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      • DPOAE Biological Feature Modeling and Identity Authentication

        Haijun Lin,Bin Zhang,Xuhui Zhang,Binqiu Duan 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.10

        In this article, a multi-tone signal generated by micro-speaker is adopted as the acoustic stimulation, and two microphones are used to collect the DPOAE data from human ear and background noise respectively. Otoacoustic emission is modeled based on Volterra kernel. The feature of human ear’s DPOAE feature model is extracted intelligently by improved stimulation annealing genetic mixed algorithm. In order to apply this model feature to identification, its feasibility is verified by BP neural network. This provides a new biometric method for identity authentication.

      • KCI등재

        A Hybrid Link Protection Scheme for Ensuring Network Service Availability in Link-state Routing Networks

        Haijun Geng,Han Zhang,Xingang Shi,Zhiliang Wang,Xia Yin,Ju Zhang,Zhiguo Hu,Yong Wu 한국통신학회 2020 Journal of communications and networks Vol.22 No.1

        The internet is playing an increasingly crucial role inboth personal and business activities. In addition, with the emergenceof real-time, delay sensitive and mission-critical applications,stringent network availability requirement is put forward for internetservice providers (ISPs). However, commonly deployed intradomainlink-state routing protocols react to link failures by globallyexchanging link state advertisements and recalculating routingtable, inevitably causing significant forwarding discontinuityafter a failure. Therefore, the loop-free criterion (LFC) approachhas been widely deployed by many ISPs for coping with the singlenetwork component failure scenario in large internet backbones. The success of LFC lies in its inherent simplicity, but this comesat the expense of letting certain failure scenarios go unprotected. To achieve full failure coverage with LFC without incurring significantextra overhead, we propose a novel link protection scheme,hybrid link protection (HLP), to achieve failure resilient routing. Compared to previous schemes, HLP ensures high network availabilityin a more efficient way. HLP is implemented in two stages. Stage one provides an efficient LFC based method (MNP-e). Thecomplexity of the algorithm is less than that of Dijkstra’s algorithmand can provide the similar network availability with LFC. Stage two provides backup path protection (BPP) based on MNP-e,where only a minimum number of links need to be protected, usingspecial paths and packet headers, to meet the network availabilityrequirement. We evaluate these algorithms in a wide spread ofrelevant topologies, both real and synthetic, and the results revealthat HLP can achieve high network availability without introducingconspicuous overhead. HLP not only needs around 10% time ofthat of full protection, but also provides full protection capabilitiesthat full protection provide.

      • 9.73% Efficiency Nonfullerene All Organic Small Molecule Solar Cells with Absorption-Complementary Donor and Acceptor

        Bin, Haijun,Yang, Yankang,Zhang, Zhi-Guo,Ye, Long,Ghasemi, Masoud,Chen, Shanshan,Zhang, Yindong,Zhang, Chunfeng,Sun, Chenkai,Xue, Lingwei,Yang, Changduk,Ade, Harald,Li, Yongfang American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.14

        <P>In the last two years, polymer solar cells (PSCs) developed quickly with n-type organic semiconductor (n-OSs) as acceptor. In contrast, the research progress of nonfullerene organic solar cells (OSCs) with organic small molecule as donor and the n-OS as acceptor lags behind. Here, we synthesized a D-A structured medium bandgap organic small molecule H11 with bithienyl-benzodithiophene (BDTT) as central donor unit and fluorobenzo-triazole as acceptor unit, and achieved a power conversion efficiency (PCE) of 9.73% for the all organic small molecules OSCs with H11 as donor and a low bandgap n-OS IDIC as acceptor. A control molecule H12 without thiophene conjugated side chains on the BDT unit was also synthesized for investigating the effect of the thiophene conjugated side chains on the photovoltaic performance of the p-type organic semiconductors (p-OSs). Compared with H12, the 2D-conjugated H11 with thiophene conjugated side chains shows intense absorption, low-lying HOMO energy level, higher hole mobility and ordered bimodal crystallite packing in the blend films. Moreover, a larger interaction parameter (chi) was observed in the H11 blends calculated from Hansen solubility parameters and differential scanning calorimetry measurements. These special features combined with the complementary absorption of H11 donor and IDIC acceptor resulted in the best PCE of 9.73% for nonfullerene all small molecule OSCs up to date. Our results indicate that fluorobenzotriazole based 2D conjugated p-OSs are promising medium bandgap donors in the nonfullerene OSCs.</P>

      • The Research on Fusion and Diagnosis Method of Multi Soft Fault of Nonlinear Analog Circuit

        Haijun Lin,Jiren Han,Xuhui Zhang,Jingbo Xu,Yunfeng Liu 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.11

        For the single source characteristics of the insufficient problem of nonlinear analog circuit soft fault diagnosis, we propose a new method that is based on dual Wiener core for fault diagnosis of intelligent information optimization fusion[1,2,3,4,5], firstly, the incentive is Gauss white noise, after sampling we obtain the Wiener core of circuit and power which is used from the discrete Wiener core, then use the improved genetic algorithm, make the feature selection and fusion combination as an optimization problem, propose intelligent optimization fusion extraction based on the improved genetic algorithm, the circuit set total Euclidean distance as the objective function optimizes, the different information in feature layer can be organic integration, then use the BP neural network for intelligent diagnosis. Experiments show that the method can effectively improve the accuracy of the diagnosis of nonlinear multiple soft faults.

      • KCI등재

        Analysis and Design Considerations for a High Power Buck Derived LED Driver with Extended Output Voltage and Low Total Harmonic Distortion

        Haijun Lv,Xinke Wu,Junming Zhang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

        In order to reduce the cost, improve the efficiency and simplify the complicated control of existing isolated LED drivers, an improved boundary conduction mode (BCM) Buck ac-dc light emitting diode (LED) driver with extended output voltage and low total harmonic distortion is proposed. With a coupled inductor winding and a stacked output, its output voltage can be elevated to a much higher value when compared to that of the conventional Buck ac-dc converter, without sacrificing the input harmonics and power factor. Therefore, the proposed Buck LED driver can meet the IEC61000-3-2 (Class C) limitation and has a low THD. The operating principle of the topology and the design methodology of the ac-dc LED driver are presented. A 150 W ac-dc prototype was built in the laboratory and it shows that the input current harmonics meet the lighting standard. In addition, the THD is less than 16% at a typical ac input. The peak efficiency is higher than 96.5% at a full load and a normal input.

      • KCI등재

        Optimal Coordination of Intermittent Distributed Generation with Probabilistic Power Flow

        Haijun Xing,Haozhong Cheng,Yi Zhang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.6

        This paper analyzes multiple active management (AM) techniques of active distribution network (ADN), and proposes an optimal coordination model of intermittent distributed generation (IDG) accommodation considering the timing characteristic of load and IDG. The objective of the model is to maximize the daily amount of IDG accommodation under the uncertainties of IDG and load. Various active management techniques such as IDG curtailment, on-load tap changer (OLTC) tap adjusting, voltage regulator (VR) tap adjusting, shunt capacitors compensation and so on are fully considered. Genetic algorithm and Primal-Dual Interior Point Method (PDIPM) is used for the model solving. Point estimate method is used to simulate the uncertainties. Different scenarios are selected for the IDG accommodation capability investigation under different active management schemes. Finally a modified IEEE 123 case is used to testify the proposed accommodation model, the results show that the active management can largely increase the IDG accommodation and penetration.

      • KCI등재

        Determination and Variation of Core Bacterial Community in a Two- Stage Full-Scale Anaerobic Reactor Treating High-Strength Pharmaceutical Wastewater

        ( Haijun Ma ),( Lin Ye ),( Haidong Hu ),( Lulu Zhang ),( Lili Ding ),( Hongqiang Ren ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.10

        Knowledge on the functional characteristics and temporal variation of anaerobic bacterial populations is important for better understanding of the microbial process of two-stage anaerobic reactors. However, owing to the high diversity of anaerobic bacteria, close attention should be prioritized to the frequently abundant bacteria that were defined as core bacteria and putatively functionally important. In this study, using MiSeq sequencing technology, the core bacterial community of 98 operational taxonomic units (OTUs) was determined in a twostage upflow blanket filter reactor treating pharmaceutical wastewater. The core bacterial community accounted for 61.66% of the total sequences and accurately predicted the sample location in the principal coordinates analysis scatter plot as the total bacterial OTUs did. The core bacterial community in the first-stage (FS) and second-stage (SS) reactors were generally distinct, in that the FS core bacterial community was indicated to be more related to a higherlevel fermentation process, and the SS core bacterial community contained more microbes in syntrophic cooperation with methanogens. Moreover, the different responses of the FS and SS core bacterial communities to the temperature shock and influent disturbance caused by solid contamination were fully investigated. Co-occurring analysis at the Order level implied that Bacteroidales, Selenomonadales, Anaerolineales, Syneristales, and Thermotogales might play key roles in anaerobic digestion due to their high abundance and tight correlation with other microbes. These findings advance our knowledge about the core bacterial community and its temporal variability for future comparative research and improvement of the two-stage anaerobic system operation.

      • KCI등재

        Dual‑mode control strategy based on DC‑bus voltage for dual‑active bridge converter in marine electromagnetic transmitter system

        Haijun Tao,Changshun Du,Guopeng Zhang,Zheng Zheng 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.2

        The marine electromagnetic detection method is the main method for the exploration of marine oil and gas resources. At present, the controlled source circuit of the electromagnetic transmitter is a unidirectional flow of electric energy. When the emission electrodes release the stored energy, the energy cannot be fed back, resulting in an increased DC bus and switch device voltages. The stress increases and the filter capacitors and switch devices are burned, which cannot guarantee the long-term reliable operation of the underwater devices body in the deep sea. A dual-active bridge converter is presented for the controlled source circuit of the electromagnetic transmitter. First, the topology, operating principle, and soft-switching constraints are introduced in detail. Then, a dual-mode control strategy is designed. The inductor current stress optimization control is adopted to ensure a steady-state operation, and the univariate extended phase-shifting sliding mode control is applied to achieve fast energy feedback of the inductive load. Simulation and experimental results show that the proposed circuit significantly reduces the bus voltage effect and switch device voltage stress, improves the efficiency and dynamic performance of the system, and satisfies the needs of deep-sea oil and gas resource exploration.

      • KCI등재

        Hot Deformation and Workability of a CrCoNi Medium Entropy Alloy

        Haijun Wang,Zhitong Hu,Junsheng Cao,Shuai Zhang,Tao Cheng,Qingyan Wang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

        Hot compression behaviors of CrCoNi medium entropy alloy are were performed on the Gleeble-3800 thermal simulator inthe strain rate range from 0.01 to 10 s−1 and the temperature range from 800 to 1100 °C. According to the true stress-truestrain curves, the true stress decreases with the decreasing of strain rate and the increasing of deformation temperature. Theexperimental parameters were fitted, and a modified model based on Arrhenius hyperbolic sine was established. Amongthem, material constants such as, n, A, and Q are functions of strain. Meanwhile, the processing map of CrCoNi mediumentropy alloy under different strain conditions are established. Importantly, the optimal domain of apparent flow stabilitycan be determined as the deformation temperature from 900 to 1100 °C and the strain rate from 0.01 to 10 s−1. The resultsindicate that the stability domain of the CrCoN medium entropy alloy has a wider range, and the strain has little effect onits processing performance.

      • KCI등재

        Bond deterioration of corroded steel in two different concrete mixes

        Haijun Zhou,Xuebing Liang,Zeqiang Wang,Xiaolin Zhang,Feng Xing 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.6

        This paper investigated the effects of rebar corrosion on bond performance between rebar and two different concrete mixes (compressive strengths of 20.7 MPa and 44.4 MPa). The specimen was designed as a rebar centrally embedded in a 200 mm concrete cube, with two stirrups around the rebar to supply confinement. An electrochemical accelerated corrosion technique was applied to corrode the rebar. 120 specimens of two different concrete mixes with various reinforcing steel corrosion levels were manufactured. The corrosion crack opening width and length were recorded in detail during and after the corrosion process. Three different loading schemes: monotonic pull-out load, 10 cycles of constant slip loading followed by pullout and varied slip loading followed by pull-out, were carried out on the specimens. The effects of rebar corrosion with two different concrete mixes on corrosion crack opening, bond strength and corresponding slip value, initial slope of bond-slip curve, residual bond stress, mechanical interaction stress, and energy dissipation, were discussed in detail. The mean value and coefficient of variation of these parameters were also derived. It was found that the coefficient of variation of the parameters of the corroded specimens was larger than those with intact rebar. There is also obvious difference in the two different concrete mixes for the effects of rebar corrosion on bond-slip parameters.

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