Current Issue : July - September Volume : 2020 Issue Number : 3 Articles : 5 Articles
In todayâ??s Internet, a web user becomes members of multiple social networks due to different types of services provided by each of\nthese networks. This creates an opportunity to make trust decisions that go beyond individual social networks, since these\nnetworks provide single perspective of trust. To make trust inference over multiple social networks, these networks need to be\nconsolidated. It is nontrivial as these networks are of heterogeneous nature due to different naming conventions used in these\nnetworks. Furthermore, trust metrics extracted from these networks are also varied in nature due to different trust evaluation\nalgorithms used in each of these networks........................
In this paper, we investigate the performance of the non-orthogonal multiple access (NOMA) system with incremental relaying,\nwhere the relay is employed with amplify-and-forward (AF) or decode-and-forward (DF) protocols. To characterize the outage\nbehaviors of the incremental cooperative NOMA (ICN) system, new closed-form expressions of both exact and asymptotic\noutage probability for two users are derived. In addition, the performance of the conventional cooperative NOMA (CCN)\nsystem is analyzed as a benchmark for the the purpose of comparison. We confirm that the outage performance of the distant\nuser is enhanced when ICN system is employed. Numerical results are presented to demonstrate that (1) the near user of the\nICN system achieves better outage behavior than that of the CCN system in the low signal-to-noise ratio (SNR) region; (2) the\noutage performance of distant user for the DF-based ICN system is superior to that of the AF-based ICN system when the\nsystem works in cooperative NOMA transmission mode; and (3) in the low SNR, the throughput of the ICN system is higher\nthan that of the CCN system....
In many fields, multiple RFID tags are often combined into a group to identify an object. An RFID grouping-proof protocol is\nutilized to prove the simultaneous existence of a group of tags. However, many current grouping-proof protocols cannot simultaneously\nprovide privacy preserving, forward security, and the authentication between reader/verifier and tags, which are\nvulnerable to trace attack, privacy leakage, and desynchronization attack. To improve the secure performance of the current\ngrouping-proof protocols, we propose two provable lightweight grouping-proof protocols that provide forward security, identity\nauthentication, and privacy preserving. Our protocols involve a trusted reader and an untrusted reader, respectively. In order to\navoid verifying some invalid evidences, our protocols complete the authentication of the verifier to the trusted reader and the\nverified tags before the verifier verifies the grouping-proof evidence. Each tag uses parallel mode to complete its signature to\nimprove the efficiency of the protocols. Moreover, the activate-sleep mechanism and the filtering operation are proposed to\neffectively reduce the collision probability and computing load of tags. Our protocols complete the authentication to tags twice by\na verifier and a trusted reader, respectively. They can resist various attacks such as eavesdropping, replay, trace, and\ndesynchronization. The protocols are proven to be secure, flexible, and efficient. They only utilize some lightweight operations.\nTherefore, they are very suitable to the low-cost RFID systems....
In this paper, we investigate the transmit power allocation problem to minimize the average packet error rate at the access point in\nthe cluster flight spacecraft network, which adopts the CSMA/CA channel access mechanism. First, the node mobility, nodal\ndistance distribution, and probabilistic adjacency matrix were formulated for cluster flight spacecraft network based on twinsatellite\nmode. Then, the optimization-theoretic model described the optimized transmit power allocation strategy and its\nimplementation algorithm was proposed. And the problem of minimizing the packet error rate of the cluster flight spacecraft\nnetwork system can be converted into maximizing the expectation of the binary probabilistic adjacency matrix, i.e., maximizing\nthe sum of the nondiagonal elements in the probabilistic adjacency matrix. Due to discreteness of nodal distance distribution,\nMonte Carlo method was applied to solve the transmit power allocation problem. Yet importantly, the influence of node transmit\npower on the QoS performance of cluster flight spacecraft network was simulated and analyzed under the assumption of finite\noverall network transmit power and low traffic load. Finally, the results show that the pocket error rate increases with the provided\ntraffic load, but the pocket error rate hardly changes with the same traffic load in different sequential time slots of any orbital\nhyperperiod or in the same time slot of different orbital hyperperiods, and by maximizing the sum of the nondiagonal elements in\nthe probabilistic adjacency matrix, the pocket error rate minimum is achieved for a given total network transmit power at any time\nslot for cluster flight spacecraft network....
Along with the development of the Internet of Things (IoT), waste management has appeared as a serious issue. Waste\nmanagement is a daily task in urban areas, which requires a large amount of labour resources and affects natural,\nbudgetary, efficiency, and social aspects. Many approaches have been proposed to optimize waste management, such as\nusing the nearest neighbour search, colony optimization, genetic algorithm, and particle swarm optimization methods.\nHowever, the results are still too vague and cannot be applied in real systems, such as in universities or cities. Recently,\nthere has been a trend of combining optimal waste management strategies with low-cost IoTarchitectures. In this paper, we\npropose a novel method that vigorously and efficiently achieves waste management by predicting the probability of the\nwaste level in trash bins. By using machine learning and graph theory, the system can optimize the collection of waste with\nthe shortest path. This article presents an investigation case implemented at the real campus of Ton Duc Thang University\n(Vietnam) to evaluate the performance and practicability of the systemâ??s implementation. We examine data transfer on the\nLoRa module and demonstrate the advantages of the proposed system, which is implemented through a simple circuit\ndesigned with low cost, ease of use, and replace ability. Our system saves time by finding the best route in the management\nof waste collection....
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