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Result-consistent counter sampling scheme for coarse-fine TDCs

ELECTRONICS LETTERS 2012年第19期48卷 1195-U43页

作者： Michalik, P. Fernandez, D. Madrenas, J. Univ Politecn Cataluna Dept Engn Elect Barcelona Spain Baolab Microsyst Terrassa Spain

A novel sampling scheme for coarse-fine time-to-digital converters (TDCs), whose architecture commonly comprises a synchronous counter as a coarse part and delay-line based phase interpolator as a fine part, is proposed. The presented approach eliminates any error in the coarse counter and is superior in terms of mean time between failures as well as complexity, area and power consumption in comparison to previously reported solutions.

关键词： Time series analysis Delay lines Check digit schemes Performance of analog-to-digital converters Bit error rate measurement interpolation algorithms Computational complexity

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Three-point Nevanlinna-Pick problem in the polydisc

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PROCEEDINGS OF THE LONDON MATHEMATICAL SOCIETY 2015年第4期111卷 887-910页

作者： Kosinski, Lukasz Jagiellonian Univ Fac Math & Comp Sci Inst Math Lojasiewicza 6 PL-30348 Krakow Poland

In the present article, we show that the same property holds for a three-point Pick problem on polydiscs, that is, the solution may be expressed in terms of 3-complex geodesics. Using this idea, we are able to obtain formulas and a uniqueness theorem for solutions of extremal problems. In particular, we determine a class of rational inner functions that solve the interpolation problem. Possible extensions and further investigations are also discussed.

关键词： NEVANLINNA theory PROBLEM solving GEODESICS (Mathematics) UNIQUENESS (Mathematics) interpolation algorithms

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A LIMITING STRATEGY FOR THE BACK AND FORTH ERROR COMPENSATION AND CORRECTION METHOD FOR SOLVING ADVECTION EQUATIONS

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MATHEMATICS OF COMPUTATION 2016年第299期85卷 1263-1280页

作者： Hu, Lili Li, Yao Liu, Yingjie Georgia Inst Technol Sch Math Atlanta GA 30332 USA NYU Courant Inst Math New York NY USA

We further study the properties of the back and forth error compensation and correction (BFECC) method for advection equations such as those related to the level set method and for solving Hamilton-Jacobi equations on unstructured meshes. In particular, we develop a new limiting strategy which requires another backward advection in time so that overshoots/undershoots on the new time level get exposed when they are transformed back to compare with the solution on the old time level. This new technique is very simple to implement even for unstructured meshes and is able to eliminate artifacts induced by jump discontinuities in derivatives of the solution as well as by jump discontinuities in the solution itself (even if the solution has large gradients in the vicinities of a jump). Typically, a formal second order method for solving a time dependent Hamilton-Jacobi equation requires quadratic interpolation in space. A BFECC method on the other hand only requires linear interpolation in each step, thus is local and easy to implement even for unstructured meshes.

关键词： ADVECTION MATHEMATICAL models HAMILTON-Jacobi equations interpolation algorithms DERIVATIVES (Mathematics) PARTIAL differential equations

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On Fast and Stable Implementation of Clenshaw-Curtis and Fejer-Type Quadrature Rules

ABSTRACT AND APPLIED ANALYSIS

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ABSTRACT AND APPLIED ANALYSIS 2014年第Spe9期000卷 1-10页

作者： Xiang, Shuhuang He, Guo Wang, Haiyong Cent South Univ Sch Math & Stat Changsha 410083 Hunan Peoples R China Huazhong Univ Sci & Technol Sch Math & Stat Wuhan 430074 Hubei Peoples R China

Based upon the fast computation of the coefficients of the interpolation polynomials at Chebyshev-type points by FFT, together with the efficient evaluation of the modified moments by forward recursions or by Oliver's algorithms, this paper presents fast and stable interpolating integration algorithms, by using the coefficients and modified moments, for Clenshaw-Curtis, Fejer's first- and second-type rules for Jacobi weights or Jacobi weights multiplied by a logarithmic function. Numerical examples illustrate the stability, efficiency, and accuracy of these quadratures.

关键词： interpolation algorithms QUADRATURE domains POLYNOMIALS NUMERICAL analysis DIFFERENTIAL equations

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NSE abundance data

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ATOMIC DATA AND NUCLEAR DATA TABLES 2012年第4期98卷 852-861页

作者： Odrzywolek, Andrzej Jagiellonian Univ M Smoluchowski Inst Phys PL-30059 Krakow Poland

A novel method of calculating nuclear statistical equilibrium (NSE) is presented. Basic equations are carefully solved using arbitrary precision arithmetic. A special interpolation procedure is then used to retrieve all abundances using tabulated results for neutrons and protons, together with basic nuclear data. Proton and neutron abundance tables, basic nuclear data, and partition functions for nuclides used in the calculations are provided. A simple interpolation algorithm using pre-calculated p and n abundances tabulated as functions of kT, rho and Y-e is outlined. Unique properties of this method are: (1) ability to pick up out of NSE selected nuclei only, (2) computational time scaling linearly with number of re-calculated abundances, (3) relatively small amount of stored data: only two large tables, (4) slightly faster than solving the NSE equations using traditional Newton-Raphson methods for small networks (few tens of species): superior for huge (800-3000) networks, (5) does not require initial guess: works well on random input, (6) can be tailored to specific application, (7) ability to use third-party NSE solvers to obtain fully compatible tables, and (8) encapsulation of the NSE code for bug-free calculations. A range of applications for this approach is possible: covering tests of traditional NSE Newton-Raphson codes, generating starting values, code-to-code verification, and possible replacement of the old legacy procedures in supernova simulations. (C) 2012 Elsevier Inc. All rights reserved.

关键词： COSMIC abundances EQUILIBRIUM ARITHMETIC NEUTRONS PROTONS NUCLIDES interpolation algorithms NUCLEAR research

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Necessary conditions for interpolating sequences

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BULLETIN OF THE LONDON MATHEMATICAL SOCIETY 1997年第4期29卷 433-442页

作者： Thomas, PJ Université Paul Sabatier UFR M.I.G. 118 route de Narbonne 31062 Toulouse Cedex France

We introduce several successively stronger conditions which are all necessary for a sequence in the unit ball to be interpolating for the space of bounded holomorphic functions, and which all imply Varopoulos' cla... 详细信息

关键词： interpolation algorithms UNIT ball (Mathematics) HOLOMORPHIC functions BOUNDED arithmetics FUNCTIONS of bounded variation

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Fuzzy Modeling Vapor Pressure Deficit to Monitoring Microclimate in Greenhouses

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IFAC-PapersOnLine 2016年第16期49卷 371-374页

作者： Ramos-Fernández, Julio César Balmat, Jean-François Márquez-Vera, Marco Antonio Lafont, Frédéric Pessel, Nathalie Espinoza-Quesada, Eduardo Steed Universidad Politécnica de Pachuca Carr. Pachuca - Cd. Sahagún Km 20 Rancho Luna Ex-Hacienda de Santa Barbara ZempoalaHgo.43830 Mexico Aix Marseille Université Université de Toulon CS 60584 CNRS ENSAM LSIS UMR 7296 Toulon Cedex 9 83041 France

Instrumentation to measure microclimate in greenhouses is a task to developing before starting the identification and control moisture and temperature in greenhouses, a variable which best describe the microclimate and helps prevent fungus and disease risks, is the vapor pressure deficit (VPD), it is measured indirectly by means of two inputs: temperature and humidity, by means the psychrometric chart, and another way is using interpolation models. This paper shows methodology to measure VPD, by using fuzzy modeling type Takagi-Sugeno (T-S). Fuzzy modeling is based on expert and human knowledge, additionally this is combined with mathematical techniques to identify parameters of the antecedents and consequents of IF-THEN fuzzy rules, each IF-THEN fuzzy rule defines a submodel or region of interpolation. In this work, expert knowledge is the information described in psychrometric chart. Modeling learning was performed using air temperature and relative humidity, a set of 8 fuzzy rules was proposed to interpolate the VPD. The results of the fuzzy model are illustrated using measurements of an experimental greenhouse, and was contrasted with a model well known in the literature. The algorithm of fuzzy modelling VPD, was codified in two platform application real time: C to microcontroller and LabVIEWTM, thus it is possible measuring the instantaneous VPD. © 2016

关键词： Fuzzy inference Disease control Fuzzy rules Greenhouses Humidity control Hydrostatic pressure interpolation Risk assessment Algorithm of fuzzy Fuzzy sensors interpolation algorithms Microclimate monitoring Psychrometric charts TakagiSugeno (T S) Temperature and humidities Vapor pressure deficit

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Three-dimensional synthetic turbulence constructed by spatially randomized fractal interpolation

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Physical Review E 2011年第2期84卷 026328-026328页

作者： Zhi-Xiong Zhang Ke-Qi Ding Yi-Peng Shi Zhen-Su She State Key Laboratory of Turbulence and Complex Systems and College of Engineering Peking University Beijing 100871 P.R. China Center for Applied Physics and Technology Peking University Beijing 100871 P.R. China

A spatially randomized fractal interpolation algorithm to construct three-dimensional synthetic turbulence from original coarse field is reported. As in the one-dimensional case by Ding et al.(Phys. Rev. E 82, 036311, 2010), during the fractal interpolation, positions mapping between large and small scale cubes are chosen randomly, and the stretching factors are drawn from a log-Poisson random multiplicative process. A linear combination function defined as the base part in fractal interpolation and a theoretical energy spectrum model for fully developed turbulence are introduced into the procedure. Statistical analysis shows that the synthetic field displays some properties very close to the direct numeric simulated field, such as probability distributions of velocity, velocity gradient, velocity increment, and the anomalous scaling behavior of the longitude velocity structure functions, which follows the SL94 model precisely. After a short time using direct numeric simulation with the synthetic field as initial data, the typical local dynamical structures described by the teardrop shape of the Q-R plane for empirical turbulence can be reproduced.

关键词： interpolation algorithms TURBULENCE APPROXIMATION theory SPEED LARGE eddy simulation models

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Direction-of-Arrival Estimation for Coprime Array Using Compressive Sensing Based Array interpolation

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INTERNATIONAL JOURNAL OF ANTENNAS AND PROPAGATION 2017年第2-16期2017卷 6425067-6425067页

作者： Liu, Aihua Yang, Qiang Zhang, Xin Deng, Weibo Harbin Inst Technol Dept Elect & Informat Engn Harbin 150001 Peoples R China

A method of direction-of-arrival (DOA) estimation using array interpolation is proposed in this paper to increase the number of resolvable sources and improve the DOA estimation performance for coprime array configuration with holes in its virtual array. The virtual symmetric nonuniform linear array (VSNLA) of coprime array signal model is introduced, with the conventional MUSIC with spatial smoothing algorithm (SS-MUSIC) applied on the continuous lags in the VSNLA;the degrees of freedom (DoFs) for DOA estimation are obviously not fully exploited. To effectively utilize the extent of DoFs offered by the coarray configuration, a compressing sensing based array interpolation algorithm is proposed. The compressing sensing technique is used to obtain the coarse initial DOA estimation, and a modified iterative initial DOA estimation based interpolation algorithm (IMCA-AI) is then utilized to obtain the final DOA estimation, which maps the sample covariance matrix of the VSNLA to the covariance matrix of a filled virtual symmetric uniform linear array (VSULA) with the same aperture size. The proposed DOA estimation method can efficiently improve the DOA estimation performance. The numerical simulations are provided to demonstrate the effectiveness of the proposed method.

关键词： Compressed sensing (Signal processing) Antenna arrays interpolation algorithms Computer simulation Analysis of covariance Estimation theory

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Morphing Linear Features Based on Their Entire Structures

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TRANSACTIONS IN GIS 2015年第5期19卷 653-677页

作者： Deng, Min Peng, Dongliang Cent S Univ Dept Geoinformat Changsha Hunan Peoples R China

In this article, a new morphing method is proposed for two linear features at different scales, based on their entire structures (MLBES in abbreviation). First, the bend structures of the linear features are identified by using a constrained Delaunay triangulation (CDT in abbreviation) model and represented by binary bend-structure trees. By matching the independent bends represented by the bend-structure trees, corresponding independent bends are obtained. These corresponding independent bends are further used to match their child bends based on hierarchical bend structures so that corresponding bends are obtained. On this basis, the two linear features are split into pairs of corresponding subpolylines by the start and end points of the corresponding bends. Second, structures of the corresponding subpolylines are identified by the Douglas-Peucker algorithm and represented by binary line generalization trees (BLG-trees in abbreviation). The corresponding subpolylines are split into smaller corresponding subpolylines by matching the nodes of the BLG-trees. Third, the corresponding points are identified by using the linear interpolation algorithm for every pair of corresponding subpolylines. Finally, straight-line trajectories are employed to generate a family of intermediate-scale linear features. By comparison with other methods, it is found that MLBES is accurate and efficient.

关键词： TRIANGULATION interpolation algorithms TRAJECTORIES (Mechanics) TRANSFORMATIONS (Mathematics) VECTOR data

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