This paper introduces a dual input–output parameterization (dual IOP) for the identification of linear time-invariant systems from closed-loop data. It draws inspiration from the recent input–output ...parameterization developed to synthesize a stabilizing controller. The controller is parameterized in terms of closed-loop transfer functions, from the external disturbances to the input and output of the system, constrained to lie in a given subspace. Analogously, the dual IOP method parameterizes the unknown plant with analogous closed-loop transfer functions, also referred to as dual parameters. In this case, these closed-loop transfer functions are constrained to lie in an affine subspace guaranteeing that the identified plant is stabilized by the known controller. Compared with existing closed-loop identification techniques guaranteeing closed-loop stability, such as the dual Youla parameterization, the dual IOP requires neither a doubly-coprime factorization of the controller nor a nominal plant that is stabilized by the controller. The dual IOP does not depend on the order and the state-space realization of the controller either, as in the dual system-level parameterization. Simulation shows that the dual IOP outperforms the existing benchmark methods.
•The proposed identification technique uses closed-loop input and output data.•The identification scheme is based on closed-loop transfer functions.•These transfer functions are referred to an dual input-output parameters.•The identified system model is guaranteed to be stabilized by the controller.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The immunosuppression and immune escape of current immunotherapy result in low efficacy, and ferroptosis is greatly restricted by the low reactive oxygen species (ROS) production efficiency. Here, ...for the first time a “closed‐loop” therapy based on photothermal enhancement of ferroptosis and immunotherapy stimulated by each other on a multifunctional nanoplatform is reported. This platform is composed of copper silicate and iron silicate mesoporous hollow nanospheres, followed by in situ growth of Au nanoparticles and loading of an immune adjuvant resiquimod R848. The laser irradiation‐mediated heat and the introduction of copper ions significantly enhance ROS generation, leading to the simultaneous depletion of glutathione peroxidase 4 (GPX4) and glutathione (GSH). The onset of ferroptosis in tumor cells is thus enhanced and an immune response with immunogenic cell death (ICD) is triggered, promoting the dendritic cells (DCs) maturation and T cell infiltration. Interferon γ (IFN‐γ) released from CD8+ T cells downregulates the expression of SLC7A11 and GPX4, which in turn enhances ferroptosis expression, thus constituting a “closed‐Loop” therapy. Importantly, this system is effective in both killing the primary tumor and inhibiting tumor metastasis. The proposed “closed‐loop” therapeutic strategy may provide a guidance for the design of future antitumor nanoplatforms.
A “closed‐loop” therapy is proposed based on mutually reinforced ferroptosis and immunotherapy on a multifunctional nanoplatform (CISAR). The enhanced reactive oxygen species generation and consumed GPX4 induce obvious ferroptosis. The body has a strong immune response with immunogenic cell death, resulting in T cells infiltration. IFN‐γ downregulates SLC7A11 and GPX4 expression, which in turn reinforce ferroptosis expression.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
With a good balance between power transfer distance and efficiency, wireless power transfer (WPT) using magnetic resonant coupling is preferred in many applications. Generally, WPT systems are ...desired to provide constant output voltage with the highest possible efficiency as power supplies. However, the highest efficiency is not achieved by the reported closed-loop WPT systems that maintain constant output voltage against coupling and load variations. In this paper, an efficiency evaluation method is put forward to evaluate the closed-loop control schemes. Furthermore, a maximum efficiency point tracking control scheme is proposed to maximize the system efficiency while regulating the output voltage. This control scheme is unique and prominent in that it fixes the operating frequency at the receiving-side resonant frequency and converts both the input voltage and the load resistance at the same time. Thus, the maximum efficiency point on the constant output voltage trajectory can be tracked dynamically. Therefore the system's output voltage can be maintained constant and its efficiency is always the highest. The experimental results show that the maximum efficiency point is tracked and a very high overall efficiency is achieved over wide ranges of coupling coefficient and load resistance.
A closed‐loop system that can mini‐invasively track blood glucose and intelligently treat diabetes is in great demand for modern medicine, yet it remains challenging to realize. Microneedles ...technologies have recently emerged as powerful tools for transdermal applications with inherent painlessness and biosafety. In this work, for the first time to the authors' knowledge, a fully integrated wearable closed‐loop system (IWCS) based on mini‐invasive microneedle platform is developed for in situ diabetic sensing and treatment. The IWCS consists of three connected modules: 1) a mesoporous microneedle‐reverse iontophoretic glucose sensor; 2) a flexible printed circuit board as integrated and control; and 3) a microneedle‐iontophoretic insulin delivery component. As the key component, mesoporous microneedles enable the painless penetration of stratum corneum, implementing subcutaneous substance exchange. The coupling with iontophoresis significantly enhances glucose extraction and insulin delivery and enables electrical control. This IWCS is demonstrated to accurately monitor glucose fluctuations, and responsively deliver insulin to regulate hyperglycemia in diabetic rat model. The painless microneedles and wearable design endows this IWCS as a highly promising platform to improve the therapies of diabetic patients.
A fully integrated wearable closed‐loop system (IWCS) based on microneedle‐iontophoresis platform is developed for in situ diabetic sensing and treatment. This IWCS is demonstrated to accurately monitor glucose fluctuations and responsively deliver insulin to regulate hyperglycemia. The painless microneedles and wearable design endow this IWCS as a highly promising platform to improve the therapies of diabetic patients.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The state-space approaches have stayed in an absolutely dominant position in the field of systems and control for over a half century. Although a state-space representation is more suitable for ...deriving the state-response solution and observation (estimation), it does not provide as much convenience as desired for the control problem. In this paper, the concept of high-order fully actuated (HOFA) systems is firstly revisited, and it is pointed out that HOFA systems serve really as models for control systems rather than representing a small portion of physical control systems. Based on the HOFA model, a basic procedure is proposed for control of nonlinear systems satisfying certain conditions, whose first step converts the nonlinear systems into a pseudo strict-feedback system, and the second step establishes the HOFA model of the system. Once an HOFA model is derived, a controller can be immediately designed to make the closed-loop system a constant linear one with a desired eigenstructure. All the design degrees of freedom existing in the closed-loop system are also provided, which can be further utilised to achieve additional system performance. An example demonstrates the design procedure and shows the effect of the proposed HOFA approach.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
This studies an adaptive control problem of pure-feedback non-linear systems with full state constraints. The mean value theorem is employed to deal with unknown non-linearities. A novel backstepping ...design is constructed via barrier Lyapunov function (BLF) combined with dynamic surface control (DSC). The BLF guarantees the full state constraints are not violated and all the closed-loop signals remain bounded. DSC solves the problems of restrictions on high order differentiability of stabilising functions and avoiding the complexity that arises due to the explosion of terms in backstepping design. It is shown that all the signals in the closed-loop system are ultimately bounded and the tracking error converges to an adjustable neighbourhood of the origin while the full state constraints remain unchanged. The performance of the BLF-based DSC is illustrated with two simulation examples.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Development of closed‐loop chemically recyclable plastics (CCRPs) that can be widely used in daily life can be a fundamental solution to the global plastic waste crisis. Hence, it is of great ...significance to develop easy‐to‐recycle CCRPs that possess superior or comparable material properties to the commodity plastics. Here, a novel dual crosslinked CCRP, namely, supramolecular covalent adaptable networks (supra‐CANs), is reported, which not only displays mechanical properties higher than the strong and tough commodity polycarbonate, but also exhibits excellent solvent resistance as thermosets. The supra‐CANs are constructed by introducing reversible noncovalent crosslinks into the dynamic covalent polymer networks, resulting in highly stiff and strong thermosets that also exhibit thermoplastic‐like ductile and tough behaviors as well as reprocessability and rehealability. In great contrast, the analogs that do not have noncovalent crosslinks (CANs) show elastomeric properties with significantly decreased mechanical strength. Importantly, the developed supra‐CANs and CANs can be converted back into the initial monomers in high yields and purity at room temperature, even with additives, which enables the sustainable polymer‐monomer‐polymer circulation. This work provides new design principles for high‐performance chemically recyclable polymers as sustainable substitutes for the conventional plastics.
Supramolecular covalent adaptable networks (supra‐CANs) with room‐temperature closed‐loop recyclability are constructed by introducing reversible noncovalent crosslinks into the dynamic covalent polymer networks, resulting in strong and stiff thermosets that also exhibit thermoplastic‐like ductility and toughness, as well as reprocessability and rehealability. The mechanical properties of the supra‐CANs are superior to those of strong and tough commodity polycarbonate.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This paper puts forward the Circular Strategies Scanner: a framework that introduces a taxonomy of circular strategies developed for use by manufacturing companies engaging in circular economy (CE) ...oriented innovation. Currently, a range of frameworks exists that propose a vision for how to operate in a CE, by identifying and organising relevant circular strategies. However, these frameworks have a limited applicability for specific business types, in particular manufacturing, and are unsuitable for use in CE oriented innovation, due to a lacking ability to support innovation processes through: 1) creating a comprehensive understanding of circular strategies, 2) mapping strategies currently applied and 3) finding opportunities for improved circularity across a range of business processes. This paper addresses these shortcomings by proposing a circular strategies framework for the manufacturing context, titled the Circular Strategies Scanner, which provides a comprehensive set of definitions of circular strategies and directly supports the early stages of CE oriented innovation. With this, the paper contributes to the body of work that develops CE transition methodology.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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