bluuebunny/crossref_metadata_2025 huggingface dataset:
Yolk–shell type carbon–silica nanoarchitecture with dispersed and stabilized Ru nanoparticles for enhanced hydrogenation of aromatic compounds
Authors: Yan Lu , Shen Yue , Zou Zidan , Zhang Xiao , Yu Zhixin , Wang Guozhong , Chen Chun
Published: April 2024

A yolk–shell type carbon–silica nanoarchitecture with dispersed and stabilized Ru nanoparticles was successfully synthesized for enhanced hydrogenation of aromatic compounds.
Mechanochemically-induced glass formation from two-dimensional hybrid organic–inorganic perovskites
Authors: Ye Chumei , Lampronti Giulio I. , McHugh Lauren N. , Castillo-Blas Celia , Kono Ayano , Chen Celia , Robertson Georgina P. , Nagle-Cocco Liam A. V. , Xu Weidong , Stranks Samuel D. , Martinez Valentina , Brekalo Ivana , Karadeniz Bahar , Užarević Krunoslav , Xue Wenlong , Kolodzeiski Pascal , Das Chinmoy , Chater Philip , Keen David A. , Dutton Siân E. , Bennett Thomas D.
Published: April 2024

We present the crystal-glass transformation of two-dimensional hybrid organic–inorganic perovskites (HOIPs) via ball-milling.
Bio-inspired design of a self-supported bismuth microforest for high performance sodium storage
Authors: Bai Jia , Liu Yan , Pu Ben , Tang Qi , Wang Yongbin , Yuan Ruihan , Cui Jin , Yang Yi , Zheng Xiaojia , Zhou Bin , Yang Weiqing
Published: April 2024

A self-supported bismuth microforest anode material, prepared by a simple, efficient and scalable in situ galvanic replacement approach, exhibits high performance for sodium-ion batteries.
A red thermally activated delayed fluorescence emitter with mitigated efficiency roll-off via a π-stacked multiple donor–acceptor structure
Authors: Song Min , Yu You-Jun , Feng Zi-Qi , Qu Zhi-Hao , Zuo Peng , Yan Hong-Yan , Jiang Zuo-Quan , Zhou Dong-Ying , Liao Liang-Sheng
Published: April 2024

The TADF emitter TCPP-DTPA with a multilayered π-stacked structure accelerates the RISC process and achieves extremely low-efficiency roll-off in red OLEDs.
Self-Reported Home Program Adherence by People With Aphasia: Exploring Construct Validity
Authors: Wallace Sarah E. , Donoso Brown Elena V. , Lee Jaime B. , Janov Katherine L. , Busquets Mariana Pachecho
Published: April 2024

Purpose:

The study purpose was to compare the practice patterns captured by self-reported logbook data and those recorded by a computerized home program application. The current study is part of a larger single-case research design study aimed at investigating the effect of logbook use on home program adherence in people with aphasia poststroke.

Method:

Data from six adults with chronic aphasia with interest in improving their reading were used in this secondary analysis. Participants completed reading comprehension therapy tasks using a mobile application and tablet. The activities were self-directed and designed for people with aphasia to complete independently. We created an aphasia-friendly logbook based on best practices to allow participants to record their estimated total minutes practiced. Participants received instructions to practice the reading therapy application 80 min a day 7 days a week for the duration of the study. We calculated the difference in the total time per day recorded by each participant to the application data collected.

Results:

All participants used the logbook to record their practice. There was a strong relationship between self-reported logbook practice and application-recorded practice for four of the six participants. Individual differences were noted and explored.

Conclusion:

These results suggest that some people with aphasia can use logbooks with aphasia-friendly modifications to accurately estimate the amount of practice completed outside of therapy sessions.
Parent and Child Experiences of Bone-Conduction Hearing Devices for Unilateral Microtia–Atresia: Decisions and Outcomes
Authors: Edwards Lindsey , Middleton-Curran Laura , Wright Gillian , Rooney Natasha , Wong Anita , Hill Rebecca , Bulstrode Neil , Nash Robert
Published: April 2024

Purpose:

The decision to proceed with bone-conduction hearing devices is not an easy one despite being the audiological management of choice for the majority of children with unilateral hearing loss secondary to microtia–atresia, and the outcome is not always as hoped for. This study aimed to explore parent and child views on decision making and outcomes.

Method:

Qualitative methods (focus groups and individual interviews) were used to explore parent and child opinions on factors influencing the decision to try a bone-conduction device and their subsequent use or nonuse. Quantitative methods (questionnaires) investigated the impact of hearing loss on listening effort and fatigue, quality of life, and learning, including executive functions such as working memory, information processing, and attention. Twelve parent–child dyads participated in the study, with children aged 9–14 years.

Results:

A thematic analysis of qualitative data highlighted the importance to parents of timely, consistent, and accessible device information as well as concerns regarding bullying, psychosocial well-being, and educational impacts. Children's concerns included feeling different from their peers, bullying, device appearance, and sound quality, as well as the support they wanted and received. Questionnaire results provided useful confirmatory information on the impacts of unilateral hearing loss on learning for a substantial proportion of the children in this sample.

Conclusion:

The findings provide insights into the wide range of issues that have implications for the provision of audiological services as well as educational and psychological support for children with unilateral microtia–atresia.

Supplemental Material:

https://doi.org/10.23641/asha.25583361
Protostellar disk accretion in turbulent filaments
Authors: Heigl S. , Hoemann E. , Burkert A.
Published: April 2024

Context. Recent observations of protostellar cores suggest that most of the material in the protostellar phase is accreted along streamers. Streamers in this context are defined as velocity coherent funnels of denser material potentially connecting the large-scale environment to the small scales of the forming accretion disk.

Aims. Using simulations that simultaneously resolve the driving of turbulence on the filament scale as well as the collapse of the core down to protostellar disk scales, we aim to understand the effect of the turbulent velocity field on the formation of overdensities in the accretion flow.

Methods. We performed a three-dimensional numerical study on a core collapse within a turbulent filament using the RAMSES code and analysed the properties of overdensities in the accretion flow.

Results. We find that overdensities are formed naturally by the initial turbulent velocity field inherited from the filament and subsequent gravitational collimation. This leads to streams that are not really filamentary but show a sheet-like morphology. Moreover, they have the same radial infall velocities as the low density material. As a main consequence of the turbulent initial condition, the mass accretion onto the disk does not follow the predictions for solid body rotation. Instead, most of the mass is funneled by the overdensities to intermediate disk radii.
Fermi-LAT follow-up observations in seven years of real-time high-energy neutrino alerts
Authors: Garrappa S. , Buson S. , Sinapius J. , Franckowiak A. , Liodakis I. , Bartolini C. , Giroletti M. , Nanci C. , Principe G. , Venters T. M.
Published: April 2024

The realtime program for high-energy neutrino track events detected by the IceCube South Pole Neutrino Observatory releases alerts to the astronomical community with the goal of identifying electromagnetic counterparts to astrophysical neutrinos. Gamma-ray observations from theFermi-Large Area Telescope (LAT) enabled the identification of the flaring gamma-ray blazar TXS 0506+056 as a likely counterpart to the neutrino event IC-170922A. By continuously monitoring the gamma-ray sky,Fermi-LAT plays a key role in the identification of candidate counterparts to realtime neutrino alerts. In this paper, we present theFermi-LAT strategy for following up high-energy neutrino alerts applied to seven years of IceCube data. Right after receiving an alert, a search is performed in order to identify gamma-ray activity from known and newly detected sources that are positionally consistent with the neutrino localization. In this work, we study the population of blazars found in coincidence with high-energy neutrinos and compare them to the full population of gamma-ray blazars detected byFermi-LAT. We also evaluate the relationship between the neutrino and gamma-ray luminosities, finding different trends between the two blazar classes BL Lacs and flat-spectrum radio quasars.
Diabetische Nephropathie und Progressionsverlangsamung der CKD
Authors: Krüger Thilo
Published: April 2024

Die Verlangsamung des Krankheitsverlaufs bei chronischer Nierenkrankheit (CKD: „chronic kidney disease“) stellt eine wesentliche, wenn nicht die wesentlichste Aufgabe von Nephrologinnen und Nephrologen dar. Aufgrund der Häufigkeit von Diabetes mellitus kommt der diabetischen Nephropathie dabei ein bedeutender Stellenwert zu. Erfreulicherweise haben sich in den letzten Jahren zahlreiche Neuerungen in Bezug auf therapeutische Möglichkeiten ergeben. Dieser Artikel fasst sowohl altbekannte als auch neue Behandlungsmethoden zur Progressionsverlangsamung der diabetischen Nephropathie zusammen.
Terminüberschreitung
Authors: Hünig Johanna
Published: April 2024

Warten oder Handeln?

Pünktlichkeit ist eine Tugend – jedoch nicht immer notwendig. Nur ein sehr kleiner Teil der Kinder
wird tatsächlich am errechneten Termin geboren. Die Ansicht darüber, wann ein Kind als kritisch
zu spät dran ist, variiert. Während im deutschsprachigen Raum 40+0 SSW als errechneter Termin
und die Zeit bis 41+6 SSW als Terminüberschreitung bezeichnet wird, gilt in Norwegen 40+3 SSW
als Termin und ≥42+3 SSW als Übertragung. Manchmal wird ein Kind bereits in der 38. SSW intrauterin
nicht mehr ausreichend gut versorgt. In anderen Fällen geht es dem Kind auch bei 42+5
SSW noch gut oder es überrascht uns dann mit reichlich Vernix bei der Geburt.
Entscheidungsfindung zum Vorgehen bei
Terminüberschreitung
Authors: Schwarz Christiane , Hünig Johanna
Published: April 2024

Einleiten oder nicht? Vor dieser Entscheidung stehen Ärzt*innen, Hebammen und
Schwangere im geburtshilflichen Alltag ständig. Kann hier eine Analyse der
Perinataldaten Sicherheit bringen? Prof. Dr. Christiane Schwarz ist Professorin
für Hebammenwissenschaft an der Universität zu Lübeck und beschäftigt sich seit
vielen Jahren intensiv mit den Zusammenhängen zwischen Schwangerschaftsalter und
Sterblichkeit. Im Gespräch mit Johanna Hünig, Hebamme und wissenschaftliche
Mitarbeiterin an der ZHAW, erklärt sie, welche Schwierigkeiten mit Daten und
Studien verbunden sind und warum es so wichtig ist, dass Hebammen sich beim
Thema Terminüberschreitung und Geburtseinleitung in der Forschung
engagieren.
The Vladimirov operator with variable coefficients on finite adeles and the Feynman formulas for the Schrödinger equation
Authors: Urban Roman
Published: April 2024

We construct the Hamiltonian Feynman, Lagrangian Feynman, and Feynman–Kac formulas for the solution of the Cauchy problem with the Schrödinger operator −MgDα − V, where Dα is the Vladimirov operator and Mg is the operator of multiplication by a real-valued function g defined on the d-dimensional space AKd of finite adeles over the algebraic number field K.
Delay-driven phase transitions in an epidemic model on time-varying networks
Authors: Wang Wen , Chen Guanrong , Wong Eric W. M.
Published: April 2024

A complex networked system typically has a time-varying nature in interactions among its components, which is intrinsically complicated and therefore technically challenging for analysis and control. This paper investigates an epidemic process on a time-varying network with a time delay. First, an averaging theorem is established to approximate the delayed time-varying system using autonomous differential equations for the analysis of system evolution. On this basis, the critical time delay is determined, across which the endemic equilibrium becomes unstable and a phase transition to oscillation in time via Hopf bifurcation will appear. Then, numerical examples are examined, including a periodically time-varying network, a blinking network, and a quasi-periodically time-varying network, which are simulated to verify the theoretical results. Further, it is demonstrated that the existence of time delay can extend the network frequency range to generate Turing patterns, showing a facilitating effect on phase transitions.
Comparison of density profiles measured via laser interferometry with MHD simulations during shock wave reflection on mega-ampere dense plasma focus
Authors: Malir J. , Klir D. , Cikhardt J. , Cikhardtova B. , Kravarik J. , Kubes P. , Munzar V. , Novotny J. , Rezac K. , Paduch M.
Published: April 2024

The analysis of Z-pinch implosion dynamics plays one of the most important roles in the study of pulsed power discharges. At the same time, it is difficult to determine the density distribution together with the current density (current coupling to the imploding layer) to provide more detailed information about the dynamics. Numerical simulations can now provide high-resolution results that are almost unattainable in experiments. The challenge, however, is to obtain reliable results that are close enough to the experimental data to describe individual physical phenomena. In this paper, we show that it is possible to use a combination of experimental data and magnetohydrodynamic (MHD) simulations to verify and identify the physical processes during the stagnation of a Z-pinch. We focus on the analysis of the density profile from experimental data of the mega-ampere plasma focus PF-1000 and its reconstruction using an extended MHD code. Thanks to multi-frame interferometry, we recorded a total of 29 interferometric images of two shots, each in a 200 ns time window around the pinch phase. We were then able to obtain density profiles and observe the reflection of the shock wave from the axis. By the appropriate choice of initial conditions and boundary values in the simulation, we were able to obtain reasonable agreement with the experimental values. We also evaluated the possible shortcomings of the 1D simulation, such as mass loss and current flow at the periphery.
Searching for chaotic behavior in the experimental ion current and discharge current waveforms of a Hall effect thruster
Authors: Jardin A. , Lubiński P.
Published: April 2024

This work concerns the experimental study of the plasma emitted by a Hall effect thruster in the context of chaotic behavior. Its aim was to check whether low-dimensional deterministic chaos could explain the fluctuations observed in the current waveforms: discharge current and ion current measured by a planar probe with a guarding ring. The discharge voltage was used as a control parameter, and the dependence of the thruster efficiency on this parameter was studied. Several standard chaos diagnosis tools, such as the presence of attractors with non-integral dimensions, the specific shape of Poincaré cross sections, and the positive values of the largest Lyapunov exponent, provided a strong evidence for deterministic chaos in the tested current waveforms. This chaotic behavior occurred when the thruster was operating in the global mode of oscillations dominated by so-called breathing oscillations, adversely affecting the operation of the device.
Theoretical and practical investigation of ion–ion association in electrolyte solutions
Authors: Naseri Boroujeni Saman , Maribo-Mogensen B. , Liang X. , Kontogeorgis G. M.
Published: April 2024

In this study, we present a new equation of state for electrolyte solutions, integrating the statistical associating fluid theory for variable range interactions utilizing the generic Mie form and binding Debye–Hückel theories. This equation of state underscores the pivotal role of ion–ion association in determining the properties of electrolyte solutions. We propose a unified framework that simultaneously examines the thermodynamic properties of electrolyte solutions and their electrical conductivity, given the profound impact of ion pairing on this transport property. Using this equation of state, we predict the liquid density, mean ionic activity coefficient, and osmotic coefficient for binary NaCl, Na2SO4, and MgSO4 aqueous solutions at 298.15 K. Additionally, we evaluate the molar conductivity of these systems by considering the fraction of free ions derived from our equation of state in conjunction with two advanced electrical conductivity models. Our results reveal that, while ion–ion association has a minimal influence on the modification of the predicted properties of sodium chloride solutions, their impact on sodium and magnesium sulfate solutions is considerably more noticeable.
An optimal hybrid control strategy for supporting frequency regulation considering fatigue load mitigation of wind turbines
Authors: Fu Lei , Deng Xi , Liu Jia , Zhang Hao , Weng Zhengqiu , Cheng Shuhao , Xu Fang , Ouyang Jing
Published: April 2024

Frequency regulation of wind turbines can improve the stability of the power system. However, it would cause generator torque fluctuation, increasing the risk of fatigue load. Previous research works were restricted to inertial and droop responses. Less attention has been paid to striking a balance between frequency regulation and fatigue load. To overcome these, a hybrid control strategy is proposed to consider both frequency response characteristic and fatigue load mitigation. First, a small signal linearization model is built to reveal the impact of the correlation mechanism of frequency regulation on drive train torque load. Second, a multivariable cost function is constructed to optimize the proportional integral (PI) controller, which combines the total fluctuation with the dispersion of the fatigue load and frequency. Then, a hybrid controller based on PI control optimized by particle swarm optimization algorithm and active disturbance rejection control is designed to restrain rapid frequency changes as well as fatigue torque fluctuation simultaneously. Several experiments are performed to verify the significance of the proposed method under different scenarios. Compared with the existing methods, the proposed hybrid control exhibits superiority in improving frequency response and fatigue load mitigation.
Experimental and numerical studies on multi-jet impingement flow characteristics in a double-wall structure under rotating conditions
Authors: You Ruquan , Liu Zexuan , Li Haiwang , Liu Song , Tao Zhi
Published: April 2024

This study employs time-resolved particle image velocimetry technology to investigate the flow field characteristics of a double-wall jet structure under both stationary and rotating conditions. The jet rotation number range from 0 to 0.08, covering both clockwise and counterclockwise rotations, with a jet Reynolds number of 4000. The dimensionless jet-to-target spacing is 2. In order to elucidate the flow mechanisms based on experimental results and provide complementary insight, validated numerical simulations under conditions identical to the experiments were conducted. This paper considers average velocity and Reynolds stress and utilizes the proper orthogonal decomposition method to study flow characteristics. The results indicate that the rotation-induced Coriolis force, centrifugal force, and radial pressure gradient in the radial direction influence the jet to deflect. The pressure gradient generated by the centrifugal force weakens its effect, making the jet deflection primarily dominated by the Coriolis force. The deflection direction and degree of the jet differ with the rotation direction and increase with the rotation number. When the rotation direction is reversed, differences in the direction of the force acting on the fluid lead to variations in the secondary flow structures of the jet; the secondary flow structures within the impingement holes exhibit two-vortex or four-vortex structures under counterclockwise or clockwise rotation, respectively. At the highest rotation number, jet deflection intensifies mixing with the surrounding fluid, resulting in a reduction of about 30% in the velocity peak compared to the stationary state but an increase of approximately 0.6 times in turbulent kinetic energy.
Kinetic theory analysis of microscale lubrication of a gas between eccentric circular cylinders with an arbitrary temperature difference
Authors: Doi Toshiyuki
Published: April 2024

A microscale lubrication flow of a gas between eccentric circular cylinders with an arbitrary temperature difference is studied on the basis of kinetic theory. The dimensionless curvature, defined as the mean clearance divided by the radius of the inner cylinder, is small, whereas the temperature ratio and the Knudsen number based on the mean clearance take arbitrary values. The Bhatnagar–Gross–Krook–Welander (BGKW) model of the Boltzmann equation in bipolar coordinates is studied analytically using the slowly varying approximation. The leading-order term of the perturbation, which ought to be the solution of the nonlinear heat transfer problem, is replaced by the free molecular solution or an equilibrium solution at rest. Two macroscopic lubrication models are derived, along with a numerical database that enables one to use the models quickly. Direct numerical analysis of the BGKW equation is also conducted, and the validity of the lubrication models is assessed. The heating of either cylinder enhances both the eccentric force and the torque acting on the inner cylinder. When the Knudsen number is small, there is little difference in the eccentric force between the cases in which the rotating inner cylinder is heated and the stationary outer cylinder is heated. However, this difference becomes significant as the Knudsen number increases, with heating of the outer cylinder yielding the greater eccentric force. If the two lubrication models are applied complementarily depending on the Knudsen number, they provide a reasonable result for the eccentric force over a wide range of the Knudsen number.
Flow and noise control of a cylinder using grooves filled with porous material
Authors: Moradi Mohammad Amin , Mojra Afsaneh
Published: April 2024

In the present numerical study, we propose a new passive flow control mechanism at the Reynolds number of 3900. The novel method benefits from making grooves in the cylinder wall while the grooves are filled with porous materials of a specific permeability. According to the literature survey, while the porous medium is potentially an effective noise control method, it has serious drawbacks, mainly significant pressure drop. In the present study, instead of a porous coating, porous fillers are introduced offering substantial reduction of the noise level, in addition to managing the hydrodynamic parameters. To find a suitable design for the grooves and porous fillers, a systematic parametric study is performed on the number, sequence and size of the grooves, as well as the porous fillers' permeabilities. Based on the results, the newly proposed method dominated the traditional full porous coating by limiting the turbulent kinetic energy (TKE). The results of the parametric study indicated that grooves at an angle of 90° relative to the front stagnation point reduced the overall sound pressure level (OASPL) by 1.25 dB; meanwhile, the high-intensity TKE region shrunk. Further reductions were achieved by deeper grooves and porous fillers, as the drag coefficient, the lift coefficient, the Strouhal number, and the OASPL reduced up to 40.2%, 27.4%, 10.6%, and 3 dB, respectively. The proposed passive control method will be helpful for various industrial applications of cylinders through rigorous control of aerodynamic parameters and the noise level.
Study on the influence of collision conditions on the surface morphology of compound droplets
Authors: Lv Chao , Ji Zhaoxiang , Chen Junfeng , Yang Tao , Zhao Hongliang , Zhang Haiwei
Published: April 2024

In this study, a three-dimensional compound droplet collision numerical model is established by using volume of fluid. The morphological evolution of compound hollow droplets affected by high-speed solid droplet was studied in detail. Parameterized analysis is conducted on the velocity VS, center distance ϕ, and diameter ζ of high-speed small droplets. Through the analysis of the compound droplets flow field, it is found that the broken mode of compound droplets is caused by the increase in Pn (dimensionless pressure) and θ (velocity angle). The results show that the surface Pn of compound droplets is positively correlated with the velocity VS of high-speed small droplets, while there is a more complex relationship with the dimensionless center distance ϕ and dimensionless diameter ζ. When the values of ϕ and ζ are appropriate, Pn can reach its maximum value. The broken mode of compound droplets can be divided into three categories: shear deformation, shear crushing, and violent crushing.
Improving the market for household livestock production to alleviate food insecurity in the Philippines
Authors: Duong Minh-Phuong Thi , Sari Ni Putu Wulan Purnama , Mazenda Adrino , Nguyen Minh-Hoang , Vuong Quan-Hoang
Published: April 2024

Context Food security is one of the major concerns in the Philippines. Although livestock and poultry production accounts for a significant proportion of the country’s agricultural output, smallholder households are still vulnerable to food insecurity. Aims The current study aims to examine how livestock production and selling difficulties affect food-insecure conditions of smallholder households. Methods The study employed the mindsponge theory as its theoretical foundation for constructing the models. Subsequently, it applied the Bayesian mindsponge framework (BMF) analytics to analyse a dataset sourced from the Data in Emergencies Monitoring (DIEM) system of the Food and Agriculture Organization. Key variables in the dataset were transformed into indicators, enabling a detailed examination of smallholder livestock farmers’ difficulties in production or selling over the past 3 months. Production difficulties include hurdles in raising and producing livestock, covering aspects such as resource acquisition, animal health, and breeding. Selling difficulties involve obstacles in selling livestock products, including issues related to market access, pricing, and transportation. Key results Production and selling difficulties significantly adversely affect food security in the Philippines, with varying impacts according to the severity of food insecurity. In particular, production and selling difficulties equally affect the households’ likelihood of eating less healthy and nutritious food. However, the production difficulties have more negligible impacts on the possibility of skipping meals than do selling difficulties, and even ambiguous impacts on the likelihood of not eating for a whole day compared with the effects of selling difficulties. Moreover, we also found that the market plays a crucial role in facilitating not only livestock trading but also livestock production (e.g. purchase of feed and medicines). Conclusions Our research has highlighted the complex connection among livestock, markets, and food security within the Philippine setting. It emphasised the significant impact of selling difficulties, particularly the heavy reliance on nearby local and regional markets, in exacerbating the severity of food insecurity. Implications On the basis of these findings, we suggest that the livestock market needs to be expanded and regulated to balance livestock products and services used for livestock production and facilitate the product-exchanging mechanism.
Developing a predictive science of the biosphere requires the integration of scientific cultures
Authors: Enquist Brian J. , Kempes Christopher P. , West Geoffrey B.
Published: April 2024

Increasing the speed of scientific progress is urgently needed to address the many challenges associated with the biosphere in the Anthropocene. Consequently, the critical question becomes: How can science most rapidly progress to address large, complex global problems? We suggest that the lag in the development of a more predictive science of the biosphere is not only because the biosphere is so much more complex, or because we do not have enough data, or are not doing enough experiments, but, in large part, because of unresolved tension between the three dominant scientific cultures that pervade the research community. We introduce and explain the concept of the three scientific cultures and present a novel analysis of their characteristics, supported by examples and a formal mathematical definition/representation of what this means and implies. The three cultures operate, to varying degrees, across all of science. However, within the biosciences, and in contrast to some of the other sciences, they remain relatively more separated, and their lack of integration has hindered their potential power and insight. Our solution to accelerating a broader, predictive science of the biosphere is to enhance integration of scientific cultures. The process of integration—Scientific Transculturalism—recognizes that the push for interdisciplinary research, in general, is just not enough. Unless these cultures of science are formally appreciated and their thinking iteratively integrated into scientific discovery and advancement, there will continue to be numerous significant challenges that will increasingly limit forecasting and prediction efforts.
AI model disgorgement: Methods and choices
Authors: Achille Alessandro , Kearns Michael , Klingenberg Carson , Soatto Stefano
Published: April 2024

Over the past few years, machine learning models have significantly increased in size and complexity, especially in the area of generative AI such as large language models. These models require massive amounts of data and compute capacity to train, to the extent that concerns over the training data (such as protected or private content) cannot be practically addressed by retraining the model “from scratch” with the questionable data removed or altered. Furthermore, despite significant efforts and controls dedicated to ensuring that training corpora are properly curated and composed, the sheer volume required makes it infeasible to manually inspect each datum comprising a training corpus. One potential approach to training corpus data defects is model disgorgement, by which we broadly mean the elimination or reduction of not only any improperly used data, but also the effects of improperly used data on any component of an ML model. Model disgorgement techniques can be used to address a wide range of issues, such as reducing bias or toxicity, increasing fidelity, and ensuring responsible use of intellectual property. In this paper, we survey the landscape of model disgorgement methods and introduce a taxonomy of disgorgement techniques that are applicable to modern ML systems. In particular, we investigate the various meanings of “removing the effects” of data on the trained model in a way that does not require retraining from scratch.
Quantum network utility: A framework for benchmarking quantum networks
Authors: Lee Yuan , Dai Wenhan , Towsley Don , Englund Dirk
Published: April 2024

The central aim of quantum networks is to facilitate user connectivity via quantum channels, but there is an open need for benchmarking metrics to compare diverse quantum networks. Here, we propose a general framework for quantifying the performance of a quantum network by estimating the value created by connecting users through quantum channels. In this framework, we define the quantum network utility metricUQNto capture the social and economic value of quantum networks. The proposed framework accommodates a variety of applications from secure communications to distributed sensing. As a case study, we investigate the example of distributed quantum computing in detail. We determine the scaling laws of quantum network utility, which suggest that distributed edge quantum computing has more potential for success than its classical equivalent. We believe the proposed utility-based framework will serve as a foundation for guiding and assessing the development of quantum network technologies and designs.
Quantization avoids saddle points in distributed optimization
Authors: Bo Yanan , Wang Yongqiang
Published: April 2024

Distributed nonconvex optimization underpins key functionalities of numerous distributed systems, ranging from power systems, smart buildings, cooperative robots, vehicle networks to sensor networks. Recently, it has also merged as a promising solution to handle the enormous growth in data and model sizes in deep learning. A fundamental problem in distributed nonconvex optimization is avoiding convergence to saddle points, which significantly degrade optimization accuracy. We find that the process of quantization, which is necessary for all digital communications, can be exploited to enable saddle-point avoidance. More specifically, we propose a stochastic quantization scheme and prove that it can effectively escape saddle points and ensure convergence to a second-order stationary point in distributed nonconvex optimization. With an easily adjustable quantization granularity, the approach allows a user to control the number of bits sent per iteration and, hence, to aggressively reduce the communication overhead. Numerical experimental results using distributed optimization and learning problems on benchmark datasets confirm the effectiveness of the approach.
Congruence modules in higher codimension and zeta lines in Galois cohomology
Authors: Iyengar Srikanth B. , Khare Chandrashekhar B. , Manning Jeffrey , Urban Eric
Published: April 2024

This article builds on recent work of the first three authors where a notion of congruence modules in higher codimension is introduced. The main results are a criterion for detecting regularity of local rings in terms of congruence modules, and a more refined version of a result tracking the change of congruence modules under deformation. Number theoretic applications include the construction of canonical lines in certain Galois cohomology groups arising from adjoint motives of Hilbert modular forms.
Delimitación, visualización y metalenguaje
Authors: Carbajal-Carrera Beatriz
Published: April 2024

Abstracta

El presente artículo adopta el marco teórico del Diseño Universal para el Aprendizaje (DUA) como acercamiento cualitativo para examinar la accesibilidad de la enseñanza de las emociones en los manuales de español lengua extranjera (ELE). En concreto, se aplican de forma sistemática las tres pautas del principio de representación del DUA en el análisis de unidades didácticas sobre las emociones de 16 manuales de ELE de nivel B1. El análisis aborda de forma crítica las limitaciones presentes en estos materiales con un foco en tres factores clave en la representación de emociones: su delimitación, su visualización y su metalenguaje. La revisión de materiales se estructura en torno a las tres pautas del principio de representación y revela conexiones entre las carencias curriculares identificadas por estudios previos y los aportes del principio de representación. Las conclusiones de estudio contribuyen al creciente cuerpo de investigaciones sobre DUA en entornos de aprendizaje con diversos grados de competencia lingüística.
Pixel-by-pixel correction of beam hardening artifacts by bowtie filter in fan-beam CT
Authors: Ye Ping , Zhao Wei , Shimomura Taisei , Li Kai-Wen , Haga Akihiro , Geng Li-Sheng
Published: April 2024

Objective. Beam hardening (BH) artifacts in computed tomography (CT) images originate from the polychromatic nature of x-ray photons. In a CT system with a bowtie filter, residual BH artifacts remain when polynomial fits are used. These artifacts lead to worse visuals, reduced contrast, and inaccurate CT numbers. This work proposes a pixel-by-pixel correction (PPC) method to reduce the residual BH artifacts caused by a bowtie filter. Approach. The energy spectrum for each pixel at the detector after the photons pass through the bowtie filter was calculated. Then, the spectrum was filtered through a series of water slabs with different thicknesses. The polychromatic projection corresponding to the thickness of the water slab for each detector pixel could be obtained. Next, we carried out a water slab experiment with a mono energy E = 69 keV to get the monochromatic projection. The polychromatic and monochromatic projections were then fitted with a 2nd-order polynomial. The proposed method was evaluated on digital phantoms in a virtual CT system and phantoms in a real CT machine. Main results. In the case of a virtual CT system, the standard deviation of the line profile was reduced by 23.8%, 37.3%, and 14.3%, respectively, in the water phantom with different shapes. The difference of the linear attenuation coefficients (LAC) in the central and peripheral areas of an image was reduced from 0.010 to 0.003

cm

−
1

and 0.007

cm

−
1

to 0 in the biological tissue phantom and human phantom, respectively. The method was also validated using CT projection data obtained from Activion16 (Canon Medical Systems, Japan). The difference in the LAC in the central and peripheral areas can be reduced by a factor of two. Significance. The proposed PPC method can successfully remove the cupping artifacts in both virtual and authentic CT images. The scanned object’s shapes and materials do not affect the technique.
Electronic signal for mechanical failure in two-dimensional g-SiC
Authors: Li Jing , Shi Tan , Lu Chenyang , Peng Qing
Published: April 2024

It is non-trivial to identify mechanical failure using first-principles calculations as only long-wave phonons are used in these models due to size limitations. Here, we propose a new criterion to predict the mechanical failure by electronic bandgap closure in graphene-like two-dimensional silicon carbide (g-SiC) monolayer. The electronic bandgap decreases with strain and closes beyond the ultimate strain. This mechano-electronic coupling suggests that the onset of the zero bandgap and the correlation between electronic bandgap and ultimate strain could be used to predict the ideal mechanical failure of g-SiC monolayers.
Analysis of finite energy fresnel bessel beams scintillation level in turbulent communication links
Authors: Akcan Cemre Irem , Bayraktar Mert , Elmabruk Kholoud
Published: April 2024

Scintillation indices of Finite Energy Fresnel-Bessel Beams (FEFBBs) propagating for 6 Km in a turbulent atmosphere are analyzed. In this context, the effects of beam order and Gaussian beam waist on the reduction of scintillation level are evaluated. Both the point-like scintillation and the power scintillation indices are examined. The obtained results show that beam order does not have a significant impact on the scintillation levels. FEFBBs are able to reduce the power scintillation levels, then improve the system performance better than fundamental Gaussian beams. Thus, the provided results are significant for not only the performance improvement of the free-space optical (FSO) communication systems but also for the applications that require line of sight alignment namely directed infrared countermeasure (DIRCM).
Liénard type nonlinear oscillators and quantum solvability
Authors: V Chithiika Ruby , M Lakshmanan
Published: April 2024

Liénard-type nonlinear oscillators with linear and nonlinear damping terms exhibit diverse dynamical behavior in both the classical and quantum regimes. In this paper, we consider examples of various one-dimensional Liénard type-I and type-II oscillators. The associated Euler–Lagrange equations are divided into groups based on the characteristics of the damping and forcing terms. The Liénard type-I oscillators often display localized solutions, isochronous and non-isochronous oscillations and are also precisely solvable in quantum mechanics in general, where the ordering parameters play an important role. These include Mathews-Lakshmanan and Higgs oscillators. However, the classical solutions of some of the nonlinear oscillators are expressed in terms of elliptic functions and have been found to be quasi-exactly solvable in the quantum region. The three-dimensional generalizations of these classical systems add more degrees of freedom, which show complex dynamics. Their quantum equivalents are also explored in this article. The isotonic generalizations of the non-isochronous nonlinear oscillators have also been solved both classically and quantum mechanically to advance the studies. The modified Emden equation categorized as Liénard type-II exhibits isochronous oscillations at the classical level. This property makes it a valuable tool for studying the underlying nonlinear dynamics. The study on the quantum counterpart of the system provides a deeper understanding of the behavior in the quantum realm as a typical

P
T

-symmetric system.
Quantifying quantum entanglement via machine learning models
Authors: Feng Changchun , Chen Lin
Published: April 2024

Quantifying entanglement measures for quantum states with unknown density matrices is a challenging task. Machine learning offers a new perspective to address this problem. By training machine learning models using experimentally measurable data, we can predict the target entanglement measures. In this study, we compare various machine learning models and find that the linear regression and stack models perform better than others. We investigate the model’s impact on quantum states across different dimensions and find that higher-dimensional quantum states yield better results. Additionally, we investigate which measurable data has better predictive power for target entanglement measures. Using correlation analysis and principal component analysis, we demonstrate that quantum moments exhibit a stronger correlation with coherent information among these data features.
Pulsar Glitch Activities: The Spin Parameters Approach
Authors: Eya Innocent Okwudili , Iyida Evaristus Uzochukwu
Published: April 2024

Glitch activity refers to the mean increase in pulsar spin frequency per year due to rotational glitches. It is an important tool for studying super-nuclear matter using neutron star interiors as templates. Glitch events are typically observed in the spin frequency (ν) and frequency derivative (

ν

̇

) of pulsars. The rate of glitch recurrence decreases as the pulsar ages, and the activity parameter is usually measured by linear regression of cumulative glitches over a given period. This method is effective for pulsars with multiple regular glitch events. However, due to the scarcity of glitch events and the difficulty of monitoring all known pulsars, only a few have multiple records of glitch events. This limits the use of the activity parameter in studying neutron star interiors with multiple pulsars. In this study, we examined the relationship between the activity parameters and pulsar spin parameters (spin frequency, frequency derivative, and pulsar characteristic age). We found that a quadratic function provides a better fit for the relationship between activity parameters and spin parameters than the commonly used linear functions. Using this information, we were able to estimate the activity parameters of other pulsars that do not have records of glitches. Our analysis shows that the relationship between the estimated activity parameters and pulsar spin parameters is consistent with that of the observed activity parameters in the ensemble of pulsars.
A proposal for three categories of units within the SI
Authors: Lehman John , Migdall Alan , Scherschligt Julia , Whitehead Lorne
Published: April 2024

In this letter we examine the organization of the traditional base units and defining constants established in the 2019 redefinition of the international system of units (SI). For the next redefinition of the SI, which will accompany the anticipated redefinition of the second, we propose an organizational change to improve clarity while maintaining practicality. We propose three distinct categories of units: The first category comprises the four base-measurement units: The second, meter, kilogram, and ampere. The second contains physiologically-relevant derived units. The third category contains the remaining units derived from the base units.
Consistency assessment of latent heat flux and observational datasets over the Amazon basin
Authors: Miranda Vitor F V V , Jimenez J C , Dutra E , Trigo I F
Published: April 2024

The Amazon basin plays a crucial role in the global hydrological cycle and the climate system. Removal of latent heat from the surface covered by the tropical forest through evapotranspiration is a key process that still requires further research due to the complex nature of the involved processes, lack of observations and different model assumptions. Here we present an assessment of the consistency between different latent heat fluxes datasets through an indirect comparison against the daily amplitude of surface temperature and vegetation status estimated from satellite observations. Our study is based on the hypothesis that the observational satellite data can be used to provide hints on how realistically fluxes are represented in different datasets. Results evidence that datasets diverge inside the basin in both space and time, but it is possible to figure out areas under water-limited conditions, especially around the borders of the basin and some regions over eastern/southeastern Amazonia. In despite of these differences, a clear link between daily amplitude of surface temperature, leaf area index and latent heat flux can be observed over particular areas and seasons, where also correlations reach values closer to −0.98 (0.94) for surface temperature (leaf area index) indicating that satellite observations are suitable for assessing the representation of the partitioning of energy fluxes in models and widely used datasets.
Poisson–Lie analogues of spin Sutherland models revisited
Authors: Fehér L
Published: April 2024

Some generalizations of spin Sutherland models descend from ‘master integrable systems’ living on Heisenberg doubles of compact semisimple Lie groups. The master systems represent Poisson–Lie counterparts of the systems of free motion modeled on the respective cotangent bundles and their reduction relies on taking quotient with respect to a suitable conjugation action of the compact Lie group. We present an enhanced exposition of the reductions and prove rigorously for the first time that the reduced systems possess the property of degenerate integrability on the dense open subset of the Poisson quotient space corresponding to the principal orbit type for the pertinent group action. After restriction to a smaller dense open subset, degenerate integrability on the generic symplectic leaves is demonstrated as well. The paper also contains a novel description of the reduced Poisson structure and a careful elaboration of the scaling limit whereby our reduced systems turn into the spin Sutherland models.