gaochao xu

Dr. gaochao xu


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
6 November 2020 in IEEE Transactions on Vehicular Technology
Verified
Journal Article
Closed access
YLYang Li
Yang Li
GXgaochao xu
gaochao xu
KYKun Yang
Kun Yang
JGJiaqi Ge
Jiaqi Ge
PLPeng Liu
Peng Liu
JZJin Zhenjun
Jin Zhenjun
In order to improve resource utilization and network capacity, we propose the Device-to-Device (D2D) enabled Mobile Edge Computing (MEC) system, where multiple Smart Devices (SDs) transmit the offloading data to the MEC server with the help of wireless access point (WAP) selected from multiple WAPs. The SD uses the chosen WAP as the communication relay between the MEC server and itself. Aimed to minimize the total energy consumption of the system and satisfy the SDs‘ demand on delay, we jointly optimize relay selection and resource allocation in D2D-enabled MEC system. The problem is formulated as an integer-mixed non-convex optimization problem which is a NP-hard problem. We thus propose a two-phase optimization algorithm that jointly optimizes relay selection policy and resource allocation strategy. In first phase, the original problem is converted into a convex optimization problem by using convex optimization techniques, and the optimal relay selection policy can be achieved by solving the relay selection problem. After obtaining the relay selection policy, the original problem is transformed into a resource allocation problem solved by leveraging the Lagrange Method in the second phase. Furthermore, the proposed algorithm is a low-complexity algorithm which is associated with the root finding method. The optimal relay selection policy and resource allocation strategy can be found in polynomial time. The extensive simulation results are provided to indicate that the D2D-enabled MEC system achieves remarkable results in energy saving. Compared with other baseline methods, our proposed algorithm can not only achieve the optimal solution with less time cost, but also improve the energy efficiency and network capacity.

1 January 2013 in The Scientific World Journal
Verified
Journal Article
Open access
PDF file
JZJia Zhao
Jia Zhao
YDYan Ding
Yan Ding
GXgaochao xu
gaochao xu
LHLiang Hu
Liang Hu
YDYushuang Dong
Yushuang Dong
XFXiaodong Fu
Xiaodong Fu
Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy) of live VM migration for power saving and load balancing. We propose a novel approach MOGA‐LS, which is a heuristic and self‐adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA). This paper has presented the specific design and implementation of MOGA‐LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA) idea into MOGA‐LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long‐term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA‐LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high‐effective and meaningful.

1 January 2014 in The Scientific World Journal
Verified
Journal Article
Open access
YDYu-Shuang Dong
Yu-Shuang Dong
GXgaochao xu
gaochao xu
XFXiao-Dong Fu
Xiao-Dong Fu
The cloud platform provides various services to users. More and more cloud centers provide infrastructure as the main way of operating. To improve the utilization rate of the cloud center and to decrease the operating cost, the cloud center provides services according to requirements of users by sharding the resources with virtualization. Considering both QoS for users and cost saving for cloud computing providers, we try to maximize performance and minimize energy cost as well. In this paper, we propose a distributed parallel genetic algorithm (DPGA) of placement strategy for virtual machines deployment on cloud platform. It executes the genetic algorithm parallelly and distributedly on several selected physical hosts in the first stage. Then it continues to execute the genetic algorithm of the second stage with solutions obtained from the first stage as the initial population. The solution calculated by the genetic algorithm of the second stage is the optimal one of the proposed approach. The experimental results show that the proposed placement strategy of VM deployment can ensure QoS for users and it is more effective and more energy efficient than other placement strategies on the cloud platform.

23 April 2024 in Entropy
Verified
Journal Article
Open access
PDF file
YLYong Li
Yong Li
GXgaochao xu
gaochao xu
XMxutao Meng
xutao Meng
炜杜炜 杜
炜 杜
XRxianglin Ren
xianglin Ren
In the realm of federated learning (FL), the exchange of model data may inadvertently expose sensitive information of participants, leading to significant privacy concerns. Existing FL privacy-preserving techniques, such as differential privacy (DP) and secure multi-party computing (SMC), though offering viable solutions, face practical challenges including reduced performance and complex implementations. To overcome these hurdles, we propose a novel and pragmatic approach to privacy preservation in FL by employing localized federated updates (LF3PFL) aimed at enhancing the protection of participant data. Furthermore, this research refines the approach by incorporating cross-entropy optimization, carefully fine-tuning measurement, and improving information loss during the model training phase to enhance both model efficacy and data confidentiality. Our approach is theoretically supported and empirically validated through extensive simulations on three public datasets: CIFAR-10, Shakespeare, and MNIST. We evaluate its effectiveness by comparing training accuracy and privacy protection against state-of-the-art techniques. Our experiments, which involve five distinct local models (Simple-CNN, ModerateCNN, Lenet, VGG9, and Resnet18), provide a comprehensive assessment across a variety of scenarios. The results clearly demonstrate that LF3PFL not only maintains competitive training accuracies but also significantly improves privacy preservation, surpassing existing methods in practical applications. This balance between privacy and performance underscores the potential of localized federated updates as a key component in future FL privacy strategies, offering a scalable and effective solution to one of the most pressing challenges in FL.

14 May 2025 in IEEE Internet of Things Journal
Verified
Journal Article
Closed access
LLlong li
long li
GXGaochao Xu
Gaochao Xu
ZLZiqi Liu
Ziqi Liu
GXgaochao xu
gaochao xu
XMXianqiu Meng
Xianqiu Meng
XMXiangyu Meng
Xiangyu Meng
With the increasing demand for real-time data processing in disaster relief and remote areas, autonomous aerial vehicles (AAVs)-assisted mobile-edge computing (MEC) systems have emerged as a promising solution by providing power and computing resources to user devices (UDs). This article introduces a multicluster fair service AAV-assisted wireless powered MEC system aimed at addressing the challenges between energy efficiency and fair service. We formulate a long-term multiobjective energy efficiency optimization problem (LMEEOP) to tradeoff UD energy consumption, AAV energy consumption, and offline rate. However, this problem is a mixed integer nonlinear programming problem and difficult to solve. Thus, we propose a trajectory limited online joint optimization approach (TLOJOA), which decomposes LMEEOP into three subproblems: 1) AAV flight trajectory design; 2) offloading decision generation; and 3) resource allocation. Specifically, a Self-Attention combined proximal policy optimization (PPO) algorithm captures long-range dependencies to balance energy consumption and offline rate. Additionally, a fast offloading strategy generation algorithm with offloading importance ranking is proposed to improve UD energy efficiency. Finally, the AAV flight trajectory and offloading decision are combined to achieve efficient resource allocation. The proposed approach provides a robust solution for improving multicluster fair service and energy efficiency optimization in AAV-assisted MEC systems, especially for mission-critical scenarios with constrained resources. Simulation results validate that the proposed approach can achieve outstanding system performance compared to other benchmark approaches, especially in fairness of service.

20 December 2020 in Future Internet
Verified
Journal Article
Open access
PDF file
LLlong li
long li
GXgaochao xu
gaochao xu
PLPeng Liu
Peng Liu
YLYang Li
Yang Li
JGJiaqi Ge
Jiaqi Ge
With the rapid popularity of mobile devices (MDs), mobile edge computing (MEC) networks and wireless power transmission (WPT) will receive more attention. Naturally, by integrating these two technologies, the inherent energy consumption during task execution can be effectively reduced, and the collected energy can be provided to charge the MD. In this article, our research focuses on extending the battery time of MDs by maximizing the harvested energy and minimizing the consumed energy in the MEC–WPT system, which is formulated as a residual energy maximization problem and also a non-convex optimization problem. On the basis of study on maximizing the residual energy under multi-users and multi-time blocks, we propose an effective jointly optimization method (i.e., jointly optimize the energy harvesting time, task-offloading time, task-offloading size and the MDs’ CPU frequency), which combines the convex optimization method and the augmented Lagrangian to solve the residual energy maximum problem. We leverage Time Division Multiple Access (TMDA) mode to coordinate computation offloading. Simulation results show that our scheme has better performance than the benchmark schemes on maximizing residual energy. In particular, our proposed scheme is outstanding in the failure rate of multiple MDs and can adapt to the task size to minimize the failure rate.