In the optical measuring apparatus based on the TV camera,the image distortion usually occurs due to the defects of optical system design and manufacture or the distortion of the image *** the common barrel distortion...
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In the optical measuring apparatus based on the TV camera,the image distortion usually occurs due to the defects of optical system design and manufacture or the distortion of the image *** the common barrel distortion and pincushion distortion,this paper proposes an improved distortion correction algorithm based on the equivalent spherical surface,and processes the corrected image with bilinear interpolation,scaling and edge filling *** text uses actual images with barrel distortion and pincushion distortion to conduct an experiment which verifies that the proposed algorithm can not only efficiently correct the spherical distortion in the image,but also can ensure the integrity of its information and frame.
Despite their high cost, High-Brightness LEDs (HBLEDs) have high competitiveness in the market, due to the high efficiency that can be achieved. The efficiency requirement should be completed by means of the voltage c...
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Despite their high cost, High-Brightness LEDs (HBLEDs) have high competitiveness in the market, due to the high efficiency that can be achieved. The efficiency requirement should be completed by means of the voltage conversion stage by performing Power Factor Corrector. In this paper we consider the problem of PFC and output current regulation for a group of HBLEDs by using a Ćuk converter under a Sliding Mode control which must be ultimately implemented by a hysteretic comparator to limit the switching frequency to practical values. However, with a constant hysteresis width, the system exhibits harmful harmonic distortion in the input line current waveform. Therefore, a variable hysteresis window is used thereby avoiding this distortion near the zero crossing of the input current. Using the Ćuk converter under SMC with variable hysteresis window, the converter will be imposed to behave as a Loss Free Resistor (LFR) which acts as an ideal rectifier with very low harmonic distortion and therefore with a power factor near unity.
In this paper a simple solution to obtain a feedback controller from input - output process data is proposed. The method uses the virtual reference structure and the virtual error in order to identify a dynamic compen...
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In this paper a simple solution to obtain a feedback controller from input - output process data is proposed. The method uses the virtual reference structure and the virtual error in order to identify a dynamic compensator (DC) that achieves the derivative behaviour of the controller. The DC, defined as an adaptive filter, achieves a precise and extended compensation of the process dynamics. The controller gain is computed in two ways: either by imposing the gain stability margin, as in the case of processes with significant dead time or with large pole excess, or by imposing the phase stability margin, for other types of processes. Both ways are illustrated in the paper by conclusive case studies.
In this paper, we present a systematic approach based on harmonic balance method to study the entrained oscillations in a class of Goodwin-type oscillator networks forced by external periodic signals consisting of hig...
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In this paper, we present a systematic approach based on harmonic balance method to study the entrained oscillations in a class of Goodwin-type oscillator networks forced by external periodic signals consisting of high order harmonics. First, a necessary condition and a conjecture for entrainment of network oscillations are presented. Next, the authors reveal an estimation for the profile of entrained oscillations in one situation and the monotone dependence of the amplitude and phase shift of entrained oscillations to the external input in other contexts. The theoretical results are then illustrated through some examples including a practical model for circadian rhythm in Neurospora crassa.
We have recently proposed a robustified ratio consensus algorithm which achieves asymptotic convergence to the global average in a distributed fashion in static strongly connected digraphs, despite the possible presen...
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ISBN:
(纸本)9781467360890
We have recently proposed a robustified ratio consensus algorithm which achieves asymptotic convergence to the global average in a distributed fashion in static strongly connected digraphs, despite the possible presence of bounded but otherwise arbitrary delays. In this work, we propose a protocol which reaches asymptotic convergence to the global average in a distributed fashion under possible changes in the underlying interconnection topology (e.g., due to component mobility), as well as time-varying delays that might affect transmissions at different times. More specifically, we extend our previous work to also account for the case where, in addition to arbitrary but bounded delays, we may have time varying communication links. The proposed protocol requires that each component has knowledge of the number of its outgoing links, perhaps with some bounded delay, and that the digraphs formed by the switching communication topologies over a finite time window are jointly strongly connected.
It is very difficult to correctly identify single-phase-to-ground fault (SFG) in distribution system with neutral non-effectively grounded (NNG). A novel travelling wave based singlephase-to-ground protection is propo...
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ISBN:
(纸本)9781849198349
It is very difficult to correctly identify single-phase-to-ground fault (SFG) in distribution system with neutral non-effectively grounded (NNG). A novel travelling wave based singlephase-to-ground protection is proposed in the paper. The polarity of initial transient current and voltage travelling waves are used to identify the fault direction, and power frequency voltages are used to distinguish SFG from phaseto- phase fault to ensure the reliability of the protection. In the paper, wavelet transforms and module maxima theory was adopted to represent the polarity of travelling waves effectively and construct protection algorithm,. The analysis and simulation demonstrate that the protection is valid.
This paper proposes a method for solving robust optimal control problems with modulated uncertainty sets. We consider constrained uncertain linear systems and interpret the uncertainty sets as "robustness margins...
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ISBN:
(纸本)9781467360890
This paper proposes a method for solving robust optimal control problems with modulated uncertainty sets. We consider constrained uncertain linear systems and interpret the uncertainty sets as "robustness margins" or "reserve capacities". In particular, given a certain reward for offering such a reserve capacity, we address the problem of determining the optimal size and shape of the uncertainty set, i.e. how much reserve capacity our system should offer. By assuming polyhedral constraints, restricting the class of the uncertainty sets and using affine decision rules, we formulate a convex program to solve this problem. We discuss several specific families of uncertainty sets, whose respective constraints can be reformulated as linear constraints, second-order cone constraints, or linear matrix inequalities. A numerical example demonstrates our approach.
This study is primarily motivated by biological applications and focuses on the identification of Boolean networks from scarce and noisy data. We consider two Bayesian experimental design scenarios: selection of the o...
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ISBN:
(纸本)9781467360890
This study is primarily motivated by biological applications and focuses on the identification of Boolean networks from scarce and noisy data. We consider two Bayesian experimental design scenarios: selection of the observations under a budget, and input design. The goal is to maximize the mutual information between models and data, that is the ultimate statistical upper bound on the identifiability of a system from empirical data. First, we introduce a method to select which components of the state variable to measure under a budget constraint, and at which time points. Our greedy approach takes advantage of the submodularity of the mutual information, and hence requires only a polynomial number of evaluations of the objective to achieve near-optimal designs. Second, we consider the computationally harder task of designing sequences of input interventions, and propose a likelihood-free approximation method. Exact and approximate design solutions are verified with predictive models of genetic regulatory interaction networks in embryonic development.
Motivated by the fact that bounded variation (often discontinuous) functions frequently appear when studying integral equations that describe physical phenomena, we focus on the existence of bounded variation solution...
Motivated by the fact that bounded variation (often discontinuous) functions frequently appear when studying integral equations that describe physical phenomena, we focus on the existence of bounded variation solutions for Urysohn integral measure driven equations. Due to numerous applications of Urysohn integral equations in various domains, problems of this kind have been extensively studied in literature, under more restrictive assumptions. Our approach concerns the framework of Kurzweil-Stieltjes integration, which allows the occurrence of high oscillatory features on the right hand side of the equation. A discussion about interesting consequences of our main result (given by particular cases of the measure driving the equation) is presented. Finally, we show the generality of our results by investigating two examples of impulsive type problems (from both theoretical and numerical perspective) and giving an application in electronics industry concerning polarization properties of ferroelectric materials.
The RLS estimator is designed to perform the approximate solution of HJB-Riccati Equation in Dual Approximate Dynamic Programming. The main focus of the investigation is the linear dependecy of the RLS regressors vect...
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The RLS estimator is designed to perform the approximate solution of HJB-Riccati Equation in Dual Approximate Dynamic Programming. The main focus of the investigation is the linear dependecy of the RLS regressors vectors that it is assembled with state space vectors. There is a problem, for certain situations the regresors vectors are not a basis.
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