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A Testbed of Performance Evaluation for Fingerprint Based WLAN Positioning System

  • Zhao, Wanlong;Han, Shuai;Meng, Weixiao;Zou, Deyue
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.6
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    • pp.2583-2605
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    • 2016
  • Fingerprint positioning is a main stream and key technique for seamless positioning systems. In this paper, we develop a performance evaluation testbed for fingerprint based Wireless Local Area Network (WLAN) positioning system. The testbed consists of positioning server, positioning terminal, Access Point (AP) units, positioning accuracy analysis system and testing scenarios. Different from other testbeds tended to focus on testing in same situation, in the proposed testbed, a couple of scenarios are set to test the positioning system including indoor and outdoor environments. Handset-side positioning mode and network-side positioning mode are provided simultaneously. Variety of motion models, such as static model, low-speed model and high-speed model are considered as well as different positioning algorithms. Finally, some implementation cases are analyzed to verify the credibility of the testbed.

Study on the Temperature Drift Adaptive Compensation Algorithm of a Magneto-Electric Encoder Based on a Simple Neuron

  • Wang, Lei;Hao, Shuang-Hui;Song, Bao-Yu;Hao, Ming-Hui
    • Journal of Power Electronics
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    • v.14 no.6
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    • pp.1254-1262
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    • 2014
  • Magneto-electric encoders have been widely used in industry and military applications because of their good shock resistance, small volume, and convenient data processing. However, the characteristics of a magneto-electric encoder's signal generator and hall sensor changes minimally with temperature variation. These changes cause an angle drift. The main purpose of this study is to construct the compensation system of a neural network and constantly update weight coefficients of temperature correction by finite iteration calculation so that the angle value modified can approach the angle value at the target temperature. This approach is used in adaptive correction of the angle value.

An Approximate Calculation Model for Electromagnetic Devices Based on a User-Defined Interpolating Function

  • Ye, Xuerong;Deng, Jie;Wang, Yingqi;Zhai, Guofu
    • Journal of Magnetics
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    • v.19 no.4
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    • pp.378-384
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    • 2014
  • Optimization design and robust design are significant measures for improving the performance and reliability of electromagnetic devices (EMDs, specifically refer to relays, contactors in this paper). However, the implementation of the above-mentioned design requires substantial calculation; consequently, on the premise of guaranteeing precision, how to improve the calculation speed is a problem that needs to be solved. This paper proposes a new method for establishing an approximate model for the EMD. It builds a relationship between the input and output of the EMD with different coil voltages and air gaps, by using a user-defined interpolating function. The coefficient of the fitting function is determined based on a quantum particle swarm optimization (QPSO) method. The effectiveness of the method proposed in this paper is verified by the electromagnetic force calculation results of an electromagnetic relay with permanent magnet.

Analysis and Optimization of Air-Core Permanent Magnet Linear Synchronous Motors with Overlapping Concentrated Windings for Ultra-precision Applications

  • Li, Liyi;Tang, Yongbin;Ma, Mingna;Pan, Donghua
    • Journal of international Conference on Electrical Machines and Systems
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    • v.2 no.1
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    • pp.16-22
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    • 2013
  • This paper presents the analysis and optimization of air-core permanent magnet linear synchronous motor with overlapping concentrated windings to achieve high thrust density, high thrust per copper losses and low thrust ripple. For the motor design, we adopt equivalent magnetizing current (EMC) method to analyze the magnetic field and give analytical formulae for calculation of motor parameters such as no-load back EMF, dynamic force, thrust density and thrust per copper losses. Further, we proposed a multi-objective optimization by genetic algorithm to search for the optimum parameters. The design optimization is verified by 2-D Finite Element analysis (FEA).

Exogenous Natural Glycoprotein Multiple Mechanisms of Anti-tumor Activity

  • Yuan, Hong-Liang;Liu, Xiao-Lei;Dai, Qi-Chang;Song, Hui
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1331-1336
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    • 2015
  • Natural glycoproteins can induce apoptosis of tumor cells and exert anti-tumor activity by immunomodulatory functions, cytotoxic and anti-inflammation effects, and inhibition of endothelial growth factor. Given their prospects as novel agents, sources of natural antitumor glycoproteins have attracted attention and new research directions in glycoprotein biology are gradually shifting to the direction of cancer treatment and prevention of neoplastic disease. In this review, we summarize the latest findings with regard to the tumor suppressor signature of glycoproteins and underlying regulatory mechanisms.

Microstructure and Magnetic Properties of $Nd_2Fe_{14}B/{\alpha}-Fe$ Nanocomposite Prepared by HDDR Combined with Mechanical Milling

  • Hu, Lianxi;Wang, Erde;Guo, Bin;Shi, Gang
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1286-1287
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    • 2006
  • [ $Nd_2Fe_{14}B/{\alpha}-Fe$ ] nanocomposite powders with a nominal composition of $Nd_{12}Fe_{82}B_6$ were prepared by HDDR combined with mechanical milling. The microstructure was studied by Mossbauer spectrometry and TEM. The magnetic properties were investigated by VSM using bonded magnet samples. The results showed that the annealing temperature had significant influence on both the recombination kinetics and the grain size of the $Nd_2Fe_{14}B$ and ${\alpha}-Fe$ phases, and the bonded magnets presented the best magnetic properties when the nanocomposite powders were prepared by annealing at $760^{\circ}C$ for 30 min.

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Half-Cycle-Waveform-Inversed Single-Carrier Seven-level Sinusoidal Modulation

  • Wu, Fengjiang;Sun, Bo;Zhang, Lujie;Sun, Li
    • Journal of Power Electronics
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    • v.13 no.1
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    • pp.86-93
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    • 2013
  • A half-cycle-waveform inversion based three reference modulations seven-level SPWM (TRM-SPWM) scheme with one carrier is proposed in this paper. To keep the same comparison logics for the modulations and carrier during the negative half cycle and the positive one for the modulations, in the negative half cycle of the modulations, the DC offsets related to the amplitude of the carrier are set on the three modulations, respectively. The seven-level SPWM waveform with dead time thereby is implemented with only one Digital Signal Processor (DSP) without any other attached logic circuit. The basis principle of the proposed TRM-SPWM is analyzed in detail, and the frequency spectrums of the conventional and the proposed schemes are derived and compared with each other through simulation. The DSP based implementation is presented and detailed experimental waveforms verify the accuracy and feasibility of the proposed TRM-SPWM scheme.

Investigation on the failure mechanism of steel-concrete steel composite beam

  • Zou, Guang P.;Xia, Pei X.;Shen, Xin H.;Wang, Peng
    • Steel and Composite Structures
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    • v.20 no.6
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    • pp.1183-1191
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    • 2016
  • The internal crack propagation, the failure mode and ultimate load bearing capacity of the steel-concrete-steel composite beam under the four-point-bend loading is investigated by the numerical simulation. The results of load - displacement curve and failure mode are in good agreement with experiment. In order to study the failure mechanism, the composite beam has been modeled, which part interface interaction between steel and concrete is considered. The results indicate that there are two failure modes: (a) When the strength of the interface is lower than that of the concrete, failure happens at the interface of steel and concrete; (b) When the strength of the interface is higher than that of the concrete, the failure modes is cohesion failure, i.e., and concrete are stripped because of the shear cracks at concrete edge.

Structural behaviors of sustainable hybrid columns under compression and flexure

  • Wu, Xiang-Guo;Hu, Qiong;Zou, Ruofei;Zhao, Xinyu;Yu, Qun
    • Structural Engineering and Mechanics
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    • v.52 no.5
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    • pp.857-873
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    • 2014
  • Structural behaviors of a sustainable hybrid column with the ultra high performance cementitious composites (UHPCC) permanent form under compression and flexure were studied. Critical state and failure stage characters are analyzed for large and small eccentricity cases. A simplified theoretical model is proposed for engineering designs and unified formulas for loading capacity of the hybrid column under compression and flexure loads are derived, including axial force and moment. Non-linear numerical analysis is carried out to verify the theoretical predictions. The theoretical predictions agree well with the numerical results which are verified by the short hybrid column tests recursively. Compared with the traditional reinforced concrete (RC) column, the loading capacity of the sustainable hybrid column is improved significantly due to UHPCC confinements.

Ship information system: overview and research trends

  • Liu, Sheng;Xing, Bowen;Li, Bing;Gu, Mingming
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.3
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    • pp.670-684
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    • 2014
  • Ship Information Systems (SISs) have been one of the main research focuses in ship design and become a multidisciplinary area. With these growing research trends, it is important to consolidate the latest knowledge and information to keep up with the research needs. In this paper, the SIS and its different forms are introduced and discussed. The beginning of this paper discusses the history and evolution of SIS. The next part of this paper focuses on different fields and research areas such as networking technology, information fusion, information decision, message display, ship control in real-time SISs. A Semi-Physical Simulation Platform (SPSIM) designed for SIS research and its running effect through a new Fuzzy-PID fusion algorithm are introduced in this paper then. A brief literature survey and possible future direction concerning each topic is included.