Articoli di riviste: "IOPID CONTROLLER"

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Puangdownreong, Deacha. "Fractional Order PID Controller Design for DC Motor Speed Control System via Flower Pollination Algorithm". ECTI Transactions on Electrical Engineering, Electronics, and Communications 17, n. 1 (9 settembre 2019): 14–23. http://dx.doi.org/10.37936/ecti-eec.2019171.215368.

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Over two decades, the fractional (non-integer) order PID (FOPID or PIλDµ ) controller was introduced and demonstrated to perform the better responses in comparison with the conventional integer order PID (IOPID). In this paper, the design of an optimal FOPID controller for a DC motor speed control system by the flower pollination algorithm (FPA), oneof the most efficient population-based metaheuristic optimization searching techniques, is proposed. Based on the modern optimization framework, five parameters of the FOPID controller are optimized by the FPA to meet the response specifications of the DC motor speed control system and defined as constraint functions. Results obtained by the FOPID controller are compared with those obtained by the IOPID designed by the FPA. As the simulation results show, the FOPID can provide significantly superior speed responses to the IOPID.

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Xin, Rui Hao, Chun Yang Wang, Xue Lian Liu, Ming Qiu Li e Duan Yuan Bai. "Robust Fractional Order Proportional Integral Control for Large Time-Delay System". Applied Mechanics and Materials 716-717 (dicembre 2014): 1614–19. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.1614.

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In this paper, a new control method for large time delay system is proposed. Firstly, the decreasing time delay controller is used to remodel large delay time plant into small delay time plant. Then, a fractional robust proportional-integral controller (FOPI) is designed, using the phase margin and cut-off frequency at a specified point in the Bode plot of flat robust conditions, to guarantee the desired control performance and the robustness of the high order system to the gain order system. For comparison between the fractional order proportional integral controller and the traditional integer order PID (IOPID) controller, the IOPID controller is also designed following the same proposed tuning specifications. The simulation results indicates that the both designed controllers work efficiently. Furthermore, the FOPI controller makes the large time-delay system get better control effect, the system has high robustness, adaptive ability and anti-jamming ability.

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Zaway, Intissar, Rim Jallouli-Khlif, Boutheina Maaleja, Hanene Medhaffar e Nabil Derbela. "Multi-objective Fractional Order PID Controller Optimization for Kid's Rehabilitation Exoskeleton". International Journal of Robotics and Control Systems 3, n. 1 (29 dicembre 2022): 32–49. http://dx.doi.org/10.31763/ijrcs.v3i1.840.

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Fractional order Controllers have been used in several industrial cases to achieve better performance of the systems. This paper proposes a Fractional Order Proportional Integral Derivative (FOPID) controller. It is synthesized using Oustaloup approximation, and its parameters are tuned using the Genetic Algorithm (GA) optimization method. The aim is to minimize the error, the energy and the startup torques using two objective functions to improve the control performances and the robustness. The validity of the proposed controller is shown via simulation by controlling a two-link exoskeleton for children's gait rehabilitation, and the results are compared to an Integer order PID (IOPID) controller. Simulation results clearly indicate the superiority of the optimized FOPID in terms of trajectory tracking and the used torques. Moreover, the FOPID controller is tested with parameter uncertainties. Its robustness is proven against thigh and shank masses variation. Both controllers are simulated under the same frequency conditions using Simulink MATLAB R2018a.

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Junyi, Li, e Qijuan Chen. "Fractional Order Controller Designing with Firefly Algorithm and Parameter Optimization for Hydroturbine Governing System". Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/825608.

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A fractional order PID (FOPID) controller, which is suitable for control system designing for being insensitive to the variation in system parameter, is proposed for hydroturbine governing system in the paper. The simultaneous optimization for several parameters of controller, that is,Ki,Kd,Kp,λ, andμ, is done by a recently developed metaheuristic nature-inspired algorithm, namely, the firefly algorithm (FA), for the first time, where the selecting, moving, attractiveness behavior between fireflies and updating of brightness, and decision range are studied in detail to simulate the optimization process. Investigation clearly reveals the advantages of the FOPID controller over the integer controllers in terms of reduced oscillations and settling time. The present work also explores the superiority of FA based optimization technique in finding optimal parameters of the controller. Further, convergence characteristics of the FA are compared with optimum integer order PID (IOPID) controller to justify its efficiency. What is more, analysis confirms the robustness of FOPID controller under isolated load operation conditions.

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Liu, Yi Duo, Chun Yang Wang, Ming Qiu Li, Cheng Jun Tian e Duan Yuan Bai. "Fuzzy Fractional Order Proportional Integral Controllers for UAV Lateral Attitude Control System". Applied Mechanics and Materials 716-717 (dicembre 2014): 1609–13. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.1609.

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This article is based on the theory of fractional calculus control, and put forward a kind of fractional order PI controller design method for lateral attitude control system of unmanned aerial vehicle (UAV) model. And the unit step response of the control system is analyzed in the simulation to improve the UAV flight control system stability and robustness. Use the controller parameter tuning method and combined with fuzzy reasoning to design IOPID controller, FOPI controller and fuzzy fractional order PI controller. Then, by exploiting Matlab, the frequency domain response and unit step response characteristics of the different control systems can be plotted. The results verified that the designed fuzzy fractional order controller for the attitude control system is effective.

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Cherian, Neenu Elizabeth, e K. Sundaravadivu. "Analytical Design of Fractional Order Proportional Integral Controller for Spherical Tank ". Applied Mechanics and Materials 573 (giugno 2014): 279–84. http://dx.doi.org/10.4028/www.scientific.net/amm.573.279.

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This paper presents an analytical design method for fractional order proportional integral (FOPI) controller for the spherical tank which is modelled as a first order plus dead time (FOPDT) process. The design is based on the Bode’s ideal transfer function and fractional calculus. By using frequency domain, the proposed FOPI tuning rules are directly derived for a generalized first order plus dead time process and then applied to the transfer functions obtained at various operating points of the spherical tank. The performance of the designed FOPI controller is compared with the conventional integer order proportional integral derivative (IOPID) controller in simulation.

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Shi, Lezhen, Xiaodong Miao e Hua Wang. "An improved nonlinear proportional-integral-differential controller combined with fractional operator and symbolic adaptation algorithm". Transactions of the Institute of Measurement and Control 42, n. 5 (31 ottobre 2019): 927–41. http://dx.doi.org/10.1177/0142331219879332.

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Parameter adjustment is usually applied for designing the proportional-integral-differential (PID) controllers. However, the ability to improve control performance by adjusting parameters is limited. Hence, with the goal to achieve ideal closed-loop response, this paper takes advantage of a structural optimization method for modifying the controller model. A symbolic adaptation algorithm for fractional order PID (FOPID) controller is employed to obtain precise nonlinear controller model. Firstly, a modeling comparison for nonlinear duffing system is carried out to highlight the efficiency of the symbolic adaptation algorithm. The case study indicates the proposed algorithm can establish compact dynamic models by amending the shortcomings of symbolic regression. Secondly, the proposed controller is restructured with the linear FOPID controller and its nonlinearity is increased by adjusting controllers’ components in symbolic form. The proposed controllers are simulated in an unstable second-order system, a time-delay system and a nonlinear VanderPol system. Compared with the IOPID and the FOPID controller, the symbolic adaptation algorithm improves the structural flexibility of these linear controllers. Meanwhile, the system response can better approximate the desired response and the structural integrity of the nonlinear controller model is guaranteed simultaneously. Finally, the nonlinear FOPD controllers for trajectory tracking experiments are carried out on a rotary inverted pendulum control system.

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Sowrirajan, CHANDRASEKARAN, DURAIRAJ Sundarraj e PADMAVATHI S. "ENHANCING THE PERFORMANCE OF A PHOTOVOLTAIC-FED MULTILEVEL INVERTER USING A PI HYSTERESIS CONTROLLER". DYNA 97, n. 3 (1 maggio 2022): 321–28. http://dx.doi.org/10.6036/10262.

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In recent years, power quality has become almost as important in the renewable energy sector. Much of today's research is focused on resolving power quality issues. These issues are related to a voltage (sags, swells, distortions, and imbalances), system response speed, harmonics, ripples, and Electromagnetic Interference (EMI). Many researchers have recently been working on various controllers to address power quality issues. These articles primarily address power quality issues that arise as a result of system response time, harmonics, and torque ripples. This study will be used to improve the performance of a photovoltaic (PV) fed multilevel inverter. In the field of renewable energy systems, controllers have played a critical role. Proportional (P), Proportional-Integral (PI), and Proportional Integral Derivative (PID), Fractional Order PID (FOPID), and Integral Order PID (IOPID) controllers are used in renewable energy systems to improve power quality. In this study, the response of the PI controller will be measured, analyzed, and compared to the response of the PI hysteresis controller. Existing methods make use of a photovoltaic-fed multilevel inverter, a boost converter, a multilevel inverter, and a proportional-integral (PI) controller. As a load, a three-phase induction motor is used. A PI hysteresis controller is used in place of a traditional PI controller in the proposed system. For the PI Controller, the Experimental Hardware prototype model is designed and validated. Simulation designs for existing and proposed systems are carried out using MATLAB Simulink, and the results are noted and verified. Keywords: PI controller, Multilevel Inverter (MLI), boost converter, hysteresis controller, ripple reduction, Photovoltaic module.

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Chen, Hao, Wei Xie, Xiyang Chen, Jingang Han, Nadia Aït-Ahmed, Zhibin Zhou, Tianhao Tang e Mohamed Benbouzid. "Fractional-Order PI Control of DFIG-Based Tidal Stream Turbine". Journal of Marine Science and Engineering 8, n. 5 (28 aprile 2020): 309. http://dx.doi.org/10.3390/jmse8050309.

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This study mainly investigates the current and speed control strategies of a doubly-fed induction generator (DFIG), which is applied to a tidal stream turbine (TST). Indeed, DFIG using integer-order PI (IOPI) controller has been widely proposed in the applications with a similar system, especially in wind energy conversion system (WECS). However, these conventional controllers cannot deal with the problems caused by the parameter variations satisfactorily under complex and harsh operation conditions, and may even deteriorate the performance. As a result, a fractional-order PI (FOPI) controller is considered to improve the efficiency and performance of DFIG-based TST in this paper. The FOPI controller, developed from the traditional IOPI controller and the fractional calculus theory, has a lot of prominent merits in many aspects, such as robustness, stability, and dynamic performance. In this paper, the proposed control strategies are embedded into the whole TST model which contains the tidal stream turbine, and the generator. The obtained simulation results demonstrate the prominent effectiveness and advantages of the proposed strategies compared with the conventional IOPI controller in terms of overshoot, static error, adjustment time, and robustness. It implies that FOPI controller could be a good candidate in TST applications.

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Abdulkader, Rasheed. "Controller Design based on Fractional Calculus for AUV Yaw Control". Engineering, Technology & Applied Science Research 13, n. 2 (2 aprile 2023): 10432–38. http://dx.doi.org/10.48084/etasr.5687.

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This research presents a fractional order integral controller strategy, which improves the steering angle for Autonomous Underwater Vehicles (AUVs). The AUV mathematical modeling is presented. A Fractional Order Proportional Integral (FOPI) control scheme is implemented to ensure the yaw angle stability of the AUV steering under system uncertainty. The FOPI controller is validated with MATLAB/Simulink and is compared to the conventional Integer Order PI (IOPI) controller to track the yaw angle of the structure. The simulation results show that the proposed FOPI controller outperforms the IOPI controller and improves the AUV system steering and the overall transient response while ensuring the system's stability with and without external disturbances such as underwater current and different loading conditions.

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Kar, Biprajeet, e Prasanta Roy. "A Comparative Study Between Cascaded FOPI–FOPD and IOPI–IOPD Controllers Applied to a Level Control Problem in a Coupled Tank System". Journal of Control, Automation and Electrical Systems 29, n. 3 (12 marzo 2018): 340–49. http://dx.doi.org/10.1007/s40313-018-0373-z.

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Müller Moreira, Walter Ernest, e Claudio Garcia. "Performance comparison between IOPID and FOPID controllers in an industrial flow pilot plant". IFAC-PapersOnLine 54, n. 4 (2021): 232–37. http://dx.doi.org/10.1016/j.ifacol.2021.10.039.

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O'Connor-Reina, Carlos, Jose Maria Ignacio Garcia, Elisa Rodriguez Ruiz, Maria Del Carmen Morillo Dominguez, Victoria Ignacio Barrios, Peter Baptista Jardin, Juan Carlos Casado Morente, Maria Teresa Garcia Iriarte e Guillermo Plaza. "Myofunctional Therapy App for Severe Apnea–Hypopnea Sleep Obstructive Syndrome: Pilot Randomized Controlled Trial". JMIR mHealth and uHealth 8, n. 11 (9 novembre 2020): e23123. http://dx.doi.org/10.2196/23123.

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Background Myofunctional therapy has demonstrated efficacy in treating sleep-disordered breathing. We assessed the clinical use of a new mobile health (mHealth) app that uses a smartphone to teach patients with severe obstructive sleep apnea–hypopnea syndrome (OSAHS) to perform oropharyngeal exercises. Objective We conducted a pilot randomized trial to evaluate the effects of the app in patients with severe OSAHS. Methods Forty patients with severe OSAHS (apnea–hypoxia index [AHI]>30) were enrolled prospectively and randomized into an intervention group that used the app for 90 sessions or a control group. Anthropometric measures, Epworth Sleepiness Scale (0-24), Pittsburgh Sleep Quality Index (0-21), Iowa Oral Performance Instrument (IOPI) scores, and oxygen desaturation index were measured before and after the intervention. Results After the intervention, 28 patients remained. No significant changes were observed in the control group; however, the intervention group showed significant improvements in most metrics. AHI decreased by 53.4% from 44.7 (range 33.8-55.6) to 20.88 (14.02-27.7) events/hour (P<.001). The oxygen desaturation index decreased by 46.5% from 36.31 (27.19-43.43) to 19.4 (12.9-25.98) events/hour (P=.003). The IOPI maximum tongue score increased from 39.83 (35.32-45.2) to 59.06 (54.74-64.00) kPa (P<.001), and the IOPI maximum lip score increased from 27.89 (24.16-32.47) to 44.11 (39.5-48.8) kPa (P<.001). The AHI correlated significantly with IOPI tongue and lip improvements (Pearson correlation coefficient −0.56 and −0.46, respectively; both P<.001). The Epworth Sleepiness Scale score decreased from 10.33 (8.71-12.24) to 5.37 (3.45-7.28) in the app group (P<.001), but the Pittsburgh Sleep Quality Index did not change significantly. Conclusions Orofacial exercises performed using an mHealth app reduced OSAHS severity and symptoms, and represent a promising treatment for OSAHS. Trial Registration Spanish Registry of Clinical Studies AWGAPN-2019-01, ClinicalTrials.gov NCT04438785; https://clinicaltrials.gov/ct2/show/NCT04438785

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Wang, Xiaogang, e Junhui Cai. "Grid-Connected Inverter Based on a Resonance-Free Fractional-Order LCL Filter". Fractal and Fractional 6, n. 7 (1 luglio 2022): 374. http://dx.doi.org/10.3390/fractalfract6070374.

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The integer-order LCL (IOLCL) filter has excellent high-frequency harmonic attenuation capability but suffers from resonance, which causes system instability in grid-connected inverter applications. This paper studied a class of resonance-free fractional-order LCL (FOLCL) filters and control problems of single-phase FOLCL-type grid-connected inverters (FOGCI). The Caputo fractional calculus operator was used to describe the fractional-order inductor and capacitor. Compared with the conventional IOLCL filter, by reasonably selecting the orders of the inductor and capacitor, the resonance peak of the FOLCL filter could be effectively avoided. In this way, the FOGCI could operate stably without passive or active dampers, which simplified the design of control system. Furthermore, compared with a single-phase integer-order grid-connected inverter (IOGCI) controlled by an integer-order PI (IOPI) controller, the FOGCI, combined with a fractional-order PI (FOPI) controller, could achieve greater gain and phase margins, which improved the system performance. The correctness of the theoretical analyses was validated through both simulation and hardware-in-the-loop experiments.

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Wang, Li, Jian Jun Li, Yuan Yao, Ying Hui Wang e Qing Xiang Guan. "Line-of-Sight Stabilization System Based on Fractional-Order Control". Advanced Materials Research 962-965 (giugno 2014): 2703–7. http://dx.doi.org/10.4028/www.scientific.net/amr.962-965.2703.

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The line-of-sight (LOS) stabilization control is required to isolate LOS from the movement and vibration of carrier and ensure pointing and tracking for target in electro-optical tracking system. In this paper, a fractional-order PI (FOPI) controller is applied in the design of stabilization loop of LOS stabilization system based on the analysis of the fractional calculus theory. This controller exhibits excellent performance even in presence of nonlinearity and uncertainty. Details of this controller along with the performance comparisons between FOPI and conventional integer-order PI (IOPI) are presented. Simulation results indicate that the FOPI controller can improve the carrier disturbance rejection performance of LOS stabilization system.

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Anantachaisilp, Parinya, e Zongli Lin. "Fractional-Order Surge Control of Active Magnetic Bearings Suspended Compressor". Actuators 9, n. 3 (24 agosto 2020): 75. http://dx.doi.org/10.3390/act9030075.

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H∞ surge control in centrifugal compressors by using active magnetic bearings (AMBs) has been successfully designed and implemented. However, the structure and design process of H∞ surge control are quite complex. This paper reports on the design and implementation of fractional-order proportional-derivative control (FOPD) that results in the required specifications of surge control with a simple controller structure. To validate its effectiveness, the proposed FOPD surge controller has been implemented on a centrifugal compressor test rig equipped with AMBs. Simulation and experimental results show that the FOPD surge controller outperforms integer-order PD (IOPD) control in extending the surge limit in terms of the mass flow and provides similar performance as the H∞ controller.

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Wang, Baokun, Shaohua Wang, Yibing Peng, Youguo Pi e Ying Luo. "Design and High-Order Precision Numerical Implementation of Fractional-Order PI Controller for PMSM Speed System Based on FPGA". Fractal and Fractional 6, n. 4 (12 aprile 2022): 218. http://dx.doi.org/10.3390/fractalfract6040218.

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In this paper, the design of a fractional-order proportional integral (FOPI) controller and integer-order (IOPI) controller are compared for the permanent magnet synchronous motor (PMSM) speed regulation system. A high-precision implementation method of a fractional-order proportional integral (FOPI) controller is proposed in this work. Three commonly used numerical implementation methods of fractional operators are investigated and compared for comprehensively evaluating the numerical implementation performance in this work. Furthermore, for the impulse response invariant implementation method, the effects of different discretization orders on the control performance of the system are compared. The high-order fractional-order controller can be implemented accurately in a control system with the field-programmable gate array (FPGA) with the capability of parallel calculation. The simulation and experimental results show that the high-precision numerical implementation method of the designed high-order FOPI controller has better performance than the ordinary precision fractional operation implementation method and traditional order integer order PI controller.

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Park, Jin-Woo, Chi-Hoon Oh, Bo-Un Choi, Ho-Jin Hong, Joong-Hee Park, Tae-Yeon Kim e Yong-Jin Cho. "Effect of Progressive Head Extension Swallowing Exercise on Lingual Strength in the Elderly: A Randomized Controlled Trial". Journal of Clinical Medicine 10, n. 15 (31 luglio 2021): 3419. http://dx.doi.org/10.3390/jcm10153419.

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Lingual strengthening training can improve the swallowing function in older adults, but the optimal method is unclear. We investigated the effects of a new progressive resistance exercise in the elderly by comparing with a conventional isometric tongue strengthening exercise. Twenty-nine participants were divided into two groups randomly. One group performed forceful swallow of 2 mL of water every 10 s for 20 min, and a total of 120 swallowing tasks per session at 80% angle of maximum head extension. The other group performed five repetitions in 24 sets with a 30 s rest, and the target level was settled at 80% of one repetition maximum using the Iowa Oral Performance Instrument (IOPI). A total of 12 sessions were carried out by both groups over a 4-week period. Blinded measurements (for maximum lingual isometric pressure and peak pressure during swallowing) were obtained using IOPI before exercise and at four weeks in both groups. After four weeks, both groups showed a significant improvement in lingual strength involving both isometric and swallowing tasks. However, there was no significant difference between the groups in strength increase involving both tasks. Regardless of the manner, tongue-strengthening exercises substantially improved lingual pressure in the elderly with equal effect.

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Angel, L., e J. Viola. "Design and statistical robustness analysis of FOPID, IOPID and SIMC PID controllers applied to a motor-generator system". IEEE Latin America Transactions 13, n. 12 (dicembre 2015): 3724–34. http://dx.doi.org/10.1109/tla.2015.7404900.

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Grussendorf, M., C. Reiners, R. Paschke e K. Wegscheider. "Reduction of Thyroid Nodule Volume by Levothyroxine and Iodine Alone and in Combination: A Randomized, Placebo-Controlled Trial". Journal of Clinical Endocrinology & Metabolism 96, n. 9 (1 settembre 2011): 2786–95. http://dx.doi.org/10.1210/jc.2011-0356.

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Abstract Context: Nodular goiter is common worldwide, but there is still debate over the medical treatment. Objective: The objective of the study was the measurement of the effect of a treatment with (nonsuppressive) T4, iodine, or a combination of both compared with placebo on volume of thyroid nodules and thyroid. Design: This was a multicenter, randomized, double-blind trial in patients with nodular goiter in Germany [LISA (Levothyroxin und Iodid in der Strumatherapie Als Mono-oder Kombinationstherapie) trial]. Setting: The study was conducted in outpatient clinics in university hospitals and regional hospitals and private practices. Participants: One thousand twenty-four consecutively screened and centrally randomized euthyroid patients aged 18–65 yr with one or more thyroid nodules (minimal diameter 10 mm) participated in the study. Intervention: Intervention included placebo, iodine (I), T4, or T4+I for 1 yr. T4 doses were adapted for a TSH target range of 0.2–0.8 mU/liter. Outcome Measures: The primary end point was percent volume reduction of all nodules measured by ultrasound, and the main secondary end point was a change in goiter volume. Results: Nodule volume reductions were −17.3% [95% confidence interval (CI) −24.8/−9.0%, P < 0.001] in the T4+I group, −7.3% (95% CI −15.0/+1.2%, P = 0.201) in the T4 group, and −4.0% (95% CI −11.4/+4.2%, P = 0.328) in the I group as compared with placebo. In direct comparison, the T4+I therapy was significantly superior to T4 (P = 0.018) or I (P = 0.003). Thyroid volume reductions were −7.9% (95% CI −11.8/−3.9%, P < 0.001), −5.2% (95% CI −8.7/−1.6%, P = 0.024) and −2.5% (95% CI −6.2/+1.4%, P = 0.207), respectively. The T4+I therapy was significantly superior to I (P = 0.034) but not to T4 (P = 0.190). Conclusion: In a region with a sufficient iodine supply, a 1-yr therapy with a combination of I and T4 with incomplete suppression of thyrotropin reduced thyroid nodule volume further than either component alone or placebo.

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Maghsoudipour, M., N. Bosompra, R. Jen, Y. Li, S. Moore, P. DeYoung, J. Fine et al. "0690 An Evaluation Of Genioglossus Strengthening On Obstructive Sleep Apnea Treatment Outcomes". Sleep 43, Supplement_1 (aprile 2020): A263. http://dx.doi.org/10.1093/sleep/zsaa056.686.

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Abstract Introduction Obstructive sleep apnea (OSA) is characterized by repetitive episodes of pharyngeal collapse. The genioglossus is a major upper airway dilator muscle thought to be important in OSA pathogenesis. Upper airway (UA) muscle training has reported benefits in some OSA patients. Our goal was to assess the effect of upper airway muscle training on OSA outcomes. Methods Sixty five patients with OSA (AHI>10/h) were divided in three subgroups: 1) Treated with auto-CPAP (n=21), 2) Previously failed or refused CPAP therapy (no treatment), (n=24), 3) Currently treated with an oral appliance who still have residual OSA (AHI>10/h), (n=20). All subjects were given a custom-made tongue strengthening device. Within each group we conducted a prospective, randomized, controlled study examining the effect of upper airway muscle training. In each subgroup, subjects were randomized to UA muscle training (volitional protrusion against resistance) or sham group (negligible resistance), with 1:1 ratio over 6 weeks of treatment (twice daily for 20 min/session). In the baseline and the final visit, subjects completed home sleep testing, questionnaires (ESS, PSQI), acoustic pharynogometry, Iowa Oral Performance Instrument (IOPI), and Psychomotor Vigilance Test (PVT). Results Results remain blinded; 33 patients received treatment Y and 32 patients received treatment Z. To date, we have not observed a main effect of treatment group on several measures of OSA severity. Some changes in subjective measures over time were observed but difficult to interpret until unblinding occurs. Conclusion Treatment of OSA using upper airway muscle training exercises requires further study. Whether muscle training is a viable approach for a definable subset of OSA patients remains unclear. Support R01HL085188-05A1 (U.S. NIH Grant/Contract)

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Zheng, Weijia, YangQuan Chen, Xiaohong Wang, Meijin Lin e Jing Guo. "Robust fractional order PID controller synthesis for the first order plus integral system". Measurement and Control, 15 settembre 2022, 002029402210955. http://dx.doi.org/10.1177/00202940221095564.

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The fractional order PID (FOPID) controller has been found to have the potential to provide more flexibility in the design options than the integer order PID (IOPID) controller. However, in the FOPID controller design practice, investigations are still required in selecting the achievable design specifications and controller parameters. In order to obtain a practical tuning method for the FOPID controller, taking the first order plus integral systems as the plants, the complete achievable regions of the design specifications are collected and analyzed. In addition, the selectable integral and derivative orders of the FOPID controller are also collected and modeled. With the prior knowledge obtained, a synthesis method for the FOPID controller is proposed to make the control system achieve the desired flat-phase characteristic. To verify the effectiveness of the proposed method, the synthesis method is applied to design the FOPID controller for the permanent magnet synchronous motor (PMSM) speed servo system. Simulation and experimental results show that system with the FOPID controller can achieve satisfying tracking performance and disturbance rejection performance.

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Ghaleb, Ahmed Faisal, Ahmed Alaa Oglah, Amjad J. Humaidi, Abdulkareem Sh Mahdi Al-Obaidi e Ibraheem Kasim Ibraheem. "Optimum of fractional order fuzzy logic controller with several evolutionary optimization algorithms for inverted pendulum". International Review of Applied Sciences and Engineering, 7 settembre 2022. http://dx.doi.org/10.1556/1848.2021.00375.

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Abstract This paper compared the performance between Integer Order Fuzzy PID (IOFPID) and Fractional Order Fuzzy PID (FOFPID) controllers for inverted pendulum system as a controlling plant. The parameters of each controller were tuned with four evolutionary optimization algorithms (Social Spider Optimization (SSO), Swarm Optimization (PSO), Genetic Algorithm (GA), and Particle Ant Colony Optimization (ACO)). The comparisons were carried out between the two controllers IOFPID and FOFPID, as well as among the four optimization algorithms for the two controllers. The results of comparisons proved that the FOFPID controller with SSO has achieved the best time response characteristics and the least tuning time.

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"A Novel Voltage Regulation Technique using Fractional Order PI Controller for a Three Phase Grid Connected Photovoltaic System". International Journal of Recent Technology and Engineering 8, n. 4 (30 novembre 2019): 8260–67. http://dx.doi.org/10.35940/ijrte.d8937.118419.

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The integration of distributed generations (DG’s) to the grid has led to number of challenges apart from the advantages, one of the challenge associated is the voltage regulation. Photovoltaic (PV) system as a DG is considered as it has a better edge when compared to the other DG’s. The application of PV system to the grid requires extra compensating devices to mitigate the voltage regulation issues. A novel voltage regulation strategy for three phase grid connected PV system using fractional order proportional plus integral (FOPI) controller is proposed in this paper. The modelling&analysis of FOPI controller along with the integer orderproportional plus integral (IOPI) controlleris presented in this paper. FOPI controllers are designed in Matlab using FOMCON toolbox (Fractional order Modeling and Control).The simulation is consequently carried out in the Matlab/Simulink environment for both the controllers with resistive loads, resistive & inductive loadsand resistive, inductive & capacitive loads.The FOPI controller outperforms IOPI controller, results of simulation reflectthat controller using FOPI gives better performancewhen compared with the IOPI controller. The effectiveness ofthe FOPI controller confirms the authentication and the simulation results are deliberated for all the different loads.

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25

"Fractional Order PI Controller for Nonlinear Processes using Binomial Theorem Approximation". International Journal of Recent Technology and Engineering 8, n. 4 (30 novembre 2019): 3389–95. http://dx.doi.org/10.35940/ijrte.c6713.118419.

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In Most of the process industries, Integer order Proportional Integral controller (IOPI) has been designed for different processes due to its simplicity but it will damage the final control element due to the sudden change in controller output. So, this research work proposed to eliminate the ringing phenomena by applying large pure time delay in the controller output by proposing Fractional Order Proportional Integral (FOPI) controller using Binomial theorem approximation for the nonlinear conical and spherical tank level processes. The control of liquid level in the nonlinear tank is arduous in nature due to an imbalance in the area of the transverse section of the tank. The robustness of the IOPI and FOPI controllers has demonstrated in Time Domain Specifications (TDS). The FOPI controller eliminates the peak overshoot in the process variable and ringing effect in controller output to protect the pneumatic positioned control valve.

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26

Demiroğlu, Uğur, Bilal Şenol e Radek Matušů. "An examination of complex fractional order physical phenomena in IOPD controller design". Mathematical Methods in the Applied Sciences, 17 maggio 2023. http://dx.doi.org/10.1002/mma.9362.

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27

Galek, Kristine, Ed M. Bice e Giselle Marquez. "Tongue and Lip Comparisons between Healthy and Nondysphagic Poststroke Individuals". Folia Phoniatrica et Logopaedica, 14 luglio 2021, 1–8. http://dx.doi.org/10.1159/000517170.

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Background: The lips and tongue play a substantial role in efficient clearance of food from the mouth and pharynx into the esophagus. No study has compared oral pressures between healthy individuals and poststoke individuals who report functional swallow abilities. Aim: The current study aimed to investigate the presence of differences in oral pressures between healthy individuals and poststroke individuals who report functional swallowing abilities. Design: This is a controlled matched pair study. Population: Eighteen control participants (CG) and 18 nondysphagic poststroke participants (NDSG) were enrolled into this study. Methods: The Iowa Oral Performance Instrument (IOPI) was used to measure and compare tongue strength, endurance, and functional lingual and labial pressures between sex and age-matched pairs. Results: Six paired, two-tailed t tests revealed that tongue and lip pressures were different between the 2 groups. Maximum anterior tongue pressures and posterior tongue pressures were also different, i.e., t(17) = –2.89 (p = 0.010) and t(17) = –2.85 (p = 0.011), with the CG presenting higher pressures. Right lip pressures were significantly lower in the NDSG compared to the CG, i.e., t(17) = 2.45 (p = 0.0001). Left lip pressures were significantly lower in the NDSG compared to the CG, i.e., t(17) = –5.43 (p = 0.0001). Tongue endurance, i.e., t(17) = 0.092 (p = 0.928) and saliva swallow pressures, i.e., t(17) = –0.490 (p = 0.63) were not different. Conclusion: Although poststroke participants reported functional swallowing abilities, there were differences in tongue and lip pressures but not in endurance or saliva swallow pressures. Clinical Rehabilitation Impact: Poststroke individuals without complaints of dysphagia who are not assessed may experience subclinical dysphagia that could negatively impact their nutrition and quality of life.

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