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In the paper, iterative learning identification (ILI) and iterative learning control (ILC) for linear time-varying systems (LTVSs) with iteration varying lengths are investigated. A new ILI algorithm is firstly proposed, which makes the best of the available information in the incomplete iteration process. The identification speed of system parameters is improved. Then, on the basis of zero-compensation mechanism, a norm optimal ILC is presented for LTVSs with iteration varying lengths. From the perspective of iterative learning gain, the relationship between the two algorithms is analyzed when iterative learning gain is designed by using the identification model. Further, different from zero-compensation mechanism, a new compensation mechanism based on identification model obtained by ILI algorithm is proposed and an ILC algorithm by using compensation mechanism based on identification model is designed. The convergence speed for tracking performance of ILC algorithm with compensation mechanism based on identification model can be improved in comparison with the existing method. The convergence conditions of all algorithms are analyzed. An example is used to validate the designed algorithms.

This study considers the problem of providing efficient control of periodic-review production–inventory systems with perishable goods. The stock storage and replenishment is modelled as a first-order process with delay subject to external perturbations. The study investigates formally the classical delay compensation mechanisms used in inventory control and shows deficiencies of inventory position and Smith predictor-based concepts in the context of systems with deteriorating stock. Then, a new dead-time compensation mechanism is developed and non-linear control law synthesised. The proposed control scheme is proved robust with respect to arbitrary demand and delay variations.

Various quasi-zero stiffness (QZS) systems with high-static and low-dynamic stiffness (HSLDS) have been applied extensively to attenuate low-frequency vibrations. However, in the majority of cases, the negative stiffness unit exhibits nonlinear stiffness behaviors, and the method of realizing QZS is limited to compensate the nonlinear negative stiffness through linear springs. Hence, a novel linkage anti-vibration structure (LAVS) via linear positive and negative stiffness compensation mechanism is proposed and studied for exploring its advantages in low-frequency vibration isolation. The LAVS is composed of a symmetric polygonal structure (SPS) and a vertical spring. The static stiffness behavior is first investigated, revealing the inherent positive and negative stiffness compensation mechanism of linear springs to the SPS. By tuning structural parameters, the linear spring can completely compensate the linear negative stiffness of the SPS to achieve enhanced QZS over a larger stroke. Numerical simulations are carried out to verify the theoretical result and demonstrate the effectiveness of the presented stiffness compensation mechanism. Based on the Lagrange principle, a dynamic equation is established and then solved via the multiple scales method to obtain the displacement transmissibility. The effects of key parameters such as the rod lengths, equilibrium points and damping factors on the amplitude–frequency characteristics and vibration transmissibility are analyzed. Compared with a SMD and a typical X-shaped QZS isolation systems, the presented LAVS exhibits an enhanced QZS zone with a larger load capacity and can realize superb vibration isolation performance with guaranteed stable equilibrium. The proposed linear positive and negative stiffness compensation mechanism presents new insights for passive vibration isolation design in many engineering applications.

Balancing biodiversity conservation and the socioeconomic well-being of ethnic minority communities presents a significant challenge in protected areas (PAs). Ecological compensation (EC) is a crucial policy instrument for improving the livelihood of affected residents, but its application in ethnic minority-dominant regions is complicated by cultural differences and fragile economic foundations. This study evaluates the impact of an innovative hybrid EC mechanism, integrating cash payment, employment support, and education incentive, on the livelihood resilience of ethnic minority groups and identifies the most cost-effective mechanism. Using field data from rural households in Potatso National Park, analyzed through hierarchical multiple regression and scenario simulations within the Sustainable Livelihood Framework, the study finds that: (i) hybrid EC mechanisms significantly improve overall livelihoods, with households receiving employment support and education incentive showing 0.074 and 0.052 higher average livelihood score, respectively (on a 0–1 scale); (ii) different EC types have varied effects across households; and (iii) hybrid EC mechanisms increase social benefits by 6.97%–37.65%, with only a 1.30%–20.15% cost increase compared to baseline scenario. The findings highlight the need for diversified and optimized EC policies to improve livelihood resilience and maximize cost-effectiveness in PAs.

With the deep research of the fractional-order (FO) calculus theory, it has been found that the FO model can more realistically depict electromechanical devices with viscoelastic characteristics, such as the micro-electromechanical system (MEMS) resonator. Dynamic analysis is an important link to deeply understanding the dynamic characteristics of the system. Therefore, we established the FO model and FO circuit differential equation of the MEMS resonator and revealed that the chaos oscillation in the MEMS resonator is closely related to order α and parameter V AC through dynamic analysis including numerical simulation and analog circuit. For suppressing the chaos oscillation, we integrate the optimal control into the technical framework of fuzzy adaptive backstepping control, and then design a fuzzy adaptive optimal backstepping controller with a disturbance compensation mechanism. In the design of the controller, firstly, to reduce the damage caused by the matched disturbance for the control effect, a disturbance compensation mechanism based on the FO disturbance observer is proposed. Secondly, to approximate the unknown function in the FO MEMS resonator, the interval type-3 fuzzy logic system (IT3FLS) with adaptive law is constructed. Then, the Fourier series and IT3FLS are introduced to reconstruct the imprecise target trajectory, and the FO hyperbolic tangent tracking differentiator (HTTD) is introduced to deal with the “explosion of complexity” associated with traditional backstepping. Finally, the optimal control input is designed to improve the tracking accuracy of the controller and minimize the cost function, and the effectiveness and robustness of the designed controller are verified by simulation results.

The males and females of the brine shrimp Artemia franciscana are highly dimorphic, and this dimorphism is associated with substantial sex-biased gene expression in heads and gonads. How these sex-specific patterns of expression are regulated at the molecular level is unknown. A. franciscana also has differentiated ZW sex chromosomes, with complete dosage compensation, but the molecular mechanism through which compensation is achieved is unknown. Here, we conducted CUT&TAG assays targeting 7 post-translational histone modifications (H3K27me3, H3K9me2, H3K9me3, H3K36me3, H3K27ac, H3K4me3, and H4K16ac) in heads and gonads of A. franciscana, allowing us to divide the genome into 12 chromatin states. We further defined functional chromatin signatures for all genes, which were correlated with transcript level abundances. Differences in the occupancy of the profiled epigenetic marks between sexes were associated with differential gene expression between males and females. Finally, we found a significant enrichment of the permissive H4K16ac histone mark in the Z-specific region in both tissues of females but not males, supporting the role of this histone mark in mediating dosage compensation of the Z chromosome.

Compulsive smartphone use has attracted extensive social attention because of serious and even fatal outcomes associated with it. However, there has been little theory-driven research systematically investigating the mechanism of compulsive behavior in smartphone use. Although a significant line of literature exists in the area of personal-computer based technology addiction, the mechanism underpinning compulsive smartphone use differs significantly because the unique and specific characteristics of smartphones have given rise to a fundamentally different usage context with new usage behavioral patterns. In order to comprehensively theorize this issue, we first defined compulsive behavior in smartphone use, focusing on mobile social networking services (SNSs) in particular, and then extended the stimulus-response-reinforcement framework to investigate the theoretical network of compulsive use of mobile SNSs. We used online survey data from 368 active mobile SNS users in China to empirically test and validate the proposed model and hypotheses. Our results indicate that both positive and negative reinforcements, as well as the compensatory component, invoke the feeling of urge that leads to compulsive mobile SNS use. The positive effects of interactivity as an incentive stimulus on those reinforcements and compulsive mobile SNS use were also found to be significant.

Pre-existing or enhanced cognitive abilities influence symptom onset and severity in neurodegenerative diseases, which improve an individual’s ability to deal with neurodegeneration. This process is named cognitive reserve (CR), and it has acquired high visibility in the field of neurodegeneration. However, the investigation of CR has been neglected in the context of cerebellar neurodegenerative disorders. The present study assessed CR and its impact on cognitive abilities in spinocerebellar ataxia type 2 (SCA2), which is a rare cerebellar neurodegenerative disease. We investigated the existence of CR networks in terms of compensatory mechanisms and neural reserve driven by increased cerebello-cerebral functional connectivity. The CR of 12 SCA2 patients was assessed using the Cognitive Reserve Index Questionnaire (CRIq), which was developed for appraising life-span CR. Patients underwent several neuropsychological tests to evaluate cognitive functioning and a functional MRI examination. Network based statistics analysis was used to assess functional brain networks. The results revealed significant correlations of CRIq measures with cognitive domains and patterns of increased connectivity in specific cerebellar and cerebral regions, which likely indicated CR networks. This study showed that CR may influence disease-related cognitive deficits, and it was related to the effective use of specific cerebello-cerebral networks that reflect a CR biomarker.

In the past 10 years, the implementation of grassland ecological compensation policy has played an important role in the sustainable development of the pastoral economy. How much impact on herders will delineating the ecological conservation redline have? Such delineation is significant for the smooth implementation of the ecological conservation redline. Based on this, taking the three banner counties with a large area under the control area of the ecological redline of the Xilin Gol as examples, OLS and quantile regression were used to analyze the impact of a grassland ecological compensation policy on herdsmen’s income level, and the ordered Probit model was used to analyze the influencing factors of herdsmen’s satisfaction with the policy. The results show that: (1) grassland ecological compensation has a significant positive impact on low-income herders in ecological protection redline areas; (2) grassland ecological compensation, income and the implementation of current policy have a positive impact on the satisfaction of herders in the redline area; (3) herdsmen are highly satisfied with the grassland ecological compensation policy, but there is still a lot of room for improvement in the compensation policy after the redline is delineated. In this regard, we should increase compensation for areas with a high proportion of ecological conservation redlines, and explore ways to increase income from animal husbandry products. At the same time, we should strengthen the publicity of ecological protection redline policies and promote the timely disbursement of funds, reconstruct the grassland ecological compensation mechanism by strengthening policy incentives and hardening regulatory constraints, and effectively improve the policy efficiency of ecological protection redlines.

The growing supply–demand imbalance of idle rural homesteads threatens food security and eco-environmental sustainability. The construction of production relations centered on new—quality productive forces is crucial for resolving this dilemma and accelerating China’s high—quality development. Integrating planned behavior theory and rural migration framework, this study analyzes determinants of farmers’ homestead relinquishment intentions using survey data. Age, annual income, number of homesteads owned, and the purchase of a house in town all have a significant effect on farmers’ withdrawal homesteads. Upon withdrawing their homesteads, farmers take into account policies and regulations, compensation standards, livelihood security after withdrawal. Material needs and attachment to the countryside constitute two pivotal factors influencing farmers’ decisions to withdraw homesteads. Farmers who own more than two homesteads and have purchased a house in town favor long—term compensation, while tend to favor one—time compensation. In the process of homestead exit, a multi—agent, personalized, and comprehensive policy system should be established according to the actual needs of farmers. This research contributes theoretical insights for grain-producing regions’ land management innovation and offers a replicable model for global rural land consolidation practices.