scholarly journals Sinusoidal Frequency Modulation Fourier-Bessel Series for Multicomponent SFM Signal Estimation and Separation

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Qi-fang He ◽  
Qun Zhang ◽  
Ying Luo ◽  
Li Sun
Keyword(s):  
Frequency Modulation ◽  
Performance Comparison ◽  
Estimation Methods ◽  
Physical Parameters ◽  
Sliding Windows ◽  
Instantaneous Approximation ◽  
Bessel Transform ◽  
The Individual ◽  
Computation Load ◽  
Global Data

Multicomponent sinusoidal frequency modulated (SFM) signals are widely used in radar, acoustics, and biomedicine. The instantaneous frequency (IF) characterizes important physical parameters of the real applications. In this paper, a sinusoidal frequency modulation Fourier-Bessel (SFMFB) series is defined for IF estimation. It provides the signal decomposition on the Bessel function basis with a finer resolution, which proposes an extension of the performance and the applicability of the classic Fourier-Bessel transform (FBT). Based on the property analysis of the SFMFB series, an algorithm of IF estimation and signal separation is introduced. Unlike the existing estimation methods which apply sliding windows to make an instantaneous approximation, the proposed method uses the global data, which provides a longer period gain, therefore achieving a better estimation performance. Moreover, considering that most estimation methods are invalid in multicomponent separation, the individual signals are well separated by the proposed algorithm, which facilitates the further monocomponent analysis. A performance comparison between the proposed method, the FBT, and another recently proposed sinusoidal frequency modulation Fourier transform (SFMFT) is also provided. Simulation results indicate that the proposed method outperforms the existing methods in estimation precision and computation load, and it is free of interference which exists in SFMFT.

A Spectrum-Adaptive Decomposition Method for Effective Atomic Number Estimation Using Dual Energy CT

2020 ◽  
Vol 2020 (14) ◽  
pp. 293-1-293-7
Author(s):  
Ankit Manerikar ◽  
Fangda Li ◽  
Avinash C. Kak
Keyword(s):  
Atomic Number ◽  
Decomposition Method ◽  
Traditional Approach ◽  
Effective Atomic Number ◽  
Dual Energy ◽  
Performance Comparison ◽  
Estimation Methods ◽  
Dual Energy Ct ◽  
Projection Data ◽  
X Ray

Dual Energy Computed Tomography (DECT) is expected to become a significant tool for voxel-based detection of hazardous materials in airport baggage screening. The traditional approach to DECT imaging involves collecting the projection data using two different X-ray spectra and then decomposing the data thus collected into line integrals of two independent characterizations of the material properties. Typically, one of these characterizations involves the effective atomic number (Zeff) of the materials. However, with the X-ray spectral energies typically used for DECT imaging, the current best-practice approaches for dualenergy decomposition yield Zeff values whose accuracy range is limited to only a subset of the periodic-table elements, more specifically to (Z < 30). Although this estimation can be improved by using a system-independent ρe — Ze (SIRZ) space, the SIRZ transformation does not efficiently model the polychromatic nature of the X-ray spectra typically used in physical CT scanners. In this paper, we present a new decomposition method, AdaSIRZ, that corrects this shortcoming by adapting the SIRZ decomposition to the entire spectrum of an X-ray source. The method reformulates the X-ray attenuation equations as direct functions of (ρe, Ze) and solves for the coefficients using bounded nonlinear least-squares optimization. Performance comparison of AdaSIRZ with other Zeff estimation methods on different sets of real DECT images shows that AdaSIRZ provides a higher output accuracy for Zeff image reconstructions for a wider range of object materials.

scholarly journals First Cost Calculation Methods for Road Freight Transport Activity

2017 ◽  
Vol 18 (2) ◽  
pp. 107-117 ◽  
Author(s):  
György Kovács
Keyword(s):  
State Of The Art ◽  
Common Type ◽  
Estimation Methods ◽  
Cost Calculation ◽  
Transport Activity ◽  
Calculation Methods ◽  
Transport Costs ◽  
Art Practices ◽  
Road Freight ◽  
The Individual

Abstract The transport activity is one of the most expensive processes in the supply chain. Forwarding and transport companies focuses on the optimization of transportation and the reduction of transport costs. The goal of this study is to develop a method which calculate the first (prime) cost of a given transport task more precisely than the state of the art practices. In practice the calculation of transport fee depends on the individual estimation methods of the transport managers, which could result losses for the company. In this study the elaborated calculation method for total first cost is detailed for three types of fulfilment of transport tasks. The most common type of achievement is, when “own vehicle is used with own driver”. A software was also developed for this case based on the elaborated method. Based on the calculations of our software, the first cost can be defined quickly and precisely to realize higher profit.

scholarly journals Effect of Variable Viscosity and Gravity Modulation on Linear and Non-Linear Rayleigh-Benard Convection in Viscoelastic Ferromagnetic Liquids

2020 ◽  
Vol 9 (3) ◽  
pp. 3482-3488
Keyword(s):  
Stability Analysis ◽  
Heat Transport ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Variable Viscosity ◽  
Low Frequency ◽  
Physical Parameters ◽  
Gravity Modulation ◽  
Non Linear ◽  
The Individual

The combined effect of various parameters of gravity modulation on the onset of ferroconvection is studied for both linear and non-linear stability. The effect of various parameters of ferroconvection is studied for linear stability analysis. The resulting seven-mode generalized Lorenz model obtained in non-linear stability analysis is solved using Runge -Kutta-Felberg 45 method to analyze the heat transfer. Consequently the individual effect of gravity modulation on heat transport has been investigated. Further, the effect of physical parameters on heat transport has been analyzed and depicted graphically. The low-frequency gravity modulation is observed to get an effective influence on the stability of the system. Therefore ferro convection can be advanced or delayed by controlling different governing parameters. It shows that the influence of gravity modulation stabilizes system.

scholarly journals Performance Comparison of Various Maximum Likelihood Nonlinear Mixed-Effects Estimation Methods for Dose–Response Models

2012 ◽  
Vol 14 (3) ◽  
pp. 420-432 ◽  
Author(s):  
Elodie L. Plan ◽  
Alan Maloney ◽  
France Mentré ◽  
Mats O. Karlsson ◽  
Julie Bertrand
Keyword(s):  
Maximum Likelihood ◽  
Dose Response ◽  
Mixed Effects ◽  
Performance Comparison ◽  
Estimation Methods ◽  
Nonlinear Mixed Effects ◽  
Response Models

A digital system for generating dynamic sinusoidal gas concentration signals

1988 ◽  
Vol 65 (2) ◽  
pp. 945-949 ◽  
Author(s):  
S. A. Barton ◽  
L. Sutton ◽  
C. E. Hahn ◽  
A. M. Black
Keyword(s):  
Frequency Modulation ◽  
Pulse Frequency ◽  
Respiratory Monitoring ◽  
Gas Mixing ◽  
Pulse Frequency Modulation ◽  
Gas Concentration ◽  
Mixing Chamber ◽  
Computer Controlled ◽  
The Individual ◽  
Valve Switching

A computer-controlled gas-mixing system is presented. It is capable of mixing four gases, the concentration of three of which will follow a path to be determined by the user. For our purposes the output O2 fraction is maintained constant and the levels of Ar and N2O vary sinusoidally and independently, with periods between 0.25 and 30 min. A fourth gas, N2 is necessary to make the sum of the individual fractions 100%. The system uses banks of between one and four solenoid valves each linked via a sonic choke to a common mixing chamber. A regime of pulse frequency modulation is employed. All calculations and timing of valve switching are performed by a dedicated microcomputer built for the purpose. The device has been used to provide respiratory gas forcing functions for a program of research in respiratory monitoring.

scholarly journals Global-Entropy Driven Exploration with Distributed Models under Sparsity Constraints

2018 ◽  
Vol 8 (10) ◽  
pp. 1722 ◽  
Author(s):  
Christoph Manss ◽  
Dmitriy Shutin
Keyword(s):  
Optimization Problem ◽  
Data Distribution ◽  
Consensus Algorithm ◽  
Estimation Methods ◽  
Model Estimation ◽  
Individual Agent ◽  
Distributed Models ◽  
Heterogeneous Learning ◽  
Sparsity Constraints ◽  
The Individual

This paper focuses on exploration when using different data distribution schemes and ADMM as a solver for swarms. By exploration, we mean the estimation of new measurement locations that are beneficial for the model estimation. In particular, the different distribution schemes are splitting-over-features or heterogeneous learning and splitting-over-examples or homogeneous learning. Each agent contributes a solution to solve the joint optimization problem by using ADMM and the consensus algorithm. This paper shows that some information is unknown to the individual agent, and thus, the estimation of new measurement positions is not possible without further communication. Therefore, this paper shows results for how to distribute only necessary information for a global exploration. We show the benefits between the proposed global exploration scheme and benchmark exploration schemes such as random walk and systematic traversing, i.e., meandering. The proposed waypoint estimation methods are then tested against each other and with other movement methods. This paper shows that a movement method, which considers the current information within the model, is superior to the benchmark movement methods.

Commercial microwave links in urban rainfall-runoff modelling: Two different approaches to removing the bias

2020 ◽  
Author(s):  
Jaroslav Pastorek ◽  
Martin Fencl ◽  
Jörg Rieckermann ◽  
Vojtěch Bareš
Keyword(s):  
Wave Attenuation ◽  
Temporal Dynamics ◽  
Estimation Methods ◽  
Rainfall Runoff ◽  
Geophysical Research ◽  
Urban Catchment ◽  
Individual Level ◽  
The Individual ◽  
Commercial Microwave Links ◽  
Heavy Rainfalls

&lt;p&gt;Commercial microwave links (CMLs) are point-to-point radio connections widely used as cellular backhaul and thus very well covering urbanized areas. They can provide path-integrated quantitative precipitation estimates (QPEs) as they operate at frequencies where radio wave attenuation caused by raindrops is almost proportional to rainfall intensity. Pastorek et al. (2019b) demonstrated the feasibility of using CML QPEs to predict rainfall-runoff in a small urban catchment. Unfortunately, runoff volumes were highly biased, mostly for QPEs from short CMLs, although the temporal runoff dynamics were predicted very well, especially during heavy rainfall events. It was also shown that, for the heavy rainfalls, reducing the bias by adjusting the CML QPEs to traditional rainfall measurements (Fencl et al., 2017) leads to less accurate reproduction of the runoff temporal dynamics.&lt;/p&gt;&lt;p&gt;Current understanding is that the bias in CML QPEs is often caused by imprecise estimation of wet antenna attenuation (WAA), which is a complex process influenced by many physical phenomena, including radome hardware or positioning of the outdoor unit. However, traditional WAA estimation methods are typically unable to take into account all the individual-level factors. We proposed (Pastorek et al., 2019a) to estimate WAA separately for each of the examined CMLs by using discharge measurements at the outlet of a small urban catchment and showed that this approach can reduce the bias in CML QPEs, leading to generally satisfying performance of rainfall-runoff models, mainly for heavy rainfalls.&lt;/p&gt;&lt;p&gt;In the presented study, we evaluate the effect of the method proposed in Pastorek et al. (2019a) (method i) on rainfall-runoff modelling in more detail and compare it to the method of Fencl et al. (2017) (method ii). For a case study in Prague-Let&amp;#328;any, Czech Rep., a calibrated rainfall-runoff model is used to predict discharges at the outlet of the small urban catchment (1.3 km&lt;sup&gt;2&lt;/sup&gt;) using QPEs from 16 CMLs. First results confirm that minimizing the bias in CML QPEs using method i is convenient mainly for heavy rainfalls, as Nash-Sutcliffe efficiency is considerably higher in this case for all but one CML (on average 0.65; only 0.40 for method ii). Moreover, method i preserves the information about the rainfall temporal dynamics during heavy rainfalls better than method ii for most of the individual CMLs (correlation coefficient with observed runoffs on average 0.83 for method i and 0.78 for method ii). Next steps should include generalization for other case studies, including an exploratory analysis of the potential mismatches.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Fencl, M., Dohnal, M., Rieckermann, J., Bare&amp;#353;, V., 2017. Gauge-adjusted rainfall estimates from commercial microwave links. Hydrol. Earth Syst. Sci. 21, 617&amp;#8211;634.&lt;/p&gt;&lt;p&gt;Pastorek, J., Fencl, M., Rieckermann, J. and Bare&amp;#353;, V., 2019b. Commercial microwave links for urban drainage modelling: The effect of link characteristics and their position on runoff simulations. Journal of environmental management 251, 109522.&lt;/p&gt;&lt;p&gt;Pastorek, J., Fencl, M., and Bare&amp;#353;, V., 2019a. Calibrating microwave link rainfall retrieval model using runoff observations. Geophysical Research Abstracts 21, EGU2019-10072.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;This study was supported by the project no. 20-14151J of the Czech Science Foundation and by the project of the Czech Technical University in Prague no. SGS19/045/OHK1/1T/11.&lt;/p&gt;

scholarly journals RESULTS OF PETROPHYSICAL STUDIES OF THE PRODUCTIVE STRATUM DEPOSITS OF THE BAKU ARCHIPELAGO NORTHERN OIL AND GAS BEARING AREAS

2020 ◽  
pp. 22-27
Author(s):  
V. Sultanov ◽  
L. Sultanov
Keyword(s):  
Granulometric Composition ◽  
Oil And Gas ◽  
Physical Parameters ◽  
Reservoir Properties ◽  
Secondary Porosity ◽  
North West ◽  
Productive Stratum ◽  
Porosity And Permeability ◽  
The Individual ◽  
Lithological Composition

The complex results of petrophysical testing of rocks, taken from prospecting-development wells of Duvanni-deniz, Sangachal-deniz, Bulla-deniz, Garasu and etc. areas, where the sediments of productive stratum are widely expanded, have been given. Average values of granulometric composition of rocks of productive unit of the above areas by the section have been recounted. The problem of dependence of permeability on porosity and depth was solved. Dependence between physical parameters for the individual kinds of rocks, dependence between physical properties and material structures are established. The results of various petrophysical research methods show that the filtration capacitance properties, in general, deteriorate with depth. However, in certain cases, in clay and carbonate rocks, reservoir properties can improve, due to the appearance of secondary porosity under relatively stringent thermobaric conditions. The histograms, which consist of average values of granulometric composition of productive stratum rocks when crossing some places of archipelago are constructed, the problems of dependence of permeability on porosity and depth were solved. The researches showed, that the physical process of the same- named and same-aged features rocks change in the result of geological-physical processes, getting different values. It's noticed, that the porosity and permeability are increasing from north-west to south-east by changing lithological composition.

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