Satisfactory Control Research Articles

Generalized Malmquist orthogonal functions based model predictive control

The computational burden could be an issue of traditional model predictive control (MPC) in real-time applications. There are different procedures to cope with this problem such as using explicit MPC or approximation of the control inputs using orthogonal-basis functions. This paper presents the design procedure and experimental validation of a generalized discrete-time Malmquist orthogonal functions-based model predictive control (MbMPC) whose usage can decrease calculation concerns. To the authors’ knowledge, this is the first time the Malmquist functions are introduced into the MPC design. The discrete-time orthogonal Malmquist functions properties are used within this approach for approximating the future control input increments with a smaller number of parameters than in traditional MPC approaches. It is shown that the satisfactory controller and closed-loop system performances can be achieved using smaller number of tuning parameters. The performance of the proposed MbMPC is shown and compared with discrete-time Laguerre orthogonal functions based MPC (LbMPC) applied to a DC motor servo system. The simulation and experimental results demonstrate better IAE, ITAE, ISE and ITSE controller performance indices as well as faster average calculation time in comparison with the LbMPC approach. Additionally, the advantage of using the proposed method is emphasized by showing how the length of the prediction horizon affects the computational burden in comparison to the traditional MPC approaches.

Synergistic growth suppression of Fusarium oxysporum MLY127 through Dimethachlon Nanoencapsulation and co-application with Bacillus velezensis MLY71

Fusarium oxysporum is a destructive plant pathogen with robust survival mechanisms, complicating control efforts. This study aimed to develop nanoformulated fungicides, screen antagonistic bacteria, and evaluate their combined efficacy. A novel self-emulsifying nanoemulsion (DZW) was formulated using zein and benzaldehyde-modified wheat gluten (BgWG) as carriers for dimethachlon (DTN). The preparation process optimized material ratios and emulsification techniques. Concurrently, antagonistic bacterial strains against F. oxysporum were screened via the plate standoff method, identifying Bacillus velezensis MLY71 as both antagonistic and compatible with DTN. The DZW nanoemulsion achieved a particle size of 93.22 nm, an encapsulation efficiency (EE) of 90.57%, and a DTN loading capacity (LC) of 67.09%, with sustained release over 96 h. The combination of DTN (0.04 mg·mL⁻¹) and B. velezensis MLY71 (1 × 10⁴ CFU·mL⁻¹) achieved a 76.66% inhibition rate against F. oxysporum MLY127, 1.71 times greater than DTN alone, indicating significant synergy. At a DTN concentration of 0.20 mg·mL⁻¹, the combination of DZW and MLY71 showed a synergy coefficient of 1.33. This synergy was also observed in soil environments, indicating its adaptability for controlling soil-borne pathogens. As sustainable management continues to gain attention in agricultural disease control, this study offers a promising strategy for achieving higher efficacy with the same fungicide dose or satisfactory control with reduced fungicide application. The excellent drug-loading performance of BgWG also expanded the applications of the wheat by-product gluten.

Dublin down on detection: Understanding Salmonella Dublin in British Columbia through bulk tank milk surveillance.

Increased cases of Salmonella Dublin, a bacterial pathogen that primarily affects dairy cattle, have been noted in British Columbia (BC), Canada since 2015. The objective of this cross-sectional study was to 1) understand the prevalence and distribution of S. Dublin in BC dairy farms based on bulk tank milk (BTM) serology, 2) to investigate the degree of variability within percent positivity (%PP) in negative and positive farms, and 3) investigate risk factors associated with positivity. All BC dairy herds' BTM was sampled 4 times from September 2021 to April 2023 to determine S. Dublin positivity (at least one result ≥35% percent positivity on BTM serology). Of the 461 herds sampled 137 (30%) were positive. A multivariable logistic regression model identified 3 risk factors associated with herd level positivity. Specifically, herds with 200 to 500 lactating cattle (OR = 2.42, 95% CI = 1.14-5.36) and herds with > 500 lactating cattle (OR = 21.78, CI = 5.14-152.20) were associated with increased risk of S. Dublin herd level positivity. Farms that had greater than 5 farms within 4 km radius (OR = 1.73, 95% CI = 1.05-2.90) were at greater risk for S. Dublin compared with those with 5 or fewer. Having satisfactory pest control was protective against S. Dublin positivity (OR = 0.28, 95% CI = 0.09-0.80). Percent positivity variability varied greatly among negative, indeterminant (15-34%PP), and positive farms. Negative farms experienced very little variability in %PP (Median = 5.79%, IQR = 3.86%), with variability increasing among the indeterminant farms (Median = 16.04%, IQR = 11.94%) and highest among the positive farms (Median = 35.84%, IQR = 31.59%). Monitoring variability of BTM %PP could function as an accessible early warning tool for producers and veterinarians to predict if their herds may become positive.

Oxymatrine-based insecticide: A natural product for the control of stored-product beetle pests in wheat grain

Insecticides of natural origin are a promising alternative to synthetic insecticides. Therefore, the intention of this study was to evaluate the potential of the natural product oxymatrine, as a wheat grain protectant against major stored-product beetle pests. The insecticidal activity of oxymatrine was tested against Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrichidae), Sitophilus granarius (Linnaeus, 1758) (Coleoptera: Curculionidae), Sitophilus oryzae (Linnaeus, 1763) (Coleoptera: Curculionidae), Tribolium confusum (Jacquelin du Val, 1868) (Coleoptera: Tenebrionidae) and Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae) at doses of 0.25, 0.5, 1, 2 and 4 mg a.i./kg (ppm) of wheat grain. Initial mortality was assessed after 2, 7 and 14 days of exposure, and total mortality after 7 days of recovery period. The impact on progeny production/reduction was assessed for all species, while in the case of R. dominica and Sitophilus species related weight loss and frass production were also documented. The results show that species, dose, exposure and the recovery period significantly affect the effectiveness of oxymatrine. All doses of oxymatrine provided complete mortality of R. dominica after 7 days of exposure and 7 days of recovery. The satisfactory control of Sitophilus species and T. castaneum was achieved by 1 mg/kg and T. confusum by 4 mg/kg after 14 days of exposure and 7 days of recovery. Oxymatrine complete suppressed progeny production and prevented damage by R. dominica after all exposure intervals. The lowest number of progeny of Sitophilus and Tribolium species and damage by Sitophilus species was recorded after 14 days of exposure in wheat treated with ≥1 mg/kg of oxymatrine. The obtained results indicate that oxymatrine could be an efficient natural product for the control of stored-product beetles in stored wheat.

A Retrospective Review of Ambulatory Oral and Maxillofacial Surgery in a Suburban Tertiary Hospital in Nigeria

Background Ambulatory surgical procedures are integral aspects of oral and maxillofacial surgical (OMS) practice. Objective The aim of this study is to report the scope of ambulatory OMS procedures in a Nigerian suburban teaching hospital. Method A retrospective review of ambulatory OMS procedures performed at Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria, between March 2021 and February 2022 was conducted. Sociodemographic data, diagnoses, procedures, type of anesthesia, and immediate postoperative complications were retrieved from patients' records. Data were analyzed using the Statistical Package of Social Sciences (SPSS) version 22. Results Two hundred and fifty-two ambulatory OMS procedures were performed during the 12-month study period. This accounted for 80.3% (252/314) of elective surgeries. The patients' mean (standard deviation [SD]) age was 32.2 (10.4) years, while a slight male preponderance (51.6%) was recorded. Third molar surgery was the commonest (48.0%) procedure undertaken in ambulatory setting. Most (90.9%) of them were performed under local anesthesia. Satisfactory postoperative pain control was achieved with the use of oral nonsteroidal anti-inflammatory analgesics in most patients (81.7%). However, owing to a failed ambulatory session, there was an eventual admission rate of 0.4% (1/252). Conclusion Ambulatory surgical procedures constitute the majority of the OMS elective cases, with third molar surgery being the commonest procedure. Judicious prescription and administration of oral analgesics were effective in managing postoperative pain in our day case OMS patients. We recommend a prospective study to determine an intermediate/long-term outcome of care in ambulatory settings.

Stable transfer learning-based control: An off-dynamics adaptive approach for unknown nonlinear systems

Although data-driven control can achieve satisfactory control performance without relying on the system’s mathematical model (i.e., model-free), extensive online interaction with the real system remains necessary. This interaction-intensive nature has become a barrier to the widespread use of data-driven control. In fact, training a controller on the system from scratch is usually infeasible due to limited data availability and safety reasons. This paper aims to mitigate this drawback while still preserving the model-free feature of data-driven control with help of transfer learning. Specifically, a controller transfer learning problem is considered for nonlinear systems with unknown dynamics, a topic underexplored in the literature. The proposed method can transfer the controller trained on the source system directly to the target system without further tuning. It is firstly be revealed that the transfer map for this problem is a dynamic system coupled with the control law, which is learned by constructing an auxiliary system in a data-driven manner. Then, the off-dynamics adaptive law is designed to train the controller using the Lyapunov stability theory. Furthermore, our method is extended to a class of higher-order nonlinear systems with stability guarantees. Finally, the stability and reliability of the method are investigated through both rigorous theoretical analysis and illustrative examples. The results demonstrate that our method successfully transfers the tracking controller between two unknown and different nonlinear systems with stability guarantees.

A cable-based tuned inerter damper for edgewise vibration control of the wind turbine blade

As wind turbines grow larger, with longer blades aimed at enhancing wind energy conversion efficiency, the accompanying increase also results in heightened vibration, thereby posing safety challenges to the structure. The cable-based method, requiring limited stroke and installation space while ensuring satisfactory control performance, is an emerging vibration control strategy in these structures. This study evaluates the efficacy of a wind blade-suited cable-based tuned inerter damper (CTID) in mitigating edgewise vibrations. The CTID comprises inerter, damping, and spring elements, anchored at the hub and connected to the blade tip through a cable. First, the multi-degree-of-freedom blade-CTID coupled model is established. Subsequently, the wind load spectrum of the rotating blade is derived by considering the rotational Fourier spectrum of wind speeds acting on the blade. The pseudo excitation method facilitates stochastic response analysis under wind loads, while particle swarm optimization identifies optimal CTID parameters. The effectiveness of the CTID is numerically validated through a comparison with the conventional tuned mass damper, demonstrating its superior vibration mitigation performance and less on-demand stroke. The associated practical issues of the CTID are discussed, such as the axial cable force-induced instability and buckling issues. The numerical results of this study proved the effectiveness and practicability of rotating blade-suited CTID, providing a novel and promising vibration control strategy in limited-space structures.

ECG-based epileptic seizure prediction: Challenges of current data-driven models.

Up to a third of patients with epilepsy fail to achieve satisfactory seizure control. A reliable method of predicting seizures would alleviate psychological and physical impact. Dysregulation in heart rate variability (HRV) has been found to precede epileptic seizures and may serve as an extracerebral predictive biomarker. This study aims to identify the preictal HRV dynamics and unveil the factors impeding the clinical application of ECG-based seizure prediction. Thirty-nine adult patients (eight women; median age: 38, [IQR = 31, 56.5]) with 252 seizures were included. Each patient had more than three recorded epileptic seizures, each at least 2 hours apart. For each seizure, one hour of ECG prior to seizure onset was analyzed and 97 HRV features were extracted from overlapping three-minute windows with 10s stride. Two separate patient-specific experiments were performed using a support vector machine (SVM). Firstly, the separability of training data was examined in a non-causal trial. Secondly, the prediction was attempted in pseudo-prospective conditions. Finally, visualized HRV data, clinical metadata, and results were correlated. The mean receiver operating characteristic (ROC) area under the curve (AUC) for the non-causal experiment was 0.823 (±0.12), with 208 (82.5%) seizures achieving an improvement over chance (IoC) classification score (p < 0.05, Hanley & McNeil test). In pseudo-prospective classification, the ROC-AUC was 0.569 (±0.17), and 86 (49.4%) seizures were classified with IoC. Off-sample optimized SVMs failed to improve performance. Major limiting factors identified include non-stationarity, variable preictal duration and dynamics. The latter is expressed as both inter-seizure onset zone (SOZ) and intra-SOZ variability. The pseudo-prospective preictal classification achieving IoC in approximately half of tested seizures suggests the presence of genuine preictal HRV dynamics, but the overall performance does not warrant clinical application at present. The limiting factors identified are often overlooked in non-causal study designs. While current deterministic prediction methods prove inadequate, probabilistic approaches may offer a promising alternative. Many patients with epilepsy suffer from uncontrollable seizures and would greatly benefit from a reliable seizure prediction method. Currently, no such system is available to meet this need. Previous studies suggest that changes in the electrocardiogram (ECG) precede seizures by several minutes. In our work, we evaluated whether variations in heart rate could be used to predict epileptic seizures. Our findings indicate that we are still far from achieving results suitable for clinical application and highlight several limiting factors of present seizure prediction approaches.

A Novel Ungrounded Haptic Device for Generation and Orientation of Force and Torque Feedbacks.

To provide deeper immersion for the user in the virtual environments, both force and torque feedbacks are required rather than the mere use of visual and auditory ones. In this paper, we develop a novel propeller-based Ungrounded Handheld Haptic Device (UHHD) that delivers both force and torque feedbacks in one device to help the user experience a realistic sensation of immersion in a three-dimensional (3D) space. The proposed UHHD uses only a pair of propellers and a set of sliders to continuously generate the desired force and torque feedbacks up to 15N and 1N.m in magnitude in less than 370ms, respectively. The produced force and torque feedbacks are oriented in a desired direction using a gimbal mechanism where the propellers are mounted inside in such a way that a simple structure is obtained. These features facilitate the control of the proposed UHHD and enhance its practicality in various applications. To prove the capability of the system, we model it and elaborate on the force and torque analyses. Next, we develop a robust parallel force/position controller to tackle the structured and unstructured uncertainties. Finally, a measurement setup is manufactured to experimentally evaluate the performance of the UHHD and the controller. The implementation of the controller on the developed UHHD prototype shows that a satisfactory control performance is achievable in terms of offering the desired force and torque feedbacks.

Active disturbance rejection control of pressurizer pressure during startup process in a pressurized water reactor nuclear power plant

To cope with the participation of power plant peak shaving and realize the diversification of nuclear energy applications including cogeneration, desalination, etc. The application of automatic procedure startup and shutdown system (APS) is an important research direction to improve the safety, economy and flexibility of pressurized water reactor (PWR) nuclear power plant (NPP). But it is difficult to realize automatic control of pressurizer pressure in the PWR NPP startup condition with drastic changes and disturbances. To solve this problem, an active disturbance rejection control (ADRC) algorithm was proposed for the pressure control of the pressurizer. The controller parameters were tuned based on a two-step tuning scheme. Its control performance and disturbance rejection ability were studied and compared with proportional-integral-derivative (PID) controller under different operation conditions. The simulation results showed that the designed controller with fixed parameters can outperform the PID controller with specific optimized parameters on setpoint tracking and disturbance rejection. This study is of great significance for realizing the automatic control of pressurizer pressure in the startup process, and can provide reference for the design of the automatic control system during PWR startup. The controller was applied in typical startup process and achieved satisfactory control performance.

Simulation analysis and experimental research on static performance of water-hydraulic pressure difference control valve

Many hydraulic tools, like hydraulic cylinders and hydraulic artificial muscle joints are operated by adjusting pressure differences between different zones. Typically, the method employed to change the pressure difference is establishing hydraulic bridges and adjusting liquid resistance. While effective, this method's drawback is complex structures. To address this issue, a water-hydraulic pressure difference control valve, integrating two hydraulic bridges, was designed. The static performances including the output pressure difference, the flow rate and the force acting on the valve core were analyzed using AMESim and computational fluid dynamics simulations. Based on the simulation results, a prototype of voice coil motor direct drive pressure difference control valve was manufactured and the corresponding experiments were carried out. The computational fluid dynamics simulation results show that the internal leakage and the through-flow capacity difference between throttling grooves affect the flow field characteristics of the valve. When the pump pressure is 3 MPa and the valve opening is at the middle position, the internal leakage increases the flow rate from 2.25 L/min to 2.38 L/min, and the through-flow capacity difference reduces the control port pressure from the theoretical analysis of 1.5 MPa–1.41 MPa. Furthermore, combined with the analysis of the external liquid resistance, the AMESim model of the pressure difference control valve is modified. When the pump pressure is 3 MPa, the pressure difference and flow rate average deviations between the modified AMESim model and the experiment are 0.021 MPa and 0.048 L/min. Finally, a rotational angle experiment for a water hydraulic artificial muscle joints showed satisfactory control effects, suggesting the valve's application in controlling hydraulic tools and actuators.

Evaluation of postoperative outcomes after cataract surgery in patients with Juvenile Idiopathic Arthritis-Associated Uveitis.

To evaluate the postoperative outcomes of cataract surgery and intraocular lens (IOL) implantation on visual outcomes and complications in pediatric patients with Juvenile Idiopathic Arthritis-Associated Uveitis. This study included 25 patients (30 eyes) with uveitis and cataracts who underwent cataract surgery. The study was conducted as a retrospective study. Patients were divided into two groups based on their preoperative treatment: those who received immunomodulatory therapy (IMT) along with systemic corticosteroids and those who received IMT in combination with a biologic therapy. Best corrected visual acuity (BCVA), intraocular pressure (IOP), central macular thickness (CMT), macular volume (MV), and postoperative complications were assessed at various time points up to 12 months. All surgeries were performed by a single surgeon. Significant improvement in BCVA were observed postoperatively in both study groups, with approximately 80% of eyes showing improvement. Mean BCVA improved from 0.89 ± 0.63 to 0.37 ± 0.33 in group 1and from 0.82 ± 0.68 to 0.35 ± 0.31 in group 2 after 12 months. Postoperatively, there was a decrease in mean IOP, with no significant variance observed between the two groups. Complications were observed in 73% of cases, including posterior capsular opacification (PCO), secondary glaucoma, and macular edema (ME), but did not significantly differ between groups. Cataract surgery in children with uveitis associated with JIA presents significant challenges due to the risk of postoperative complications, even with adequate preoperative and postoperative care. The similar improvement in BCVA observed in both groups suggests that different systemic therapies were sufficient for satisfactory control of inflammation before and after surgery.

System modeling and fuzzy adaptive PI sliding-mode control of a novel ship-mounted cable-based bulkhead cleaning robot

Ship cleaning poses significant risks and consumes considerable time, primarily due to the irregular hull surface geometry and the unpredictable ship motion induced by wave excitation. To address this challenge and achieve efficient, autonomous cleaning, a spatial variable structure cable-based bulkhead cleaning robot (SC-R) is proposed. Unlike traditional cable-driven parallel mechanisms (CDPMs), SC-R operates in a non-inertial frame, whereby its motion is subject to continuous and unpredictable ship motion. Consequently, SC-R exhibits intricate dynamic characteristics, posing a significant hurdle for controller design. To solve this problem, a sliding-mode controller is proposed for SC-R. Specifically, the dynamic model of SC-R, which includes ship motion and various disturbing forces, is systematically established using the Newton-Euler method. Furthermore, a fuzzy adaptive PI sliding-mode controller (FAPI-SMC) is specifically proposed to enhance the convergence speed and robustness of SC-R. The stability of the closed-loop system is analyzed using Lyapunov theory, and the tracking error is proved to be eventually bounded. Finally, the availability of this theory is confirmed by simulation and experiment. It is shown that FAPI-SMC can achieve a satisfactory control effect in practice.

A novel satisfactory model predictive control based on current variance for high power three‐level‐NPC rectifiers

AbstractHere, a novel satisfactory model predictive control based on current variance (CV‐SMPC) is proposed for three level neutral point clamped (NPC) rectifiers. CV‐SMPC achieves global optimization of multiple control objectives rather than optimal control of a single control objective with the satisfaction interval. The current satisfaction interval is adjusted online based on the current variance in the CV‐SMPC. The relationship between the current total harmonic distortion (THD), switching frequency, and current variance is established through experimental investigation, enhancing the comprehensibility of control effects. In addition, three simplified sets of candidate vectors are proposed based on the voltage satisfaction interval, thereby reducing the computational burden. Furthermore, the control objectives are categorized into three levels and sequentially combined, eliminating the laborious process of adjusting the weighting factors. Finally, the experimental results conclusively demonstrate the exceptional control performance of CV‐SMPC in both steady‐state and dynamic processes.

Clinical outcomes analysis of image-guided brachytherapy as definitive treatment for inoperable endometrial cancer

ObjectivesThis study evaluates the efficacy and toxicity of image-guided brachytherapy combined with or without external beam radiotherapy (IGBT ± EBRT) as definitive treatment for patients with inoperable endometrial cancer (IOEC), in addition to establishing a risk classification to predict prognosis.MethodsFifty-one IOEC patients who underwent IGBT ± EBRT at Peking Union Medical College Hospital from January 2012 to December 2021 were retrospectively analyzed, of which 42 patients (82.4%) were treated with IGBT + EBRT and 9 patients (17.6%) with IGBT alone. Establishing risk classification based on FIGO 2009 staging and biopsy pathology, stage III/IV, non-endometrioid, or Grade 3 endometrioid cancer were included in the high-risk group (n = 25), and stage I/II with Grade 1–2 endometrioid cancer was included in the low-risk group (n = 26).ResultsThe median follow-up time was 58.0 months (IQR, 37.0–69.0). Clinical complete remission (CR) was achieved in 92.2% of patients after radiotherapy (n = 47). The cumulative incidences of locoregional and distant failure were 19.6% (n = 10) and 7.8% (n = 4), respectively. A total of 20 patients died (39.2%), including 10 cancer-related deaths (19.6%) and 10 comorbidity-related deaths (19.6%). The 5-year locoregional control (LRC), time to progression (TTP), overall survival (OS), and cancer-specific survival (CSS) were 76.9%, 71.2%, 59.4%, and 77.0%, respectively. No Grade 3 or above acute or late toxicities were reported. In univariate analysis, LRC, TTP, and CSS were significantly higher in the low-risk group than in the high-risk group (P < 0.05). After adjusting for age, number of comorbidities, radiotherapy modality, and chemotherapy, the low-risk group was still significantly better than the high-risk group in terms of LRC (HR = 6.10, 95% CI: 1.18–31.45, P = 0.031), TTP (HR = 8.07, 95% CI: 1.64–39.68, P = 0.010) and CSS (HR = 6.29, 95% CI: 1.19–33.10, P = 0.030).ConclusionsIGBT ± EBRT is safe and effective as definitive treatment for IOEC patients, achieving satisfactory locoregional control, favorable survival outcomes, and low toxicity. Risk classification based on FIGO 2009 staging and biopsy pathology is an independent prognostic factor for LRC, TTP, and CSS.

Characteristics, treatment, and outcomes of spontaneous renal artery dissection: a 10-year retrospective single-center experience.

Spontaneous renal artery dissection (SRAD) is a rare cause of renal failure and renovascular hypertension, with the diagnosis often being delayed and treatment varying across different centers. The objective of this retrospective cohort study was to scrutinize the characteristics, treatment modalities, and outcomes of patients with SRAD at our center over the past ten years. Furthermore, the study sought to identify the most suitable treatment options for different categories of patients with SRAD. Data from 21 consecutive patients who presented with symptoms of SRAD from December 2013 to December 2023 were collected. Lesion characteristics, treatment options, blood pressure (BP) control, serum creatinine and estimated glomerular filtration rate (eGFR) were analyzed. A paired t-test was used for comparisons of BP, serum creatinine, and eGFR. An independent samples t-test was used to analyze baseline BP and BP change in different treatment groups. The mean age, weight, and height of patients with SRAD was 49.2±13.0 (range, 18-69) years, 69.0±9.7 (range, 50-80) kg, and 1.7±0.1 (range 1.6-1.8) m, respectively. New-onset hypertension was found in 8 (38.1%) patients. Renal artery dissecting aneurysm and renal artery stenosis were found in 1 (4.8%) and 4 (19.0%) patients, respectively. Supportive medical treatment alone, endovascular intervention, and nephrectomy were required in 15, 4 and 2 cases, respectively. Stable renal function and satisfactory hypertension control were obtained in all treatment groups, with a median follow-up of 18.1 (range, 12-32) months. Medical management is a reasonable choice in most patients with SRAD. Interventional management is an efficacious strategy for the management of renovascular hypertension and the preservation of renal function.

Active control of transonic airfoil flutter using synthetic jets through deep reinforcement learning

This paper presents a novel framework for the active control of transonic airfoil flutter using synthetic jets through deep reinforcement learning (DRL). The research, conducted in a wide range of Mach numbers and flutter velocities, involves an elastically mounted airfoil with two degrees of freedom of pitching and plunging oscillations, subjected to transonic flow conditions at varying Mach numbers. Synthetic jets with zero-mass flux are strategically placed on the airfoil's upper and lower surfaces. This fluid–structure interaction (FSI) problem is treated as the learning environment and is addressed by using the arbitrary Lagrangian–Eulerian lattice Boltzmann flux solver (ALE-LBFS) coupled with a structural solver on dynamic meshes. DRL strategies with proximal policy optimization agents are introduced and trained, based on the velocities probed around the airfoil and the dynamic responses of the structure. The results demonstrate that the pitching and plunging motions of the airfoil in the limited cycle oscillation (LCO) can be effectively alleviated across an extended range of Mach numbers and critical flutter velocities beyond the initial training conditions for control onset. Furthermore, the aerodynamic performance of the airfoil is also enhanced, with an increase in lift coefficient and a reduction in drag coefficient. Even in previously unseen environments with higher flutter velocities, the present strategy is achievable satisfactory control results, including an extended flutter boundary and a reduction in the transonic dip phenomenon. This work underscores the potential of DRL in addressing complex flow control challenges and highlights its potential to expedite the application of DRL in transonic flutter control for aeronautical applications.

Deep brain stimulation of the subthalamic nucleus for a patient with drug resistant juvenile myoclonic epilepsy: 1year follow-up.

Drug-resistant juvenile myoclonic epilepsy (DR-JME) remains a significant challenge in neurology. Traditional management strategies often fail to achieve satisfactory control, necessitating innovative treatments. This case report aims to evaluate the efficacy and safety of deep brain stimulation (DBS) targeting the subthalamic nucleus (STN-DBS) in a patient with DR-JME. We describe the treatment of a patient with DR-JME using STN-DBS. The patient underwent implantation and received high-frequency stimulation (HFS) at the STN. One year post-implantation, the patient demonstrated a substantial reduction in motor seizure frequency by 87.5%, with improvements in quality of life and seizure severity by 52.0% and 46.7%, respectively. No adverse events were reported during the follow-up period. This case represents the first report of favorable outcomes with STN-DBS in a patient with DR-JME, suggesting that long-term HFS of the STN may be a promising treatment option for patients suffering from this condition.

Designing a model predictive controller for graphite baking process

Model predictive controller provides better control quality for graphite products baking process than PID and its variations. The drawback of MPC is its high sensitivity to object modelling errors. If all of object parameters are varied just by 3 % simultaneously then MPC provides satisfactory control no more. In the current paper we design an adaptive MPC for baking process control. In order to identify furnace section “under the fire” on-line, we utilize recursive least squares algorithm with forgetting factor equal to 0,98. We compare conventional and adaptive MPCs in the following cases: accurate model; undesirable deviations of object parameters from model parameters (object is time invariant); desirable deviations; time variant object with step-changing parameters. In each case adaptive MPC provides control that ensures temperature difference inside the hottest (the most “dangerous”) graphite bar to be small enough, and even gives some margin for it (0,8 % to 8 %). However, the cost for this is increased process duration (4,8 % to 142,1 %) and more fuel-consuming (1,2 % to 106,2 %) than in case of non-adaptive MPC, even if the latter provides satisfactory control as well. In general, it is reasonable to use an adaptive MPC instead of a conventional one. Margin of economical reasonability needs further research. Also, it is necessary to compare different identification methods in order to achieve faster transition process.

On the Feasibility of a RGA-Based Decoupling Control in the Reactor-Follow-Turbine Operation of a PWR

Closed-loop control of the reactor-follow-turbine operation is attempted in this work. The reactor power is intended to follow the turbine load demand, whereas the coolant average temperature is to be maintained constant for reasons of design safety. To this effect, a standardized pressurized water reactor model is adopted wherein the reactor external reactivity and the feedwater mass flux are deemed the manipulated control signals. Offline system identification is carried out on the model input/output (I/O) terminals to extract first order plus time delay models thereof. A further relative gain array analysis is conducted to determine the most tightly coupled I/O channels. A proportional integral controller is thereafter designed for each channel, making use of an analytical gain/phase margin tuning mechanism. The results for different output tracking scenarios confirm a feasible and quite satisfactory closed-loop control practice.