Xidian University

About: Xidian University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Antenna (radio) & Synthetic aperture radar. The organization has 32099 authors who have published 38961 publications receiving 431820 citations. The organization is also known as: University of Electronic Science and Technology at Xi'an & Xīān Diànzǐ Kējì Dàxué.

Graphene Hybrid Structures for Integrated and Flexible Optoelectronics

Abstract: Graphene (Gr) has many unique properties including gapless band structure, ultrafast carrier dynamics, high carrier mobility, and flexibility, making it appealing for ultrafast, broadband, and flexible optoelectronics To overcome its intrinsic limit of low absorption, hybrid structures are exploited to improve the device performance Particularly, van der Waals heterostructures with different photosensitive materials and photonic structures are very effective for improving photodetection and modulation efficiency With such hybrid structures, Gr hybrid photodetectors can operate from ultraviolet to terahertz, with significantly improved R (up to 109 A W-1 ) and bandwidth (up to 128 GHz) Furthermore, integration of Gr with silicon (Si) complementary metal-oxide-semiconductor (CMOS) circuits, the human body, and soft tissues is successfully demonstrated, opening promising opportunities for wearable sensors and biomedical electronics Here, the recent progress in using Gr hybrid structures toward high-performance photodetectors and integrated optoelectronic applications is reviewed

Interference-Limited Relaying Transmissions in Dual-Hop Cooperative Networks over Nakagami-m Fading

Abstract: In this letter, we investigate the outage performance of dual-hop decode-and-forward (DF) cooperative systems in an interference-limited Nakagami-m fading environment. More specifically, assuming the presence of Nakagami-m faded multiple co-channel interferers at the DF relay and a noisy destination, simple accurate closed-form approximations for the end-to-end outage probability are derived. To this end, moment-based estimators are used to attain the appropriate Nakagami-m fading parameters. Simulation results are presented in order to confirm the accuracy of the proposed approximations.

On conditional diagnosability and reliability of the BC networks

Abstract: An n-dimensional bijective connection network (in brief, BC network), denoted by X n , is an n-regular graph with 2 n nodes and n2 n?1 edges Hypercubes, crossed cubes, twisted cubes, and Mobius cubes all belong to the class of BC networks (Fan and He in Chin J Comput 26(1):84---90, [2003]) We prove that the super connectivity of X n is 2n?2 for n?3 and the conditional diagnosability of X n is 4n?7 for n?5 As a corollary of this result, we obtain the super connectivity and conditional diagnosability of the hypercubes, twisted cubes, crossed cubes, and Mobius cubes

A Triple-Band Ultrathin Metamaterial Absorber With Wide-Angle and Polarization Stability

Abstract: This letter presents a triple-band compact and efficient ultrathin metamaterial absorber with wide-angle and polarization stability. The compact single unit cell includes a metallic background plane, four groups of dipoles lying around a metallic ring connected by four groups of pins, and only 1-mm low-cost dielectric layer. In addition, the main parameters of the designed absorber are investigated and optimized to show that each of three absorption frequency points can be effectively separately adapted, respectively. The simulation results demonstrate that this absorber has good absorption rates and polarization-insensitive characteristic over wide angles of incident waves for both transverse electric (TE) and transverse magnetic (TM) in three frequency bands. The waveguide measurement method is utilized to test the simulated results of three good absorption peaks.

Design of Optimal Petri Net Controllers for Disjunctive Generalized Mutual Exclusion Constraints

Abstract: In this paper, a type of specifications called OR-AND Generalized Mutual Exclusion Constraints (GMEC) for place/transition nets is defined. Such a specification consists of a disjunction of conjunction of several single GMECs, i.e., the requirement is that, at any given time, the controlled system should satisfy at least one set of conjunctive GMECs. We show that a bounded OR-AND GMEC can be enforced by a special control structure composed by a set of AND-GMEC monitor places plus a switcher that determines the current active ones. We also show that such a simple control structure can be modified to ensure maximal permissiveness. This approach can be used in the framework of supervisory control in Petri nets.