11,870 research outputs found
A HYPERBOLIC TANGENT YIELD FUNCTION OF FLORIDA CITRUS
This study models Florida citrus production as a function of the age profile of a given tree stock. The age relationship is estimated using a modified hyperbolic tangent function and the parameters is solved by Spatial Process Models and Maximum Likelihood approach. The estimation is based on the production data of four citrus varieties in 25 regions of Florida from 1992 to 2005. The results show smooth S-shaped yield curves of Florida citrus. This analysis offers yield function of citrus as the first step for statistical modeling of the risks associated with citrus cancers aimed at pricing insurance rates.yield function, citrus, hyperbolic tangent, insurance, spatial autoregressive, Demand and Price Analysis,
Aerodynamics of thrust vectoring
Thrust vectoring as a means to enhance maneuverability and aerodynamic performane of a tactical aircraft is discussed. This concept usually involves the installation of a multifunction nozzle. With the nozzle, the engine thrust can be changed in direction without changing the attitude of the aircraft. Change in the direction of thrust induces a significant change in the aerodynamic forces on the aircraft. Therefore, this device can be used for lift-augmenting as well as stability and control purposes. When the thrust is deflected in the longitudinal direction, the lift force and the pitching stability can be manipulated, while the yawing stability can be controlled by directing the thrust in the lateral direction
Calculation of aerodynamic characteristics of airplane configurations at high angles of attack
Calculation of longitudinal and lateral directional aerodynamic characteristics of airplanes by the VORSTAB code is examined. The numerical predictions are based on the potential flow theory with corrections of high angle of attack phenomena; namely, vortex flow and boundary layer separation effects. To account for the vortex flow effect, vortex lift, vortex action point, augmented vortex lift and vortex breakdown effect through the method of suction analogy are included. The effect of boundary layer separation is obtained by matching the nonlinear section data with the three dimensional lift characteristics iteratively. Through correlation with results for nine fighter configurations, it is concluded that reasonably accurate prediction of longitudinal and static lateral directional aerodynamics can be obtained with the VORSTAB code up to an angle of attack at which wake interference and forebody vortex effect are not important. Possible reasons for discrepancy at higher angles of attack are discussed
Calculation of aerodynamic characteristics at high angles of attack for airplane configurations
The primary objective is to determine how an airplane configuration should be modeled to predict both longitudinal and lateral aerodynamic characteristics at high angles of attack. A generic fighter model, an F-16 and an F-18 configuration with leading edge flap deflection and an F-106B configuration were investigated. Furthermore, the F-16XL and X-29 configurations were examined. Some calculated results are given
Search for Higgs Bosons Decay Using Vector Boson Fusion
The sensitivity of the ATLAS experiment to low mass SM Higgs produced via
Vector Boson Fusion mechanism with is invest igated. A cut
based event selection has been chosen to optimize the expected signal
significance with this decay mode. A signal significance of 2. 2 may
be achieved for M_H=130 \gev with 30 fb of accumulated luminosity
Coherent output of photons from coupled superconducting transmission line resonators controlled by charge qubits
We study the coherent control of microwave photons propagating in a
superconducting waveguide consisting of coupled transmission line resonators,
each of which is connected to a tunable charge qubit. While these coupled line
resonators form an artificial photonic crystal with an engineered photonic band
structure, the charge qubits collectively behave as spin waves in the low
excitation limit, which modify the band-gap structure to slow and stop the
microwave propagation. The conceptual exploration here suggests an
electromagnetically controlled quantum device based on the on-chip circuit QED
for the coherent manipulation of photons, such as the dynamic creation of
laser-like output from the waveguide by pumping the artificial atoms for
population inversion.Comment: 8 pages, 3 figure
Quark charge balance function and hadronization effects in relativistic heavy ion collisions
We calculate the charge balance function of the bulk quark system before
hadronization and those for the directly produced and the final hadron system
in high energy heavy ion collisions. We use the covariance coefficient to
describe the strength of the correlation between the momentum of the quark and
that of the anti-quark if they are produced in a pair and fix the parameter by
comparing the results for hadrons with the available data. We study the
hadronization effects and decay contributions by comparing the results for
hadrons with those for the bulk quark system. Our results show that while
hadronization via quark combination mechanism slightly increases the width of
the charge balance functions, it preserves the main features of these functions
such as the longitudinal boost invariance and scaling properties in rapidity
space. The influence from resonance decays on the width of the balance function
is more significant but it does not destroy its boost invariance and scaling
properties in rapidity space either. The balance functions in azimuthal
direction are also presented.Comment: 9 figure
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