1,421 research outputs found
Coherent Diffractive Imaging Using Randomly Coded Masks
Coherent diffractive imaging (CDI) provides new opportunities for high
resolution X-ray imaging with simultaneous amplitude and phase contrast.
Extensions to CDI broaden the scope of the technique for use in a wide variety
of experimental geometries and physical systems. Here, we experimentally
demonstrate a new extension to CDI that encodes additional information through
the use of a series of randomly coded masks. The information gained from the
few additional diffraction measurements removes the need for typical
object-domain constraints; the algorithm uses prior information about the masks
instead. The experiment is performed using a laser diode at 532.2 nm, enabling
rapid prototyping for future X-ray synchrotron and even free electron laser
experiments. Diffraction patterns are collected with up to 15 different masks
placed between a CCD detector and a single sample. Phase retrieval is performed
using a convex relaxation routine known as "PhaseCut" followed by a variation
on Fienup's input-output algorithm. The reconstruction quality is judged via
calculation of phase retrieval transfer functions as well as by an object-space
comparison between reconstructions and a lens-based image of the sample. The
results of this analysis indicate that with enough masks (in this case 3 or 4)
the diffraction phases converge reliably, implying stability and uniqueness of
the retrieved solution
Fatherhood Education During the Pandemic
This article highlights the transition of Healthy Relationships Utah from in-person to virtual fatherhood education workshops during the COVID-19 pandemic. Overall, evaluation results showed no differences in program outcomes between in-person and virtual formats. Qualitative data from virtual participants illustrates the benefits and challenges of virtual program delivery
An Examination of Geographic and Socio- Demographic Impacts on Private Industry Job Change in the Dakotas, 2002 – 2008
This study examines geographic and socio-demographic factors associated with private industry job change in North and South Dakota from 2002 to 2008. We conceptualize private industries as enterprises or businesses that are individually or corporately owned and operated outside the public sector. County-level occupational data were captured using the U.S. Census Bureau’s Quarterly Workforce Indicators (QWI). Results indicate that percentage of workers commuting to another county for work, median household income, the percentage of residents identifying as American Indian and Alaska Native, and population change were significant predictors of county-level private industry job change
Well-being among Older Adults in Mississippi: Exploring Differences between Metropolitan, Micropolitan, and Noncore Rural Settings
It is a common belief that older adults in rural areas have high subjective well-being, despite often experiencing greater poverty and having access to fewer resources than older adults who live in urban areas, a phenomenon sometimes referred to as the “rural-urban paradox.” However, research does not consistently find high well-being in rural areas, which might be due to research not distinguishing between very rural and semi-rural (or small town) settings. This study compares the subjective well-being of older adults in micropolitan and noncore counties with the well-being of older adults in metropolitan areas in Mississippi (n = 659). Preliminary results indicate metropolitan respondents reporting higher subjective well-being than both micropolitan and noncore respondents. However, after accounting for key covariates, micropolitan residents were found to have significantly lower levels of subjective well- being compared to metropolitan residents. Overall, our study suggests that micropolitan settings may be less conducive to healthy, successful aging when compared to metropolitan settings
A High-Performance Implementation of Atomistic Spin Dynamics Simulations on x86 CPUs
Atomistic spin dynamics simulations provide valuable information about the
energy spectrum of magnetic materials in different phases, allowing one to
identify instabilities and the nature of their excitations. However, the time
cost of evaluating the dynamical correlation function
increases quadratically as the number of spins , leading to significant
computational effort, making the simulation of large spin systems very
challenging. In this work, we propose to use a highly optimized general matrix
multiply (GEMM) subroutine to calculate the dynamical spin-spin correlation
function that can achieve near-optimal hardware utilization. Furthermore, we
fuse the element-wise operations in the calculation of into
the in-house GEMM kernel, which results in further performance improvements of
44\% - 71\% on several relatively large lattice sizes when compared to the
implementation that uses the GEMM subroutine in OpenBLAS, which is the
state-of-the-art open source library for Basic Linear Algebra Subroutine
(BLAS).Comment: 18 (short) pages, 6 figure
Kernel Fusion in Atomistic Spin Dynamics Simulations on Nvidia GPUs using Tensor Core
In atomistic spin dynamics simulations, the time cost of constructing the
space- and time-displaced pair correlation function in real space increases
quadratically as the number of spins , leading to significant computational
effort. The GEMM subroutine can be adopted to accelerate the calculation of the
dynamical spin-spin correlation function, but the computational cost of
simulating large spin systems ( spins) on CPUs remains expensive. In
this work, we perform the simulation on the graphics processing unit (GPU), a
hardware solution widely used as an accelerator for scientific computing and
deep learning. We show that GPUs can accelerate the simulation up to 25-fold
compared to multi-core CPUs when using the GEMM subroutine on both. To hide
memory latency, we fuse the element-wise operation into the GEMM kernel using
that can improve the performance by 26% 33% compared
to implementation based on . Furthermore, we perform the
on-the-fly calculation in the epilogue of the GEMM subroutine to avoid saving
intermediate results on global memory, which makes the large-scale atomistic
spin dynamics simulation feasible and affordable
Structural Conditions and Migration in the Dakotas
This study examines the influence of selected structural conditions on the county-level net-migration trends of North Dakota and South Dakota. Key principles from Lee’s Theory of Migration (1966) and Wallerstein’s World Systems model (1974) were integrated to explain how geographic context, economic dependency, and pace of economic development combine to serve as the main catalysts behind the migration patterns in these two states. Results indicate that commuting patterns, the percentage of workers employed in extractive industries, the percentage of workers employed in manufacturing, and job change rates were significant predictors of county migration patterns
What Do You Want to Accomplish in the Next 10 Years? The Goals of Emerging Adults
Emerging adulthood is a period characterized by transition. Individuals in this stage of development find themselves in between adolescence and young adulthood, faced with consequential decisions related to their educational attainment, career trajectory, and the overall direction of their life course. This study focused on the goal-setting behavior of emerging adults. Data were collected through interviews with individuals between the ages of 18 and 25 (N = 91). It was expected that the goals of this group would be oriented toward more individualistic pursuits, with less emphasis placed on more collectivistic goals. It also was anticipated that interviewees would have wide-ranging and multiple goals, which is reflective of the exploratory nature of emerging adulthood. Results show partial support for these hypotheses as interviewees listed more collectivistic goals than anticipated, but also were likely to list multiple and wideranging goals
Indicators of Supportive Service Need Among Older Adults in Mississippi
Providing quality services is one of the challenges associated with the continued increase in the nation’s older adult population. Effective use of needs assessment data can be useful in assessing service need. This study measures the level of perceived need for supportive services among older adults in Mississippi. Using statewide needs assessment data, this study applies the Behavioral Model to measure the perceived need for supportive services among survey participants aged 60 and older (N = 838). Results indicate that age, race, physical health, and subjective well-being were consistent predictors of perceived need for supportive services. Results suggest the importance of understanding the factors associated with the perceived need for supportive services to more effectively plan service delivery
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