- EI核心期刊
A new fault detection mechanism based on historical data and neighbor-coordination was presented. It gives the combination of detection methods was given based on historical data with the detection ways from neighbor-coordination. Simulation shows that the fault detection mechanism based on historical data and neighbor-coordination can be not only applied to the scene where the nodes are randomly distributed, but also for scenarios in which the failed nodes are intensive. The detection accuracy can reach 96.7% or more although the average degree of the nodes reduces or the failure rate of the nodes increases. In addition, different nodes only communicate few messages with each other in this detection mechanism. And thus, the energy of the node and the bandwidth of the channel can be saved.
In order to solve the problem of reasonable resource scheduling in virtual computing environment (iVCE), the optimization for resource clustering technology was carried out. A resource matching algorithm (fuzzy clustering scheduling) based on fuzzy clustering was proposed. Scheduling strategy for different resources with different tasks and attributes was put forward in the proposed model. The algorithm narrows choices of resources and directly reduces the space complexity of the original resource.
For security flaws in 4G authentication and key agreement protocol, an efficient and secured authentication and key agreement (ES-AKA) protocol was proposed. This protocol resists redirection attack and replay attack, solves security risks that key K is possible leaked. Analyzing of the security and efficiency of ES-AKA shows that ES-AKA could reduce not only the storage of service network but also the computation of home network, and has less bit exchange traffic in higher security environment.
To achieve rational and efficient usage of radio spectrum, a priority-based packet scheduling mechanism on cognitive radio sensor networks for smart grid was presented. It provides higher priority secondary user packets with relatively high quality of service (QoS) without interfering the transmission of important business for network control. Based on differentiated scheduling method, communication traffic in smart grid was classified into several priority classes according to characteristics and QoS requirements of heterogeneous business. And then, a radio spectrum allocation strategy was formulated which considered the effect of channel quality and the cost of switch. Simulation was implemented to evaluate the mechanism by using Matlab. The simulation results show that the transmission quality of the higher-priority secondary users is improved by adopting the proposed priority-based packet scheduling mechanism and the overall system utilization is increased as well.
The cluster-based periodic data collection for wireless sensor networks, the sensor nodes deployed in monitoring region periodic transmit data to sink nodes were considered. The spatial correlation in collected data increases the redundancy of data and network energy consumption. An algorithm was proposed to prolong the lifetime of wireless sensor network and ensure the fidelity of collected data. A frequent itemset mining-based spatial subclustering algorithm was proposed. Analysis and experiment show that the improved algorithm can achieve more energy savings, extend the wireless sensor networks lifetime and guarantee the fidelity of collected data.
How to limit impact of the availability of power communication services caused by random failures was presented. The business model of the cumulative probability of failure channel beyond prescribed time is defined as failure risk of service channel. A mathematical model for fluctuations of service channel availability was built and a probabilistic model of service channel failure risk was derived. This model proposed a planning decision parameter of channel routing algorithm based on random selection algorithm of failure risk degree of electric power communication service. Simulations verify the effectiveness of the algorithm.
In order to raise the rate of service searching success and reduce the rate of service executing interruption, the reliability-predicted service discovery & selection protocol (RPD&S) was proposed. A new mobile model of nodes could predict the mobility and available time of nodes, calculate the reliability of service provider nodes and the path, and then select the service provider node and the path with high reliability. Meantime, a double path was built between service request nodes and provider nodes. Simulation shows RPD&S can reduce failure rate of searching service and interrupt rate of execution. It also proves that RPD&S can solve the problems in service discovery and selection and improves the user experience.
The node access has been paid more attentions in network decision making. An accurate evaluation of wireless channel was investigated. A method based on the process of sensing that is a trade-off between the accuracy of channel sensing and channel idle time, was employed to evaluate the wireless channel. Furthermore, the impact of the sensing parameters including sensing time, sampling frequency on the channel quality was analyzed. An optimal sensing time and sampling frequency was derived to maximize the value of channel quality. Simulations verify the analysis validity.
A new satellite handover scheduling algorithm based on the maximum residual service time was proposed. The algorithm exploits both global positioning system (GPS) infrastructure and satellite diversity, providing a simple and real-time handover management in low earth orbit (LEO) satellite networks to minimize the expected number of satellite handovers. It reduces the users' call drop probability ultimately. Simulations were carried out on the typical Iridium satellite network and the simulation results corroborate the advantages gained by the proposed algorithm.
Different from traditional routing protocols in smart grid, the sudden congestion is no longer as main risk for data collection. The source of risk is currently key node congestion in network. A routing mechanism was proposed to realize reliable data acquisition of electric data transmission for load balance of network congestion. Firstly, an abstract mathematical model of communication network was built. Secondly, the routing protocol for wireless mesh networks (WMNs) was used. The node queue length was regarded as the decision parameters to establish a routing metric model (Data Balance Measurement Model, DBMM) corresponding to the routing algorithm based on the balanced tree (Routing Algorithm based on DBMM, RA-DBMM). Simulation was carried out in MATLAB environment, the performance was compared between the RA-DBMM algorithm and the classical Bellman-Ford algorithm. Experiments show that RA-DBMM algorithm can effectively improve the problem of data congestion, and improve the reliability and throughput of network.
Efficient network traffic prediction method can improve the efficiency of network management. On account of problems of network traffic if as burst, time-varying, nonlinear problems happen that caused by various coefficients, a distributed network traffic prediction method was proposed obeyed by intelligent optimization. The fruit fly optimization algorithm was adopted in this method to optimize the smoothing coefficients of traditional triple exponential smoothing forecasting model. By predicting network traffic that is collected within time windows, this method effectively improves the efficiency of network traffic prediction. Simulation indicates that, compared with traditional triple exponential smoothing forecasting model, the proposed prediction model can solve the problem of prediction error caused by smoothing coefficient. The optimal smoothing coefficient can be selected adaptively, thus improves the prediction accuracy.
A Hilbert spectrum-based approach to specific emitter identification(SEI)was proposed in single-hop and relaying scenarios. The correlation coefficient measuring the similarity between Hilbert spectrums was employed as the identification feature. An identification problem was also in-depth explored for a relaying scenario, in which the fingerprint of different emitters can be impaired by the relay's fingerprints under non-ideal conditions, such as non-Gaussian noise and flat-fading channels. Extensive simulation demonstrates that the proposed approach can achieve a good identification performance in both single-hop and relaying scenarios, and shows robust against non-ideal channel conditions as well.
Stream transmission control protocol (SCTP) in the electric power communication network and transmission line can be failed simultaneously onto both fast and reliable Wide-area backup protection action. However, when the primary path failure results in performance degradation and disconnection when error occurs, the problem mentioned above leading Wide-Area backup would not be timely acted. To solve this problem, the main path was analyzed based on delay automatic switching paths comprehensive evaluation method which was based on the primary path automatically switching method. The main path automatically switched Wide-area backup protection of information and communication transmission were also introduced. The NS2 simulation environment is verified. Experiments show that the path-based comprehensive evaluation method of main path automatically switch the primary path reduces time consumption and improves wide-area backup protection communication transmission reliability.
As a kind of information leaking carrier, printed documents are recently becoming a large security risk. Tracing document with watermarks is an effective resolution to the problem. It is found out that the heights of neighboring characters from nature text are usually not the same, and most height relationships between character pairs keep reserved after print-scan. According to it, this paper proposes a new robust watermark method by modifying character's height. Besides, only those character pairs with similar complexity will be chosen to achieve better transparency. Experiments show that the watermark can be extracted from the texts distorted due to print-scan, print-copy, or print-photograph.
A double clustering model to make web log data sets clustering was proposed based on the self-organizing map (SOM) neural networks and the fuzzy c-means (FCM) method. The first tier uses unsupervised clustering method—SOM neural network, so the number of classes it generates significantly reduces compared with the original data set, it also reduces the FCM method's rely on class initial centers. Using the FCM clustering algorithm to cluster the center points of classes generated by the first layer, the time complexity of clustering is greatly reduced. Meanwhile, the parallel coordinates visualization technology to demonstrate the log dataset was used, it is suitable to analyze the log data.
To improve the accuracy of speech emotion recognition, a multi-class classifier with binary-tree structure is adopted, which includes building the multi-kernel support vector machine (SVM) classifier model solved by semi-definite programming method, and using the root mean square error and maximum error to evaluate the performance of the classifier. Through the test on the parameter set obtained by feature selection algorithm, the results of experiments show that the total recognition accuracy of the proposed multiple-kernel SVM classifier model using semi-definite programming is 88.614%, which is 12.376% higher than that of single-kernel SVM model. Moreover the multiple-kernel SVM model can reduce the total error accumulation and confusion between emotion states.
In order to optimize the high energy consumption and to keep certain quality of service in the cloud computing data center, an optimization method for performance and energy aware was proposed. Firstly, local regression was used to determine whether the host is overloaded and using mean value determined whether the host is underloaded. And then, the virtual machine of the overloaded host was shifted into queue according to the minimum migration times and the maximum or minimum CPU utilization strategy. Finally, the performance and energy aware algorithm was designed to deploy the virtual machine in the queue and underloaded host. Simulations show that the proposed algorithm not only improves system performance but also reduces system energy consumption.
The development of cloud storage service is one of the key elements to cloud data technology. New data storage architecture for cloud storage service based file systems was proposed. And the design and implementation of cloud storage-backed file system based on the architecture (CSFS) was described. The development and deployment costs are reduced by utilizing free email service. The efficiency and scalability are increased by separated management of metadata, data block, distributed storage and cloud data prefetching. Experiments show that the optimization method improves the read and write performance of the system effectively.
Ancillary service is a new service field for civil aviation to improve the travel experience for customers and obtain value-added income. Compared with traditional airlines services, the ancillary services could satisfy the personalized requirements. In order to effectively and smoothly provide personalized value-added services, it is necessary to establish a passenger interest model. Based on characteristics of ancillary services, a new representation method for passenger interest model of airlines ancillary services was proposed. The collection method for interest data was analyzed and the evolving algorithm for the interest model was proposed as well. At last, the interest model and its effectiveness verification were implemented by means of application and experiment.
Three types of attacks' scenarios were described when there exists or not sequence number (SQN) in UMTS AKA. Analysis shows that the use of SQN cannot resist replay attacks effectively. Based on that, three new protocols using one-time random number were further analyzed and simulated to resist replay attacks. It is shown that AP-AKA and AKA based on public key cryptography can effectively against replay attacks. However, AP-AKA will add storage and computing resources of entities and AKA based on public key cryptography promotes the complexity of algorithm, but S-AKA only keeps against replay attacks partially.
Multipath transport system based on application-level relay (MPTS-AR) is a multipath transport system model based on application-level relay. It uses user datagram protocol relay server to establish multiple paths for point-to-point session and supports multiple services. A method was proposed to create MPTS-AR network simulation basing on INET Framework of OMNeT++ platform, including how to create network topology, to implement logical entities (user agent, relay controller, relay server), and to define and process messages. The key and difficult points about application program interface compatibility and supporting multi-service were also discussed. H.264 service based simulation was carried out. It is shown the correctness and effectiveness of MPTS-AR network simulation.
According to the analysis of application requirements, authentication, authorization, accounting and audit (4A) enabler in platform as a service (PaaS) platform was designed and implemented. To verify the usability of the 4A enabler and its application prospects in PaaS, a personalized recommendation application was brought forward using the open application programming interfaces of the 4A enabler. 4A enabler in PaaS mentioned here not only enriches the capabilities of the PaaS Platform, but also simplifies the application development.
Convolutional neural network (CNN) currently becomes research focus for image recognition. The visual features extracted from the pre-trained CNN demonstrate powerful ability for various recognition tasks. The performance of traditional visual features and CNN visual features for content-based image retrieval was mainly compared. Experiments on the two public available datasets of Pascal Sentence and Pascal VOC 2007 show that, a sufficient performance of CNN visual features used in image retrieval when compared with traditional visual features.
According to the characteristics that the sensor nodes in underwater sensor network (UWSN) adopt acoustic communication, characterized by high error rate high delay, low bandwidth, multipath and Doppler shift, etc., the current communication protocols designed for radio channels are unsuitable for underwater. So, a new dynamic and distribute code division multiple access (CDMA)-based media access control (MAC) protocol for UWSN was proposed. The protocol not only can save the limited energy of mobile nodes,but also increase the CDMA code reusability. The protocol can be adapted to the dynamic topology of UWSN. At the same time, the design of power control can minimize the near-far effect inherit in CDMA. Simulation indicates that, compared with the static code assignment protocol and ALOHA, the performance of the protocol mentioned above is satisfied on delivery ratio and end-to-end delay.
In multi-task automatic networks,a node-selfishness model was presented to manage the degree of internal selfishness which formulates the effect of its own resource on the node-selfishness, and to manage the degree of external selfishness that reflects the effect of the external factor (task characterization and incentive/punishment mechanism) on the node-selfishness. Given an incentive/punishment mechanism, the minimum resource-consumption compensation paid by an automatic node to the nodes around for forwarding multiple tasks is determined in terms of their information on the node-selfishness. Furthermore, this automatic node can predict the node-selfishness of the nodes around this node.
The smart grid does provide people with enormous benefits, however, but it possibly leads to serious security problems. The cyber attack on real-time pricing (RTP) is of great significance, but people pay less attention to. Focused on delay attack, a dynamic model for behavior of both consumers and suppliers in electrical power markets was established. Based on the model, a defensive pricing strategy using robust control theory and Lyapunov function was put forward. At last, the effectiveness of the proposed strategy was validated through a numerical simulation example.
A double limited and heterogeneous social network was proposed to analyze the structure of social network in China, namely the limited size of the network and in-degree and out-degree of the nodes, and the heterogeneous attributes of the nodes. Compared with the small-world and scale-free network, the double limited and heterogeneous social network can better simulates the real social network. It not only has the overall structure characteristics of the small-world and scale-free network, but also reflects the influence and control of the different types of nodes in the social network at the micro level.