| 1. |
- Hu, Xiaoming
(författare)
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Input-output behavior for stable linear systems
- 2001
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Ingår i: Journal of the Franklin Institute. - 0016-0032 .- 1879-2693. ; 338:4, s. 497-507
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a controllable, observable, asymptotically stable, finite-dimensional linear system is considered. The input-output problem considered is whether the input in a fairly general class of Hilbert spaces will produce the output in the same class. The problem in this generality appears to be very difficult and in this paper a large class of Hilbert spaces is determined for which the result is true and a series of counter examples are given to the more obvious conjectures.
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| 2. |
- Norinder, Harald
(författare)
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Lightning currents and their variations
- 1935
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Ingår i: Journal of the Franklin Institute. - 0016-0032 .- 1879-2693. ; 220:1, s. 69-92
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Norinder, Harald
(författare)
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On the nature of lightning discharges
- 1934
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Ingår i: Journal of the Franklin Institute. - 0016-0032 .- 1879-2693. ; 218:6, s. 717-738
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Norinder, Harald
(författare)
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The relation between lighting discharges and atmospherics in radio receiving
- 1936
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Ingår i: Journal of the Franklin Institute. - 0016-0032 .- 1879-2693. ; 221:5, s. 585-611
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Tidskriftsartikel (refereegranskat)abstract
- In order to examine the relations between lightning discharges and atmospherics cathode ray oscillographs were applied to record the variation forms of atmospherics. By simultaneous observations of atmospherics, by the aid of the loud speakers of radio receiving sets and corresponding records by cathode ray oscillographs the existence of two characteristic variation forms of atmospherics in connection with thunderstorms were obtained, (a) “the clicks”-singular discharges of a comparatively short duration (up to some hundred microseconds) and caused by shorter local sparks, (b) “the grinders” whistling or hissing perturbation forms in the loud speakers. The corresponding oscillograms resulted in complicated variation forms of the same type as the Author had observed to be usual in ordinary lightning discharges. The relation to lightning was further investigated in an indirect manner. By cathode ray oscillographic records atmospherics of ordinary types with their centres of origin at greater distances from the locality of observations were examined. These atmospherics showed in most cases very characteristic variation forms with more or less pronounced and superimposed periodic or quasiperiodic variation. The main problem was how to explain the generation of these variation forms from known discharges as they were observed at the most probable centres of emission—e.g. lightning paths. For that purpose the transmission equation for radio waves was applied on such discharge variation forms which had been observed to be usual in partial lightning discharges. From the calculation it was concluded that atmospherics with typical variations could be derived from lightning discharges with known and uncomplicated variation forms fixed by cathode ray oscillographic recording. The sometimes apparently complicated variation forms of atmospherics of the short variation type were thus in the most cases found to be a secondary effect caused by gradual deformation during transmission.
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| 5. |
- Alanwar, Amr, et al.
(författare)
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Distributed set-based observers using diffusion strategies
- 2023
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Ingår i: Journal of the Franklin Institute. - : Elsevier BV. - 0016-0032 .- 1879-2693. ; 360:10, s. 6976-6993
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Tidskriftsartikel (refereegranskat)abstract
- We propose two distributed set-based observers using strip-based and set-propagation approaches for linear discrete-time dynamical systems with bounded modeling and measurement uncertainties. Both algorithms utilize a set-based diffusion step, which decreases the estimation errors and the size of estimated sets, and can be seen as a lightweight approach to achieve partial consensus between the distributed estimated sets. Every node shares its measurement with its neighbor in the measurement update step. In the diffusion step, the neighbors intersect their estimated sets using our novel lightweight zonotope intersection technique. A localization example demonstrates the applicability of our algorithms.
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| 6. |
- Ashyralyev, Allaberen, et al.
(författare)
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Taylor's decomposition on four points for solving third-order linear time-varying systems
- 2009
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Ingår i: Journal of the Franklin Institute. - : Elsevier BV. - 0016-0032 .- 1879-2693. ; 346:7, s. 651-662
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Tidskriftsartikel (refereegranskat)abstract
- In the present paper, the use of three-step difference schemes generated by Taylor's decomposition on four points for the numerical solutions of third-order time-varying linear dynamical systems is presented. The method is illustrated for the numerical analysis of an up-converter used in communication systems.
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| 7. |
- Guinaldo, M., et al.
(författare)
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Distributed event-triggered control for non-reliable networks
- 2014
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Ingår i: Journal of the Franklin Institute. - : Elsevier BV. - 0016-0032 .- 1879-2693. ; 351:12, s. 5250-5273
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a distributed event-based control approach to cope with communication delays and packet losses affecting a networked dynamical system. Two network protocols are proposed to deal with these communication effects. The stability of the system is analyzed for constant and time-dependent trigger functions, showing that asymptotic stability can be achieved with the latter design, and this also guarantees a lower bound for the inter-event times. Analytical expressions for the delay bound and the maximum number of consecutive packet losses are derived for different scenarios. Finally, the results are illustrated through a simulation example.
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| 8. |
- Ibarra, Luis, et al.
(författare)
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Adaptive SMC based on the dynamic containment of the sliding variable
- 2021
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Ingår i: Journal of the Franklin Institute. - : Elsevier. - 0016-0032 .- 1879-2693. ; 358:2, s. 1422-1447
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Tidskriftsartikel (refereegranskat)abstract
- Conventional Sliding Mode Controllers (SMCs) exhibit a robust performance against matched bounded uncertainties and disturbances by containing them under a fixed controller's effort. Consequently, the controller is commonly found excessive, leading to chattering and straining the actuator. As a solution, the variable-gain SMCs adapt to the instantaneous system requirements, thus attenuating the aforesaid effects and keeping the SMC's benefits. However, the reported adaptive laws underlying such behavior commonly require arbitrary design considerations and do not consider practical implementation. Unlikely, in this work, a hysteresis-based adaptability law to drive the sliding variable to a boundary layer around zero is proposed. The sliding boundary-hysteresis' width-will consistently "bounce" over the sliding variable, trying to shrink against it while preserving the sliding mode. This behavior finds its steady-state once the sliding variable and the sliding boundary's dynamics are synchronized, with no need of subjective or arbitrary adjustments. The close-loop tuning can be derived from the system's parameters alone, and its steady-state performance can be quantitatively predicted. Furthermore, a method to adjust the sliding surface parameters according to the system's desired behavior is provided, all in a closed, analytical way. Finally, the physical actuator limits are taken into account and never exceeded, and the discrete nature of the devices normally used for SMC implementation is incorporated throughout. Two examples are studied to portray the proposal's advantages.
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| 9. |
- Johansson, Rolf, et al.
(författare)
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Observer-based strictly positive real (SPR) variable structure output feedback control
- 2016
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Ingår i: Journal of the Franklin Institute. - : Elsevier. - 0016-0032 .- 1879-2693. ; 353:16, s. 4213-4232
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Tidskriftsartikel (refereegranskat)abstract
- This paper considers switching output feedback control of linear systems and variable-structure systems. Theory for stability analysis and design for a class of observer-based feedback control systems is presented. A circle-criterion approach can be used to design an observer-based state feedback control which yields a closed-loop system with specified robustness characteristics. The approach is relevant for variable structure system design with preservation of stability when switching feedback control or sliding mode control is introduced in the feedback loop. It is shown that there exists a Lyapunov function valid over the total operating range and this Lyapunov function has also interpretation as a storage function of passivity-based control. The Lyapunov function can be found by solving a Lyapunov equation, which also generates variable structure switching surfaces. Important applications are to be found in variable structure systems with high robustness requirements.
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| 10. |
- Lin, Peng, et al.
(författare)
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A new approach to average consensus problems with multiple time-delays and jointly-connected topologies
- 2012
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Ingår i: Journal of the Franklin Institute. - : Elsevier BV. - 0016-0032 .- 1879-2693. ; 349:1, s. 293-304
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Tidskriftsartikel (refereegranskat)abstract
- This paper investigates average consensus problem in networks of continuous-time agents with delayed information and jointly-connected topologies. A lemma is derived by extending the Barbalat's Lemma to piecewise continuous functions, which provides a new analysis approach for switched systems. Then based on this lemma, a sufficient condition in terms of linear matrix inequalities (LMIs) is given for average consensus of the system by employing a Lyapunov approach, where the communication structures vary over time and the corresponding graphs may not be connected. Finally, simulation results are provided to demonstrate the effectiveness of our theoretical results.
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