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One-way deep indoor positioning system for conventional GNSS receiver using paired transmitters

NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION 2021年第3期68卷 601-619页

作者： Park, Minhuck Han, Jin-Hee Kim, O-Jong Kim, Jungbeom Kee, Changdon Seoul Natl Univ Inst Adv Machines & Design Seoul South Korea Seoul Natl Univ Dept Aerosp Engn Seoul South Korea Danam Syst Inc Anyang South Korea Samsung Elect Syst LSI Business Hwaseong South Korea

Generally, GNSS-based indoor navigation systems use repeaters or pseudolites. However, these methods are vulnerable to multipath errors and require additional information, including the repeater or pseudolite position. In this study, we propose a novel one-way indoor positioning system using GNSS signal transmitters. Our system uses paired transmitters, each of which broadcasts the same set of satellite signals. The autocorrelation functions of the combined signals are analyzed as the overlap of each individual autocorrelation function. The estimated position can be determined along the track between the transmitters. The multipath error is absorbed by the clock bias and does not cause position bias error. Furthermore, the proposed system can be applied in current commercial GNSS receivers directly. A theoretical analysis of the pseudorange, user position, multipath error, and signal power is included and supported by simulation results. A field test was conducted to confirm the feasibility of the proposed system.

关键词： indoor navigation transmitter auto-correlation function

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A dynamic study of static mixing using on-line image analysis

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POWDER TECHNOLOGY 2002年第2-3期128卷 195-204页

作者： Muerza, S Berthiaux, H Massol-Chaudeur, S Thomas, G Ecole Mines Albi Lab Genie Procedes Solides Divises UMR 2392 CNRS F-81000 Albi France Univ Lyon 1 LAGEP UMR 5007 ESCPE F-69622 Villeurbanne France Ecole Mines St Etienne Ctr SPIN Lab Procedes Milieu Granulaire URA CNRS 2021 F-42100 St Etienne France

In this paper, we try to develop a general methodology for defining and characterising homogeneity at the outlet of any continuous mixer based on auto-correlation of samples. We also emphasize on the necessity of developing on-line non-invasive techniques, as well as systemic model of the powder flow. This is further applied for the case of a static mixer, using a special set-up that allows following the evolution of a typical homogeneity length by image analysis. Mass flow perturbations performed with binary mixtures of aspirin and semolina are studied by examining the variations of the correlograms obtained. The absence of axial dispersion of the signal is finally assessed. (C) 2002 Elsevier Science B.V All rights reserved.

关键词： powder mixing image analysis static mixer auto-correlation function homogeneity

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Unimodular sequence design under frequency hopping communication compatibility requirements

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EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2016年第1期2016卷 1-12页

作者： Ge, Peng Cui, Guolong Kong, Lingjiang Yang, Jianyu Univ Elect Sci & Technol China Sch Elect Engn West Hitech Zone 2006 Xi Yuan Ave Chengdu Sichuan Peoples R China

The integrated design for both radar and anonymous communication has drawn more attention recently since wireless communication system appeals to enhance security and reliability. Given the frequency hopping (FH) communication system, an effective way to realize integrated design is to meet the spectrum compatibility between these two systems. The paper deals with a unimodular sequence design technique which considers optimizing both the spectrum compatibility and peak sidelobes levels (PSL) of auto-correlation function (ACF). The spectrum compatibility requirement realizes anonymous communication for the FH system and provides this system lower probability of intercept (LPI) since the spectrum of the FH system is hidden in that of the radar system. The proposed algorithm, named generalized fitting template (GFT) technique, converts the sequence optimization design problem to a iterative fitting process. In this process, the power spectrum density (PSD) and PSL behaviors of the generated sequences fit both PSD and PSL templates progressively. Two templates are established based on the spectrum compatibility requirement and the expected PSL. As noted, in order to ensure the communication security and reliability, spectrum compatibility requirement is given a higher priority to achieve in the GFT algorithm. This algorithm realizes this point by adjusting the weight adaptively between these two terms during the iteration process. The simulation results are analyzed in terms of bit error rate (BER), PSD, PSL, and signal-interference rate (SIR) for both the radar and FH systems. The performance of GFT is compared with SCAN, CAN, FRE, CYC, and MAT algorithms in the above aspects, which shows its good effectiveness.

关键词： Waveform design Frequency hopping Anonymous communication Spectrum compatibility auto-correlation function

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Long-term room-temperature aging treatment of a bulk metallic glass composite

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JOURNAL OF ALLOYS AND COMPOUNDS 2020年第0期820卷 153165-000页

作者： Xue, Peng Huang, Yongjiang Pauly, Simon Jiang, Songshan Guo, Shu Ning, Zhiliang Sun, Jianfei Harbin Inst Technol State Key Lab Adv Welding & Joining Harbin Peoples R China Harbin Inst Technol Sch Mat Sci & Engn Harbin Peoples R China IFW Dresden Inst Complex Mat Helmholtzstr 20 D-01069 Dresden Germany

In this work, a long-term room-temperature aging treatment of the order of years is applied to a B2 phase-reinforced CuZr-based bulk metallic glass composite (BMGC). Presumably governed by residual stress, B19' CuZr martensitic phase gradually precipitates in the crystals after such long-term aging, while structural relaxation takes place in the glassy matrix, which finally induces precipitation of Cu10Zr7 nanocrystals. Tensile tests prove that these time-dependent structural changes have a measurable effect on deformation behaviors of BMGC. The findings are helpful for understanding the thermodynamic stability and the kinetics of structural evolution of metastable alloys and have useful implications for tailoring the structure and mechanical behavior of BMGCs. (C) 2019 Elsevier B.V. All rights reserved.

关键词： Bulk metallic glass composite Long-term room-temperature aging treatment High-resolution transmission electron microscopy auto-correlation function Mechanical property

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Prediction of the subcellular location of prokaryotic proteins based on the hydrophobicity index of amino acids

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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 2001年第3期28卷 255-261页

作者： Feng, ZP Zhang, CT Tianjin Univ Dept Phys Tianjin 300072 Peoples R China

An algorithm of predicting the subcellular location of prokaryotic proteins is proposed in this paper. In addition to the amino acid composition, the auto-correlation functions based on the hydrophobicity profile of amino acids along the primary sequence of the query protein have been used. Consequently, the best predictive accuracy to date has been achieved. Of the 997 prokaryotic proteins in the database used here, 688 cytoplasmic, 107 extracellular and 202 periplasmic proteins, the overall predictive accuracies are as high as 97.7 and 90.4% in the resubstitution and jackknife tests, respectively, using the hydrophilicity value of Hopp and Woods. The underlying mechanism of the improvement is also discussed. This work would be useful for a systematic analysis of the great amounts of prokaryotic genome sequences. The computer programs used in this paper are available on request via email. (C) 2001 Elsevier Science B.V. All rights reserved.

关键词： amino-acid composition auto-correlation function hydrophobic index subcellular location

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A direct simulation method and lower-bound estimation for a class of gamma random fields with applications in modelling material properties

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PROBABILISTIC ENGINEERING MECHANICS 2017年 47卷 16-25页

作者： Liu, Yong Shields, Michael D. Natl Univ Singapore Dept Civil & Environm Engn Block E1A07-031 Engn Dr 2 Singapore 117576 Singapore Johns Hopkins Univ Dept Civil Engn Baltimore MD 21218 USA

Existing approaches for generating non-Gaussian random fields typically utilize translation process theory that applies a memoryless nonlinear transformation to an underlying Gaussian random field. In the current study, a direct non-translation approach is proposed to generate random fields with a marginal gamma distribution. The proposed approach is based on the additive reproductive property of the gamma distribution;it results in a conceptually simple algorithm that is straightforward to implement in Monte-Carlo simulations. It is demonstrated that an arbitrary marginal gamma distribution is achievable. The resulting auto-correlation functions are non-negative and decreasing functions with a prescribed scale of fluctuation. These characteristics make the proposed non-translation approach suitable for modelling the spatial variability in material properties. The engineering implications of the proposed approach are illustrated through an application example wherein the proposed approach is utilized to generate a spatially varying undrained shear strength field for a two-dimensional plane strain slope, and the stability of the slope is analyzed by the finite element method with Monte-Carlo simulations. Since many material properties have a non-zero lower bound, the three parameter gamma distribution is also discussed, and an asymptotically unbiased and consistent estimate of the lower bound is proposed.

关键词： Non-translation random field Gamma distribution Material properties Spatial variability auto-correlation function Poisson point process

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Mitigating peak side-lobe levels in pulse compression radar using classical orthogonal polynomials

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WIRELESS NETWORKS 2022年第7期28卷 2889-2899页

作者： Thakur, Ankur Saini, Davinder Singh Chandigarh Coll Engn & Technol Dept Elect & Commun Engn Chandigarh 160019 India

Pulse compression radar is used to simultaneously avail the benefits of both short-duration and long-duration pulses. However, the matched filter output has high side-lobe levels along with the main-lobe. These undesired side-lobe levels should be diminished to avoid blind target detection at the radar receiver. This paper defines new radar waveforms to reduce peak side-lobe level (PSL) in pulse compression radar. The proposed waveforms are designed using classical orthogonal polynomials of different orders namely-Legendre, Associated Laguerre, and Chebyshev polynomials. The performance of various polynomials is examined by varying the optimizing parameter gamma and the polynomial which offers maximum PSL reduction is chosen while maintaining constant envelope constraint. Further, the performance of the designed polynomial is observed on the delay-Doppler plane of radar ambiguity function (AF). Simulation outcomes show that the proposed 2nd order Chebyshev orthogonal polynomial (COP) gives higher PSL reduction and superior AF performance than the other polynomials and counterpart methods.

关键词： Ambiguity function auto-correlation function Classical orthogonal polynomials Peak side-lobe level Pulse compression radar

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ROLLING BEARING FAULT DETECTION USING correlation TECHNIQUE

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Applied Mathematics and Mechanics(English Edition) 1992年第7期13卷 617-622页

作者： Xu Yin-ge Yan Yu-ling Peking Administrative Personnel College of Communications Beijing Keio University Japan

It's known that auto-correlation technique is effective in extracting periodical signals from random *** the case of fault monitoring of rolling element bearing,we can't acquire the fault information directly from the original signal because of the difference of signal *** the signal is shown as the wide band random signal in auto-correlation *** this paper,the signal is pre-processed and the results are proved ***,by taking the auto-correlation function we can obtain the determined and comparable *** is very important for establishing the data base of running condition and for detecting the faults.

关键词： auto-correlation function wave shape factor crest factor impulse factor kurtosis factor

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LINEAR VISCOELASTICITY AND IRREVERSIBLE THERMODYNAMICS

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RHEOLOGICA ACTA 1986年第3期25卷 207-213页

作者： DEHARO, ML DELCASTILLO, LF RODRIGUEZ, RF 1.Departamento de Polímeros Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de México Delegación de Coyoacán Apartado Postal 70–360 04510 México D.F. México

The underlying thermodynamic aspects of linear viscoelasticity are discussed. In particular, from the Extended Irreversible Thermodynamics theory we systematically derive the Maxwell model exhibiting its compatibility with thermo-dynamics and assessing its conditions of validity. We also calculate the equilibrium transverse velocity auto-correlation function and the frequency dependent shear viscosity. Nonlinear generalizations of our model are suggested and the possible role of extended thermodynamics in selecting constitutive equations is also discussed.

关键词： Irreversible thermodynamics constitutive equation Maxwell model viscoelasticity auto-correlation function

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A novel method of weakness imbalance fault identification and application in aero-hydraulic pump

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JOURNAL OF VIBROENGINEERING 2019年第1期21卷 52-65页

作者： Yu, Mingyue Cheng, Jincai Pan, Hui Zhang, Runze Lin, Zeli Shenyang Aerosp Univ Shenyang Liaoning Peoples R China Aeromeasurement & Control Technol Res Shanghai Peoples R China

A method of combining auto-correlation and Hilbert envelope analysis is proposed and used to identify weakness imbalance fault of aero-hydraulic pump, the central part of hydraulic system of aircraft. Firstly, the integral and polynomial least square fitting is applied to convert acceleration signal to velocity one;secondly, the Hilbert envelope spectrum of auto-correlation function of velocity signal is obtained and used to identify the weakness imbalance fault of aero-hydraulic pump;finally, the energy ratio of velocity signal is calculated according to Hilbert envelope spectrum for identifying imbalance fault of aero-hydraulic pump by means of easier and more visual method. Meanwhile, the comparing analysis is carried out between traditional research method and proposed new one. The result shows that the weakness imbalance fault of aero-hydraulic pump can be identified and diagnosed effectively and correctly according to the velocity signal whether Hilbert envelope spectrum or calculation energy ratio while direct acceleration signal cannot.

关键词： energy ratio casing vibration signal aero-hydraulic pump auto-correlation function velocity signal

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