23,463 research outputs found
Identification of nonlinear lateral flow immunoassay state-space models via particle filter approach
This is the post-print of the Article. The official published version can be accessed from the link below - Copyright @ 2012 IEEEIn this paper, the particle filtering approach is used, together with the kernel smoothing method, to identify the state-space model for the lateral flow immunoassay through available but short time-series measurement. The lateral flow immunoassay model is viewed as a nonlinear dynamic stochastic model consisting of the equations for the biochemical reaction system as well as the measurement output. The renowned extended Kalman filter is chosen as the importance density of the particle filter for the purpose of modeling the nonlinear lateral flow immunoassay. By using the developed particle filter, both the states and parameters of the nonlinear state-space model can be identified simultaneously. The identified model is of fundamental significance for the development of lateral flow immunoassay quantification. It is shown that the proposed particle filtering approach works well for modeling the lateral flow immunoassay.This work was supported in part by the International Science and Technology
Cooperation Project of China under Grant 2009DFA32050, Natural Science Foundation of China under Grants 61104041, International Science and Technology Cooperation Project of Fujian Province of China under Grant
2009I0016
A hybrid EKF and switching PSO algorithm for joint state and parameter estimation of lateral flow immunoassay models
This is the post-print version of the Article. The official published can be accessed from the link below - Copyright @ 2012 IEEEIn this paper, a hybrid extended Kalman filter (EKF) and switching particle swarm optimization (SPSO) algorithm is proposed for jointly estimating both the parameters and states of the lateral flow immunoassay model through available short time-series measurement. Our proposed method generalizes the well-known EKF algorithm by imposing physical constraints on the system states. Note that the state constraints are encountered very often in practice that give rise to considerable difficulties in system analysis and design. The main purpose of this paper is to handle the dynamic modeling problem with state constraints by combining the extended Kalman filtering and constrained optimization algorithms via the maximization probability method. More specifically, a recently developed SPSO algorithm is used to cope with the constrained optimization problem by converting it into an unconstrained optimization one through adding a penalty term to the objective function. The proposed algorithm is then employed to simultaneously identify the parameters and states of a lateral flow immunoassay model. It is shown that the proposed algorithm gives much improved performance over the traditional EKF method.This work was supported in part by the International Science and Technology Cooperation Project of China under Grant
2009DFA32050, Natural Science Foundation of China under Grants 61104041, International Science and Technology Cooperation Project of Fujian Province of China under Grant
2009I0016
Inference of nonlinear state-space models for sandwich-type lateral flow immunoassay using extended Kalman filtering
Copyright [2011] 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.In this paper, a mathematical model for sandwichtype lateral flow immunoassay is developed via short available time series. A nonlinear dynamic stochastic model is considered that consists of the biochemical reaction system equations and the observation equation. After specifying the model structure, we apply the extend Kalman filter (EKF) algorithm for identifying both the states and parameters of the nonlinear state-space model. It is shown that the EKF algorithm can accurately identify the parameters and also predict the system states in the nonlinear dynamic stochastic model through an iterative procedure by using a small number of observations. The identified mathematical model provides a powerful tool for testing the system hypotheses and also inspecting the effects from various design parameters in a both rapid and inexpensive way. Furthermore, by means of the established model, the dynamic changes of the concentration of antigens and antibodies can be predicted, thereby making it possible for us to analyze, optimize and design the properties of lateral flow immunoassay devices.This work was supported in part by the International Science and Technology
Cooperation Project of China under Grant 2009DFA32050, Natural Science Foundation of Fujian Province of China under Grants 2009J01280 and 2009J01281
Classical Poisson structures and r-matrices from constrained flows
We construct the classical Poisson structure and -matrix for some finite
dimensional integrable Hamiltonian systems obtained by constraining the flows
of soliton equations in a certain way. This approach allows one to produce new
kinds of classical, dynamical Yang-Baxter structures. To illustrate the method
we present the -matrices associated with the constrained flows of the
Kaup-Newell, KdV, AKNS, WKI and TG hierarchies, all generated by a
2-dimensional eigenvalue problem. Some of the obtained -matrices depend only
on the spectral parameters, but others depend also on the dynamical variables.
For consistency they have to obey a classical Yang-Baxter-type equation,
possibly with dynamical extra terms.Comment: 16 pages in LaTe
Magnetic-field induced resistivity minimum with in-plane linear magnetoresistance of the Fermi liquid in SrTiO3-x single crystals
We report novel magnetotransport properties of the low temperature Fermi
liquid in SrTiO3-x single crystals. The classical limit dominates the
magnetotransport properties for a magnetic field perpendicular to the sample
surface and consequently a magnetic-field induced resistivity minimum emerges.
While for the field applied in plane and normal to the current, the linear
magnetoresistance (MR) starting from small fields (< 0.5 T) appears. The large
anisotropy in the transverse MRs reveals the strong surface interlayer
scattering due to the large gradient of oxygen vacancy concentration from the
surface to the interior of SrTiO3-x single crystals. Moreover, the linear MR in
our case was likely due to the inhomogeneity of oxygen vacancies and oxygen
vacancy clusters, which could provide experimental evidences for the unusual
quantum linear MR proposed by Abrikosov [A. A. Abrikosov, Phys. Rev. B 58, 2788
(1998)].Comment: 5 pages, 4 figure
Heavy Quark Potentials in Some Renormalization Group Revised AdS/QCD Models
We construct some AdS/QCD models by the systematic procedure of GKN. These
models reflect three rather different asymptotics the gauge theory beta
functions approach at the infrared region,
and , where is the 't Hooft coupling constant.
We then calculate the heavy quark potentials in these models by holographic
methods and find that they can more consistently fit the lattice data relative
to the usual models which do not include the renormalization group improving
effects. But only use the lattice QCD heavy quark potentials as constrains, we
cannot distinguish which kind of infrared asymptotics is the better one.Comment: comparisons with lattice results, qualitative consideration of
quantum corrections are added. (accepted by Phys. Rev. D
Naturalistic Affective Expression Classification by a Multi-Stage Approach Based on Hidden Markov Models
In naturalistic behaviour, the affective states of a person
change at a rate much slower than the typical rate at which video or
audio is recorded (e.g. 25fps for video). Hence, there is a high probability
that consecutive recorded instants of expressions represent a same
affective content. In this paper, a multi-stage automatic affective expression
recognition system is proposed which uses Hidden Markov Models
(HMMs) to take into account this temporal relationship and finalize the
classification process. The hidden states of the HMMs are associated
with the levels of affective dimensions to convert the classification problem
into a best path finding problem in HMM. The system was tested on
the audio data of the Audio/Visual Emotion Challenge (AVEC) datasets
showing performance significantly above that of a one-stage classification
system that does not take into account the temporal relationship, as well
as above the baseline set provided by this Challenge. Due to the generality
of the approach, this system could be applied to other types of
affective modalities
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