Inter-cluster Coordination Research Articles

Regional photovoltaic grid power generation output prediction based on SVM and autoencoder

Photovoltaic power generation, which is an important component of clean energy, has been widely used around the world. However, the predictability of photovoltaic power generation systems has always been a challenge because it is affected by meteorological conditions and other external factors. Therefore, accurate photovoltaic power generation output prediction is crucial for the stability and reliability of the power system. This work aims to use two advanced machine learning technologies, supporting vector machine (SVM), and autoencoder (Autoencoder), to improve the prediction performance of regional photovoltaic grid power generation output. First, this article introduces the autoencoder and SVM network, and then we use the SVM algorithm to analyze and model these data. By using SVM, we can build a highly accurate photovoltaic power generation output prediction model that can predict on different time scales, from hourly level to daily level. Next, the principle and working mechanism of the support vector machine will be introduced in detail, and its advantages in processing complex data and high-dimensional features will be explained. Then, this article will use the grid search method to optimize the support vector machine model. A new cluster performance index based on electrical distance and regional voltage regulation capability is proposed, which divides the distribution network into multiple clusters. The voltage control strategy combines cluster autonomous optimization of time scales and distributed inter-cluster coordination optimization. Then we select evaluation indicators to evaluate the obtained model. The results show that the model can predict power generation output and provide a reference for making point arrangements. In terms of model building, this article will explain how to select appropriate features and parameters and use the collected data to train the SVM model. We also perform a detailed evaluation and analysis of the model’s performance. We use a variety of evaluation metrics to measure model accuracy and stability. Experimental results show that the SVM and autoencoder hybrid model have higher prediction accuracy and better generalization performance than traditional methods.

Research on control strategy of distributed photovoltaic cluster based on improved particle swarm-gray wolf coupling algorithm

Conducting research on cluster control strategies for distributed photovoltaic systems to address voltage fluctuations and reverse power flow caused by large-scale distributed photovoltaic integration is crucial foundational work in establishing a new power system and ensuring its safe and stable operation. Based on the division of distributed photovoltaic cluster, this paper takes distributed photovoltaic cluster as the intermediate layer of control, and researches the two-layer control strategy of inter-cluster coordination and intra-cluster autonomy. The inter-cluster coordination strategy is located at the upper layer, and this strategy based on the power grid structure of the controlled area, comprehensively considering the observability, controllability, degree and betweenness centrality of each node, the latter two characterize the spatial location of the nodes. The dominant nodes of each cluster are selected by the above multiple indicators. The multi-objective inter-cluster coordination control model respectively focusing on the minimum voltage deviation of the dominant node or the minimum network loss of the system is constructed according to whether the voltage of the dominant node crosses the limit or not, and the improved particle swarm-gray wolf coupling algorithm (PSO-GWO) is used to generate the output indicators of each cluster. The intra-cluster autonomy strategy is at the lower layer. In the shortage of adjustable PV resources connected to the dominant node, the intra-cluster autonomy strategy adopting the control sequence of dominant node-downstream node-upstream node to distribute the output indicators of inter-cluster coordination within the cluster; In addition, in view of the situation that the cluster cannot receive the output indicators due to communication failure, The intra-cluster autonomy control model is constructed with the goal of minimum voltage deviation and minimum network loss of the dominant node in the cluster. The distributed photovoltaic inter-cluster coordination + intra-cluster autonomy two-layer regulation strategy is used to simulate the improved IEEE33-nodes system under multiple scenarios. The results show that the proposed control strategy can effectively solve the voltage overlimit, power flow back and other problems, and play an important role in ensuring the safe and economic operation of the system.

Can intercluster coordination mediate the relationship between supply chain flexibility and humanitarian supply chain performance?

PurposeThe occurrence of disaster and crisis is increasing. They are complex as well as challenging for humanitarian organizations (HOs) and societies involved in disaster relief operations. This study examined the nexus between supply chain flexibility (SCF) and humanitarian supply chain performance (HSCP) among HOs with empirical evidence from HOs in Ghana.Design/methodology/approachThe study employed the quantitative method to explore the interdependencies among the variables. In congruence with this, the study employed the purposive and convenience sampling technique to obtain information from 168 respondents. The analysis was done using SPSS version 23 and Smart PLS version 3.FindingsThe outcome indicates that intercluster coordination (ICC) plays a significant mediating role between SCF and HSCP.Practical implicationsThe outcome of the study indicates that a closer and stronger relationship ensures proper channel use among the HOs. This will improve the performance of the supply chain of HOs and their ability to deal with supply chain uncertainties.Originality/valueThe discovery of this study provides empirical support to the resource-based view theory. Thus, practitioners in the humanitarian setting give priority to factors that could enhance flexibility in their supply chain as well as implement coordination strategies to achieve a responsive humanitarian supply chain (HSC) system in the quest to minimize the outcome of disasters.

Coordination at the 10-year mark of the JHLSCM–from global response to local preparedness

PurposeAt the inception of the Journal of Humanitarian Logistics and Supply Chain Management (JHLSCM), logistics coordination was identified as important, both in practice and research, but few studies on the topic had been published. Ten years later, many, if not most, papers in the journal mention the topic. So the picture has changed, but to what extent? This paper discusses how coordination research has followed humanitarian logistics practice and vice versa.Design/methodology/approachThe point of departure in the present article is the most salient topic from the study’s original papers (Jahre et al., 2009; Jahre and Jensen, 2010). The authors discuss how these topics have developed in research and practice. A recent literature review (Grange et al., 2020) enables us to pick relevant papers from JHLSCM and supplement them with more recent ones. The authors complement this approach with updated data on the cluster system, particularly the logistics cluster, to add insights from the empirical domain.FindingsIn practice, the cluster concept has developed from coordination within clusters in response to the inclusion of inter-cluster coordination in preparedness, and more recently a focus on localized preparedness. However, JHLSCM research does not appear to have kept pace, with a few notable exceptions. The majority of its papers still focus on response. To the extent that preparedness is covered, it is primarily done so at the global level.Originality/valueThe authors use a framework to discuss humanitarian logistics coordination research and identify important gaps. Based on developments in practice, the study’s key contribution is a revised model with suggestions for further research.

Adaptive variable-size virtual clustering for control channel assignment in dynamic access networks: Design and simulations

Cognitive Radio (CR) technology was introduced to effectively exploit the under-utilization portions of the licensed spectrum. A primary challenge in enabling CR networking is how to coordinate the CR communications, in which CR users need to exchange their control information before data exchange can take place. Providing a reliable coordination mechanism in CR networks (CRNs) is not an easy task because of the dynamic nature of primary radio (PR) activities and the heterogeneity of both spectrum availability and CR users’ distribution. In this paper, we propose a dynamic-size clustering with CSMA/CA-based algorithm to overcome the challenge of achieving reliable coordination in CR networks (CRNs). CR users in our scheme are organized into dynamic size clusters and cooperate in selecting common control channels (CCCs) and use them for cluster coordination. The proposed scheme called Dynamic-hop virtual clustering distributed coordination (DH-VCDC). This scheme provides a dynamic-hop virtual clustering based on the traffic condition of both PR and CR users while achieving a minimum number of common available data channels per cluster, in which a better trade-off between the number of common idle channels per cluster and the cluster size is achieved. DH-VCDC scheme exploits the advantages of using Multi-packet Multi-channel Discontinuous Orthogonal Division Multiplexing (DOFDM) to reduce neighbor discovery time, allow CR users to have several cluster memberships, select multiple CCCs and simplify the inter-cluster coordination. CR users in our scheme are grouped to form virtual clusters each contains at least 2 CCCs (primary and backup CCCs). Three modes of DH-VCDC are presented: one-, two- and three-hop modes. Each CR must continuously monitor both PR and CR traffic loads and accordingly chooses the appropriate DH-VCDC mode. The performance of DH-VCDC is compared with reference schemes, in which significant performance improvement is reported.

Enhancing service delivery in humanitarian relief chains: the role of relational capital

PurposeThe study examined the influence of relational capital on inter-cluster coordination and service delivery of humanitarian organisations; the mediating and moderating role of inter-cluster coordination on the relationship between relational capital and service delivery.Design/methodology/approachData was collected from 60 humanitarian organisations. Potential respondents were five officers from each humanitarian organisation involved in delivering humanitarian assistance. Respondents from the different organisations were selected using purposive sampling. The SPSS software, SMART PLS and CB-SEM software were used to obtain results on the influence of relational capital on inter-cluster coordination and service delivery in humanitarian organisations; and the mediating and moderating role of inter-cluster coordination on the relationship between relational capital and service delivery.FindingsFindings indicated that relational capital influences inter-cluster coordination and service delivery in humanitarian relief chains; inter-cluster coordination partially mediates the relationship between relational capital and service delivery in humanitarian relief chains; and no interactive effect was found when the moderation effect of inter-cluster coordination on the relationship between relational capital and service delivery in humanitarian organisations was examined.Research limitations/implicationsThe study was mainly focused on humanitarian organisations excluding beneficiaries and the logistics suppliers. The research has implications to decision-makers in government and humanitarian organisations concerned with providing relief aid to beneficiaries.Originality/valueThe influence of relational capital on inter-cluster coordination and service delivery in humanitarian relief chains; the mediating role and moderating role of inter-cluster coordination on the relationship between relational capital and service in humanitarian relief chains are aspects that have not been given significant attention empirically.

Network Partition and Voltage Coordination Control for Distribution Networks With High Penetration of Distributed PV Units

In order to solve the voltage violation problem caused by high penetration of photovoltaic (PV) units in distribution power networks, this paper proposes a double-layer voltage control strategy based on the distribution network partition. By optimizing the active and reactive power outputs of PV units, the minimization objective of PV active power curtailment and network active power loss can be achieved. In the basis of community detection algorithm, a novel cluster performance index based on the electrical distance and regional voltage regulation capability is presented to partition a distribution network into several clusters. The proposed double-layer voltage control strategy combines the cluster autonomous optimization and distributed intercluster coordination optimization in different time scales. The cluster autonomous optimization can eliminate intracluster voltage violation rapidly by alternately updating the intracluster optimal solution and the virtual slack bus voltage. The distributed intercluster coordination optimization with a long-time scale is based on the alternating direction method of multipliers and realizes global optimal control through finite boundary data exchange among adjacent clusters. The effectiveness and feasibility of the proposed method have been demonstrated via simulation tests on a real 10.5 kV feeder in China and the IEEE 123-bus system.

User-Centric Overlapped Clustering Based on Anchor-Based Precoding in Cellular Networks

Coordinated multipoint (CoMP) is a promising technique for improving the performance of cell edge users, where a number of base stations (BSs) form a cluster to jointly process signals to the users within the cluster. Based on nonoverlapped clustering, dynamic clustering and intercluster co-ordination were proposed to mitigate interference to users at cluster edges. However, to further enhance the performance of cluster-edge users, user-centric overlapped clustering is more effective in providing multiuser MIMO and intercluster CoMP from multiple BSs belonging to different clusters. In this letter, on the basis of an anchor-based precoding scheme, an optimal user-centric clustering scheme is introduced together with a suboptimal clustering algorithm. The throughput performance is evaluated and compared with conventional nonoverlapped clustering in multicluster environments.

GSM: gateway selection mechanism for strengthening inter-cluster coordination in cognitive radio ad hoc networks

Abstract In the open access spectrum paradigm, the dynamics of the available spectrum heterogeneity due to the geographical location of various cognitive radio/secondary users (SUs) and primary users (PUs) prevent the assignment of a single common control channel to every SU. Thus, depending on channel availability, SUs are forced to form clusters to solve the problem of control channel assignment. However, the sudden appearance of a PU may lead to loss of intra-cluster or inter-cluster connectivity among SUs. This problem can be resolved by improving the cluster formation process and selecting suitable gateway nodes for inter-cluster coordination. In this paper, our goal is to improve inter-cluster connectivity by selecting more appropriate gateway nodes for inter-cluster coordination. We therefore propose an inter-cluster gateway node selection mechanism that strengthens inter-cluster coordination. Our scheme shows significant improvement in terms of inter-cluster connectivity compared with related work.

EEICCP—Energy Efficient Protocol for Wireless Sensor Networks

In this paper, an energy efficient inter cluster coordination protocol developed for the wireless sensor networks has been proposed. By controlling the topology, longevity and the scalability of the network can be increased. Clustering sensor node is an effective topology for the energy constrained networks. So cluster based algorithm has been developed in which different levels of clusters are considered on the basis of received signal strength to recognize the distance of the clusters from the BS (base station) and to determine the number of cluster coordinators to make routes for the CHs to transmit the data. Based on the investigation of existing protocols in which cluster heads send data directly to the base station, it is found that direct transmission by the CHs is not an optimal solution and dissipates a lot of energy, so in this paper a novel EEICCP (Energy efficient inter cluster coordination) protocol has been proposed which evenly distributes the energy load among the sensor nodes and use the multi hop approach for the CHs. Analytical model of new protocol is projected and the algorithm is implemented in MATLAB. Moreover, EEICCP has shown remarkable improvement over already existing LEACH and HCR protocols in terms of reliability and stability. Our work has also been validated through the simulation results.

A collaborative node management scheme for energy-efficient monitoring in wireless multimedia sensor networks

Clustering in sensor networks provides energy conservation, network scalability, topology stability, reducing overhead and also allows data aggregation and cooperation in data sensing and processing. Wireless Multimedia Sensor Networks are characterized for directional sensing, the Field of View (FoV), in contrast to scalar sensors in which the sensing area usually is more uniform. In this paper, we first group multimedia sensor nodes in clusters with a novel cluster formation approach that associates nodes based on their common sensing area. The proposed cluster formation algorithm, called Multi-Cluster Membership (MCM), establishes clusters with nodes that their FoVs overlap at least in a minimum threshold area. The name of Multi-Cluster Membership comes from the fact that a node may belong to multiple clusters, if its FoV intersects more than one cluster-head and satisfies the threshold area. Comparing with Single-Cluster Membership (SCM) schemes, in which each node belongs to exactly one cluster, because of the capability of coordination between intersected clusters, MCM is more efficient in terms of energy conservation in sensing and processing subsystems at the cost of adding complexity in the node/cluster coordination. The main imposed difficulty by MCM, is the coordination of nodes and clusters for collaborative monitoring; SCMs usually assign tasks in a round-robin manner. Then, as second contribution, we define a node selection and scheduling algorithm for monitoring the environment that introduces intra and inter-cluster coordination and collaboration, showing how the network lifetime is prolonged with high lifetime prolongation factors particularly in dense deployments.

Protecting the right to health of internally displaced mothers and children: the imperative of inter-cluster coordination for translating best practices into effective participatory action

Substantive progress has been achieved in advancing emergency response interventions during disasters including assistance of internally displaced persons (IDPs). Explicit operational technical guidelines and management strategies have been successfully applied through the "cluster approach". In 2008-09 armed conflict in several districts of the Khyber Pakhtunkhwa (KP) province and the Federally Administered Tribal Areas (FATA) of Pakistan resulted in over 2.7 million IDPs. This report describes the response by the Pakistan government, assisted by the hosting populations and humanitarian partners, to deal with the crisis using the cluster approach to ensure the health protection of the IDPs, particularly mothers and children.

Networked MIMO with clustered linear precoding

A clustered base transceiver station (BTS) coordination strategy is proposed for a large cellular MIMO network, which includes full intra-cluster coordination-to enhance the sum rate-and limited inter-cluster coordination-to reduce interference for the cluster edge users. Multi-cell block diagonalization is used to coordinate the transmissions across multiple BTSs in the same cluster. To satisfy per-BTS power constraints, three combined precoder and power allocation algorithms are proposed with different performance and complexity tradeoffs. For inter-cluster coordination, the coordination area is chosen to balance fairness for edge users and the achievable sum rate. It is shown that a small cluster size (about 7 cells) is sufficient to obtain most of the sum rate benefits from clustered coordination while greatly relieving channel feedback requirement. Simulations show that the proposed coordination strategy efficiently reduces interference and provides a considerable sum rate gain for cellular MIMO networks.