190 research outputs found
Nonlinear Model Predictive Controller Design for Identified Nonlinear Parameter Varying Model
In this paper, a novel nonlinear model predictive controller (MPC) is proposed based on an identified nonlinear parameter varying (NPV) model. First, an NPV model scheme is present for process identification, which is featured by its nonlinear hybrid Hammerstein model structure and varying model parameters. The hybrid Hammerstein model combines a normalized static artificial neural network with a linear transfer function to identify general nonlinear systems at each fixed working point. Meanwhile, a model interpolating philosophy is utilized to obtain the global model across the whole operation domain. The NPV model considers both the nonlinearity of transition dynamics due to the variation of the working-point and the nonlinear mapping from the input to the output at fixed working points. Moreover, under the new NPV framework, the control action is computed via a multistep linearization method aimed for nonlinear optimization problems. In the proposed scheme, only low cost tests are needed for system identification and the controller can achieve better output performance than MPC methods based on linear parameter varying (LPV) models. Numerical examples validate the effectiveness of the proposed approach
ΠΠ»ΠΈΡΠ½ΠΈΠ΅ Π΄ΠΎΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΈΡ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΉ Π½Π° ΡΠ΄Π²ΠΈΠΆΠ΅Π½ΠΈΠ΅ Π·Π΅ΠΌΠ½ΠΎΠΉ ΠΏΠΎΠ²Π΅ΡΡ Π½ΠΎΡΡΠΈ Π½Π°Π΄ ΠΎΡΠΈΡΡΠ½ΠΎΠΉ Π²ΡΡΠ°Π±ΠΎΡΠΊΠΎΠΉ
Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΌΠ°ΡΠΊΡΠ΅ΠΉΠ΄Π΅ΡΡΠΊΠΈΡ
ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ Π³ΠΎΡΠΈΠ·ΠΎΠ½ΡΠ°Π»ΡΠ½ΡΡ
ΡΠΌΠ΅ΡΠ΅Π½ΠΈΠΉ ΡΠ΅ΠΏΠ΅ΡΠΎΠ² Π½Π°Π±Π»ΡΠ΄Π°ΡΠ΅Π»ΡΠ½ΡΡ
ΡΡΠ°Π½ΡΠΈΠΉ Π½Π°Π΄ ΠΎΡΠΈΡΡΠ½ΡΠΌΠΈ Π²ΡΡΠ°Π±ΠΎΡΠΊΠ°ΠΌΠΈ ΡΠ°Ρ
Ρ ΠΠ°ΠΏΠ°Π΄Π½ΠΎΠ³ΠΎ ΠΠΎΠ½Π±Π°ΡΡΠ°. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π½Π° Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΌ ΡΠ΄Π°Π»Π΅Π½ΠΈΠΈ ΠΎΡ Π³ΡΠ°Π½ΠΈΡ ΠΌΡΠ»ΡΠ΄Ρ ΠΈΠΌΠ΅ΡΡ ΠΌΠ΅ΡΡΠΎ ΠΌΠ°Π»ΡΠ΅ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ, ΠΊΠΎΡΠΎΡΡΠ΅ Π² ΡΡΠΌΠΌΠ΅ ΠΏΡΠΈΠ²ΠΎΠ΄ΡΡ ΠΊ Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΡΠΌ ΡΠ΄Π²ΠΈΠΆΠ΅Π½ΠΈΡΠΌ Π½Π°Π±Π»ΡΠ΄Π°Π΅ΠΌΡΡ
ΡΠΎΡΠ΅ΠΊ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ. ΠΡΠΈ ΡΠ΄Π²ΠΈΠΆΠ΅Π½ΠΈΡ Π΄ΠΎΡΡΠΈΠ³Π°ΡΡ 20-30% ΠΎΡ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΡΡ
ΡΠ΄Π²ΠΈΠΆΠ΅Π½ΠΈΠΉ Π² ΠΌΡΠ»ΡΠ΄Π΅
Toward a direct measurement of the cosmic acceleration: The first observation of HI 21cm absorption line at FAST
In this work, we report the first result from the investgation of Neutral
atomic hydrogen(HI) 21cm absorption line in spectrum of PKS1413+135 as a
associated type at redshift observed by FAST using the
observing time of 10 minutes for the absorber and the spectral resolution of
the raw data was setted to 10 Hz. The full spectral profile is analysed by
fitting the absorption line with single Gaussian function as the resolution of
10kHz in 2MHz bandwidth, eventually intending to illustrate the latest cosmic
acceleration by the direct measurement of time evolution of the redshift of HI
21cm absorption line with Hubble flow toward a same background Quasar in the
time interval of more than a decade or many years as a detectable signal that
produced by the accelerated expansion of the Universe in the era of FAST at low
redshift space,namely redshift drift or SL effect. The obtained HI
gas column density of this DLA
system, much equivalent to the originally observed value within the uncertainties of the spin
temperature of a spiral host galaxy, and the signal to noise ratio SNR highly
reaching 57.4357 for the resolution of 10kHz evidently validates the
opportunities of the HI 21cm absorption lines of DLA systems to enforce the
awareness of the physical motivation of dark energy by the probe of
with the enhancement of accuracy in the level of
per decade.Comment: 26 pages,8 figures, 3 tables, submitted to JCA
Domain-Guided Conditional Diffusion Model for Unsupervised Domain Adaptation
Limited transferability hinders the performance of deep learning models when
applied to new application scenarios. Recently, Unsupervised Domain Adaptation
(UDA) has achieved significant progress in addressing this issue via learning
domain-invariant features. However, the performance of existing UDA methods is
constrained by the large domain shift and limited target domain data. To
alleviate these issues, we propose DomAin-guided Conditional Diffusion Model
(DACDM) to generate high-fidelity and diversity samples for the target domain.
In the proposed DACDM, by introducing class information, the labels of
generated samples can be controlled, and a domain classifier is further
introduced in DACDM to guide the generated samples for the target domain. The
generated samples help existing UDA methods transfer from the source domain to
the target domain more easily, thus improving the transfer performance.
Extensive experiments on various benchmarks demonstrate that DACDM brings a
large improvement to the performance of existing UDA methods.Comment: Work in progres
How Do Test Takers Interact With Simulation-Based Tasks? A Response-Time Perspective
Many traditional educational assessments use multiple-choice items and constructed-response items to measure fundamental skills. Virtual performance assessments, such as game- or simulation-based assessments, are designed recently in the field of educational measurement to measure more integrated skills through the test takersβ interactive behaviors within an assessment in a virtual environment. This paper presents a systematic timing study based on data collected from a simulation-based task designed recently at Educational Testing Service. The study is intended to understand the response times in complex simulation-based tasks so as to shed light on possible ways of leveraging response time information in designing, assembling, and scoring of simulation-based tasks. To achieve this objective, a series of five analyses were conducted to first understand the statistical properties of the timing data, and then investigate the relationship between the timing patterns and the test takersβ performance on the items/task, demographics, motivation level, personality, and test-taking behaviors through use of different statistical approaches. We found that the five analyses complemented each other and revealed different useful timing aspects of this test-taker sampleβs behavioral features in the simulation-based task. The findings were also compared with notable existing results in the literature related to timing data
Nonlinear Dynamics of a PI Hydroturbine Governing System with Double Delays
A PI hydroturbine governing system with saturation and double delays is generated in small perturbation. The nonlinear dynamic behavior of the system is investigated. More precisely, at first, we analyze the stability and Hopf bifurcation of the PI hydroturbine governing system with double delays under the four different cases. Corresponding stability theorem and Hopf bifurcation theorem of the system are obtained at equilibrium points. And then the stability of periodic solution and the direction of the Hopf bifurcation are illustrated by using the normal form method and center manifold theorem. We find out that the stability and direction of the Hopf bifurcation are determined by three parameters. The results have great realistic significance to guarantee the power system frequency stability and improve the stability of the hydropower system. At last, some numerical examples are given to verify the correctness of the theoretical results
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