EXPERIMENTAL STUDY OF THE INFLUENCE OF THE MODE OF FINAL TREATMENT ON THE QUALITY OF THE FLAT SURFACES OF ALUMINIUM MATERIALS

2020 ◽  
pp. 30-35
Author(s):  
M. G. Galkin ◽  
A. S. Smagin ◽  
A. S. Poupyreva
Keyword(s):  
Mathematical Model ◽  
A Priori ◽  
Research Area ◽  
Machining Process ◽  
Second Phase ◽  
Forming Process ◽  
Flat Surfaces ◽  
Final Treatment ◽  
Priori Information

In the process of multivariate design of machining technology, one of the important tasks is to select the optimal cutting conditions at the final transitions of the forming process, providing a given quality of the surfaces on the workpiece made of the appropriate material. At the same time, to describe most of the design procedures of the machining process, there are problems associated with the algorithm for choosing the solution method, the response function and the range of acceptable solutions at all stages of processing. In this paper, as an algorithm for solving the problem, we propose the use of the known method of extreme planning of the experiment, which allows to obtain a mathematical model of the investigated multifactorial process with incomplete knowledge of its optimization mechanism. In the process of implementation of this algorithm in real production conditions on the basis of a priori information, the research area was chosen and the main levels of factors and intervals of their variation in this area were established. Then a full factorial experiment was carried out and its results were processed on the basis of a linear polynomial taking into account linear effects and interaction effects. As a result of testing the polynomial confidence intervals were determined for all regression coefficients by four parallel experiments at the same values of factors. In the second phase, were evaluated the adequacy of most mathematical models of the Fisher test. In the end, the transition from the coded values of the factors in the mathematical model to their natural values was carried out. Using the final model with natural values of the factors, a numerical experiment was conducted, which determined the optimum region with the most unfavorable treatment mode. Such a study allows to simplify the procedure for assigning the processing mode of the workpiece at the final stage in the conditions of the current production, while ensuring the specified quality of the machined surfaces and maintaining the productivity of the forming process. This technique is the subject of consideration in this work.

scholarly journals A method for improved SCIAMACHY CO2 retrieval in the presence of optically thin clouds

2010 ◽  
Vol 3 (1) ◽  
pp. 209-232 ◽  
Author(s):  
M. Reuter ◽  
M. Buchwitz ◽  
O. Schneising ◽  
J. Heymann ◽  
H. Bovensmann ◽  
...  
Keyword(s):  
Absorption Band ◽  
Near Infrared ◽  
A Priori ◽  
Optimal Estimation ◽  
Surface Flux ◽  
Co2 Absorption ◽  
Retrieval Scheme ◽  
Priori Information ◽  
Transfer Of Information

Abstract. An optimal estimation based retrieval scheme for satellite based retrievals of XCO2 (the dry air column averaged mixing ratio of atmospheric CO2) is presented enabling accurate retrievals also in the presence of thin clouds. The proposed method is designed to analyze near-infrared nadir measurements of the SCIAMACHY instrument in the CO2 absorption band at 1580 nm and in the O2-A absorption band at around 760 nm. The algorithm accounts for scattering in an optically thin cirrus cloud layer and at aerosols of a default profile. The scattering information is mainly obtained from the O2-A band and a merged fit windows approach enables the transfer of information between the O2-A and the CO2 band. Via the optimal estimation technique, the algorithm is able to account for a priori information to further constrain the inversion. Test scenarios of simulated SCIAMACHY sun-normalized radiance measurements are analyzed in order to specify the quality of the proposed method. In contrast to existing algorithms for SCIAMACHY retrievals, the systematic errors due to cirrus clouds with optical thicknesses up to 1.0 are reduced to values below 4 ppm for most of the analyzed scenarios. This shows that the proposed method has the potential to reduce uncertainties of SCIAMACHY retrieved XCO2 making this data product potentially useful for surface flux inverse modeling.

Study of the Effect of Hot Gas on Atomization Quality of Spray Forming

2013 ◽  
Vol 774-776 ◽  
pp. 1190-1193
Author(s):  
Qing Yang ◽  
Ying Dong Qu ◽  
Rui Ming Su ◽  
Bing Kun Zheng ◽  
Yu Sheng Wu
Keyword(s):  
Mathematical Model ◽  
Grain Size ◽  
Grain Shape ◽  
Spray Forming ◽  
Forming Process ◽  
Hot Gas ◽  
Average Grain Size ◽  
Calculation Results ◽  
First Time

In the spray forming process, the atomizing quality is not very good under the low pressure. This article attempts to improve the quality of atomization through heating the gas. A mathematical model is built and calculated according to the existing knowledge, and then the influence of airflow temperature in the spray forming is theoretical calculated and analyzed. The experimental results show that the average grain size is 54μm when the gas is not heated; the average grain size is 39 μm which decreases by 27.7% than airflow unheated when the gas is heated to 150 °C. The calculation results show that when the gas is not heated, the first time atomization grain size is 201 μm, the second time atomization grain size is 15 μm, the total atomization time is 92 μs. And the velocity of atomization droplets is 80 m/s; when the airflow temperature is 150°C, the above results are 131 μm, 10 μm, 76 μs and 127 m/s respectively, the atomization quality has a certain improvement compared to the unheated condition. At the same time, the grain shape becomes more round as the temperature of airflow increases, and the holes between the grains also become smaller.

scholarly journals Images denoising in case impulse noise using spline approximation

2018 ◽  
Vol 226 ◽  
pp. 04045 ◽  
Author(s):  
Dmitriy A. Bezuglov ◽  
Viacheslav V. Voronin ◽  
Vladimir A. Krutov
Keyword(s):  
Impulse Noise ◽  
High Efficiency ◽  
Autonomous Robots ◽  
A Priori ◽  
Spline Approximation ◽  
Experimental Studies ◽  
Image Filtering ◽  
Spline Functions ◽  
Priori Information

Analytical equations of a new spline approximation method for filtering impulse noise in images are obtained. The proposed method differs from the known ones: when filtering images, one-dimensional sequential spline functions are used for direct and inverse transformations, and the processing is performed in rows and columns. In this work, experimental studies based on computer simulation using special test images on the background of impulse noise were conducted. Experimental studies have shown the operability and high efficiency of the developed method, which allow to improve the quality of image filtering by up to 10 dB. In this case, the properties of spline functions make it possible to abandon the use of various masks, that is, to abandon inefficient linear methods of image filtering. The method can be used to create digital image processing systems in the industry, to create autonomous robots, under observation conditions that complicate the registration process, and in the absence of a priori information about the form of background noise.

scholarly journals Bayesian Perspective in the Selection of Bean Genotypes

2020 ◽  
Vol 12 (9) ◽  
pp. 173
Author(s):  
Tâmara Rebecca A. de Oliveira ◽  
Moysés Nascimento ◽  
Paulo R. Santos ◽  
Kleyton Danilo S. Costa ◽  
Thalyson V. Lima ◽  
...  
Keyword(s):  
Bayesian Method ◽  
Block Design ◽  
A Priori ◽  
A Priori Information ◽  
Bayesian Procedure ◽  
R Software ◽  
Randomized Block Design ◽  
Priori Information ◽  
Selection Of

Changes in the relative performance of genotypes have made it necessary for more in-depth investigations to be carried out through reliable analyses of adaptability and stability. The present study was conducted to compare the efficiency of different informative priors in the Bayesian method of Eberhart & Russel with frequentist methods. Fifteen black-bean genotypes from the municipalities of Belém do São Francisco and Petrolina (PE, Brazil) were evaluated in 2011 and 2012 in a randomized-block design with three replicates. Eberhart & Russel’s methodology was applied using the GENES software and the Bayesian procedure using the R software through the MCMCregress function of the MCMCpack package. The quality of Bayesian analysis differed according to the a priori information entered in the model. The Bayesian approach using frequentist analysis had greater accuracy in the estimate of adaptability and stability, where model 1 which uses the a priori information, was the most suitable to obtain reliable estimates according to the BayesFactor function. The inference, using information from previous studies, showed to be imprecise and equivalent to the linear-model methodology. In addition, it was realized that the input of a priori information is important because it increases the quality of the adjustment of the model.

Synergetic approach to improve the efficiency of machining process control on metal-cutting machines

2021 ◽  
Vol 23 (3) ◽  
pp. 84-99
Author(s):  
Vilor Zakovorotny ◽  
◽  
Valery Gvindjiliya ◽  
Keyword(s):  
Dynamic System ◽  
Internal Control ◽  
Metal Cutting ◽  
A Priori ◽  
Machining Process ◽  
External Control ◽  
Processing Efficiency ◽  
Cutting System ◽  
Required Quality

Introduction. The efficiency of processing on metal-cutting machines is evaluated by the reduced cost of producing a batch of parts while ensuring the required quality. In modern production, parts are usually made on CNC machines. Today the CNC program and the trajectories of the machine tool actuators match each other with high accuracy, which, however, does not yet guarantee quality and efficiency of production. The definition of the CNC program is based on the knowledge base of rational modes, tools, coolant and etc. during processing. This base reflects some averaging over the set of machines, tools and processing conditions, and does not take into account changes in the properties of the dynamic system in the process of cutting. Subject. The paper deals with the synergistic matching of external control (CNC programs) and cutting dynamics (internal control). The internal control factors can be set a priori, as well as determined as a result of the influence of irreversible energy transformations in the cutting zone. The purpose of the work is to determine the law of controlling the trajectories of the machine's executive elements in such a way that, with changing properties of the dynamic cutting system, the required surface quality of the part and minimizing the intensity of tool wear are ensured during the processing of the part. Method and methodology. Mathematical simulation of the controlled dynamic system, which properties change due to the a priori set laws of variation of subsystem parameters, as well as changes in the cutting properties conditioned by the power of irreversible energy transformation is presented. Consideration of the power of irreversible energy transformations is necessary for predicting back-edge wear, changes in dynamic coupling parameters, and evolutionary restructuring of cutting dynamics. Results and Discussion. The regularity of matching the CNC program with the changing properties of the cutting process, which allows increasing the processing efficiency while ensuring the required quality of parts, is disclosed. A number of properties of the dynamic cutting system caused by changing trajectory of the longitudinal feed rate of the tool during processing of the shaft, the stiffness change of which is given, are revealed and analyzed.

MODELING UNDER LOCAL STRUCTURE HYPOTHESES

1993 ◽  
Vol 03 (04) ◽  
pp. 445-451
Author(s):  
SERGE V. PLOTNIKOV
Keyword(s):  
Mathematical Model ◽  
Pattern Recognition ◽  
Local Structure ◽  
Characteristic Property ◽  
A Priori ◽  
A Priori Information ◽  
Typical Problem ◽  
Suggested Approach ◽  
Priori Information

A mathematical model of a typical problem of pattern recognition is described. Its characteristic property is that it pays special attention to a priori information concerning the local structure of the object under investigation. Algorithmic backgrounds (using convex analytic tools) of the suggested approach are presented.

scholarly journals Generation of a Bending Angle Radio Occultation Climatology (BAROCLIM) and its use in radio occultation retrievals

2014 ◽  
Vol 7 (8) ◽  
pp. 8193-8231 ◽  
Author(s):  
B. Scherllin-Pirscher ◽  
S. Syndergaard ◽  
U. Foelsche ◽  
K. B. Lauritsen
Keyword(s):  
Radio Occultation ◽  
Weather Prediction ◽  
A Priori ◽  
A Priori Information ◽  
Bending Angle ◽  
Weather Forecasts ◽  
Global Statistics ◽  
Priori Information ◽  
Bending Angles

Abstract. In this paper, we introduce a bending angle radio occultation climatology (BAROCLIM) based on Formosat-3/COSMIC (F3C) data. This climatology represents the monthly-mean atmospheric state from 2006 to 2012. Bending angles from radio occultation (RO) measurements are obtained from the accumulation of the change in the raypath direction of Global Positioning System (GPS) signals. Best quality of these near-vertical profiles is found from the middle troposphere up to the mesosphere. Beside RO bending angles we also use data from the Mass Spectrometer and Incoherent Scatter Radar (MSIS) model to expand BAROCLIM in a spectral model, which (theoretically) reaches from the surface up to infinity. Due to the very high quality of BAROCLIM up to the mesosphere, it can be used to detect deficiencies in current state-of-the-art analysis and reanalysis products from numerical weather prediction (NWP) centers. For bending angles derived from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis fields from 2006 to 2012, e.g., we find a positive bias of 0.5% to % at 40 km, which increases to more than 2% at 50 km. BAROCLIM can also be used as a priori information in RO profile retrievals. In contrast to other a priori information (i.e., MSIS) we find that the use of BAROCLIM better preserves the mean of raw RO measurements. Global statistics of statistically optimized bending angle and refractivity profiles also confirm that BAROCLIM outperforms MSIS. These results clearly demonstrate the utility of BAROCLIM.

scholarly journals A method for improved SCIAMACHY CO<sub>2</sub> retrieval in the presence of optically thin clouds

2009 ◽  
Vol 2 (5) ◽  
pp. 2483-2538 ◽  
Author(s):  
M. Reuter ◽  
M. Buchwitz ◽  
O. Schneising ◽  
J. Heymann ◽  
H. Bovensmann ◽  
...  
Keyword(s):  
Absorption Band ◽  
Near Infrared ◽  
A Priori ◽  
Optimal Estimation ◽  
Surface Flux ◽  
Co2 Absorption ◽  
Retrieval Scheme ◽  
Priori Information ◽  
Transfer Of Information

Abstract. An optimal estimation based retrieval scheme for satellite based measurements of XCO2 (the column averaged mixing ratio of atmospheric CO2) is presented enabling accurate retrievals also in the presence of thin clouds. The proposed method is designed to analyze near-infrared nadir measurements of the SCIAMACHY instrument in the CO2 absorption band at 1580 nm and in the O2-A absorption band at around 760 nm. The algorithm accounts for scattering in an optically thin cirrus cloud layer and at aerosols of a default profile. The scattering information is mainly obtained from the O2-A band and a merged fit windows approach enables the transfer of information between the O2-A and the CO2 band. Via the optimal estimation technique, the algorithm is able to account for a priori information to further constrain the inversion. Test scenarios of simulated SCIAMACHY sun-normalized radiance measurements are analyzed in order to specify the quality of the proposed method. In contrast to existing algorithms, the systematic errors due to cirrus clouds with optical thicknesses up to 1.0 are reduced to values typically below 4 ppm. This shows that the proposed method has the potential to reduce uncertainties of SCIAMACHY retrieved XCO2 making this data product useful for surface flux inverse modeling.

scholarly journals Intercomparison of arctic XH<sub>2</sub>O observations from three ground-based Fourier transform infrared networks and application for satellite validation

2021 ◽  
Vol 14 (3) ◽  
pp. 1993-2011
Author(s):  
Qiansi Tu ◽  
Frank Hase ◽  
Thomas Blumenstock ◽  
Matthias Schneider ◽  
Andreas Schneider ◽  
...  
Keyword(s):  
Fourier Transform ◽  
A Priori ◽  
Fourier Transform Infrared ◽  
Total Carbon ◽  
Atmospheric Composition ◽  
Satellite Validation ◽  
Ftir Spectrometer ◽  
Priori Information ◽  
Good Agreement

Abstract. In this paper, we compare column-averaged dry-air mole fractions of water vapor (XH2O) retrievals from the COllaborative Carbon Column Observing Network (COCCON) with retrievals from two co-located high-resolution Fourier transform infrared (FTIR) spectrometers as references at two boreal sites, Kiruna, Sweden, and Sodankylä, Finland, from 6 March 2017 to 20 September 2019. In the framework of the Network for the Detection of Atmospheric Composition Change (NDACC), an FTIR spectrometer is operated at Kiruna. The H2O product derived from these observations has been generated with the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) processor. In Sodankylä, a Total Carbon Column Observing Network (TCCON) spectrometer is operated, and the official XH2O data as provided by TCCON are used for this study. The datasets are in good overall agreement, with COCCON data showing a wet bias of (49.20±58.61) ppm ((3.33±3.37) %, R2=0.9992) compared with MUSICA NDACC and (56.32±45.63) ppm ((3.44±1.77) %, R2=0.9997) compared with TCCON. Furthermore, the a priori H2O volume mixing ratio (VMR) profiles (MAP) used as a priori information in the TCCON retrievals (also adopted for COCCON retrievals) are evaluated with respect to radiosonde (Vaisala RS41) profiles at Sodankylä. The MAP and radiosonde profiles show similar shapes and a good linear correlation of integrated XH2O, indicating that MAP is a reasonable approximation of the true atmospheric state and an appropriate choice for the scaling retrieval methods as applied by COCCON and TCCON. COCCON shows a reduced dry bias (−14.96 %) in comparison with TCCON (−19.08 %) with respect to radiosonde XH2O. Finally, we investigate the quality of satellite data at high latitudes. For this purpose, the COCCON XH2O is compared with retrievals from the Infrared Atmospheric Sounding Interferometer (IASI) generated with the MUSICA processor (MUSICA IASI) and with retrievals from the TROPOspheric Monitoring Instrument (TROPOMI). Both paired datasets generally show good agreement and similar correlations at the two sites. COCCON measures 4.64 % less XH2O at Kiruna and 3.36 % less at Sodankylä with respect to MUSICA IASI, whereas COCCON measures 9.71 % more XH2O at Kiruna and 7.75 % more at Sodankylä compared with TROPOMI. Our study supports the assumption that COCCON also delivers a well-characterized XH2O data product. This emphasizes that this approach might complement the TCCON network with respect to satellite validation efforts. This is the first published study where COCCON XH2O has been compared with MUSICA NDACC and TCCON retrievals and has been used for MUSICA IASI and TROPOMI validation.

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