We study the problem of minimizing the dominant eigenvalue of an essentially-nonnegative matrix with respect to a trace-preserving or fixed-trace diagonal perturbation, in the case where only a subset of the diagonal ...
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ISBN:
(纸本)9781479978878
We study the problem of minimizing the dominant eigenvalue of an essentially-nonnegative matrix with respect to a trace-preserving or fixed-trace diagonal perturbation, in the case where only a subset of the diagonal entries can be perturbed. The spectrum of the perturbed matrix at the optimum is characterized. A constructive algorithm for computing the optimal diagonal trace-preserving perturbation is developed, using the spectral result together with line-sum-symmetrization arguments. A number of graph-theoretic results are developed on the optimal perturbation and how it changes if further entries are contrained, in part using properties of the Perron complement of nonnegative matrices.
This paper revisits the problem of estimating the domain of attraction of a saturated system with an algebraic loop. A piecewise quadratic Lyapunov function of an augmented state vector composing of the system state a...
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This paper revisits the problem of estimating the domain of attraction of a saturated system with an algebraic loop. A piecewise quadratic Lyapunov function of an augmented state vector composing of the system state and the saturated input has been proposed for use in estimating the domain of attraction for a saturated system. Considering the relationship between the system states and the saturation function, we propose in this paper a generalized piecewise quadratic Lyapunov function, which results from adding a term that characterizes the regional sector condition of the saturated input to the piecewise quadratic Lypunov function. The matrix associated with the generalized piecewise quadratic Lyapunov function is not required to be positive definite, and thus a set of less conservative stability conditions are established, from which a larger estimate of the domain of attraction can be obtained. Simulation results indicate that the effectiveness and superiority of the proposed method.
This paper discusses a model that predicts trap counts of Culex tarsalis, a female mosquito that is responsible for West Nile Virus (WNV) using machine-learning algorithms. Culex mosquitoes are the main transmission v...
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ISBN:
(纸本)9781509041725
This paper discusses a model that predicts trap counts of Culex tarsalis, a female mosquito that is responsible for West Nile Virus (WNV) using machine-learning algorithms. Culex mosquitoes are the main transmission vectors for WNV infections. In this research, a Partial Least Square Regression (PLSR) has been deployed to predict mosquito trap counts of Culex tarsalis using historical meteorological and trap count data from 2005-2015. The associations between 10 years of mosquito capture data and the time lagged environmental quantities trap counts, rainfall, temperature, precipitation, and relative humidity were used to generate a predictive model for the population dynamics of this vector species. Statistical measure of Mean Absolute Error (MAE) is compared with other existing actual collected trap counts to analyze accuracy the predictive models. The paper also details the development of a user-friendly web-interface containing interactive web pages that allow users to visualize the North Dakota mosquito population, weather pattern, and WNV incidence data. The interface utilizes multi-layered Google Maps developed through Google Fusion Tables. An understanding of historical data and weather variables is essential for providing sufficient lead time to predict WNV occurrence, and for implementing disease control and prevention strategies such as spray period and hiring of seasonal mosquito workers. Further, an approach similar to the proposed approach of this paper, which involves the integration of data mining and data visualization techniques, brings novelty to vector control initiatives.
As the shortcomings of multi-rigid-body mathematical modeling for permanent magnetic spherical motor (PMSM), such as the complexities vary greatly and even lead to considerable deviations from the actual system. A nov...
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ISBN:
(纸本)9781479984671
As the shortcomings of multi-rigid-body mathematical modeling for permanent magnetic spherical motor (PMSM), such as the complexities vary greatly and even lead to considerable deviations from the actual system. A novel physical modeling method and dynamic simulation based on computer software are proposed in this paper. Firstly, the physical model of PMSM rotor was set up in Solidworks. And then, the dynamic model was imported in ADAMS. Dynamic simulation considering the friction and the gravity or not was analyzed respectively. The results offer a reliable approach for the subsequent closed-loop control about PMSM, as well as in-depth study of its dynamic characteristics.
This paper addresses the problem of localization of multiple odor sources using a mobile robot in a time-variant airflow environment, and provides a mapping method which uses the Dempster-Shafer (D-S) theory to reason...
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This paper addresses the problem of localization of multiple odor sources using a mobile robot in a time-variant airflow environment, and provides a mapping method which uses the Dempster-Shafer (D-S) theory to reason the possible locations of several odor sources. In the proposed method, the robot carries out the D-S inference and iteratively updates a grid map in which each cell has two states (i.e., occupied by an odor source, and not occupied by odor source), using the successive measurements from a gas sensor and an anemometer when the robot is cruising in the given search area. Considering the fact that in outdoor environments air almost always flow and vary with time, estimated air-mass paths are used to construct the belief mass functions of the D-S inference. Here the air-mass path is defined as the trajectory most likely taken by an air mass encountered with the mobile robot in a time-varying airflow environment, and an air mass can contain odor molecules and bring them to the robot, or not contain odor molecule and just pass by the robot. Simulations are carried out and the results in a time-variant airflow environment show that the locations of the multiple odor sources can be mapped online with the proposed method.
with a two-compartment model, we investigate how subthreshold sinusoidal electric fields(EFs) affect neuronal discharges of active neurons by adjusting the field intensity and the field frequency. It's found that ...
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ISBN:
(纸本)9781467374439
with a two-compartment model, we investigate how subthreshold sinusoidal electric fields(EFs) affect neuronal discharges of active neurons by adjusting the field intensity and the field frequency. It's found that apparent fluctuations on neuronal discharges only appear within several stimulus frequency windows. And when the field frequency is adjusted to be close to the multiple of the intrinsic spiking rate, the fluctuations are maximized. Compared with the change in neuronal spiking rate, the modulation of neuronal spike timing induced by subthreshold EFs is stronger. Additionally, field effects on neuronal discharges are enhanced by the increasing stimulus intensity. Our results provide useful guidance to understand how subthreshold sinusoidal EFs modulate neuronal discharges, which may help to improve the future electromagnetic therapy.
The analysis of the eddy current loss in the permanent magnet (PM) is an important research topic of the PM motor. PM eddy current loss in PMSM with fractional-slot concentrated winding (FSCW), which has ample harmoni...
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ISBN:
(纸本)9781479984671
The analysis of the eddy current loss in the permanent magnet (PM) is an important research topic of the PM motor. PM eddy current loss in PMSM with fractional-slot concentrated winding (FSCW), which has ample harmonics exist in the air gap field, is an urgent problem needed to be solved. A FSCW-PMSM with 24-slot-16-pole two-dimensional model of PM eddy current loss is established by using the finite element method (FEM). The motor winding MMF and harmonic of air gap flux density is analyzed. According to the mathematical model of PM eddy current loss, this paper has calculated the main space harmonics loss generated on one PM. Under the rated-load condition, the influencing factors of PM eddy current loss are analyzed. From the above analysis this paper has adopted effective methods to reduce the PM eddy current loss.
The purpose of this work is to calculate Surge and Swab pressure in oil wells with eccentricity between drill string and wellbore or casing string. Analysis of this phenomenon, in which the fluid is confined between t...
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ISBN:
(纸本)9781509023219
The purpose of this work is to calculate Surge and Swab pressure in oil wells with eccentricity between drill string and wellbore or casing string. Analysis of this phenomenon, in which the fluid is confined between two eccentric cylinders, are made. The conformal mapping is used to lead the eccentric domain into the concentric domain, since the usual models correspond to concentric geometries. The results of this study, using the proposed methodology, are presented and discussed.
At the single neuron level, neural information processing involves the transformation of input stimulation into an output spike train. Here a generalized linear model(GLM is used to reconstruct the mapping from stimul...
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ISBN:
(纸本)9781467374439
At the single neuron level, neural information processing involves the transformation of input stimulation into an output spike train. Here a generalized linear model(GLM is used to reconstruct the mapping from stimulation to firing trains of single neuron for Hudgkin-Huxley(H-H) model. Firstly, H-H model is stimulated by the white noise to generate the input-output data samples used to construct GLM. Then, the parameters of GLM are estimated according to the maximum likelihood of the spike time serial of spike trains extracted from action potential of H-H. After that, the input-output mapping of spike trains evoked by white noise for H-H is successfully reconstructed. Through comparing the inter spike interval(ISI) and Pearson's correlation coefficient, it also proves that the established GLM provides a good reproduction and prediction of the firing information for H-H. These studies provide us a new insight into coding processes and information tansfer of single neural.
Based on the two-compartment neuron model, the influence of neuronal morphology on firing and phase response curves(PRC) of cells are investigated. And by means of PRC, the relationship between neuronal morphology and...
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ISBN:
(纸本)9781467374439
Based on the two-compartment neuron model, the influence of neuronal morphology on firing and phase response curves(PRC) of cells are investigated. And by means of PRC, the relationship between neuronal morphology and network synchronization stimulated by extracellular electric field is studied. Results showed that the excitability of neurons can present different types when the morphological parameter is different. Furthermore, the sensitivity of neuronal synchronization to extracellular electric field has big difference for different morphological parameters.
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