897 research outputs found
CLEAR Space Weather Center of Excellence: All-Clear Solar Energetic Particle Prediction
The CLEAR Space Weather Center of Excellence (CLEAR center) is a five year
project that is funded by the NASA Space Weather Center of Excellence program.
The CLEAR center will build a comprehensive prediction framework for solar
energetic particles (SEPs) focusing on the timely and accurate prediction of
low radiation periods (``all clear forecast") and the occurrence and
characteristics of elevated periods. This will be accomplished by integrating
empirical, first-principles based and machine learning (ML)-trained prediction
models. In this paper, the motivation, overview, and tools of the CLEAR center
will be discussed
Spin-orbit and orbit-orbit strengths for radioactive neutron-rich doubly magic nucleus Sn in relativistic mean field theory
Relativistic mean field (RMF) theory is applied to investigate the properties
of the radioactive neutron-rich doubly magic nucleus Sn and the
corresponding isotopes and isotones. The two-neutron and two-proton separation
energies are well reproduced by the RMF theory. In particular, the RMF results
agree with the experimental single-particle spectrum in Sn as well as
the Nilsson spin-orbit parameter and orbit-orbit parameter thus
extracted, but remarkably differ from the traditional Nilsson parameters.
Furthermore, the present results provide a guideline for the isospin dependence
of the Nilsson parameters.Comment: 4 pages, 4 figures, Phys. Rev. C in pres
Labor Relations Conflict in the Workplace: Scale Development, Consequences and Solutions
Because the goals of employers and employees are often incompatible, conflicts are inevitable and an essential part of organizational life. The three studies reported in this paper addressed the issues of identifying the dimensions of workplace conflicts within organizations, exploring the consequences of conflicts, and finding appropriate methods of conflict resolution. The first study identified and developed three dimensions of labor relations conflict, including interest-based, rights-based, and emotion-based conflicts. The second study explored two sets of individual outcomes of labor relations conflicts and found labor relations conflicts had a negative effect on employee job satisfaction and affective commitment and positive effects on employee turnover intention and counterproductive work behavior. The third study tested the effectiveness of partnership practices as an alternative method of resolving labor relations conflicts. Suggestions are offered for future research on the labor relations conflict dimensions as well as its outcomes and solutions introduced in these studies
Stochastic scheduling of autonomous mobile robots at hospitals
The outbreak of the New Coronavirus has significantly increased the
vulnerability of medical staff. This paper addresses the safety and stress
relief of medical personnel by proposing a solution to the scheduling problem
of autonomous mobile robots (AMRs) in a stochastic environment. Considering the
stochastic nature of travel and service times for AMRs affected by the
surrounding environment, the routes of AMRs are planned to minimize the daily
cost of the hospital (including the AMR fixed cost, penalty cost of violating
the time window, and transportation cost). To efficiently generate high-quality
solutions, we identify several properties and incorporate them into an improved
Tabu Search (I-TS) algorithm for problem-solving. Experimental evaluations
demonstrate that the I-TS algorithm outperforms existing methods by producing
higher-quality solutions. By leveraging the characteristics of medical request
environments, we intelligently allocate an appropriate number of AMRs to
efficiently provide services, resulting in substantial cost reductions for
hospitals and enhanced utilization of medical resources. These findings confirm
the effectiveness of the proposed stochastic programming model in determining
the optimal number of AMRs and their corresponding service routes across
various environmental settings
Microscopic and self-consistent description for neutron halo in deformed nuclei
A deformed relativistic Hartree-Bogoliubov theory in continuum has been
developed for the study of neutron halos in deformed nuclei and the halo
phenomenon in deformed weakly bound nuclei is investigated. Magnesium and neon
isotopes are studied and some results are presented for the deformed
neutron-rich and weakly bound nuclei 44Mg and 36Ne. The core of the former
nucleus is prolate, but the halo has a slightly oblate shape. This indicates a
decoupling of the halo orbitals from the deformation of the core. The generic
conditions for the existence of halos in deformed nuclei and for the occurrence
of this decoupling effect are discussed.Comment: 7 pages, 2 figures; invited talk at the XXXV Brazilian Workshop on
Nuclear Physics, Sep 2-6, 2012, Maresias, Brazi
Halos in a deformed Relativistic Hartree-Bogoliubov theory in continuum
In this contribution we present some recent results about neutron halos in
deformed nuclei. A deformed relativistic Hartree-Bogoliubov theory in continuum
has been developed and the halo phenomenon in deformed weakly bound nuclei is
investigated. These weakly bound quantum systems present interesting examples
for the study of the interdependence between the deformation of the core and
the particles in the halo. Magnesium and neon isotopes are studied and detailed
results are presented for the deformed neutron-rich and weakly bound nuclei
42Mg. The core of this nucleus is prolate, but the halo has a slightly oblate
shape. This indicates a decoupling of the halo orbitals from the deformation of
the core. The generic conditions for the existence of halos in deformed nuclei
and for the occurrence of this decoupling effect are discussed.Comment: 6 pages, 2 figures; invited talk at the 2nd Int. Conf. on Nuclear
Structure & Dynamics (NSD12), Opatija, Croatia, 9-13 July 201
Application of the Monte Carlo Method in Modeling Transport and Acceleration of Solar Energetic Particles
The need for quantitative characterization of the solar energetic particle
(SEP) dynamics goes beyond being an academic discipline only. It has numerous
practical implications related to human activity in space. The terrestrial
magnetic field shields the International Space Station (ISS) and most uncrewed
missions from exposure to SEP radiation. However, extreme SEP events with hard
energy spectra are particularly rich in hundreds of MeV to several GeV protons
that can reach the altitudes of the Low Earth Orbit (LEO). These protons have a
high penetrating capability, thus producing significant radiation hazards for
human spaceflight. SEPs also have a significant effect on the atmosphere.
Sudden ionization of the upper atmosphere at high latitudes that occurs during
polar cap absorption (PCA) events can block high frequency (HF) communication
for hours, affecting communication with aircraft on intercontinental
high-altitude flights. Another effect of SEPs in the atmosphere is creating NOx
molecules in the upper atmosphere that can deplete the atmospheric ozone
population. The paper also presents an analysis of (1) how various pitch angle
diffusion coefficient approximations affect the properties of the simulated
SEPs population and (2) discusses how pitch angle scattering when SEPs are
beyond 1 AU affects a SEP event decay phase at the Earth's orbit
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