Harbin Engineering University

About: Harbin Engineering University is a education organization based out in Harbin, Heilongjiang, China. It is known for research contribution in the topics: Control theory & Computer science. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

Cooperative Wireless Energy Harvesting and Spectrum Sharing in 5G Networks

Abstract: In this paper, we propose a novel best cooperative mechanism (BCM) for wireless energy harvesting and spectrum sharing in 5G networks. Data transfer and energy harvesting are finished in the designed timeslot mode. In the proposed BCM, secondary users (SUs) harvest energy from both ambient signals and primary user’s (PU’s) signals. In addition, the SU’s can act as relay for PUs and harvest energy from PU signals simultaneously. The proposed mechanism allows optimal time duration for data transfer within the timeslot. We formulate an optimization problem based on the proposed BCM with an objective to maximize throughput of PUs and SUs with constraints on data rate and energy harvest save ratios. The effectiveness of the proposed cooperative mechanism is verified by simulations, and it is considered as an important stepping stone for future research in this domain.

Some spectral properties of uniform hypergraphs

Abstract: For a $k$-uniform hypergraph $H$, we obtain some trace formulas for the Laplacian tensor of $H$, which imply that $\sum_{i=1}^nd_i^s$ ($s=1,\ldots,k$) is determined by the Laplacian spectrum of $H$, where $d_1,\ldots,d_n$ is the degree sequence of $H$. Using trace formulas for the Laplacian tensor, we obtain expressions for some coefficients of the Laplacian polynomial of a regular hypergraph. We give some spectral characterizations of odd-bipartite hypergraphs, and give a partial answer to a question posed by Shao et al \cite{ShaoShanWu}. We also give some spectral properties of power hypergraphs, and show that a conjecture posed by Hu et al \cite{HuQiShao} holds under certain conditons.

Self-assembly of ZnO nanoparticles into hollow microspheres via a facile solvothermal route and their application as gas sensor

Abstract: In order to enrich the variety of zinc oxide (ZnO), well-defined ZnO hollow microspheres self-assembled by a mass of nanoparticles were successfully synthesized through a facile solvothermal process employing polyethylene glycol 400 (PEG 400) as the solvent. PEG 400 played a crucial role as a nonionic surfactant in the formation of the ZnO hollow spheres. The plausible formation mechanism was described as self-assembly of nanoparticles, Ostwald ripening, and crystal growth process. The gas sensing performances of the ZnO hollow spheres have been investigated carefully. The results indicate that the prepared ZnO hollow sphere architecture is a promising material for gas sensing applications. In addition, hollow structures have attracted considerable attention because of their unique properties and wide potential applications. The present chemical technique is expected to be useful to prepare other metal oxides or hollow architectures.