185 research outputs found
On the performance of algorithms for the minimization of -penalized functionals
The problem of assessing the performance of algorithms used for the
minimization of an -penalized least-squares functional, for a range of
penalty parameters, is investigated. A criterion that uses the idea of
`approximation isochrones' is introduced. Five different iterative minimization
algorithms are tested and compared, as well as two warm-start strategies. Both
well-conditioned and ill-conditioned problems are used in the comparison, and
the contrast between these two categories is highlighted.Comment: 18 pages, 10 figures; v3: expanded version with an additional
synthetic test problem
The ethics of uncertainty for data subjects
Modern health data practices come with many practical uncertainties. In this paper, I argue that data subjectsâ trust in the institutions and organizations that control their data, and their ability to know their own moral obligations in relation to their data, are undermined by significant uncertainties regarding the what, how, and who of mass data collection and analysis. I conclude by considering how proposals for managing situations of high uncertainty might be applied to this problem. These emphasize increasing organizational flexibility, knowledge, and capacity, and reducing hazard
The association between the functional movement screen (tm), y-balance test, and physical performance tests in male and female high school athletes
Background: Poor balance, lack of neuromuscular control, and movement ability are predictors of performance and injury risk in
sports and physical activity participation. The Functional Movement Screenâą (FMSâą) and lower quarter Y-Balance Test (YBT) have
been used by clinicians to evaluate balance, functional symmetry, and static and dynamic movement patterns, yet little information exists regarding the relationship between the FMSâą, YBT, and physical performance tests (e.g. vertical jump) within the high
school population.
Purpose: The purpose of this study was to investigate the relationship between the FMSTM, dynamic balance as measured by the
YBT and physical performance tests (standing long jump, vertical jump, Pro Agility Test) in male and female high school
athletes.
Study Design: Cohort study.
Methods: Fifty-six high school athletes (28 females, 28 males; mean age 16.4 ± 0.1) who participated in organized team sports were
tested. Participants performed the FMSâą, YBT, and three physical performance tests (standing long jump, vertical jump, Pro Agility
Test).
Results: Females outperformed males on the FMSâą and YBT, while males outperformed females on the performance tests. In both
sexes, the composite FMSTM score was positively correlated with the left and composite YBT scores. Agility was negatively correlated with composite FMSTM in males (p < 0.05) and the left and composite YBT in females (p < 0.05).
Conclusions: The FMST M and YBT may evaluate similar underlying constructs in high school athletes, such as dynamic balance
and lower extremity power. The results of this study demonstrate the utility of the FMS and YBT to relate multiple constructs of
muscular power to an individualâs ability to balance. Furthermore, establishing the need for the utilization and application of
multiple field-based tests by sports medicine professionals and strength and conditioning coaches when evaluating an athleteâs
movement and physical performance capabilities. Utilization of multiple field-based tests may provide the first step for the development of injury prevention strategies and long-term athlete development programs
Ăndice de Massa Corporal, Idade, Maturação Sexual e a IncidĂȘncia de Hiperlordose Lombar em crianças e adolescentes
Introduction: Hyperlordosis can cause several degenerative spinal pathologies in children and adolescents.
Objective: Determine whether body mass index, age and sexual maturation predict the occurrence of hyperlordosis in children and adolescents. Method: The study analyzed 380 students aged between 10 and 18 years. Body mass index was evaluated using the reference values suggested by the Fitnessgram test battery, and sexual maturation through Tannerâs scale of self-assessed pubic hair growth. Postural assessment was conducted using the DIPA photogrammetry method, version 3.1. (Digital Image Based Postural Assessment) The SPSS 24.0 program was used to analyze the data, and the following statistical tests were applied: chi squared, Mann-Whitney, Fisherâs exact and binary logistic regression. Results: There was statistical significance between hyperlordosis, girlsâ age and puberty in boys (p 0.05). Conclusion: The girlsâ age and boysâ stage of puberty were associated with the occurrence of hyperlordosis.Introdução: A Hiperlordose lombar pode ocasionar diversas patologias degenerativas na coluna vertebral de crianças e adolescentes. Objetivo: Identificar se o Ăndice de Massa Corporal, a Idade e a Maturação Sexual sĂŁo previsores da ocorrĂȘncia da hiperlordose lombar em crianças e adolescentes. MĂ©todo: O estudo analisou 380 estudantes entre 10 e 18 anos. O Ăndice de Massa Corporal foi avaliado por meio dos valores de referĂȘncia sugeridos pela bateria de testes Fitnessgram e a maturação sexual por meio da auto-avaliação da pilosidade pubiana de Tanner. A avaliação postural foi realizada pelo mĂ©todo de fotogrametria DIPA versĂŁo 3.1. (Avaliação Postural Baseada em Imagem Digital). Para anĂĄlise dos dados foi utilizado o programa SPSS 24.0, tendo sido aplicados os testes estatĂsticos: Qui-Quadrado, Mann Whitney, Exato de Fisher e RegressĂŁo LogĂstica BinĂĄria. Resultados: Observou-se que houve significĂąncia estatĂstica entre a Hiperlordose lombar e a idade das meninas e a puberdade dos meninos (p0,05). ConclusĂŁo: A idade das meninas e a puberdade dos meninos foi associada Ă ocorrĂȘncia da hiperlordose lombar.This study was funded by CIEC (Center for
Investigations in Childhood Studies), Strategic Project
UID/CED/00317/2013, via National FCT (Science and
Technology Foundation) funds and co-funded by the
European Regional Development Fund (FEDER), via
COMPETE 2020 â Competitivity and Internalization
Operational Program (POCI) under reference number
POCI-01-0145-FEDER-007562
Four simple recommendations to encourage best practices in research software [version 1; referees: awaiting peer review]
Scientific research relies on computer software, yet software is not always developed following practices that ensure its quality and sustainability. This manuscript does not aim to propose new software development best practices, but rather to provide simple recommendations that encourage the adoption of existing best practices. Software development best practices promote better quality software, and better quality software improves the reproducibility and reusability of research. These recommendations are designed around Open Source values, and provide practical suggestions that contribute to making research software and its source code more discoverable, reusable and transparent. This manuscript is aimed at developers, but also at organisations, projects, journals and funders that can increase the quality and sustainability of research software by encouraging the adoption of these recommendations.
Keyword
Rules for Growth: Promoting Innovation and Growth Through Legal Reform
The United States economy is struggling to recover from its worst economic downturn since the Great Depression. After several huge doses of conventional macroeconomic stimulus - deficit-spending and monetary stimulus - policymakers are understandably eager to find innovative no-cost ways of sustaining growth both in the short and long runs. In response to this challenge, the Kauffman Foundation convened a number of Americaâs leading legal scholars and social scientists during the summer of 2010 to present and discuss their ideas for changing legal rules and policies to promote innovation and accelerate U.S. economic growth. This meeting led to the publication of Rules for Growth: Promoting Innovation and Growth Through Legal Reform, a comprehensive and groundbreaking volume of essays prescribing a new set of growth-promoting policies for policymakers, legal scholars, economists, and business men and women. Some of the top Rules include: âą Reforming U.S. immigration laws so that more high-skilled immigrants can launch businesses in the United States. âą Improving university technology licensing practices so university-generated innovation is more quickly and efficiently commercialized. âą Moving away from taxes on income that penalize risk-taking, innovation, and employment while shifting toward a more consumption-based tax system that encourages saving that funds investment. In addition, the research tax credit should be redesigned and made permanent. âą Overhauling local zoning rules to facilitate the formation of innovative companies. âą Urging judges to take a more expansive view of flexible business contracts that are increasingly used by innovative firms. âą Urging antitrust enforcers and courts to define markets more in global terms to reflect contemporary realities, resist antitrust enforcement from countries with less sound antitrust regimes, and prohibit industry trade protection and subsidies. âą Reforming the intellectual property system to allow for a post-grant opposition process and address the large patent application backlog by allowing applicants to pay for more rapid patent reviews. âą Authorizing corporate entities to form digitally and use software as a means for setting out agreements and bylaws governing corporate activities. The collective essays in the book propose a new way of thinking about the legal system that should be of interest to policymakers and academic scholars alike. Moreover, the ideas presented here, if embodied in law, would augment a sustained increase in U.S. economic growth, improving living standards for U.S. residents and for many in the rest of the world
Practical recipes for the model order reduction, dynamical simulation, and compressive sampling of large-scale open quantum systems
This article presents numerical recipes for simulating high-temperature and
non-equilibrium quantum spin systems that are continuously measured and
controlled. The notion of a spin system is broadly conceived, in order to
encompass macroscopic test masses as the limiting case of large-j spins. The
simulation technique has three stages: first the deliberate introduction of
noise into the simulation, then the conversion of that noise into an equivalent
continuous measurement and control process, and finally, projection of the
trajectory onto a state-space manifold having reduced dimensionality and
possessing a Kahler potential of multi-linear form. The resulting simulation
formalism is used to construct a positive P-representation for the thermal
density matrix. Single-spin detection by magnetic resonance force microscopy
(MRFM) is simulated, and the data statistics are shown to be those of a random
telegraph signal with additive white noise. Larger-scale spin-dust models are
simulated, having no spatial symmetry and no spatial ordering; the
high-fidelity projection of numerically computed quantum trajectories onto
low-dimensionality Kahler state-space manifolds is demonstrated. The
reconstruction of quantum trajectories from sparse random projections is
demonstrated, the onset of Donoho-Stodden breakdown at the Candes-Tao sparsity
limit is observed, a deterministic construction for sampling matrices is given,
and methods for quantum state optimization by Dantzig selection are given.Comment: 104 pages, 13 figures, 2 table
An environment for sustainable research software in Germany and beyond: current state, open challenges, and call for action
Research software has become a central asset in academic research. It optimizes existing and enables new research methods, implements and embeds research knowledge, and constitutes an essential research product in itself. Research software must be sustainable in order to understand, replicate, reproduce, and build upon existing research or conduct new research effectively. In other words, software must be available, discoverable, usable, and adaptable to new needs, both now and in the future. Research software therefore requires an environment that supports sustainability.
Hence, a change is needed in the way research software development and maintenance are currently motivated, incentivized, funded, structurally and infrastructurally supported, and legally treated. Failing to do so will threaten the quality and validity of research. In this paper, we identify challenges for research software sustainability in Germany and beyond, in terms of motivation, selection, research software engineering personnel, funding, infrastructure, and legal aspects. Besides researchers, we specifically address political and academic decision-makers to increase awareness of the importance and needs of sustainable research software practices. In particular, we recommend strategies and measures to create an environment for sustainable research software, with the ultimate goal to ensure that software-driven research is valid, reproducible and sustainable, and that software is recognized as a first class citizen in research. This paper is the outcome of two workshops run in Germany in 2019, at deRSE19 - the first International Conference of Research Software Engineers in Germany - and a dedicated DFG-supported follow-up workshop in Berlin
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