The asynchronous finite-time dynamic output feedback control problem is concerned for switched time-delay systems with non-linear disturbances. By constructing multiple Lyapunov functions and ...resorting to the average dwell-time approach, an asynchronous dynamic output feedback controller is designed to ensure the finite-time stability of the resulting closed-loop system, where asynchronous means that there is a lag between switching of controllers and subsystems. It should be pointed out that the Lyapunov function energy is allowed to increase during the running intervals of the active subsystems. Furthermore, all the conditions are formulated in forms of a set of linear matrix inequalities which can be easily solved by using the recently developed interior point method. Finally, two examples are provided to show the potential of the main results.
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•Diverse thermal and mineral responses were unveiled.•Explored temperature's critical influence on Al extraction process efficiency.•Demonstrated eco-friendly Na2CO3 recovery boosts ...sustainability.•Innovatively integrated Na2CO3 as a carbon sink, contributing to sustainability.
This study proposes transforming red mud, an abundant byproduct from the aluminum industry, into minerals using Na2CO3 activation for efficient water leaching. It was aimed at breaking down the rigid Al-Si network structure. The investigation compares the effects of sodium salts, with Na2CO3 achieving an 88.90 % aluminum leaching rate crucial for activating katoite and cancrinite in red mud. Using XRD, FT-IR, SEM-EDS, in situ hot-stage microscopy, FactSage, and Material Flow Analysis, the study explores changes in Na2CO3-loaded red mud, elucidating its role in converting aluminum-bearing minerals into water-soluble aluminates at a low temperature of 900 °C for an optimum activation duration of 90 min, with a preferred loading of 32 % Na2CO3. Introducing a new cyclic aluminum extraction method from red mud, utilizing sodium salts, especially Na2CO3, the study optimizes the activation process through a comprehensive exploration of thermal and mineral transformation behaviors. Quantitative analysis of Na and Al elements ensures successful recovery and cyclic utilization of Na2CO3, maintaining aluminum extraction efficiency above 82 % after six cycles. This economically feasible closed-loop system aligns with principles of industrial efficiency and climate change mitigation. Na2CO3, acting as an activator and a carbon sink, showcases significant potential for sustainable aluminum production.
The aim of this study was to observe the 1-year clinical outcomes of people with type 1 diabetes who switched from multiple daily injection + blood glucose meter to an advanced hybrid closed-loop ...(AHCL) system (Medtronic MiniMed™ 780G system MM 780G). In addition, the effect of changing at month 6 to a calibration-free sensor (Guardian™ 4 Sensor G4S) was evaluated. Eighteen participants (10 men, age 40.9 ± 7.6 years) completed 1 year of MM 780G use. Time in range (TIR; 70-180 mg/dL) remained stable and ranged from 83.2% in month 9 to 84.8% in month 3. There was no difference between TIR at 3 months before switching versus 3 months after switching to G4S (
= 0.614). AHCL system in adults significantly improves glycemic outcomes. This improved glycemic control was maintained over the 12 months. Switching to a calibration-free sensor (G4S) did not affect outcomes but required less patient involvement.
This study proposes an adaptive approximation-based control approach for non-linear pure-feedback systems in the presence of full state constraints. Completely non-affine non-linear functions are ...considered and assumed to be unknown. The dynamic surface design based on integral barrier Lyapunov functionals is provided to achieve both the desired tracking performance and the constraints satisfaction, in consideration of the full-state-constrained non-affine non-linearities. In this design procedure, simple sufficient conditions for choosing control gains, which can be checked off-line, are established to guarantee the feasibility of the controller. The function approximation technique is employed to estimate unknown non-linearities induced from the controller design procedure where the adaptive laws using the projection operator are designed to ensure the boundedness of the function approximators in the feasibility conditions. It is shown that all the signals in the closed-loop system are uniformly ultimately bounded and the tracking error converges to an adjustable neighbourhood of the origin while all state variables always remain in the constrained state space.
Aim
To investigate glycaemic outcomes in youths and adults with type 1 diabetes with either MiniMed™ 780G or Tandem t:slim X2™ control‐IQ automated insulin delivery (AID) systems and to evaluate ...clinical factors that migrate, mitigate the achievement of therapeutic goals.
Materials and Methods
This retrospective, real‐world, observational study was conducted in a specialized university type 1 diabetes centre with patients observed for 3‐12 months post‐initiation of an AID system. Primary outcomes were the percentage time in the target glucose range TIR70‐180 mg/dl (3.9‐10 mmol/L) as measured by continuous glucose monitoring, mean glucose management indicator (GMI) and glycated haemoglobin (HbA1c) levels.
Results
Our study cohort consisted of 48 adolescents and 183 adults (55% females) aged 10‐77 years. The mean (95% confidence interval) TIR70‐180 mg/dl after 30 days was higher than baseline and by 14% points after 360 days with 71.33% (69.4‐73.2) (n = 123, p < .001). HbA1c levels decreased by 0.7% and GMI by 0.6% after 360 days. The proportion of time spent <70 mg/dl (3.9 mmol/L) was not significantly different from baseline. During follow‐up, 780G users had better continuous glucose monitoring results than control‐IQ users but similar HbA1c levels, and an increased risk of weight gain. Age at onset influenced TIR70‐180 mg/dl in univariate analysis but there was no significant relationship after adjusting on explanatory variables. Baseline body mass index did not influence the performance of AID systems.
Conclusions
This analysis showed the beneficial effects of two AID systems for people with type 1 diabetes across a broad spectrum of participant characteristics. Only half of the participants achieved international recommendations for glucose control with TIR70‐180 mg/dl >70%, HbA1c levels or GMI <7%, which outlines the need to maintain strong educational and individual strategies.
In modern power systems the smooth control of active power flow is one of the major concerns for power industry. In the current study the authors devise an adaptive fractional order robust damping ...control system for static series synchronous compensator connected to an infinite power transmission network. A detailed non‐linear state model is presented with inclusion of parametric uncertainties, disturbances and other non‐linearities. A novel fractional order sliding manifold is proposed and based on it an adaptive fractional order controller is derived. The uncertainty in the state model is estimated online using the adaptive control system. The stability and the convergence proof of the closed loop system is verified using fractional order Lyapunov theorem. Furthermore, the proposed control scheme is compared with the classical proportional integral derivative, integer order sliding mode and fractional order controllers under different scenarios. The effectiveness of the proposed control scheme is verified using numerical simulations.
This study investigates the non-fragile sampled-data guaranteed cost control problem for a bio-economic singular Markovian jump system that is represented by the Takagi–Sugeno fuzzy model. The main ...intention of this study is to design a non-fragile sampled-data controller for the considered model to handle the issue of tax fluctuations by means of showing that the closed-loop system is regular, impulse free and stochastically finite-time bounded. Sampled-data controller is the one where the continuous system is controlled by the digital control algorithms. By introducing a proper Lyapunov–Krasovskii functional and using linear matrix inequality (LMI) approach, a new set of criteria is obtained in terms of LMIs for achieving the required result. More precisely, by solving LMIs, an upper bound for the cost function can be obtained. Finally, a simulation result is given to illustrate the effectiveness of the proposed control design.
This study investigates a formation control problem of autonomous underwater vehicles (AUVs) with unknown control directions. By employing the Nussbaum gain technique to deal with the unknown control ...directions, a finite-time formation control approach is proposed. To deal with the so-called ‘explosion of complexity’ issue in backstepping control, a compensator-based command filter technique is introduced to realise the derivative of virtual control signals. With the proposed method, the formation can be achieved within a finite settling time and all signals in the closed-loop system are uniformly bounded. The effectiveness and performance is demonstrated by numerical simulations.
Advances in computer processing technology have enabled researchers to analyze real-time brain activity and build real-time closed-loop paradigms. In many fields, the effectiveness of these ...closed-loop protocols has proven to be better than that of the simple open-loop paradigms. Recently, sleep studies have attracted much attention as one possible application of closed-loop paradigms. To date, several studies that used closed-loop paradigms have been reported in the sleep-related literature and recommend a closed-loop feedback system to enhance specific brain activity during sleep, which leads to improvements in sleep's effects, such as memory consolidation. However, to the best of our knowledge, no report has reviewed and discussed the detailed technical issues that arise in designing sleep closed-loop paradigms. In this paper, we reviewed the most recent reports on sleep closed-loop paradigms and offered an in-depth discussion of some of their technical issues. We found 148 journal articles strongly related with 'sleep and stimulation' and reviewed 20 articles on closed-loop feedback sleep studies. We focused on human sleep studies conducting any modality of feedback stimulation. Then we introduced the main component of the closed-loop system and summarized several open-source libraries, which are widely used in closed-loop systems, with step-by-step guidelines for closed-loop system implementation for sleep. Further, we proposed future directions for sleep research with closed-loop feedback systems, which provide some insight into closed-loop feedback systems.
To evaluate the efficacy, safety and satisfaction of the closed-loop system Accu-Chek
Insight with Diabeloop™ (DBLG1™) in adults with type 1 diabetes (T1D) in real-world conditions.
Patients with T1D ...using DBLG1 for at least 3 months were included. Glucometric parameters were analyzed at baseline, 1, 2, and 3 months after starting DBLG1. HbA
was measured before and at 3 months. Technical issues and acute complications were recorded and patients completed a satisfaction questionnaire.
Sixty-two patients were included (43 women; age 44.2 ± 11 years; diabetes duration 24.6 ± 12 years; 40 used flash and 22 continuous glucose monitoring (CGM); 45 were on insulin pump and 17 on multiple daily injections). A significant improvement was observed in the CGM-derived glucose metrics early in the first month: Time in range (%TIR) 70-180 mg/dL (54.86 ± 17 vs. 72.23 ± 10.11); time above range level 1 (%TAR1) 180-250 mg/dL (26.26 ± 13.3 vs. 19.48 ± 6.78), time above range level 2 (%TAR2) > 250 mg/dL (12.02 ± 13.09 vs. 6.14 ± 5.23), time below range level 1 (%TBR 1) 54-70 mg/dL (5.73 ± 11.5 vs. 1.67 ± 1.3), time below range level 2 (%TBR2) < 54 mg/dL (1.18 ± 1.97 vs.0.44 ± 0.49), %CV (38.66 ± 7.53 vs. 29.63 ± 3.74), median glucose (168.57 ± 36 mg/dL vs. 154.63 ± 17.55 mg/dL), and %GMI (7.37 ± 0.91 vs. 7.02 ± 0.42). Also, HbA
decreased significantly (7.45% ± 1.05% vs. 6.95% ± 0.7%). No acute complications or serious adverse events occurred. Similar improvement was observed regardless of prior therapy or the glucose monitoring system used. Three patients discontinued DBLG1 and 21 experienced technical issues. Overall, patient satisfaction was high. Adjustments of the settings were modified in general in the direction of greater aggressiveness.
A significant improvement in glycemic control without serious adverse events and a high degree of patient satisfaction were observed in this first real-world study evaluating the closed-loop system, Accu-Chek Insight with Diabeloop.
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