bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of microbiota–testis interactions on the reproductive health of male ruminants: A review
Authors: Pan Cheng , Zhaxi Yangzong , Li Haiyan , Guan Feng , Pan Junru , Wa Da , Song Tianzeng , Zhao Wangsheng
Published: August 2024

Ruminants are one of the world's economically important species, and their reproductive health is critical to the economic development of the livestock industry. In recent years, research on the relationship between microbiota and reproductive health has received much attention. Microbiota disruption affects the developmental health of the testes and epididymis, the male reproductive organs of the host, which in turn is related to sperm quality. Maintaining a stable microbiota protects the host from pathogens and increases breeding performance, which in turn promotes the economic development of animal husbandry. In addition, the effects and mechanisms of microbiota on reproduction were further explored. These findings support new approaches to improving and managing reproductive health in ruminants through the microbiota and facilitate further systematic exploration of microbiota‐mediated reproductive impacts.
A path to professional capability: The Career Start Programme in Bulgaria as a strategy to youth development
Authors: Yakova Lilia , Politov Alexander , Gerganov Alexander
Published: August 2024

This article looks into the Career Start Programme in Bulgaria through the prism of Sen's capability approach, and more particularly—the application of the approach to career guidance, employment programmes and youth labour market activation [Correction added on 15 August 2024, after first online publication: The full name of the programme in the previous sentence has been defined in this version.]. It analyses the programme's effects on its beneficiaries in enhancing their capability for work and capability for knowledge. Through qualitative and quantitative data analysis, we examine: (1) how the programme affects the participants' meaningful choices to aspire for and get a desired job and to develop sustainable career paths, and (2) how the programme influences the participants' capability for learning and skill acquisition. We find that, as a whole, the programme has positive influences on the larger part of its beneficiaries, as it equips them with the necessary capabilities to develop their future careers. We, however, observe certain issues with the programme calling for adjustments, so that young participants are better empowered to participate in the design of youth initiatives and formulate NEET‐related and youth employment policies that will be more conducive to their career paths in the future and to their aspirations for jobs they value.
Making a Subjective Atlas of Palestine: On participative design and situated mapping
Authors: de Vet Annelys
Published: August 2024

This paper offers a reflection on the design ethos and process behind the production of the Subjective Atlas of Palestine – the third of 15 Subjective Atlases that I have facilitated over the past 20 years as a graphic designer and initiator. They are bottom‐up cartographic publications that map countries, regions, or cities through the perspectives of local inhabitants, emerging from participative production processes where communities map their environment through myriad visualisations, such as graphs, maps, drawings, and photography. Unlike conventional mapping, this methodology for counter‐mapping fosters a place‐based understanding grounded in lived experiences, and promotes plural representation. How can designers facilitate collective imagination as a practice for counter‐mapping and reterritorialisation? In solidarity with the Palestinian struggle for a life of dignity and justice, I reiterate the creation and dissemination of the Subjective Atlas of Palestine as a timely reminder of cartography's implication in generating and sustaining a violent geopolitical order in Palestine–Israel.
Implementing pathogen reduction technology while discontinuing blood donor deferral criteria for sexual risk behaviors: A simulation study
Authors: Domingue Marie‐Pier , O'Brien Sheila F. , Grégoire Yves , Lanteri Marion C. , Stramer Susan L. , Camirand Lemyre Félix , Lewin Antoine
Published: August 2024

Background

Combining pathogen reduction technology (PRT) with blood screening may alleviate concerns over the risk of transfusion‐transmitted infections (TTI) and support changes in blood donor selection to potentially increase blood availability. This study aimed to estimate the residual risk of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) transfusion‐transmission in Canada after implementing PRT, while eliminating deferrals for sexual risk behaviors.

Study Design and Methods

A probabilistic approach that combined Bayesian networks with Monte Carlo simulations was used to estimate the risk of transfusing HIV‐, HBV‐, or HCV‐contaminated blood components. Different scenarios were considered to compare the current residual risk after PRT implementation, with and without donor deferral criteria for sexual risk behaviors. Donor profiles and blood component outcomes were simulated based on a literature review including the prevalence and incidence of HIV, HBV, and HCV in the Canadian blood donor population; the use of current blood screening assays; and HIV, HBV, and HCV blood donor viral loads.

Results

In the universal PRT scenario (i.e., with PRT/without deferral criteria), the estimated risks of HIV, HBV, and HCV transmission were significantly lower than those in the currently observed scenario (i.e., without PRT/with deferral criteria).

Conclusions

This risk model suggests that PRT for platelets and plasma (and eventually for RBCs when available) significantly reduces the residual risks of HIV, HBV and HCV transfusion‐transmission and could enable the removal of blood donor deferral criteria for sexual risk behaviors.
Comments and illustrations of the WFUMB CEUS liver guidelines: rare benign hematological focal liver lesions (hepatic extramedullary hematopoiesis, Hemophagocytic lymphohistiocytosis, reactive lymphoid hyperplasia)
Authors: Alhyari Amjad , Safai Zadeh Ehsan , Algíbez Ana Martín , Berzigotti Annalisa , Görg Christian , Trenker Corinna , Jenssen Christian , Lim Adrian , Möller Kathleen , Dong Yi , Cui Xin Wu , Wang Wen-Ping , Dietrich Christoph Frank
Published: August 2024

The manifestation of benign hematological infiltration in the liver is a challenge due to their rare occurrence and therefore, limited awareness and the general need for biopsy and histological confirmation. Owing to the rarity of these lesions, there are limited data concerning their appearance on ultrasound and, specifically, contrast-enhanced ultrasound. In a series of papers, we have compiled the US and CEUS characteristics of rare FLL, where there are few reports and images available, in order to build up a library of these cases. This paper describes the US and CEUS features of benign hematological FLL which include hepatic extramedullary hematopoiesis (EMH), hemophagocytic lymphohistiocytosis (HLH) and reactive lymphoid hyperplasia (RLH). Although these lesions occur rarely in the liver, their correct identification is imperative for appropriate patient`s management.
New horizons in the holographic conformal phase transition
Authors: Eröncel Cem , Hubisz Jay , Lee Seung J. , Rigo Gabriele , Sambasivam Bharath
Published: August 2024

We describe 5D dynamical cosmological solutions of the stabilized holographic dilaton and their role in completion of the conformal phase transition. This analysis corresponds, via the AdS/CFT dictionary, to a study of out-of-equilibrium dynamics where trajectories of the dilaton do not depend solely on thermodynamic quantities in the early universe, but have sensitivity also to initial conditions. Unlike the well-studied thermal transition, which requires quantum tunneling of an infrared brane through the surface of an AdS-Schwarzschild horizon, our approach instead invokes an early epoch in which the cosmology is fully 5-dimensional, with highly relativistic brane motion and with Rindler horizons obscuring the infrared brane at early times. In this context, we demonstrate the existence of a large class of natural initial conditions that seed trajectories where the brane simply passes through the Rindler horizon and into the basin of attraction of the stabilized dilaton potential. This corresponds to successful completion of the phase transition without sacrificing perturbativity of the 5D theory.
A thermodynamic study of $${\textbf {(2+1)}}$$-dimensional analytic charged hairy black holes with Born–Infeld electrodynamics
Authors: Sardeshpande Shravani , Daripa Ayan
Published: August 2024

This work presents analytical black hole solutions for a coupled Einstein–Born–Infeld–Scalar gravity system in AdS spacetime with two different non-minimal coupling functions f(z). For both solutions, we establish the regularity of the scalar field and curvature scalars outside the horizon. For one of the considered coupling cases, thermodynamic analysis in the canonical ensemble reveals stability across all temperatures, while the other case exhibits the Hawking/Page phase transition between the stable large phase of the black hole and thermal-AdS. We investigate the effect of the scalar hair parameter and black hole charge on the phase transition temperature and observe that the critical values of the scalar hair and the charge parameters constrain the feasibility of Hawking/Page phase transition.
Optical properties of a quantum dot confined in inverse square root truncated exponential potential under varied conditions of temperature, hydrostatic pressure, and electric/magnetic fields
Authors: Bayrak Kübra , Kaya Deniz , Bayrak Orhan
Published: August 2024

In this study, we comprehensively investigate the effects of temperature, hydrostatic pressure, linear electric, and uniform magnetic fields on the electronic and optical properties of a quantum dot confined by an inverse square root truncated exponential potential. The bound state energy eigenvalues and corresponding normalized wave functions are calculated through the numerical solution of the Schrödinger equation using the Numerov method. We formulate the effective potential, which depicts the interaction of an electron with semiconductor atoms, as a function of external parameters, including temperature, hydrostatic pressure, and electric/magnetic fields. We elucidate how variations in the effective potential, induced by changes in these external parameters, affect electronic and optical observables.
A Generalized Attention Mechanism to Enhance the Accuracy Performance of Neural Networks
Authors: Jiang Pengcheng , Neri Ferrante , Xue Yu , Maulik Ujjwal
Published: August 2024

In many modern machine learning (ML) models, attention mechanisms (AMs) play a crucial role in processing data and identifying significant parts of the inputs, whether these are text or images. This selective focus enables subsequent stages of the model to achieve improved classification performance. Traditionally, AMs are applied as a preprocessing substructure before a neural network, such as in encoder/decoder architectures. In this paper, we extend the application of AMs to intermediate stages of data propagation within ML models. Specifically, we propose a generalized attention mechanism (GAM), which can be integrated before each layer of a neural network for classification tasks. The proposed GAM allows for at each layer/step of the ML architecture identification of the most relevant sections of the intermediate results. Our experimental results demonstrate that incorporating the proposed GAM into various ML models consistently enhances the accuracy of these models. This improvement is achieved with only a marginal increase in the number of parameters, which does not significantly affect the training time.
Research on the Influence of Progressive Strength Training Based on Deep Learning on Athletes’ Upper Limbs and Circumference
Authors: Ding Zenghui , Hu Weitao
Published: August 2024

At present, progressive strength training in sports training is mainly based on free strength training equipment and combination equipment, and the load intensity depends on the events, seasons and individual conditions of athletes. High-quality training is the key to improving sports performance and training efficiency, and a better grasp of movement rhythm can effectively improve maximum strength. This paper studies the influence of progressive strength training based on deep learning (DL) on athletes’ upper limbs and circumference. Making full use of the existing 2D pose estimation is mature, and applying it to athletes’ 3D pose estimation can effectively improve the accuracy of athletes’ 3D pose estimation, the last layer outputs 3D attitude prediction. The results show that the circumference of left arm in group A, group B and common movement rhythm is also significantly different from those before training ([Formula: see text]), with the increase in the values of 3.36%, 6.43% and 2.01%, respectively. It can be seen that after eight weeks of maximum strength of bench press, the three movement rhythm groups also have a significant impact on the arm circumference of the subjects. In this paper, the classification error of 3DPoseNet network is reduced by at least 6.38% on average, which shows the effectiveness of this method.
Rational singularities and q-birational morphisms
Authors: Kim Donghyeon
Published: August 2024

In this paper, we generalize the notion of rational singularities for any reflexive sheaf of rank [Formula: see text], link our notion of rational singularities with the notion of rational singularities in, [S. Kovacs, Irrational centers, Pure Appl. Math. Q. 7(4) (2011) 1495–1515], and prove generalizations of standard facts about rational singularities. Moreover, by using a definition of non-rational locus, we introduce the notion of [Formula: see text] as a dual notion of well-known Serre’s notion of [Formula: see text], and prove a theorem about [Formula: see text]-birational morphisms.
Cluster lag synchronization in fractional-order community networks with nondelay and delay coupling
Authors: Wu Congling , Wu Zhaoyan
Published: August 2024

Lag synchronization is a special synchronization manner and has wide applications. For community network, in view of the differences among communities, the synchronization lags in different communities may be nonidentical. This paper investigates the cluster lag synchronization in fractional-order community networks with nondelay and delay coupling. The node dynamics in different communities are nonidentical and even have nonidentical dimensions. Based on the Lyapunov stability theory, effective feedback controllers are designed for achieving cluster lag synchronization and several synchronization criteria are derived. Finally, numerical simulations are provided to demonstrate the effectiveness of the theoretical results.
X-Convexity and Quasi-X-Convex Functions with Applications
Authors: Ali Musavvir , Akhter Ehtesham
Published: August 2024

In this paper, we define [Formula: see text]-convex and quasi-[Formula: see text]-convex functions. This class of real functions is the generalization of a family of convex functions. Additionally, we provide a thorough analysis of the core characteristics of these functions in this paper, along with numerous examples that help to illustrate the ideas. Furthermore, quasi-[Formula: see text]-convex, semistrictly quasi-[Formula: see text]-convex, and strictly quasi-[Formula: see text]-convex functions are used to study and show its applications on optimization problems.
A pile-up correction algorithm for STCF ECAL readout electronics
Authors: Yu Hanlin , Shen Zhongtao , Long Yue , Zhang Chengjun , Zhang Yunlong , Jia Zekun , Song Yong , Liu Shubin
Published: August 2024

The Super Tau-Charm Facility (STCF) is a significant initiative for accelerator-based particle physics in China. Electromagnetic Calorimeter (ECAL) is one of the important detectors of STCF, which is tasked with the accurate measurement of photons. STCF ECAL employs pure Cesium iodide (pCsI) as its scintillation crystal and uses a large-area avalanche photodiode (APD) as a photoelectric conversion device. High luminosity of STCF results in significant background levels, leading to pileups challenging conventional signal processing. In this paper, a pile-up correction algorithm called “pipeline optimal filtering” is proposed, and a background simulation platform is built to verify the measurement effect of the algorithm on energy and time.
Symplectic representation of the Ginzburg–Landau theory
Authors: Reis E. A. , Petronilo G. X. A. , Amorim R. G. G. , Belich H. , Khanna F. C. , Santana A. E.
Published: August 2024

In this work, the Ginzburg–Landau theory is represented on a symplectic manifold with a phase space content. The order parameter is defined by a quasi-probability amplitude, which gives rise to a quasi-probability distribution function, i.e. a Wigner-type function. The starting point is the thermal group representation of Euclidean symmetries and gauge symmetry. Well-known basic results on the behavior of a superconductor are re-derived, providing the consistency of representation. The critical superconducting current density is determined and its usual behavior is inferred. The negativity factor associated with the quasi-distribution function is analyzed, providing information about the nonclassicality nature of the superconductor state in the region closest to the edge of the superconducting material.
Scalar and tensor mesons in dd̄, ss̄ and gg→f0, f2
Authors: Sarantsev A. V. , Klempt E.
Published: August 2024

LHCb data on [Formula: see text], [Formula: see text] and [Formula: see text] are fitted in a coupled-channel analysis jointly with data on radiative [Formula: see text] decays, [Formula: see text] elastic scattering and further data sets. Branching ratios for [Formula: see text] are determined and compared to those from radiative [Formula: see text] decays. Above 1500[Formula: see text]MeV, only little intensity is observed in [Formula: see text] decays. In radiative [Formula: see text] decays, the intensities are strong and peak at 1865[Formula: see text]MeV in the scalar wave and at 2210[Formula: see text]MeV in the tensor wave. This pattern is interpreted as further support for the glueball interpretation of [Formula: see text] and of [Formula: see text].
Design of Higher-Dimensional Switching Chaos Generators by Constructing a Closed Hyper-Polyhedron
Authors: Sun Changchun
Published: August 2024

A novel and unified design approach on higher-dimensional switching chaos generators is derived in this paper. The whole n-dimensional linear space is divided into two parts by a closed hyper-polyhedron. Two higher-dimensional linear systems with the simplest structures as switching chaos generators are designed successfully to generate chaos. State matrix of the first linear system is Hurwitz stable. State matrix of the second linear system is not Hurwitz stable. Chaotic dynamical behaviors take place due to switching two systems. The switching trajectories go through the boundary of the closed hyper-polyhedron endlessly. Moreover, the size of the hyper-polyhedron can determine and control the amplitude of the chaotic signals. Specific numerical examples on four-dimensional, five-dimensional and six-dimensional switching chaos generators are employed, respectively, to illustrate the effectiveness of the novel and advanced approach presented in this paper. The proposed approach can also be applied to designing other switching chaos generators with the higher dimension beyond six.
An Empirical Study of Fault Localization on Novice Programs and Addressing the Tie Problem
Authors: Liu Yuxing , Zhong Jiaxin , Hei Qihua , Zhou Xuchuan , Xiao Jingzhong
Published: August 2024

Programming education is becoming increasingly popular in universities. However, due to a lack of debugging experience, novices often encounter numerous difficulties in the programming process. Automatic fault localization techniques have emerged as a promising solution to address this issue. Among these techniques, Spectrum-Based Fault Localization (SBFL) and Mutation-Based Fault Localization (MBFL) have been widely used in industrial programs. However, there is a significant difference between industrial and novice programs and the performance of these methods on novice programs has not been extensively studied.

To fill this gap, we conducted an empirical study to evaluate the fault localization performance and execution overhead of SBFL and MBFL in a typical novice programming environment. Our study specifically examined how different program characteristics, including code coverage and mutation score, affect the accuracy of these localization methods. Additionally, during the study, we identified the tie problem in both methods and further investigated its impact on fault localization techniques in novice programs.

To remove the impact of the tie problem, we proposed using PageRank scores as weights for the suspiciousness, sorting, and locating faults based on the weighted suspiciousness. The PageRank algorithm is based on statement coverage information and constructs a directed graph. From the directed graph, a transition matrix generates the weight scores (PageRank scores) for each statement.

Our research demonstrates that both SBFL and MBFL are effective for fault localization in novice programs, with MBFL showing significantly better performance in our tests. In TOP-[Formula: see text], MBFL accurately locates 67, 96 and 114 faults, respectively, indicating superior performance. Additionally, calculating weighted suspiciousness significantly alleviates the tie problem.
Enhancing Constraint Acquisition Through Hybrid Learning: An Integration of Passive and Active Learning Strategies
Authors: Balafas Vasileios , Tsouros Dimosthenis C. , Ploskas Nikolaos , Stergiou Kostas
Published: August 2024

Constraint Programming (CP) is a successful methodology for solving combinatorial problems from various domains. Efficiently modeling the problem at hand as a Constraint Satisfaction Problem is a crucial, but difficult task in CP. Toward this, a recent approach that is attracting increasing interest is Constraint Acquisition, i.e., the (semi)automatic learning of constraints through examples of solutions and non-solutions. This paper introduces a hybrid methodology that combines passive and active learning strategies to acquire both global and fixed arity constraints. This hybrid approach leverages the strengths of both techniques to address their individual limitations. Passive learning rapidly learns constraints from example solutions, while active learning refines and contextualizes constraints through user interaction. The core of the methodology consists of a passive learning module where subsets of variables are compared against global constraints and are validated using a CP solver. Constraints consistently present across multiple solution sets are identified as global constraints that belong to the model. Then, fixed arity constraints are refined through an active learning module with user input. Experiments across various problem types, from simple to complex, demonstrate the efficiency of the proposed hybrid methodology.
Quantum geometric approach: Nature and characteristics of emerged quantum-conditioned spacetime curvatures on three-sphere
Authors: Tawfik A. , Alshehri A.
Published: August 2024

General relativity (GR) in its current classical formulation is fundamentally different from quantum mechanics (QM). We argue that the everlasting battle for exploring and understanding the Universe and then privileging a consistent perception of reality is therefore awaiting a consolidator rather than a conqueror. This should be capable of either unifying these two different benchmarks or at least bringing one closer to another! The latter conservatively describes the consolidating quantum geometric approach, which combines generalization of QM to relativistic energies and gravitational fields and continuous Riemann to discretized Finsler geometry. We found that this type of quantum geometric approach seems to unveil additional quantum-conditioned spacetime curvatures (QCC), sources of gravitation), which obviously could not be disclosed in Einstein’s GR, especially at large scales. This study introduces analytical and numerical analyses of QCC. We conclude that (i) nature and characteristics of QCC are fundamentally distinguishable from the classical GR’s spacetime curvatures, (ii) the QCC are intrinsic, real and essential, i.e. not artifacts that would be removed in a certain coordinate transformation and (iii) the magnitude of QCC are nonnegligible to be underestimated. We also conclude that the spacetime at quantum scales seems to be no longer smooth or continuous so that the proposed quantum geometric approach would be regarded as a novel mathematical framework for the emergence of quantum gravity. Last but not least, a maximal proper force is predicted as a new physical constant, which is responsible for the maximal and gravitational acceleration of a quantum particle that would live in the emerged spacetime curvatures. Thereby, the quantum geometric nature of QCC can be accessed and assessed.
Maxwell field with gauge fixing term in the radiation- and matter-dominant stages: Exact solution and stress tensor
Authors: Ye Xuan , Zhang Yang
Published: August 2024

We study the Maxwell field with a general gauge fixing (GF) term in the radiation-dominant (RD) and matter-dominant (MD) stages of expanding Universe, as a continuation to the previous work in the de Sitter space. We derive the exact solutions, perform the covariant canonical quantization and obtain the stress tensor in the Gupta–Bleuler (GB) physical states, which is independent of the GF constant and is also invariant under the quantum residual gauge transformation. The transverse stress tensor is similar in all flat Robertson–Walker spacetimes, and its vacuum part is [Formula: see text] and becomes zero after the 0th-order adiabatic regularization. The longitudinal-temporal stress tensor, in both the RD and MD stages, is zero due to a cancelation between the longitudinal and temporal parts in the GB states, and so is the particle part of the GF stress tensor. The vacuum GF stress tensor, in the RD stage, contains [Formula: see text] divergences and becomes zero by the 2nd-order regularization, however, in the MD stage, contains [Formula: see text] divergences and becomes zero by the 4th-order regularization. So, the order of adequate regularization depends not only upon the type of fields, but also upon the background spacetimes. In summary, in both the RD and MD stages, as in the de Sitter space, the total regularized vacuum stress tensor is zero, independent of the GF constant, only the transverse photon part remains, there is no trace anomaly, and the vanishing GF stress tensor cannot be a candidate for the dark energy.
Virtual and resonance states in the three-body D−μ−−T, D−μ−−D systems
Authors: Mikhail Egorov
Published: August 2024

Three-body bound, virtual and resonant states in the [Formula: see text] and [Formula: see text] systems were found by solving homogeneous Faddeev equations on the real and complex energy planes. The formalism of searching is conducted for the scattering matrix poles on both physical and nonphysical energy sheets with an analytical continuation of the corresponding Lippmann–Schwinger equations for t-matrix. Some benchmark tests have been done with model and realistic two-body potentials to verify the analytical continuation procedure. Direct calculations revealed five resonant states in the [Formula: see text] and [Formula: see text] systems, as well as two virtual states in the [Formula: see text] system in the strong coupling mode. The key influence of short-range [Formula: see text] and [Formula: see text] interactions was found on the appearance of [Formula: see text] and [Formula: see text] bound states in the energy range of 1–20[Formula: see text]keV, which disappeared when such interactions were turned off.
NETTING AND NOVATION IN REPO NETWORKS
Authors: CHEHAITLI HASSAN , GRASSELLI MATHEUS R. , HURD THOMAS R. , PANG WEIJIE
Published: August 2024

We propose an agent-based computational model for a financial system consisting of a network of banks with interconnected balance sheets comprising fixed assets (e.g. loans to agents outside the network), liquid assets (e.g. cash or central bank reserves), general collateral (e.g. government debt), unsecured interbank loans and reverse-repos to other banks as assets, as well as deposits, unsecured interbank loans and repos from other banks as liabilities. Importantly, we allow banks to use reverse-repo assets as collateral for obtaining repo loans from other banks, that is to say, rehypothecation. Banks need to satisfy liquidity, collateral, and solvency constraints. If the first two constraints are violated because of internal or external shocks, solvent banks attempt to restore them by rebalancing their assets, which might lead to the propagation of the shock because of fire-sale effects (if fixed assets are sold) or liquidity hoarding (if secured or unsecured loans are recalled). Insolvent banks, as well as banks that failed to restore the liquidity and collateral constraints after rebalancing, are removed from the network using a resolution algorithm that includes a netting step (i.e. removal of closed cycles of liabilities) and a novation step (i.e. redistribution of repo assets and liabilities to remaining banks). We show analytically that this proposed resolution algorithm has several desirable properties, most importantly the order-independence of the novation step, and we investigate the stability properties of the network through a series of numerical experiments.
Active Control for Construction Stability of Suspension Arch Rib Segments Based on ARID System
Authors: Zhang Chunwei , Li Hao
Published: August 2024

In response to the issues of vibrations affecting the construction safety, speed, and accuracy of suspended structures due to dynamic disturbances during lifting, environmental disturbances, and improper operator actions, this paper investigates the application of the Active Rotary Inertia Driver (ARID) system for double-rope suspended structures, namely analyzes, and applies control to the vibration response of double-rope suspended structures under external excitations. Taking the double-rope suspended structure as an example, a dynamic analytical model of the double-rope suspended structure is established based on D’Alembert’s principle. Through shake table tests, the dynamic response characteristics and vibration control effects of the double-rope suspended structure under various external excitations are studied, and the influence of the twisting radius of the suspended structure on the control effect is analyzed. The experimental results show that the ARID control system achieves significant control effects on the swing and torsional vibrations of the suspended structure, which validates the accuracy of the theoretical model for the ARID control system and demonstrates its feasibility for practical applications.
Exploring Semi-Active TMD Performance on Lively Footbridges Considering Human–Structure Interaction in Vertical Direction
Authors: Soria J. M. , Jiménez-Alonso J. F. , Renedo C. M. C. , Gallegos-Calderón C.
Published: August 2024

Human–Structure Interaction (HSI) can significantly influence the dynamic characteristics of pedestrian footbridges, particularly those distinguished by their lightness and slenderness. This study examines the performance of Tuned Mass Dampers (TMD) and Semi-Active Tuned Mass Dampers (STMD) on pedestrian footbridges when their modal parameters change due to the influence of HSI. For this purpose, a 30 m long simply-supported footbridge with linear mass values ranging from 200[Formula: see text]kg/m to 2[Formula: see text]000[Formula: see text]kg/m and a fundamental frequency varying from 1[Formula: see text]Hz to 5[Formula: see text]Hz has been considered. In addition, several pedestrian streams with different pedestrian densities have been used to assess the structural dynamic response. The analysis highlights that structural lightness and slenderness are critical factors in determining whether the incorporation of an HSI model is relevant to accurately predict the dynamic performance of the structure. The findings indicate that while TMDs can become ineffective due to shifts in natural frequencies caused by HSI, resulting in a degradation of vibration reduction from 70–75% to 40–45%, STMDs demonstrate a robust capability to adjust and cope with these frequency changes, maintaining a higher average vibration reduction of around 55–60%. Consequently, STMDs emerge as a necessary solution for very slender structures where HSI significantly alters the global frequency response. This study highlights the importance of considering HSI in the design and implementation of damping solutions to ensure optimal functionality and user comfort on lightweight pedestrian bridges.
Dynamic Analysis of Rockfall Impact on Bridges: Implications for Train Safety
Authors: Liu Zhanhui , Wang Mingxi , Chen Keyu , Demartino Cristoforo , Li Yongle , Nikitas Nikolaos
Published: August 2024

The threat of rockfall impacting bridges in mountainous areas poses a great risk to the safety of passing trains. This study delves into the dynamics of rockfall impact and its implications on the interaction between train vehicles and bridges. Leveraging LS-DYNA, this study first captured the force–time history of rockfall impact on bridge structures. Subsequently, there was a comparison with the impact forces generated at various speeds with those predicted by established formulas, validating the accuracy of simulations. Employing BANSYS software, the dynamic responses of both bridge structures and the vehicle–bridge coupling system to falling rocks were analyzed. The investigation encompassed parameters such as impact speed, position, and train location. The findings reveal that escalating impact speeds correlate with increased average and maximum impact forces from falling rocks. Notably, the average impact force does not linearly correspond with rock speed and often exceeds values calculated by conventional formulas. Impact position minimally affects maximum impact force, yet alterations in position prolong impact duration, consequently reducing average impact force. Rockfall-induced impacts precipitate notable spikes in train lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient, albeit with a comparatively lesser impact on vertical acceleration. Increasing impact speed and altering position intensifies the vehicle’s response, particularly when the train is in close proximity to the impact site.
Control Mechanism and Noise Reduction Effect of CVDM on Rail Transit Steel Bridge: Experimental and Numerical Study
Authors: Bai Taoping , Ding Kang , Qi Xiaojun , Liang Lin , Li Xiaozhen , Liu Congfeng
Published: August 2024

Steel bridge, as one of the main structural types in bridge design, has been widely used in rail transit. However, the train-induced vibro-acoustic problem of the bridge has become increasingly prominent. The vibration and noise characteristics must be more significant and complex than steel truss bridge because of too many components. Viscoelastic damping materials (VDMs) have the characteristics of both viscous liquid and elastic solid, and have better damping performance than other damping materials. Therefore, VDM plays an important role in vibration and noise reduction technology. In applications, VDM is usually combined with constraining materials to form composite viscoelastic damping materials (CVDM). In this paper, based on the dynamic receptance method and superposition principle, the coupling model of vehicle–track–bridge in the frequency domain is first established, and then the vibration and noise prediction model of a steel truss bridge with CVDM is established based on RUK theory and statistical energy analysis (SEA) method. Based on the prediction model, the natural dynamic characteristics of typical components of steel truss bridges with CVDM were investigated, and the control mechanism and influence rule of CVDM on train-induced vibration and noise of steel bridges were revealed.
Investigation of 3D Bipedal Spring-Loaded Inverted Pendulum Human Walking Model on Laterally Vibrating Surfaces in the Case of Phase Drift, Phase Pulling, and Synchronization
Authors: Yang Haowen , Wang Zhen , Wu Bin , Bao Yu
Published: August 2024

Serviceability issues associated with structural lateral vibration are observed frequently, where human–structure interaction (HSI) plays a crucial role. Inverted pendulum (IP) models have attracted much attention from researchers due to their ability to naturally present human mechanical behaviors and significant advantages in studying the mechanisms of HSI. This paper investigates the behaviors of a 3D bipedal spring-loaded inverted pendulum (BSLIP) model while walking on laterally vibrating surfaces. First, we adopt feedback control strategies for the 3D BSLIP human walking model to achieve stable walking. Then, we investigate phase drift, phase pulling, and synchronization behaviors of the human body using the 3D BSLIP. The results indicate that the equivalent damping and mass coefficients of the 3D BSLIP basically agree with the available experimental results from the literature. Compared to the 3D IP model with rigid legs, the equivalent coefficients obtained from the 3D BSLIP exhibit similar ranges and trends as the control parameter increases. Furthermore, the 3D BSLIP and 3D IP models successfully replicate phase pulling and synchronization phenomena. The synchronization phase angles fall within the range of [Formula: see text]–[Formula: see text] for the 3D IP and [Formula: see text]–[Formula: see text] for the 3,D BSLIP model, consistent with the experimental results reported in the existing literature.
Analyzing the Progressive Collapse of a 230 KV Power Transmission Line Tower Structure and Investigation of the Effect of Environmental Factors
Authors: Ferdowsi Farideh , Hashemi Seyed Shaker , Sadeghi Kabir , Dashti Rahman
Published: August 2024

Electricity transmission lines constitute a vital element in any electrical power system. Nevertheless, the progressive collapse of these structures caused by accidental events and cascade failure can lead to a wide range of failures, including total collapse. The failure of power transmission line structures due to extreme wind and ice loads poses a substantial challenge for electrical power distribution companies globally. In this study, the progressive collapse behavior of a 230-kV electrical power transmission line in Fars Province, Iran was evaluated utilizing the alternative load path method within a nonlinear dynamic analysis framework. Finite element models of a tangent electricity tower (DC0), a terminal tower (DC90), and the conductors of the transmission line were created and simulated using SAP2000 software. The investigation focused on the impact of removing the legs of the transmission tower, and the simulation analyzed the progressive collapse behavior under various loading conditions, including wind load, snow-induced freezing, and simultaneous wind and ice load. By employing the nonlinear dynamic analysis of the progressive collapse, the stresses developed in the structural elements were evaluated, and the damaged elements were identified. The results demonstrated that following the failure of one leg, the tangent and terminal towers remained stable under gravitational loads. However, under extreme winds at a [Formula: see text] angle, the failure of a leg resulted in significant damage to the towers. Further assessment of the tangent and terminal towers revealed that the terminal tower exhibited higher strength compared to the tangent tower. This was evident in the lower dispersion of displacements and a reduced number of damaged elements observed in the terminal tower when one leg was removed.
Buckling Analysis of Variable Stiffness Composite Cylindrical Shells Under Axial Compression Considering Imperfection Sensitivity
Authors: Hou Yihang , Fan Haigui , Gu Wenguang
Published: August 2024

Thin-walled composite cylindrical shells are nowadays widely used as primary structures in the aerospace industry. The so-called variable stiffness (VS) composite cylindrical shells with flexible stiffness tailoring characteristics have been made possible by existing AFP techniques. Considering the inherent imperfection sensitivity property of axially compressed thin-walled cylindrical shells, the buckling behaviors of the axially compressed VS composite cylindrical shells with initial geometric imperfections and delamination imperfections are investigated respectively in this paper. The design buckling loads of the axially compressed VS composite cylindrical shells are first determined by the probing method, which is verified by comparing with the existing test data and numerical simulation results. Additionally, a parametric study is conducted to investigate the effects of delamination imperfections on the buckling loads. The constraint delamination sizes of the VS composite cylindrical shells based on the design buckling load in this paper are given. Furthermore, the effects of continuously variable fiber angles on the buckling loads are investigated considering the imperfection sensitivity. The specific VS composite cylindrical shells with both high- buckling loads and low-imperfection sensitivity are obtained. Results indicate that the effects of imperfection sensitivity need to be carefully considered in buckling design of the axially compressed VS composite cylindrical shells.
Ultra-Low-Frequency Energy Harvesting in Quasi-Zero Stiffness Systems with Inertial Amplifiers Under Mixed Harmonic Excitation
Authors: Wang Xinzong , Kang Xiaofang , Xia Guanghui , Zhang Cheng
Published: August 2024

In this paper, an inertial amplifier and a quasi-zero stiffness system are combined to propose an energy harvesting system that can change the dynamic mass of the system. By adjusting the inertial amplifier, it is possible to change the distribution of its chaotic region and the effective range of energy collection. The kinetic equations of the system with an inertial amplifier under a combination of multiple harmonic excitations are developed. Based on this, the system was simulated and tested and the Lyapunov exponent, the RMS value of the induced voltage and the coexisting basins of attraction were plotted. Subsequently, the best optimization solution to improve the energy harvesting efficiency of the system was identified. In addition, the system was tested for impulse excitation based on the given coexisting basins of attraction. The simulation results show that the inertial amplifier can effectively improve the range of the energy harvesting region and the distribution of the chaotic region in the system ground under ultra-low-frequency vibration. The initiation of impulse excitation can change the energy harvesting performance of the system to a great extent.
Time-Dependent Analysis of Reinforced Concrete Two-Way Slabs Strengthened with External FRP and Steel Plates
Authors: Amer Omar Z. , Mahmoud Akram S. , Radi Aleaa B.
Published: August 2024

This study aims to predict the long-term behavior of fiber-reinforced plastic (FRP) or steel plates externally strengthening RC two-way slabs using ANSYS software non-linear finite element (FE) modeling and making a comparison between the FE analysis with the experimental test results, in addition, calculated the effect of parameters on the strengthened slab behavior: compressive strength, the magnitude of sustained load, slab length to slab thickness, and the external strengthening type. The Prony series were used in the model of non-linear viscoelastic in this paper to study the deflection of time-dependent adopted. The modeling was done to solve the problems of the creep by the FEs by ANSYS software, the results showed an acceptable agreement level with the results of the experiment. The parametric study’s numerical results indicate that as sustained load increases for 20–60% Pu kN, the time-dependent deflection increases by around 2.5 times, as well as a decrease in the long-term efficiency of the slabs that external strengthening where the deflection is increased due to increased creep, and the effect creep has on the deflection.
On the ϕ-weak global dimensions of polynomial rings and ϕ-Prüfer rings
Authors: Kim Hwankoo , Mahdou Najib , Oubouhou El Houssaine
Published: August 2024

This paper focuses on the study of [Formula: see text]-weak global dimensions in the context of polynomial rings and [Formula: see text]-Prüfer rings. We explore new properties of these dimensions and extend the Hilbert syzygy theorem to [Formula: see text]-weak global dimensions of rings. We also determine the [Formula: see text]-weak global dimension for certain types of [Formula: see text]-Prüfer rings. Key concepts such as [Formula: see text]-flat modules, [Formula: see text]-injective modules, and [Formula: see text]-torsion modules are discussed, along with their hereditary properties in PN-rings. This paper includes several theorems and lemmas that provide insights into the [Formula: see text]-weak global dimensions and their implications in the field of ring theory.
Orbit problems for free-abelian times free groups and related families
Authors: Carvalho André , Delgado Jordi
Published: August 2024

We prove that the Brinkmann Problems ( BrP & BrCP ) and the Twisted-Conjugacy Problem ( TCP ) are decidable for any endomorphism of a free-abelian times free (FATF) group [Formula: see text]. Furthermore, we prove the decidability of the two-sided Brinkmann Conjugacy Problem ( 2BrCP ) for monomorphisms of FATF groups (and combine it with TCP ) to derive the decidability of the conjugacy problem for ascending HNN extensions of FATF groups.
The eventual shape of the Betti table of 𝔪kM
Authors: Ficarra Antonino , Herzog Jürgen , Moradi Somayeh
Published: August 2024

Let [Formula: see text] be a standard graded polynomial ring over a field [Formula: see text] in a finite set of variables, and let [Formula: see text] be the graded maximal ideal of [Formula: see text]. It is known that for a finitely generated graded [Formula: see text]-module [Formula: see text] and all integers [Formula: see text], the module [Formula: see text] is componentwise linear. For large [Formula: see text] we describe the pattern of the Betti table of [Formula: see text] when [Formula: see text]. Moreover, we show that for any [Formula: see text], [Formula: see text] has linear quotients if [Formula: see text] is a monomial ideal.
Sound Insulation Characteristics of Sandwich Thin-Plate Acoustic Metamaterial: Analysis and Optimization
Authors: Tang Yang , Wei Jianhui , Qin Yuxuan , Gao Jincheng , Du Yuan , Pang Fuzhen
Published: August 2024

Addressing the demand for low-frequency noise control in ships and aiming to overcome the limitations imposed by the mass law of traditional materials, a sandwich thin-plate acoustic metamaterial (SPAM) was developed in this study. This structure is characterized by its simplicity and superior sound insulation performance. A sound insulation test was conducted to validate the exceptional low-frequency acoustic suppression capability of SPAM, and the effectiveness of the analytical model was also demonstrated. Subsequently, based on this model, a sensitivity analysis of the sound insulation characteristics of the SPAM relative to structural parameters was carried out. For the optimization process, the Logistic-Sine fusion chaotic mapping was employed to refine the dung beetle optimizer (DBO), enhancing the initial population distribution. The improved dung beetle optimizer (IDBO) was then used to further optimize and elevate the sound insulation performance of the SPAM. The outcomes indicate that the IDBO boasts superior optimization proficiency and accelerated convergence, while the optimized SPAM exhibits more remarkable sound insulation capabilities. Within the frequency range of 100–315 Hz, the average sound transmission loss (STL) has increased by 11.94 dB when compared to the pre-optimization values.