29,635 research outputs found
Toward a computational theory for motion understanding: The expert animators model
Artificial intelligence researchers claim to understand some aspect of human intelligence when their model is able to emulate it. In the context of computer graphics, the ability to go from motion representation to convincing animation should accordingly be treated not simply as a trick for computer graphics programmers but as important epistemological and methodological goal. In this paper we investigate a unifying model for animating a group of articulated bodies such as humans and robots in a three-dimensional environment. The proposed model is considered in the framework of knowledge representation and processing, with special reference to motion knowledge. The model is meant to help setting the basis for a computational theory for motion understanding applied to articulated bodies
Traversal of 3D AI Objects in Virtual Game Worlds
This paper aims to highlight the underlying problem of AI traversal in virtual game worlds. AIrsquos self-awareness as an entity, solely depends on the programmer and hence can run into problems if itrsquos not coded properly. The purpose of this research is to eliminate the various factors involved in the traversal of AI and provide a simple solution to the problem that even a novice would be able to code their AI to move around the terrain of the virtual world or in-game world. By using collisions, objective markers and virtual invisible points, the AI can not only move in a 360-degree direction, but cover sufficient in-game mileage and abstain from traversing in to the lsquodanger zonesrsquo which are aptly titled due to them being inaccessible or missing the collision feature.
The medium of choice to depict the virtual world is Unreal Engine 4. The reason for choosing UE4 is because it has a similar layout to other game engines like Unity and hence migration of code is possible though not without its own trials
Entropy of Rotating Misner String Spacetimes
Using a boundary counterterm prescription motivated by the AdS/CFT
conjecture, I evaluate the energy, entropy and angular momentum of the class of
Kerr-NUT/bolt-AdS spacetimes. As in the non-rotating case, when the NUT charge
is nonzero the entropy is no longer equal to one-quarter of the area due to the
presence of the Misner string. When the cosmological constant is also non-zero,
the entropy is bounded from above.Comment: Revtex, 9 pages, 3 figure
Multiresolution analysis in statistical mechanics. II. The wavelet transform as a basis for Monte Carlo simulations on lattices
In this paper, we extend our analysis of lattice systems using the wavelet
transform to systems for which exact enumeration is impractical. For such
systems, we illustrate a wavelet-accelerated Monte Carlo (WAMC) algorithm,
which hierarchically coarse-grains a lattice model by computing the probability
distribution for successively larger block spins. We demonstrate that although
the method perturbs the system by changing its Hamiltonian and by allowing
block spins to take on values not permitted for individual spins, the results
obtained agree with the analytical results in the preceding paper, and
``converge'' to exact results obtained in the absence of coarse-graining.
Additionally, we show that the decorrelation time for the WAMC is no worse than
that of Metropolis Monte Carlo (MMC), and that scaling laws can be constructed
from data performed in several short simulations to estimate the results that
would be obtained from the original simulation. Although the algorithm is not
asymptotically faster than traditional MMC, because of its hierarchical design,
the new algorithm executes several orders of magnitude faster than a full
simulation of the original problem. Consequently, the new method allows for
rapid analysis of a phase diagram, allowing computational time to be focused on
regions near phase transitions.Comment: 11 pages plus 7 figures in PNG format (downloadable separately
Hawking Radiation of Dirac Particles in a Variable-mass Kerr Space-time
Hawking effect of Dirac particles in a variable-mass Kerr space-time is
investigated by using a method called as the generalized tortoise coordinate
transformation. The location and the temperature of the event horizon of the
non-stationary Kerr black hole are derived. It is shown that the temperature
and the shape of the event horizon depend not only on the time but also on the
angle. However, the Fermi-Dirac spectrum displays a residual term which is
absent from that of Bose-Einstein distribution.Comment: 12 pages in 12pt Revtex, no figure, to appear in Gen. Rel. Grav.
Vol.33, No.7 (2001
Fourth-generation SM imprints in B -> K^*l^+l^- decays with polarized K^*
The implication of the fourth-generation quarks in the B -> K^*l^+l^-
(l=mu,tau) decays, when K^* meson is longitudinally or transversely polarized,
is presented. In this context, the dependence of the branching ratio with
polarized K^* and the helicity fractions (f_{L,T}) of K^* meson are studied. It
is observed that the polarized branching ratios as well as helicity fractions
are sensitive to the NP parameters, especially when the final state leptons are
tauons. Hence the measurements of these observables at LHC can serve as a good
tool to investigate the indirect searches of new physics beyond the Standard
Model.Comment: 13 pages, 10 figures, V2: some of the graphs are modified according
to the new data from recent experiments. arXiv admin note: substantial text
overlap with arXiv:1107.569
Multiple phase-coherent laser pulses in optical spectroscopy. II. Applications to multilevel systems
The effects of intense laser pulse trains in coupled multilevel systems (such as pure or mixed molecular crystals) are analyzed by calculating exact density matrix evolutions. It is shown that two‐level approximations are inadequate. The contributions of exchange couplings, inhomogeneous broadening, permanent multipole interactions and transition multipole interactions to absorption and photon echo line shapes are calculated. The absorption line shape of 1,4‐dibromonaphthalene (DBN) is shown to be predominantly an isotopic substitution effect, as our Monte Carlo results give quantitative agreement with experiment for this model. Average t‐matrix approximations to the Green’s function, which have been used to propose a different mechanism for the DBN line shape are shown to be qualitatively inadequate. Dipole–dipole interactions are shown to be an important photon echo decay mechanism in mixed crystals, with the relative importance of permanent and transition multipole interactions dependent on the resonance frequency distribution. Multiple pulse trains, including multiple pulse echoes and optical multiple‐quantum sequences, are shown to be capable of distinguishing different types of interactions in the molecular Hamiltonian and reducing optical density effects. Specific pulse sequences are proposed and their effects are calculated
Optical multiple pulse sequences for multiphoton selective excitation and enhancement of forbidden transitions
In this paper we present novel and simple pulse sequences for enhancing the intensity of forbidden or highly nonresonant optical transitions. These sequences provide a straightforward approach to circumventing the most serious limitation of optical coherent transientspectroscopy: Available laser intensities are often insufficient to excite a significant fraction of the ground state population into desired excited states, either because of large inhomogeneous broadening or, in the case of multiphoton absorption, large anharmonicities. Optical phase modulation (which can be produced by an acousto‐optic modulator) or amplitude modulation (which can be produced by an interferometer) with carefully chosen pulse flip angles and delays can effectively remove even very large energy mismatches, thus permitting essentially complete population inversions arbitrarily far from resonance. Coherent averaging theory and computer calculations are used to derive particularly valuable sequences. Pumping enhancement of 10^3–10^5 (depending on individual molecular parameters) for these modulated pulse sequences are predicted. Specific applications to multiphoton pumping of local vibrational modes are discussed
Complementarity of Semileptonic to and Decays in the Standard Model with Fourth Generation
The decays are
analyzed in the Standard Model extended to fourth generation of quarks (SM4).
The decay rate, forward-backward asymmetry, lepton polarization asymmetries and
the helicity fractions of the final state meson are obtained
using the form factors calculated in the light cone sum rules (LCSR) approach.
We have utilized the constraints on different fourth generation parameters
obtained from the experimental information on , and decays and from
the electroweak precision data to explore their impact on the decay. We find that the values of above mentioned
physical observables deviate deviate significantly from their minimal SM
predications. We also identify a number of correlations between various
observables in and decays. Therefore a combined analysis of these two
decays will compliment each other in the searches of SM4 effects in flavor
physics.Comment: 28 pages, 12 figure
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