Vehicular edge computing (VEC) has been recognized as a promising technique to process delay-sensitive vehicular applications. Nevertheless, in order to accommodate the rapid growth in the number of connected vehicles, it’s inevitable that there will be an increasing deployment of conventional infrastructure with limited communication ranges. This could potentially lead to escalating costs and impede the full realization of the VEC system. In this paper, a roadside intelligent reflecting surface (IRS) assisted VEC network is introduced, where the IRS is deployed outside the coverage of roadside units (RSUs) to extend the service range. Furthermore, the maximum total number of successful offloading tasks problem within the scheduling time problem is formulated, encompassing the optimization of offloading decisions, computation resource allocation and phase shift of IRS. To tackle the formulated challenging problem, we first decouple the original problem into two subproblems. Then, a heuristic algorithm is proposed, where a many-to-one matching algorithm is proposed to joint optimize offloading decision and the computation resource, and an iterative algorithm is utilized to optimize the phase shift coefficients of IRS. The simulation results validate the effectiveness of the proposed algorithm in comparison to other schemes, and the IRS can effectively maintain network performance even when there are intervals in RSU coverage areas.
During emergency scenarios, network access may be disrupted due to damaged Base Stations (BSs), and deploying Unmanned Aerial Vehicles (UAVs) as communication relays is common in rescue scenarios due to their convenience in ensuring network access. In such situations, the dissemination of rescue-related information messages is crucial, and broadcast messages are often prioritized. Thus, ensuring high broadcast throughput while guaranteeing accessibility for all victims and rescue teams is a significant challenge. Moreover, the broadcast burden is further aggravated by multiple rescue teams broadcasting messages simultaneously. To address this issue, Network Coding Based Cooperative (NCBC) broadcast scheme is a promising approach for enhancing broadcast throughput in emergency scenarios. By employing the NCBC broadcast scheme, we show that the broadcast throughput can be significantly improved. We propose a heuristic algorithm for generating optimal deployment of UAVs using network coding strategy and evaluate the broadcast throughput quantitatively. Simulation results show that our approach can ensure user accessibility and yield at least 26.69
In mobile edge computing (MEC), each user chooses and then offloads the task to an edge server, whereas data security is a concern in MEC due to the lack of trust between users and edge servers. Blockchain is introduced to provide a reliable environment for MEC. In blockchain-based MEC, edge servers are used as the nodes in both MEC and blockchain. After processing the users' tasks, the edge servers upload the results and other task-related information to the blockchain. The edge servers simultaneously execute two kind of tasks, i.e., the tasks offloaded by the users and the blockchain tasks. Therefore, the user offloading decision affects the processing latency of MEC tasks, and there is a trade-off between the resource allocation for MEC and blockchain tasks. However, most existing studies optimize the resource allocation for blockchain and MEC individually, which leads to the suboptimal performance of blockchain-based MEC. In this paper, we study the problem of user offloading decision and the computing resource allocation of edge servers for MEC and blockchain tasks, with the objective to minimize the total processing delay of MEC and blockchain tasks. We propose an algorithm for joint computing resource allocation for MEC and blockchain (JMB). Theoretical analysis proves that JMB is a 3.16-approximation algorithm. Simulation results show that JMB can effectively reduce the delay in blockchain-based MEC.
Measuring the similarity between two business process models holds significant importance across various applications. At present, there are many different similarity calculation methods, such as structural similarity based on the graph edit distance(GED), text similarity based on task node description, and behavioral similarity calculation based on path matching. However, existing similarity computation methods cannot produce reliable results since: (1) To apply GED, business process graphs will be simplified to homogeneous graph where the heterogeneity as well as the routing semantics of the business process is removed. (2) To derive comprehensive similarity evaluation, linear weighted sum of different similarity metrics is a common way, but the final result strongly depends on the weighting coefficients that are empirically assigned. In this paper, we fuse multidimensional metrics to compensate for the sole reliance on structural similarity based on GED. To address the limitations of comprehensive evaluation, we propose a novel multidimensional process similarity evaluation method based on the entropy weight method and the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method. We also design a experimental method to verify the effectiveness of our method, leveraging an open source dataset. The experiment shows that our method can better represent the similarity of business process graphs than other methods.
PurposeThis paper aims to propose an incremental graph indexing method based on probabilistic inferences in Bayesian network (BN) for approximate nearest neighbor search (ANNS) that adds unindexed queries into the graph index incrementally.Design/methodology/approachThis paper first uses the attention mechanism based graph convolutional network to embed a social network into the low-dimensional vector space, which could improve the efficiency of graph index construction. To add the unindexed queries into the graph index incrementally, this study proposes to learn the rule-based BN from social interactions. Thus, the dependency relations of unindexed queries and their neighbors are represented, and the probabilistic inferences in BN are then performed.FindingsExperimental results demonstrate that the proposed method improves the search precision by at least 5% and search efficiency by 10% compared to the state-of-the-art methods.Originality/valueThis paper proposes a novel method to construct the incremental graph index based on probabilistic inferences in BN, such that both indexed and unindexed queries in ANNS could be addressed efficiently.
