10,319 research outputs found
Recommended from our members
Mixed H2/H∞ filtering for uncertain systems with regional pole assignment
Copyright [2005] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.The mixed H2/H∞ filtering problem for uncertain linear continuous-time systems with regional pole assignment is considered. The purpose of the problem is to design an uncertainty-independent filter such that, for all admissible parameter uncertainties, the following filtering requirements are simultaneously satisfied: 1) the filtering process is asymptotically stable; 2) the poles of the filtering matrix are located inside a prescribed region that compasses the vertical strips, horizontal strips, disks, or conic sectors; 3) both the H2 norm and the H∞ norm on the respective transfer functions are not more than the specified upper bound constraints. We establish a general framework to solve the addressed multiobjective filtering problem completely. In particular, we derive necessary and sufficient conditions for the solvability of the problem in terms of a set of feasible linear matrix inequalities (LMIs). An illustrative example is given to illustrate the design procedures and performances of the proposed method
Mixed H2/H∞ filtering for uncertain systems with regional pole assignment
The mixed H2/H∞ filtering problem for uncertain linear continuous-time systems with regional pole assignment is considered. The purpose of the problem is to design an uncertainty-independent filter such that, for all admissible parameter uncertainties, the following filtering requirements are simultaneously satisfied: 1) the filtering process is asymptotically stable; 2) the poles of the filtering matrix are located inside a prescribed region that compasses the vertical strips, horizontal strips, disks, or conic sectors; 3) both the H2 norm and the norm on the respective transfer functions are not more than the specified upper bound constraints. We establish a general framework to solve the addressed multiobjective filtering problem completely. In particular, we derive necessary and sufficient conditions for the solvability of the problem in terms of a set of feasible linear matrix inequalities (LMIs). An illustrative example is given to illustrate the design procedures and performances of the proposed method. © 2005 IEEE.published_or_final_versio
Learning Reasoning Paths over Semantic Graphs for Video-grounded Dialogues
Compared to traditional visual question answering, video-grounded dialogues
require additional reasoning over dialogue context to answer questions in a
multi-turn setting. Previous approaches to video-grounded dialogues mostly use
dialogue context as a simple text input without modelling the inherent
information flows at the turn level. In this paper, we propose a novel
framework of Reasoning Paths in Dialogue Context (PDC). PDC model discovers
information flows among dialogue turns through a semantic graph constructed
based on lexical components in each question and answer. PDC model then learns
to predict reasoning paths over this semantic graph. Our path prediction model
predicts a path from the current turn through past dialogue turns that contain
additional visual cues to answer the current question. Our reasoning model
sequentially processes both visual and textual information through this
reasoning path and the propagated features are used to generate the answer. Our
experimental results demonstrate the effectiveness of our method and provide
additional insights on how models use semantic dependencies in a dialogue
context to retrieve visual cues.Comment: Accepted at ICLR (International Conference on Learning
Representations) 202
Dynamical coupled-channel model of kaon-hyperon interactions
The pi N --> KY and KY --> KY reactions are studied using a dynamical
coupled-channel model of meson-baryon interactions at energies where the baryon
resonances are strongly excited. The channels included are: pi N, K \Lambda,
and K\Sigma. The resonances considered are: N^* [S_{11}(1650), P_{11}(1710),
P_{13}(1720),D_{13}(1700)]; \Delta^* [S_{31}(1900), P_{31}(1910),
P_{33}(1920)]; \Lambda ^* [S_{01}(1670), P_{01}(1810)] \Sigma^* [P_{11}(1660),
D_{13}(1670)]; and K^*(892). The basic non-resonant \pi N --> KY and KY --> KY
transition potentials are derived from effective Lagrangians using a unitary
transformation method. The dynamical coupled-channel equations are simplified
by parametrizing the pi N -->pi N amplitudes in terms of empirical pi N
partial-wave amplitudes and a phenomenological off-shell function. Two models
have been constructed. Model A is built by fixing all coupling constants and
resonance parameters using SU(3) symmetry, the Particle Data Group values, and
results from a constituent quark model. Model B is obtained by allowing most of
the parameters to vary around the values of model A in fitting the data. Good
fits to the available data for pi^- p to K^0 \Lambda, K^0 \Sigma^0 have been
achieved. The investigated kinematics region in the center-of-mass frame goes
from threshold to 2.5 GeV. The constructed models can be imbedded into
associated dynamical coupled-channel studies of kaon photo- and
electro-production reactions.Comment: 35 pages, 11 Figure
Poincar\'e gauge theory with even and odd parity dynamic connection modes: isotropic Bianchi cosmological models
The Poincar\'e gauge theory of gravity has a metric compatible connection
with independent dynamics that is reflected in the torsion and curvature. The
theory allows two good propagating spin-0 modes. Dynamical investigations using
a simple expanding cosmological model found that the oscillation of the 0
mode could account for an accelerating expansion similar to that presently
observed. The model has been extended to include a mode and more
recently cross parity couplings. We investigate the dynamics of this model in a
situation which is simple, non-trivial, and yet may give physically interesting
results that might be observable. We consider homogeneous cosmologies, more
specifically, isotropic Bianchi class A models. We find an effective Lagrangian
for our dynamical system, a system of first order equations, and present some
typical dynamical evolution.Comment: 8 pages, 1 figures, submitted to IARD 2010 Conference Proceedings in
{\em Journal of Physics: Conference Series}, eds. L. Horwitz and M. Land
(2011
Cosmo MSW effect for mass varying neutrinos
We consider neutrinos with varying masses which arise in scenarios relating
neutrino masses to the dark energy density in the universe. We point out that
the neutrino mass variation can lead to level crossing and thus a cosmo MSW
effect, having dramatic consequences for the flavor ratio of astrophysical
neutrinos.Comment: 8 pages, 1 figure, more detailed discussions, version to be published
by Mod. Phys. Lett.
Evidence of early multi-strange hadron freeze-out in high energy nuclear collisions
Recently reported transverse momentum distributions of strange hadrons
produced in Pb(158AGeV) on Pb collisions and corresponding results from the
relativistic quantum molecular dynamics (RQMD) approach are examined. We argue
that the experimental observations favor a scenario in which multi-strange
hadrons are formed and decouple from the system rather early at large energy
densities (around 1 GeV/fm). The systematics of the strange and non-strange
particle spectra indicate that the observed transverse flow develops mainly in
the late hadronic stages of these reactions.Comment: 4 pages, 4 figure
Multimodal Transformer Networks for End-to-End Video-Grounded Dialogue Systems
Developing Video-Grounded Dialogue Systems (VGDS), where a dialogue is
conducted based on visual and audio aspects of a given video, is significantly
more challenging than traditional image or text-grounded dialogue systems
because (1) feature space of videos span across multiple picture frames, making
it difficult to obtain semantic information; and (2) a dialogue agent must
perceive and process information from different modalities (audio, video,
caption, etc.) to obtain a comprehensive understanding. Most existing work is
based on RNNs and sequence-to-sequence architectures, which are not very
effective for capturing complex long-term dependencies (like in videos). To
overcome this, we propose Multimodal Transformer Networks (MTN) to encode
videos and incorporate information from different modalities. We also propose
query-aware attention through an auto-encoder to extract query-aware features
from non-text modalities. We develop a training procedure to simulate
token-level decoding to improve the quality of generated responses during
inference. We get state of the art performance on Dialogue System Technology
Challenge 7 (DSTC7). Our model also generalizes to another multimodal
visual-grounded dialogue task, and obtains promising performance. We
implemented our models using PyTorch and the code is released at
https://github.com/henryhungle/MTN.Comment: Accepted at ACL 2019 (Long Paper
- …