Novel Dimmable Visible Light Communication Approach Based on Hybrid LACO-OFDM

Sun, Yaqi,Yang, Fang,Gao, Junnan IEEE 2018 Journal of lightwave technology Vol.36 No.20

<P>In this paper, a dimming control approach is proposed for visible light communication based on layered asymmetrically clipped optical orthogonal frequency-division multiplexing (LACO-OFDM) to satisfy different illuminative requirements. The proposed scheme combines LACO-OFDM and negative LACO-OFDM (NLACO-OFDM), which is first introduced to the best of our knowledge. The proportion of the two signals is variable to achieve the desired luminance. The dynamic range is fully exploited by both LACO-OFDM and NLACO-OFDM, resulting in high spectral efficiency. The achievable rate and optimal power allocation are introduced in this paper. Moreover, the achievable rate that varies with the layer number and noise power is also investigated. Simulation results show that the performance of the proposed approach is superior to that of the previous LACO-OFDM-based scheme in terms of power and spectral efficiencies. Meanwhile, the selection of the layer number is dependent on the desired dimming level and noise environment.</P>

Improved Robust Passivity Criteria for Delayed Neural Networks

Yaqi Li,Shuangcheng Sun,Yun Chen 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

This paper investigates the robust passivity problem for neural networks with uncertain system parameters and a time-varying delay. Based on Lyapunov stability theory, ensuring the negative definiteness for the derivatives of the developed Lyapunov-Krasovskii functional (LKF) is necessary in order to derive a passivity criterion. Anegative condition on the cubic polynomial over a certain interval is developed in this paper, which introduces someslack matrices to obtain an advanced negative condition. Taking advantage of this condition, an augmented LKFwith more system state and delay function information, including several augmented vectors and a single-integralbased term, is constructed. Then some improved passivity criteria for delayed neural networks are derived on topof the proposed LKF and the negative condition. Finally, the effectiveness and superiority of the obtained passivitycriteria are validated on two numerical examples.

Effects of two enzyme extracts of Aspergillus niger on green tea aromas

Hui Ni,Sun Hao,Fuping Zheng,Liangzhen Zhang,Bolim Lee,Yaqi Wang,Feng Chen 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.3

Green tea was investigated in terms of its aroma changes induced by two enzyme extracts of Aspergillus niger, i.e., crude enzyme extracted from fermentation using tea stalk medium (CETSM) and crude enzyme yielded in potato dextrose medium. The result showed that the former had significant effects on sensory indexes and volatile constituents, with significant increases in toasty and mushroom notes, while the latter had little influence on the aforementioned indexes. In addition, the volatile constituents were significantly affected; in particular, the contents of cis-3-hexenol, 1-octen-3-ol, eucalyptol, hexanol, and benzaldehyde increased. Furthermore, gas chromatography– olfactometry (GC–O) analysis showed that an increase in 1-octen-3-ol strengthened the mushroom note. These results indicate that CETSM contains some novel enzymes that can modify the aroma profile of green tea.This study also provides valuable information and suggestions to use fermented enzymes to modify food aromas.

Analysis and Design of a Bidirectional High Step-up Active Clamp Flyback Converter for Dielectric Elastomer Actuator

Yang Chen,Yaqi Sun,Mofan Tian,Laili Wang,Haoyuan Jin 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Dielectric elastomer (DE) is a kind of capacitive material that widely used in soft robots’ applications as actuators. To obtain notable deformation, the drive voltage is typically up to several thousand volts and the charging charges must be removed to make it recover. In this paper, a high step-up capacitive load bi-directional flyback converter with active clamp technique is proposed. For the charging process, the effects of increasing high output voltage and parasitic elements in the circuit on the operation of the active clamp circuit are discussed in detail. Wide bandgap devices are used at the secondary side to reduce the parasitic capacitance. The proposed lossless active clamp circuit can absorb the energy in leakage inductance of transformer and achieve zero-voltage-switching (ZVS) over most of the charging process. Besides, the EMI problem caused by leakage inductance of conventional flyback converter is also solved. A prototype with 12V input and 1000V output has been fabricated and compared with a quasi-resonance flyback (QR flyback) at the same working condition. The tested results verify the good performance of the proposed ACF converter.

Fast Finite-time Adaptive Fuzzy Control for Stochastic Nonlinear System

Yixuan Yuan,Junsheng Zhao,Yaqi Gu,Xuejing Zhao,Zong-Yao Sun 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

In this article, we solve the fast finite-time stabilization as well as adaptive fuzzy control design issues for a class uncertain stochastic nonlinear systems. Firstly, a new fast finite-time control scheme is proposed in virtue of generalizing the fast finite-time adaptive control strategy for deterministic systems to the stochastic case. Next, a novel adaptive fuzzy control strategy is developed to simultaneously deal with the stochastic nonlinear systems with completely unknown nonlinearities as well as the disturbances term. Then, stability analysis have been given based on a Jensen’s inequality. Finally, two simulations examples is presented to illustrate the effectiveness of the proposed control scheme.

Catalytic topological insulator Bi₂Se₃ nanoparticles for <i>in</i> <i>vivo</i> protection against ionizing radiation

Zhang, Xiao-Dong,Jing, Yaqi,Song, Shasha,Yang, Jiang,Wang, Jun-Ying,Xue, Xuhui,Min, Yuho,Park, Gyeongbae,Shen, Xiu,Sun, Yuan-Ming,Jeong, Unyong Elsevier 2017 Nanomedicine Vol.13 No.5

<P><B>Abstract</B></P> <P>Bi<SUB>2</SUB>Se<SUB>3</SUB> nanoparticles (NPs) have attracted wide interests in biological and medical applications. Layer-like Bi<SUB>2</SUB>Se<SUB>3</SUB> with high active surface area is promising for free radical scavenging. Here, we extended the medical applications of Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs further to <I>in vivo</I> protection against ionizing radiation based on their superior antioxidant activities and electrocatalytic properties. It was found that Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs can significantly increase the surviving fraction of mice after exposure of high-energy radiation of gamma ray. Additionally, the Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs can help to recover radiation-lowered red blood cell counts, white blood cell counts and platelet levels. Further investigations revealed that Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs behaved as functional free radical scavengers and significantly decreased the level of methylenedioxyamphetamine. <I>In vivo</I> toxicity studies showed that Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs did not cause significant side effects in panels of blood chemistry, clinical biochemistry and pathology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs can significantly increase the surviving fraction of mice up to 70% after Gamma radiation. </LI> <LI> Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs can help to recover radiation-lowered red blood cell counts, white blood cell counts and platelet levels. </LI> <LI> Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs behaved as functional free radical scavengers and significantly decreased the level of methylenedioxyamphetamine. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>Layer-like Bi<SUB>2</SUB>Se<SUB>3</SUB> with high active surface area can protect mice against ionizing radiation based on their superior antioxidant activities and electrocatalytic properties. Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs can significantly increase the surviving fraction of mice up to 70% after exposure of high-energy radiation of gamma ray. Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs behaved as functional free radical scavengers and significantly decreased the level of methylenedioxyamphetamine. <I>In vivo</I> toxicity studies showed that Bi<SUB>2</SUB>Se<SUB>3</SUB> NPs did not cause significant side effects in panels of blood chemistry, clinical biochemistry and pathology.</P> <P>[DISPLAY OMISSION]</P>