Summary
In view of the result and performance of control are affected by the existence of input constraints and requirements, adaptive multi‐dimensional Taylor network (MTN) funnel control problem is ...studied for a class of nonlinear systems with asymmetric input saturation in this paper. Firstly, the effect of asymmetric input saturation can overcome by introducing the Gaussian error function, namely, the asymmetric saturation model is represented as a simple linear model with a bounded disturbance. Secondly, MTNs are employed to approximate the unknown functions in the controller design. Then, an adaptive MTN tracking controller is developed by blends the idea of funnel control into backstepping, which can guarantee that the tracking error always meets the given prescribed performance regarding the transient and steady state responses as well as the output of system tracks the give continuous reference signal. Finally, the effectiveness of the proposed control is demonstrated using two examples.
This study aimed to assess the effects of restricting mobile phone use before bedtime on sleep, pre-sleep arousal, mood, and working memory.
Thirty-eight participants were randomized to either an ...intervention group (n = 19), where members were instructed to avoid using their mobile phone 30 minutes before bedtime, or a control group (n = 19), where the participants were given no such instructions. Sleep habit, sleep quality, pre-sleep arousal and mood were measured using the sleep diary, the Pittsburgh sleep quality index, the Pre-sleep Arousal Scale and the Positive and Negative Affect Schedule respectively. Working memory was tested by using the 0-,1-,2-back task (n-back task).
Restricting mobile phone use before bedtime for four weeks was effective in reducing sleep latency, increasing sleep duration, improving sleep quality, reducing pre-sleep arousal, and improving positive affect and working memory.
Restricting mobile phone use close to bedtime reduced sleep latency and pre-sleep arousal and increased sleep duration and working memory. This simple change to moderate usage was recommended to individuals with sleep disturbances.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Effect of tea polyphenols (TP) on the quality of Chinese steamed bun (CSB) was investigated, while the interaction and action mechanism between TP and vital wheat gluten (VWG, constitutive proteins ...of flour) were further explored. With a low concentration (1%) of TP, CSB showed positive changes in quality, and the hardness of CSB decreased by 33.95%, while its specific volume, springiness, and resilience separately increased by 1.8%, 11.9%, and 5.5%, whereas the higher concentrations of TP (2% and 4%) caused an adverse impact. By observation of scanning electron microscope, VWG formed a fluffier structure with a low concentration of TP, while the structure deteriorated at high concentration of TP. In addition, the secondary and tertiary structures of VWG were both changed by TP. Along with the results of thermodynamic analysis (thermogravimetric and differential scanning calorimetry measurements), TP could induce the structural rearrangement of VWG. Further, a lower amidogen and sulfhydryl contents of VWG were obtained in TP groups, which illustrated that peptide and disulfide bonds of VWG were not possibly interrupted by TP. Instead, hydrophobic residues of VWG were bonded to form a more hydrophilic structure. Moreover, according to molecular docking results, epigallocatechin‐3‐gallate interacted tightly with VWG by hydrogen bonds and hydrophobic actions, and the action sites were mainly at hydrophobic and hydrophilic residues. All results suggested that the VWG structure was affected greatly by TP, and a low dose of TP might be potential to improve the quality of flour products.
Practical Application
The physicochemical properties of gluten show the significant effects on the quality of flour products in food industry. In the present study, a low dose of tea polyphenols exhibited a strengthened effect on gluten, so as to ameliorate the texture of Chinese steamed bun (CSB) due to their tight interactions with gluten, while the color of CSB was changed to brown as tea polyphenols. All results suggested that a low dose of tea polyphenols could be potentially utilized to improve flour quality and enhance gluten strength in food industry.
Secondary metabolites that have the same biological origin must share some relationship in their biosynthesis. Exploring this relationship has always been a significant task for synthetic biologists. ...However, from the perspective of synthetic chemists, it is equally important to propose, prove, or refute potential biosynthetic pathways in order to elucidate and understand the biosynthesis of homologous secondary metabolites. In this study, driven by the high structural similarity between the homologous Ganoderma meroterpenoids cochlearol B and ganocin B, two chemically synthetic strategies were designed and investigated sequentially for the synthesis of cochlearol B from ganocin B. These strategies include intramolecular metal‐catalyzed hydrogen atom transfer (MHAT) and intramolecular photochemical 2+2 cycloaddition. The aim was to reveal their potential biosynthetic conversion relationship using chemical synthesis methods. As a result, a highly efficient total synthesis of cochlearol B, cochlearol T, cochlearol F, as well as the formal total synthesis of ganocins A–B, and ganocochlearins C–D, has been achieved. Additionally, a novel synthetic approach for the synthesis of 6,6‐disubstituted 6H‐dibenzob,dpyran and its analogues has been developed through palladium(II)‐catalyzed Wacker‐type/cross‐coupling cascade reactions.
In this study, driven by the high structural similarity between the homologous Ganoderma meroterpenoids cochlearol B and ganocin B, two chemically synthetic strategies were designed and investigated sequentially for the synthesis of cochlearol B from ganocin B. These strategies include intramolecular metal‐catalyzed hydrogen atom transfer (MHAT) and intramolecular photochemical 2+2 cycloaddition. The aim was to reveal their potential biosynthetic conversion relationship using chemical synthesis methods. As a result, a highly efficient total synthesis of cochlearol B, cochlearol T, cochlearol F, as well as the formal total synthesis of ganocins A–B, and ganocochlearins C–D, has been achieved. Additionally, a novel synthetic approach for the synthesis of 6,6‐disubstituted 6H‐dibenzob,dpyran and its analogues has been developed through palladium(II)‐catalyzed Wacker‐type/cross‐coupling cascade reactions.
In this paper, the control issue of adaptive fault-tolerant is studied for a class of stochastic nonlinear systems with multiple faults and full state constraints, with multiple faults including the ...actuator faults and the external system fault. The problem with full state constraints are solved by constructing a logarithmic barrier Lyapunov functions (BLFs). By integrating multi-dimensional Taylor network (MTN) technology into the backstepping process, a new adaptive MTN-based fault-tolerant controller is designed. On the basis of considering multiple faults, the proposed control strategy can ensure that all signals in the closed-loop system are semi-global ultimately uniformly bounded (SGUUB) in probability, and all states of the system are constrained within the given boundary. Finally, three simulation examples are given to illustrate the effectiveness and practicability of the proposed control strategy.
For the tracking control problem of a class of switched nonlinear systems with input delay, this article proposes an adaptive tracking control scheme based on multi‐dimensional Taylor network (MTN) ...approach. First, Padé approximation and Laplace transform are employed to overcome the problem of input delay, and a new variable is introduced. Second, the MTNs are used to approximate the uncertain nonlinear structures in the process of controller design via backstepping. The results show that the controller designed in this article can keep all the signals in the closed‐loop system are bounded, meanwhile, the output tracking error can be converged to arbitrarily small. It should be pointed out that MTN‐based approach is applied to switched nonlinear systems subject to input delay for the first time. Finally, three examples are presented to verify the effectiveness of the proposed control strategy.
For switched nonlinear systems with output hysteresis, by working on multi-dimensional Taylor network (MTN), an adaptive control strategy is put forward, which can effectively solve the tracking ...control problem. Firstly, the modified Bouc-Wen hysteresis model is employed to cope with the nonlinear problem caused by output hysteresis. Secondly, the Nussbaum function is introduced into the control design process, and MTN is used to approach nonlinear structures. Thirdly, a novel network adaptive control strategy is constructed with the help of a common Lyapunov function, which can realize the tracking control and stability of the system simultaneously. It is worth noting that as a new type of neural network, MTN is first used for control of switched systems with output hysteresis. Finally, two simulation examples show that the proposed control strategy is effective.
For large‐scale switched nonlinear systems subject to asymmetric input saturation and output hysteresis, an adaptive control strategy is put forward by using a novel neural network, that is, ...multi‐dimensional Taylor network (MTN), which can effectively cope with the output tracking problem of this system. Firstly, asymmetric input saturation is expressed as the combination of a linear function and a bounded error function. Then, the modified Bouc‐Wen hysteresis model is employed to solve the nonlinear problem caused by output hysteresis. Afterwards, based on the approximation ability of MTN, a novel adaptive decentralized control method is designed by combining Lyapunov stability theory with adaptive backstepping technology, which realizes the stability and boundedness of the controlled systems. It should be noted that the asymmetric input saturation, the output hysteresis, large‐scale nonlinear systems and switched nonlinear systems appear in the same framework for the first time. Finally, a practical example and a numerical example are given to verify the availability of the proposed control strategy.
This paper concerns on the control problem of a class of nonlinear systems with input delay and dynamic uncertainties using multi-dimensional Taylor Network (MTN) control method. Firstly, a new ...variable is introduced to eliminate the effect of input delay by combining Padé approximation with Laplace transformation. Secondly, a MTN-backstepping-based control strategy is constructively designed by introducing a new coordinate transformation, and the proposed controller has the advantages of simple structure and good real-time performance. Finally, the effectiveness of the proposed MTN-based control approach is demonstrated by three examples.
In this paper, the full state constraints and input delay of stochastic nonlinear systems are studied. A new adaptive control algorithm is proposed using backstepping approach and multi-dimensional ...Taylor network (MTN) method. Firstly, the input delay problem is dealt with by introducing a new variable using the Padé approximation with Laplace transform. Secondly, MTNs are employed to approximate unknown nonlinear functions, and the barrier Lyapunov functions (BLFs) are constructed to deal with the state constraints. Based on this, a new approximation-based adaptive controller is proposed. Thirdly, it is proved that the proposed control method can ensure that all signals in the closed-loop system are semi-global ultimately uniformly bounded (SGUUB) in probability and the tracking error converges to a small neighborhood of the origin. Finally, two simulation examples are given to illustrate the effectiveness of the proposed design method.
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