28,157 research outputs found
Two monotonic functions involving gamma function and volume of unit ball
In present paper, we prove the monotonicity of two functions involving the
gamma function and relating to the -dimensional volume of the
unit ball in .Comment: 7 page
Monotonicity results and bounds for the inverse hyperbolic sine
In this note, we present monotonicity results of a function involving to the
inverse hyperbolic sine. From these, we derive some inequalities for bounding
the inverse hyperbolic sine.Comment: 3 page
A NEW GENERAL CONCEPTUAL APPROACH TO MODELING THE LIVESTOCK SECTOR: AN APPLICATION TO THE JAPANESE SWINE-PORK SECTOR
Many livestock sector models have limited coverage of relevant variables, and are somewhat ad hoc in their choice of what should be specified as behavioral equations. This study develops a generic conceptual approach to modeling the livestock sector that provides consistent rules of specification and better coverage of variables. This approach is then applied to the swine-pork sector of Japan. The new approach departs significantly from existing models. The structure clearly differentiates stock and flow variables; only flow variables have behavioral specifications and stock variables are accounting identities; flow variables are expressed in rates rather than levels; logistic functions are used in most flow variables to automatically impose biological-technological limits; and swine slaughter number and weight are disaggregated into sow and other swine (i.e., gilt-barrow). The estimated Japanese swine-pork model has good fit, no serial correlation, significant coefficients, correct signs, and is better able to capture both the mean and variability of all endogenous variables.Livestock Production/Industries, Research Methods/ Statistical Methods,
Comparing Kalman Filters and Observers for Power System Dynamic State Estimation with Model Uncertainty and Malicious Cyber Attacks
Kalman filters and observers are two main classes of dynamic state estimation
(DSE) routines. Power system DSE has been implemented by various Kalman
filters, such as the extended Kalman filter (EKF) and the unscented Kalman
filter (UKF). In this paper, we discuss two challenges for an effective power
system DSE: (a) model uncertainty and (b) potential cyber attacks. To address
this, the cubature Kalman filter (CKF) and a nonlinear observer are introduced
and implemented. Various Kalman filters and the observer are then tested on the
16-machine, 68-bus system given realistic scenarios under model uncertainty and
different types of cyber attacks against synchrophasor measurements. It is
shown that CKF and the observer are more robust to model uncertainty and cyber
attacks than their counterparts. Based on the tests, a thorough qualitative
comparison is also performed for Kalman filter routines and observers.Comment: arXiv admin note: text overlap with arXiv:1508.0725
Fluctuations in Number of Cercospora beticola Conidia in Relationship to Environment and Disease Severity in Sugar Beet
All content of Phytopathology is open access without restriction 12 months after publicationCercospora leaf spot, caused by Cercospora beticola, is the most damaging foliar disease of sugar beet in Minnesota (MN) and North Dakota (ND). Research was conducted to characterize the temporal progression of aerial concentration of C. beticola conidia in association with the environment and disease severity in sugar beet. In 2003 and 2004, volumetric spore traps were placed within inoculated sugar beet plots to determine daily dispersal of conidia at Breckenridge, MN, and St. Thomas, ND. Plots were rated weekly for disease severity. At both locations, conidia were first collected in early July 2003 and late June in 2004. Peaks of conidia per cubic meter of air were observed with maxima in late August 2003 and in early September 2004 at both locations. Peaks of airborne conidium concentration were significantly correlated with the average temperature of daily hours when relative humidity was greater than 87%. Weekly mean hourly conidia per cubic meter of air was significantly (P <0.01) associated with disease severity during both years and across locations. This study showed that C. beticola conidial numbers may be used to estimate potential disease severity that, with further research, could be incorporated in a disease forecasting model to rationalize Cercospora leaf spot management.Peer reviewe
Isovector channel of quark-meson-coupling model and its effect on symmetry energy
The non-relativistic approximation of the quark-meson-coupling model has been
discussed and compared with the Skyrme-Hartree-Fock model which includes spin
exchanges. Calculations show that the spin-exchange interaction has important
effect on the descriptions of finite nuclei and nuclear matter through the Fock
exchange. Also in the quark-meson-coupling model, it is the Fock exchange that
leads to a nonlinear density-dependent isovector channel and changes the
density-dependent behavior of the symmetry energy.Comment: 20 pages, 9 figures and 1 table, accepted for publication in Nuclear
Physics
On the Application of Gluon to Heavy Quarkonium Fragmentation Functions
We analyze the uncertainties induced by different definitions of the momentum
fraction in the application of gluon to heavy quarkonium fragmentation
function. We numerically calculate the initial fragmentation
functions by using the non-covariant definitions of with finite gluon
momentum and find that these fragmentation functions have strong dependence on
the gluon momentum . As , these fragmentation
functions approach to the fragmentation function in the light-cone definition.
Our numerical results show that large uncertainties remains while the
non-covariant definitions of are employed in the application of the
fragmentation functions. We present for the first time the polarized gluon to
fragmentation functions, which are fitted by the scheme exploited in
this work.Comment: 11 pages, 7 figures;added reference for sec.
Monotonicity and logarithmic convexity relating to the volume of the unit ball
Let stand for the volume of the unit ball in for
. In the present paper, we prove that the sequence
is logarithmically convex and that the sequence
is strictly
decreasing for . In addition, some monotonic and concave properties of
several functions relating to are extended and generalized.Comment: 12 page
Generating EPR beams in a cavity optomechanical system
We propose a scheme to produce continuous variable entanglement between
phase-quadrature amplitudes of two light modes in an optomechanical system. For
proper driving power and detuning, the entanglement is insensitive with bath
temperature and of mechanical oscillator. Under realistic experimental
conditions, we find that the entanglement could be very large even at room
temperature.Comment: 4.1 pages, 4 figures, comments are welcome; to appear in PRA,
published version with corrections of typo
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