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1,063 results on '"Thomas, Jack"'

1. Nearsightedness in Materials with Indirect Band Gap

Author

Chen, Huajie, Feng, Juerong, Ortner, Christoph, and Thomas, Jack

Subjects
Mathematical Physics, 74E15, 81V45, 81V70
Abstract

We investigate the nearsightedness property in the linear tight binding model at zero Fermi-temperature. We focus on the decay property of the density matrix for materials with indirect band gaps. By representing the density matrix in reciprocal space, we establish a qualitatively sharp estimate for the exponential decay rate in homogeneous systems. An extending result under perturbations is also derived. This work refines the estimates presented in (Ortner, Thomas & Chen 2020), particularly for systems with small band gaps.

Published
2025

2. $(\lambda,\lambda)$-eigenfunctions on compact manifolds

Author

Munn, Thomas Jack and Riedler, Oskar

Subjects
Mathematics - Differential Geometry, 53C35, 53C43, 58E20
Abstract

In this note we study $(\lambda,\mu)$-eigenfamilies on compact Riemannian manifolds when $\lambda = \mu$. We show that any compact manifold admitting a $(\lambda,\lambda)$-eigenfunction is a mapping torus and that any $(\lambda,\lambda)$-eigenfamily is one dimensional. Additionally, we consider generalised eigenfamilies, which can have higher dimension, and relate these to harmonic Riemannian submersions to a torus., Comment: 10 pages, comments welcome

Published
2024

3. Self-consistent Coulomb interactions for machine learning interatomic potentials

Author

Thomas, Jack, Baldwin, William J., Csányi, Gábor, and Ortner, Christoph

Subjects
Physics - Computational Physics, Condensed Matter - Materials Science, 65E05, 74E15, 81V45, 81V70
Abstract

A ubiquitous approach to obtain transferable machine learning-based models of potential energy surfaces for atomistic systems is to decompose the total energy into a sum of local atom-centred contributions. However, in many systems non-negligible long-range electrostatic effects must be taken into account as well. We introduce a general mathematical framework to study how such long-range effects can be included in a way that (i) allows charge equilibration and (ii) retains the locality of the learnable atom-centred contributions to ensure transferability. Our results give partial explanations for the success of existing machine learned potentials that include equilibriation and provide perspectives how to design such schemes in a systematic way. To complement the rigorous theoretical results, we describe a practical scheme for fitting the energy and electron density of water clusters., Comment: 33 pages, 1 figure

Published
2024

4. NAVIGATING PATHWAYS TO SUCCESS: LESSONS FROM A JOURNEY THROUGH HIGHER EDUCATION LEADERSHIP

Author

Thomas, Jack

Subjects
Company business management, Market trend/market analysis, Education, Higher -- Demographic aspects -- International aspects, Social movements -- Forecasts and trends, Leadership -- Personal narratives, Universities and colleges -- Management -- United States
Abstract

As I reflect on my journey through higher education, I find myself looking back on a career that began in the small, rural community of Calhoun in Lowndes County, Alabama. [...]

Published
2024

5. Harmonic Morphisms on Lie groups and Minimal Conformal Foliations of Codimension two

Author

Gudmundsson, Sigmundur and Munn, Thomas Jack

Subjects
Mathematics - Differential Geometry, 53C35, 53C43, 58E20
Abstract

Let G be a Lie group equipped with a left-invariant semi-Riemannian metric. Let K be a semisimple subgroup of G generating a left-invariant conformal foliation F of codimension two on G. We then show that the foliation F is minimal. This means that locally the leaves of F are fibres of a complex-valued harmonic morphism. In the Riemannian case, we prove that if the metric restricted to K is biinvariant then F is totally geodesic.

Published
2023

6. Minimal Submanifolds via Complex-Valued Eigenfunctions

Author

Gudmundsson, Sigmundur and Munn, Thomas Jack

Subjects
Mathematics - Differential Geometry, 53C35, 53C43, 58E20
Abstract

In this work we introduce a new method for manufacturing minimal submanifolds in Riemannian geometry. For this we employ the so called complex-valued eigenfunctions. This is particularly interesting in the cases when the Riemannian ambient manifold is compact.

Published
2023

9. Polynomial Approximation of Symmetric Functions

Author

Bachmayr, Markus, Dusson, Geneviève, Ortner, Christoph, and Thomas, Jack

Subjects
Mathematics - Numerical Analysis
Abstract

We study the polynomial approximation of symmetric multivariate functions and of multi-set functions. Specifically, we consider $f(x_1, \dots, x_N)$, where $x_i \in \mathbb{R}^d$, and $f$ is invariant under permutations of its $N$ arguments. We demonstrate how these symmetries can be exploited to improve the cost versus error ratio in a polynomial approximation of the function $f$, and in particular study the dependence of that ratio on $d, N$ and the polynomial degree. These results are then used to construct approximations and prove approximation rates for functions defined on multi-sets where $N$ becomes a parameter of the input.

Published
2021

10. Rigorous body-order approximations of an electronic structure potential energy landscape

Author

Thomas, Jack, Chen, Huajie, and Ortner, Christoph

Subjects
Mathematical Physics, 65E05, 74E15, 81V45, 81V70
Abstract

We show that the local density of states (LDOS) of a wide class of tight-binding models has a weak body-order expansion. Specifically, we prove that the resulting body-order expansion for analytic observables such as the electron density or the energy has an exponential rate of convergence both at finite Fermi-temperature as well as for insulators at zero Fermi-temperature. We discuss potential consequences of this observation for modelling the potential energy landscape, as well as for solving the electronic structure problem.

Published
2021
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11. Locality of Interatomic Interactions in Self-Consistent Tight Binding Models

Author

Thomas, Jack

Subjects
Mathematical Physics, 74E15, 81V45
Abstract

A key starting assumption in many classical interatomic potential models for materials is a site energy decomposition of the potential energy surface into contributions that only depend on a small neighbourhood. Under a natural stability condition, we construct such a spatial decomposition for self-consistent tight binding models, extending recent results for linear tight binding models to the non-linear setting., Comment: 15 pages

Published
2020
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12. Point Defects in Tight Binding Models for Insulators

Author

Ortner, Christoph and Thomas, Jack

Subjects
Mathematical Physics, 65N12, 65N25, 74E15, 74G65, 81V45
Abstract

We consider atomistic geometry relaxation in the context of linear tight binding models for point defects. A limiting model as Fermi-temperature is sent to zero is formulated, and an exponential rate of convergence for the nuclei configuration is established. We also formulate the thermodynamic limit model at zero Fermi-temperature, extending the results of [H. Chen, J. Lu, C. Ortner. Arch. Ration. Mech. Anal., 2018]. We discuss the non-trivial relationship between taking zero temperature and thermodynamic limits in the finite Fermi-temperature models., Comment: 38 pages, 4 figures

Published
2020

15. Analysis of an ab initio potential energy landscape

Author

Thomas, Jack

Subjects
QA Mathematics, QC Physics
Abstract

A wide range of electronic, optical and magnetic properties of solids are determined by electronic structure. Computational methods, such as density functional theory, have been used successfully to model electronic structure and thus allowed the investigation and prediction of properties of materials. However, even now, the high computational cost of these ab initio methods severely limits their applicability in material modelling to thousands of atoms for static and hundreds of atoms for long-time dynamic simulations. In modelling tasks involving only the mechanics of the atoms, one may bypass the electronic structure model entirely and replace it with a surrogate interatomic potential (IP), a functional form that may be fitted to theoretical data from a high fidelity ab initio model. The aim of this thesis is to provide a rigorous basis for IP models by justifying some of the underlying assumptions, in particular with an eye towards physics-informed machine learning approaches. More specifically, we consider the tight binding model, a quantum mechanical model sharing many similarities with the more complex Kohn-Sham density functional theories, and prove that the potential energy landscape (PEL) can be decomposed into atom-centred site energy contributions depending only on atoms within a small cut-off radius of the central atom. Moreover, we obtain error estimates for body-ordered approximations, which allows one to reduce the dimensionality of the site energy contributions. In particular, we are able to decompose the PEL into low dimensional components which are easier to analyse, manipulate, and fit.

Published
2021

16. Development of continuous-wave pump-enhanced optical parametric oscillators and their application to photo-thermal spectroscopy

Author

Thomas, Jack, Rae, Cameron Francis, Stothard, David J. M., and Dunn, Malcolm H.

Subjects
621.36, Optical parametric oscillator, Photo-thermal interferometric spectroscopy, Mid-infrared spectroscopy, Continuous mode-hop tuning, Sagnac interferometer, Single-frequency sources, Mid-infrared sources, Gas spectroscopy, Squeezed light generator
Abstract

The development of both a spectrally tunable radiation source and a sensitive detection transducer for spectroscopic applications are described in this thesis. The emission source is an optical parametric oscillator operating in the continuous-wave regime with a pump-enhanced singly-resonant architecture and involves the separate development of two constituent parts: A continuous-wave pump laser operating at 1064 nm based on neodymium-doped crystals focused on achieving high power whilst maintaining single-frequency operation; and a split-ring pump-enhanced optical parametric oscillator operating from this pump source focused on fine-tuning in mode-hops. This source was capable of coarsely tuning in the mid-infrared over 3 - 4 μm with an average of 140 mW of power with the ability of automated mode-hop tuning continuously over 90 cm⁻¹ in 0.07 cm⁻¹ steps. The detection transducer is based upon photo-thermal interferometric spectroscopy which employs a phase-sensitive method to detect the heating of a gas sample under radiation from the appropriately tuned source. Utilisation of a spectrally-independent probe beam permits samples with strong absorption features in the mid/deep-infrared to be examined whilst utilising the low-cost, high-sensitivity photodetectors in the visible/near-infrared region. This work implements both a Mach-Zehnder and a Sagnac interferometer, where the latter holds the potential to minimise the effects of the environment and simplify the associated experimental steps by removing stabilising electronic circuitry. Combined utilisation of this transducer alongside the excitation source has demonstrated an ability to detect the presence of ethane down to 100 parts-per-billion. Further development considered the interferometer inherent in photo-thermal spectroscopy, where this provides an avenue for employing optical squeezing techniques to increase the ultimate sensitivity of this technique. Construction of a squeezed light generator to use as a probe beam based on second-order nonlinearity has additionally been attempted in this work and has been shown to exhibit anti-squeezing characteristic behaviour.

Published
2021

17. Locality of Interatomic Forces in Tight Binding Models for Insulators

Author

Ortner, Christoph, Thomas, Jack, and Chen, Huajie

Subjects
Mathematical Physics, 74E15, 74G65
Abstract

The tight binding model is a minimalistic electronic structure model for predicting properties of materials and molecules. For insulators at zero Fermi-temperature we show that the potential energy surface of this model can be decomposed into exponentially localised site energy contributions, thus providing qualitatively sharp estimates on the interatomic interaction range which justifies a range of multi-scale models. For insulators at finite Fermi-temperature we obtain locality estimates that are uniform in the zero-temperature limit. A particular feature of all our results is that they depend only weakly on the point spectrum. Numerical tests confirm our analytical results. This work extends and strengthens (Chen, Ortner 2016) and (Chen, Lu, Ortner 2018) for finite temperature models., Comment: 23 pages, 6 figures

Published
2019
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18. Awareness and diagnosis for intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in neonatal (NICU) and pediatric intensive care units (PICU) – a follow-up multicenter survey

Author

Paul Wiegandt, Thomas Jack, Alexander von Gise, Kathrin Seidemann, Martin Boehne, Harald Koeditz, Philipp Beerbaum, Michael Sasse, and Torsten Kaussen

Subjects
Intraabdominal hypertension, Abdominal compartment syndrome, Survey, Newborn, Children, Neonatal intensive care, Pediatrics, RJ1-570
Abstract

Abstract Background Constantly elevated intra-abdominal pressure (IAH) can lead to abdominal compartment syndrome (ACS), which is associated with organ dysfunction and even multiorgan failure. Our 2010 survey revealed an inconsistent acceptance of definitions and guidelines among pediatric intensivists regarding the diagnosis and treatment of IAH and ACS in Germany. This is the first survey to assess the impact of the updated guidelines on neonatal/pediatric intensive care units (NICU/PICU) in German-speaking countries after WSACS published those in 2013. Methods We conducted a follow-up survey and sent 473 questionnaires to all 328 German-speaking pediatric hospitals. We compared our findings regarding awareness, diagnostics and therapy of IAH and ACS with the results of our 2010 survey. Results The response rate was 48% (n = 156). The majority of respondents was from Germany (86%) and working in PICUs with mostly neonatal patients (53%). The number of participants who stated that IAH and ACS play a role in their clinical practice rose from 44% in 2010 to 56% in 2016. Similar to the 2010 investigations, only a few neonatal/pediatric intensivists knew the correct WSACS definition of an IAH (4% vs 6%). Different from the previous study, the number of participants who correctly defined an ACS increased from 18 to 58% (p

Published
2023
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20. Bilateral lung transplantation for pediatric pulmonary arterial hypertension: perioperative management and one-year follow-up

Author

Thomas Jack, Julia Carlens, Franziska Diekmann, Hosan Hasan, Philippe Chouvarine, Nicolaus Schwerk, Carsten Müller, Ivonne Wieland, Igor Tudorache, Gregor Warnecke, Murat Avsar, Alexander Horke, Fabio Ius, Dmitry Bobylev, and Georg Hansmann

Subjects
pediatric, children, lung transplantation, pulmonary arterial hypertension, extracorporeal membrane oxygenation (ECMO), awake ECMO, Diseases of the circulatory (Cardiovascular) system, RC666-701
Abstract

BackgroundBilateral lung transplantation (LuTx) remains the only established treatment for children with end-stage pulmonary arterial hypertension (PAH). Although PAH is the second most common indication for LuTx, little is known about optimal perioperative management and midterm clinical outcomes.MethodsProspective observational study on consecutive children with PAH who underwent LuTx with scheduled postoperative VA-ECMO support at Hannover Medical School from December 2013 to June 2020.ResultsTwelve patients with PAH underwent LuTx (mean age 11.9 years; age range 1.9–17.8). Underlying diagnoses included idiopathic (n = 4) or heritable PAH (n = 4), PAH associated with congenital heart disease (n = 2), pulmonary veno-occlusive disease (n = 1), and pulmonary capillary hemangiomatosis (n = 1). The mean waiting time was 58.5 days (range 1–220d). Three patients were bridged to LuTx on VA-ECMO. Intraoperative VA-ECMO/cardiopulmonary bypass was applied and VA-ECMO was continued postoperatively in all patients (mean ECMO-duration 185 h; range 73–363 h; early extubation). The median postoperative ventilation time was 28 h (range 17–145 h). Echocardiographic conventional and strain analysis showed that 12 months after LuTx, all patients had normal biventricular systolic function. All PAH patients are alive 2 years after LuTx (median follow-up 53 months, range 26–104 months).ConclusionLuTx in children with end-stage PAH resulted in excellent midterm outcomes (100% survival 2 years post-LuTx). Postoperative VA-ECMO facilitates early extubation with rapid gain of allograft function and sustained biventricular reverse-remodeling and systolic function after RV pressure unloading and LV volume loading.

Published
2023
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24. Case report: Rescue treatment with add-on selexipag in a preterm infant with suprasystemic pulmonary hypertension, pulmonary capillary hemangiomatosis, and isolated pulmonary vein stenosis

Author

Hosan Hasan, Klea Hysko, Thomas Jack, Jens Dingemann, Martin Wetzke, and Georg Hansmann

Subjects
bronchopulmonary dysplasia (BPD), pulmonary hypertension (PH), neonatology, selexipag, prematurity, intensive care, Diseases of the circulatory (Cardiovascular) system, RC666-701
Abstract

An extremely dystrophic, premature female infant, born at 25 3/7 weeks of gestational age (birth weight: 430 g) with severe pulmonary hypertension (PH), was admitted to our neonatal intensive care unit (ICU) requiring cardiorespiratory support, including mechanical ventilation and pulmonary vasodilators such as inhaled nitric oxide (iNO) and continuous intravenous sildenafil infusions. The diagnosis of bronchopulmonary dysplasia (BPD) was made. A hemodynamically relevant, persistent ductus arteriosus (PDA) was surgically ligated after failed pharmacologic PDA closure using indomethacin and ibuprofen. The patient was discharged with an estimated 2/3 systemic pulmonary artery pressure. One month after hospital discharge, on low-flow oxygen supplementation (0.5 L/min FiO2 100%), at the corrected age of 16 weeks, she was readmitted to our emergency department with signs of respiratory distress and circulatory decompensation. Echocardiography demonstrated suprasystemic PH. Severe PH persisted despite initiated invasive mechanical ventilation, triple vasodilating therapy [iNO, macitentan, and continuous intravenous (IV) sildenafil], as well as levosimendan, milrinone, and norepinephrine for recompensation from cardiac shock. Thus, we started off-label oral selexipag therapy (oral IP receptor agonist) in the smallest patient reported so far (4 kg body weight). Subsequently, RV systolic pressure decreased to half-systemic, allowing successful weaning of iNO, norepinephrine, and milrinone, and extubation of the patient over 4 days. The infant was discharged 4 weeks after pediatric intensive care unit (PICU) admission in stable cardiorespiratory condition, with an oral, specific, triple antihypertensive PAH-targeted therapy using selexipag, macitentan, and sildenafil as well as oxygen therapy at low-flow (0.5 l/min) and spironolactone. The first cardiac catheterization at the age of 9 months under aforementioned triple PAH-targeted therapy revealed mild PH with 35% systemic PA pressure (mPAP/mSAP = 0.35) and isolated pulmonary vein stenosis. A transthoracic biopsy at the age of 12 months confirmed the diagnosis of BPD and further showed pulmonary interstitial glycogenosis and severe pulmonary capillary hemangiomatosis, without involvement of the pulmonary venules (chILD A2, A3, and B4 according to the Deutsch-Classification). The patient is currently in stable cardiorespiratory condition undergoing triple PH-targeted therapy including selexipag. This report highlights the potential benefits of the oral prostacyclin mimetic selexipag as an early add-on PH-targeted drug in chronic PH of infancy (cPHi).

Published
2022
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25. Acquired von Willebrand syndrome (AVWS) type 2, characterized by decreased high molecular weight multimers, is common in children with severe pulmonary hypertension (PH)

Author

Ivonne Wieland, Franziska Diekmann, Julia Carlens, Laura Hinze, Katharina Lambeck, Thomas Jack, and Georg Hansmann

Subjects
acquired von willebrand syndrome (AVWS), pulmonary hypertension, bleeding risk, high molecular weight multimers, children, Pediatrics, RJ1-570
Abstract

Background and objectivesEmerging evidence suggests that increased degradation of von Willebrand factor and decrease in high molecular weight multimers occurs in patients with pulmonary hypertension (PH). However, the link between acquired von Willebrand Syndrome (AVWS) type 2 and PH remains poorly understood.Material and methodsWe retrospectively evaluated the charts of 20 children with PH who underwent bilateral lung transplantation (LuTx) between 2013 and 2022. Von Willebrand variables were determined in 14 of these patients; 11 patients had complete diagnostics including multimer analysis.ResultsWe confirmed AVWS in 82% of the children studied (9 of 11 patients by multimer analysis). The two remaining patients had suspected AVWS type 2 because of a VWF:Ac/VWF:Ag ratio of 0.7 had abnormal VWF multimers, indicating AVWS type 2. Hemostatic complications were observed in 4 of 12 (33%) patients with VWS and 3 of 6 (50%) patients without diagnostics and therapy.ConclusionFor children with moderate to severe PH, we recommend systematic analysis of von Willebrand variables, including multimer analysis, PFA-100 and platelet function testing. Awareness of the diagnosis “AVWS” and adequate therapy may help to prevent these patients from bleeding complications in case of surgical interventions or trauma.

Published
2022
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26. Prediction models for SIRS, sepsis and associated organ dysfunctions in paediatric intensive care: study protocol for a diagnostic test accuracy study

Author

Andre Karch, Antje Wulff, Michael Marschollek, Philipp Beerbaum, Thomas Jack, Julia Böhnke, Nicole Rübsamen, Marcel Mast, Henning Rathert, Louisa Bode, Sven Schamer, Pronaya Prosun Das, Lena Wiese, Christian Groszewski-Anders, Andreas Haller, and Torsten Frank

Subjects
Pediatrics, RJ1-570
Abstract

Introduction Systemic inflammatory response syndrome (SIRS), sepsis and associated organ dysfunctions are life-threating conditions occurring at paediatric intensive care units (PICUs). Early recognition and treatment within the first hours of onset are critical. However, time pressure, lack of personnel resources, and the need for complex age-dependent diagnoses impede an accurate and timely diagnosis by PICU physicians. Data-driven prediction models integrated in clinical decision support systems (CDSS) could facilitate early recognition of disease onset.Objectives To estimate the sensitivity and specificity of previously developed prediction models (index tests) for the detection of SIRS, sepsis and associated organ dysfunctions in critically ill children up to 12 hours before reference standard diagnosis is possible.Methods and analysis We conduct a monocentre, prospective diagnostic test accuracy study. Clinicians in the PICU of the tertiary care centre Hannover Medical School, Germany, continuously screen and recruit patients until the adaptive sample size (originally intended sample size of 500 patients) is enrolled. Eligible are children (0–17 years, all sexes) who stay in the PICU for ≥12 hours and for whom an informed consent is given. All eligible patients are independently assessed for SIRS, sepsis and organ dysfunctions using corresponding predictive and knowledge-based CDSS models. The knowledge-based CDSS models serve as imperfect reference standards. The assessments are used to estimate the sensitivities and specificities of each predictive model using a clustered nonparametric approach (main analysis). Subgroup analyses (‘age groups’, ‘sex’ and ‘age groups by sex’) are predefined.Ethics and dissemination This study obtained ethics approval from the Hannover Medical School Ethics Committee (No. 10188_BO_SK_2022). Results will be disseminated as peer-reviewed publications, at scientific conferences, and to patients in an appropriate dissemination approach.Trial registration number This study was registered with the German Clinical Trial Register (DRKS00029071) on 2022-05-23.Protocol version 10188_BO_SK_2022_V.2.0–20220330_4_Studienprotokoll.

Published
2022
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28. Three dimensional chemical analysis of nanoparticles using energy dispersive X-ray spectroscopy

Author

Slater, Thomas Jack Alfred

Subjects
543, Electron tomography, Scanning transmission electron microscope, Energy dispersive X-ray spectroscopy, Bimetallic nanoparticles
Abstract

The aim of this thesis is to investigate the methodology of three dimensional chemical imaging of nanoparticles through the use of scanning transmission electron microscope (STEM) – energy dispersive X-ray (EDX) spectroscopy. In this thesis, an absorption correction factor is derived for spherical nanoparticles that can correct X-ray absorption effects. Quantification of EDX spectra of nanoparticles usually neglects X-ray absorption within the nanoparticle but may lead to erroneous results, thus an absorption correction is important for accurate compositional quantification. The absorption correction presented is verified through comparison with experimental data of Au X-ray peaks in spherical Au nanoparticles and is found to agree excellently. This absorption correction allows accurate compositional quantification of large ( > 100 nm) particles with STEM-EDX.Three dimensional chemical mapping is achievable through the use of EDX spectroscopy with electron tomography. Here, the methodology of STEM-EDX tomography is fully explored, with a focus on how to avoid artefacts introduced through detector shadowing and low counts per pixel. A varied-time acquisition scheme is proposed to correct for detector shadowing that is shown to provide a more constant intensity over a series of projections, allowing a higher fidelity reconstruction. The STEM-EDX tomography methodology presented is applied to the study of AgAu nanoparticles synthesized by the galvanic replacement reaction. The elemental distribution as a function of the composition of the as-synthesized nanoparticles is characterised and a reversal in the element segregated to the surface of the nanoparticles is found. The composition at which the reversal takes place is shown to correlate with a peak in the catalytic yield of a three component coupling reaction. It is hypothesized that a continuous Au surface results in the optimum catalytic conditions for the reaction studied, which guides the use of galvanically prepared AgAu nanoparticles as catalysts.

Published
2015

31. Elementary Teachers' and Principals' Perceptions of Principal Leadership Style and School Social Organization.

Author

Evans, Thomas Jack

Abstract

The context of teaching has changed dramatically in the wake of two national waves of educational reform. This dissertation examined the relationship between elementary principals' use of transformational leadership strategies as determined by teacher reports and the presence of social-organizational factors within the schools. The five social-organizational factors included shared goals, teacher collaboration, teacher learning, teacher certainty, and teacher commitment. Eighteen elementary principals and their faculties in a southwestern Michigan school district comprised the sample. Teachers (n=214) responded to both the Multifactor Leadership Questionnaire (B. Bass and B. Avolio, 1990) and the School Organizational Factors Questionnaire (S. Rosenholtz, 1990) for an overall return rate of 54 percent. Seventeen principals responded to the Multifactor Leadership Questionnaire. The data showed a significant correlation (r=.70; p=.00) between teachers' reports of principals' transformational leadership and their schools' social organization. Moreover, principals categorized as high in transformational leadership demonstrated a greater level of transformational leadership and led schools higher in social organization than did principals low in transformational leadership who led schools lower in social organization. Higher transformational principals were associated with schools that demonstrated enhanced levels of social organization reflective of effective schools. In addition, two intervening variables, principals' years of service with their present building and school staff size, were found to be significant predictors of principals' transformational leadership. (Contains 14 tables, 1 figure, and 76 references.) (LMI)

Published
1996

36. The ChatGPT Artificial Intelligence Chatbot: How Well Does It Answer Accounting Assessment Questions?

Author

Wood, David A., primary, Achhpilia, Muskan P., additional, Adams, Mollie T., additional, Aghazadeh, Sanaz, additional, Akinyele, Kazeem, additional, Akpan, Mfon, additional, Allee, Kristian D., additional, Allen, Abigail M., additional, Almer, Elizabeth D., additional, Ames, Daniel, additional, Arity, Viktor, additional, Barr-Pulliam, Dereck, additional, Basoglu, K. Asli, additional, Belnap, Andrew, additional, Bentley, Jeremiah W., additional, Berg, Terje, additional, Berglund, Nathan R., additional, Berry, Erica, additional, Bhandari, Avishek, additional, Bhuyan, Md Nazmul Hasan, additional, Black, Paul W., additional, Blondeel, Eva, additional, Bond, David, additional, Bonrath, Annika, additional, Borthick, A. Faye, additional, Boyle, Erik S., additional, Bradford, Marianne, additional, Brandon, Duane M., additional, Brazel, Joseph F., additional, Brockbank, Bryan G., additional, Burger, Marcus, additional, Byzalov, Dmitri, additional, Cannon, James N., additional, Caro, Cecil, additional, Carr, Abraham H., additional, Cathey, Jack, additional, Cating, Ryan, additional, Charron, Kimberly, additional, Chavez, Stacy, additional, Chen, Jason, additional, Chen, Jennifer C., additional, Chen, Jennifer W., additional, Cheng, Christine, additional, Cheng, Xu, additional, Christensen, Brant E., additional, Church, Kimberly Swanson, additional, Cicone, N. J., additional, Constance, Patience, additional, Cooper, Lauren A., additional, Correia, Candice L., additional, Coyne, Joshua, additional, Cram, W. Alec, additional, Curtis, Asher, additional, Daigle, Ronald J., additional, Dannemiller, Steve, additional, Davenport, Stephan A., additional, Dawson, Gregory S., additional, De Meyst, Karen J. L., additional, Dell, Scott, additional, Demirkan, Sebahattin, additional, Denison, Christine A., additional, Desai, Hrishikesh, additional, DeSimone, Steven, additional, Diehl, Leah M., additional, Dimes, Ruth, additional, Dong, Bei, additional, Donnelly, Amy, additional, du Pon, Adam, additional, Duan, Huijue Kelly, additional, Duffey, Ada, additional, Dunn, Ryan T., additional, Durkin, Mary P., additional, Dzuranin, Ann C., additional, Eberle, Rachel M., additional, Ege, Matthew S., additional, El Mahdy, Dina, additional, Esplin, Adam, additional, Eulerich, Marc, additional, Everaert, Patricia, additional, Farah, Nusrat, additional, Farish, Lauren, additional, Favere-Marchesi, Michael, additional, Fayard, Dutch, additional, Filosa, Jessica R., additional, Ford, Melinda, additional, Franz, Diana R., additional, Fulmer, Bachman P., additional, Fulmer, Sarah, additional, Furner, Zhan Z., additional, Gantman, Sonia, additional, Garner, Steve, additional, Garrett, Jace, additional, Geng, Xin, additional, Golden, Joanna, additional, Goldman, William, additional, Gomez, Josue, additional, Gooley, Mark, additional, Granitto, Shawn P., additional, Green, Karen Y., additional, Greenman, Cindy L., additional, Gupta, Gaurav, additional, Guymon, Ronald N., additional, Hale, Kevin, additional, Harper, Christopher J., additional, Hartt, S. Allen, additional, Hawk, Holly, additional, Hawkins, Steven R., additional, Hawkins, Erin M., additional, Hay, David C., additional, Heinzelmann, Rafael, additional, Henderson, Cassy D., additional, Hendricks, Bradley E., additional, Heninger, William G., additional, Hill, Mary S., additional, Holden, Nicole, additional, Holderness, D. Kip, additional, Holt, Travis P., additional, Hoopes, Jeffrey L., additional, Hsieh, Sheng-Feng, additional, Huang, Feiqi, additional, Huang, Hua-Wei, additional, Huang, Ting-Chiao, additional, Huels, Brian W., additional, Hunter, Kara, additional, Hurley, Patrick J., additional, Inger, Kerry, additional, Islam, Sharif, additional, Ison, Isaac, additional, Issa, Hussein, additional, Jackson, Andrew B., additional, Jackson, Scott C., additional, Janvrin, Diane J., additional, Jimenez, Peggy D., additional, Johanson, Daniel, additional, Judd, J. Scott, additional, Kawada, Brett S., additional, Kelton, Andrea Seaton, additional, Kern, Sara, additional, Kerr, Jon N., additional, Keune, Marsha B., additional, Kim, Mindy, additional, Knox, Brian D., additional, Kogan, Gregory, additional, Kotb, Amr, additional, Krane, Ronja, additional, Kremin, Joleen, additional, Krieg, Kimberly S., additional, Kugel, Jonathan, additional, Kulset, Ellen M., additional, Kuruppu, Chamara, additional, LaDuca, Garrison, additional, Lamberton, Barbara A., additional, Lamboy-Ruiz, Melvin A., additional, Lang, Bradley, additional, Larocque, Stephannie A., additional, Larson, Melissa P., additional, Lawson, Bradley P., additional, Lawson, James G., additional, Lee, Lorraine, additional, Lenk, Margarita M., additional, Li-Kuehne, Michelle, additional, Liljegren, Jonathan, additional, Lin, Yi-Hung, additional, Liu, Wu-Po, additional, Liu, Zishang, additional, Lock, Brandon, additional, Long, James H., additional, Loraas, Tina, additional, Lowensohn, Suzanne, additional, Loy, Thomas R., additional, Lyngstadaas, Hakim, additional, Maas, Wim, additional, MacGregor, Jason E., additional, Madsen, Dag Øivind, additional, Malone, Carissa L., additional, Margolin, Maximilian, additional, Marshall, Mary E., additional, Martin, Rachel M., additional, Mpofu, Colleen McClain, additional, McCoy, Chris, additional, McGuigan, Nicholas C., additional, McSwain, Dwayne N., additional, Meckfessel, Michele D., additional, Mellon, Mark J., additional, Melton, Olivia S., additional, Mercado, Julie M., additional, Mitsuda, Steven, additional, Modugu, Kennedy, additional, Moehrle, Stephen, additional, Chaghervand, Amirali Moeini, additional, Moffitt, Kevin, additional, Moon, Joon Seok, additional, Muehlmann, Brigitte, additional, Murray, Johnna, additional, Mwaungulu, Emmanuel S., additional, Myers, Noah, additional, Naegle, J. 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Published
2023
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40. Polynomial approximation of symmetric functions.

Author

Bachmayr, Markus, Dusson, Geneviève, Ortner, Christoph, and Thomas, Jack

Subjects
POLYNOMIAL approximation, SYMMETRIC functions, PERMUTATIONS, POLYNOMIALS
Abstract

We study the polynomial approximation of symmetric multivariate functions and of multi-set functions. Specifically, we consider f(x_1, \dots, x_N), where x_i \in \mathbb {R}^d, and f is invariant under permutations of its N arguments. We demonstrate how these symmetries can be exploited to improve the cost versus error ratio in a polynomial approximation of the function f, and in particular study the dependence of that ratio on d, N and the polynomial degree. These results are then used to construct approximations and prove approximation rates for functions defined on multi-sets where N becomes a parameter of the input. [ABSTRACT FROM AUTHOR]

Published
2024
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