Journal articles: 'RL filter'

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Sariyar, M., and A. Borg. "Deterministic Linkage as a Preceding Filter for Other Record Linkage Methods." International Journal of Information Technology & Decision Making 14, no. 03 (May 2015): 521–33. http://dx.doi.org/10.1142/s0219622015500108.

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Deterministic record linkage (RL) is frequently regarded as a rival to more sophisticated strategies like probabilistic RL. We investigate the effect of combining deterministic linkage with other linkage techniques. For this task, we use a simple deterministic linkage strategy as a preceding filter: a data pair is classified as ‘match' if all values of attributes considered agree exactly, otherwise as ‘nonmatch'. This strategy is separately combined with two probabilistic RL methods based on the Fellegi–Sunter model and with two classification tree methods (CART and Bagging). An empirical comparison was conducted on two real data sets. We used four different partitions into training data and test data to increase the validity of the results. In almost all cases, application of deterministic linkage as a preceding filter leads to better results compared to the omission of such a pre-filter, and overall classification trees exhibited best results. On all data sets, probabilistic RL only profited from deterministic linkage when the underlying probabilities were estimated before applying deterministic linkage. When using a pre-filter for subtracting definite cases, the underlying population of data pairs changes. It is crucial to take this into account for model-based probabilistic RL.

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Bolster, Lauren, Mark Bosch, Brian Brownbridge, and Anurag Saxena. "RAP Trial: Ringer's Lactate and Packed Red Blood Cell Transfusion, An in Vitro Study and Chart Review." Blood 114, no. 22 (November 20, 2009): 2105. http://dx.doi.org/10.1182/blood.v114.22.2105.2105.

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Abstract Abstract 2105 Poster Board II-82 Background: The Canadian Blood Services and the American Association of Blood Banks state that intravenous solution administered with packed red blood cells (pRBC) must be isotonic and must not contain calcium or glucose. This recommendation is based on in vitro investigations demonstrating that calcium containing solutions can initiate in vitro coagulation in citrated blood (Ryden 1975, Dickson 1980, Lorenzo 1998). Recently this recommendation has been challenged by in vitro studies that combined AS-3 pRBC with Ringer's Lactate (RL) (Albert 2009). Currently there are anaesthetists that use RL with pRBC for intra-operative transfusions. The purpose of this study was to evaluate whether RL, as compared with normal saline (NS), can safely be used in transfusion therapy. Methods: Eleven units of AS-3 pRBC were obtained for this study. In part A, multiple dilutions of blood with RL or NS were assessed for clot, both visually using a 20 micron filter and molecularly using F1+2 ELISA. In part B, blood was run through a standard gravity filter with NS or RL, to simulate both ward and intra-operative transfusion practice. The blood was then assessed for clot at times 30, 60, 120, and 240 minutes. In part C, patients who received intra-operative transfusions of pRBC with RL were identified. These charts were reviewed for evidence of transfusion reactions including: TRALI, arterial or venous thrombosis, coagulopathy and mortality. Results: In part A, none of the filters had evidence of visible clot, nor evidence of thrombin generation at supraphysiologic levels, >300 pmol/L (Ota 2008, Pelzer 1991). In part B, there was no visible evidence of clot at the preselected time points. Over four hours the NS + blood group F1+2 levels ranged from 12- 267 pmol/L, and the RL + blood F1+2 levels ranged from 14-218 pmol/L. In the transfusion set primed with blood and then RL added, a simulation of common operating room transfusion practice, the F1+2 ELISA levels ranged from 13-435 pmol/L. There were no statistically significant difference in the ELISA F1+2 between the NS and RL groups (NS + blood vs. RL + blood p= 0.547, NS + blood vs. blood +RL p= 0.663). Nine patients totaling 36 units of pRBC transfused with RL were reviewed. The transfusion times ranging from 15-95 minutes, with an average transfusion time of 30 minutes per unit of pRBC. There was no evidence of transfusion related adverse events identified. Discussion: In addition to our results confirming recent studies that demonstrate in vitro compatibility of pRBC with RL, our study is the first comprehensive study involving visual clot, molecular clot and intra-operative transfusion of pRBC with RL. We have utilized a 20 micron filter, whereas previous studies utilized 40 micron filters. Further, in contrast to other studies we are the first to investigate the effects of both the concentration of RL with blood and the transfusion duration; no other study has looked at four hour transfusions with RL. Conclusion: Our study adds credibility to the hypothesis that RL is safe for clinical transfusion, including intra-operative and ward transfusion practice. Although new evidence now challenges international transfusion guidelines, a larger study should be conducted before transfusion with RL is adopted into widespread clinical practice. Disclosures: No relevant conflicts of interest to declare.

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Spindler, Gerald. "Upload-Filter: Umsetzungsoptionen zu Art. 17 DSM-RL." Computer und Recht 36, no. 1 (January 1, 2020): 50–59. http://dx.doi.org/10.9785/cr-2020-360112.

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Di Gioia, Michele, Luigi Lombardi, Cristoforo Marzocca, Gianvito Matarrese, Giansergio Menduni, Pietro Patimisco, and Vincenzo Spagnolo. "Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications." Micromachines 14, no. 3 (March 8, 2023): 619. http://dx.doi.org/10.3390/mi14030619.

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Quartz tuning forks (QTFs) are employed as sensitive elements for gas sensing applications implementing quartz-enhanced photoacoustic spectroscopy. Therefore, proper design of the QTF read-out electronics is required to optimize the signal-to-noise ratio (SNR), and in turn, the minimum detection limit of the gas concentration. In this work, we present a theoretical study of the SNR trend in a voltage-mode read-out of QTFs, mainly focusing on the effects of (i) the noise contributions of both the QTF-equivalent resistor and the input bias resistor RL of the preamplifier, (ii) the operating frequency, and (iii) the bandwidth (BW) of the lock-in amplifier low-pass filter. A MATLAB model for the main noise contributions was retrieved and then validated by means of SPICE simulations. When the bandwidth of the lock-in filter is sufficiently narrow (BW = 0.5 Hz), the SNR values do not strongly depend on both the operating frequency and RL values. On the other hand, when a wider low-pass filter bandwidth is employed (BW = 5 Hz), a sharp SNR peak close to the QTF parallel-resonant frequency is found for large values of RL (RL > 2 MΩ), whereas for small values of RL (RL < 2 MΩ), the SNR exhibits a peak around the QTF series-resonant frequency.

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Lu, Di, N. Scott Barker, and Xiao-Hong Tang. "Miniaturized dual-band filter with return loss bandwidth and transmission zero control." International Journal of Microwave and Wireless Technologies 9, no. 7 (February 10, 2017): 1459–65. http://dx.doi.org/10.1017/s1759078717000071.

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In this paper, a compact dual-band bandpass filter (DB-BPF) using new dual-mode resonator-loaded resonators (DM-RLRs) is presented and investigated to simultaneously achieve controllable return loss (RL), bandwidth (BW) and transmission zeros (TZs), and the simple strategy for this type of filter design is proposed. The DB-BPF consists of two high-flexibility DM-RLRs with separated electric and magnetic coupling (SEMC). Specifically, the proposed DM-RLR provides the DB-BPF with center frequency control as well as RL control, and SEMC is utilized for the BW and TZ control. To facilitate the design, a simple optimization-based design strategy is proposed and employed, resulting in an example layout. Finally, the example filter, with center frequencies of 1.57 GHz (channel 1 for GPS) and 3.5 GHz (channel 2 for WiMAX), is fabricated and measured. The measurement insertion loss and RL are 0.9/0.9 and 17/20 dB. The fabricated DB-BPF also exhibits a compact size of 0.12λg × 0.08λg at 1.57 GHz.

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Saleem, Mohamed Muftah. "New Method to Harmonic Isolation Based on High Selectivity Filter to Control of Shunt Active Filter with Experimental Validation Using DSPACE System." Applied Mechanics and Materials 666 (October 2014): 53–58. http://dx.doi.org/10.4028/www.scientific.net/amm.666.53.

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This paper presents a new control method of a parallel active power filters based on improved harmonic isolation with hardware implementation. The harmonic isolator is based on High Selectivity Filters (it can be tuned at any frequency) and the current control technique consists in a modulated hysteresis current controller. This active filter is intended for harmonic compensation of a diode rectifier feeding a RL load. The study of the active filter control is divided in two parts. The first part deals with the harmonic isolator which generates the harmonic reference currents and is implemented into a DSPACE DS1104 prototyping card. The second part focuses on the generation of the switching pattern of the IGBTs of the inverter by the modulated hysteresis current controller, implemented into an analogue card. The use of High Selectivity Filters instead of classical extraction filters allows extracting directly the voltage and current fundamental components in the α-β axis at high performances. The effectiveness of the new proposed method is verified by computer simulation and by experimental study.

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Lin, Xingbin, Deyu Yuan, and Xifei Li. "Reinforcement Learning with Dual Safety Policies for Energy Savings in Building Energy Systems." Buildings 13, no. 3 (February 21, 2023): 580. http://dx.doi.org/10.3390/buildings13030580.

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Reinforcement learning (RL) is being gradually applied in the control of heating, ventilation and air-conditioning (HVAC) systems to learn the optimal control sequences for energy savings. However, due to the “trial and error” issue, the output sequences of RL may cause potential operational safety issues when RL is applied in real systems. To solve those problems, an RL algorithm with dual safety policies for energy savings in HVAC systems is proposed. In the proposed dual safety policies, the implicit safety policy is a part of the RL model, which integrates safety into the optimization target of RL, by adding penalties in reward for actions that exceed the safety constraints. In explicit safety policy, an online safety classifier is built to filter the actions outputted by RL; thus, only those actions that are classified as safe and have the highest benefits will be finally selected. In this way, the safety of controlled HVAC systems running with proposed RL algorithms can be effectively satisfied while reducing the energy consumptions. To verify the proposed algorithm, we implemented the control algorithm in a real existing commercial building. After a certain period of self-studying, the energy consumption of HVAC had been reduced by more than 15.02% compared to the proportional–integral–derivative (PID) control. Meanwhile, compared to the independent application of the RL algorithm without safety policy, the proportion of indoor temperature not meeting the demand is reduced by 25.06%.

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Oh, Tae-Ho, Ji-Seok Han, Young-Seok Kim, Dae-Young Yang, Sang-Hoon Lee, and Dong-Il “Dan” Cho. "Deep RL Based Notch Filter Design Method for Complex Industrial Servo Systems." International Journal of Control, Automation and Systems 18, no. 12 (October 21, 2020): 2983–92. http://dx.doi.org/10.1007/s12555-020-0153-y.

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Fernand Koffi, K., Agoua Raoule, Diety Landry, Georges Loum, and Olivier Asseu. "NEW METHOD OF SIZING A FILTER (RL-C) FOR AN INVERTER WITH SPWM CONTROL IN MEDIUM VOLTAGE ALTERNATING." International Journal of Advanced Research 9, no. 04 (April 30, 2021): 34–43. http://dx.doi.org/10.21474/ijar01/12654.

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The need to use SPWM controlled voltage inverters in MV, led us to examine how to filter alternative signals with filters (L-C) and (RL-C). This allowed us to decide on the use of certain formulas for calculating the elements of these filters. Likewise, we have proposed a method of calculating the resistance R by mathematical iterations without using the quality factor Q, in order to obtain a low error rate between the RMS values and the fundamental effective values and THDs respecting the standard 519 IEEE - 2014. The results of these studies obtained using the MATLAB-SIMULINK software are presented in the penultimate session of this article. Nomenclature SPWM Sinusoidal Pulse-Width-Modulation THD Total Harmonic distortion SN Apparent power of the alternating load MV Medium voltage alternating voltage (1 kV --- 50 kV) Uph phase-to-phase voltage at the ac load RMS Root Mean Squared R L C Resistance Inductance Capacitor MVDC Medium voltage direct current VSI Voltage Source Inverter

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Gao, Xile, Haiyong Luo, Bokun Ning, Fang Zhao, Linfeng Bao, Yilin Gong, Yimin Xiao, and Jinguang Jiang. "RL-AKF: An Adaptive Kalman Filter Navigation Algorithm Based on Reinforcement Learning for Ground Vehicles." Remote Sensing 12, no. 11 (May 27, 2020): 1704. http://dx.doi.org/10.3390/rs12111704.

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Kalman filter is a commonly used method in the Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) integrated navigation system, in which the process noise covariance matrix has a significant influence on the positioning accuracy and sometimes even causes the filter to diverge when using the process noise covariance matrix with large errors. Though many studies have been done on process noise covariance estimation, the ability of the existing methods to adapt to dynamic and complex environments is still weak. To obtain accurate and robust localization results under various complex and dynamic environments, we propose an adaptive Kalman filter navigation algorithm (which is simply called RL-AKF), which can adaptively estimate the process noise covariance matrix using a reinforcement learning approach. By taking the integrated navigation system as the environment, and the opposite of the current positioning error as the reward, the adaptive Kalman filter navigation algorithm uses the deep deterministic policy gradient to obtain the most optimal process noise covariance matrix estimation from the continuous action space. Extensive experimental results show that our proposed algorithm can accurately estimate the process noise covariance matrix, which is robust under different data collection times, different GNSS outage time periods, and using different integration navigation fusion schemes. The RL-AKF achieves an average positioning error of 0.6517 m within 10 s GNSS outage for GNSS/INS integrated navigation system and 14.9426 m and 15.3380 m within 300 s GNSS outage for the GNSS/INS/Odometer (ODO) and the GNSS/INS/Non-Holonomic Constraint (NHC) integrated navigation systems, respectively.

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11

Wolf, Marina. "Overinterpretation or appropriation?" Institutionalization of science and the scientific community 1, no. 2020.1.1 (October 20, 2020): 58–68. http://dx.doi.org/10.47850/rl.2020.1.1.58-68.

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The article discusses various approaches to interpretation, which understand it as a universal method of the humanities. Particular attention we paid to the interpretations in U. Eco and E. Batti, who, although do not agree with each other, however, are opposed both to the philosophic or analytic understanding of interpretation, which we call the appropriationist approach. The way of interpreting the past inherent in appropriationism often threatens with overinterpretation, for which it is criticized by adepts of contextualism. We analyze the interpretation through the prism of three skeptical arguments we offered, “conceptual relativism”, “Gorgians’ minds”, “the part and the whole”. Skeptical arguments are often used in philosophy as an additional filter for testing the consistency of the concepts, and it is clearly seen that the contextualist concept of interpretation does not pass this filter. The thesis that appropriation is indeed a overinterpretation can be accepted under reserve that for a strictly philosophical way of reasoning and from within appropriationism, another version of interpretation is inconsistent.

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12

Yazdanian, Mehrdad, and Ali Mehrizi-Sani. "Internal Model-Based Current Control of the RL Filter-Based Voltage-Sourced Converter." IEEE Transactions on Energy Conversion 29, no. 4 (December 2014): 873–81. http://dx.doi.org/10.1109/tec.2014.2353035.

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13

Akintade, S. A., Y. Jibril, and A. S. Abubakar. "Development of Shunt Active Power Filter for Harmonic Reduction using Synchronous Reference Frame with Space Vector Pulse Width Modulation." Nigerian Journal of Technological Development 17, no. 2 (July 22, 2020): 104–12. http://dx.doi.org/10.4314/njtd.v17i2.5.

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The work aims at development of Shunt Active Power Filter (SAPF) for harmonic reduction. The current harmonics are being caused by nonlinear characteristic of power electronics based equipments which increase power losses and in turn reduce power quality. Synchronous Reference Frame (SRF) was used as a control strategy and for reference harmonic current generation and Space Vector Pulse Width Modulation (SVPWM) was adopted as switching signal generation. With RL load under balanced input voltage condition, the developed SAPF-SVPWM achieved a reduction of THD of 0.91% as compared to 25.60 before compensation. In addition, the developed SAPF- SVPWM model was compared with SAPF without compensation using RL load under unbalanced voltage and the result shows that the developed SVPWM achieved reduction in THD of 1.74 % as compared to 26.68% after and before compensation. The developed SVPWM model was also compared with SPWM balanced and unbalanced voltage condition. The results show that SVPWM performed better than SPWM. All the results obtained are within IEEE 519 harmonics standard (i.e. THD less than 5%) with nonlinear load under balanced and unbalanced voltage. Keywords: Shunt active filter, input voltage, harmonics, space vector pulse width modulation, nonlinear load.

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14

Jin, Zengwang, Menglu Ma, Shuting Zhang, Yanyan Hu, Yanning Zhang, and Changyin Sun. "Secure State Estimation of Cyber-Physical System under Cyber Attacks: Q-Learning vs. SARSA." Electronics 11, no. 19 (October 1, 2022): 3161. http://dx.doi.org/10.3390/electronics11193161.

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This paper proposes a reinforcement learning (RL) algorithm for the security problem of state estimation of cyber-physical system (CPS) under denial-of-service (DoS) attacks. The security of CPS will inevitably decline when faced with malicious cyber attacks. In order to analyze the impact of cyber attacks on CPS performance, a Kalman filter, as an adaptive state estimation technology, is combined with an RL method to evaluate the issue of system security, where estimation performance is adopted as an evaluation criterion. Then, the transition of estimation error covariance under a DoS attack is described as a Markov decision process, and the RL algorithm could be applied to resolve the optimal countermeasures. Meanwhile, the interactive combat between defender and attacker could be regarded as a two-player zero-sum game, where the Nash equilibrium policy exists but needs to be solved. Considering the energy constraints, the action selection of both sides will be restricted by setting certain cost functions. The proposed RL approach is designed from three different perspectives, including the defender, the attacker and the interactive game of two opposite sides. In addition, the framework of Q-learning and state–action–reward–state–action (SARSA) methods are investigated separately in this paper to analyze the influence of different RL algorithms. The results show that both algorithms obtain the corresponding optimal policy and the Nash equilibrium policy of the zero-sum interactive game. Through comparative analysis of two algorithms, it is verified that the differences between Q-Learning and SARSA could be applied effectively into the secure state estimation in CPS.

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Nicola, Marcel, Claudiu-Ionel Nicola, Dumitru Sacerdoțianu, and Adrian Vintilă. "Comparative Performance of UPQC Control System Based on PI-GWO, Fractional Order Controllers, and Reinforcement Learning Agent." Electronics 12, no. 3 (January 17, 2023): 494. http://dx.doi.org/10.3390/electronics12030494.

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In this paper, based on a benchmark on the performance of a Unified Power Quality Conditioner (UPQC), the improvement of this performance is presented comparatively by using Proportional Integrator (PI)-type controllers optimized by a Grey Wolf Optimization (GWO) computational intelligence method, fractional order (FO)-type controllers based on differential and integral fractional calculus, and a PI-type controller in tandem with a Reinforcement Learning—Twin-Delayed Deep Deterministic Policy Gradient (RL-TD3) agent. The main components of the UPQC are a series active filter and an Active Parallel Filter (APF) coupled to a common DC intermediate circuit. The active series filter provides the voltage reference for the APF, which in turn corrects both the harmonic content introduced by the load and the VDC voltage in the DC intermediate circuit. The UPQC performance is improved by using the types of controllers listed above in the APF structure. The main performance indicators of the UPQC-APF control system for the controllers listed above are: stationary error, voltage ripple, and fractal dimension (DF) of the VDC voltage in the DC intermediate circuit. Results are also presented on the improvement of both current and voltage Total harmonic distortion (THD) in the case of, respectively, a linear and nonlinear load highly polluting in terms of harmonic content. Numerical simulations performed in a MATLAB/Simulink environment demonstrate superior performance of UPQC-APF control system when using PI with RL-TD3 agent and FO-type controller compared to classical PI controllers.

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Ruffo, Riccardo, Paolo Guglielmi, and Eric Armando. "Inverter Side RL Filter Precise Design for Motor Overvoltage Mitigation in SiC-Based Drives." IEEE Transactions on Industrial Electronics 67, no. 2 (February 2020): 863–73. http://dx.doi.org/10.1109/tie.2019.2898623.

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17

Liu, Qiu, Shen, Jiao, Ye, Xie, Wang, Xiao, and Zhao. "Additive Manufacturing of Monolithic Microwave Dielectric Ceramic Filters via Digital Light Processing." Electronics 8, no. 10 (September 20, 2019): 1067. http://dx.doi.org/10.3390/electronics8101067.

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Microwave dielectric ceramics are employed in filters as electromagnetic wave propagation media. Based on additive manufacturing (AM) techniques, microwave dielectric ceramic filters with complex and precise structures can be fabricated to satisfy filtering requirements. Digital light processing (DLP) is a promising AM technique that is capable of producing filters with high accuracy and efficiency. In this paper, monolithic filters made from Al2O3 and TiO2, with a molar ratio of9:1 (0.9 Al2O3-0.1 TiO2), were fabricated by DLP. The difference in the dielectric properties between the as-sintered and post-annealed samples at different temperatures was studied. The experimental results showed that when sintered at 1550 °C for 2 h and post annealed at 1000 °C for 5 h, 0.9 Al2O3-0.1 TiO2 exhibited excellent dielectric properties: εr = 12.4, Q × f = 111,000 GHz, τf = + 1.2 ppm/°C. After comparing the measured results with the simulated ones in the passband from 6.5 to 9 GHz, it was concluded that the insertion loss (IL) and return loss (RL) of the filter meet the design requirements.

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Kumar, Ashwani, A. K. Verma, and Nainu P. Chaudhari. "DESIGN OF BESSEL LOW PASS FILTER USING DGS WITH IMPROVED CHARACTERISTICS FOR RF/MICROWAVE APPLICATIONS." Journal of Circuits, Systems and Computers 23, no. 09 (August 25, 2014): 1450122. http://dx.doi.org/10.1142/s0218126614501229.

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We report a synthesis process to design the defected ground structure (DGS)-based Bessel lowpass filter (LPF). For 5-pole LPF at fc = 2.5 GHz, its selectivity is 10.6 dB/GHz and for the DGS-based Butterworth LPF it is 12.6 dB/GHz. For the lumped elements Bessel LPF, it is only 4.84 dB/GHz. Its 20 dB rejection bandwidth is 13.1 GHz and impedance matching BW is 76%, as against 88.8% for Butterworth LPF. At fc = 7.5 GHz, the 5-pole DGS Bessel LPF has selectivity 7 dB/GHz, 20 dB rejection BW is 13 GHz and 10 dB return loss (RL) BW in passband is 4.86 GHz (64.8%) with less than 7.9 pS group delay (GD) variation. In case of a bulky mixed microstrip-waveguide (MMW) 5-pole Bessel LPF at 7.5 GHz [W. Menzel and F. Boigelsack, 29th European Microwave Conference, Munich (1999), pp. 191–194.], reported results are: sharpness of cut-off 1.48 dB/GHz, 10 dB RL BW and GD variation are 48% and 4 pS, respectively. The improved performance the DGS-based Bessel LPF can find applications in high speed data communication, front-end of a wideband communication system and in a power amplifier, by improving the selectivity, suppression of harmonics and linear distortion.

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Mokrani, Bilal, Renaud Bastaits, Mihaita Horodinca, Iulian Romanescu, Ioanica Burda, Régis Viguié, and André Preumont. "Parallel Piezoelectric Shunt Damping of Rotationally Periodic Structures." Advances in Materials Science and Engineering 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/162782.

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This paper considers the RL shunt damping of rotationally periodic structures with an array of regularly spaced piezoelectric patches. The technique is targeted to the damping of a specific mode withnnodal diameters. For this particular case, one can take advantage of the shape of the targeted mode to organize the piezoelectric patches as a modal filter (in parallel loops) which reduces the demand on the inductors of the tuned inductive shunt. In the case of a perfectly rotationally periodic structure, it is possible to organize 4npiezoelectric transducers (PZT patches) in two parallel loops of 2npatches each. In this way, the demand on the inductors is reduced by4n2as compared to independent loops, which may allow a fully passive integration of the RL shunt in a turbomachinery application. The method is first illustrated experimentally on a circular plate; it is then applied to a prototype of an industrial bladed drum. The influence of blade mistuning is investigated.

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Kumar, A. Siva, and N. B. Muthu Selvan. "Reduction of Source Current Harmonics in R and Rl Load with Active Filter at Source End." Asian Journal of Research in Social Sciences and Humanities 6, no. 10 (2016): 298. http://dx.doi.org/10.5958/2249-7315.2016.01015.7.

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21

Denisenko, K. I., V. O. Lesyk, and T. V. Mysak. "INFLUENCE OF THE FILTER IN THE CONTROL CHANNEL CONTOURS OF THE STORAGE CAPACITOR VOLTAGE STABILIZATION ON THE DYNAMICS IN THREE-PHASE SHUNT ACTIVE POWER FILTER." Praci Institutu elektrodinamiki Nacionalanoi akademii nauk Ukraini 2021, no. 58 (May 19, 2021): 55–65. http://dx.doi.org/10.15407/publishing2021.58.055.

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The object of research is a three-phase shunt active power filter, which consists of a semiconductor voltage inverter on fully controllable switches, capacitive storage, and an RL-link. The carried-out decomposition of the research object according to the rate of motion of the dynamic system makes it possible to divide this dynamic system into two subsystems, interconnected by control. The role and influence of the communication subsystem between the voltage stabilization circuit on the storage capacitor of the three-phase shunt active power filter and the circuits for the formation of the compensation current, which is injected by this filter into the distributed power supply network, is considered. The presence of a non-linear load in this network is a source of distortion of the parameters of electrical energy. The formation of the compensation current by the forced introduction of the first order sliding modes along some sliding surfaces was carried out. The two-dimensional sliding surface is a linear combination of the components of the two-dimensional error vectors of the compensation current and the first derivative of the error of this current. The introduced communication subsystem makes it possible to reduce the influence of the disturbance in the form of harmonic components of the rectified voltage on the parameters of the compensating current. The influence of the dynamic characteristics of a communication subsystem with filtering properties on the performance indicators of a parallel active filter and the current distortion factor in the power supply network to which this filter is connected was analyzed. To confirm the theoretical assumptions, a simulation model was built and the results of digital modeling were analyzed. Comparison of different types of filters as a communication subsystem according to the criteria of the duration of the transient process and the harmonic distortion in the current that consumed from the network was carried out. References 26, figures 4, tables 3.

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Volkmann, Caroline. "Art. 17 Urh-RL und die Upload-Filter: verschärfte Störerhaftung oder das Ende der Freiheit im Internet?" Computer und Recht 35, no. 6 (June 1, 2019): 376–84. http://dx.doi.org/10.9785/cr-2019-350612.

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Verma, Atul Kumar, Indu Saini, and Barjinder Singh Saini. "The baseline wandering noise removal from ECG signal using forward–backward Riemann Liouville fractional integral-based empirical wavelet transform approach." International Journal of Wavelets, Multiresolution and Information Processing 16, no. 06 (October 10, 2018): 1850049. http://dx.doi.org/10.1142/s0219691318500492.

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The electrocardiogram (ECG) non-invasively monitors the electrical activities of the heart to diagnose the heart-related diseases. The baseline wandering noise affects the diagnosis of the heart diseases. In this paper, the baseline wandering noise removal is done using forward–backward Riemann Liouville (RL) fractional integral-based empirical wavelet transform (EWT) approach. In the designed methodology, firstly, the noisy ECG signal is decomposed into various modes from low to high frequencies. Then, the first mode is processed to remove the baseline wandering noise. The processed EWT mode is filtered by the fractional RL filter used in the forward direction and then in the backward direction for removing the baseline wandering noise from the ECG signal. After that, the processed and the unprocessed modes are used to reconstruct the denoised ECG signal. The clean ECG signal record is taken from MIT-BIH ECG-ID database, and the baseline wandering noise record is taken from the MIT-BIH noise stress test database. The performance of the proposed approach is validated in terms of the output signal-to-noise ratio (SNR[Formula: see text]). The comparative study has also been done between the proposed denoising approach and the existing state-of-the-art denoising algorithms. The experimental result proves the supremacy of our proposed denoising approach.

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Eddine, Ameur Taki, Aissa Ameur, and Benalia Atallah. "RNA Identification Technique and RST Control of a Hybrid Indirect Matrix Converter with a Flying Capacitor Three Level Inverter in Power Active Filtering Application." Journal Européen des Systèmes Automatisés 54, no. 5 (October 31, 2021): 743–49. http://dx.doi.org/10.18280/jesa.540509.

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The present paper deals with RST controller using implementation of neural architectures to control power electronics systems dedicated to power quality improvement in a distribution grid. We present a technique for designing a robust RST controller, The computation of the controller is used to enhance the control a Hybrid Indirect Matrix Converter with a flying capacitor three level inverter (HIMC) coupled to the power grid (PG) by an RL filter, the synthesizing of this RST controller is formulated through open and close loop. Artificial neuronal network (ANN) identification technique is used to define/extract this disturbance. Simulation results by MATLAB, Simscap/sim power system code shows the effectiveness of the proposed method.

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Mysak, T. V. "STABILITY ANALYSIS OF THE VOLTAGE STABILIZATION SYSTEM ON THE STORAGE CAPACITOR OF THE THREE-PHASE SHUNT ACTIVE FILTER." Tekhnichna Elektrodynamika 2023, no. 1 (January 9, 2023): 12–17. http://dx.doi.org/10.15407/techned2023.01.012.

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The object of the study is a three-phase shunt active power filter, which consists of a two-level voltage inverter, a capacitive storage device and a damping RL-link. Decomposition of the object of study according to the rate of motion of a dynamic system makes it possible to divide this system into two subsystems, interconnected by control. The influence of the dynamic characteristics of the low-pass filter, which acts as a subsystem of communication between the voltage stabilization circuit on the capacitor of the three-phase shunt active power filter and the circuits of compensating current, on the stability of the system is considered. The formation of the compensation current is carried out by forcing the introduction of sliding modes of the first order. The mathematical model of the voltage stabilization subsystem on the capacitor using the vector of the equivalent control under the assumption of the existence of a sliding mode in the formation of the compensation current was built. The analysis of the stability of the voltage stabilization system using a low-pass filter of the second order on the first approximation was performed. To do this, the characteristic equation of a closed system for which an interval characteristic polynomial was constructed, the Kharitonov theorem, and the Rauss-Hurwitz method for a family of these polynomials was used. To confirm the theoretical assumptions, a simulation model was built and the results of digital modeling were analyzed. References 9, figure 1.

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Yang, Jui-An, and Chung-Hsien Kuo. "Integrating Vehicle Positioning and Path Tracking Practices for an Autonomous Vehicle Prototype in Campus Environment." Electronics 10, no. 21 (November 5, 2021): 2703. http://dx.doi.org/10.3390/electronics10212703.

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This paper presents the implementation of an autonomous electric vehicle (EV) project in the National Taiwan University of Science and Technology (NTUST) campus in Taiwan. The aim of this work was to integrate two important practices of realizing an autonomous vehicle in a campus environment, including vehicle positioning and path tracking. Such a project is helpful to the students to learn and practice key technologies of autonomous vehicles conveniently. Therefore, a laboratory-made EV was equipped with real-time kinematic GPS (RTK-GPS) to provide centimeter position accuracy. Furthermore, the model predictive control (MPC) was proposed to perform the path tracking capability. Nevertheless, the RTK-GPS exhibited some robust positioning concerns in practical application, such as a low update rate, signal obstruction, signal drift, and network instability. To solve this problem, a multisensory fusion approach using an unscented Kalman filter (UKF) was utilized to improve the vehicle positioning performance by further considering an inertial measurement unit (IMU) and wheel odometry. On the other hand, the model predictive control (MPC) is usually used to control autonomous EVs. However, the determination of MPC parameters is a challenging task. Hence, reinforcement learning (RL) was utilized to generalize the pre-trained datum value for the determination of MPC parameters in practice. To evaluate the performance of the RL-based MPC, software simulations using MATLAB and a laboratory-made, full-scale electric vehicle were arranged for experiments and validation. In a 199.27 m campus loop path, the estimated travel distance error was 0.82% in terms of UKF. The MPC parameters generated by RL also achieved a better tracking performance with 0.227 m RMSE in path tracking experiments, and they also achieved a better tracking performance when compared to that of human-tuned MPC parameters.

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Wang, Seunghun, Jinseok Park, and Songcheol Hong. "A K-Band Variable-Gain Phase Shifter Based on Gilbert-Cell Vector Synthesizer With RC–RL Poly-Phase Filter." IEEE Microwave and Wireless Components Letters 31, no. 4 (April 2021): 393–96. http://dx.doi.org/10.1109/lmwc.2021.3056881.

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Yuen, Ken Kuen-Faat, and Henry Shu-Hung Chung. "A Low-Loss “RL-Plus-C” Filter for Overvoltage Suppression in Inverter-Fed Drive System With Long Motor Cable." IEEE Transactions on Power Electronics 30, no. 4 (April 2015): 2167–81. http://dx.doi.org/10.1109/tpel.2014.2325824.

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Elhaj, Nabil, Moulay Brahim Sedra, Tarik Jarou, and Hind Djeghloud. "An Improved Double Fuzzy PI Controller For Shunt Active Power Filter DC Bus Regulation." International Journal of Power Electronics and Drive Systems (IJPEDS) 6, no. 2 (June 1, 2015): 337. http://dx.doi.org/10.11591/ijpeds.v6.i2.pp337-347.

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This paper targets to demonstrate the importance of the choice of the algorithm references detection to be applied with a double fuzzy PI corrector (DFPI) for the control and the regulation of a shunt active power filter (SAPF) DC bus voltage. In a previous work, the synchronous reference frame (SRF) algorithm was applied and gave satisfactory results. In the present paper, the SRF is substituted by the positive sequence of the fundamental of the source voltage algorithm (PSF) which offered better results regarding the power quality of the considered main utility feeding a variable DC RL load throughout a diode bridge. The results were carried out using computer simulation perfomed under MATLAB/Simulink environment. To make the obtained results more convenient, a comparison between the couples (SRF, PI), (PSF, PI), (SRF, DFPI), (PSF, DFPI) is added to prove the effectiveness of the couple (PSF, DFPI) in satisfying the compromise between a good regulation of the SAPF DC bus voltage and a good quality of filtering resulting in an improved quality of power.

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Essakhi, Hassan, Sadik Farhat, Yahya Dbaghi, and Diyae Daou. "Indirect power control of grid-connected photovoltaic system using fuzzy control with a three-level inverter." Indonesian Journal of Electrical Engineering and Computer Science 28, no. 1 (October 1, 2022): 76. http://dx.doi.org/10.11591/ijeecs.v28.i1.pp76-87.

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This paper proposes an enhanced study of a photovoltaic generator (PVG) connected to the grid. A fuzzy maximum power point tracking (MPPT) is used to extract maximum power. The control strategy adopted gives the possibility to control separately the active and reactive power. the voltage control at the input of the three levels inverter allows fixing the reference currents in the DQ frame to control indirectly the power injected into the grid. The use of a three-level neutral point clamped voltage source inverter (3L-NPC-VSI) with space vector pulse width modulation (SVPWM) control and the RL filter allows to have a quality current and voltage wave with a minimum total harmonic distortion (THD). The simulation results on MATLAB/Simulink confirm the performance of this proposed strategy in the steady-state with high efficiency.

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Kumaresan, S., and H. Habeebullah Sait. "Embedded System Implementation of Shunt Active Power Filter with Direct Compensation Component Generation Using Linear Operational Amplifiers." Journal of Circuits, Systems and Computers 29, no. 10 (January 10, 2020): 2050166. http://dx.doi.org/10.1142/s0218126620501662.

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In this paper, the principles, the design, the methodology of low cost implementation and the results of implementation of a shunt active power filter (SAPF) in the embedded system environment are presented. The system for which the SAPF is considered has a combination of linear reactive load and a three-phase-fed diode bridge rectifier that drives an RL load. The generation of the compensating signal or the reference signal is based upon the direct calculations implemented using the linear operational amplifiers. Further, the generation of the pulse width modulation (PWM) pulses is much similar to the conventional sinusoidal PWM but implemented in the embedded system platform. In this work, the built-in PWM and ADC sections of the microcontroller PIC 16F877A have been utilized for generating the PWM pulses without the requirement of an explicit carrier signal. The proposed method has been validated in MATLAB SIMULINK environment and also by an experimental prototype.

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Ahmed, Mostafa, Mohamed Abdelrahem, and Ralph Kennel. "Highly Efficient and Robust Grid Connected Photovoltaic System Based Model Predictive Control with Kalman Filtering Capability." Sustainability 12, no. 11 (June 3, 2020): 4542. http://dx.doi.org/10.3390/su12114542.

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Renewable energy sources, especially photovoltaic (PV) ones, are gaining more and more interest due to the predicted lack of conventional sources over the coming years. That shortage is not the only concern, as environmental issues add to this concern also. Thus, this study proposes two-stage PV grid connected system, which is supported with extended Kalman filter (EKF) for parameter estimation. In the first stage, maximum power point tracking (MPPT) for the boost converter is accomplished using new MPPT method in which the switching state of the converter is directly generated after the measurement stage, so it is called direct switching MPPT technique. This technique is compared with the conventional finite control set model predictive control (FCS-MPC) method, where the design of the cost function is based on minimizing the error between the reference and the actual current. The reference current is obtained by employing perturb and observe (P&O) method. In the second stage, the two-level inverter is controlled by means of model predictive control (MPC) with reduced computation burden. Further, to overcome the parameter variations, which is a very common problem in MPC applications, an extended Kalman filter is utilized to eliminate the control algorithm’s dependency on the parameters by providing an efficient estimation. After the inverter, an RL filter is inserted to guarantee the quality of the currents injected into the grid. Finally, the system is validated using Matlab under different operating conditions of atmospheric variation and parameter changes.

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Guo, Huanhuan, Yong Liu, Jidai Chen, Yan Zhu, and Zihan Zhang. "The Effects of Several Metal Nanoparticles on Seed Germination and Seedling Growth: A Meta-Analysis." Coatings 12, no. 2 (January 31, 2022): 183. http://dx.doi.org/10.3390/coatings12020183.

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Using the proper means to improve seed germination is of great significance in agriculture and forestry. Here, a meta-analysis was used to examine whether metal nanoparticle treatments have a specific effect on the seed germination and seedling growth of agricultural species. Using the Web of Science (1950–2021), PubMed (1950–2021), and Scopus (1950–2021) databases, a paper search was conducted using the following items (“nanoparticles” and “seed germination”, “nanomaterials” and “seed germination”) to filter the references in the title, abstract, and keywords of the published articles. The results indicated that nanoparticle (NP) treatments had a significantly positive effect on the final germination percentage (FGP), with a mean difference (MD) (that is, the overall effect) of 1.97 (0.96, 2.98) for the silver (Ag)-NP subgroup, 1.21 (0.34, 2.09) for the other-NP subgroup, 1.40 (0.88, 1.92) for the total based on the NP types, 1.47 (0.85, 2.09) for the “Concentrations: <50 mg/L” subgroup, and 1.40 (0.88, 1.92) for the total based on the NP concentrations. Similarly, root length (RL) was positively and significantly affected by NP treatment, with an MD (95% CI) of 0.92 (0.76, 1.09) for the zinc (Zn)-NP subgroup, 0.79 (0.65, 0.92) for the other-NP subgroup, 0.82 (0.72, 0.93) for the total based on the NP types, 0.90 (0.77, 1.04) for the “Concentrations: ≤50 mg/L” subgroup, 0.80 (0.60, 0.99) for the “Concentrations: >50 mg/L” subgroup, and 0.82 (0.72, 0.93) for the total based on the NP concentrations. However, there was no statistical correlation between the nanoparticle concentrations and shoot length (SL), due to the inclusion of zero in the 95% CI of the overall effect. Therefore, Ag-NPs could increase the FGP more than other-NPs, while Zn-NPs enhanced RL more. Moreover, NPs at lower concentrations could improve the FGP and RL of crop species to a larger extent than NPs at higher concentrations. This meta-analysis can provide a reference for the nanoparticle treatment technology utilization in agricultural and forest seeds.

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Mustafa, K. A. A., N. Botteghi, B. Sirmacek, M. Poel, and S. Stramigioli. "TOWARDS CONTINUOUS CONTROL FOR MOBILE ROBOT NAVIGATION: A REINFORCEMENT LEARNING AND SLAM BASED APPROACH." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W13 (June 5, 2019): 857–63. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w13-857-2019.

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<p><strong>Abstract.</strong> We introduce a new autonomous path planning algorithm for mobile robots for reaching target locations in an unknown environment where the robot relies on its on-board sensors. In particular, we describe the design and evaluation of a deep reinforcement learning motion planner with continuous linear and angular velocities to navigate to a desired target location based on deep deterministic policy gradient (DDPG). Additionally, the algorithm is enhanced by making use of the available knowledge of the environment provided by a grid-based SLAM with Rao-Blackwellized particle filter algorithm in order to shape the reward function in an attempt to improve the convergence rate, escape local optima and reduce the number of collisions with the obstacles. A comparison is made between a reward function shaped based on the map provided by the SLAM algorithm and a reward function when no knowledge of the map is available. Results show that the required learning time has been decreased in terms of number of episodes required to converge, which is 560 episodes compared to 1450 episodes in the standard RL algorithm, after adopting the proposed approach and the number of obstacle collision is reduced as well with a success ratio of 83% compared to 56% in the standard RL algorithm. The results are validated in a simulated experiment on a skid-steering mobile robot.</p>

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Mandic, V., Z. Bijelic, V. Krnjaja, Z. Tomic, A. Simic, D. Ruzic-Muslic, and M. Gogic. "The influence of genotype and osmotic stress on germination and seedling of maize." Biotehnologija u stocarstvu 30, no. 2 (2014): 357–66. http://dx.doi.org/10.2298/bah1402357m.

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The aim of this research was to estimate the influence of different NaCl osmotic solutions (0, -0.3 MPa, -0.6 MPa, -0.9 MPa, -1.2 MPa, -1.5 MPa) on seed germination, and early seedling growth in two maize hybrid different maturity groups (ZP 560 - FAO 500 and ZP 666 - FAO 600). Germination was tested in sterile plastic vessels on filter paper moistened with different NaCl solutions, in the dark at 20 ? 1?C, in laboratory. Results of ANOVA indicated that hybrid ZP 666 had significantly higher root length (RL) (6.37 cm), shoot length (ShL) (2.06 cm), shoot fresh weight (ShFW) (43.86 mg), root dry weight (RDW) (7.56 mg), shoot dry weight (ShDW) (5.97 mg), seedling vigor index (SVI) (706.55) and dry matter stress tolerance index (DMSI) (55.85%) than hybrid ZP 560 (4.18 cm, 1.14 cm, 32.50 mg, 6.54 mg, 4.15 mg, 457.61 and 48.86%, respectively). Contrary, hybrid ZP 560 had significantly higher relative seedling water content (RSWC) (83.83%) and phytotoxicity of shoot (PhSh) (69.77%) than hybrid ZP 666 (81.16% and 62.51%, respectively). Generally, hybrid ZP 666 had better tolerance to salt stress than hybrid ZP 560. Germination energy (GE), germination (G), RL, ShL, root fresh weight (RFW), ShFW, RDW, ShDW, rate germination index (RGI), SVI, RSWC and DMSI were significantly decreased with the increase in osmotic stress induced by NaCl. Contrary, phytotoxicity of root (PhR) and PhSh significantly increased with the increase in osmotic stress.

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Mandic, V., V. Krnjaja, Z. Bijelic, Z. Tomic, A. Simic, D. Ruzic-Muslic, and A. Stanojkovic. "Genetic variability of red clover seedlings in relation to salt stress." Biotehnologija u stocarstvu 30, no. 3 (2014): 529–38. http://dx.doi.org/10.2298/bah1403529m.

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Red clover is highly salt-sensitive plant, especially during germination and early seedling growth stages. The aim of this investigation was to estimate the effects of different saline conditions (0, 50, 100, 150, and 200mM NaCl) on germination and early seedling growth in four red clover varieties (Kolubara, K-32, K-17 and K-39). Germination test was conducted in the laboratory conditions using sterile plastic vessels on filter paper moistened with 10ml of the appropriate salt test solutions. It was observed that the germination energy (GE), germination (G), percentage of dead or infected seeds (DIS), normal seedlings (NS), root length (RL), shoot length (ShL), fresh weight (FW) and dry weight of seedling (DW) and seedling vigor index (SVI) were significantly decreased with increasing concentrations of NaCl in the growing medium. The tested varieties of red clover showed different NaCl tolerance at the seedling stage. Generally, studied red clover varieties are very sensitive to salt, especially K-32 which has the lowest values for GE, G, NS and SVI and highest for DIS. Variety K-17 proved to be a variety that the best tolerates conditions of salt stress because the values for GE, G, NS, RL and SVI were highest. Testing of varieties of red clover in the early seedling growth at different concentrations of NaCl in the growing medium could be helpful in the identification and selection of varieties for cultivation on saline soils.

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Ouchatti, Abderrahmane, Redouane Majdoul, Ahmed Moutabir, Abderrahim Taouni, and Abdelouahed Touati. "Modified T-type topology of three-phase multi-level inverter for photovoltaic systems." International Journal of Electrical and Computer Engineering (IJECE) 12, no. 1 (February 1, 2022): 262. http://dx.doi.org/10.11591/ijece.v12i1.pp262-268.

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In this article, a three-phase multilevel neutral-point-clamped inverter with a modified t-type structure of switches is proposed. A pulse width modulation (PWM) scheme of the proposed inverter is also developed. The proposed topology of the multilevel inverter has the advantage of being simple, on the one hand since it does contain only semiconductors in reduced number (corresponding to the number of required voltage levels), and no other components such as switching or flying capacitors, and on the other hand, the control scheme is much simpler and more suitable for variable frequency and voltage control. The performances of this inverter are analyzed through simulations carried out in the MATLAB/Simulink environment on a three-phase inverter with 9 levels. In all simulations, the proposed topology is connected with R-load or RL-load without any output filter.

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Zhang, Nan, Xiaolong Wang, Chunxi Bao, Bin Wu, Chun-Ping Chen, Zhewang Ma, and Geyu Lu. "A Novel Synthetization Approach for Multi Coupled Line Section Impedance Transformers in Wideband Applications." Applied Sciences 12, no. 2 (January 15, 2022): 875. http://dx.doi.org/10.3390/app12020875.

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In this paper, a novel synthetization approach is proposed for filter-integrated wideband impedance transformers (ITs). The original topology consists of N cascaded coupled line sections (CLSs) with 2N characteristic impedance parameters. By analyzing these characteristic impedances, a Chebyshev response can be derived to consume N + 2 design conditions. To optimize the left N − 2 variable parameters, CLSs were newly substituted by transmission lines (TLs) to consume the remaining variable parameters and simplify the circuit topology. Therefore, there are totally 2N − N − 2 substituting possibilities. To verify the proposed approach, 25 cases are listed under the condition of N = 5, and 7 selected cases are compared and discussed in detail. Finally, a 75–50 Ω IT with 100% fractional bandwidth and 20 dB bandpass return loss (RL) is designed and fabricated. The measured results meet the circuit simulation and the EM simulation accurately.

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Wentzel, Andreas, Maruf Hossain, Dimitri Stoppel, Nils Weimann, Viktor Krozer, and Wolfgang Heinrich. "An efficient W-band InP DHBT digital power amplifier." International Journal of Microwave and Wireless Technologies 9, no. 6 (March 14, 2017): 1241–49. http://dx.doi.org/10.1017/s1759078717000198.

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This paper presents for the first time high-efficiency W-band power amplifiers (PAs), the design of which follows the digital PA (DPA) design concept. Two DPAs with different output networks have been realized: a single-band version (S-DPA) for 95 GHz and a dual-band design (D-DPA) for signal frequencies fSof 68 GHz (first band) and 76 GHz (second band), respectively. The PAs are realized as monolithic microwave-integrated circuits (MMICs) in a 0.8 μm InP DHBT transferred-substrate process. They utilize a double-emitter-finger DHBT unit cell with an emitter area of 2 × 0.8 × 6 μm3each. In contrast to the usual W-band PAs, the proposed single-stage amplifier MMICs do not apply any special reactive matching for the transistor, which leads to very compact chip sizes of 0.27 mm2(S-DPA) and 0.39 mm2(D-DPA). The S-DPA includes one band-pass filter (BPF) at the output with 0.6 dB insertion loss (IL) and 24 dB input return loss (RL) at the signal frequency of 95 GHz. The dual-band BPF shows 0.7 dB IL in both bands with a RL of more than 21 dB each. Applying an overdriven sinusoidal input signal to emulate digital operation the DPAs achieve a maximum output power of 14.4 dBm and power-added efficiency of 31% when using the single-band configuration. Collector efficiencies of more than 80% and the flexible multi-band operation demonstrated prove the great potential of the digital PA concept for future high-speed communications.

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Algburi, Ali Qasim Hussein, and P. V. Ramana Rao. "A simplified PWM technique for PV fed Five-Level Five switch Multilevel Inverter." International Journal of Engineering & Technology 7, no. 4.24 (November 27, 2018): 4. http://dx.doi.org/10.14419/ijet.v7i4.24.21761.

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Bulk electrical power generation is generated using fossil fuels which emit huge pollution which is a global constraint today. Non-conventional sources of energy are the alternative energy sources for power generation. Non-conventional sources like PV (photo-voltaic) system are used as power source now-a-days. Multi-level inverters (MLI) are dominating inverter circuits giving out voltage with less distortion eventually reducing voltage stress on switches and size of filter. This paper presents a MLI structure with five switches giving out five-level output from the inverter. PV system is used as source and boost converter amplifies the PV output voltage to desired value. The paper presents a simplified PWM (pulse width modulation) technique for PV fed five switch five-level inverter. The proposed system is developed and results are obtained using MATLAB/SIMULINK software. Results are presented for the system considering R-load and RL-load conditions.

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LAABIDI, Houda, Houda JOUINI, and Abdelkader MAMI. "Performance Analysis of MPC Controller Applied for Hybrid PV-Wind Under Varying Weather Conditions." International Journal on Electrical Engineering and Informatics 12, no. 4 (December 31, 2020): 979–1000. http://dx.doi.org/10.15676/ijeei.2020.12.4.17.

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The studied system contains a photovoltaic conversion chain with a total power of 7.2 kW, a wind conversion chain (5.1 kW), two-level inverter related to the electrical grid through an RL filter. The control systems of the simulation model include the Model Predictive Controller (MPC), which is mainly applied for both DC/DC converters and three-phase inverter. The MPC strategy uses the mathematical model of the considered power converters in order to predict the possible future behaviors of the different controlled variables. It permits selecting the optimal voltage vector, which is able to ensure a minimization of the specified cost function. Modeling and simulation are achieved using PSIM software in order to verify the system’s performances, highlighting many scenarios of varying meteorological conditions. The simulation responses prove that the proposed MPC algorithm can offer a fast transient response, an accurate reference tracking, a high-injected power quality with a low current THD (less than 1% in the steady state).

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Silk, Ely. "Low-Cost Hot Stage For Crystal Studies." Microscopy Today 6, no. 3 (April 1998): 8–9. http://dx.doi.org/10.1017/s1551929500066748.

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I required a hot stage to do some work with iiquid crystals. Hot stages on the market are very expensive. I decided to try using electro-conductive glass, This is the NESA glass used by automotive manufacturers in electrically operated defrosting windows, A local glazier ordered some of the glass for me in 8 x 8 inch squares, i had the squares cut and edge polished into 2 x 2 inch pieces by a filter manufacturer. One sheet of 8 x 8 inch glass cost me about $15.00. Cut down, I got nine 2 x 2 inch pieces suitable for my experiments at an additional cost of $3.00 per cut piece.A piece of 2 x 2 inch electro-conductive glass is prepared with two thin copper strips epoxied to the outer margins. One needs a conductive epoxy, and i used a silver epoxy (40-3900 resin and catalyst) obtained from Epoxies, Etc. of Greenville, Rl.

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Abouloifa, Abdelmajid, Karim Noussi, Elhoussin Elbouchikhi, Hanane Katir, Ibtissam Lachkar, and Abdelali El Aroudi. "High-Gain Observer-Based Advanced Nonlinear Control of a Grid-Connected Wind Energy Conversion System with Sensorless Maximum Power Point Tracking." Machines 10, no. 11 (November 14, 2022): 1074. http://dx.doi.org/10.3390/machines10111074.

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This paper deals with the control development of a wind energy conversion system (WECS) interfaced to a utility grid by using a doubly fed induction generator (DFIG), a back-to-back (B2B) converter and an RL filter for optimal power extraction. The aim was to design a sensorless controller to improve the system reliability and to simultaneously achieve the regulation of the generator speed, reactive power and DC-link voltage. The proposed global control scheme combines: (i) a high-gain observer employed to estimate the generator speed and the mechanical torque, usually regarded as accessible, (ii) a sensorless MPPT block developed to provide optimal generator speed reference, which is designed on the basis of the mechanical observer and a polynomial wind-speed estimator and (iii) a finite-time controller (FTC) applied to the B2B converter to meet the output reference’s tracking objectives in a short predefined finite time by using the backstepping and Lyapunov approaches. The proposed controller performance is formally analysed, and its capabilities are verified by numerical simulations using a 2 MW DFIG wind turbine (WT) under different operating conditions.

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Panati, Poornima Udaychandra, Sridhar Ramasamy, Mominul Ahsan, Julfikar Haider, and Eduardo M. G. Rodrigues. "Indirect Effective Controlled Split Source Inverter-Based Parallel Active Power Filter for Enhancing Power Quality." Electronics 10, no. 8 (April 8, 2021): 892. http://dx.doi.org/10.3390/electronics10080892.

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The existing solutions for reducing total harmonic distortion (THD) using different control algorithms in shunt active power filters (SAPFs) are complex. This work proposes a split source inverter (SSI)-based SAPF for improving the power quality in a nonlinear load system. The advantage of the SSI topology is that it is of a single stage boost inverter with an inductor and capacitor where the conventional two stages with an intermediate DC-DC conversion stage is discarded. This research proposes inventive control schemes for SAPF having two control loops; the outer control loop regulates the DC link voltage whereas the inner current loop shapes the source current profile. The control mechanism implemented here is an effective, less complex, indirect scheme compared to the existing time domain control algorithms. Here, an intelligent fuzzy logic control regulates the DC link voltage which facilitates reference current generation for the current control scheme. The simulation of the said system was carried out in a MATLAB/Simulink environment. The simulations were carried out for different load conditions (RL and RC) using a fuzzy logic controller (FLC) and PI controllers in the outer loop (voltage control) and hysteresis current controller (HCC) and sinusoidal pulse width modulation (SPWM) in the inner loop (current control). The simulation results were extracted for dynamic load conditions and the results demonstrated that the THD can be reduced to 0.76% using a combination of SPWM and FLC. Therefore, the proposed system proved to be effective and viable for reducing THD. This system would be highly applicable for renewable energy power generation such as Photovoltaic (PV) and Fuel cell (FC).

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Mikhail, Pustovetov. "Loaded by RL-Branch EMC Filter on the Output of the Inverter Transfer Function Taking into Account Resistances and Electric Transformer’s Transfer Function Derivation." Journal of Engineering Research and Sciences 1, no. 5 (May 2022): 102–8. http://dx.doi.org/10.55708/js0105011.

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Aithal, Suhas, Jagmohan S. V., and Niveditha S. "Knowledge and attitude of nursing staff towards nebulization therapy in a tertiary care hospital." International Journal of Research in Medical Sciences 5, no. 9 (August 26, 2017): 3976. http://dx.doi.org/10.18203/2320-6012.ijrms20173965.

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Background: Nebulization is an important tool in the treatment of respiratory conditions. Nurses are primary health care providers for using the nebulizers in a hospital setting. The examination of nurse's knowledge and performance regarding the nebulizer therapy is of utmost importance for proper nebulization. Aim of the study was to access the knowledge and attitude of staff nurses towards nebulization therapy.Methods: A cross sectional study was conducted at the RL Jalappa hospital, Kolar, Karnataka, India. 50 nurses working the intensive care units and wards were given a questionnaire regarding the key aspects of nebulization therapy. A workshop was then conducted for the same participants on correct nebulization techniques and the questionnaire was given and the results post workshop was analyzed.Results: In pre-study, most nurses had unsatisfactory knowledge with respect to breathing pattern during nebulization (72.2%), types of masks used (83.3%), changing of filter (62.5%). On comparing satisfactory knowledge level of nurses pre-and post, it was found statistically significant increase in knowledge for breathing pattern during nebulization, knowledge of types of nebulization, nebulization time, nebulization end point, types of drugs used, type of dilution, proportion of dilution, ideal volume of drugs in medication, replacement of tubing, changing of filter, types of disinfections used, types of nebulization and types of mask (p <0.05).Conclusions: The knowledge of the staff nurses regarding the nebulization therapy was unsatisfactory which was reflected by improvement in the knowledge post workshop training. The staff nurses should be provided periodic training on nebulization therapy to give effective and safe care to patients.

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Kasim, Mostafa Q., and Raaed Faleh Hassan. "Model Predictive Current Control with Asymmetric Stacked Multilevel Inverter and LCL-Filter Based STATCOM." Journal of Techniques 3, no. 2 (June 30, 2021): 19–30. http://dx.doi.org/10.51173/jt.v3i2.305.

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The work presented in this paper deals with a proposal of a new topology of a multilevel inverter to act as a Static synchronous Compensator (STATCOM). The proposed inverter is the five-level Asymmetric Stacked Multi-Level Inverter (ASMLI). One of the essential features of this inverter that distinguishes it from the conventional types is that it achieves the required voltage levels with fewer switching devices, leading to simplifying the control process. Moreover, the work includes using a Finite Control Set Model Predictive Current Control (FCS-MPCC) to control the proposed structure. The FCS-MPCC control strategy performs the finite optimization process at the current sampling instant to provide the optimum switching states to the inverter at the next sampling instant. Therefore, this control strategy allows injecting harmonic current and reactive power compensation to reduce source current distortion and improve the voltage profile and power factor. The optimization mechanism reduces the cost function, which is a function of measuring the network current's deviation from the reference value and how the capacitor voltage deviates from the required values. LCL-filter was used to connect this setup to the grid, and its resonance was actively damped using the multivariable capabilities of the FCS-MPCC. The proposed control framework was simulated using MATLAB/Simulink 9.1 environment and tested in a distorted and healthy network compared to a conventional two-level converter with RL-filter. The STATCOM was used to inject reactive power to raise the source power factor to unity and reduce source current harmonics by injecting harmonic current. The proposed prototype could absorb 70% of source current harmonics, which is nearly 25% better than a conventional inverter, inject an appropriate amount of reactive power, and raise the source power factor to unity in two case scenarios. The performance achieved was promising at steady-state operation and speedy response during transients with balanced capacitors voltages.

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48

Feng, Xingxing, Hong Chen, Gang Wu, Anfu Zhang, and Zhigao Zhao. "A New Vibration Controller Design Method Using Reinforcement Learning and FIR Filters: A Numerical and Experimental Study." Applied Sciences 12, no. 19 (September 30, 2022): 9869. http://dx.doi.org/10.3390/app12199869.

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High-dimensional high-frequency continuous-vibration control problems often have very complex dynamic behaviors. It is difficult for the conventional control methods to obtain appropriate control laws from such complex systems to suppress the vibration. This paper proposes a new vibration controller by using reinforcement learning (RL) and a finite-impulse-response (FIR) filter. First, a simulator with enough physical fidelity was built for the vibration system. Then, the deep deterministic policy gradient (DDPG) algorithm interacted with the simulator to find a near-optimal control policy to meet the specified goals. Finally, the control policy, represented as a neural network, was run directly on a controller in real-world experiments with high-dimensional and high-frequency dynamics. The simulation results show that the maximum peak values of the power-spectrum-density (PSD) curves at specific frequencies can be reduced by over 63%. The experimental results show that the peak values of the PSD curves at specific frequencies were reduced by more than 47% (maximum over 52%). The numerical and experimental results indicate that the proposed controller can significantly attenuate various vibrations within the range from 50 Hz to 60 Hz.

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Li, Wei, Yuan Jiang, Xiaoliang Zhang, Fangfang Dang, Feng Gao, Haomin Wang, and Qi Fan. "Reliability Assurance Dynamic SSC Placement Using Reinforcement Learning." Information 13, no. 2 (January 21, 2022): 53. http://dx.doi.org/10.3390/info13020053.

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Software-defined networking (SDN) and network function virtualization (NFV) make a network programmable, resulting in a more flexible and agile network. An important and promising application for these two technologies is network security, where they can dynamically chain virtual security functions (VSFs), such as firewalls, intrusion detection systems, and intrusion prevention systems, and thus inspect, monitor, or filter traffic flows in cloud data center networks. In view of the strict delay constraints of security services and the high failure probability of VSFs, we propose the use of a security service chain (SSC) orchestration algorithm that is latency aware with reliability assurance (LARA). This algorithm includes an SSC orchestration module and VSF backup module. We first use a reinforcement learning (RL) based Q-learning algorithm to achieve efficient SSC orchestration and try to reduce the end-to-end delay of services. Then, we measure the importance of the physical nodes carrying the VSF instance and backup VSF according to the node importance of VSF. Extensive simulation results indicate that the LARA algorithm is more effective in reducing delay and ensuring reliability compared with other algorithms.

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50

Yang, Ningning, Cheng Xu, Chaojun Wu, Rong Jia, and Chongxin Liu. "Dynamic Behaviors and the Equivalent Realization of a Novel Fractional-Order Memristor-Based Chaotic Circuit." Complexity 2018 (December 2, 2018): 1–13. http://dx.doi.org/10.1155/2018/9467435.

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This paper proposed a novel fractional-order memristor-based chaotic circuit. A memristive diode bridge cascaded with a fractional-order RL filter constitutes the generalized fractional-order memristor. The mathematical model of the proposed fractional-order chaotic circuit is established by extending the nonlinear capacitor and inductor in the memristive chaotic circuit to the fractional order. Detailed theoretical analysis and numerical simulations are carried out on the dynamic behavior of the proposed circuit by investigating the stability of equilibrium points and the influence of circuit parameters on bifurcations. The results show that the order of the fractional-order circuit has a great influence on the dynamical behavior of the system. The system may exhibit complicated nonlinear dynamic behavior such as bifurcation and chaos with the change of the order. The equivalent circuits of the fractional-order inductor and capacitor are also given in the paper, and the parameters of the equivalent circuits are solved by an undetermined coefficient method. Circuit simulations of the equivalent fractional-order memristive chaotic circuit are carried out in order to validate the correctness of numerical simulations and the practicability of using the integer-order equivalent circuit to substitute the fractional-order element.

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Journal articles on the topic 'RL filter'

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