This paper presents an adaptive fuzzy control approach for a category of uncertain nonstrict-feedback systems with input saturation and output constraint. A variable separation approach is introduced ...to overcome the difficulty arising from the nonstrict-feedback structure. The problem of input saturation is solved by introducing an auxiliary design system, and output constraint is handled by utilizing a barrier Lyapunov function. Combing fuzzy logic system with the adaptive backstepping technique, the semi-global boundedness of all variables in the closed-loop systems is guaranteed, and the tracking error is driven to the origin with a small neighborhood. The stability of the closed-loop systems is proved, and the simulation results reveal the effectiveness of the proposed approach.
Targeted saturation mutagenesis of crop genes could be applied to produce genetic variants with improved agronomic performance. However, tools for directed evolution of plant genes, such as ...error-prone PCR or DNA shuffling, are limited
. We engineered five saturated targeted endogenous mutagenesis editors (STEMEs) that can generate de novo mutations and facilitate directed evolution of plant genes. In rice protoplasts, STEME-1 edited cytosine and adenine at the same target site with C > T efficiency up to 61.61% and simultaneous C > T and A > G efficiency up to 15.10%. STEME-NG, which incorporates the nickase Cas9-NG protospacer-adjacent motif variant, was used with 20 individual single guide RNAs in rice protoplasts to produce near-saturated mutagenesis (73.21%) for a 56-amino-acid portion of the rice acetyl-coenzyme A carboxylase (OsACC). We also applied STEME-1 and STEME-NG for directed evolution of the OsACC gene in rice and obtained herbicide resistance mutations. This set of two STEMEs will accelerate trait development and should work in any plants amenable to CRISPR-based editing.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper focuses on the H ∞ fault detection (FD) problem for spring-mass systems (SMSs) over networks with distributed state delays, random packet losses, sensor saturation as well as ...multiplicative noises via unreliable communication channels. The output measurements are affected by sensor saturation which is described by sector-nonlinearities. The multiplicative noises are described as a form of Gaussian white noises multiplied by the states. A series of stochastic variables are introduced to describe the randomly occurring distributed state delays. Random packet losses are also introduced in unreliable communications. The purpose of this paper is to design an FD filter such that: 1) The FD dynamic system is exponentially stable in the mean square. 2) The error between the fault signal and the residual signal is controlled to the minimum. 3) The optimal H ∞ filtering performance index is achieved. A sufficient condition for the FD filter design is derived in terms of the solution to a linear matrix inequality (LMI). When the LMI has a feasible solution, the explicit parameters of the desired FD filter can be obtained. Finally, a simulation experiment is illustrated to show the effectiveness and application of the designed method.
The aims of this article are to:•Recognise the role of accurate oxygen saturation readings in guiding oxygen therapy.•Identify the limitations of the use of pulse oximetry in measuring oxygen ...saturation.•Understand the basic principles of the mechanism by which pulse oximeters obtain saturation readings.•Have an understanding of the studies investigating the degree of bias of skin colour on pulse oximetry readings.•Interpret pulse oximetry readings in the clinical setting with the knowledge that readings may be less reliable in patients with pigmented skin.
Pulse oximetry is widely used to non-invasively estimate the oxygen saturation of haemoglobin in arterial blood (SpO2). It is used widely throughout healthcare and was used extensively during the Covid-19 pandemic to detect and treat hypoxic patients. Research has suggested that pulse oximetry is less accurate in patients with darker skin. This led the US Food and Drug Administration agency (FDA) to issue a safety statement warning that pulse oximeters may be inaccurate when patients have pigmented skin.
Evidence suggests that the oxygen saturation of arterial blood (SaO2) may be being overestimated by measuring SpO2 in those with pigmented skin. The degree of overestimation increases as SaO2 decreases especially when SpO2 reads below 80%. We review how pulse oximetry works and consider the implications for a patient’s health when interpreting SpO2 in individuals with pigmented skin.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This brief investigates the finite-time control problem associated with attitude stabilization of a rigid spacecraft subject to external disturbance, actuator faults, and input saturation. More ...specifically, a novel fixed-time sliding mode surface is developed, and the settling time of the defined surface is shown to be independent of the initial conditions of the system. Then, a finite-time controller is derived to guarantee that the closed-loop system is stable in the sense of the fixed-time concept. The actuator-magnitude constraints are rigorously enforced and the attitude of the rigid spacecraft converges to the equilibrium in a finite time even in the presence of external disturbances and actuator faults. Numerical simulations illustrate the spacecraft performance obtained using the proposed controller.
Bernard and Bray respond to comments from Wetsch and Bottiger on their study on the relationship betwee oxygen saturation targets and survival to hospital discharge among patients resuscitated after ...out-of-hospital cardiac arrest. Wetsch and Bottiger are concerned that a target oxygen saturation of 90% to 94% in the EXACT trial should be considered hypoxia. This target oxygen saturation was justified by a meta-analysis of previous phase 2 trials testing a lower oxygen target in patients with out-of-hospital cardiac arrest. In that meta-analysis, there was a range of different "low" oxygen targets.
Identifying the most influential spreaders is an important issue in controlling the spreading processes in complex networks. Centrality measures are used to rank node influence in a spreading ...dynamics. Here we propose a node influence measure based on the centrality of a node and its neighbors’ centrality, which we call the neighborhood centrality. By simulating the spreading processes in six real-world networks, we find that the neighborhood centrality greatly outperforms the basic centrality of a node such as the degree and coreness in ranking node influence and identifying the most influential spreaders. Interestingly, we discover a saturation effect in considering the neighborhood of a node, which is not the case of the larger the better. Specifically speaking, considering the 2-step neighborhood of nodes is a good choice that balances the cost and performance. If further step of neighborhood is taken into consideration, there is no obvious improvement and even decrease in the ranking performance. The saturation effect may be informative for studies that make use of the local structure of a node to determine its importance in the network.
•A centrality measure encoding the centrality of a node’s neighborhood is proposed.•The neighborhood centrality outperforms degree and coreness in ranking spreaders.•A saturation effect of the neighborhood is discovered.•Considering the 2-step neighborhood of a node balances the cost and performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
We investigated temporal changes in the rock-magnetic properties of volcanic ash ejected from the Aso Nakadake volcano during a sequence of ash eruptions from 2019 to 2020. For 39 volcanic ash ...samples, magnetic hysteresis parameters, including saturation magnetization (
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), saturation remanent magnetization (
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), coercivity (
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), and coercivity of remanence (
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), were obtained. Curie temperature (
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) of the samples was also estimated using thermomagnetic analyses. Titanium-rich and -poor titanomagnetites were the dominant magnetic minerals in the volcanic ash, of which the titanium-rich phase was dominant. Systematic magnetic measurements of the volcanic ash ejected during the 1-year eruption event indicate that temporal changes in the hysteresis parameters occurred throughout the event. These temporal changes suggest that the
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values of the volcanic ash increased considerably during several periods. The clear increases in
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and
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, associated with the central peak in FORC diagrams, indicate that non-interacting single-domain grains increased. For these high
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samples, thermal demagnetizations of 3-axis IRM show that the low unblocking-temperature component up to 250–300 °C has apparently higher coercivity, suggesting that the above-mentioned, non-interacting single-domain grains are Ti-rich titanomagnetite. Interestingly, the high
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values were synchronous with observations of volcanic glow. These results suggest that changes in the magnetic properties of titanomagnetite grains in volcanic ash reflect changes in physical conditions from the vent to the conduit of the volcano.
Graphical Abstract
In this article, the magnetic energy harvester (MEH) based on the current transformer is an innovative method to provide a potential solution for the power supply of sensor networks. Due to the ...current fluctuation and nonlinearity of the core, the harvester may produce insufficient power at low primary currents, while the core saturates at high primary currents. Aiming at resolving this problem, a novel method is proposed to improve the performance of MEH. In this method, a capacitor and two switches are used to store energy and modulate the core saturation. The performed analyses demonstrate that the proposed method enhances the harvested power under different primary current and load conditions. This is especially more pronounced at low primary currents and loads. It is found that for a low primary current of 2 A rms at 50 Hz, the harvested power increases by 206%. Moreover, applying this method can also reduce the load voltage by controlling the alternating on-off of the switches, thereby protecting the harvester in case of high primary currents. The theoretical calculation, circuit simulation, and experimental results demonstrate the effectiveness of this method.
Recently a new empirical model for the capillary pressure in porous media has been proposed (see Foroughi et al. in Transp Porous Media 145:683–696, 2022). In the present Note some of the ...mathematical features of this model are discussed in more detail. The focus is the lowest slope
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of the pressure–saturation curves
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=
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. In this respect an absolute minimum, as well as dual saturation-exponents have been detected.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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