No abstract

With the popular use of IoT devices, edge computing has been widely applied in the Internet of things (IoT) and regarded as a promising solution for its wide distribution, decentralization, low latency. At the same time, in response to the massive computing data and intelligent requirements of various applications in the IoT, artificial intelligence (AI) technology has also achieved rapid development. As a result, edge intelligence (EI) for the Internet of Things has attracted widespread attention. Driven by the requirement that making full use of data, machine learning (ML) models trained in EI are usually shared. However, there may be some security and privacy issues due to the openness and heterogeneity of edge intelligence. How to ensure flexible data access and data security as well as the accountability for edge nodes and users in EI model sharing have become important issues. In this article, we propose a Ciphertext Policy Attribute Based Proxy Re-encryption (CP-ABPRE) scheme with accountability to address the security and privacy issues in EI model sharing. In our scheme, a user can delegate the access right to others to make model access more flexible. Furthermore, each entity that may need to be held accountable is embedded a unique ID to achieve traceability. Finally, security analysis and performance evaluation are given to prove that our scheme is CPA secure and does not lose much efficiency with more features.

This article presents a pattern-and frequency-reconfigurable antenna based on movable liquid metal. The proposed antenna mainly consists of a printed three-element Yagi-Uda structure whose two parasitic elements are loaded with slots in the middle. Six movable liquid metal poles are filled in the microfluidic channels, which adhered to the surface of the three radiating arms of the Yagi-Uda antenna. By moving these liquid metal poles, the slots can be shorted or opened and the equivalent electrical lengths of the director and fed-dipole can be changed, thus adjusting the antenna in radiation pattern and frequency. As a result, this antenna can work at different states, which are mainly classified into five modes. To verify this design concept, a prototype of the proposed antenna is fabricated and measured. The measured results indicate that the antenna can operate in the frequency range from 1.52 to 3.2 GHz, and the peak gain can reach 7.3 dBi.

In this study, a broadband and high gain dielectric‐rod end‐fire antenna are proposed for applications on both the K and Ka bands. By employing the double‐ridged waveguide (DRW) feeding structure which is composed of a coaxial line to tapered DRW transition, a parabolic tapered DRW, and a parabolic‐tapered flared parallel waveguide section, the impedance bandwidth of this proposed antenna is broadened to 84.5%. The dielectric‐rod with the double circular truncated cone structure acted as the main radiator of the proposed antenna is adopted to achieve higher gains and lower side‐lobe levels as compared to the traditional circular cone dielectric‐rod, while the four‐wedges structure inserted in the waveguide is developed as the matching section of the dielectric‐rod to further improve the impedance matching. The measured results show that this antenna can be operated in 17.9–44.1 GHz, and the measured gain changes from 9.9 to 15.5 dBi. Moreover, the radiation patterns are demonstrated with observed end‐fire characteristic in the overall operating band.

No abstract