Hengyang Normal University

About: Hengyang Normal University is a education organization based out in Hengyang, China. It is known for research contribution in the topics: Graphene & Adsorption. The organization has 1087 authors who have published 1280 publications receiving 13850 citations. The organization is also known as: Hengyang Teachers' College & Héngyáng Shīfàn Xuéyuàn.

A random benchmark suite and a new reaction strategy in dynamic multiobjective optimization

Abstract: In the domain of evolutionary computation, more and more attention has been paid to dynamic multiobjective optimization. Generally, artificial benchmarks are effective tools for the performance evaluation of dynamic multiobjective evolutionary algorithms (DMOEAs). After reviewing existing benchmarks and highlighting their weaknesses, this paper proposes a new benchmark suite to promote the comprehensive testing of algorithms. This proposed benchmark suite has eight random instances in which the randomness is produced by designed random time sequences. Also, this suite introduces challenging but rarely considered characteristics, including diverse features in fitness landscape (e.g. deception, multimodality, and bias) and complex trade-off geometries (e.g. convexity-concavity mixed geometry and disconnected geometry). Empirical studies have shown that the proposed benchmark poses reasonable challenges to DMOEAs in terms of convergence and diversity. Besides, a center matching strategy (CMS) is suggested to track random changes in these problems, which applies the history individual information in a global scope for population prediction. Compared with other reaction strategies, CMS has been demonstrated to be very competitive in dealing with random problems.

Adaptive equalization for high speed optical MIMO wireless communications using white LED

Abstract: Light emitting diode (LED) is one of the most important light sources in the 21st century and has broad prospects in the illumination. Currently, the white LED is used not only for illumination, but also for transmission data. A new technique referred as visible light communication (VLC) is rapidly growing in optical communication. In order to enhance the performance of the communication link, we present optical multiple input and multiple output (MIMO) communication system to achieve high data rate, which can mitigate the shadow effect of indoor communication. Moreover, the MIMO will bring about multi-path effect, which causes inter-symbol interference (ISI) to degrade the performance of the link. Hence, an adaptive equalization technique has been used in the receiver system, which can reduce the ISI when the system is determined to receive symbol. Finally, we have simulated the MIMO system with adaptive equalization. The simulation results show significant improvement in the transmission rate using on off keying (OOK) and the average signal to noise ratio (SNR) in this channel has increased 13.5 dB after equalization.