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Wyszukujesz frazę "quality analysis" wg kryterium: Temat


Tytuł:
Data mining model for quality control of primary aluminum production process
Autorzy:
Horvath, M.
Vircikova, E.
Powiązania:
https://bibliotekanauki.pl/articles/406754.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
quality control analysis
data mining
multivariate autocorrelated process
quality improvement
Opis:
Traditional statistical process control approaches are less effective in dealing with multivariate and autocorrelated processes. With the continual increase in process complexity, this inefficiency is becoming more apparent. A special type of multivariate and autocorrelated process is a process occurring within a heterogeneous production environment (a variety of types of machines, pots, etc. used for the same task). This makes the quality control of such processes more difficult. The approach presented in the paper utilizes time series fitting, cluster analysis and association mining in relation to a single data mining model for the analysis of complex multivariate autocorrelated processes. The aim is to divide the production cells (machines, pots, etc.) into groups exhibiting similar behaviors. This can then be used for more effective quality control of the entire process and afterwards to analyze the reasons for this behavior. This paper includes someof the results obtained from applying the model to an actual multivariate high autocorrelated process, the production of primary aluminum using the Hall-Heroult electrolysis process. The Hall-Heroult electrolysis process is a continual process that is ongoing in several pots simultaneously. The average plant operates 300 pots. Therefore, the quality control of such a complex process faces many issues concerning monitoring and problem diagnosis. The paper describes a method for dividing the pots into control groups exhibiting similar behaviors, which can then be used in the planning phase of the quality control analysis and to make improvements within these groups and thereby within the whole process.
Źródło:
Management and Production Engineering Review; 2012, 3, 4; 47-53
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Data mining system for air quality monitoring networks
Autorzy:
Czechowski, P.
Badyda, A.
Majewski, G.
Powiązania:
https://bibliotekanauki.pl/articles/204820.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
air pollutants
data quality analysis
data mining
estimation
exploratory methods
harmonic
principal component analysis
statistical tests outliers
influential
leverage observations
analytical software system
programming
Eco Data Miner
EDM
Winsorized mean
Cook
Mahalanobis distance
DFITS
COVRATIO
Opis:
The use of quantitative methods, including stochastic and exploratory techniques in environmental studies does not seem to be sufficient in practical aspects. There is no comprehensive analytical system dedicated to this issue, as well as research regarding this subject. The aim of this study is to present the Eco Data Miner system, its idea, construction and implementation possibility to the existing environmental information systems. The methodological emphasis was placed on the one-dimensional data quality assessment issue in terms of using the proposed QAAH1 method - using harmonic model and robust estimators beside the classical tests of outlier values with their iterative expansions. The results received demonstrate both the complementarity of proposed classical methods solution as well as the fact that they allow for extending the range of applications significantly. The practical usefulness is also highly significant due to the high effectiveness and numerical efficiency as well as simplicity of using this new tool.
Źródło:
Archives of Environmental Protection; 2013, 39, 4; 123-147
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of the heated water discharge on the water quality in a shallow lowland dam reservoir
Autorzy:
Mazierski, Jerzy
Kostecki, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/1845417.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
water quality
factor analysis
multivariate statistical analysis
Opis:
The purpose of the work was to determine the relationship between the of the water quality parameters in an artificial reservoir used as cooling ponds. Factor analysis were applied to analyze eighteen physico- -chemical parameters such as air and water temperature, dissolved oxygen concentration, visibility of the Secchi disk, concentrations of total nitrogen, ammonium, nitrate, nitrite, total phosphorus, phosphate, concentrations of calcium, magnesium, chlorides, sulfates and total dissolved salts, pH, chemical oxygen demand and electric conductivity from 2002-2019 to investigated cooling water discharge. Exploratory factor analysis allowed identified four factors were obtained from 54.1% (in discharge zone) to 56.7% (in dam zone). In discharge and pelagic zones confirmatory factor analysis showed that four latent variables: salinity, temperature, nitrogen and phosphorus provide good fit, but in the dam zone the better fit was obtained for the latent variables salinity, temperature, nutrient and eutrophic. Correlations between latent variables temperature, nitrogen, phosphorus or nutrient and eutrophic show a significant effect of temperature on the transformation of nitrogen and phosphorus compounds.
Źródło:
Archives of Environmental Protection; 2021, 47, 2; 29-46
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of environmetric methods to investigate control factors on water quality
Autorzy:
Boyacioglu, H.
Powiązania:
https://bibliotekanauki.pl/articles/205171.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
water quality
factor analysis
environmetric methods
discriminant analysis
Opis:
In the study, environmetric methods were successfully performed a) to explore natural and anthropogenic controls on reservoir water quality, b) to investigate spatial and temporal differences in quality, and c) to determine quality variables discriminating three reservoirs in Izmir, Turkey. Results showed that overall water quality was mainly governed by “natural factors” in the whole region. A parameter that was the most important in contributing to water quality variation for one reservoir was not important for another. Between summer and winter periods, difference in arsenic concentrations were statistically significant in the Tahtalı, Ürkmez and iron concentrations were in the Balçova reservoirs. Observation of high/low levels in two seasons was explained by different processes as for instance, dilution from runoff at times of high flow seeped through soil and entered the river along with the rainwater run-off and adsorption. Three variables “boron, arsenic and sulphate” discriminated quality among Balçova & Tahtalı, Balçova & Ürkmez and two variables “zinc and arsenic” among the Tahtalı & Ürkmez reservoirs. The results illustrated the usefulness of multivariate statistical techniques to fingerprint pollution sources and investigate temporal/spatial variations in water quality.
Źródło:
Archives of Environmental Protection; 2017, 43, 3; 17-23
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prony’s method with reduced sampling - numerical aspects
Autorzy:
Zygarlicki, J.
Mroczka, J.
Powiązania:
https://bibliotekanauki.pl/articles/220676.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal analysis
harmonic analysis
signal processing
power quality
Opis:
This paper presents a new modification of the least-squares Prony’s method with reduced sampling, which allows for a significant reduction in the number of the analysed signal samples collected per unit time. The specific combination of non-uniform sampling with Prony’s method enables sampling of the analysed signals at virtually any average frequency, regardless of the Nyquist frequency, maintaining high accuracy in parameter estimation of sinusoidal signal components. This property allows using the method in measuring devices, such as for electric power quality testing equipped with low power signal processors, which in turn contributes to reducing complexity of these devices. This paper presents research on a method for selecting a sampling frequency and an analysis window length for the presented method, which provide maximum estimation accuracy for Prony’s model component parameters. This paper presents simulation tests performed in terms of the proposed method application for analysis of harmonics and interharmonics in electric power signals. Furthermore, the paper provides sensitivity analysis of the method, in terms of common interferences occurring in the actual measurement systems.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 521-534
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the use of multi-harmonic least-squares fitting for THD estimation in power quality analysis
Autorzy:
Ramos, P. M.
Janeiro, F. M.
Radil, T.
Powiązania:
https://bibliotekanauki.pl/articles/220641.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
harmonic analysis
power quality
signal reconstruction
spectral analysis
harmonic distortion
Opis:
The quality of the supplied power by electricity utilities is regulated and of concern to the end user. Power quality disturbances include interruptions, sags, swells, transients and harmonic distortion. The instruments used to measure these disturbances have to satisfy minimum requirements set by international standards. In this paper, an analysis of multi-harmonic least-squares fitting algorithms applied to total harmonic distortion (THD) estimation is presented. The results from the different least-squares algorithms are compared with the results from the discrete Fourier transform (DFT) algorithm. The algorithms are assessed in the different testing states required by the standards.
Źródło:
Metrology and Measurement Systems; 2012, 19, 2; 295-306
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Canine post-thaw sperm quality can be predicted by using CASA, and classification and regression tree (CART)-analysis
Autorzy:
Schäfer-Somi, S.
Tichy, A.
Powiązania:
https://bibliotekanauki.pl/articles/2087565.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dogs
spermatozoa
crypreservation
quality prediction
CART-analysis
Źródło:
Polish Journal of Veterinary Sciences; 2019, 1; 51-59
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of environmetric & index methods as water quality comparative assessment tools focusing on heavy metal content
Autorzy:
Boyacioglu, H.
Powiązania:
https://bibliotekanauki.pl/articles/204558.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cluster analysis
factor analysis
heavy metal
pollution fingerprint
water quality index
Opis:
In the study suitability of water quality index approach and environmetric methods in fi ngerprinting heavy metal pollution as well as comparison of spatial variability of multiple contaminants in surface water were assessed in the case of The Gediz River Basin, Turkey. Water quality variables were categorized into two classes using factor and cluster analysis. Furthermore, soil contamination index was adapted to water pollution index and used to fi nd out the relative relationship between the reference standards and the current situation of heavy metal contamination in water. Results revealed that surface water heavy metal content was mainly governed by metal processing, textile and tannery industries in the region. On the other hand, metal processing industry discharges mainly degraded quality of water in Kemalpasa and Menemen. Furthermore, Kemalpasa region has been heavily affected from tannery and textile industries effl uents. Moreover, pollution parameters have not been infl uenced by changes in physical factors (discharge and temperature). This study indicated the effectiveness of water quality index approach and statistical tools in fi ngerprinting of pollution and comparative assessment of water quality. Both methods can assist decision makers to determine priorities in management practices.
Źródło:
Archives of Environmental Protection; 2012, 38, 3; 17-28
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation into a Potential Reduction of FMEA Efforts Using Action Priority
Autorzy:
Barsalou, Matthew
Powiązania:
https://bibliotekanauki.pl/articles/2201159.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FMEA
failure modes and effects analysis
risk analysis
failure prevention
quality
Opis:
FMEAs have been prioritized using RPN; however, a new standard has introduced AP for prioritization. This study seeks to determine if the number of required improvement actions increases, decreases, or stays the same when using AP in place of RPN. Statistical software was used to simulate 10,000 combinations of severity, occurrence, and detection. Both AP and RPN were calculated for the 10,000 combinations. Statistical hypothesis testing was performed to determine if there was a difference between RPNs when sorted by AP and to determine if there was a difference in actions required using RPN or AP. There is a statistically significant difference between RPNs when sorted by high, medium, and low AP. Using an RPN threshold equal to or greater than 100 would result in no change in the number of actions required if prioritizing by high and medium, but would result in fewer actions required if only high is used.
Źródło:
Management and Production Engineering Review; 2022, 13, 4; 59--71
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an innovative approach for complex, causally determined failure chains
Autorzy:
Bielefeld, O.
Dransfeld, H.
Schlüter, N.
Winzer, P.
Powiązania:
https://bibliotekanauki.pl/articles/407289.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
model-based failure analysis
reliability
quality
safety
Opis:
A high number of examples in today’s global industry prove that it is difficult to ensure a certain level of quality. One possible reason is the increasing complexity of modern mechatronic product systems. Interface problems due to several involved science disciplines and the lack of understanding subsystems, which are delivered by different suppliers, make it difficult to identify critical components and specifications of elements. Furthermore, it is even harder to estimate the effects of elements because of their unknown dependencies and relations. Therefore it becomes more and more improbable to develop a safe, sustainable and high quality product right from the beginning. In order to understand failures in complex system structures today’s engineering industries need a generic approach that increases the understanding of systems, identifies critical components and considers the different levels of a system. It shall examine failures that cause system errors but also failures that limit system functions. Thus, it is necessary to model and simulate the causally failure chains and analyse over several system levels and elements with their dependencies. This leads to a better understanding of the whole picture of cause and effect. This research paper points out which requirements this new model-based approach has to fulfill and how it is possible to link quality and reliability methods to achieve an overall understanding and analysis of a complex system to assure high quality and sustainability.
Źródło:
Management and Production Engineering Review; 2017, 8, 3; 3-12
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Reliability of Measurement Data and Adequacy of the Measurement Systems in Improving Quality of Casting Products
Autorzy:
Fedoryszyn, A.
Brzeziński, M.
Powiązania:
https://bibliotekanauki.pl/articles/380770.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
quality control
cast quality
measurement system analysis
repeatability analysis
reproducibility analysis
kontrola jakości
jakość odlewu
analiza systemu pomiarowego
analiza powtarzalności
analiza odtwarzalności
Opis:
The study summarises the analysis of reliability assessment of measurements of a selected critical property of a high-precision casting product. Measurement data must be sufficiently reliable to be used in decision-making relating to quality control and the selection of the casting manufacturing technology. The applied procedure is illustrated by study of the variability range of readouts depending on the measurement conditions, obtained by the computer methods. The applied R&R (Repeatability and Reproducibility) procedure is major component of the widely employed Measurement System Analysis (MSA).
Źródło:
Archives of Foundry Engineering; 2015, 15, 3 spec.; 124-126
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Effective Coverage Calculation Methods for Image Quality Assessment Databases
Autorzy:
Buczkowski, M.
Stasiński, R.
Powiązania:
https://bibliotekanauki.pl/articles/225967.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Image Quality Assessment
IQA database analysis
effective coverage
Opis:
This article provides a comparison of a three methods that can be used for calculating effective coverage of image quality assessment database. The aim of this metric is to show how well the database is filled with variety of images. For each image in the database the Spatial Information (SI) and Colorfulness (CF) metric is calculated. The area of convex hull containing all the points on SI x CF plane is indication of total coverage of the database, but it does not show how efficiently this area is utilized. For this purpose an effective coverage was introduced. An analysis is performed for 16 databases - 13 publicaly available and 3 artificial created for the purpose of showing advantages of the effective coverage.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 3; 307-313
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modal Parameters of Two Violins with Different Varnish Layers and Subjective Evaluation of Their Sound Quality
Autorzy:
Skrodzka, E. B.
Linde, B.B.J.
Krupa, A.
Powiązania:
https://bibliotekanauki.pl/articles/176852.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
violin
modal analysis
varnish
subjective sound quality evaluation
Opis:
Two violins were investigated. The only intentionally introduced difference between them was the type of varnish. One of the instruments was covered with a spirit varnish, the other was oil varnished. Experimental modal analysis was done for unvarnished/varnished violins and a questionnaire inquiry on the instrument’s sound quality was performed. The aim of both examinations was to find differences and similarities between the two instruments in the objective (modal parameters) and subjective domain (subjective evaluation of sound quality). In the modal analysis, three strongly radiating signature modes were taken into account. Varnishing did not change the sequence of mode shapes. Modal frequencies A0 and B(1+) were not changed by oil varnishing compared to the unvarnished condition. For the oil varnished instrument, the frequency of mode B(1+) was lower than that of the same mode of the spirit varnished instrument. Our two violins were not excellent instruments, but before varnishing they were practically identical. However, after varnishing it appeared that the oil-varnished violin was better than the spirit-varnished instrument. Therefore, it can be assumed with a fairly high probability that also in general, the oil-varnished violins sound somewhat better than initially identical spirit-varnished ones.
Źródło:
Archives of Acoustics; 2013, 38, 1; 75-81
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Product quality assessment – measurement and analysis of surface topography
Autorzy:
Niemczewska-Wójcik, M.
Sładek, J.
Tabaka, M.
Wójcik, A.
Powiązania:
https://bibliotekanauki.pl/articles/220537.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
surface metrology
topography
measurement devices
analysis of defects
quality
Opis:
This paper concerns the issues of measurement techniques, analysis and assessment of the machined surface geometric structure. The aim of this work was to show the application of surface analysis in diagnosing the causes of discrepancies occurring in the manufacturing process, which may result from ill-matched (poorly fitting) process parameters. An appropriate system of control and interpretation of results may allow early reaction to unfavorable trends (for example blunting of the tool) and prevention of undesirable defects. The subject of research was a waste basket used in the construction of retaining sewer systems. In this paper, the quality of the waste basket as well as its manufacturing process were analyzed and assessed. The research was carried out with the use of three measurement stands, i.e. optical microscopy (OM), scanning electron microscopy (SEM) and white light interferometer (WLI). The surface analysis proved to be important from the viewpoint of outlining the production process as well as improving the product quality. The software used for topographical analysis appeared to be significant for the success of the analysis, providing notable economic effects, namely the lack of defects.
Źródło:
Metrology and Measurement Systems; 2014, 21, 2; 271-280
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of QoS Methods in the Information Networks with Fractal Traffic
Autorzy:
Daradkeh, Y. I.
Kirichenko, L.
Radivilova, T.
Powiązania:
https://bibliotekanauki.pl/articles/227166.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
communication system traffic
fractals
quality of service
queueing analysis
routing
Opis:
The paper discusses actual task of ensuring the quality of services in information networks with fractal traffic. The generalized approach to traffic management and quality of service based on the account of multifractal properties of the network traffic is proposed. To describe the multifractal traffic properties, it is proposed to use the Hurst exponent, the range of generalized Hurst exponent and coefficient of variation. Methods of preventing of network overload in communication node, routing cost calculation and load balancing, which based on fractal properties of traffic are presented. The results of simulation have shown that the joint use of the proposed methods can significantly improve the quality of service network.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 1; 27-32
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł

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