5,983 research outputs found
Efficient MaxCount and threshold operators of moving objects
Calculating operators of continuously moving objects presents some unique challenges, especially when the operators involve aggregation or the concept of congestion, which happens when the number of moving objects in a changing or dynamic query space exceeds some threshold value. This paper presents the following six d-dimensional moving object operators: (1) MaxCount (or MinCount), which finds the Maximum (or Minimum) number of moving objects simultaneously present in the dynamic query space at any time during the query time interval. (2) CountRange, which finds a count of point objects whose trajectories intersect the dynamic query space during the query time interval. (3) ThresholdRange, which finds the set of time intervals during which the dynamic query space is congested. (4) ThresholdSum, which finds the total length of all the time intervals during which the dynamic query space is congested. (5) ThresholdCount, which finds the number of disjoint time intervals during which the dynamic query space is congested. And (6) ThresholdAverage, which finds the average length of time of all the time intervals when the dynamic query space is congested. For these operators separate algorithms are given to find only estimate or only precise values. Experimental results from more than 7,500 queries indicate that the estimation algorithms produce fast, efficient results with error under 5%
Zero Mode Effect Generalization for the Electromagnetic Current in the Light Front
We consider in this work the electromagnetic current for a system composed by
two charged bosons and show that it has a structure of many bodies even in the
impulse approximation, when described in the light front time . In terms
of the two-body component for the bound state, the current contains two-body
operators. We discuss the process of pair creation from the interacting photon
and interpret it as a zero mode contribution to the current and its
consequences for the components of currents in the light-front.Comment: 13 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:hep-th/050911
Polynomial Tensor Sketch for Element-wise Function of Low-Rank Matrix
This paper studies how to sketch element-wise functions of low-rank matrices.
Formally, given low-rank matrix A = [Aij] and scalar non-linear function f, we
aim for finding an approximated low-rank representation of the (possibly
high-rank) matrix [f(Aij)]. To this end, we propose an efficient
sketching-based algorithm whose complexity is significantly lower than the
number of entries of A, i.e., it runs without accessing all entries of [f(Aij)]
explicitly. The main idea underlying our method is to combine a polynomial
approximation of f with the existing tensor sketch scheme for approximating
monomials of entries of A. To balance the errors of the two approximation
components in an optimal manner, we propose a novel regression formula to find
polynomial coefficients given A and f. In particular, we utilize a
coreset-based regression with a rigorous approximation guarantee. Finally, we
demonstrate the applicability and superiority of the proposed scheme under
various machine learning tasks
Interpolating Scattering Amplitudes between Instant Form and Front Form of Relativistic Dynamics
Among the three forms of relativistic Hamiltonian dynamics proposed by Dirac
in 1949, the instant form and the front form can be interpolated by introducing
an interpolation angle between the ordinary time and the light-front time
. Using this method, we introduce the interpolating
scattering amplitude that links the corresponding time-ordered amplitudes
between the two forms of dynamics and provide the physical meaning of the
kinematic transformations as they allow the invariance of each individual
time-ordered amplitude for an arbitrary interpolation angle. In particular, it
exhibits that the longitudinal boost is kinematical only in the front form
dynamics, or the light-front dynamics (LFD), but not in any other interpolation
angle dynamics. It also shows that the disappearance of the connected
contributions to the current arising from the vacuum occurs when the
interpolation angle is taken to yield the LFD. Since it doesn't require the
infinite momentum frame (IMF) to show this disappearance and the proof is
independent of reference frames, it resolves the confusion between the LFD and
the IMF. The well-known utility of IMF usually discussed in the instant form
dynamics is now also extended to any other interpolation angle dynamics using
our interpolating scattering amplitudes.Comment: 34 pages, 5 figure
Cooling of Dark-Matter Admixed Neutron Stars with density-dependent Equation of State
We propose a dark-matter (DM) admixed density-dependent equation of state
where the fermionic DM interacts with the nucleons via Higgs portal. Presence
of DM can hardly influence the particle distribution inside neutron star (NS)
but can significantly affect the structure as well as equation of state (EOS)
of NS. Introduction of DM inside NS softens the equation of state. We explored
the effect of variation of DM mass and DM Fermi momentum on the NS EOS.
Moreover, DM-Higgs coupling is constrained using dark matter direct detection
experiments. Then, we studied cooling of normal NSs using APR and DD2 EOSs and
DM admixed NSs using dark-matter modified DD2 with varying DM mass and Fermi
momentum. We have done our analysis by considering different NS masses. Also DM
mass and DM Fermi momentum are varied for fixed NS mass and DM-Higgs coupling.
We calculated the variations of luminosity and temperature of NS with time for
all EOSs considered in our work and then compared our calculations with the
observed astronomical cooling data of pulsars namely Cas A, RX J0822-43, 1E
1207-52, RX J0002+62, XMMU J17328, PSR B1706-44, Vela, PSR B2334+61, PSR
B0656+14, Geminga, PSR B1055-52 and RX J0720.4-3125. It is found that APR EOS
agrees well with the pulsar data for lighter and medium mass NSs but cooling is
very fast for heavier NS. For DM admixed DD2 EOS, it is found that for all
considered NS masses, all chosen DM masses and Fermi momenta agree well with
the observational data of PSR B0656+14, Geminga, Vela, PSR B1706-44 and PSR
B2334+61. Cooling becomes faster as compared to normal NSs in case of
increasing DM mass and Fermi momenta. It is infered from the calculations that
if low mass super cold NSs are observed in future that may support the fact
that heavier WIMP can be present inside neutron stars.Comment: 24 Pages, 15 Figures and 2 Tables. Version accepted in The European
Physical Journal
Application performance of elements in a floating–gate FPAA
Field–programmable analog arrays (FPAAs) provide a method for rapidly prototyping analog systems. Currently available commercial and academic FPAAs are typically based on operational amplifiers (or other similar analog primitives) with only a few computational elements per chip. While their specific architectures vary, their small sizes and often restrictive interconnect designs leave current FPAAs limited in functionality, flexibility, and usefulness. In this paper, we explore the use of floating–gate devices as the core programmable element in a signal processing FPAA. A generic FPAA architecture is presented that offers increased functionality and flexibility in realizing analog systems. In addition, the computational analog elements are shown to be widely and accurately programmable while remaining small in area. 1. LOW–POWER SIGNAL PROCESSING The future of FPAAs lie in their ability to speed the implementatio
Concentrations of Hair Minerals Determined by Inductively Coupled Plasma-Mass Spectrometry in People with Headaches
Calculations were made to determine what relationships exist between headaches and hair mineral levels of 1,995 hair tissue mineral analyses by inductively coupled plasma-mass spectrometry. Of the 1,995 samples (1,089 females, 906 males), 163 (100 females, 63 males) were taken from patients who had been diagnosed with headaches. Above average hair levels of bismuth and the earth metals were found among the both the males and females of the headache group. An age correlation analyses showed highest headache incidence in teens and early forties. A direct correlation was also found between calcium and magnesium levels, which peaked in the late twenties. Further study should be done to determine why these levels are elevated and what can be done to keep them balanced
Religion Information Card
Southern Adventist University\u27s Religion 2019 information brochure.https://knowledge.e.southern.edu/infocards2019/1022/thumbnail.jp
Ancient Egypt 1920 Part 2
Part 2 of the 1920 Ancient Egypt books. Contents include a Mentuhetep statue, varnishes in Theban tombs, the kings of Ethiopia, and Nile boats (continued).https://knowledge.e.southern.edu/kweeks_coll/1011/thumbnail.jp
Lonnie Edwards Oral History
Lonnie Edwards was born in Madison County, Alabama on December 6th 1942. He attended high school at a local school in Madison County. He had basic training at Fort Rally Camp before being sent over to Vietnam. After he came back from Vietnam he went to trade school at JF Drake in Huntsville and worked with PPJN Industries. He married and had children and later got divorced and remarried. They are both retired and living in Madison County
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