This paper investigates the event-triggered tracking control of the nonstrict-feedback nonlinear system with time-varying disturbances. While the fuzzy logic systems (FLSs) approximate the unknown ...dynamics, an event-triggered compound learning algorithm is originally developed to accurately estimate the total uncertainties. By referring to an event-triggered adaptive model, the control laws are derived without provoking the problem of “algebraic loop,” seeing Remark
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. The command filters are employed to generate the continuous substitutes for both the virtual control laws and their derivatives, so as to solve the recently proposed problem of “jumps of virtual control laws” arising in the backstepping-based event-triggered control (ETC). The triggering condition is constructed to guarantee the similarity between the adaptive model and the original system. Estimation of optimal fuzzy weights and compound disturbances follows from the event-triggered update laws. While the satisfactory learning performance is achieved, the proposed control scheme can guarantee the semi-globally uniformly ultimate boundedness (SGUUB) of all the tracking errors. Finally, a numerical experiment verifies the effectiveness of the proposed control scheme.
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This note aims to solve the speed optimization and path following control for sail-assisted ships. The ideology of retrofitting a common bulk carrier with wing sails is investigated. Based on an ...established mathematical model with four degrees of freedom, we proceed with the subsequent analysis. First, a novel speed optimization scheme combining the extremum seeking (ES) algorithm with the self-tuning fuzzy logic system is proposed. After adequate online training, the fuzzy logic system is capable to maximize the ship's speed with less chattering. Next, an adaptive fuzzy control law for such a ship is developed under the skeleton of line of sight (LOS) guidance. The uncertainties are offset by fuzzy approximation and the least parameters updating is acquired. The derived control outputs are characterized by rudder angles, which conforms to the nautical practice. Finally, the proposed scheme is testified in the simulated sea environment.
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To address the phenomenon of many small and hard-to-detect objects in drone images, this study proposes an improved algorithm based on the YOLOv7-tiny model. The proposed algorithm assigns anchor ...boxes according to the aspect ratio of ground truth boxes to provide prior information on object shape for the network and uses a hard sample mining loss function (HSM Loss) to guide the network to enhance learning from hard samples. This study finds that the aspect ratio difference of vehicle objects under drone perspective is more obvious than the scale difference, so the anchor boxes assigned by aspect ratio can provide more effective prior information for the network than those assigned by size. This study evaluates the algorithm on a drone image dataset (DroneVehicle) and compares it with other state-of-the-art algorithms. The experimental results show that the proposed algorithm achieves superior average precision values on both infrared and visible light images, while maintaining a light weight.
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To compared the presentation of research priorities in the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) clinical practice guidelines (CPGs) developed under the guidance ...of the GRADE working group or its two co-chair, and the Chinese CPGs.
This was a methodological empirical analysis. We searched PubMed, Embase, and four Chinese databases (Wanfang, VIP Database for Chinese Technical Periodicals, China National Knowledge Infrastructure and Chinese Biomedical Literature Database) and retrieved nine Chinese guideline databases or Society websites as well as GRADE Pro websites. We included all eligible GRADE CPGs and a random sample of double number of Chinese CPGs, published 2018 to 2022. The reviewers independently screened and extracted the data, and we summarized and analyzed the reporting on the research priorities in the CPGs.
Of the 135 eligible CPGs (45 GRADE CPGs and 90 Chinese CPGs), 668, 138 research priorities were identified respectively. More than 70% of the research priorities in GRADE CPGs and Chinese CPGs had population and intervention (PI) structure. 99 (14.8%) of GRADE CPG research priorities had PIC structures, compared with only 4(2.9%) in Chinese. And 28.4% (190) GRADE CPG research priorities reflected comparisons between PICO elements, approximately double those in Chinese. The types of research priorities among GRADE CPGs and Chinese CPGs were mostly focused on the efficacy of interventions, and the type of comparative effectiveness in the GRADE research priorities was double those in Chinese.
There was still considerable room for improvement in the developing and reporting of research priorities in Chinese CPGs. Key PICO elements were inadequately presented, with more attention on intervention efficacy and insufficient consideration given to values, preferences, health equity, and feasibility. Identifying and reporting of research priorities deserves greater effort in the future.
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This article investigates the adaptive fuzzy output-feedback path-following control of autonomous surface vessels (ASVs) via the event-triggered mechanism, in which the fuzzy logic systems (FLSs) are ...employed to approximate the uncertainties. By transforming the estimation errors, an adaptive fuzzy observer is established to estimate the kinematic states of the ASV, and a serial-parallel estimation model is fabricated based on this observer. By combining the tracking errors with the prediction errors between the observer and the serial-parallel estimation model, the composite adaptive laws are devised for the weights of the FLSs. Then, the event-triggered controller is developed in the channel of sensor to controller, in which the estimated kinematic states, the positional coordinates, and the heading angle of the ASV are sampled only when the triggering condition is violated. In this article, we put forward the problem of "jumps of virtual control laws" at the triggering instants, which commonly exists in the backstepping-based event-triggered control (ETC) in the channel of sensor to controller. To solve this problem, the dynamic surface filters are employed to generate the continuous substitutes for the virtual control laws. The proposed scheme can guarantee at least the similar control performance compared with its continuous alternatives while it importantly reduces the communication burden through the ETC and can enhance the estimation accuracy of the observer by applying the composite learning. All the errors are ensured to be semiglobally uniformly ultimately bounded in the closed-loop system. Finally, the effectiveness of the proposed scheme is verified through the numerical experiment.
Health equity can narrow the health gap between different groups and enable citizens to enjoy fair health services. Clinical practice guideline makers have been paying more and more attention to ...health equity, and exploring and applying the consideration to the development of corresponding guidelines. However, existing clinical practice guideline development gives little consideration to the structured and systematic construction of health equity, and the guidance for future guidelines is limited. This paper aims to put forward methodological suggestions for in-depth consideration of health equity in clinical practice guideline development, withthe hope of providing reference for guideline developers.
Purpose
The optimal method for achieving proper graft tension during patellofemoral ligament reconstruction is a topic of debate. In the past, a digital tensiometer was used to simulate the knee ...structure, and a tension of approximately 2N was identified as suitable for restoring the patellofemoral track. However, it is unclear whether this tension level is sufficient during the actual surgery. The objective of this study was to verify the efficacy of graft tension using a digital tensiometer for medial patellofemoral ligament (MPFL) reconstruction and to conduct a mid-term follow-up.
Methods
The study enrolled 39 patients who had experienced recurrent patellar dislocation. Preoperative computed tomography scans and X-rays confirmed patellar instability, patellar tilt angle patellar congruence angle and the history of dislocation and patellar apprehension test. Knee function was evaluated using preoperative and postoperative Lysholm and Kujala scores.
Results
The study included 39 knees, comprising 22 females and 17 males, with an average age of 21.10 ± 7.26. The patients were followed up for at least 24 months through telephone or face-to-face questionnaires. All patients had a preoperative history of ≥2 patellar dislocations, none of which were surgically treated. During surgery, all patients underwent isolated MPFL reconstruction and lateral retinacula release. The mean Kujala and Lysholm scores were 91.28 ± 4.90 and 90.67 ± 5.15, respectively. The mean PTA and PCA were 11.5 ± 2.63 and 2.38 ± 3.58, respectively. The study found that a tension of approximately 27.39 ± 5.57N (14.3–33.5N) was required to restore the patellofemoral track in patients with recurrent patellar dislocation. No patients required reoperation during the follow-up period. Overall, 36 out of 39 patients (92.31%) reported no pain when completing daily activities at the last follow-up.
Conclusion
In conclusion, a tension level of approximately 27.39 ± 5.57N is necessary to restore normal patellofemoral relationships during clinical practice, which indicates that using a tension of 2N is too low. The use of a tensiometer during patellofemoral ligament reconstruction is a more accurate and reliable surgical procedure for treating recurrent patellar dislocation.
Osteopontin plays critical roles in osteoarthritis (OA) by regulating the functions of osteoclasts. It is known that osteopontin can induce the expression of lncRNA HOX transcript antisense RNA ...(HOTAIR), indicating the involvement of HOTAIR in OA. This study was carried out to investigate the role of HOTAIR in OA.
Synovial fluid was extracted from both OA patients (n = 58) and healthy controls (n = 58). Expression of osteopontin and HOTAIR in synovial fluid was determined by RT-qPCR. Osteopontin was used to treat chondrocytes at dosages of 0, 1, 5 and 10 µg/ml, followed by measurement of HOTAIR expression by RT-qPCR. The role of osteopontin and HOTAIR overexpression, as well as HOTAIR knockdown in regulating the proliferation of chondrocytes was analyzed by cck-8 assay.
HOTAIR was upregulated in OA. A positive correlation between HOTAIR and osteopontin was observed. In the primary chondrocytes, osteopontin treatment increased HOTAIR expression, while HOTAIR overexpression and knockdown failed to significantly affect osteopontin expression. In addition, osteopontin and HOTAIR overexpression increased chondrocyte proliferation, while HOTAIRE knockdown decreased chondrocyte proliferation. In addition, HOTAIR knockdown reduced the effects of osteopontin treatment on cell proliferation.
Osteopontin-induced HOTAIR expression is involved in osteoarthritis by regulating cell proliferation.
The detection and tracking of small targets under low signal-to-clutter ratio (SCR) has been a challenging task for infrared search and track (IRST) systems. Track-before-detect (TBD) is a ...widely-known algorithm which can solve this problem. However, huge computation costs and storage requirements limit its application. To address these issues, a dynamic programming (DP) and multiple hypothesis testing (MHT)-based infrared dim point target detection algorithm (DP–MHT–TBD) is proposed. It consists of three parts. (1) For each pixel in current frame, the second power optimal merit function-based DP is designed and performed in eight search areas to find the target search area that contains the real target trajectory. (2) In the target search area, the parallel MHT model is designed to save the tree-structured trajectory space, and a two-stage strategy is designed to mitigate the contradiction between the redundant trajectories and the requirements of more trajectories under low SCR. After constant false alarm segmentation of the energy accumulation map, the preliminary candidate points can be obtained. (3) The target tracking method is designed to eliminate false alarms. In this work, an efficient second power optimal merit function-based DP is designed to find the target search area for each pixel, which greatly reduces the trajectory search space. A two-stage MHT model, in which pruning for the tree-structured trajectory space is avoided and all trajectories can be processed in parallel, is designed to further reduce the hypothesis space exponentially. This model greatly reduces computational complexity and saves storage space, improving the engineering application of the TBD method. The DP–MHT–TBD not only takes advantage of the small computation amount of DP and high accuracy of an exhaustive search but also utilizes a novel structure. It can detect a single infrared point target when the SCR is 1.5 with detection probability above 90% and a false alarm rate below 0.01%.
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This article investigates the output-feedback control of a class of stochastic nonlinear system with time-varying delay and unknown dead zone. A robust neural stabilizing algorithm is proposed by ...using the circle criterion, the NNs approximation and the MLP（minimum learning parameter） technique. In the scheme, the nonlinear observer is first designed to estimate the unmeasurable states and the assumption ＂linear growth＂ of the nonlinear function is released. Furthermore, the uncertainty of the whole system（including the perturbation of time-varying delay） is lumped and compensated by employing one RBF NNs（radial basis function neural networks）. Though, only two weight-norm related parameters are required to be updated online for the merit of the MLP technique. And the gain-inversion related adaptive law is targetly designed to mitigate the adverse effect of unknown dead zone. Comparing with the previous work, the proposed algorithm obtains the advantage：a concise form and easy to implementation due to its less computational burden. The theoretical analysis and comparison example demonstrate the substantial effectiveness of the proposed scheme.
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