Magnetic induction (MI) communication is a promising technology for next-generation low-power underwater wireless sensor networks (UWSNs). clustering algorithm design becomes an important and challenging issue in toda...
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Magnetic induction (MI) communication is a promising technology for next-generation low-power underwater wireless sensor networks (UWSNs). clustering algorithm design becomes an important and challenging issue in today's MI-based UWSNs. In contrast to the conventional approaches which suffer from continuous movement of ocean current and traffic loads in different areas of the network, we consider a clustering algorithm based on the Voronoi diagram and node density distribution to improve the energy efficiency and to prolong the network lifetime. In particular, we propose a jellyfish breathing process for cluster head selection and an automatic adjustment algorithm for sensor nodes. The simulation results show that the proposed clustering algorithm achieves a high network capacity rate and a good equalization for the remaining energy.
For most small and medium-sized enterprise (SME), the establishment of special customer management system requires specialized hardware and professional technicians, which will greatly increase the management cost of ...
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For most small and medium-sized enterprise (SME), the establishment of special customer management system requires specialized hardware and professional technicians, which will greatly increase the management cost of enterprises. Customer relationship management (CRM) based on cloud computing can not only reduce the management cost of SME, but also improve the business agility of SME, and help SME create new business models and market opportunities. In this study, a CRM system based on customer service is designed by using the customer classification method based on the improved K-means clustering algorithm. The system adopts the system architecture model based on network to realize the information interaction and resource sharing among different roles. The management of customer service is the core content of system design and development, and it realizes the development of CRM system for SME. The whole system effectively solves the problems such as low efficiency and limited service provision of customer management, as well as the low integrity of customer work, so as to achieve the purpose of improving the management capacity of SME.
In this paper, we propose a new distance metric for the K-means clustering algorithm. Applying this metric in clustering a dataset, forms unequal clusters. This metric leads to a larger size for a cluster with a centr...
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In this paper, we propose a new distance metric for the K-means clustering algorithm. Applying this metric in clustering a dataset, forms unequal clusters. This metric leads to a larger size for a cluster with a centroid away from the origin, rather than a cluster closer to the origin. The proposed metric is based on the Canberra distances and it is useful for cases that require unequal size clusters. This metric can be used in connected autonomous vehicle wireless networks to classify mobile users such as pedestrians, cyclists, and vehicles. We use a combination of mathematical and exhaustive search to establish its validity as a true distance metric. We compare the K-Means algorithm using the proposed distance metric with five other distance metrics for comparison. These metrics include the Euclidean, Manhattan, Canberra, Chi-squared, and Clark distances. Simulation results depict the effectiveness of our proposed metric compared with the other distance metrics in both one-dimensional and two-dimensional randomly generated datasets. In this paper, we use three internal evaluation measures namely the Compactness, Sum of Squared Errors (SSE), and Silhouette measures. These measures are used to study the proper number of clusters for each of the K-Means algorithms and also select the best run among multiple centroid initializations. The elbow method and the local maximum approach are used alongside the evaluation measures to select the optimal number of clusters.
Unlike many traditional feature extraction methods of vibration signal such as ensemble empirical mode decomposition (EEMD), deep belief network (DBN) in deep learning can extract the useful information automatically ...
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Unlike many traditional feature extraction methods of vibration signal such as ensemble empirical mode decomposition (EEMD), deep belief network (DBN) in deep learning can extract the useful information automatically and reduce the reliance on experts, with signal processing technology, and troubleshooting experience. In conventional fault diagnosis, data labels are required for classifiers such as support vector machine, random forest, and artificial neural networks. These are usually based on expert knowledge, for training and testing. But the process is usually tedious. The clustering model, on the other hand, can finish the roller bearings fault diagnosis without data labels, which is more efficient. There are some common clustering models which include fuzzy C-means (FCM), Gustafson-Kessel (GK), Gath-Geva (GG) models, and affinity propagation (AP). Unlike FCM, GK, and GG, which require knowledge or experience to pre-set the number of cluster center points, AP clustering algorithm can obtain the cluster center point according to the responsibility and availability calculations for all data points automatically. To the best of the authors' knowledge, AP is rarely used for fault diagnosis. In this paper, a method which combines DBN, with several hidden layers, and AP for roller bearings fault diagnosis is proposed. For data visualization, the principal component analysis (PCA) is deployed to reduce the dimension of the extracted feature. The first two principal components are employed as the input of the FCM, GK, GG, and AP models for roller bearings faults diagnosis. Compared with other combination models such as EEMD-PCA-FCM/GK/GG and DBN-PCA-FCM/GK/GG, the proposed method, from the experimental results, is superior to the aforementioned combination models.
Smartphones have been advocated as the preferred devices for travel behavior studies over conventional surveys. But the primary challenges are candidate stops extraction from GPS data and trip ends distinction from no...
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Smartphones have been advocated as the preferred devices for travel behavior studies over conventional surveys. But the primary challenges are candidate stops extraction from GPS data and trip ends distinction from noise. This paper develops a Resident Travel Survey System (RTSS) for GPS data collection and travel diary verification, and then uses a two-step method to identify trip ends. In the first step, a density-based spatio-temporal clustering algorithm is proposed to extract candidate stops from trajectories. In the second step, a random forest model is applied to distinguish trip ends from mode transfer points. Results show that the clustering algorithm achieves a precision of 96.2%, a recall of 99.6%, mean absolute error of time within 3?min, and average offset distance within 30 meters. The comprehensive accuracy of trip ends identification is 99.2%. The two-step method performs well in trip ends identification and promotes the efficiency of travel survey systems.
作者:
Yan, XiangXu, JiaNorthwest Univ
Sch Informat Sci & Technol 1 Xuefu AveGuodu Educ Technol Ind Pk Xian 710000 Peoples R China Northwestern Polytech Univ
Sch Elect & Informat 1 Xuefu AveGuodu Educ Technol Ind Pk Xian 710000 Peoples R China
Currently, unmanned aerial vehicle (UAV) group Internet of Things (IoT) has poor stability, poor endurance, and low security. In this regard, we report a polygon area UAV group IoT clustering algorithm for large-scale...
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Currently, unmanned aerial vehicle (UAV) group Internet of Things (IoT) has poor stability, poor endurance, and low security. In this regard, we report a polygon area UAV group IoT clustering algorithm for large-scale, high-speed mobile IoT environment. First, the UAV group IoT was divided into a polygon area and a few cluster heads were used to cover the polygon area uniformly. Then, the clustering index in the maximum speed similarity clustering algorithm was induced into the weighted clustering algorithm. Simultaneously, the link retention rate, relative node degree, and node residual energy ratio were improved to select the IoT node with the maximum weight as the cluster head. Finally, the IoT security was improved by reputation calculation. The results show that the clustering algorithm in this paper can reduce the number of clusters and lower the handover rate between clusters, improve the stability of clustering, prolong the survival time of the minimum node, improve the overall endurance of the IoT, and have high security.
Solving a clustering algorithm can usually be simplified into an optimization problem. Using relevant knowledge in graph theory, many optimization problems can be transformed into solving minimum spanning tree problem...
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Solving a clustering algorithm can usually be simplified into an optimization problem. Using relevant knowledge in graph theory, many optimization problems can be transformed into solving minimum spanning tree problems. Minimal spanning trees are also widely used in areas closely related to cognitive computing such as for face recognition by face cognition and gene data analysis by gene cognition. However, the minimum spanning tree has the shortcoming of the distance between neighbours because of which the minimum spanning tree algorithm cannot cluster unbalanced data. Thus, the face recognition rate is low, and facial expression cognition is difficult. In this paper, a minimum spanning tree algorithm based on fuzzy distance is proposed for the shortcomings of the minimum spanning tree (FCP). First, a relative neighbourhood distance measure is proposed by introducing neighbourhood rough set theory;the neighbourhood matrix is obtained based on the distance. Second, the minimum spanning tree is solved by the prim algorithm and the neighbourhood matrix. Finally, the minimum spanning tree is partitioned to realize clustering of the minimum spanning tree. In this paper, the UCI dataset and Olivetti face database are selected to verify the performance of the algorithm, and the algorithm is evaluated by three evaluation criteria. The experimental results show that the proposed algorithm can not only cluster data of any shape but also deal with unbalanced data containing noise points. Especially in face cognitive computing, the values of ACC, AMI, and ARI can reach 0.852, 0.843, and 0.782, respectively. In this study, the algorithm can obtain very good clustering results for data with good geometric structure, and the overall performance is better than other algorithms. In face recognition detection, the improved cognitive computing of faces makes it possible to accurately recognize different expressions from the same person.
In the Industrial Internet of Things (IIoT), wireless sensor network (WSN) technology makes devices that communicate with each other. The information integrated from multiple data sources will be transformed into prod...
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In the Industrial Internet of Things (IIoT), wireless sensor network (WSN) technology makes devices that communicate with each other. The information integrated from multiple data sources will be transformed into productivity. However, the clusters close to the base station take a considerable load over multi-hop transmission, and in this case, the lifetime of the industrial WSN is restricted. To solve this problem, a grid-based clustering algorithm via load analysis for IIoT is presented in this paper. First, the network load is quantitatively analyzed and then a load model is constructed. Furthermore, a set of expressions is deduced to indicate the network load distribution. It is concluded that the number of delivered packets in each level is related to the grid length at that level. The optimal grid length is obtained by solving polynomials to achieve the uniform energy consumption of nodes at each level. Finally, the network is partitioned into unequal grids according to the optimal cluster size and all the nodes of a grid are formed into a cluster. Results of the experiments show that compared with ACT, ER-HEED, and RUHEED, our algorithm balances energy depletion effectively and extends the whole network lifetime.
To protect the privacy of users, tables generally must be anonymized before publication. All existing anonymous methods have deficiencies. They do not consider the differences in attributes, or the optimization of inf...
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To protect the privacy of users, tables generally must be anonymized before publication. All existing anonymous methods have deficiencies. They do not consider the differences in attributes, or the optimization of information loss and time efficiency. his paper proposes a new method called KACM to realize k-anonymity. This method is mainly used for hybrid tables. The calculation of the distance between records considers the connection between quasi-identifier attributes and sensitive attributes, their effect on the sensitive privacy, and the information loss during the anonymity process. In the clustering process, the records with the minimum distance are always selected to add, and the clustering is individually controlled according to k to realize the equalization division of the equivalence class and reduce the total amount of distance calculation. Finally, the validity and practicability of the method are proved using theory and experiment. (C) 2019 Elsevier Inc. All rights reserved.
Recently, extensive research efforts have been devoted to the design of efficient clustering algorithms to divide all the nodes in a mobile ad hoc network into multiple clusters to form a clustered architecture. A clu...
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Recently, extensive research efforts have been devoted to the design of efficient clustering algorithms to divide all the nodes in a mobile ad hoc network into multiple clusters to form a clustered architecture. A clustered architecture is more stable if it can hold for a longer period of time. In a clustered architecture, due to node mobility, a node may depart from its original cluster and enter another cluster dynamically. Such a change may cause the clustered architecture to be reconfigured, leading to the instability of the network. Frequent information exchanges among the participating nodes and re-computation of clusters involve high communication and computation overheads. Therefore, it is obvious that a more stable clustered architecture will directly lead to the performance improvement of the whole network. In this paper, we propose an efficient clustering algorithm that can establish a more stable clustered architecture by keeping a node with many weak links from being selected as a clusterhead. Computer simulations show that the clustered architectures generated by our clustering algorithm are more stable than those generated by other clustering algorithms.
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