Systematic Control Research Articles

Power Regulation of a Three-Phase L-Filtered Grid-Connected Inverter Considering Uncertain Grid Impedance Using Robust Control

Uncertain grid impedance is often common in power distribution networks; therefore, it is crucial to design an efficient controller in this situation. An issue that frequently occurs is the problem of unpredictable grid impedance, which can cause voltage fluctuations, power quality problems, and potential damage to equipment. This work provides a systematic control strategy to tackle these issues by supplying well-regulated power from a DC source to an AC power grid. A linear matrix inequality (LMI)-based robust optimal control is proposed in this paper to provide stability to the inverter system without offset error at the output side. The convergence time to steady state is minimized by solving the LMI problem to maximize the eigen value of the closed-loop system with the inclusion of the uncertainty of the filter parameter and grid impedance. Furthermore, the uncertainties in this study include the potential variation of values for the filters and the grid's impedance. These uncertainties occur because the grid impedance can fluctuate fast in the event of a fault or termination of a transmission line, while the filter's impedance can also be affected by changes in operating temperature. The simulation study of this proposed control includes a comparison between wide and narrow uncertainty ranges, as well as a performance comparison under uncertain parameters. Furthermore, this approach exhibits a lower power ripple in comparison to existing PI control method.

Systematic Control Design for Adaptive Rejection of Narrow-Band Disturbances Based on a Novel Resonant Generalized Extended State Observer

In this paper, the adaptive rejection of multiple narrow-band disturbances with time-varying frequencies is investigated. A systematic control approach based on a resonant generalized extended state observer (RGESO) is proposed. The frequency response of the RGESO is shaped into a desired form to reject the total disturbance, including the wide-band uncertainties and the narrow-band disturbances. The state-space realization of the RGESO is also provided to estimate both the states and the total disturbance. To handle the time-varying frequencies of the narrow-band disturbances, a direct frequency estimation approach based on the Levenberg–Marquardt method and an online supervision strategy is presented to improve convergence and reliability, and the estimations are then used to adapt the RGESO parameters. Parameter tuning and stability robustness analysis methods are also developed for the proposed scheme to facilitate its application. Finally, extensive simulations are conducted to demonstrate the effectiveness of our method.

Nanocrystalline sodium mordenite as an efficient low-concentration CO2 adsorbent

Systematic control of the crystal size and morphology of zeolites to enhance their CO2 adsorption performance is of great importance from both environmental and economic perspectives. Here we report the seeded synthesis of sodium mordenite (Na-MOR) with a Si/Al ratio of 4.9 and an average crystal length and width of 70 and 40 nm, respectively, using γ-aminobutyric acid as a crystal growth inhibitor in the absence of any organic structure-directing agent (OSDA). This nanozeolite shows an unprecedented CO2 capacity of 1.58 mmol g−1 under dynamic direct air capture (DAC) conditions at 25 °C, which is approximately 40 % greater than the value (1.15 mmol g−1) of the best zeolite adsorbent (an unidentified OSDA-directed Na-MOR (Si/Al = 5.0) zeolite with Na+ enrichment in 8-ring side pockets), mainly due to its nanocrystalline nature. It has also been characterized by much faster CO2 adsorption kinetics (ca. 5 vs. 50 min equilibration time) compared to a commercial Na-MOR zeolite with Si/Al = 5.0. Our study paves the way for developing a more efficient zeolite-based DAC adsorbent.

Characteristic analysis and mitigation strategy for SSCI in series-compensated DFIG-based wind farm controlled by a virtual synchronous generator

The proliferation of virtual synchronous generator (VSG) technology within series-compensated double-fed induction generator (DFIG)-based wind farms is substantially hampered by the attendant risk of subsynchronous control interaction (SSCI), resulting in a significant research deficiency on systematic control interaction analysis and the development of mitigation strategies. The paper proposes an advanced active disturbance rejection control (ADRC) framework, incorporating real-time compensation mechanisms to mitigate the inadequate suppression efficacy attributable to the VSG's diminished output impedance. Initially, the mathematical expression for the VSG output impedance is rigorously deduced, and the positive damping attributes of the VSG in relation to SSCI are elucidated from the perspective of underlying mechanistic principles. Subsequently, the suppressive mechanism of SSCI by the ADRC is revealed in the context of VSG involvement, and the consequent augmentation of SSCI attributed to PI control is systematically derived. In immediate succession, the quanta of oscillation and inductive cross-coupling are encapsulated as the system's aggregate disturbance, thereby streamlining the ADRC to its primary order configuration, permitting the utilization of an extended state observer (ESO) for the dynamic estimation of said disturbance. Furthermore, a fractional-order filter function is instituted to engineer an augmented ESO, which refines the output voltage of the grid-side converter. Concurrently, a meticulous discourse on the rectification strategy for the proposed ESO parameters and its stability ensues. Ultimately, the efficacy of the mechanism analysis, alongside the robustness of the proffered control strategy for SSCI mitigation under diverse perturbation conditions, is corroborated via impedance evaluation and time-domain simulation.

Integration of Machine Learning Algorithms with Cloud Computing for Real-Time Data Analysis

As part of this study though, real-time data analysis is examined by exploring the combination of machine learning algorithms with cloud computing. It does so by defining optimization problems and solutions, as well as outlining optimization goals and directions for development. The efficiency of real time data processing ability is also amplified with the use of an amalgamation of machine learning and cloud computing though traditional systems are often associated with high failure rates and high costs of maintenance. Enhanced indexing, systematic control of information storage and retrieval, query optimization are the main benefits obtainable from this. This is because despite the challenges such as limited resources, integration has never been a problem even with challenges of data privacy. Peculiar trends such as Explainable AI, Automated ML, and Continuous Intelligence present the ability to substantially enhance operational proficiency and decision-making.

Impact of bull age, sperm processing, and microclimatic conditions on the viability and DNA integrity of cryopreserved bovine sperm.

Context Seasonal microclimatic fluctuations can cause changes in sperm quality even in dairy bulls bred under temperate climate. These changes can vary between sires of different age and affect sperm freezability. Aims We aimed to evaluate the modulating effect of bull age and equilibration time before freezing on the seasonal pattern of sperm viability and DNA integrity post-thaw. Methods In the frame of systematic sperm quality control, we assessed the integrity of sperm plasma membrane and acrosome (PMAI) in 15,496 cryopreserved bovine batches, and the percentage of sperm with high DNA fragmentation index (%DFI) after 0h and 3h incubation at 38°C post-thaw (3h) in 3422 batches. Semen was equilibrated for 24h before freezing if collected on Monday or Wednesday and 72h if produced on Friday. We investigated the effect of season, bull age, equilibration, and temperature-humidity index (THI) on the day of semen collection on sperm traits using mixed-effects linear models. Key results PMAI and %DFI (0h and 3h) deteriorated with increasing THI. The effect of THI on %DFI was detected with a 30-day time lag. Seasonal fluctuations of sperm quality were similar between young, mature, and older sires. Prolonged equilibration did not affect PMAI but was linked to elevated %DFI (3h) in summer. Conclusions Extending equilibration from 24 to 72h is compatible with commercial standards of bovine sperm quality post-thaw; however, it could interfere with the seasonal pattern of the latter. Implications Systematic monitoring of bovine sperm quality enables the prompt detection of stress factors related to microclimate and semen processing.

Systematic Controller Design for Inverter-Based Microgrids With Certified Large-Signal Stability and Domain of Attraction

Systematic Controller Design for Inverter-Based Microgrids With Certified Large-Signal Stability and Domain of Attraction

Lateral Heterostructure Formed by Highly Thermally Conductive Fluorinated Graphene for Efficient Device Thermal Management.

The continued miniaturization of chips demands highly thermally conductive materials and effective thermal management strategies. Particularly, the high-field transport of the devices built with 2D materials is limited by self-heating. Here a systematic control of heat flow in single-side fluorinated graphene (FG) with varying degrees of fluorination is reported, revealing a superior room-temperature thermal conductivity as high as 128W m-1 K-1. Monolayer graphene/FG lateral heterostructures with seamless junctions are approached for device fabrication. Efficient in-plane heat removal paths from graphene channel to side FG are created, contributing significant reduction of the channel peak temperature and improvement in the current-carrying capability and power density. Molecular dynamics simulations indicate that the interfacial thermal conductance of the heterostructure is facilitated by the high degree of overlap in the phonon vibrational spectra. The findings offer novel design insights for efficient heat dissipation in micro- and nanoelectronic devices.

ClosedLoop Control of Pulse-Density-Modulated Wireless Power Transfer with Fast MEPT

Efficient wireless power transfer (WPT) requires closedloop control to perform maximum efficiency point tracking (MEPT) against the dynamic changes of operating conditions. In this paper, we took the latest deltasigma pulse-density-modulated (PDM) WPT system as the plant and presented a systematic control design procedure. The WPT system was modeled by the reducedorder dynamic phasor method and further decoupled under the tuned condition. It was identified that the coupled resonators behave like a secondorder system, and its natural frequency is much lower than the resonant frequency. This was considered in the closedloop design to derive a suitable loop gain and ensure stability. The nonlinearity caused by the dualside PDM control is limited to a small inner loop so that the entire loop is linear and simple. Experimental results showed that the closedloop voltage regulation and MEPT took only about 10 ms after load stepping. The system DC output voltage was always tightly regulated, and the steadystate efficiency was very close to the theoretical maximum value under different coupling conditions.

Meta-Analysis of Optical Surrogates for the Characterization of Dissolved Organic Matter.

Optical surrogates, derived from absorbance and fluorescence spectra, are widely used to infer dissolved organic matter (DOM) composition (molecular weight, aromaticity) and genesis (autochthonous vs allochthonous). Despite the broad adoption of optical surrogates, several limitations exist, such as context- and sample-specific factors. These limitations create uncertainty about how compositional interpretations based on optical surrogates are generalized across contexts, specifically if there is duplicative or contradictory information in those interpretations. To explore these limitations, we performed a meta-analysis of optical surrogates for DOM from diverse sources, both from natural systems and after water treatment processes (n = 762). Prior to analysis, data were screened using a newly developed, standardized methodology that applies systematic quality control criteria before reporting surrogates. There was substantial overlap in surrogate values from natural and treated samples, suggesting that the gradients governing the surrogate variability can be generated in both contexts. This overlap provides justification for using optical surrogates originally developed in the context of natural systems to describe DOM changes in engineered systems, although the interpretations may change. Absorbance-based surrogates that describe the amount of spectral tailing (e.g., E2:E3 and S275-295) had a high frequency of strong correlations with one another but not to specific absorbance (SUVA254) or absorbance slope ratio (SR). The fluorescence index (FI) and biological index (β/α) were strongly correlated with one another and to the peak emission wavelength but not to the humification index (HIX). Although SUVA254 and FI have both been correlated to DOM aromaticity in prior research, there was a lack of reciprocity between these optical surrogates across this data set. Additionally, there were patterns of deviations in the wastewater subset, suggesting that effluent organic matter may not follow conventional interpretations, urging caution in the use of optical surrogates to track DOM in water reuse applications. Finally, the meta-analysis highlights that three aspects should be captured when optical spectra are used for DOM interpretation: specific absorbance, absorbance tailing, and the extent of red-shifted fluorescence. We recommend that SUVA254, E2:E3, and FI or β/α be prioritized in future DOM studies to capture these aspects, respectively.

ПРОДУКТИВНЫЕ ВИДЫ РЕЧЕВОЙ ДЕЯТЕЛЬНОСТИ НА УРОКАХ АНГЛИЙСКОГО ЯЗЫКА

Productive Types of Speech Activity at the English Lessons Summary For many centuries, reading as a productive type of speech activity has been one of the most important means of cognition. Reading in the history of mankind arose later than oral speech and on its basis. It has become an autonomous means of communication and knowledge. Complex integrated reading comprehension skill involves active mental activity of a person, including imagination, emotions, existing experienced knowledge. The active role of the reader with his unique individuality contributes to the reconstruction of the meaning of the content of what is being read, determines personal interpretation. Key words: motivation, systematic control, interactive approach, communicative situation, productive

Distinguishing the intrinsic differences of Cynomorium songaricum from different origins using chemical fingerprinting combined with chemometric methods

Cynomorium songaricum is a commonly used medicinal and culinary plant renowned for its effects in tonifying kidney yang, as well as nourishing essence and blood. Consequently, it has garnered considerable attention within the fields of pharmacology and chemistry. However, given the distinct geographical distribution of C. songaricum resources, establishing an accurate analytical method to differentiate its origin becomes indispensable in ensuring its quality and efficacy. In this study, high-performance liquid chromatography (HPLC) was utilized to obtain comprehensive information on the chemical composition of C. songaricum samples from various regions and establish HPLC fingerprints. Through chemometrics analysis, essential chemical markers for classifying them were successfully identified. Additionally, the Kruskal–Wallis rank sum test was employed to evaluate differences in the content of intrinsic constituents of C. songaricum from different origins. The results demonstrated that C. songaricum samples from Neimenggu, Gansu, and Xinjiang could be accurately classified, highlighting the significance of chemical markers in assessing the quality of C. songaricum. This study provides a scientific basis for systematic quality control of Chinese herbal medicines, thereby contributing to advancements in the Chinese medicine industry.

Revolutionizing flexible Electronics: Integrating liquid metal DIW 3D printing by bimolecular interpenetrating network

Ultra-flexible liquid metal (LM) composites have significant potential in various applications, including soft robotics, wearable electronics, and human–machine interactions. This burgeoning field necessitates mass production at a critical scale alongside highly accurate and fully automated technology. In this study, a direct ink-writing (DIW) 3D all-printing strategy was developed, integrating cellulose nanofibrils (CNF), water-based polyurethane (WPU), and LM to fabricate high-performance LM-based electronic films, circuits, and diverse 2D or 3D structures. The stable ternary interface system was investigated, and bimolecular interpenetrating network system of CNF/WPU significantly enhanced the flexibility, reducing LM damage, mitigation, and leakage. Moreover, the systematic control of the DIW all-printing process facilitated high-resolution and excellent printability. The super-flexibility and precise electrical conductivity were demonstrated by investigating bending deformation and recyclable electrical signals. Electronics based on ultra-flexible LM, with a high LM content (78.0%), exhibited an accurate electrical response to bending deformation, extraordinary flexibility, and recyclable durability (up to 500 cycles). Notably, the all-printed system facilitates the complete automation, complex structuring, and precise moulding of various appliances. DIW 3D all-printing of LM has the potential to create complex conductive architectures for programmable and multi-material LM-based electronics, meeting high-precision, large-scale, and automated production requirements.

Hospitalisations sans consentement : repères historiques et contemporains de l’intervention judiciaire dans le contrôle des mesures

ObjectivesThe question of judicial control emerged with the debates surrounding the law of 30 June 1838 instituting psychiatric hospitalization. However, it was systematically rejected until the law of 5 July 2011. This article examines the conditions under which such control was introduced. MethodThe aim is to analyze the debates surrounding the protection of the rights of mental patients hospitalized under judicial control during the proposed reforms to compulsory hospitalization. The reasons for the exclusion of judicial control from the 1838 and 1990 legislation will first be examined, before looking at the conditions leading to judicial review in 2011. ResultsThe introduction of systematic judicial control appears to be the result of the mobilization of patients’ associations, who brought the Question Prioritaire de Constitutionnalité (QPC) before the courts. This ability to use the law reflects a more developed legal knowledge, due to the legal route taken to assert their claims. This method of imposing reform bypasses the usual channels for reform. DiscussionThe reform has therefore led to the decision to unify litigation and to a systematic hearing by the juge des libertés et de la détention (JLD) for any patient hospitalized without consent. ConclusionThe use of the QPC as a strategy for imposing reforms in psychiatry has flourished in the years since the reform, in particular to question the legality of other psychiatric practices. However, the ability of the law to prevent these decisions from being arbitrary needs to be questioned.

Engineering Ultrathin Alloy Shell in Au@AuPd Core‐Shell Nanoparticles for Efficient Plasmon‐Driven Photocatalysis

AbstractBimetallic core‐shell nanoparticles (NPs) possessing a synergetic coupling of plasmonic and catalytic metals have emerged as promising prototypes for efficient plasmon‐driven photocatalysis. Here, Au@AuPd core‐shell NPs composed of Au core NP and ultrathin AuPd shell are introduced to acquire improved light utilization efficiency in photocatalytic selective oxidation. With systematical control of the composition of the ultrathin alloy shell, it reveals that the Au@AuPd core‐shell NPs with 10 at% Pd (in the single‐atom alloy regime) is an effective nanostructure capable of maximizing the quantum yield of plasmon‐induced light absorption and optimizing the surface electronic structure for catalytic reactions. This controlled system provides new insights into shell engineering for enhancing photocatalytic performance via the regulation of energy funneling processes in core‐shell nanocatalysts.

RISK ASSESSMENT FOR THE DEVELOPMENT OF THE EXEMPLIFIED TERRITORIES

The paper explores the risks associated with exempted and liberated territories that were previously used for certain industrial, commercial, agricultural or other activities. Such territories were captured or used by military forces during the war and then liberated or abandoned and left unattended, or were disturbed by natural disasters, man-made accidents, etc. The aim of the article is to analyze the possibility of their further use and rehabilitation. The following indicators of risk sources can be identified in such areas: presence of explosive objects; level of soil and water contamination; presence of chemical, biological or radiation contamination; degree of damage to infrastructure and building structures; risk of dangerous situations and accidents; impact on the health and safety of the local population; possibility of spreading infectious diseases; presence of unexploded or uncontrolled explosive materials; risk of re-invasion by enemy forces; potential environmental damage; and potential environmental impact. Based on the analysis of these indicators, they were summarized and grouped into six main risk indicators: demining of territories; efficiency of demining and disposal of remnants of military equipment, mines, etc.; safety and efficiency of demining and disposal technologies; degree of contamination of the demined territories after demining and disposal; level of safety assessment of the population living in these territories; return of vital infrastructure. An expert assessment methodology was applied, which includes an analysis of the severity of the consequences and the likelihood of their occurrence. The risks were ranked using the method of pairwise comparisons. The results of the study can be used to develop strategies for the further use and rehabilitation of the affected areas. The results of the study indicate the need for systematic monitoring and control of the exempted and liberated territories in order to prevent possible environmental and socio-economic problems. To ensure sustainable development and conservation of natural resources, due attention should be paid to the issues of environmental safety and rehabilitation of these territories. Further research in this area will allow developing more effective strategies for the use and rehabilitation of exempted areas, taking into account current environmental and socio-economic challenges.

Programming sp3 Quantum Defects along Carbon Nanotubes with Halogenated DNA.

Atomic defect color centers in solid-state systems hold immense potential to advance various quantum technologies. However, the fabrication of high-quality, densely packed defects presents a significant challenge. Herein we introduce a DNA-programmable photochemical approach for creating organic color-center quantum defects on semiconducting single-walled carbon nanotubes (SWCNTs). Key to this precision defect chemistry is the strategic substitution of thymine with halogenated uracil in DNA strands that are orderly wrapped around the nanotube. Photochemical activation of the reactive uracil initiates the formation of sp3 defects along the nanotube as deep exciton traps, with a pronounced photoluminescence shift from the nanotube band gap emission (by 191 meV for (6,5)-SWCNTs). Furthermore, by altering the DNA spacers, we achieve systematic control over the defect placements along the nanotube. This method, bridging advanced molecular chemistry with quantum materials science, marks a crucial step in crafting quantum defects for critical applications in quantum information science, imaging, and sensing.

The Effect of Global Spread, Epidemiology, and Control Strategies on the Evolution of the GI-19 Lineage of Infectious Bronchitis Virus.

The GI-19 lineage of infectious bronchitis virus (IBV) has emerged as one of the most impactful, particularly in the "Old World". Originating in China several decades ago, it has consistently spread and evolved, often forming independent clades in various areas and countries, each with distinct production systems and control strategies. This study leverages this scenario to explore how different environments may influence virus evolution. Through the analysis of the complete S1 sequence, four datasets were identified, comprising strains of monophyletic clades circulating in different continents or countries (e.g., Asia vs. Europe and China vs. Thailand), indicative of single introduction events and independent evolution. The population dynamics and evolutionary rate variation over time, as well as the presence and intensity of selective pressures, were estimated and compared across these datasets. Since the lineage origin (approximately in the mid-20th century), a more persistent and stable viral population was estimated in Asia and China, while in Europe and Thailand, a sharp increase following the introduction (i.e., 2005 and 2007, respectively) of GI-19 was observed, succeeded by a rapid decline. Although a greater number of sites on the S1 subunit were under diversifying selection in the Asian and Chinese datasets, more focused and stronger pressures were evident in both the European (positions 2, 52, 54, 222, and 379 and Thai (i.e., positions 10, 12, 32, 56, 62, 64, 65, 78, 95, 96, 119, 128, 140, 182, 292, 304, 320, and 323) strains, likely reflecting a more intense and uniform application of vaccines in these regions. This evidence, along with the analysis of control strategies implemented in different areas, suggests a strong link between effective, systematic vaccine implementation and infection control. However, while the overall evolutionary rate was estimated at approximately 10-3 to 10-4, a significant inverse correlation was found between viral population size and the rate of viral evolution over time. Therefore, despite the stronger selective pressure imposed by vaccination, effectively constraining the former through adequate control strategies can efficiently prevent viral evolution and the emergence of vaccine-escaping variants.

Strategic Oversight and Quality Validation in Spice Production Enhancement

This study examines the effectiveness of a comprehensive control management and quality control system in the seasoning production process, focusing specifically on a menu-specific seasoning variant (MSS). The methodology encompassed various stages including material acceptance, sieving, mixing, and final packaging, integrated with stringent control measures such as equipment and facility cleaning, material separation, and machine maintenance. Quality control tests conducted included sodium chloride content, pH analysis, seal strength, and bubble tests. Results indicate that these systematic processes significantly enhance product quality by ensuring compliance with predefined quality standards. The implications of this study suggest that rigorous process oversight and detailed quality assessments can markedly improve the reliability and safety of food seasoning products, providing a framework for industry-wide best practices. Highlights: Process Management: Systematic control measures, including equipment and facility cleaning, ensure a contamination-free production environment. Quality Control: Rigorous testing, including sodium chloride content and pH analysis, guarantees that the products meet established quality and safety standards. Product Compliance: Implementation of advanced control and quality assurance protocols ensures that products consistently comply with industry standards. Keywords: Instant Seasoning, Quality Control, Safety Standards

Tunable Neuromorphic Switching Dynamics via Porosity Control in Mesoporous Silica Diffusive Memristors.

In response to the growing need for efficient processing of temporal information, neuromorphic computing systems are placing increased emphasis on the switching dynamics of memristors. While the switching dynamics can be regulated by the properties of input signals, the ability of controlling it via electrolyte properties of a memristor is essential to further enrich the switching states and improve data processing capability. This study presents the synthesis of mesoporous silica (mSiO2) films using a sol-gel process, which enables the creation of films with controllable porosities. These films can serve as electrolyte layers in the diffusive memristors and lead to tunable neuromorphic switching dynamics. The mSiO2 memristors demonstrate short-term plasticity, which is essential for temporal signal processing. As porosity increases, discernible changes in operating currents, facilitation ratios, and relaxation times are observed. The underlying mechanism of such systematic control was investigated and attributed to the modulation of hydrogen-bonded networks within the porous structure of the silica layer, which significantly influences both anodic oxidation and ion migration processes during switching events. The result of this work presents mesoporous silica as a unique platform for precise control of neuromorphic switching dynamics in diffusive memristors.