Coordination Scheme Research Articles

Multi‐source PV‐battery DC microgrid operation mode and power allocation strategy based on two layer fuzzy controller

AbstractThe conventional DC bus signaling (DBS) coordination control strategy for islanded DC microgrids (IDCMGs) faces challenges in coordinating multiple distributed generators (DGs) and fails to effectively incorporate the state of charge (SOC) information of the energy storage system, reducing system flexibility. In this article, a two‐layer fuzzy control‐based coordination strategy is proposed for multi‐PV islanded DC microgrids. The first layer fuzzy logic controller (FLC) quantifies and selects the optimal system operating mode, adaptively adjusting the number of PV units operating in maximum power point tracking (MPPT) mode to manage system power surplus or deficit, thereby simplifying system design and enhancing flexibility. The second layer FLC adaptively adjusts the output of distributed energy sources based on SOC and current system conditions to better align the energy storage system's output with overall system operation, resulting in at least a 4% improvement in SOC level and effectively preventing overcharging or over‐discharging issues seen in traditional control. Additionally, for PV units operating in droop mode, the droop coefficient is recalculated based on their maximum generation capacity under changing external conditions, thereby achieving more efficient power distribution and preventing system instability caused by power exceeding the limits of individual PV units. Finally, the effectiveness of the proposed control strategy is validated through RT‐lab hardware‐in‐the‐loop (HIL) simulations.

Energy-Efficient Dynamic Enhanced Inter-Cell Interference Coordination Scheme Based on Deep Reinforcement Learning in H-CRAN

The proliferation of 5G networks has revolutionized wireless communication by delivering enhanced speeds, ultra-low latency, and widespread connectivity. However, in heterogeneous cloud radio access networks (H-CRAN), efficiently managing inter-cell interference while ensuring energy conservation remains a critical challenge. This paper presents a novel energy-efficient, dynamic enhanced inter-cell interference coordination (eICIC) scheme based on deep reinforcement learning (DRL). Unlike conventional approaches that focus primarily on optimizing parameters such as almost blank subframe (ABS) ratios and bias offsets (BOs), our work introduces the transmission power during ABS subframes (TPA) and the channel quality indicator (CQI) threshold of victim user equipments (CTV) into the optimization process. Additionally, this approach uniquely integrates energy consumption into the scheme, addressing both performance and sustainability concerns. By modeling key factors such as signal-to-interference-plus-noise ratio (SINR) and service rates, we introduce the concept of energy-utility efficiency to balance energy savings with quality of service (QoS). Simulation results demonstrate that the proposed scheme achieves up to 70% energy savings while enhancing QoS satisfaction, showcasing its potential to significantly improve the efficiency and sustainability of future 5G H-CRAN deployments.

Thunder Alone Does Not Defeat an Enemy: An Analysis of Airpower in Vietnam

Operation Rolling Thunder is among the most well-known aerial operations in the Vietnam War, if not all of military history. However, that recognition originates more from infamy than achievement. The massive employment of ordinances, manpower, capital and military logistics did not yield the results desired by the American top brass, instead, the war in Vietnam only intensified with mounting American casualties and growing anti-war sentiments. To be concise, it was a failure. This paper aims to analyze 1) how Operation Rolling Thunder was executed, 2) why it was conducted that way, and 3) what therein should be blamed for the disastrous results mentioned earlier. The objective of the paper is to provide relevant suggestions for the use of airpower based on the experiences of Operation Rolling Thunder. This paper dissects Operation Rolling Thunder by its context, execution, and efficacy to demonstrate the usefulness air power had in the war. The operation was poorly planned and done in almost all major aspects, and the results were similarly poor. Airpower failed to be an effective political tool in this case as it failed to bring the North Vietnamese government to the negotiating table. The research employs a qualitative historical analysis, drawing from established military doctrines, primary sources such as U.S. governmental documents, and secondary scholarly discussions. Findings indicate that the gradual escalation strategy, political mismanagement, and lack of coordination with ground forces were key factors contributing to the operation's failure. The study concludes by offering recommendations for the effective use of airpower in modern military campaigns, demonstrating that airpower must be deployed in concert with other military assets to achieve political objectives.

Electron-Lattice Synergistic Coordination for Boosting the Electro-Optic Response of the Crystal.

The electro-optic (E-O) response is fundamental where the refractive index of materials can be modulated by the external electric field. Up to now, E-O modulation has become a critical technology in photonics, quantum optics, modern communication, etc. However, the design of E-O crystals with broadband availabilities and large E-O effect is still challenging since the E-O response is contributed by both electrons and phonons. Here, an electron-lattice synergistic coordination strategy is proposed for boosting the E-O response, and with the langasite as the subject, a novel crystal La3Zr0.5Ga5Si0.5O14 (LZGS) is designed. By the rational introduction of the Zr4+ ion in the octahedral site, it is found that the E-O response can be obviously improved attributed to the active 4d orbitals of the Zr4+ ion and the optical phonons of the flexible (ZrO6) unit. This crystal also has advantages in transparency, laser damage threshold and E-O coefficient compared with the well-known E-O crystals. Moreover, broadband E-O modulation is also demonstrated in the lasers at wavelengths from 639 to 1991nm. These findings not only demonstrate an excellent E-O crystal for the development of modern devices in classical and quantum fields but also provide a design strategy for boosting the E-O response.

Coordination strategies to improve COVID-19 PCR laboratory testing scale up in Nepal: An analysis.

During the COVID-19 pandemic, Nepal rapidly expanded its PCR testing capacity, essential for effective outbreak response. However, many laboratories faced overwhelming test volumes, resulting in delays that may have hindered containment efforts. This study aims to determine whether these challenges stemmed from capacity limitations and/or imbalanced sample distribution due to inadequate coordination. In this retro-perspective simulation of SARS-CoV-2 testing in Nepal during 2021, we evaluate the impact of coordinated sample transfers on reducing laboratory stress and wait times during demand peaks. Our findings reveal that centralized coordination and strategic partnerships for sample transfers significantly enhance diagnostic network performance, even under high demand. These insights offer valuable guidance for policymakers on implementing effective coordination strategies to strengthen diagnostic networks for future pandemics.

Enhancing Resilience and Coordination in Sustainable Logistics Service Supply Chains Through Integrated Investment Contracts

Within the logistics service supply chain, where logistics service integrators and providers collaborate, the role of integrators in orchestrating resources and enhancing supply chain efficiency is pivotal. To motivate logistics service providers to invest in logistics capacity, thereby maintaining supply chain resilience and achieving coordination, a joint contract incorporating cost and benefit sharing is proposed in a novel Stackelberg game model. By analyzing the behavior of various decision-making models—centralized, coordinated, and decentralized—in supply chains, we find that the proposed Stackelberg game model effectively correlates higher investment levels with increased supply chain resilience. The coordination mechanism significantly improves both the level of resilience and the investment amount, leading to enhanced overall profitability. Sensitivity analysis reveals the impact of market pricing, demand stockout penalty costs, and substitute demand prices on these outcomes. This research contributes a new theoretical framework and practical insights into supply chain coordination and investment strategies.

Coordination strategy and contract design of platform supply chain for large-scale sports events with low carbon preference.

The organization of sports events, while generating economic benefits, inevitably imposes significant environmental pressures. Conducting green and low-carbon sports events have become a global consensus. In addressing the carbon emissions and benefit coordination issues on the production end of infrastructure construction for large-scale sports events, we considers the significant role of digital platforms in the industry's low-carbon transformation and upgrade, and innovatively incorporates platforms as decision-making entities and investigates the equilibrium strategies for low-carbon cooperation under three different power structures: one led by the sports events materials supplier, one by the materials distributor, and one by the integrated service platform. Additionally, it designs related cost-sharing contracts. The findings suggest that: centralized decision-making is more conducive to aligning the interests of various entities within the sports events platform supply chain. Different power structures have distinct impacts on overall supply chain profits and carbon emissions. Specifically, the supply chain achieves the highest overall profit under the domination of the integrated service platform, while the lowest level of carbon reduction occurs under the domination of the materials distributor. These results provide strategic insights for the low-carbon development of sports events and the coordinated cooperation within platform supply chain.

Ru Active Centers Incorporated on Ce‐MOFs as an Efficient Heterogeneous Catalyst for Oxidation of Alkylarenes to Carbonyls

AbstractIn recent years, the construction of the carbonyl group which can be extensively found in various important chemicals have attracted great interest of researchers. In this study, a strategy of coordination is employed to synthesize Ru‐UiO‐66‐NH2 (Ce) with uniformly dispersed Ru ions in UiO‐66‐NH2 (Ce) MOFs as an efficiently heterogenous catalyst for the catalytic oxidation of benzyl sp3 C─H bond to the carbonyl group in water. The characterized results indicate that the active Ru centers were successfully incorporated via the coordination with the amino group in UiO‐66‐NH2 (Ce) MOFs. This strategy could furnish more catalytic active sites to improve the catalytic performance of Ru‐UiO‐66‐NH2 (Ce). A series of alkylarenes could be efficiently oxidized to ketones with Ru‐UiO‐66‐NH2 (Ce) catalyst under mild conditions. Furthermore, the catalyst's recyclability demonstrated that its catalytic performance remained robust, with no significant loss in the catalytic activity observed after being recycled seven times.

Improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy

The flexible DC transmission project of renewable energy has become an inevitable development trend for large-scale renewable energy grid connection. Its two-terminal weak feed AC system is often composed of 100 % power electronic power equipment. The fault control strategy is used at both ends of the line to change the fault current characteristics, leading to a decrease in the performance of traditional differential protection. Based on analyzing the adaptability of current differential protection in the two-terminal weak feed AC system under traditional control strategy (TCS), this paper proposed an improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy. Firstly, the fault characteristics of the two terminal weak feed AC systems are analyzed. On this basis, the adaptability of differential protection under TCS is analyzed, and the quantization function that can quantify the operation performance of differential protection is given. Secondly, based on the problem of the traditional negative sequence control strategy, an improved control strategy is introduced and the operation performance of differential protection under the improved control strategy is studied. Finally, an improved differential protection scheme based on the change of current amplitude is proposed. Simulation results show that the proposed protection scheme can resist higher fault impedance(300 Ω) and noise interference(25 dB). In addition, the proposed differential protection scheme is suitable for the protection requirements of the two terminal weak feed AC systems in different scenarios and has higher sensitivity.

Coordination Strategy for Achieving Community Social Infrastructure Development Goals in Bhola, Bangladesh

This paper aims at identifying the Prospects for Sustainability in Community Social Infrastructure Development having regard to Coordination Mechanisms and Stakeholders: A Case of Bhola Bangladesh. Employing a qualitative research approach, the paper seeks to establish the issues, approaches, and achievements towards owning coordination in rural setting. Interviews, focus group discussions and document review adopting both open ended questionnaires and interviews were conducted with 20 purposively selected participants drawn from different fields similar to previous study. Therefore, this study established that though there is improvement in coordination at the Bhola level, problems like resource constrains, lack of technical know-how and communication barriers are still some of the issues that hinder the functioning of agencies there. Improvement in the coordination measures entailed the maintenance of an open forum, trust amongst the stakeholders, and the adoption of the structure that captured the needs of the locals. Moreover, it was also found that for infrastructure projects to have sustainable outcomes, the community has to be involved actively in the projects. This paper adds to the studies on multi-stakeholder partnership in community advancement and offers ideas concerning the issues of advancing rural, Ashley positioned, limited asset areas. The study therefore can contribute to enhancing the coordination strategies in other contexts with the inference that equal blend of formal and informal coordination mechanism coupled with active community participation plays critical role to enhance the development of infrastructure projects.

A graph-empowered agent-based simulation: Impacts of coordination schemes on critical infrastructures resilience

Critical infrastructure systems are governed by several sectors working together to maintain social, economic, and environmental well-being. Their cyber–physical interdependencies influence their performance and resilience to routine failures and extreme events. To balance investment and restoration decisions in the face of disruptive events, mostly centralized mathematical formulations and solutions were presented in the literature. However, not all physical and dynamic characteristics of infrastructure systems and their decision makers can be modeled via mathematical models. In this study, we take a different approach and utilize agent-based modeling to simulate city-scale interdependent infrastructure networks as a complex adaptive system. In specific, we design a flexible modular (object-oriented) simulation tool capable of capturing the dynamic behaviors of various networks. We first model each infrastructure as a weighted graph with relevant geospatial attributes. Decision makers for each infrastructure sector are represented by intelligent agents. We then define three information and coordination schemes among agents, including no communication, leader–follower, and decentralized coalitions. To show the applicability of the approach, we use publicly available interdependent water distribution and road networks for the City of Tampa, FL, which is prone to hurricanes. We simulate different magnitudes of physical, cyber, and cyber–physical failures, evaluate resource allocation decisions, made by agents under each coordination scheme, and quantify the aggregated resilience. The simulation platform will help municipalities in various cities to quantify the impact of their collective decision making and identify the best coordination structures when interdependencies are modeled in infrastructure systems.

Oxygen Evolution Enhancement of Oxalate-Based Nickel-Iron MOF through Bipyridine Coordinated Strategy.

The catalytic performance of oxalate-based Ni-Fe metal-organic frameworks (MOFs) in the oxygen evolution reaction (OER) was investigated via a coordination strategy. The bidentate chelating ligand 2,2'-bpy (2,2'-bipyridine), was utilized to improve the catalytic kinetics under ambient conditions. The results revealed that a MOF-to-MOF transformation including the formation of [M(2,2'-bpy)n]2/3+ (M = Ni/Fe, n = 1-3) could boost alkaline OER, giving an impressive ultralow overpotential of 220 mV at a current density of 10 mA/cm2 in a 1 M KOH solution, surpassing the performance of control group activity of oxalate-based Ni-Fe MOF. However, excessive addition of the ligand had a negative effect, leading to decreased activity. Further investigation revealed the double role of 2,2'-bpy: Both promote and suppress catalytic reactions. The catalytic mechanism was then discussed, highlighting the potential of secondary ligands to effectively fine-tune the catalytic behavior of these materials.

Nanoengineering of Phosphate/Phosphonate Drugs via Competitive Replacement with Metal‐Phenolic Networks to Overcome Breast Tumor with Lung and Bone Metastasis

AbstractPhosphate and phosphonate drugs are vital in building organisms, regulating physiological processes, and exhibiting diverse biological activities, including antiviral, antibacterial, antineoplastic, and enzyme‐inhibitory effects. However, their therapeutic potential is limited by the lack of advanced nanoengineering technologies. Herein, a competitive coordination strategy for nanoengineering phosphate/phosphonate drugs is introduced. By leveraging the difference in coordination capabilities between polyphenols and phosphates/phosphonates with metal ions, various phosphate/phosphonate‐based nanodrugs using metal‐phenolic networks (MPNs) as templates and phosphate/phosphonate drugs as competitive agents are constructed. The dynamic nature of these coordination bonds imparts stimuli‐responsiveness to the nanodrugs, allowing for targeted release and therapy. As a proof of concept, Fe3+ and galangin are used to form the MPN template, zoledronic acid and cGAMP as competitive agents, and DOX as the loaded drug to construct DOX@Fe‐galangin@Fe‐zoledronic acid‐cGAMP nanodrugs. The results demonstrate that, by triggering pyroptosis and activating the cGAS‐STING pathway, the nanodrugs exhibit potent cytotoxicity and accurate selectivity in eradicating orthotopic breast tumors, and activate an antitumor immune response against lung and bone metastases. Because the competitive coordination strategy is applicable to a variety of phosphate/phosphonate agents, it holds significant potential for enhancing the clinical efficacy of phosphate/phosphonate drugs and advancing nanodrug development for complex therapeutic applications.

Oriented and Continuous Phase Epitaxy Enabled by A Highly Dendrite‐Resistant Plane Toward Super‐High Areal Capacity Zinc Metal Batteries

AbstractUnstable Zn metal anodes with dendrites/side reactions are becoming the main obstacle to the practical application of zinc‐based aqueous batteries. Epitaxial growth has been considered to be an effective strategy for solving these issues, especially for inducing the (002) plane growth. Nonetheless, the (002)‐textured Zn is difficult to achieve highly stable Zn anode under high capacity resulting from its large lattice distortion. Herein, the Cu single atom anchored polymeric carbon nitride (Cu@PCN) is synthesized by a facile thermal polymerization method. Serving as multifunctional protective layer on Zn surface, the Cu@PCN can provide massive nucleation sites at a nano‐level and uniformize the electron distribution through coordination engineering. Optimizing the coordination structures of single Cu and N atoms within the carbon matrix enables a redistribution for electric field and regulates ion flux. More importantly, this coordination strategy with single atoms is first reported to customize oriented and continuous phase epitaxy along highly dendrite‐resistant Zn(101) plane by reducing (101) surface energy. This pattern of oriented dense deposition leads to stable and reversible Zn plating/stripping is achieved, which delivers an extended cycling life of 550 h at 10 A cm−2, 20 mAh cm−2. The practical full cell also displays stable performance for 1200 cycles.

Digital twin for advanced optimal coordination scheme of distance and Dual-Stage overcurrent relays

Integrating Distributed Generators (DGs), particularly renewable energy sources such as wind systems, into traditional power network presents significant protection coordination challenges. This study introduces a new optimal coordination scheme for distance and double-Stage Overcurrent (OCR) characteristics relays, utilizing digital twin technology. The proposed dual-stage of OCR protection to enhance the efficacy of the coordination between distance relays and OCRs. By employing advanced digital twin models and Hardware-in-the-Loop (HIL) testing, the proposed scheme aims to enhance fault management and relay coordination for microgrids. The scheme’s effectiveness is evaluated using a reference power network (CIGRE radial and mesh network) with and without wind systems under various fault types and locations. The study demonstrates substantial improvements over traditional and modern dynamic distance relays coordination approaches, including a reduction in maximum tripping time from 0.85 s to 0.19 s with the dual-stage scheme. Comparative analysis of digital simulation and physical twin relays further validates the accuracy and robustness of the proposed scheme.

Numerical Modeling of Two-Phase Fluid Filtration for Carbonate Reservoir in Two-Dimensional Formulation

This work considers the isothermal process of incompressible viscous fluid filtration in an oil-saturated, fractured-porous reservoir. A study of the pressure and water saturation distribution process is carried out for a case in which a production well is put into operation. For this problem, i.e., a mathematical model in a two-dimensional formulation, a numerical method and a parallel algorithm are proposed. The mathematical model of two-phase filtration is written in accordance with the classical laws of continuum mechanics and Darcy’s law and also includes a function of fluid exchange between low-permeability pores and high-permeability natural fractures within the framework of the Warren–Root model. The numerical solution is based on the finite-difference method and a splitting scheme of physical processes and spatial coordinates. For a split system with respect to piezoconductivity, an implicit finite-difference scheme with fixed saturations is constructed, and with respect to saturation transfer, explicit and implicit difference schemes are constructed. For parallel implementation of the developed numerical approach, a method based on geometric parallelism is selected. Testing of the developed method is performed using the example of calculating liquid mass transfer for a wide range of parameters. To verify the model, the obtained calculated pressure curves are compared with field data recorded by a deep-well measuring device. The results allow for estimation of the distribution of reservoir pressure and water saturation depending on the permeability of the fracture set and the pore part. The obtained results allow for monitoring of well operations, reducing unexpected accident risks and optimizing the development system in order to increase oil production in fractured-porous reservoirs. Computational experiments confirm the efficiency of the developed numerical algorithm and its parallel implementation.

Sensitivity of Cerebellar Reaching Ataxia to Kinematic and Dynamic Demands.

Individuals with cerebellar ataxia often face significant challenges in controlling reaching, especially when multijoint movements are involved. This study investigated the effects of kinematic and dynamic demands on reaching movements by individuals with cerebellar ataxia and healthy controls using a virtual reality task. Participants reached to target locations designed to elicit a range of coordination strategies between shoulder and elbow joint movements. Results showed that the cerebellar group exhibited greater trajectory curvature and variability in hand paths compared to controls, with pronounced deficits in the initial hand movement direction. Kinematic simulations indicated that early hand movement errors were sensitive to the required onset times and rates of joint movements and were most impaired when opposite direction joint movements were required (e.g., elbow extension with shoulder flexion). This highlights significant disruptions in motion planning and feedforward control in the cerebellar group. Dynamic analysis showed that cerebellar participants' movements were more impaired in reaching directions where interaction torques normally assist the desired elbow and shoulder movements, which required them to rely more on muscle torques to move. These reach directions were also those that required opposite direction joint movements. Overall, our data suggest that reaching deficits in cerebellar ataxia result from 1) the early-phase motion planning deficits that worsen with tight timing requirements and 2) the inability to compensate for interaction torques, particularly when they assist the intended movement.

Integrated market scheduling with flexibility options

This work presents a generic optimization framework using advanced mixed-integer programming techniques to integrate day-ahead and balancing markets with distributed energy resources such as storage, electric vehicles, demand response, and Transmission and Distribution System Operators' coordination schemes. The day-ahead model determines optimal initial energy scheduling, while the balancing model optimizes energy and reserve products for three market designs with varying Transmission and Distribution System Operators’ coordination. The framework is applied to the interconnected Greek-Bulgarian-Romanian power system, considering 2030 installed capacities.The model outputs illustrate market coupling scenarios among Romania, Bulgaria, and Greece, highlighting clear price signals and distributed energy resources flexibility. Results reveal the significance of a diverse energy mix for energy security and show that Transmission and Distribution System Operators’ coordination significantly influences ancillary service prices, with reductions of up to 80 % in certain scenarios. Net demand values determine electricity flow direction. Flexibility providers like storage can cover up to 100 % of the upward congestion management requirements and 11 % of upward balancing energy, helping smooth energy allocation from intermittent renewables. The impact of electric vehicle penetration on generation scheduling is minimal. The proposed model offers valuable insights for system operators, market participants, and policymakers, enabling them to provide accurate price signals and optimize resource allocation.The integrated day-ahead and balancing market models support efficient renewable energy integration, emissions reduction, enhanced grid stability, and investment in low-carbon technologies. This aligns with the United Nations Framework Convention on Climate Change goals, contributing to the development of sustainable and resilient energy systems.

Efficient Li+/Mg2+ separation by two-dimensional montmorillonite membrane with stable channel structure through ion exchange and metal–organic coordination strategy

Two-dimensional (2D) nanochannel membranes stacked by nanosheets are promising membrane separation materials. However, intrinsic swelling properties of 2D membrane have emerged as a significant challenge to establish stable nanochannels and achieve high separation performance. Inspired by the natural ion exchange property of montmorillonite (MMT), we constructed a two-dimensional MMT membrane with robust nanochannels by exchanging Fe3+ into interlayer of the membrane, and further achieved efficient separation of Li+/Mg2+ through coordination manipulation of tannic acid (TA) and Fe3+. Swelling was dramatically prevented by strong interlayer interaction between exchanged Fe3+ and nanosheets resulting in a 32-fold increase in anti-swelling properties. Furthermore, experiments and simulations revealed that TA could rapidly chelate with Fe3+ to form a dense hydrophilic functional layer on the membrane interface, which endowed MMT membranes with enhanced mechanical strength, cation transport and recognition, as well as anti-fouling properties. Consequently, the resulting MMT membranes showed the Li+/Mg2+ selectivity as high as 9.98 with a fast Li+ permeation rate (0.108 mol m-2 h-1), which exceeded most of the previously reported membranes. This study proposed a novel strategy to diminish the trade-off effect among stability, ion flux, and selectivity of membranes, and inspired the development of next-generation ion selective separation membranes.

Breaking Symmetry for SHG Response: Lanthanide Acetate Crystals via Water Molecule Regulation Strategy.

In the field of nonlinear optical (NLO) materials research, the design and synthesis of novel materials are crucial for advancing modern scientific and technological development. This study employs an innovative coordination strategy, building upon the existing structure of [Ln2(CH3COO)6(H2O)4]·4H2O (Ln = Tb, Sm), to successfully synthesize a series of acetate rare-earth metal compounds [Ln2(CH3COO)6(H2O)]n [Ln = Tb(1), Er(2), Y(3)] by regulating the number of water molecules. This approach achieved a structural transition from centrosymmetric (CS) to noncentrosymmetric (NCS), endowing these compounds with significant nonlinear optical responses. We discovered that reducing the coordinated water molecules and introducing acetate as a bidentate ligand is an effective method for modulating crystal structure and realizing NLO performance. This finding not only deepens the understanding of the structure of acetate salts but also provides important theoretical and experimental support for the development of materials with potential NLO propeties.