Efficient Message Scheduling for WDM Optical Networkswith Minimizing Flow Time

Xiaohong Huang,Maode Ma 한국통신학회 2004 Journal of communications and networks Vol.6 No.2

Efficient Message Scheduling for WDM Optical Networks with Minimizing Flow Time

Huang, Xiaohong,Ma, Maode The Korea Institute of Information and Commucation 2004 Journal of communications and networks Vol.6 No.2

In this paper, we propose an efficient sequencing technique, namely minimum Row time scheduling (MFTS), to manage variable-Iength message transmissions for single-hop passive starcoupled WDM optical networks. By considering not only the message length but also the state of the receivers and the tuning latency, the proposed protocol can reduce the average delay of the network greatly. This paper also introduces a new channel assignment technique latency minimizing scheduling (LMS), which aims to reduce the scheduling latency. We evaluate the proposed algorithm, using extensive discrete-event simulations, by comparing its performance with shortest job first (SJF) algorithm. We find that significant improvement in average delay could be achieved by MFTS algorithm. By combining the proposed message sequencing technique with the channel selection technique, the performance of the optical network could be further improved.

Modulating charge transport characteristics of bis-azaisoindigo-based D-A conjugated polymers through energy level regulation and side chain optimization

Huang, Kaiqiang,Zhao, Xue,Du, Yuchang,Kim, Sanghyo,Wang, Xiaohong,Lu, Hongbo,Cho, Kilwon,Zhang, Guobing,Qiu, Longzhen The Royal Society of Chemistry 2019 Journal of Materials Chemistry C Vol.7 No.25

<P>Six donor-acceptor (D-A) conjugated polymers, P1-P6, based on the novel electron acceptors bis-isoindigo (BIID) and bis-azaisoindigo (BAID), were designed and synthesized for solution-processed organic field-effect transistors with high-performance optical and electrical properties. Energy level regulation was achieved by incorporation of nitrogen and fluorine heteroatoms and side chain optimization to reduce side chain density and extend branching point positions. Both the hole (<I>μ</I>h) and electron mobilities (<I>μ</I>e) significantly increased from P1 to P6, and there was an obvious transition from hole-dominated ambipolar charge transport behavior to highly-balanced ambipolar behavior. Since aza-substitution strengthened the electron-deficient property of the acceptor units, the entire molecular skeleton of BAID-based polymers has a high electron affinity and a low-lying lowest unoccupied molecular orbital (LUMO) level according to ultraviolet photoelectron spectroscopy (UPS) and cyclic voltammetry (CV) measurements. The <I>μ</I>e of BAID-based polymers is an order of magnitude higher than that of BIID-based polymers. In addition, side chain optimization was shown to significantly influence intermolecular interactions and supramolecular self-assembly. The stepwise reduction of the π-π stacking distances of P1-P6 calculated by GIXRD curves supports this conclusion. Finally, in P6 (PBAID3-2FBT), a maximum absorption wavelength (<I>λ</I>max) was observed at 797 nm, a low optical band gap (<I>E</I>g) of 1.27 eV, a low LUMO level of −3.90 eV, and an average <I>μ</I>h and <I>μ</I>e of 1.31 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>. This paper offers an available molecular design strategy to achieve highly-balanced and high-performance ambipolar charge carrier transport D-A conjugated polymers.</P>

Z-domain modeling of peak current mode control for full-bridge DC-DC buck converters

Wang, Xiaohong,Huang, Qisong,Zhang, Bo,Chen, Di,Guan, Quanxue The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.1

Traditional local-averaged state-space modeling for peak current mode (PCM) controls fails to explain the subharmonic oscillation phenomenon when the spectrum is higher than half of the switching frequency. To address this problem, this paper presents a small-signal modeling method in the z-domain, and builds a discrete linear model for the current loop of a full-bridge DC-DC converter. This discrete model is converted into a second-order continuous model that is able to represent the system performance with a wider frequency range. A frequency-domain analysis shows that this model can be used to explain the subharmonic oscillations and unstable characteristics. This provides an engineering guideline for the practical design of slope compensation. The effectiveness of the proposed modeling method has been verified by simulation and experimental results with a prototype working in the Buck mode.

Optimal Sizing and Energy Management of Hybrid Energy Storage System for High-Speed Railway Traction Substation

Tang Sida,Huang Xiaohong,Li Qunzhan,Yang Naiqi,Liao Qinyu,Sun Ke 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

Traction power fl uctuations have economic and environmental eff ects on high-speed railway system (HSRS). The combination of energy storage system (ESS) and HSRS shows a promising potential for utilization of regenerative braking energy and peak shaving and valley fi lling. This paper studies a hybrid energy storage system (HESS) for traction substation (TS) which integrates super-capacitor (SC) and vanadium redox battery (VRB). According to the characteristics of the traction load under actual operating conditions, an energy management strategy with fi xed-period control (FPC) is proposed, which fully leverages the periodicity and regularity of HSRS operation. To achieve the optimal size, economic feasibility is selected as the optimization objective, which is fully assessed in terms of Net Present Value (NPV). The optimization constraints are formulated in which the Discrete Fourier Transform (DFT) is performed for power allocation between SC and VRB. Besides, an improved mutation-based particle swarm optimization (IMBPSO) is proposed to effi ciently solve the optimization and enhance convergence performance. Finally, combined with the measured traction load data, the eff ectiveness of the FPC energy management strategy is verifi ed and the optimal scale of the HESS is provided.

Compound K attenuates hyperglycemia by enhancing glucagon-like peptide-1 secretion through activating TGR5 via the remodeling of gut microbiota and bile acid metabolism

Tian, Fengyuan,Huang, Shuo,Xu, Wangda,Chen, Lan,Su, Jianming,Ni, Haixiang,Feng, Xiaohong,Chen, Jie,Wang, Xi,Huang, Qi The Korean Society of Ginseng 2022 Journal of Ginseng Research Vol.46 No.6

Background: Incretin impairment, characterized by insufficient secretion of L-cell-derived glucagon-like peptide-1 (GLP-1), is a defining step of type 2 diabetes mellitus (T2DM). Ginsenoside compound K (CK) can stimulate GLP-1 secretion; however, the potential mechanism underlying this effect has not been established. Methods: CK (40 mg/kg) was administered orally to male db/db mice for 4 weeks. The body weight, oral glucose tolerance, GLP-1 secretion, gut microbiota sequencing, bile acid (BA) profiles, and BA synthesis markers of each subject were then analyzed. Moreover, TGR5 expression was evaluated by immunoblotting and immunofluorescence, and L-cell lineage markers involved in L-cell abundance were analyzed. Results: CK ameliorated obesity and impaired glucose tolerance in db/db mice by altering the gut microbiota, especially Ruminococcaceae family, and this changed microbe was positively correlated with secondary BA synthesis. Additionally, CK treatment resulted in the up-regulation of CYP7B1 and CYP27A1 and the down-regulation of CYP8B1, thereby shifting BA biosynthesis from the classical pathway to the alternative pathway. CK altered the BA pool by mainly increasing LCA and DCA. Furthermore, CK induced L-cell number expansion leading to enhanced GLP-1 release through TGR5 activation. These increases were supported by the upregulation of genes governing GLP-1 secretion and L-cell differentiation. Conclusions: The results indicate that CK improves glucose homeostasis by increasing L-cell numbers, which enhances GLP-1 release through a mechanism partially mediated by the gut microbiota-BA-TGR5 pathway. Therefore, that therapeutic attempts with CK might be useful for patients with T2DM.

Research on New Nylon-6 Nanocomposites with Flame Retardancy

Jinliang Qiao,Xiaohong Zhang,Yiqun Liu,Weifu Dong,Qingguo Wang,Hua Gui,Jianming Gao,Zhihai Song,Jinmei Lai,Fan Huang 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.10

A Secure and Efficient Message Authentication Scheme for Vehicular Networks based on LTE-V

( Cheng Xu ),( Xiaohong Huang ),( Maode Ma ),( Hong Bao ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.6

Vehicular networks play an important role in current intelligent transportation networks and have gained much attention from academia and industry. Vehicular networks can be enhanced by Long Term Evolution-Vehicle (LTE-V) technology, which has been defined in a series of standards by the 3rd Generation Partnership Project (3GPP). LTE-V technology is a systematic and integrated V2X solution. To guarantee secure LTE-V communication, security and privacy issues must be addressed before the network is deployed. The present study aims to improve the security functionality of vehicular LTE networks by proposing an efficient and secure ID-based message authentication scheme for vehicular networks, named the ESMAV. We demonstrate its ability to simultaneously support both mutual authentication and privacy protection. In addition, the ESMAV exhibit better performance in terms of overhead computation, communication cost, and security functions, which includes privacy preservation and non-frameability.

Drying performance and energy consumption of Camellia oleifera seeds under microwave-vacuum drying

Dongyan Zhang,Dan Huang,Xiyang Zhang,Hangyi Zhao,Guiliang Gong,Xiaohong Tang,Lijun Li 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.7

Microwave-vacuum drying performance and energy consumption of Camellia oleifera seeds were studied in this paper. The effects of microwave power, vacuum pressure and loading quantity were evaluated and discussed. Orthogonal experiments were also conducted to optimize the drying process. A new drying model based on the weibull distribution model was developed. Results showed that the microwave-vacuum drying process was dominated by internal water diffusion and surface water evaporation. As the microwave power and vacuum pressure increased and the loading quantity decreased, the drying time and energy consumption both decreased. However, too low or too high microwave power would increase the energy consumption. The optimal microwave-vacuum drying conditions were found to be a loading quantity of 150 g, a microwave power of 350 W and a vacuum pressure of 0.09 MPa. The developed drying model and the calculated scale and shape parameter were all consistent with experimental results.

Adaptive OFDMA with Partial CSI for Downlink Underwater Acoustic Communications

Yuzhi Zhang,Yi Huang,Lei Wan,Shengli Zhou,Xiaohong Shen,Haiyan Wang 한국통신학회 2016 Journal of communications and networks Vol.18 No.3

Multiuser communication has been an important researcharea of underwater acoustic communications and networking. This paper studies the use of adaptive orthogonal frequencydivisionmultiple access (OFDMA) in a downlink scenario, wherea central node sends data to multiple distributed nodes simultaneously. In practical implementations, the instantaneous channelstate information (CSI) cannot be perfectly known by the centralnode in time-varying underwater acoustic (UWA) channels, due tothe long propagation delays resulting from the low sound speed. In this paper, we explore the CSI feedback for resource allocation. An adaptive power-bit loading algorithm is presented, which assignssubcarriers to different users and allocates power and bits toeach subcarrier, aiming to minimize the bit error rate (BER) underpower and throughput constraints. Simulation results show considerableperformance gains due to adaptive subcarrier allocationand further improvement through power and bit loading, as comparedto the non-adaptive interleave subcarrier allocation scheme. In a lake experiment, channel feedback reduction is implementedthrough subcarrier clustering and uniform quantization. Althoughthe performance gains are not as large as expected, experiment resultsconfirm that adaptive subcarrier allocation schemes based ondelayed channel feedback or long term statistics outperform theinterleave subcarrier allocation scheme.