2,328 research outputs found
A Generative Model For Zero Shot Learning Using Conditional Variational Autoencoders
Zero shot learning in Image Classification refers to the setting where images
from some novel classes are absent in the training data but other information
such as natural language descriptions or attribute vectors of the classes are
available. This setting is important in the real world since one may not be
able to obtain images of all the possible classes at training. While previous
approaches have tried to model the relationship between the class attribute
space and the image space via some kind of a transfer function in order to
model the image space correspondingly to an unseen class, we take a different
approach and try to generate the samples from the given attributes, using a
conditional variational autoencoder, and use the generated samples for
classification of the unseen classes. By extensive testing on four benchmark
datasets, we show that our model outperforms the state of the art, particularly
in the more realistic generalized setting, where the training classes can also
appear at the test time along with the novel classes
Stagnation point flow of a MHD Powell-Eyring fluid over a nonlinearly stretching sheet in the presence of heat source/sink
This study investigates the stagnation point flow of a MHD Powell-Eyring fluid over a nonlinearly stretching sheet in the presence of heat source/sink. Similarity transformations are used to convert highly non-linear partial differential equations into ordinary differential equations. The transformed nonlinear boundary layer equations are then solved numerically using Keller Box method. The effects of various physical parameters on the dimensionless velocity and temperature profiles are depicted graphically. Present results are compared with previously published work and the results are found to be in very good agreement. Numerical results for local skin-friction and local Nusselt number are tabulated for different physical parameters
The dynamics and control of large flexible space structures-IV
The effects of solar radiation pressure as the main environmental disturbance torque were incorporated into the model of the rigid orbiting shallow shell and computer simulation results indicate that within the linear range the rigid modal amplitudes are excited in proportion to the area to mass ratio. The effect of higher order terms in the gravity-gradient torque expressions previously neglected was evaluated and found to be negligible for the size structures under consideration. A graph theory approach was employed for calculating the eigenvalues of a large flexible system by reducing the system (stiffness) matrix to lower ordered submatrices. The related reachability matrix and term rank concepts are used to verify controllability and can be more effective than the alternate numerical rank tests. Control laws were developed for the shape and orientation control of the orbiting flexible shallow shell and numerical results presented
The dynamics and control of large flexible space structures, part 7
A preliminary Eulerian formulation of the in-plane dynamics of the proposed spacecraft control laboratory experiment configuration is undertaken when the mast is treated as a cantilever type beam and the reflector as a lumped mass at the end of the beam. Frequency and mode shapes are obtained for the open loop model of the beam system and the stability of closed loop control systems is analyzed by both frequency and time domain techniques. Environmental disturbances due to solar radiation pressure are incorporated into models of controlled large flexible orbiting platforms. Thermally induced deformations of simple beam and platform type structures are modelled and expressions developed for the disturbance torques resulting from the interaction of solar radiation pressure. Noise effects in the deterministic model of the hoop/column antenna system are found to cause a degradation in system performance. Appropriate changes in the ratio of plant noise to the measurement noise and/or changes in the control weighting matrix elements can improve transient and steady state performance
Epidemiology of ChiVMV and loss assessment in capsicum (Capsicum annum var. grossum Sendt)
The survey was conducted during rabi season (2021) to determine the incidence of mosaic disease of capsicum in major capsicum growing districts namely, Chikkaballapura, Kolar, Bengaluru rural and Ramanagar. The per cent incidence of mosaic disease based on symptoms in field was recorded, highest in Ramanagar (54.85%) and the least incidence of mosaic disease was observed in Chikkaballapura (26.85%). Transmission and host range studies under glasshouse conditions revealed that ChiVMV is transmitted mechanically. Among 16 host plants tested, 7 plant species (Nicotiana tabacum cv. Samsun, N. glutinosa, N. occidentalis, Datura metel, Physalis floridana, S. nigrum, Capsicum annum) were infected with the Chilli veinal mottle virus disease and the symptom could be seen in 20-25 days. The per cent transmission of ChiVMV by aphid Aphis gossypii was studied. The results showed that ChiVMV can be transmitted by A. gossypii. However, five aphids per plant showed highest per cent transmission (100%). The effect of different dates of inoculation on different plant growth parameters was also studied, the highest per cent disease transmission was observed in T1: Inoculation 15 days after sowing (100.00%)
The dynamics and control of large flexible space structures, 3. Part A: Shape and orientation control of a platform in orbit using point actuators
The dynamics, attitude, and shape control of a large thin flexible square platform in orbit are studied. Attitude and shape control are assumed to result from actuators placed perpendicular to the main surface and one edge and their effect on the rigid body and elastic modes is modelled to first order. The equations of motion are linearized about three different nominal orientations: (1) the platform following the local vertical with its major surface perpendicular to the orbital plane; (2) the platform following the local horizontal with its major surface normal to the local vertical; and (3) the platform following the local vertical with its major surface perpendicular to the orbit normal. The stability of the uncontrolled system is investigated analytically. Once controllability is established for a set of actuator locations, control law development is based on decoupling, pole placement, and linear optimal control theory. Frequencies and elastic modal shape functions are obtained using a finite element computer algorithm, two different approximate analytical methods, and the results of the three methods compared
The Stability of Strange Star Crusts and Strangelets
We construct strangelets, taking into account electrostatic effects,
including Debye screening, and arbitrary surface tension sigma of the interface
between vacuum and quark matter. We find that there is a critical surface
tension sigma_crit below which large strangelets are unstable to fragmentation
and below which quark star surfaces will fragment into a crystalline crust made
of charged strangelets immersed in an electron gas. We derive a
model-independent relationship between sigma_crit and two parameters that
characterize any quark matter equation of state. For reasonable model equations
of state, we find sigma_crit typically of order a few MeV/fm^2. If sigma <=
sigma_crit, the size-distribution of strangelets in cosmic rays could feature a
peak corresponding to the stable strangelets that we construct.Comment: 11 pages, LaTe
Classification of Solutions of Non-homogeneous Non-linear Second Order Neutral Delay Dynamic Equations with Positive and Negative Coefficients
In this paper we have studied the non-homogeneous non-linear second order neutral delay dynamic equations with positive and negative coefficients of the form classified all solutions of this type equations and obtained conditions for the existence or non-existence of solutions into four classes and these four classes are mutually disjoint. Examples are included to illustrate the validation of the main results
Evaluating the Gapless Color-Flavor Locked Phase
In neutral cold quark matter that is sufficiently dense that the strange
quark mass M_s is unimportant, all nine quarks (three colors; three flavors)
pair in a color-flavor locked (CFL) pattern, and all fermionic quasiparticles
have a gap. We recently argued that the next phase down in density (as a
function of decreasing quark chemical potential mu or increasing strange quark
mass M_s) is the new ``gapless CFL'' (``gCFL'') phase in which only seven
quasiparticles have a gap, while there are gapless quasiparticles described by
two dispersion relations at three momenta. There is a continuous quantum phase
transition from CFL to gCFL quark matter at M_s^2/mu approximately equal to
2*Delta, with Delta the gap parameter. Gapless CFL, like CFL, leaves unbroken a
linear combination "Q-tilde" of electric and color charges, but it is a
Q-tilde-conductor with gapless Q-tilde-charged quasiparticles and a nonzero
electron density. In this paper, we evaluate the gapless CFL phase, in several
senses. We present the details underlying our earlier work which showed how
this phase arises. We display all nine quasiparticle dispersion relations in
full detail. Using a general pairing ansatz that only neglects effects that are
known to be small, we perform a comparison of the free energies of the gCFL,
CFL, 2SC, gapless 2SC, and 2SCus phases. We conclude that as density drops,
making the CFL phase less favored, the gCFL phase is the next spatially uniform
quark matter phase to occur. A mixed phase made of colored components would
have lower free energy if color were a global symmetry, but in QCD such a mixed
phase is penalized severely.Comment: 18 pages, RevTeX; Version to appear in Phys Rev D. Minor rewording,
references adde
- …