Digital Commons Network^™

On The Highly Connected Dyadic, Near-Regular, And Sixth-Root-Of-Unity Matroids, Ben Clark, Kevin Grace, James Oxley, Stefan H.M. Van Zwam

Faculty Publications

Subject to announced results by Geelen, Gerards, and Whittle [Towards a structure theory for matrices and matroids, in Proceedings of the International Congress of Mathematicians, Vol. III, 2006, pp. 827-842], we completely characterize the highly connected members of the classes of dyadic, near-regular, and sixth-root-of-unity matroids.

(Sl(N),Q) -Opers, The Q-Langlands Correspondence, And Quantum/Classical Duality, Peter Koroteev, Daniel S. Sage, Anton M. Zeitlin

Faculty Publications

A special case of the geometric Langlands correspondence is given by the relationship between solutions of the Bethe ansatz equations for the Gaudin model and opers-connections on the projective line with extra structure. In this paper, we describe a deformation of this correspondence for SL(N). We introduce a difference equation version of opers called q-opers and prove a q-Langlands correspondence between nondegenerate solutions of the Bethe ansatz equations for the XXZ model and nondegenerate twisted q-opers with regular singularities on the projective line. We show that the quantum/classical duality between the XXZ spin chain and the trigonometric Ruijsenaars–Schneider model may …

Discovery And Confirmation Of The Shortest Gamma-Ray Burst From A Collapsar, T Ahumada, L P. Singer, S Anand, M W. Coughlin, T Ahumada, G Ryan, I Andreoni, S B. Cenko, C Fremling, H Kumar, P T. Pang, E Burns, V Cunningham, S Dichiara, T Dietrich, D S. Svinkin, M S. Almualla, A J. Castro-Tirado, K De, R Dunwoody, P Gatkine, E Hammerstein, S Iyyani, J Mangan, E Perley, S Purkayastha, E Bellm, V Bhalerao, B Bolin, M Bulla, C Cannella, P Chandra, D A. Duev, D Frederiks, A. Gal-Yam, M. Graham, A. Y. Q. Ho, K. Hurley, V. Karambelkar, E. C. Kool, S. R. Kulkarni, A. Mahabal, F. Masci, S. Mcbreen, S. B. Pandey, S. Reusch, A. Ridnaia, P. Rosnet, B. Rusholme, A. S. Carracedo, R. Smith, M. Soumagnac, R. Stein, E. Troja, A. Tsvetkova, R. Walters, A. F. Valeev

Faculty Publications

Gamma-ray bursts (GRBs) are among the brightest and most energetic events in the Universe. The duration and hardness distribution of GRBs has two clusters(1), now understood to reflect (at least) two different progenitors(2). Short-hard GRBs (SGRBs; T-90 < 2 s) arise from compact binary mergers, and long-soft GRBs (LGRBs; T-90 > 2 s) have been attributed to the collapse of peculiar massive stars (collapsars)(3). The discovery of SN 1998bw/GRB 980425 (ref. (4)) marked the first association of an LGRB with a collapsar, and AT 2017gfo (ref. (5))/GRB 170817A/GW170817 (ref. (6)) marked the first association of an SGRB with a binary neutron star merger, which also produced a gravitational wave. Here, we present the discovery …

Supernova Model Discrimination With Hyper-Kamiokande, K Abe, P Adrich, H Aihara, R Akutsu, K Abe, A Ali, F Ameli, I Anghel, L H. Anthony, M Antonova, A Araya, Y Asaoka, Y Ashida, V Aushev, F Ballester, I Bandac, M Barbi, G J. Barker, G Barr, M Batkiewicz-Kwasniak, M Bellato, V Berardi, M Bergevin, L Bernard, S Bernardini, L Berns, S Bhadra, J Bian, A Blanchet, F D. Blaszczyk, A Blondel, A Boiano, S Bolognesi, L Bonavera

Faculty Publications

Core-collapse supernovae are among the most magnificent events in the observable universe. They produce many of the chemical elements necessary for life to exist and their remnants-neutron stars and black holes-are interesting astrophysical objects in their own right. However, despite millennia of observations and almost a century of astrophysical study, the explosion mechanism of core-collapse supernovae is not yet well understood. Hyper-Kamiokande is a next-generation neutrino detector that will be able to observe the neutrino flux from the next galactic core-collapse supernova in unprecedented detail. We focus on the first 500 ms of the neutrino burst, corresponding to the accretion …

Stability Analysis For Time-Varying Systems With Asynchronous Sampling Using Contractivity Approach, Frederic Mazenc, Michael Malisoff, Miroslav Krstic

Faculty Publications

We provide new sufficient conditions for a generalized exponential input-to-state stability condition to hold. Our proofs use innovative trajectory based contractivity and cooperative systems arguments. Another key ingredient is a new variant of Halanay's inequality, which differs from prior Halanay inequalities because of its use of sampling. Our sufficient conditions allow arbitrarily long intervals between some consecutive sampling times, provided the intervals between consecutive sampling times are frequently small enough. This removes a significant limitation of prior results that relied on versions of Halanay's inequality that did not contain sampling. Unlike standard stability conditions, the upper bounds for the norm …

Stability And Observer Designs Using New Variants Of Halanay's Inequality, Frédéric Mazenc, Michael Malisoff, Miroslav Krstic

Faculty Publications

We provide a generalization of Halanay's inequality, where the decay rate is constant but the gain multiplying the delayed term is time varying. While the usual Halanay's conditions require the decay rate to be strictly larger than an upper bound on the gain, our less restrictive results allow times when the gain can exceed the decay rate. This allows us to prove asymptotic stability in significant cases that were not amenable to previous Lyapunov function constructions, and in cases that violate the contraction requirement that was needed to prove asymptotic stability in previous trajectory based results. We apply our work …

Preschool Mathematics Performance And Executive Function: Rural-Urban Comparisons Across Time, Jacob A. Esplin, Ann M. Berghout Austin, Belinda Blevins-Knabe, Brionne G. Neilson, Robert F. Corwyn

Faculty Publications

This longitudinal study examined the relationship between executive function (EF) and mathematics with rural and urban preschool children. A panel of direct and indirect EF measures were used to compare how well individual measures, as well as analytic approaches, predicted both numeracy and geometry skill. One hundred eighteen children, ages 39 to 68 months, were given EF and mathematics assessments twice, approximately six months apart, concurrent to their teachers completing an indirect assessment of EF for each child. Results suggest: (1) the child’s age determines if a panel of direct EF measures is a better predictor of numeracy and geometry …

Howard Gardner's Multiple Intelligences Theory And His Ideas On Promoting Creativity, Hani Morgan

Faculty Publications

This book chapter highlights Howard Gardner's contributions to the areas of education and creativity. It includes an introductory section on his background and accomplishments. The chapter focuses on his theory of multiple intelligences, Gardner's best-known theory, and provides details on how he got the idea for this theory. It offers an explanation of this theory and the implications it has for educators. His theory of human intelligence contradicts the view that there is one type of intelligence that could be measured by standardized tests. Gardner first described seven intelligences and later added an eighth. The chapter also focuses on Gardner's …

Solopreneur Digital Ecosystems: Genesis, Lineage And Preliminary Categorization, Gabriele Piccoli, Biagio Palese, Joaquin Rodriguez

Faculty Publications

This paper traces the genesis and lineage of solopreneur digital ecosystems. These ecosystems, fostered by a digital environment that is infrastructural, combinatorial and servitized, are enabling the rise to prominence of the solopreneur. We theorize solopreneur digital ecosystems as the latest incarnation of systems beyond firm control, with digital platforms and digital marketplaces as their principal enablers. In an effort to compare them from the perspective of the solopreneur, we categorize solopreneur digital ecosystems on three dimensions: algorithmic control, commoditization, and lock-in. Our work contributes a framework that solopreneurs can use to identify ecosystems in which they can optimally invest …

Solopreneur Digital Ecosystems: Genesis, Lineage And Preliminary Categorization, Gabriele Piccoli, Biagio Palese, Joaquin Rodriguez

Faculty Publications

This paper traces the genesis and lineage of solopreneur digital ecosystems. These ecosystems, fostered by a digital environment that is infrastructural, combinatorial and servitized, are enabling the rise to prominence of the solopreneur. We theorize solopreneur digital ecosystems as the latest incarnation of systems beyond firm control, with digital platforms and digital marketplaces as their principal enablers. In an effort to compare them from the perspective of the solopreneur, we categorize solopreneur digital ecosystems on three dimensions: algorithmic control, commoditization, and lock-in. Our work contributes a framework that solopreneurs can use to identify ecosystems in which they can optimally invest …

Peridynamics For Quasistatic Fracture Modeling, Debdeep Bhattacharya, Patrick Diehl, Robert P. Lipton

Faculty Publications

Fracture involves interaction across large and small length scales. With the application of enough stress or strain to a brittle material, atomistic scale bonds will break, leading to fracture of the macroscopic specimen. From the perspective of mechanics fracture should appear as an emergent phenomena generated by a continuum field theory eliminating the need for a supplemental kinetic relation describing crack growth. We develop a new fast method for modeling quasi-static fracture using peridynamics. We apply fixed point theory and model stable crack evolution for hard and soft loading. For soft loading we recover unstable fracture. For hard loading we …

Feedback Stabilization With Discrete Measurements Using Bounds On Fundamental Matrices, Frederic Mazenc, Michael Malisoff

Faculty Publications

We prove a new robust stabilization theorem for systems with time-varying disturbances and sampled measurements, using novel bounds on fundamental matrices for systems with disturbances. Our main tools use properties of positive systems and Metzler matrices. Our numerical example illustrates an advantage of using our method instead of previous methods.

New Fixed Time And Fast Converging Reduced Order Observers, Frederic Mazenc, Michael Malisoff

Faculty Publications

For nonlinear continuous-time systems with continuous measurements of the output, we provide new reduced order observers that converge in finite time. The convergence time is independent of the initial state. For cases where the measurements are discrete, we provide asymptotically converging observers, whose rate of convergence is proportional to the negative of the logarithm of the size of the sampling interval. Our observers are based on the observability Gramian.

Subgroups Of Right-Angled Coxeter Groups Via Stallings-Like Techniques, Pallavi Dani, Ivan Levcovitz

Faculty Publications

We associate cube complexes called completions to each subgroup of a right-angled Coxeter group (RACG). A completion characterizes many properties of the subgroup such as whether it is quasiconvex, normal, finite-index or torsion-free. We use completions to show that reflection subgroups are quasiconvex, as are one-ended Coxeter subgroups of a 2-dimensional RACG. We provide an algorithm that determines whether a given one-ended, 2-dimensional RACG is isomorphic to some finite-index subgroup of another given RACG. In addition, we answer several algorithmic questions regarding quasiconvex subgroups. Finally, we give a new proof of Haglund’s result that quasiconvex subgroups of RACGs are separable.

Teachers Connecting With Rural Students And Places: A Mixed Methods Analysis, Angie Starrett, Jan A. Yow Ph.D., Christine Lotter Ph.D., Matthew J. Irvin Ph.D., Paula Adams

Faculty Publications

Our study explores how teachers’ living proximity to their school and level of social connection to their rural community may influence implementation of place-based education and student-teacher relationships in mathematics and science classrooms. Both quantitative and qualitative results from 4126 students and 19 teachers reveal homegrown teachers (live in community where they grew up) highly value and excel at student-teacher relationships. Conversely, less socially connected commuters excel at implementing place-based education. Implications of our study provide new directions for recruiting rural teachers, aside from focusing on those from within the rural community.

Social Emotional Learning And The National Core Arts Standards: A Cross-Disciplinary Analysis Of Policy And Practices, Mark Graham, Matt Omasta, Stephanie L. Milling, Elizabeth Murray, Amy Peterson Jensen, Johanna J. Siebert

Faculty Publications

Arts education advocates sometimes point to extrinsic benefits of arts learning, including Social Emotional Learning (SEL). This study considers if and how the National Core Arts Standards (NCAS) in dance, media arts, music, theater, and visual art may align with SEL standards adopted by the state of Illinois, upon which other SEL standards have been modeled. A team of arts education experts coded 15,500 intersections of arts standards &SEL goals. They found a great deal of indirect alignment between the NCAS and SEL objectives, but direct alignment was rare. As the types and degrees of alignment varied by discipline, broad …

Don't Call Us, We'll Call You: An Empirical Study Of Caller Behavior Under A Callback Option, Brett A. Hathaway, Seyed Morteza Emadi, Vinayak Deshpande

Faculty Publications

While call centers have recently invested in callback technology, the impact of this innovation on caller behavior and call center performance is not clearly understood. Using call center data from a US commercial bank, we perform an empirical study of the callers' decision-making process in the presence of a callback option. We formulate a structural model of the caller decision-making process, and impute their underlying preferences from the data. Our estimates show that callers experience substantially less discomfort per unit of time while waiting for callbacks than while waiting in queue. However, we also find that, after controlling for expected …

The Effect Of Help Seeking On Creative Self- Efficacy Of Is Students, Cherileigh Leavitt, Madison Corbin, Mark J. Keith, Ryan M. Schuetzler, Degan Kettles, Greg Anderson

Faculty Publications

Research has demonstrated that student help-seeking behaviors have a variety of positive influences in the classroom. However, the primary outcome of these studies is typically student grades and general self-efficacy. To make a contribution to the IS discipline, we expand this research with a more targeted and specific measure of self-efficacy that was created for IS students: creative self-efficacy (CreaSE) in the IS discipline. This allows us to relate specific help-seeking behaviors to CreaSE sub-constructs which, in turn, allows us to make more targeted recommendations to instructors in IS programs who want to improve the quality and retention of their …

Improving The Quality Of Survey Data: Using Answering Behavior As An Alternative Method For Detecting Biased Respondents, Manasvi Kumar, David Kim, Joseph S. Valacich, Jeffrey L. Jenkins, Alan R. Dennis

Faculty Publications

Online surveys are used for collecting self-report data. Despite their prevalent use, data quality problems persist due to various response biases. Here, we demonstrate how participant answering behaviors can be used to identify biased responses. We administered an online survey where participants reported their personality dimensions of neuroticism and extraversion—two personality dimensions that have been previously shown to be correlated with a propensity to deceive—and were later presented with a scenario to exhibit deceptive behavior. We then generated models to predict deception using the neuroticism and extraversion constructs. Using respondents’ fine-grained mouse movement data when answering these questions, we generated …

Arctic Observations And Numerical Simulations Of Surface Wind Effects On Multi-Angle Snowflake Camera Measurements, Kyle E. Fitch, Chaoxun Hang, Ahmad Talaei, Timothy Garrett

Faculty Publications

Ground-based measurements of frozen precipitation are heavily influenced by interactions of surface winds with gauge-shield geometry. The Multi-Angle Snowflake Camera (MASC), which photographs hydrometeors in free-fall from three different angles while simultaneously measuring their fall speed, has been used in the field at multiple midlatitude and polar locations both with and without wind shielding. Here, we present an analysis of Arctic field observations – with and without a Belfort double Alter shield – and compare the results to computational fluid dynamics (CFD) simulations of the airflow and corresponding particle trajectories around the unshielded MASC. MASC-measured fall speeds compare well with …

Model And Data, Equilibrium Of Self-Formed, Single-Thread, Sand-Bed Rivers, Enrica Viparelli, Esther C. Eke

Faculty Publications

This submission contains the following files, also uploaded as Supplementary Information for the manuscript Equilibrium of self-formed, single-thread, sand-bed rivers submitted after major revisions to the AGU journal Geophysical Research Letters.

Excel file with embedded macro Equilibrium_calculator.xlxm, contains the solver of the analytical model presented in the manuscript.

Excel file Equilibrium_results.xlxs contains model data used to generate the plots.

We Too Are Guardians Of Truth, John R. Rachal

Faculty Publications

In our current tribalized social and political culture, an even greater premium is placed upon the necessity of educators inculcating a skeptical, truth-seeking habit of mind in their learners. This brief essay offers an exploration of this role both from the perspectives of adult education and liberal education.

Commuting Perturbations Of Operator Equations, Xue Xu, Jiu Ding

Faculty Publications

Let X be a Banach space and let T: X →X be a bounded linear operator with closed range. We study a class of commuting perturbations of the corresponding operator equation, using the concept of the spectral radius of a bounded linear operator. Our results extend the classic perturbation theorem for invertible operators and its generalization for arbitrary operators under the commutability assumption.

A Story Of Bodying In Science Education, Christie C. Byers, Maria F.G. Wallace

Faculty Publications

In poetic dialogue with BecomingAlivewithinScienceEducation(Research):ThinkingwithLifeHistory(ies),BodiesandStickiness, stories of bodying and body(ies) of work are playfully explored.

Privacy-Preserving Non-Participatory Surveillance System For Covid-19-Like Pandemics, Mahmoud Nabil, Ahmed Sherif, Mohamed Mahmoud, Waleed Alsmary, Maazen Alsabaan

Faculty Publications

COVID-19 pandemic has revealed a pressing need for an effective surveillance system to control the spread of infection. However, the existing systems are run by the people’s smartphones and without a strong participation from the people, the systems become ineffective. Moreover, these systems can be misused to spy on people and breach their privacy. Due to recent privacy breaches, people became anxious about their privacy, and without privacy reassurance, the people may not accept the systems. In this paper, we propose a non-participatory privacy-preserving surveillance system for COVID-19-like pandemics. The system aims to control the spread of COVID-19 infection without …

3d Fusion Between Fluoroscopy Angiograms And Spect Myocardial Perfusion Images To Guide Percutaneous Coronary Intervention, Haipeng Tang, Robert R. Bober, Chen Zhao, Chaoyang Zhang, Huiqing Zhu, Zhuo He, Zhihui Xu, Weihua Zhou

Faculty Publications

Background

Percutaneous coronary intervention (PCI) in stable coronary artery disease (CAD) is commonly triggered by abnormal myocardial perfusion imaging (MPI). However, due to the possibilities of multivessel disease, serial stenoses and variability of coronary artery perfusion distribution, an opportunity exists to better align anatomic stenosis with perfusion abnormalities to improve revascularization decisions. This study aims to develop a multi-modality fusion approach to assist decision-making for PCI.

Methods and Results

Coronary arteries from fluoroscopic angiography (FA) were reconstructed into 3D artery anatomy. Left ventricular (LV) epicardial surface was extracted from SPECT. The artery anatomy and epicardial surface were non-rigidly fused. The …

Thermal-Induced Unfolding-Refolding Of A Nucleocapsid Covn Protein, Warin Rangubpit, Pornthep Sompornpisut, R. B. Pandey

Faculty Publications

Unfolding of a coarse-grained COVN protein from its native configuration shows a linear response with increasing temperature followed by non-monotonic double peaks in its radius of gyration. The protein conforms to a random coil of folded segments in native state with increasingly tenuous and globular structures in specific temperature regimes where the effective dimensions of corresponding structures D ≈ 1.6–2.4. Thermal agitation alone is not sufficient to fully eradicate its segmental folding as few local folds are found to persist around such residues as ⁶⁵L, ¹¹⁰Y, ²²⁴L, ³⁷⁴P even at high temperatures.

On The Origin And Structure Of The First Sharp Diffraction Peak Of Amorphous Silicon, Devilal Dahal, Hiroka Warren, Parthapratim Biswas

Faculty Publications

The structure of the first sharp diffraction peak (FSDP) of amorphous silicon (a-Si) near 2 Å⁻¹ is addressed with particular emphasis on the position, intensity, and width of the diffraction curve. By studying a number of continuous random network (CRN) models of a-Si, it is shown that the position and intensity of the FSDP are primarily determined by radial atomic correlations in the amorphous network on the length scale of 15 Å. A shell-by-shell analysis of the contribution from different radial shells reveals that key contributions to the FSDP originate from the second and fourth radial shells in the …

Policy Interactions In Large-Scale Marine Protected Areas, Rebecca L. Gruby, Noella J. Gray, Luke Fairbanks, Elizabeth Havice, Lisa M. Campbell, Alan Friedlander, Kirsten L.L. Oleson, King Sam, Lillian Mitchell, Quentin Hanich

Faculty Publications

Large-scale marine protected areas (LSMPAs) have proliferated in recent years, now accounting for most of the world's MPA coverage. However, little is known about LSMPA outcomes and the factors that affect them. Here we argue that policy interactions—the cumulative effect of co-existing policies for an issue and/or geographical area—can play a critical, but under-recognized, role in influencing LSMPA design and outcomes. We analyze interactions between national LSMPAs within Palau and Kiribati, and regional fisheries management established by the Nauru Agreement to show how policy actors can account for policy interactions in LSMPA design, and to demonstrate the profound influence that …

Characterisation Of Nano-Assemblies Inside Mesopores Using Neutron Scattering*, Yingzhen Ma, William T. Heller, Lilin He, William A. Shelton, Gernot Rother, Bhuvnesh Bharti

Faculty Publications

Adsorption of molecular and nanoscale matter in mesoporous materials is important in filtration and chromatography as well as membrane processes. However, the morphology and distribution of self-assembled structures of adsorbate formed within nanoconfined environments is largely unknown. Small Angle Neutron Scattering (SANS) with porous matrix matching the neutron scattering length density of the solvent has the potential to provide detailed information on the self-assemblies formed in pore spaces. However, analysis of such SANS profiles remains a challenge. In this study, we extend the SANS analysis method previously developed by Findenegg and co-workers to include interparticle correlations, providing a qualitative characterisation …