-DNUs in full-hardware neural networks to enhance energy efficiency and to solve the overfitting problem.
The
tetraquark system in a chiral quark model*
Authors: Yang 杨 Gang 刚 , Ping 平 Jialun 加伦 , Segovia Jorge 
Published: April 2024

Abstract
The S-wave

tetraquarks, with spin-parities

,

, and

, in both isoscalar and isovector sectors, are systematically studied using a chiral quark model. The meson-meson, diquark-antidiquark, and K-type arrangements of quarks and all possible color wave functions are comprehensively considered. The four-body system is solved using the Gaussian expansion method, a highly efficient computational approach. Additonally, a complex-scaling formulation of the problem is established to disentangle bound, resonance, and scattering states. This theoretical framework has already been successfully applied in various tetra- and penta-quark systems. For the complete coupled channel and within the complex-range formulation, several narrow resonances of

and

systems are obtained, in each allowed

-channel, within the energy regions of

GeV and

GeV, respectively. The predicted exotic states, which indicate a richer color structure when going towards multiquark systems beyond mesons and baryons, are expected to be confirmed in future high-energy particle and nuclear experiments.
Effects of magnetic helicity on 3D equilibria and self-organized states in KTX reversed field pinch
Authors: Liu Ke , Yu Guodong , Huang Yuhua , Mao Wenzhe , Xie Yidong , Nie Xianyi , Li Hong , Lan Tao , Xie Jinlin , Ding Weixing , Liu Wandong , Zhuang Ge , Zhu Caoxiang 
Published: April 2024

Abstract
The reversed field pinch (RFP) is a toroidal magnetic configuration in which plasmas can spontaneously transform into different self-organized states. Among various states, the ‘quasi-single-helical’ (QSH) state has a dominant component for the magnetic field and significantly improves confinement. Many theoretical and experimental efforts have investigated the transitions among different states. This paper employs the multi-region relaxed magnetohydrodynamic model to study the properties of QSH and other states. The stepped-pressure equilibrium code (SPEC) is used to compute MHD equilibria for the Keda Torus eXperiment (KTX). The toroidal volume of KTX is partitioned into two subvolumes by an internal transport barrier. The geometry of this barrier is adjusted to achieve force balance across the interface, ensuring that the plasma in each subvolume is force-free and that magnetic helicity is conserved. By varying the parameters, we generate distinct self-organized states in KTX. Our findings highlight the crucial role of magnetic helicity in shaping these states. In states with low magnetic helicity in both subvolumes, the plasma exhibits axisymmetric behavior. With increasing core helicity, the plasma gradually transforms from an axisymmetric state to a double-axis helical state and finally to a single-helical-axis state. Elevated core magnetic helicity leads to a more pronounced dominant mode of the boundary magnetic field and a reduced core magnetic shear. This is consistent with previous experimental and numerical results in other RFP devices. We find a linear relationship between the plasma current and helicity in different self-organized states. Our findings suggest that KTX may enter the QSH state when the toroidal current reaches 0.72 MA. This study demonstrates that the stellarator equilibrium code SPEC unveils crucial RFP equilibrium properties, rendering it applicable to a broad range of RFP devices and other toroidal configurations.
Biological, physical and morphological factors for the programming of a novel microbial hygromorphic material
Authors: Birch Emily , Bridgens Ben , Zhang Meng , Dade-Robertson Martyn 
Published: April 2024

Abstract
The urgency for energy efficient, responsive architectures has propelled smart material development to the forefront of scientific and architectural research. This paper explores biological, physical, and morphological factors influencing the programming of a novel microbial-based smart hybrid material which is responsive to changes in environmental humidity. Hygromorphs respond passively, without energy input, by expanding in high humidity and contracting in low humidity. Bacillus subtilis develops environmentally robust, hygromorphic spores which may be harnessed within a bilayer to generate a deflection response with potential for programmability. The bacterial spore-based hygromorph biocomposites (HBCs) were developed and aggregated to enable them to open and close apertures and demonstrate programmable responses to changes in environmental humidity. This study spans many fields including microbiology, materials science, design, fabrication and architectural technology, working at multiple scales from single cells to ‘bench-top’ prototype.
Exploration of biological factors at cellular and ultracellular levels enabled optimisation of growth and sporulation conditions to biologically preprogramme optimum spore hygromorphic response and yield. Material explorations revealed physical factors influencing biomechanics, preprogramming shape and response complexity through fabrication and inert substrate interactions, to produce a palette of HBCs. Morphological aggregation was designed to harness and scale-up the HBC palette into programmable humidity responsive aperture openings. This culminated in pilot performance testing of a humidity-responsive ventilation panel fabricated with aggregated Bacillus HBCs as a bench-top prototype and suggests potential for this novel biotechnology to be further developed.
Interaction of barn owl leading edge serrations with freestream turbulence
Authors: Midmer Alden , Brücker Christoph , Weger Matthias , Wagner Hermann , Bleckmann Horst 
Published: April 2024

Abstract
The silent flight of barn owls is associated with wing and feather specialisations. Three special features are known: a serrated leading edge that is formed by free-standing barb tips which appears as a comb-like structure, a soft dorsal surface, and a fringed trailing edge. We used a model of the leading edge comb with 3D-curved serrations that was designed based on 3D micro-scans of rows of barbs from selected barn-owl feathers. The interaction of the flow with the serrations was measured with Particle-Image-Velocimetry in a flow channel at uniform steady inflow and was compared to the situation of inflow with freestream turbulence, generated from the turbulent wake of a cylinder placed upstream. In steady uniform flow, the serrations caused regular velocity streaks and a flow turning effect. When vortices of different size impacted the serrations, the serrations reduced the flow fluctuations downstream in each case, exemplified by a decreased root-mean-square value of the fluctuations in the wake of the serrations. This attenuation effect was stronger for the spanwise velocity component, leading to an overall flow homogenization. Our findings suggest that the serrations of the barn owl provide a passive flow control leading to reduced leading-edge noise when flying in turbulent environments.
Modelling and experimental analysis of high-temperature effect on rubberized concrete
Authors: Covatariu D , Alexa-Stratulat M S , Covatariu G 
Published: April 2024

Abstract
The study presents results concerning the comparison of modelling and experimental work on rubberized concrete exposed to high temperatures. Crumb rubber was used in different concentrations to replace coarse aggregate. Experiments were made on flat-cylindrical specimens extracted from larger samples in order to be analysed. Simulations have been employed to calibrate measurements and to further analyse the specimens in an effort to prove their worth as a viable mechanism in studying larger-scale phenomena.
Earthquake behavior of flat slab structures, particularities and opportunities for use in the building stock of the Chisinau municipality
Authors: Sîli A A 
Published: April 2024

Abstract
The Republic of Moldova is characteristic for active seismic phenomena and there is always a direct danger of strong earthquakes. The building stock of the country has a complex character, this aspect is manifested in the municipality of Chisinau, where we have different buildings in terms of materials used, structural systems and height regime. New trends in construction are focused on buildings with a load-bearing frame structural system and a frame with a flat slab structure. The usual design practice is characteristic for the implementation of beam-column systems, where the plates are supported by the beams and the beams are supported by the columns. Nowadays, for the residential buildings design, a more elegant and ergonomic floor system is used - the flat slab system. Therefore, the slabs are subjected to increased loads, which requires special attention in the design and implementation of these types of structures.
Evaluation Methods for Traditional Houses in Dobrogea
Authors: Şeitan T , Andrieş D I , Grămescu A M 
Published: April 2024

Abstract
Assessing the technical condition of earthen constructions is an extremely difficult task due to the fact that the materials, methods and techniques used in construction have been replaced by new materials and installation procedures. Although they have a fairly large share in the existing housing stock, earthen constructions have not benefited from the same interest in the field of construction. This paper proposes a review of the current assessment possibilities applicable to earthen constructions in relation to the current level of knowledge on a local and international level.
Predicting multi-span bridge maximum deflection: Numerical simulation and validation
Authors: Brinissat M , Ray R P , Kuti R 
Published: April 2024

Abstract
Deflection is one of the main parameters often required to reflect and monitor the overall health state of bridge structures. Several approaches have been developed to monitor deflection accurately and economically. This research proposes a theoretical method to estimate the maximum deflection of the longest section of a seven-span continuous bridge using stress data collected through strain gauges. Firstly, initial data were collected from field tests under various controlled loadings to obtain the maximum deflections and stresses. Then, the stress-deflection regression equations are derived to reconstruct deflection from estimated gauges. Finally, the maximum deflection values are compared with analytical results using finite element simulations to verify the method’s effectiveness.
The influence of soil specimens shape and dimensions on consolidation parameters used in foundation settlement prediction
Authors: Dascălu A V , Lungu I , Aniculăesi M , Bejan F 
Published: April 2024

Abstract
The theory of elasticity is used in geotechnical engineering for the calculation of foundation settlement. The equation used in the evaluation of consolidation settlement uses the soil compressibility parameters which usually are determined on cylindrical soil specimens with ϕ 71.4 mm. Laboratory tests performed on soil specimens showed that the parameters that are used in foundation settlement analysis are influenced by the dimensions of the tested soil specimens and the shape of that specimen. The paper presents the influence of specimen size, shape and method used for the coefficient of consolidation evaluation on the final value of the foundation settlement. The analysis was performed using the Settle3 software from Rocsience, considering the case of an elastic foundation flexible square foundation (1.5 m × 1.5 m) which transmits to the ground a pressure of 100 kPa.
The influence of the geometric characteristics on the behavior of braces with restrained buckling - case study of perforated steel core.
Authors: Mocanu Basalic C P , Luca S G , Lungu I , Mihai P 
Published: April 2024

Abstract
Buckling restrained braces are elements that equip the building with additional capacity for resistance and stability when subjected to earthquakes. As an answer to the problem of the possible loss of stability of the buckling-preventing component, the “perforated-core buckling restrained braces” (PCBRB) is a concept that involves the introduction of gaps, in the core of the bracing, to control the plasticizing mechanism of the dissipative element. The research addresses the behavior of PCBRB groups where all the elements belonging to the same group have the same area and length of the section considered active dissipative. A numerical analysis environment was developed that simulates the support conditions and material behavior. Based on the results of the numerical analyses, the influence of the geometry (b/t ratio) of the section of the dissipative zone on the behavior and the mechanism of stress strain distribution in the bracing core. It can be noticed the development of over-resistance to the compressive stress and non-uniform distribution of stresses on the surface of the elements whose b/t ratio exceeds the value of 5.5; for the elements whose b/t ratio has a value lower than 1.75 local instability problems in the dissipative zone occurred.
Demolition of a reinforced concrete overpass. Case study
Authors: Boacă G , Scutaru M C , Iriciuc C S , Gimiga G R , Dima D N 
Published: April 2024

Abstract
Bridges are built to fulfil different roles depending on the needs of the site. One of the most important role is to provide easy and non-life-threating access to different areas of community interest. Over the period of their operation, structures suffer various degradations whose extension may endanger the integrity of the construction, or the changing needs of the users. This raises the problem of finding the most efficient methods of removing the structure from use and returning the land to other uses adapted to the period needs. The structure to which we have turned our attention in this article is located in Bucharest. It is represented by an overpass built in a frame solution with inclined pillars, having the shape of the letter ”V”. The construction material consists mainly of monolithic cast reinforced concrete. The present article presents a modern methodology for the demolition of the reinforced concrete overpass in discussion, through the progressive dismantling of the component construction elements. This method has many advantages, particularly in terms of the possibility of recycling the construction materials used and in terms of minimising traffic congestion on the railway.
The impact of the embankment and the recreational lake on capturing front with drilling wells
Authors: Marcoie N , Toacă D , Toma D , Boboc V , Hrăniciuc T A , Mitroi R 
Published: April 2024

Abstract
This paper presents the influence on the levels from the well caption front Gherăeşti-Bacău, located on the right side of the Bistrița River, through the construction, on the right shore, of a 2.25 km long perimetral embankment, and a recreational lake with a surface of 3.18 hectares and average depth of 5.5 m (Figure 1). Through numerical modelling, using the modelling software of Visual Modflow aquifer, the influence on the hydrostatic level from drilled wells was determined, as well as the influence on the phreatic flow through the making of the recreational lake, which captures a part of the underground water. The use of the mathematical model allows the determination of the optimal parameters for an extraction from the aquifer known through classical methods. To achieve the mathematical model the method of filtration resistances was used, which is applied in the case of a sudden curvature of the streamlines (in the proximity of the imperfect permeable/impervious borders: channels, drains, well systems, screens), hence they are applied during pressure/level drops. This method allows the following equalizations: the imperfect wells can be considered as perfect; the lines of perfect/imperfect wells can be considered as perfect trenches (channels) with a flow equal to the sum of all wells; a stratified aquifer (up to 3 layers) can be equivaled with a homogenous one. Aspects regarding the flow were taken into consideration: with a free level or under pressure, the dimensioning of the model, the initial conditions of the aquifer layer, the lithostratigraphic characteristics, homogeneity, anisotropy, the transfer mechanisms in the domain’s interior, the studied hydrogeological structure was schematized, having done a monolayer model. The calibration of the model consists of adjusting, in reasonable conditions, of the domain data (the permeabilities), boundary conditions, so that through the running of the model and obtaining the corresponding piezometric lines and the obtained data will overlap the levels of the existing drillings.