979 research outputs found
Hamilton-Jacobi quantization of singular Lagrangians with linear velocities
In this paper, constrained Hamiltonian systems with linear velocities are
investigated by using the Hamilton-Jacobi method. We shall consider the
integrablity conditions on the equations of motion and the action function as
well in order to obtain the path integral quantization of singular Lagrangians
with linear velocities.Comment: late
Effects of heating treatment on some of the physical properties of varnish layers applied on various wood species
The aim of the current study is to determine the effects of different heat treatment and varnish combination applications on some of the physical properties of wood materials sampled from limba (Terminalia superba), iroko (Chlorophora excelsa), ash (Fraxinus excelsior L.) and Anatolian chestnut (Castenea sativa Mill.) species. The heat treatment was applied at two levels (150 and 180°C) for both 3 and 6 h period. Once heat treatment was conducted, four types of varnish layers (cellulose lacquer, synthetic varnish, polyurethane varnish and water based varnish) were applied to the materials. After the treatments application, color, brightness and surface roughness of varnish film layers of the treated woods were measured. The effects of heat treatment and varnish combination applications on the earlier mentioned variables were analyzed according to the study design (factorial design with 4 (species) x 2 (heat) x 2 (duration) x 4 (varnish) = 64 experimental units). For significant analysis of variance (ANOVA) , Duncan mean separation test was performed to separate the interaction combinations. Results of the study indicated that surface roughness increased on wood samples for all four wood species treated with cellulose lacquer and synthetic varnish and across all heating treatments. However, surface roughness decreased for all wood species depending on heating temperature and time. As such, the value of brightness also decreased for all four wood species across all the treatment combinations. The results obtained from the upper surface of the enforcement process are thought to contribute to the national economy.Key words: Heating treatment, cellulose lacquer varnish, synthetic varnish, polyurethane varnish, water based varnish, surface roughness, brightness, color changes
A Novel Method for Epileptic Seizure Detection Using Coupled Hidden Markov Models
We propose a novel Coupled Hidden Markov Model to detect epileptic seizures
in multichannel electroencephalography (EEG) data. Our model defines a network
of seizure propagation paths to capture both the temporal and spatial evolution
of epileptic activity. To address the intractability introduced by the coupled
interactions, we derive a variational inference procedure to efficiently infer
the seizure evolution from spectral patterns in the EEG data. We validate our
model on EEG aquired under clinical conditions in the Epilepsy Monitoring Unit
of the Johns Hopkins Hospital. Using 5-fold cross validation, we demonstrate
that our model outperforms three baseline approaches which rely on a classical
detection framework. Our model also demonstrates the potential to localize
seizure onset zones in focal epilepsy.Comment: To appear in MICCAI 2018 Proceeding
Multi Hamilton-Jacobi quantization of O(3) nonlinear sigma model
The O(3) non-linear sigma model is investigated using multi Hamilton-Jacobi
formalism. The integrability conditions are investigated and the results are in
agreement with those obtained by Dirac's method. By choosing an adequate
extension of phase space we describe the transformed system by a set of three
Hamilton-Jacobi equations and calculate the corresponding action.Comment: 10 pages, LaTeX, to be published in Mod. Phys. Lett.
Weakly-supervised mesh-convolutional hand reconstruction in the wild
We introduce a simple and effective network architecture for monocular 3D hand pose estimation consisting of an image encoder followed by a mesh convolutional decoder that is trained through a direct 3D hand mesh reconstruction loss. We train our network by gathering a large-scale dataset of hand action in YouTube videos and use it as a source of weak supervision. Our weakly-supervised mesh convolutions-based system largely outperforms state-of-the-art methods, even halving the errors on the in the wild benchmark. The dataset and additional resources are available at https://arielai.com/mesh_hands
Effects of antimitotic agents on haploid plant production from unpollinated ovules of sugar beet (beta vulgaris l.)
The effects of antimicrotubule agents on haploid embryo formation from unpollinated ovules of sugar beet (Beta vulgaris L.) were investigated. The antimitotic agent colchicine (at 100 and 150 mg/l) and trifluralin (at 5.0 mg/l) increased the frequency of haploid embryo formation whereas pronamide (at 76.9 and 128.2 mg/l) and trifluralin (at 3.4 mg/l) decreased. Ovules that were non-treated with antimicrotuble agents (i.e., ovules of the control treatment) produced higher percentages of haploid embryos (4.25 %) when compared to the pronamide and trifluralin at 3.4 mg/l concentration. Toxic effects of these agents on embryo formation from ovules were evident. A significant genotypic variation among the lines used was observed. The line M4 produced the highest yield with a mean of 14.71% haploid embryo production while the line M2 producing no embryos at all
BLSM: A Bone-Level Skinned Model of the Human Mesh
We introduce BLSM, a bone-level skinned model of the human body mesh where bone scales are set prior to template synthesis, rather than the common, inverse practice. BLSM first sets bone lengths and joint angles to specify the skeleton, then specifies identity-specific surface variation, and finally bundles them together through linear blend skinning. We design these steps by constraining the joint angles to respect the kinematic constraints of the human body and by using accurate mesh convolution-based networks to capture identity-specific surface variation.
We provide quantitative results on the problem of reconstructing a collection of 3D human scans, and show that we obtain improvements in reconstruction accuracy when comparing to a SMPL-type baseline. Our decoupled bone and shape representation also allows for out-of-box integration with standard graphics packages like Unity, facilitating full-body AR effects and image-driven character animation. Additional results and demos are available from the project webpage: http://arielai.com/blsm
Tracking and regulation control of a 2-DOF robot arm with unbalance
Servomechanism synthesis for a two degree-of-freedom robot arm assembled on a vessel and affected from sea disturbances is considered. Dynamic equations of the robot arm with unbalance and of an approximate base disturbance model are derived. Direct linear controller synthesis based on a linearized model is then studied. It is shown that, although the plant model is nonlinear, linear controller that is synthesized based on the "internal model principle" provide good performance and perform better than the commonly used PID controllers. © 2012 IEEE
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