Displaying Properties of PDFs

PDFVis is a computer program that assists in visualization of uncertainty as represented by a probability density function (PDF) located at each grid cell in a spatial domain. The functions that PDFV performs are listed

Unmotivated, Depressed, Anxious: Impact of the COVID-19 Emergency Transition to Remote Learning on Undergraduates’ Math Anxiety

In summer 2020, we invited the 6761 undergraduate students who took a Spring 2020 math course at the University of Arizona to participate in a survey, with 13% responding. We asked about their experience with the emergency transition to remote learning and measured their math anxiety before and after the transition using the well-established Abbreviated Math Anxiety Scale(AMAS). “Unmotivated, depressed, anxious” are the words one undergraduate used to describe their emergency transition to remote learning. Our results indicate that limited access to quality technology and inadequate communication with an instructor were the two greatest predictors for an increase in math anxiety after the emergency transition to remote learning. These results may encourage instructors to foster community with their students, especially during emergency remote learning

Low-cycle full-field residual strains in cortical bone and their influence on tissue fracture evaluated via in situ stepwise and continuous X-ray computed tomography

As a composite material, the mechanical properties of bone are highly dependent on its hierarchical organisation, thus, macroscopic mechanical properties are dictated by local phenomena, such as microdamage resulting from repetitive cyclic loading of daily activities. Such microdamage is associated with plastic deformation and appears as a gradual accumulation of residual strains. The aim of this study is to investigate local residual strains in cortical bone tissue following compressive cyclic loading, using in situ X-ray computed tomography (XCT) and digital volume correlation (DVC) to provide a deeper insight on the three-dimensional (3D) relationship between residual strain accumulation, cortical bone microstructure and failure patterns. Through a progressive in situ XCT loading–unloading scheme, localisation of local residual strains was observed in highly compressed regions. In addition, a multi-scale in situ XCT cyclic test highlighted the differences on residual strain distribution at the microscale and tissue level, where high strains were observed in regions with the thinnest vascular canals and predicted the failure location following overloading. Finally, through a continuous in situ XCT compression test of cycled specimens, the full-field strain evolution and failure pattern indicated the reduced ability of bone to plastically deform after damage accumulation due to high number of cyclic loads. Altogether, the novel experimental methods employed in this study, combining high-resolution in situ XCT mechanics and DVC, showed a great potential to investigate 3D full-field residual strain development under repetitive loading and its complex interaction with bone microstructure, microdamage and fracture

EFFICIENT SEARCHING DURING APPLICATION LAUNCH PROCESS

An application (e.g., a camera application, an entertainment application, a productivity application, a communication application, etc.) of a computing device (e.g., a smartphone, a laptop computer, a tablet computer, a smartwatch, etc.) may use a search module to efficiently search for application content (e.g., a graphical interface, a frame, etc.) to be displayed when the computing device launches the application. In some examples, the search module may be a Fibonacci-based algorithm that searches an application content repository in a sequence based on the Fibonacci sequence (e.g., 1, 2, 3, 5, 8 , etc.). In other examples, the search module may be a binary search algorithm that searches the application content repository in a sequence based on powers of two. Experiments show that both the Fibonacci-based algorithm and the binary search algorithm can find launch application content faster than some existing solutions. Thus, usage of search module 112 may advantageously decrease time-to-initial-display (TTID)

Nonlinear eigenvalue problem for optimal resonances in optical cavities

The paper is devoted to optimization of resonances in a 1-D open optical cavity. The cavity's structure is represented by its dielectric permittivity function e(s). It is assumed that e(s) takes values in the range 1 <= e_1 <= e(s) <= e_2. The problem is to design, for a given (real) frequency, a cavity having a resonance with the minimal possible decay rate. Restricting ourselves to resonances of a given frequency, we define cavities and resonant modes with locally extremal decay rate, and then study their properties. We show that such locally extremal cavities are 1-D photonic crystals consisting of alternating layers of two materials with extreme allowed dielectric permittivities e_1 and e_2. To find thicknesses of these layers, a nonlinear eigenvalue problem for locally extremal resonant modes is derived. It occurs that coordinates of interface planes between the layers can be expressed via arg-function of corresponding modes. As a result, the question of minimization of the decay rate is reduced to a four-dimensional problem of finding the zeroes of a function of two variables.Comment: 16 page

Quark Coulomb Interactions and the Mass Difference of Mirror Nuclei

We study the Okamoto-Nolen-Schiffer (ONS) anomaly in the binding energy of mirror nuclei at high density by adding a single neutron or proton to a quark gluon plasma. In this high-density limit we find an anomaly equal to two-thirds of the Coulomb exchange energy of a proton. This effect is dominated by quark electromagnetic interactions---rather than by the up-down quark mass difference. At normal density we calculate the Coulomb energy of neutron matter using a string-flip quark model. We find a nonzero Coulomb energy because of the neutron's charged constituents. This effect could make a significant contribution to the ONS anomaly.Comment: 4 pages, 2 figs. sub. to Phys. Rev. Let