bluuebunny/crossref_metadata_2025 huggingface dataset:
Walking Kinematic Coordination Becomes More In-Phase at Extreme Inclines
Authors: Gidley Alexis D. , Bailey Joshua P.
Published: September 2023

Previous research has shown that there are differences in mechanical energy, kinematics, and muscle activation when comparing walking on level and incline surfaces, especially on inclines above 15%. Muscle activations are significantly different while walking on extreme inclines, suggesting a different coordination pattern. We utilized continuous relative phase to assess walking kinematic coordination with respect to increased incline angles. Twelve healthy, college-aged individuals walked for 7 inclines of 1 minute each on a motorized treadmill at 3 mph at 0%, 5%, 10%, 15%, 20%, 25%, and 30% inclines. Kinematic data were collected during the last 20 seconds of each stage (120 Hz). Segmental and joint angles and angular velocities in the sagittal plane were calculated, from which continuous relative phase was determined for 3 joint couples: hip–knee, hip–ankle, and knee–ankle. There were significant differences in the coordination patterns during the first part of the contact phase in the hip–knee and hip–ankle couplings between the 0% and 30% inclines, with all 3 joint couplings becoming more in-phase at inclines above 15%. Importantly, the hip–knee coupling changed significantly from more out-of-phase to more in-phase between 10% and 15% incline. Shifting lower-extremity joint coordination in response to extreme inclines identifies potential coordinative strategies to achieve steep walking.
Moving Well-Being Well: Evaluating the Efficacy, Impact on Gender, and Role of Teacher Fidelity of a Fundamental Movement Skill-Based Intervention in Irish Primary School Children
Authors: Gavigan Nathan , Issartel Johann , Peers Cameron , Belton Sarahjane
Published: September 2023

Purpose: Competence in fundamental movement skills (FMS) is purported to be linked with increased physical activity participation. Yet, recent research suggests a low level of FMS proficiency in children. The aim of this study was to evaluate the efficacy, impact on gender, and influence of teacher fidelity on the Moving Well-Being Well intervention. Method: The intervention was delivered in 18 primary schools (n = 925, Mage = 7.55 years). Data were gathered on six FMS and two balance skills pre- and postintervention using the Test of Gross Motor Development—Third Edition and Bruininks–Oseretsky Test of Motor Proficiency 2. Results: The mean postintervention FMS score was higher than preintervention, with a mean increase of 7.85 (23%). A two-way analysis of covariance found gender was not statistically significant (p = .74), but teacher fidelity was statistically significant (p = .000; moderate effect size). Conclusions: The intervention significantly improved children’s FMS, having a similar effect on boys and girls. Teacher fidelity of implementation had a significant impact on FMS improvement.
Knowledge, Attitudes, and Behaviors Toward the Menstrual Cycle and Menstruation Among Elite African Women Football Players, Coaches, Health Personnel, and Referees
Authors: Mkumbuzi Nonhlanhla S. , Dlamini Senanile B. , Serner Andreas , Kryger Katrine Okholm , Brown Natalie , Larsen Brianna , Chibhabha Fidelis
Published: September 2023

Despite cross-cultural differences in knowledge and attitudes toward menstruation, most studies on menstruation in women’s sport have been conducted in high-income countries, such as in Europe, and none have been conducted in Africa. The aim of this study was to explore the knowledge, attitudes, and behaviors of African elite women football players, and their support personnel toward the menstrual cycle and menstruation. An anonymous questionnaire was distributed to all participants (n = 564) at two African women football tournaments. Ultimately, 238 women football players, 44 coaches, 18 health personnel, and 17 referees completed it. From 317 questionnaires analyzed, 17%, 27%, 56%, and 0% of players, coaches, health personnel, and referees, respectively, knew at least one menstrual cycle hormone; 91%, 95%, and 100% of players, coaches, and referees, respectively, did not know at least one menstrual cycle phase. Over 70% of health personnel believed that menstruation negatively affects women’s performance in sports compared with 36% of players; 18%, 28%, and 18% of players, health personnel, and referees, respectively, believed that, for convenience, the menstrual cycle should be changed by drugs like contraceptives; and 54%, 61%, 62%, and 40% of players, coaches, health personnel, and referees, respectively, were confident providing advice about the menstrual cycle to teammates. Minimal knowledge of the menstrual cycle has implications on the development of menstrual cycle considerate training environments and educational materials in African women’s football. Furthermore, the relatively low perceived effect of the menstrual cycle on sporting performance and belief in the use of contraceptives may be attributable to differences in community-level religiocultural and social contexts which influence menstrual experiences, and shape behavioral expectations.
Exercise-induced deep vein thrombosis in the subclavian vein in an elite female athlete
Authors: Blunt Jacqueline , Avila Laura , Temple Michael , Thornton Jane
Published: September 2023

An adolescent female presented to the emergency room with pain, swelling and a palpable lump in the right axilla following activity on a rowing ergometer. The differential diagnosis at the time of presentation was deep vein thrombosis, mass compression and cellulitis. An ultrasound scan revealed an occlusive thrombus of the right axillary and subclavian veins, basilic vein and proximal cephalic vein. The patient underwent pharmacomechanical thrombolysis followed by catheter-directed thrombolysis. Dynamic venogram testing revealed venous thoracic outlet syndrome (VTOS) and a transaxillary first rib resection was performed to decompress the costoclavicular space. Genetic testing revealed the patient was heterozygous for factor V Leiden. Two rounds of balloon dilatation plasty were performed to relieve recurring symptoms due to scarring and persisting compression, 1 and 3 years post rib resection. After extensive shared decision-making, the patient returned to sport, reporting only intermittent symptoms of post-thrombotic syndrome. This case sheds light on the importance of early diagnosis of VTOS for successful return to sport.
Ecological monitoring of physical activity, emotions and daily life activities in schizophrenia: the DiAPAson study
Authors: Zarbo Cristina , Rota Matteo , Calza Stefano , Crouter Scott E , Ekelund Ulf , Barlati Stefano , Bussi Riccardo , Clerici Massimo , Placenti Roberto , Paulillo Giuseppina , Pogliaghi Silvia , Rocchetti Matteo , Ruggeri Mirella , Starace Fabrizio , Zanolini Stefano , Zamparini Manuel , de Girolamo Giovanni
Published: September 2023

Background

Schizophrenia spectrum disorders (SSD) compromise psychosocial functioning, including daily time use, emotional expression and physical activity (PA).

Objective

We performed a cohort study aimed at investigating: (1) the differences in PA, daily activities and emotions between patients with SSD and healthy controls (HC); (2) the strength of the association between these variables and clinical features among patients with SSD.

Methods

Ninety-nine patients with SSD (53 residential patients, 46 outpatients) and 111 matched HC were assessed for several clinical variables, and levels of functioning by means of standardised clinical measures. Self-reported daily activities and emotions were assessed with a smartphone application for ecological momentary assessment (EMA), and PA levels were assessed with a wearable accelerometer for 7 consecutive days.

Findings

Patients with SSD, especially those living in residential facilities, spent more time being sedentary, and self-reported more sedentary and self-care activities, experiencing higher levels of negative emotions compared with HC. Moreover, higher functioning levels among patients were associated with more time spent in moderate-to-vigorous activity.

Conclusions

Sedentary behaviour and negative emotions are particularly critical among patients with SSD and are associated with more impaired clinical outcomes.

Clinical implications

Mobile-EMA and wearable sensors are useful for monitoring the daily life of patients with SSD and the level of PA. This population needs to be targeted with specific rehabilitative programmes aimed at improving their commitment to structured daily activities.
Indications of alcohol or drug use disorders in five different national registers in Sweden: a cross-sectional population-based study
Authors: Lundin Andreas , Danielsson Anna-Karin , Dalman Christina , Hollander Anna-Clara
Published: September 2023

Objective

The purpose of this study is to examine the prevalence of indications of alcohol or drug use disorders in five different national Swedish registers and to investigate the correlation between these registers. Furthermore, the intent is to investigate whether combining data from different registers increases the prevalence of these indications in the population due to the identification of different demographic groups in different registers.

Design

Cross-sectional study.

Setting and participants

Individuals living in Sweden aged 20–64 years in 2006, n=5 453 616.

Primary outcome

National registers included the Registers of Inpatient Care, Outpatient Care, Medications, Social Insurance and Convictions. Demographic variables were sex, age, migrant status, education and civil status. Indications of alcohol or drug use disorders were presented as prevalence in percentage (%), correlation was examined using phi correlation coefficients and differences across demographic factors were studied using logistic regression.

Results

The prevalence of an indication of alcohol or drug use disorder varied between registers, meaning that prevalence increased when all registers were considered together. The prevalence of alcohol use disorder increased by 60% and 66% among men and women, respectively, while the prevalence of drug use disorder increased by 45% and 80% among men and women, respectively, when all registers were combined, compared with only using the register with the highest prevalence. Registers contributed different indications of drug and alcohol use disorders.

Conclusions

Accurate estimates of alcohol or drug use disorders are critical for healthcare and rehabilitation. This study shows that using a single register alone underestimates the burden of disease unevenly, while combining a range of registers can provide a more accurate picture.
What women want if they were to have another baby: the Australian Birth Experience Study (BESt) cross-sectional national survey
Authors: Keedle Hazel , Lockwood Risharda , Keedle Warren , Susic Daniella , Dahlen Hannah G
Published: September 2023

Objectives

To explore if Australian women would do anything differently if they were to have another baby.

Design and setting

The Birth Experience Study (BESt) online survey explored pregnancy, birth and postnatal experiences for women who had given birth during 2016–2021 in Australia.

Participants

In 2021, 8804 women responded to the BESt survey and 6101 responses to the open text responses to the survey question ‘Would you do anything different if you were to have another baby?’ were analysed using inductive content analysis.

Results

A total of 6101 women provided comments in response to the open text question, resulting in 10 089 items of coding. Six categories were found: ‘Next time I'll be ready’ (3958, 39.2%) described how women reflected on their previous experience, feeling the need to better advocate for themselves in the future to receive the care or experience they wanted; ‘I want a specific birth experience’ (2872, 28.5%) and ‘I want a specific model of care’ (1796, 17.8%) highlighted the types of birth and health provider women would choose for their next pregnancy. ‘I want better access’ (294, 2.9%) identified financial and/or geographical constraints women experience trying to make choices for birth. Two categories included comments from women who said ‘I don’t want to change anything’ (1027, 10.2%) and ‘I don’t want another pregnancy’ (142, 1.4%). Most women birthed in hospital (82.9%) and had a vaginal birth (59.2%) and 26.7% had a caesarean.

Conclusion

Over 85% of comments left by women in Australia were related to making different decisions regarding their next birth choices. Most concerningly women often blamed themselves for not being more informed. Women realised the benefits of continuity of care with a midwife. Many women also desired a vaginal birth as well as better access to birthing at home.
Search for tri-nucleon decays of $$^{76}$$Ge in GERDA
Authors: Agostini M. , Alexander A. , Araujo G. , Bakalyarov A. M. , Balata M. , Barabanov I. , Baudis L. , Bauer C. , Belogurov S. , Bettini A. , Bezrukov L. , Biancacci V. , Bossio E. , Bothe V. , Brugnera R. , Caldwell A. , Calgaro S. , Cattadori C. , Chernogorov A. , Chiu P.-J. , Comellato T. , D’Andrea V. , Demidova E. V. , Di Giacinto A. , Di Marco N. , Doroshkevich E. , Fischer F. , Fomina M. , Gangapshev A. , Garfagnini A. , Gooch C. , Grabmayr P. , Gurentsov V. , Gusev K. , Hakenmüller J. , Hemmer S. , Hofmann W. , Hult M. , Inzhechik L. V. , Janicskó Csáthy J. , Jochum J. , Junker M. , Kazalov V. , Kermaïdic Y. , Khushbakht H. , Kihm T. , Kilgus K. , Kirpichnikov I. V. , Klimenko A. , Knöpfle K. T. , Kochetov O. , Kornoukhov V. N. , Krause P. , Kuzminov V. V. , Laubenstein M. , Lindner M. , Lippi I. , Lubashevskiy A. , Lubsandorzhiev B. , Lutter G. , Macolino C. , Majorovits B. , Maneschg W. , Manzanillas L. , Marshall G. , Misiaszek M. , Morella M. , Müller Y. , Nemchenok I. , Neuberger M. , Pandola L. , Pelczar K. , Pertoldi L. , Piseri P. , Pullia A. , Rauscher L. , Redchuk M. , Riboldi S. , Rumyantseva N. , Sada C. , Sailer S. , Salamida F. , Schönert S. , Schreiner J. , Schütt M. , Schütz A.-K. , Schulz O. , Schwarz M. , Schwingenheuer B. , Selivanenko O. , Shevchik E. , Shirchenko M. , Shtembari L. , Simgen H. , Smolnikov A. , Stukov D. , Sullivan S. , Vasenko A. A. , Veresnikova A. , Vignoli C. , von Sturm K. , Wester T. , Wiesinger C. , Wojcik M. , Yanovich E. , Zatschler B. , Zhitnikov I. , Zhukov S. V. , Zinatulina D. , Zschocke A. , Zsigmond A. J. , Zuber K. , Zuzel G. ,    GERDA collaboration
Published: September 2023

We search for tri-nucleon decays of $$^{76}$$

76

Ge in the dataset from the GERmanium Detector Array (GERDA) experiment. Decays that populate excited levels of the daughter nucleus above the threshold for particle emission lead to disintegration and are not considered. The ppp-, ppn-, and pnn-decays lead to $$^{73}$$

73

Cu, $$^{73}$$

73

Zn, and $$^{73}$$

73

Ga nuclei, respectively. These nuclei are unstable and eventually proceed by the beta decay of $$^{73}$$

73

Ga to $$^{73}$$

73

Ge (stable). We search for the $$^{73}$$

73

Ga decay exploiting the fact that it dominantly populates the 66.7 keV $$^{73m}$$

73
m

Ga state with half-life of 0.5 s. The nnn-decays of $$^{76}$$

76

Ge that proceed via $$^{73m}$$

73
m

Ge are also included in our analysis. We find no signal candidate and place a limit on the sum of the decay widths of the inclusive tri-nucleon decays that corresponds to a lower lifetime limit of 1.2$$\times $$
×
10$$^{26}$$

26

 yr  (90% credible interval). This result improves previous limits for tri-nucleon decays by one to three orders of magnitude.
Excited-state dynamics of deuterated indigo
Authors: Cohen Trevor , Svadlenak Nathan , Smith Charles , Vo Krystal , Lee Si-Young , Parejo-Vidal Ana , Kincaid Joseph R. A. , Sobolewski Andrzej L. , Rode Michal F. , de Vries Mattanjah S.
Published: September 2023

Indigo, a rich blue dye, is an incredibly photostable molecule that has survived in ancient art for centuries. It is also unique in that it can undergo both an excited-state hydrogen and proton transfer on the picosecond timescale followed by a ground-state back transfer. Previously, we performed gas phase excited-state lifetime studies on indigo to study these processes in a solvent-free environment, combined with excited-state calculations. We found two decay pathways, a fast sub-nanosecond decay and a slow decay on the order of 10 ns. Calculations of the excited-state potential energy surface found that both hydrogen and proton transfer are nearly isoenergetic separated by a 0.1 eV barrier. To further elucidate these dynamics, we now report a study with deuterated indigo, using resonance-enhanced multi-photon ionization and pump-probe spectroscopy with mass spectrometric isotopomer selection. From new calculations of the excited-state potential energy surface, we find sequential double-proton or hydrogen transfer, whereby the trajectory to the second transfer passes a second barrier and then encounters a conical intersection that leads back to the ground state. We find that deuteration only increases the excited-state lifetimes of the fast decay channel, suggesting tunneling through the first barrier, while the slower channel is not affected and may involve a different intermediate state.

Graphical abstract
Bifurcations of Mode-Locked Periodic Orbits in Three-Dimensional Maps
Authors: Muni Sishu Shankar , Banerjee Soumitro
Published: September 2023

In this paper, we report the bifurcations of mode-locked periodic orbits occurring in maps of three or higher dimensions. The “torus” is represented by a closed loop in discrete time, which contains stable and unstable cycles of the same periodicity, and the unstable manifolds of the saddle. We investigate two types of “doubling” of such loops: (a) two disjoint loops are created and the iterates toggle between them, and (b) the length of the closed invariant curve is doubled. Our work supports the conjecture of Gardini and Sushko, which says that the type of bifurcation depends on the sign of the third eigenvalue. We also report the situation arising out of Neimark–Sacker bifurcation of the stable and saddle cycles, which creates cyclic closed invariant curves. We show interesting types of saddle-node connection structures, which emerge for parameter values where the stable fixed point has bifurcated but the saddle has not, and vice versa.
Convergence of Discrete-Time Cellular Neural Networks with Application to Image Processing
Authors: Di Marco Mauro , Forti Mauro , Pancioni Luca , Tesi Alberto
Published: September 2023

The paper considers a class of discrete-time cellular neural networks (DT-CNNs) obtained by applying Euler’s discretization scheme to standard CNNs. Let [Formula: see text] be the DT-CNN interconnection matrix which is defined by the feedback cloning template. The paper shows that a DT-CNN is convergent, i.e. each solution tends to an equilibrium point, when [Formula: see text] is symmetric and, in the case where [Formula: see text] is not positive-semidefinite, the step size of Euler’s discretization scheme does not exceed a given bound ([Formula: see text] is the [Formula: see text] unit matrix). It is shown that two relevant properties hold as a consequence of the local and space-invariant interconnecting structure of a DT-CNN, namely: (1) the bound on the step size can be easily estimated via the elements of the DT-CNN feedback cloning template only; (2) the bound is independent of the DT-CNN dimension. These two properties make DT-CNNs very effective in view of computer simulations and for the practical applications to high-dimensional processing tasks. The obtained results are proved via Lyapunov approach and LaSalle’s Invariance Principle in combination with some fundamental inequalities enjoyed by the projection operator on a convex set. The results are compared with previous ones in the literature on the convergence of DT-CNNs and also with those obtained for different neural network models as the Brain-State-in-a-Box model. Finally, the results on convergence are illustrated via the application to some relevant 2D and 1D DT-CNNs for image processing tasks.
Similar Master Stability Functions for Different Coupling Schemes in Basic Chaotic Systems
Authors: Dayani Zahra , Parastesh Fatemeh , Jafari Sajad , Schöll Eckehard , Kurths Jürgen , Sprott Julien Clinton
Published: September 2023

Synchronization is a prominent phenomenon in coupled chaotic systems. The master stability function (MSF) is an approach that offers the prerequisites for the stability of complete synchronization, which is dependent on the coupling configuration. In this paper, some basic chaotic systems with the general form of the Sprott-A, Sprott-B, Sprott-D, Sprott-F, Sprott-G, Sprott-O, and Jerk systems are considered. For each system, their parametric form is designed, and constraints required to have similar MSFs in different coupling schemes are determined. Then, the parameters of the designed chaotic systems are found through an exhaustive computer search seeking chaotic solutions. The simplest cases found in this way are introduced, and similar synchronization patterns are confirmed numerically.
Crossing Limit Cycles Bifurcating from Two or Three Period Annuli in Discontinuous Planar Piecewise Linear Hamiltonian Differential Systems with Three Zones
Authors: Braga Denis de Carvalho , Fonseca Alexander Fernandes da , Mello Luis Fernando , Ribeiro Ronisio Moises , Pessoa Claudio Gomes
Published: September 2023

The main topic studied in this article is the number of crossing limit cycles bifurcating from two or three period annuli in discontinuous planar piecewise linear Hamiltonian differential systems with three zones. With regard to the studies already published in the literature on this subject, we highlight the following five aspects of our work: (1) the expressions of the first order Melnikov functions for suitable perturbations of a piecewise Hamiltonian system with three zones separated by two parallel lines are obtained explicitly; (2) the way the Melnikov functions are obtained is different from what has already been done for similar studies; (3) the expressions of the Melnikov functions are used to estimate the number of crossing limit cycles that bifurcate simultaneously from period annuli under suitable polynomial perturbations; (4) since the piecewise Hamiltonian system studied here has no symmetry, the number of crossing limit cycles bifurcating from the period annuli is greater than or equal to those obtained in systems already studied; (5) unlike other similar studies, we present a concrete example of a piecewise linear near-Hamiltonian differential system in which the lower bound of the number of limit cycles that bifurcate from the period annuli is reached.
Microscopic study of normal deformed bands in 167,169,171Lu
Authors: Faisal Mohd , Devi Rani , Khosa S. K. , Bhat G. H. , Sheikh J. A.
Published: September 2023

The normal deformed bands of [Formula: see text]Lu isotopes have been studied by using projected shell model approach. The band head spins, configurations and energies of all the normal deformed bands are reproduced well by the above said approach. The present calculations have predicted [Formula: see text] band head spin for [523]7/2− bands of [Formula: see text]Lu. The observed systematics of aligned angular momenta and the experimental differences in frequencies around the backbends for all the normal deformed bands are reproduced well by the theoretical results. Besides this, the observed backbends or upbends in these isotopes may be ascribed to the alignment of a pair of neutrons in the neutron [Formula: see text] orbital. Although the theoretical [Formula: see text] values obtained from the projected shell model wavefunctions overestimate the experimental [Formula: see text] values in [Formula: see text]Lu, yet they are close to the measured values, considering the precision of measurement. The reduction in the theoretical [Formula: see text] values around the band crossing region may be ascribed to change in nuclear structure of yrast bands due to neutron pair alignment in [Formula: see text] orbital.
Active Vibration Control of Truncated Conical Porous Smart Composite Shells
Authors: Ebrahimi Farzad , Mollazeinal Ali , Ahari Mehrdad Farajzadeh
Published: September 2023

The current investigation examines the vibrational properties of porous truncated conical structures made from a composite material consisting of polyvinylidene fluoride (PVDF) reinforced with Terfenol-D particles. The effective properties of the magneto-electro-elastic composite were determined using the Eshelby–Mori–Tanaka model. The governing equation of the system is obtained by applying the principles of minimal potential energy and Hamilton’s principle to the first-order shear deformation theory. The equations are solved utilizing the generalized differential quadrature technique. This study aims to examine the interconnections among the volume percentage, vertex angle, shell length, boundary conditions, and porosity of Terfenol-D. Moreover, to validate the results, a comprehensive analysis was performed by comparing them with the existing body of literature, resulting in a favorable and accurate agreement. The results demonstrate a consistent decrease in the linear natural frequency as the vertex angle gradually increases. The findings derived from this study have the potential to serve as a reference point for future analyses.
Dynamic Analysis of Sandwich Magnetostrictive Nanoplates with a Mass–Spring–Damper Stimulator
Authors: Ebrahimi Farzad , Ahari Mehrdad Farajzadeh
Published: September 2023

This study aims to examine the dynamic characteristics of a sandwich composite nanoplate when exposed to a nano damper–spring–mass stimulator. The composite structure consists of a core layer composed of magnetostrictive material, accompanied by upper and lower facesheets made of functionally graded material (FGM). Moreover, the proposed framework is designed to be based on a visco-Pasternak medium. The governing equations of nanoplates are derived using the higher-order shear deformation theory (HSDT) and Hamilton’s principle. In the end, Navier’s solution is utilized to solve partial differential equations, while the Laplace transform is employed for solving ordinary differential equations. Subsequently, a thorough investigation is conducted with a primary focus on examining the impact of different parameters on the dynamic response of the continuous system. The findings indicate that the incorporation of the damper–spring–mass system into the nanoplate has a notable impact on its natural frequency. The results can serve as reference points for the effective development of nanosensors, nanoresonators, drug delivery systems, and biosensors.
Properties of multihomogeneous spaces and relation with T-varieties
Authors: Mallick Vivek Mohan , Roy Kartik
Published: September 2023

We study multihomogeneous spaces corresponding to [Formula: see text]-graded algebras over an algebraically closed field of characteristic [Formula: see text] and their relation with the description of [Formula: see text]-varieties.
Strongly π-regular elements and Drazin inverses
Authors: Rani Goyal Dimple , Khurana Anjana , Khurana Dinesh
Published: September 2023

We find an expression for the Drazin inverse of a strongly [Formula: see text]-regular element [Formula: see text] in the form [Formula: see text] when [Formula: see text] for some nonnegative integer [Formula: see text] and positive integer [Formula: see text]. This extends the result by Azumaya, which is the case when [Formula: see text] and [Formula: see text], and a result by Drazin, which is the case when [Formula: see text] is arbitrary and [Formula: see text]. We give new proofs of several results in the literature. For instance, we give an easy proof of the result that for two commuting Drazin invertible elements [Formula: see text], [Formula: see text] of [Formula: see text], then [Formula: see text] is Drazin invertible if and only if so is [Formula: see text], where [Formula: see text] is the Drazin inverse of [Formula: see text]. Our proof is akin to the case when [Formula: see text] and [Formula: see text] are invertible.
Relatively polyform modules
Authors: Zhang Xiaoxiang , Lee Gangyong , Tung Nguyen Khanh
Published: September 2023

In this paper, we investigate polyform modules and introduce the notion of relatively polyform modules over a ring [Formula: see text]. Some new characterizations and properties of polyform modules are obtained. For a retractable polyform module [Formula: see text], it is proved that the maximal right ring of quotients of End[Formula: see text] is End[Formula: see text], where [Formula: see text] is the rational hull of [Formula: see text]. Moreover, we characterize nonsingular modules by using the relatively polyform property. In addition, it is proved that the class of all polyform right [Formula: see text]-modules is closed under submodules and rational extensions.
Generating symmetric and alternating groups
Authors: Catoiu Stefan , Diaconescu Răzvan
Published: September 2023

We provide three generalizations of all best known generating sets for [Formula: see text] and [Formula: see text]: (1) [Formula: see text]-cycles with consecutive entries; (2) [Formula: see text]-cycles with fixed first [Formula: see text] entries; (3) two cycles, either [Formula: see text] or [Formula: see text]. Our work on (3) fills a gap in the history of the problem, going back to a 1939 paper by S. Piccard [Sur les bases du groupe symétrique et du groupe alternant, Math. Ann. 116(1) (1939) 752–767].
Error-insensitive preparation of entangled states between a Josephson qubit and microwave photons via invariant-based shortcuts
Authors: Yan Run-Ying , Lu Xiao-Jing , Li Ming , Dong Xin-Ping , Yang Fei , Feng Zhi-Bo
Published: September 2023

Optimal preparation of quantum entanglement is of significance to information processing and state engineering. In this paper, an efficient scheme is proposed to implement error-insensitive generation of entangled states between a Josephson qubit and microwave photons by the technique of invariant-based shortcuts to adiabaticity. A superconducting qubit is dispersively coupled to a quantized cavity field of one-dimensional transmission line resonator. Within a considered subspace spanned by three composite states, we deal with an effective interaction of the composite system with two classical drivings. A maximally entangled qubit-photon state can be deterministically induced using a splitting-like quantum state transfer. To nullify the deviation errors of Rabi coupling and frequency detuning, we optimize the driving parameters and then make the entanglement creation insusceptible to these control imperfections. Thanks to the mitigation of deviation effects, robustness against the residual noisy environment could be obtained numerically. The proposed strategy could provide a promising avenue towards fast and robust information processing with superconducting circuit quantum electrodynamics.
Cosmology in the Lorentz gauge theory
Authors: Koivisto Tomi
Published: September 2023

This proceeding is an introduction to cosmological applications of the Lorentz gauge theory. It provides the ingredients for a unique, though yet tentative [Formula: see text]CDM theory of cosmology. Emergence of spacetime is described by the spontaneous symmetry breaking called here the khronogenesis. Space is then associated with the field strength of the antiself-dual gauge potential, and gravity is associated with the self-dual field strength. In the cosmological setting, khronogenesis seems to predict inflation. It is shown that the Lorentz gauge theory allows the consistent description of spin currents which could have important roles in cosmological phenomenology.
Chronological-safe kind of geometric phase for C60 fullerenes in Gödel space–times
Authors: Cavalcante Everton , Spinelly Jean
Published: September 2023

In this paper, we investigate a rotating fullerene molecule with Ih symmetry within the framework of non-inertial space-times. We use a low-energy geometric theory to describe the molecule as a two-dimensional spherical space of Gödel type. Using the well-known fictitious ’t Hooft–Polyakov monopole to decouple the doublet associated with the lattice, we employ the Dirac factor method to derive a geometric phase for the fermions in the system. We also discuss the chronology protection feature of the phase through specific geometric considerations for the system.
Investigating the Tear Fracture of Elastomeric Skins in Morphing Wings: An Experimental and Computational Study
Authors: Gour Sankalp , Ahmad Dilshad , Kumar Deepak , Ajaj Rafic M. , Zweiri Yahya
Published: September 2023

Morphing wings covered with elastomeric skin have emerged as a promising technique for enhancing the performance and efficiency of unmanned aerial vehicles (UAVs). These morphing wings can change shape in flight, enabling UAVs to adapt to evolving aerodynamic conditions, fly more efficiently, maneuver more effectively and perform a broader range of missions. The durability of such elastomeric skins that cover the wings, on the other hand, is a critical issue that requires careful consideration. During the flight, elastomeric skins are subjected to a variety of mechanical stresses, including tear and fracture, which can significantly impact the performance and reliability of elastomeric morphing wings. To ensure the long-term durability of the morphing wings, a comprehensive understanding of the tear fracture of elastomeric skins is essential. This study employs a multi-faceted approach of experimental and computational research to investigate the tear fracture of elastomeric skins in morphing wings. Initially, the fracture properties of three materials — Latex, Oppo and Ecoflex — are evaluated experimentally for various cut positions. Subsequently, a continuum physics-based tear fracture model is derived to numerically simulate the mechanical behavior of elastomeric skins. The Griffith criterion, a well-established method, is adopted to investigate mode-III fracture tests, specifically the trousers test, which involves pulling two legs of a cut specimen horizontally apart. Finally, the derived tear fracture model is validated by comparing model solutions to tear test data obtained experimentally. The study suggests that adjusting the stretch ratio and cut position can significantly impact the stress distribution of elastomeric skins, the ability to resist fracture and the stretching behavior of elastomeric morphing wings.
Dynamical analysis of a Lotka–Volterra competition model with both Allee and fear effects
Authors: Chen Shangming , Chen Fengde , Srivastava Vaibhava , Parshad Rana D.
Published: September 2023

Population ecology theory is replete with density-dependent processes. However, trait-mediated or behavioral indirect interactions can both reinforce or oppose density-dependent effects. This paper presents the first two species competitive ODE and PDE systems, where the non-consumptive behavioral fear effect and the Allee effect, a density-dependent process, are both present. The stability of the equilibria is discussed analytically using the qualitative theory of ordinary differential equations. It is found that the Allee effect and the fear effect change the extinction dynamics of the system and the number of positive equilibrium points, but they do not affect the stability of the positive equilibria. We also observe standard co-dimension one bifurcation in the system by varying the Allee or fear parameter. Interestingly, we find that the Allee effect working in conjunction with the fear effect can bring about several dynamical changes to the system with only fear. There are three parametric regimes of interest in the fear parameter. For small and intermediate amounts of fear, the Allee + fear effect opposes dynamics driven by the fear effect. However, for large amounts of fear the Allee + fear effect reinforces the dynamics driven by the fear effect. The analysis of the corresponding spatially explicit model is also presented. To this end, the comparison principle for parabolic PDE is used. The conclusions of this paper have strong implications for conservation biology, biological control as well as the preservation of biodiversity.
Stability and spatially inhomogeneous patterns induced by nonlocal prey competition in a generalist predator–prey system
Authors: Xue Shuyang , Yang Feng , Song Yongli
Published: September 2023

In this paper, we investigate the influence of the nonlocal prey competition on the spatio-temporal dynamics for a generalist predator–prey system. The condition of stability and bifurcations is clearly determined. Our results show that when the prey spreads quickly, the nonlocal intraspecific competition of the prey does not affect the dynamics, however, when the prey spreads slowly, it can affect the dynamics. Besides, no Hopf bifurcation occurs if the ratio of the growth rate of the predator to prey is larger, otherwise, system has Hopf bifurcation and Hopf Bogdanov–Takens bifurcation and so on. It is surprised that the system only with the nonlocal prey competition has more rich dynamics than the system with the nonlocal competitions in both the prey and the predator. The coexistence of bistable spatially inhomogeneous steady states is also found.
Investigation of lead-free BiFeO3–BaTiO3 piezoelectric ceramics through precise composition control
Authors: Qin Hailan , Zhao Jianwei , Chen Xiaoxin , Li Hongtian , Wang Shenghao , Du Yuxiao , Li Peifeng , Zhou Huanfu , Wang Dawei
Published: September 2023

BiFeO3–BaTiO3 is a promising lead-free piezoelectric ceramic, exhibiting high Curie temperature and superior electrochemical characteristics. In this work, [Formula: see text]BiFeO3–xBaTiO3 (BF–xBT, [Formula: see text], 0.28, 0.30, 0.32, 0.34, 0.36) ceramics were fabricated using the conventional solid-state reaction method through precise composition control. Multiple characterization techniques, including X-ray powder diffraction (XRD), scanning electron microscope (SEM), and electrical property testing systems, were applied to systematically examine the crystallographic structure, microstructure, as well as the dielectric, ferroelectric and piezoelectric properties of the BF–xBT ceramics. The XRD results confirm that all compositions exhibit a typical perovskite structure, transitioning from a single rhombohedral phase to a rhombohedral–cubic phase mixture as the BT content increases. SEM shows apparent core–shell microstructures in the ceramics. Notably, the results demonstrated that the BF–0.30BT ceramic exhibits the maximum piezoelectric constant ([Formula: see text]) [Formula: see text][Formula: see text]pC/N, while the BF–0.34BT ceramic displays the maximum converse piezoelectric constant [Formula: see text][Formula: see text]pm/V, which highlights the suitability of BF–BT ceramics for high-performance piezoelectric applications.
Prediction model for properties of hot-rolled steel strip: An ICME approach
Authors: Chakraborty Subhamita , Chattopadhyay Partha Protim , Kumaran D. , Datta Shubhabrata
Published: September 2023

The Integrated Computational Materials Engineering (ICME) approach is implemented to develop an integrated model for the processing of steel at a hot strip mill. The effect of temperature, deformation, and subsequent cooling rate on microstructure and its associated properties of the steel are mapped using analytical, numerical as well as machine learning approaches, all applied in tandem. The modeling approaches include a rigid visco-plastic approach for the flow formulation, finite volume method to calculate temperature distribution profile, artificial neural network (ANN) modeling for predicting CCT diagram, and Mecking–Kock model along with stress mixing law for the structure–property correlation. The composite model for mapping the final microstructure and microstructure-dependent properties of the steel, which depends on the composition, and various parameters of the hot strip mill is validated through a comparison of predicted values with the published results. The work shows that the hybridization of constitutive equations with the data-driven approach in ICME can successfully model a complex system like the hot strip mill.
Stoneley waves in isotropic crustal rocks under the theory of generalized thermoelastic diffusion
Authors: Debnath Sanjay , Singh S. S. , Othman Mohamed I. A.
Published: September 2023

This paper investigates the propagation of Stoneley waves through bonded and unbonded interfaces between two dissimilar homogeneous transversely isotropic generalized thermo-elastic diffusion rocks. The governing equations for the current problem are obtained and are solved to determine the characteristic polynomial equations for both mediums in terms of penetration depth. These equations are solved using Ferrari’s approach, and the variation in penetration depths with angular frequency and wavenumber is shown. The secular equations of the Stoneley waves are developed using proper boundary conditions and these equations have been solved numerically to determine the phase velocity and attenuation coefficients. We have discovered three modes of the Stoneley waves in thermo-diffusive crustal rocks. We have confirmed that the paths of particle motion for Stoneley waves are elliptic in nature. Some known results [Kumar et al. [2017] “Mathematical modeling of Stoneley wave in a transversely isotropic thermoelastic media”, Applications and Applied Mathematics 12(1), 319–336; Kumar and Kansal [2008b] “Propagation of Rayleigh waves on free surface of transversely isotropic generalized thermoelastic diffusion”, Applied Mathematics and Mechanics29(11), 1451–1462] are recovered from this analysis to validate our investigation.
Discount or Speed?: An Analysis of Reward Offer in Exchange for No-Rush Shipping
Authors: Issarathipya Pavarit , Amornpetchkul Thunyarat Bam
Published: September 2023

This research investigates how a no-rush shipping reward program, which offers a discount or a reward to a customer who chooses no-rush shipping for her online purchased items, can be utilized by an online seller to reduce shipping and expediting costs. In particular, we consider a setting in which an online seller has to ship two items to a customer. Each item can be shipped either on time or late, depending on its uncertain lead time. If an item is delivered late, the seller will incur a loss in customer goodwill unless the customer opts in to a no-rush shipping reward program and agrees to take a reward in exchange for potentially receiving an item late. To avoid shipping an item late, the seller also has an option to expedite an item at an extra cost. The seller’s optimal decisions regarding whether to offer a no-rush shipping reward program on any items and whether to ship each item separately or together at a normal or expedited speed are characterized. Our findings reveal that the number of items that the seller should offer the no-rush shipping reward program decreases as the required reward to entice customer participation increases. If the no-rush shipping reward program is offered on both items, then consolidating them into a single shipment always emerges as the optimal strategy. However, in cases where the program applies to none or only one item, it would be optimal for the seller to consolidate the shipment if and only if the shipping cost is sufficiently large. Through numerical demonstration, we underscore the noteworthy cost savings attainable via the no-rush shipping reward program, especially when the expected wait time to receive an item is long, the expediting cost is large, but the normal shipping cost is small. This study suggests that implementing a no-rush shipping reward program empowers online sellers with enhanced shipping management flexibility, which in turn effectively reduces operating and shipping costs as well as the environmental impact, while also meeting customers’ expectation.
A Boundary Element Method for Acoustic Problems in Relative Motion Between Source and Fluid
Authors: Sun Ruihua , Wu Haijun , Jiang Weikang , Ji Liang , Li Danwang
Published: September 2023

To calculate the acoustic problems of relative uniform motion between the acoustic source and the fluid, we propose a boundary element method (BEM) strategy that can calculate various forms of relative uniform motion in subsonic conditions in a unified framework and is simple to implement. The acceleration algorithm for the BEM, like the fast multipole method (FMM), in the relative motionless state between the source and the fluid can be directly used without major modifications to the program. We propose a two-step transformation method to unify the wave equations of different relative motion forms into the classical form. In the first step, we transform the wave equations for various forms of relative motion into the equation where the convective terms are present only in the source part. Then, in the second step, we propose an acoustic-analogy Lorentz (a-a Lorentz) transformation to apply Lorentz covariance further to eliminate the convection term and establish the wave equation with classical form in a-a Lorentz space. We implement the boundary integration in the transformed a-a Lorentz space and derive a transformation method to transform discretized geometry and boundary conditions in the original space to the a-a Lorentz space. The problem that the boundary conditions are difficult to apply when solving the boundary integral equation (BIE) after the time-space coordinate transformation is solved. Numerical validations for the proposed method are performed by comparing with analytical results over a wide range of relative velocities. The results show that the proposed method can efficiently compute such problems with high accuracy and concise formulation.
Human–machine Teaming with Small Unmanned Aerial Systems in a MAPE-K Environment
Authors: Cleland-Huang Jane , Chambers Theodore , Zudaire Sebastian , Chowdhury Muhammed Tawfiq , Agrawal Ankit , Vierhauser Michael
Published: September 2023

The Human Machine Teaming (HMT) paradigm focuses on supporting partnerships between humans and autonomous machines. HMT describes requirements for transparency, augmented cognition, and coordination that enable far richer partnerships than those found in typical human-on-the-loop and human-in-the-loop systems. Autonomous, self-adaptive systems in domains such as autonomous driving, robotics, and Cyber-Physical Systems, are often implemented using the MAPE-K feedback loop as the primary reference model. However, while MAPE-K enables fully autonomous behavior, it does not explicitly address the interactions that occur between humans and autonomous machines as intended by HMT. In this article, we, therefore, present the

MAPE-K
HMT

framework, which utilizes runtime models to augment the monitoring, analysis, planning, and execution phases of the MAPE-K loop to support HMT despite the different operational cadences of humans and machines. We draw on examples from our own emergency response system of interactive, autonomous, small unmanned aerial systems to illustrate the application of

MAPE-K
HMT

in both a simulated and physical environment, and we discuss how the various HMT models are connected and can be integrated into a MAPE-K solution.