Journals
2026 EN
Dang HaoHung · Blitz Sandra · Bansback Nick
+2 more
Objective This study aimed to evaluate the impact of a series of policies that mandated switching patients with inflammatory arthritis (IA) from an originator biologic to a biosimilar in British Columbia, Canada, on health care resource use and cost. Methods The health data of patients with IA were obtained from five linked administrative databases held by Population Data BC from January 2013 to December 2022. Our analysis focused on trends in monthly average use and costs of four care resources: physician services, hospital services, emergency department visits, and concomitant drug use. Using interrupted time series analysis, we evaluated the impact of switching policies targeting (1) infliximab or etanercept and (2) adalimumab on total health care costs, excluding biologic and biosimilar costs. Results We included 3,150 patients in the study. Hospital and physician services accounted for the majority of the total care cost for patients with IA. We found no evidence of any increases in physician services, hospital services, emergency department visits, or concomitant drug use after either nonmedical switch policy. We also found no significant change in level and trend in total health care costs for both policies: infliximab or etanercept (level −$40, 95% confidence interval [CI] −$99 to $19; trend $5.42, 95% CI −$0.62 to $11.46) and adalimumab (level −$34, 95% CI −$139 to $70; trend −$8.97, −$17.94 to $0.00). Conclusion Nonmedical biosimilar switching policies did not lead to increases in other health care service use and costs.
Journals
2026 EN
Hao Yanjie · Hansen Dylan · KandaneRathnayake Rangi
+36 more
Objective This study aimed to identify in patients with systemic lupus erythematosus (SLE) with clinically active disease the attainment of frequency and determinants of Lupus Low Disease Activity State (LLDAS) and Definition of Remission in SLE (DORIS) and the frequency and determinants of flare and damage accrual after target attainment. Methods Patients in a multinational cohort with SLE who had clinical disease activity but were not in LLDAS or DORIS were observed prospectively. Results A total of 1,991 patients (93.2% female) were observed for a median (interquartile range) of 2.5 (0.7–4.5) years, with 70.9% and 55.6% achieving LLDAS and DORIS, respectively. Nephritis and low complements were associated with a longer time, and antimalarial and immunosuppressant use were associated with a shorter time to LLDAS attainment. After the first LLDAS and DORIS attainment, 47.0% and 47.5% of the patients experienced flare(s), respectively, and 9.5% and 7.9 % of patients accrued organ damage within 24 months, respectively. Longer cumulative time at target and antimalarial use was associated with a longer time to flare and damage accrual, whereas dose reduction in glucocorticoids and immunosuppressants was associated with a shorter time to flare. Reduction in immunosuppressants also correlated with a shorter time to damage accrual. Conclusion In patients with SLE with clinical disease activity, the proportion attaining LLDAS and DORIS under usual care conditions is suboptimal. Longer maintenance of these states is significantly associated with reduced risk of flare. Because flares and damage accrual still occur frequently following initial target attainment, further research is needed to inform strategies for maintaining these targets.
Journals
2026 EN
Liu Yekun · Zhang Xiaoyu · Tan Panlong
ABSTRACT This study focuses on the terminal angle constrained interception of maneuvering target by missile in three‐dimensional (3D) coupled environment. Considering actuator failures and input saturation, an adaptive non‐singular terminal sliding mode guidance law is proposed based on the predefined‐time convergence theory. Its design features an adjustable convergence time parameter. First, an adaptive guidance law is developed, the states can converge to zero in the predefined time under ideal conditions. Subsequently, based on this foundation, another anti‐saturation fault‐tolerant guidance law is developed, which can realize the interception of targets in scenarios involving actuator failure and input saturation. Comprehensive simulation experiments validate the efficacy of the proposed algorithms.
Journals
2026 EN
Zhou Yuxing · Hao LiYing · Wang RunZhi
+1 more
ABSTRACT The resilience and robustness of model predictive control are typically contingent upon an adequately extended prediction horizon, yet it is constrained in real‐time applications by limited computational resources. To tackle this issue, this paper introduces a finite‐time Lyapunov‐based model predictive control (FTLMPC) approach, independent of the prediction horizon, for unmanned surface vehicles (USVs) subject to external disturbances and denial‐of‐service (DoS) attacks. Firstly, a finite‐time auxiliary control system is integrated within the FTLMPC framework. This system incorporates a finite‐time extended state observer (FTESO) for precise disturbance estimation and a finite‐time backstepping control law to guarantee zero tracking errors. Consequently, FTLMPC ensures finite‐time stability during each DoS attack interval, effectively preventing error accumulation despite the presence of disturbances and DoS attacks. Secondly, a novel compensation scheme is introduced to mitigate the information loss induced by DoS attacks, wherein the compensation signal is solely derived from the control signal at the moment of the last successful transmission, thus minimizing reliance on the prediction horizon. It enables flexible adaptation of the prediction horizon and control performance according to the available computational resources. Finally, the simulation results validate the superior control performance of the proposed strategy.
Journals
2026 EN
Lan YongHong · Yuan YuKe · Wu JinYi
+1 more
ABSTRACT This paper proposes an integral sliding mode control (ISMC) method based on preview repetitive control (PRC) for continuous‐time nonlinear systems with the presence of matched uncertainties, external disturbances, and norm‐bounded nonlinearities. First, a two‐dimensional (2D) dynamic system is constructed. Second, the linear matrix inequality (LMI)‐based condition is proposed, and the PRC law is designed for the nominal system. Then, a preview repetitive integral sliding mode control (PRISMC) law is obtained by combining an integral sliding mode controller with the preview repetitive controller, which ensures the robustness of the linear system. Finally, the effectiveness of the method is verified by a numerical simulation.
Journals
2026 EN
Liu Shuo · Zhang Huaguang · Pang Hongbo
ABSTRACT This paper investigates adaptive finite‐time quasi‐passification and finite‐time stabilization problems for uncertain switched nonlinear systems with parameter uncertainties. Finite‐time quasipassivity concept of a switched nonlinear system is first proposed. For each active subsystem, finite‐time quasi‐passivity is satisfied, while at every switching time, the energy is allowed to increase. Compared with passive systems, the supply rate of a quasi‐passive system includes a passivity supply rate and a constant supply rate. Based on this concept, a more general state‐dependent switching law and singularity‐free adaptive feedback controllers are given to achieve finite‐time quasi‐passification, even if the subsystem is not feedback finite‐time quasi‐passive. Then, the corresponding finite‐time quasi‐passivity‐based adaptive stabilization is studied. Finally, a practical example is presented to illustrate the effectiveness of our method.
Journals
2026 EN
Zhang Hao · Zhang Liang · Zhao Ning
+3 more
ABSTRACT This paper investigates the event‐triggeredl 2 − l ∞$$ {l}_2-{l}_ filtering problem for discrete‐time switched systems subject to denial‐of‐service attacks. To address the mismatch between the filter modes and the system modes induced by the event‐triggered strategy, the mode‐dependent average dwell time switching law is introduced to guarantee the global uniform exponential stability of the switched filtering error system with thel 2 − l ∞$$ {l}_2-{l}_ performance. Unlike traditional average dwell time, which relies on a fixed dwell time threshold, mode‐dependent average dwell time dynamically assigns mode‐dependent dwell time thresholds, significantly improving flexibility in stability analysis and filter design during asynchronous intervals. Furthermore, collaborative design methods for the filter and event‐triggered parameters under denial‐of‐service attacks are provided. Finally, the feasibility and applicability of the proposed approach are demonstrated through a numerical example and the model of a boost converter controlled by pulse‐width modulation.
Journals
2026 EN
Uzoeto Ignatius Ifeanyi · Gao Guoqin
ABSTRACT In a hybrid robot mechanism, disturbances and significant payload variations with bounded torque inputs constitute a significant problem. In view of these uncertain dynamics, a new model‐free robust adaptive control is developed using: nonlinear proportional‐derivative ideal velocity feedback (NPD‐IVF); novel inertia‐gain adaptation control; and time‐delay control (TDC). The proposed control scheme has four components: a time‐delay estimation (TDE), a new NPD‐IVF desired error dynamics, an inertia‐gain adaptation law, and a saturation function (applied to guarantee torque input boundedness). The TDE component is used to get the lumped system dynamics thereby establishing a practical model‐free framework. The NPD‐IVF is designed to enhance the controller, reduce inherent estimation error and improve the position tracking performance. A gain‐adaptation law exploits a neuro‐fuzzy network that leads to a real‐time dynamic update of the inertia gain matrix; this tolerates significant variations in payload and disturbances. Cumulative effects of these four components result in the proposed control being input torque bounded, model‐free, improved accuracy and robust. Experimental comparisons were made using a prototype hybrid mechanism for vehicle electro‐coating conveying with various payload conditions to verify the effectiveness of the proposed control.
Journals
2026 EN
Tao Xinyue · Tao Hongfeng · Gao Luyuan
+2 more
ABSTRACT This paper develops a predictive optimal iterative learning control design for nonlinear systems based on the Koopman operator. Iterative learning control applies to systems that undergo repeated executions, known as trials, over a finite duration, the trial length. Once a trial is complete, all information generated is available to update the control signal for the subsequent trial. The first step in design is to approximately model the nonlinear system as a high‐dimensional linear model using the Koopman operator and extended dynamic mode decomposition, which is applied on each trial. Then, an iterative learning control law is designed with predictive action over an infinite duration in the trial‐to‐trial direction. The robust convergence of the tracking error is analyzed, and a numerical case study demonstrates the effectiveness of the design.
Journals
2026 EN
Sun Kangkang · Liang Zhiheng · Zheng Qi
ABSTRACT This article considers the secure adaptive trajectory tracking control problem for spacecraft attitude systems with unknown false data injection (FDI) attacks and disturbance. The kinematics and dynamics equations of a 3‐1‐2 rotation sequence using Euler angles are given to construct a model of the spacecraft attitude systems. A recursive scheme is developed to design virtual and actual control laws. Meanwhile, a parameter adaptive law is utilized to estimate the upper bound of the attack signal. The proposed control method can guarantee that the tracking error of attitude angles converges to a small region of the origin, and a Lyapunov function is utilized to prove the stability of the spacecraft attitude closed‐loop systems. Finally, simulation results are provided to verify the effectiveness of the developed approach.