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The failure rates of phase 3 trials are high. Incorrect sample size due to uncertainty of effect size could be a critical contributing factor. Adaptive sequential design (ASD), which may include one or more sample size re-estimations (SSR), has been a popular approach for dealing with such uncertainties. The operating characteristics (OCs) of ASD, including the unconditional power and mean sample size, can be substantially affected by many factors, including the planned sample size, the interim analysis schedule and choice of critical boundaries and rules for interim analysis. We propose a systematic, comprehensive strategy which uses iterative simulations to investigate the operating characteristics of adaptive designs and help achieve adequate unconditional power and cost-effective mean sample size if the effect size is in a pre-identified range. [ABSTRACT FROM AUTHOR]

In a fuel cell system, the performance of the ejector is limited when it operates under off-design conditions. To improve the performance of the ejector under all operating conditions in the fuel cell system, this study employs a multi-response optimization approach to optimize the structural parameters of the ejector. The optimization objectives are the entrainment ratio under low-power and high-power operating conditions, with the optimization variables including the mixing tube diameter (Dm), primary nozzle exit position (Lnxp), and mixing tube length (Lm). A quadratic polynomial model is proposed to correlate the key structural parameters of the ejector with the entrainment ratio using the response surface methodology based on the Box-Behnken design. The optimal structural parameters of the ejector are obtained using the desirability function approach. The results demonstrate that this optimization approach significantly improves the ejector performance under off-design conditions while the performance remains essentially unchanged under high-power operating conditions. [ABSTRACT FROM AUTHOR]

Single-arm phase II trials are very common in oncology. A fixed sample trial may lack sufficient power if the true efficacy is less than the assumed one. Adaptive designs have been proposed in the literature. We propose a Simon’s design based, adaptive sequential design. Simon’s design is the most used fixed sample design for single-arm phase II oncology trials. A prominent feature of Simon’s design is that it minimizes the sample size when there is no clinically meaningful efficacy. We identify Simon’s trial as a special group sequential design. Established methods for sample size re-estimation (SSR) can be readily applied to Simon’s design. Simulations show that simply adding SSR to Simon’s design may still not provide desirable power. We propose some expansions to Simon’s design. The expanded design with SSR can provide even more power. [ABSTRACT FROM AUTHOR]

This study presents a novel observer-based fuzzy control for chaotic systems (CSs). A class of CSs with unmeasurable states, unknown input constraints and unknown dynamics is taken to account. A generalised type-2 (GT2) fuzzy logic system (FLS) is formulated to approximate the uncertainties. The parameters of GT2-FLS are adjusted through the tuning rules that are extracted from robustness investigation. The proposed method is applied on CSs and it is demonstrated that the suggested observer and control system result in good performance in versus of disturbances, uncertainties, unknown and time-varying input nonlinearities, unmeasurable states and noisy faults. Comparison with other type of fuzzy systems demonstrates that the proposed GT2-FLS based controller is more effective. [ABSTRACT FROM AUTHOR]

To probe into the changes and significance of serum acetylcholine receptor antibody (AchR-Ab) and citric acid extractive antibody (CAE-Ab) in patients with thymoma after thoracoscopic surgery (TS). The data of 50 patients with thymoma receiving TS in our hospital from February 2017 to February 2021 were selected for retrospective analysis. Serological testing was performed before and after surgery to determine serum AchR-Ab and CAE-Ab levels, the therapeutic effect was evaluated and the trend of serum AchR-Ab and CAE-Ab changes and their meanings were analyzed. Among 50 patients with thymoma after TS, 15 (30.0%) were in remission, 25 (50.0%) had improvement and 10 (20.0%) had no response to treatment. After treatment, the serum AchR-Ab and CAE-Ab levels of patients, which were remarkably lower than those before treatment (P < 0.001), were remarkably lower in the remission group than in the improvement group (P < 0.001) and remarkably lower in the improvement group than in the ineffective group (P < 0.001). The ordinal logistic regression analysis concluded that the levels of AchR-Ab and CAE-Ab were related to therapeutic effect, i.e. the lower the serum AchR-Ab and CAE-Ab levels, the better the therapeutic effect. TS can reduce the serum AchR-Ab and CAE-Ab levels in patients with thymoma, and serum AchR-Ab and CAE-Ab levels can reflect the therapeutic effect, providing reference value. [ABSTRACT FROM AUTHOR]

A centrifugal pump whose open impeller was made of polycarbonate was adopted to explore the influence of different concentrations of slender fiber particles on the external characteristics of the pump and to obtain the motional characteristics of the particles in the channels of the impeller. The external characteristics of the pump were used to determine the performance of the pump. A high-speed photographic system was used to analyze the motion of fiber particles in the channels of the impeller. Changes in the head and efficiency of the pump and changes in the distribution of fiber particles in impeller channels were obtained under different concentrations of fiber particles and different flow rates of fiber suspensions. The head associated with the transport of a fiber suspension whose mass concentration of fiber particles was 0.15% and the head associated with the transport of a fiber suspension whose mass concentration of fiber particles was 0.30% did not differ greatly from the head associated with the transport of clean water. However, compared to the transport of clean water, the transport of the fiber suspensions improved the efficiency of the pump. When the pump transported the fiber suspension whose mass concentration of fiber particles was 0.30%, on average, the efficiency of the pump increased by 8.49%. When the flow rates of the fiber suspensions increased, the uniformity of the distribution of the particles increased. When entering the impeller, a small number of fiber particles showed rotating and flapping motions. However, the motions gradually disappeared as the particles left the impeller. At a constant radius (i.e., 75% and 95% radius, respectively), the velocity profile increased gradually when the mass concentration of fiber particles increased from 0.1% to 0.15%. It is manifest that fiber suspension undergoes less flow loss as the mass concentration of fiber particles increases. [ABSTRACT FROM AUTHOR]

This paper presents studies on a robust adaptive output feedback stabilisation for a class of nonlinear systems, which is subjected to parametric uncertainties and disturbances. The disturbances are considered to be general, i.e. both the matched and unmatched ones are present. A novel robust adaptive control is developed for this problem. A technique is employed to avoid the difficulty in handling the nonlinear gain functions associated with the disturbances. For this, a new Lemma is obtained to handle the nonlinear functions that simplify the controller derivation steps. The unknown parameters and disturbances are tackled by deriving the tuning functions using a backstepping design. Finally, simulation is carried out to validate and show the effectiveness of the proposed robust controller. [ABSTRACT FROM AUTHOR]

Evidence about the effect of age at menarche (AAM) on blood pressure (BP) has largely been drawn from studies in developed countries. Studies in developing countries are expanding recently but have not been summarised. To systematically explore the association between AAM and BP and the potential modifiers in developing countries. We searched PubMed, Embase, and Web of Science for publications until March 2022. A random-effects model was used to calculate the pooled relative risk (RR) with 95% confidence interval (CI). Twenty studies were eligible. In studies with participants' mean age at BP assessment <55 years, women in the oldest group as compared with the middle or the youngest group of AAM had a higher risk of hypertension in those studies without adjustment for confounders (RR 1.79, 95% CI 1.41–2.28, I2=97.0%), those with adjustment for confounders excluding adiposity (1.25,1.04–1.51, I2=84.8%), and those with adjustment for confounders including adiposity (1.38,1.03–1.86, I2=91.8%). In studies with participants' mean age at BP assessment ≥55 years, no significant differences were found for studies without adjustment for confounders (RR 1.07, 95% CI 0.78–1.47, I2=90.3%), studies with adjustment for confounders excluding adiposity (0.85, 0.78–0.92, I2=12.3%), or studies with adjustment for confounders including adiposity (0.95, 0.80–1.11, I2=45.5%). A similar association was observed between AAM and baseline systolic BP and diabolic BP. Late menarche was associated with a higher risk of BP and this association was modified by age and adiposity in developing countries. [ABSTRACT FROM AUTHOR]

The (FeCoNi)86Ti7Al7 multi-principal-element alloy with a dual heterogeneous microstructure was successfully fabricated by selective laser melting, exhibiting an excellent combination of strength (ultimate tensile strength, 1085.2 ± 23.2 MPa) and ductility (30.5 ± 2.6%). It is evidenced that the joint effects of the hetero-deformation induced hardening from grains with heterogeneous geometrically necessary dislocations densities, in-situ formed B2 phase, and the coherent precipitation hardening from in-situ formed nano L12 phase were responsible for the strength. This work sheds light on the feasibility of simplifying the production of multi-mechanism strengthened alloys within one step and paves a new avenue to produce high-performance complex-shaped components. (FeCoNi)86Ti7Al7 multi-principal-element alloy exhibiting heterogeneity on the grains structure and in-situ precipitation was successfully fabricated by selective laser melting. It shows both good tensile strength and ductility. [ABSTRACT FROM AUTHOR]

A simple dynamic positioning (DP) system has been developed for the scaled model of a novel twin-lift decommissioning operation. Such a decommissioning solution involves the two semi-submerged vessels transporting the topside to another vessel. And it requires the synchronised motion of the two topside-carried vessels at a low speed, under the environmental disturbances. In order to ensure efficiency and safety, model tests with a scaling factor of 1:37 have been carried out in the wave tank. The DP system in the experiment consists of a 3-Degree of Freedom (3DoF) motion equation, a Proportional–Integral–Derivative (PID) controller and a thrust allocation algorithm. This paper investigates the motion response of each vessel under the random wave and constant wind of different angles, to assess the low-speed manoeuvring performance. It is found that the given control scenarios allow the twin-lift decommissioning system to yield good motion performance under operational conditions. [ABSTRACT FROM AUTHOR]

The different fretting wear behaviors of alloy 690TT in air and in a flowing nitrogen environment were revealed. Moreover, grain refinement to the nanoscale caused by fretting wear in nitrogen was investigated. The results showed that when compared with an air environment, the coefficient of friction in nitrogen was slightly higher due to direct contact between the metals with strong adhesion, which resulted in a smaller wear width and volume. Fretting in nitrogen ran in the partial slip regime with the wear mechanisms including the formation of fatigue cracks and severe plastic deformation (SPD). The formation of fatigue cracks resulted in the maximum wear depth occurring at the edge of the wear scar. Fretting in air ran in the gross slip regime with the wear mechanisms oxidation, delamination, and SPD. Due to SPD during fretting wear in nitrogen, nanotwins were formed in fine crystals, which caused the original grains to be divided into twin–matrix lamellae. The interaction of nanotwins with the dislocation arrays further subdivided the twin–matrix lamellae into nanoblocks and randomly oriented nanograins. [ABSTRACT FROM AUTHOR]

Purpose: To understand the relationship between body mass index (BMI), age, prostate volume (PV), prostate-specific antigen (PSA), International Prostate Symptom Score (IPSS) and quality of life (QoL) in Zhengzhou.Materials and Methods: In the cross-sectional study, men living in Zhengzhou were invited to participate in this study. Men who were 40 years or older were subjected to the IPSS and related examination. A total of 1360 participants were included. Body mass index < 18.5 kg/m2 was determined as underweight, 18.5-24.99 kg/m2 normal, 25-29.99 kg/m2 overweight, and ≥30 kg/m2 obese.Results: The mean BMI was 24.92 ± 3.37 kg/m2. The mean PSA was 1.06 ± 0.85 ng/mL. The mean PV was 20.10 ± 9.96 mL. The mean age was 62.72 ± 11.03 years. The mean IPSS was 5.87 ± 3.48 scores. The mean QoL was 2.33 ± 1.28 scores. PSA showed a significant tendency to decrease with increasing BMI (r = -0.061, p = 0.018, ptrend = 0.037). The same with age (r = -0.109, p < .001; ptrend = .045). But the result suggested that both IPSS and QoL were positively correlated with BMI (r = 0.120, p < .001, ptrend < .001; r = 0.083, p = .001, ptrend = .021, respectively). PV increased with increasing BMI (r = 0.110, p < .001, ptrend = 0.045 ).Conclusions: Age, PSA decreased with increasing BMI. But larger PV, IPSS, and QoL were associated with higher BMI. [ABSTRACT FROM AUTHOR]

A heterogeneous (α + β) titanium alloy with extraordinary tensile properties was prepared. The heterogeneous microstructures, consisting of soft βfiber and hard (α + β)matrix, were achieved by controlling the distribution of β-stabilizing element. The heterogeneous alloy exhibits ultra-high strength of 1634 MPa with reasonable ductility, which is much higher compared to the homogeneous counterpart. The plastic incompatibility of the βfiber and (α + β)matrix produces hetero-deformation induced (HDI) hardening, which is the main reason for the enhanced strength. Moreover, the α-twining and martensitic transformation are responsible for the good ductility. This work provides a new strategy to achieve superior strength-ductility combination for multi-phase alloys. Heterogeneous phase-distribution was realized in an (α + β) titanium alloy to achieve superior strength-ductility combination based on hetero-deformation induced hardening. [ABSTRACT FROM AUTHOR]

The 28 nm system-on-chip (SoC) was irradiated by 12 MeV electron at the China Institute of Atomic Energy (CIAE) for the first time. Soft errors in the on-chip memory (OCM), D-Cache, Register and BRAM blocks were investigated. The obtained device cross sections are almost in the range of 10−13 cm2 to 10−11 cm2 for the blocks. The results demonstrate that electron fluence per pulse and the corresponding prompt dose rates have no influence on the soft errors in 28 nm SoC. The discrepancy was analyzed between proton and electron inducing soft errors in D-Cache and BRAM blocks, too. The secondary electron is considered as the dominant reason for soft errors caused by 12 MeV electron in 28 nm SoC. [ABSTRACT FROM AUTHOR]

This paper presents a gain scheduling approach for achieving the consensus tracking of multi-agent systems with actuator saturation. We first construct a series of nesting ellipsoid invariant sets associated with consensus errors. When the consensus errors stay between the two ellipsoid invariant sets, the feedback gains keep constant, but when the consensus errors enter into the smaller ellipsoid invariant set, the feedback gains abruptly become larger. By combining this gain scheduling technique and the parametric Lyapunov equations, we, respectively, design state and output feedback gain scheduling protocols. Their main advantage, in comparison with the fixed case, is that the convergence rate of consensus tracking can be enhanced by scheduling the gain parameters. Numerical simulations verify the effectiveness of theoretical analysis. [ABSTRACT FROM AUTHOR]

This paper investigates the leader–follower formation problem of underactuated surface vessels. Velocities of both leader and follower vessels are unavailable. Model uncertainties and ocean disturbances are also considered. By incorporating adaptive control, neural networks (NNs), the high-gain observer (HGO) and the minimal learning parameter (MLP) algorithm in the backstepping procedure, a novel adaptive output-feedback formation control scheme is developed. We show that formation errors can be guaranteed to be semiglobally uniformly ultimately bounded (SGUUB) with the proposed controller. Compared with existing methods, the formation can be achieved only with position and yaw angle of both leader and follower. Meanwhile, the developed scheme can enhance the robustness of the closed-loop system with less computational effort, where only two online parameters need to be tuned. Simulation and comparison results are provided to illustrate the effectiveness of theoretical results. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this study was the investigation of age- and sex-associations in a set of blood plasma metabolites in healthy male and female subjects. Methods: A comparison study design with male and female subjects of various ages was used. Metabolic profiling was performed using electrospray ionization tandem mass spectrometry that yielded 186 metabolite concentrations for each study participant. The key age-related metabolites were identified using an integrative analysis of absolute concentrations, metabolite ratios and the differential correlation of pairwise metabolite concentrations. All of the age-associated metabolites were adjusted prior to the analysis to account for differences in Body Mass Index (BMI). Results: A total of 236 plasma samples from 140 female and 96 male subjects aged 20 to 82 years-old were collected and analyzed in the study. 13 and 14 age-associated metabolites (|r| > 0.33 and p < 6.6×10−5), 438 and 337 age-associated metabolite ratios (|r| > 0.37 and p < 3.5×10−6), and 5 and 10 core metabolites were discovered in the female and male groups, respectively. 80% of the metabolites displaying associations with age belonged to sphingolipids and phosphatidylcholines, and the two sexes shared less than 50% of the age-associated metabolites. Conclusion: The study found that changes in metabolite concentrations, metabolite ratios and differential correlations were age and sex-specific. [ABSTRACT FROM AUTHOR]

An analytical H2 input load disturbance rejection (ILDR) controller design approach is presented for the synchronised output regulation (SOR) of homogeneous time-delayed multi-agent systems. First, a closed-loop multi-input multi-output framework with transfer functions is introduced, and an SOR condition is given. Second, the decomposition method is utilised to simplify the analysis of internal stability and H2 performance index of the whole system to a set of independent optimisation problems with respect to the eigenvalues of the topology matrix. Finally, for each decomposed subsystem, the H2 optimal ILDR controller can be computed from all the stabilising controllers. By comparison with the conventional given-structured controllers, the contributions of the new approach are that the design procedure is calculated analytically for multi-agent systems with input disturbances, and a simple quantitative tuning way is developed to trade-off the nominal performance and robustness. The simulation example shows the effective ILDR capability of the proposed control strategy. [ABSTRACT FROM AUTHOR]

This paper designs the event-triggered non-fragile state estimator for a class of time-delayed complex networks with randomly occurring sensor saturations (ROSSs) and estimator gain variations on the basis of measurements from partial nodes. Both the time-varying state delays and the stochastic disturbances are considered in the network model. A Bernoulli-distributed white sequence is utilized to reflect the phenomenon of ROSSs. Two sequences of Gaussian distributed random variables combined with the multiplicative norm-bounded uncertainties are used to characterize the randomly occurring gain variations in the estimators. An event generator function is employed to regulate the transmission of data from the sensor to the estimator. The aim of this paper is to design an exponentially ultimately bounded state estimator in mean square through measurement outputs from a partial of network nodes under the event-triggered mechanism. With the help of Lyapunov-Krasovskii functional and stochastic analysis techniques, sufficient conditions are acquired for the existence of the desired state estimator which ensures that the estimation error dynamics is exponentially ultimately bounded in mean square, and then the estimator gain matrices can be computed via the software Matlab. A simulation example is provided to demonstrate the effectiveness of the proposed state estimation method. [ABSTRACT FROM AUTHOR]

Objective To observe the improvement of negative affect disorders in patients with cerebral infarction and dysphagia by neuromuscular electrical stimulation. Methods One hundred and twelve patients with cerebral infarction and dysphagia were selected and randomized into treatment (n = 59) and control (n = 53) groups. Similar swallowing function was found in both groups before treatment: (1) Water-drinking test in the treatment group proved swallowing function Level III in 24 cases, Level IV in 22 cases and Level V in 13 cases; (2) in the control group, swallowing function was Level III in 21 cases, Level IV in 20 cases and Level V in 12 cases. Both groups received conventional drug therapy and swallowing training. The treatment group additionally received neuromuscular electrical stimulation. Both groups underwent water-drinking test evaluation, Hamilton Anxiety Scale test, and Hamilton Depression Scale test before and after treatment. Results After two courses of treatment, the rate of improvement in swallowing function was 88.1% in the treatment group while 69.8% in the control group. Somatic anxiety, psychogenic anxiety and total scores in the Hamilton Anxiety Scale in the treatment group were improved to varying degrees compared to the control group (P < 0.01). Anxiety, cognitive disorder, psychomotor retardation and total scores in the Hamilton Depression Scale in the treatment group were improved to varying degrees compared to the control group (P < 0.05). Conclusion Patients with cerebral infarction and dysphagia have varying degrees of anxiety, depression, and other negative affect disorders, which could be minimized by neuromuscular electrical stimulation in conjunction with conventional therapy. [ABSTRACT FROM AUTHOR]

A systematical design method of optimal control for non-minimum phase integrating processes with time delay using disturbance observer-based (DOB) control scheme is presented. All stabilising controllers and the filter of DOBs for integrating plants are developed. Then the optimal set-point tracking controller and the optimal filter of DOB are systematically derived by minimising the H2 norm performance specifications. The proposed design method has three main advantages. First, the design procedure is systematical and simple. Specified weight functions are chosen for step inputs and inputs similar to steps. The designed set-point tracking controller and the filter of DOB are given in analytical forms. Second, the designed set-point tracking controller and the filter of the DOB are optimal. They are derived from minimising the performance indexes of set-point tracking and input load disturbance rejection (ILDR). Finally, the set-point tracking performance specification and ILDR specification can be quantitatively achieved by conveniently tuning the adjustable parameters. Numerical simulations are given to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Precision medicine has been a hot topic in drug development over the last decade. Biomarkers have been proven useful for understanding the disease progression and treatment response in precision medicine development. Advancement of high-throughput omics technologies has enabled fast identification of molecular biomarkers with low cost. Although biomarkers have brought many promises to drug development, steep challenges arise due to a large amount of data, complexity of technology, and lack of full understanding of biology. In this article, we discuss the technologies and statistical issues that are related to omics biomarker discovery. We also provide an overview of the current development of biomarker-enabled cancer clinical trial designs. [ABSTRACT FROM AUTHOR]

This paper presents an output feedback indirect dynamic inversion (IDI) approach for a class of uncertain nonaffine systems with input unmodelled dynamics. Compared with previous approaches to achieve performance recovery, the proposed method aims at dealing with a broader class of nonaffine-in-control systems with triangular structure. An IDI state feedback law is designed first, in which less knowledge of the model plant is needed compared to earlier approximate dynamic inversion methods, thus yielding more robust performance. After that, an extended high-gain observer is designed to accomplish the task with output feedback. Finally, we prove that the designed IDI controller is equivalent to an adaptive proportional-integral (PI) controller, with respect to both time response equivalence and robustness equivalence. The conclusion implies that for the studied strict-feedback non-affine systems with unmodelled dynamics, there always exits a PI controller to stabilise the systems. The effectiveness and benefits of the designed approach are verified by three examples. [ABSTRACT FROM PUBLISHER]

Background: Increased plasma homocysteine (Hcy) levels are a risk factor for stroke and can be reduced with folic acid therapy. Therefore, it is extremely important for patients with hyperhomocysteinemia (HHcy) to obtain the normal level of Hcy after folate intervention. Thus far, few studies have reported the effective rate defined as percentage of patients who achieved normal plasma Hcy levels after folic acid therapy.Objectives: The present study aimed to investigate the effective rate of folic acid for the treatment of HHcy and the impact of plasma baseline Hcy levels and the compliance of oral folic acid on the efficacy.Methods: A total of 858 patients with HHcy were treated with oral folic acid (5 mg/d) for 3 months. Fasting blood samples collected at baseline and at the end of treatment were assayed for plasma Hcy levels.Results: After 3 months of treatment, the plasma Hcy levels of 484 patients were reduced to below the normal levels (15 μmol/L), corresponding to an effective rate of 56.41%. The average of Hcy levels decreased by 28.05%. The effective rates of folic acid therapy in a mild Hcy elevated group and an intermediate Hcy elevated group were 61.34% and 27.78%, respectively (p = 0.000). The effective rates among patients with good and poor compliance of oral folic acid were 65.29% and 35.18%, respectively (p = 0.000).Conclusions: More than 40% patients with HHcy failed to reach the normal range (5-15 μmol/L) after 3 months of folic acid supplementation. Further prospective studies are warranted to explore the reasons for failure. [ABSTRACT FROM AUTHOR]

In this note, the authors study the tracking problem for uncertain nonlinear time-delay systems with unknown non-smooth hysteresis described by the generalised Prandtl–Ishlinskii (P-I) model. A minimal learning parameters (MLP)-based adaptive neural algorithm is developed by fusion of the Lyapunov–Krasovskii functional, dynamic surface control technique and MLP approach without constructing a hysteresis inverse. Unlike the existing results, the main innovation can be summarised as that the proposed algorithm requires less knowledge of the plant and independent of the P-I hysteresis operator, i.e. the hysteresis effect is unknown for the control design. Thus, the outstanding advantage of the corresponding scheme is that the control law is with a concise form and easy to implement in practice due to less computational burden. The proposed controller guarantees that the tracking error converges to a small neighbourhood of zero and all states of the closed-loop system are stabilised. A simulation example demonstrates the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

In this paper, an H2optimal input-load disturbance rejection (ILDR) controller for integrating processes with dead time is proposed based on the internal model control principle. The main contribution of this work is that the optimal solution under ILDR criterion for integrating processes with dead time and input constant disturbances has been derived based on algebraic theory. To further improve the performance for both set-point tracking and input disturbance rejection, a two-degree-of-freedom (TDOF) control design method has also been developed. Compared with previous advanced control methods, the proposed design method has three main advantages. First, the optimal ILDR controller is derived systematically on the basis of algebraic theory. The designed controller is given in an analytical form. Second, a simple tune principle is developed. The set-point tracking performance specification and robustness stability specification can be quantitatively achieved by monotonously tuning the performance degree in the designed controller. Finally, both optimal set-point tracking performance and input disturbance rejection can be achieved by the proposed TDOF control structure. Numerical simulations are given to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Adaptive tracking control of a class of MIMO nonlinear system preceded by unknown hysteresis is investigated. Based on dynamic surface control, an adaptive robust control law is developed and compensators are designed to mitigate the influences of both the unknown bounded external uncertainties and the unknown Prandtl–Islinskii hysteresis. By adopting the low-pass filters, the explosion of complexity caused by tedious computation of the time derivatives of the virtual control laws is overcome. With the proposed control scheme, the closed-loop system is proved to be semi-globally ultimately bounded by the Lyapunov stability theory, and the output of the controlled system can track the desired trajectories with an arbitrarily small error. Finally, numerical simulations are given to verify the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

In this paper, the structure feature of the inverse of a multi-input/multi-output square transfer function matrix is explored. Instead of complicated advanced mathematical tools, we only use basic results of complex analysis in the analysing procedure. By employing the Laurent expression, an elegant structure form of the expansion is obtained for the transfer function matrix inverse. This expansion form is the key of deriving an analytical solution to the inner–outer factorisation for both stable plants and unstable plants. Different from other computation algorithm, the obtained inner–outer factorisation is given in an analytical form. The solution is exact and without approximation. Numerical examples are provided to verify the correctness of the obtained results. [ABSTRACT FROM PUBLISHER]

In this paper, an H2analytical decoupling control scheme with multivariable disturbance observer for both stable and unstable multi-input/multi-output (MIMO) systems with multiple time delays is proposed. Compared with conventional control strategies, the main merit is that the proposed control scheme can improve the system performances effectively when the MIMO processes with severe model mismatches and strong external disturbances. Besides, the design method has three additional advantages. First, the derived controller and observer are given in analytical forms, the design procedure is simple. Second, the orders of the designed controller and observer are low, they can be implemented easily in practice. Finally, the performance and robustness can be adjusted easily by tuning the parameters in the designed controller and observer. It is useful for practical application. Simulations are provided to illustrate the effectiveness of the proposed control scheme. [ABSTRACT FROM AUTHOR]

An essential step in many controller design approaches is computing the inverse of the plant. For a square plant, its inverse is stable if the plant is minimum phase (MP). Nevertheless, this conclusion does not hold for a non-square plant. In this paper, the pole feature of the Moore–Penrose pseudo-inverse of a non-square transfer function matrix is analysed. Instead of complicated advanced mathematical tools, only basic results of polynomial theory and the Binet–Cauchy theorem are used in the analysing procedure. The condition for testing the stability of the Moore–Penrose pseudo-inverse of an MP non-square transfer function matrix is given. This condition implies that the Moore–Penrose pseudo-inverse of a non-square transfer function matrix cannot be directly used as the optimal controller. Numerical examples are provided to illustrate the correctness of the condition. [ABSTRACT FROM PUBLISHER]

In this paper, we mainly focus on the problem of quantised feedback stabilisation of a stochastic discrete-time linear system with white noise input. The dynamic quantiser is used here. The stability of the system under state quantisation and input quantisation is analysed in detail, respectively. Both the convergence of the state's mean and the boundedness of the state's covariance matrix norm should be considered when analysing its stability. It is shown that for the two situations of the state quantisation and the input quantisation, if the system without noise input can be stabilised by a linear feedback law, it must be stabilised by the dynamic quantised feedback control policy. The sufficient conditions that the dynamic quantiser should satisfy are given. Using the results obtained in this paper, one can test whether the stochastic system is stabilisable or not. Numerical examples are given to show the effectiveness of the results. [ABSTRACT FROM PUBLISHER]

Objective: Music-supported therapy (MST) is a new approach for motor rehabilitation of stroke patients. Recently, many studies have demonstrated that MST improved the motor functions of post-stroke patients. However, the underlying mechanism for this effect is still unclear. It may result from repeated practice or repeated practice combined with musical stimulation. Currently, few studies have been designed to clarify this discrepancy. In this study, the application of "mute" musical instruments allowed for the study of music as an independent factor. Methods: Thirty-three post-stroke patients with no substantial previous musical training were included. Participants were assigned to either audible music group (MG) or mute music group (CG), permitting observation of music's independent effect. All subjects received the conventional rehabilitation treatments. Patients in MG (n = 15) received 20 extra sessions of audible musical instrument training over 4 weeks. Patients in CG (n = 18) received "mute" musical instrument training of the same protocol as that of MG. Wolf motor function test (WMFT) and Fugl-Meyer assessment (FMA) for upper limbs were utilised to evaluate motor functions of patients in both groups before and after the treatment. Three patients in CG dropped out. Results: All participants in both groups showed significant improvements in motor functions of upper limbs after 4 weeks' treatment. However, significant differences in the WMFT were found between the two groups (WMFT-quality: P = 0.025; WMFT-time: P = 0.037), but not in the FMA (P = 0.448). In short, all participants showed significant improvement after 4 weeks' treatment, but subjects in MG demonstrated greater improvement than those in CG. Discussion: This study supports that MST, when combined with conventional treatment, is effective for the recovery of motor skills in post-stroke patients. Additionally, it suggests that apart from the repetitive practices of MST, music may play a unique role in improving upper-limb motor function for post-stroke patients. [ABSTRACT FROM AUTHOR]

This paper addresses the fault detection observer design problem for linear parameter-varying systems. Two finite frequency performance indexes are introduced to measure the fault sensitivity and the disturbance robustness. First, theH−index fault sensitivity condition in finite frequency domain is obtained by generalised Kalman–Yakubovich–Popov lemma and new linearisation techniques. Then, with the aid of Kalman–Yakubovich–Popov lemma and projection lemma, the stability and robustness conditions are derived. It turns out that the non-convexity problem which is caused by dealing with the above three conditions can be translated into a bilinear matrix inequality optimisation problem by increasing the dimensions of slack variable matrix. An iterative linear matrix inequality algorithm is proposed to get the solution. The effectiveness of the filter is shown via three numerical examples. [ABSTRACT FROM PUBLISHER]