VM consolidation has been proposed as an effective solution to improve resource utilization and energy efficiency through VM migration. Improper VM placement during consolidation may cause frequent VM migrations and constant on–off switching of PMs, which can significantly hurt QoS and increase energy consumption. Most existing algorithms on efficient VM placement suffer the problem of easily falling into a sub-optimum prematurely since they are heuristic. Also, they do not achieve a good balance between multiple different goals, such as resource utilization, QoS, and energy efficiency. To address this problem, we propose an effective and efficient VM placement approach called MOEA/D-based VM placement, with the goal of optimizing energy efficiency and resource utilization. We develop an improved MOEA/D algorithm to search for a Pareto-compromise solution for VM placement. Our experiment results demonstrate that the proposed multi-objective optimization (MOO) model and VM placement solution have immense potential as it offers significant cost savings and a significant improvement in energy efficiency and resource utilization under dynamic workload scenarios.

In cloud data centers, determining how to balance the interests of the user and the cloud service provider is a challenging issue. In this study, a task-loading-oriented virtual machine (VM) optimization placement model and algorithm is proposed integrating consideration of both VM placement and the user’s computing requirements. First, the VM placement is modeled as a multi-objective optimization problem to minimize the makespan of the loading tasks, user rental costs, and energy consumption of cloud data centers; then, an improved chaos-elite NSGA-III (CE-NSGAIII) algorithm is presented by casting the logistic mapping-based population initialization (LMPI) and the elite-guided algorithm in NSGA-III; finally, the presented CE-NSGAIII is employed to solve the aforementioned optimization model, and further, through combination of the above sub-algorithms, a CE-NSGAIII-based VM placement method is developed. The experiment results show that the Pareto solution set obtained using the CE-NSGAIII exhibits better convergence and diversity than those of the compared algorithms and yields an optimized VM placement scheme with shorter makespan, less user rental costs, and lower energy consumption.

With the rapid development of the Internet of Things (IoT) and the increase in the frequency of cyberattacks, accurate identification of IoT end devices is critical to their security. Existing identification methods are based on raw, statistical, and deep features of network traffic, each with their own advantages and disadvantages. Raw feature-based methods have difficulty performing feature extraction and insufficient information. As such, the recognition accuracy of statistical feature-based methods is limited by the distinguishment machine learning classifiers, and the deep feature-based methods do not take into account the problem of large differences in traffic samples, which leads to low recognition accuracy in some devices. For this reason, this paper proposes the IoTDI-ImbS method. The method selects the network traffic payload information as the original features and converts them into grayscale images; uses a generative adversarial network-based IoT terminal devices traffic generation (NTGAN) algorithm to generate traffic samples for devices with fewer samples through generative adversarial network to solve the sample imbalance problem; and constructs a ResNet18-BiLSTM model, mining spatial features with ResNet18 and extracting temporal features with BiLSTM to improve recognition accuracy. The experimental results on different sizes of IoT terminal device datasets show that IoTDI-ImbS has performance advantages over other methods in recognition accuracy, better leverages the sample imbalance problem in the dataset, and provides a more effective solution for IoT device recognition. Experimental results on the UNSW and IoT Sentinel dataset demonstrate that IoTDI-ImbS significantly outperforms baseline methods. Specifically, on the UNSW dataset, our method achieves an overall accuracy of 99.1% and an F1-score of 0.985. After integrating the NTGAN module, the identification accuracy for minority classes improved by approximately 3.5%. On the IoT Sentinel dataset, the model maintains a high precision of 98.7%, proving its robustness in diverse IoT environments.

Current methods for identifying unknown Internet of Things (IoT) devices are relatively limited. Most approaches can identify only one type of the unknown IoT devices at a time and with a relatively low accuracy. Herein, we propose a method for unknown IoT device identification (UDI) based on cost-sensitive contrastive loss (CSCL)-Siamese networks and a weighted-voting clustering ensemble (WVE). First, we integrate data visualization techniques with a permutation sample-pairing strategy to generate a complete and nonredundant set of positive–negative sample pairs. Then, we present an algorithm to generate permutation positive–negative sample pairs to provide a rich set of contrastive training data. To overcome the bias in the decision boundary caused by an insufficient number of positive sample pairs, we developed a Siamese network based on CSCL. The CSCL-Siamese network is used to identify known IoT devices and establish an embedded vector database for known IoT devices. Next, we extract the embedding vectors of unknown IoT devices using the trained CSCL-Siamese network and the embedded vector database. Finally, combining weighting factors with a voting ensemble strategy, we develop a UDI algorithm based on a WVE. This presented algorithm integrates the clustering capabilities of multiple unsupervised clustering algorithms to perform clustering on the extracted embedding vectors of unknown IoT devices, thereby enhancing the identification capability of the CSCL-WVE-UDI method. Experimental results demonstrate that the CSCL-WVE-UDI method can effectively identify multiple types of unknown IoT devices at the same time.