Wyniki wyszukiwania - BazTech

1

Improving Crop Yield Predictions in Morocco Using Machine Learning Algorithms

Ed-Daoudi Rachid, Alaoui Altaf, Ettaki Badia, Zerouaoui Jamal

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 6

392--400

EN

In Morocco, agriculture is an important sector that contributes to the country’s economy and food security. Accurately predicting crop yields is crucial for farmers, policy makers, and other stakeholders to make informed decisions regarding resource allocation and food security. This paper investigates the potential of Machine Learning algorithms for improving the accuracy of crop yield predictions in Morocco. The study examines various factors that affect crop yields, including weather patterns, soil moisture levels, and rainfall, and how these factors can be incorporated into Machine Learning models. The performance of different algorithms, including Decision Trees, Random Forests, and Neural Networks, is evaluated and compared to traditional statistical models used for crop prediction. The study demonstrated that the Machine Learning algorithms outperformed the Statistical models in predicting crop yields. Specifically, the Machine Learning algorithms achieved mean squared error values between 0.10 and 0.23 and coefficient of determination values ranging from 0.78 to 0.90, while the Statistical models had mean squared error values ranging from 0.16 to 0.24 and coefficient of determination values ranging from 0.76 to 0.84. The Feed Forward Artificial Neural Network algorithm had the lowest mean squared error value (0.10) and the highest R² value (0.90), indicating that it performed the best among the three Machine Learning algorithms. These results suggest that Machine Learning algorithms can significantly improve the accuracy of crop yield predictions in Morocco, potentially leading to improved food security and optimized resource allocation for farmers.

2

Scheduling with the Probabilistic Coupling Method I (PTCM I) - assuming the continuity of work of working teams

Kostrzewa-Demczuk Paulina, Rogalska Magdalena

Archives of Civil Engineering

|

2023

|

Vol. 69, nr 2

455--469

EN

Modeling and numerical analysis of the design of building structures, their technology, organization and management methods of construction processes are the subject of the work of many scientists in Poland. Schedule designers try to best reflect the reality of construction projects with the available methods, although this procedure is not always successful. One of the scheduling methods is the Time Coupling Methods (TCM), which can be refined using the predictive durations of the Multivariate Method of Statistical Models (MMSM) construction processes and standard deviations. A new scheduling method in the probabilistic approach was developed - Probabilistic Time Couplings Method I (PTCM I). At PTCM I, work is organized in such a way as to maintain the continuity of work of employees, as downtime of workers is disadvantageous and costly. The total duration of the new investment was forecasted and compared with the other methods of scheduling and with real time after its completion. The results clearly show that the developed methodology can be successfully used in scheduling construction works.

PL

Modelowanie i analiza numeryczna projektowania konstrukcji budowlanych, ich technologii, organizacji i metod zarządzania procesami budowlanymi są przedmiotem pracy wielu naukowców w Polsce. Projektanci harmonogramów starają się jak najlepiej odzwierciedlić realia projektów budowlanych dostępnymi metodami, choć procedura ta nie zawsze jest skuteczna. Jedną z metod planowania jest metoda Time Coupling Methods (TCM), którą można udoskonalić za pomocą predykcyjnych czasów trwania procesów konstrukcji wielowymiarowej metody modeli statystycznych (MMSM) i odchyleń standardowych. Opracowano nową metodę szeregowania w podejściu probabilistycznym - Probabilistic Time Couplings Method I (PTCM I). W PTCM I praca jest zorganizowana w taki sposób, aby zachować ciągłość pracy pracowników, gdyż przestoje pracowników są niekorzystne i kosztowne. Prognozowano łączny czas trwania nowej inwestycji i porównano ją z innymi metodami harmonogramowania oraz z czasem rzeczywistym po jej zakończeniu. Wyniki jednoznacznie pokazują, że opracowaną metodykę można z powodzeniem zastosować w harmonogramowaniu robót budowlanych.

3

Failure model for unidirectional composite element

Gutans Juris, Zagulski Piotr, Verzemnieks Druvis, Kleinhofs Martins

Composites Theory and Practice

|

2022

|

R. 22, nr 1

58--61

EN

This paper is devoted to important issues of determining the strength and predicting the failure processes of composites. These issues enable determination of the limits of safe use of a product and the recognition of when limits are reached. It investigates the distribution function of the composite and its components. The developed model that is presented in this paper enables description of not only the predictable strength of unidirectional composites, but also the character of the failure, taking into account the fiber stress and/or ultimate strain distribution.

PL

Artykuł poświęcony jest ważnym zagadnieniom wyznaczania wytrzymałości i przewidywania procesów destrukcyjnych kompozytów. Kwestie te pozwalają na określenie granic bezpiecznego użytkowania produktu i rozpoznania, kiedy limity zostały osiągnięte. Zbadano dystrybuantę kompozytu i jego komponentów. Opracowany model przedstawiony w niniejszej pracy pozwala opisać nie tylko przewidywalną wytrzymałość kompozytów jednokierunkowych, ale także charakter zniszczenia, z uwzględnieniem naprężeń włókien i/lub rozkładu odkształceń końcowych.

4

Prediction of backbreak in the blasting operations using artificial neural network (ANN) model and statistical models (case study: Gol-e-Gohar iron ore mine No. 1)

Sirjani Abbas Khajouei, Sereshki Ferhang, Ataei Mohammad, Hosseini Mohammad Amir

Archives of Mining Sciences

|

2022

|

Vol. 67, no. 1

107--121

EN

Backbreak is an undesirable phenomenon in blasting operations, which can bedefined as the undesirable destruction of rock behind the last row of explosive holes. To prevent and reduce its adverse effects, it is necessary to accurately predict backbreak in the blasting process. For this purpose, the data obtained from 66 blasting operations in Gol-e-Gohar iron ore mine No. 1 considering blast pattern design Parameters and geologic were collected. The Pearson correlation results showed that the parameters of the hole height, burden, spacing, specific powder, number of holes, and the uniaxial compressive strength had a significant effect on the backbreak. In this study, a multilayer perceptron artificial neural network with the 6-12-1 architecture and six multiple linear and nonlinear statistical models were used to predict the backbreakin the blasting operations. The results of this study demonstrated that the prediction rate of backbreak using the artificial neural network model with R2 = 0.798 and the rates of MAD, MSE, RMSE and, MAPE were0.79, 0.93, 0.97 and, 11.63, respectively, showed fewer minor error compared to statistical models. Based on the sensitivity analysis results, the most important parameters affecting the backbreak, including the hole height, distance between the holes in the same row, the row spacing of the holes, had the most significant effect on the backbreak, and the uniaxial compressive strength showed the lowest impact on it.

5

Real estate valuation algorithm for large local markets

Bitner Agnieszka, Frosik Małgorzata

Advances in Geodesy and Geoinformation

|

2022

|

Vol. 71, no. 1

art. no. e20, 2022

EN

The article deals with issues related to the application of statistical methods used in the valuation process. The proposed algorithm for real estate valuation can be used in the statistical market analysis method in the process of mass appraisal. The algorithm uses a multiple linear regression model. Legal considerations indicate the need for such an algorithm for the determination of the value of representative properties. Due to the large size of the database of comparables, the proposed algorithm can be used only to appraise typical properties. A good statistical model is parsimonious, that is, it uses as few mathematical concepts as possible in a given situation. A model should extract what is systematic in the results observed, allowing for the presence of purely random deviations. The article discusses the basic principles of building a good statistical model. Attention is drawn to the number of market attributes that are entered into the model and the range of their values. As few explanatory variables as possible should be entered into the model to explain the phenomenon under study. Explanatory variables are only those characteristics of the property that differentiate prices in a given market defined and adopted by the appraiser as the basis for valuation. The article highlights the importance of taking into account market changes during the period under study.

6

Study on the Influence of Roadways on Land Plots according to the Results of Monetary Evaluation

Shulgan Roman, Yanchuk Oleksandr, Pakharenko Olha, Pryshchepa Alla

Geomatics and Environmental Engineering

|

2021

|

Vol. 15, no. 3

5--21

EN

The paper examines the impact of highways of urban significance on surrounding areas. The authors substantiated the size of the road effect zone. In order to determine the quantitative extent of the impact of highways on surrounding areas, the scholars applied the data regarding the selling prices of land plots with various designated purpose, i.e. the estimated money value of land is the indicator of determining the road effect on surrounding areas. Since a great number of factors affects the value of these land plots, in order to determine the road effect for highways, the authors developed economic and statistical models for expert value of land plots with various designated purpose using the method of multiple regression analysis. After substituting different values of distances to a highway within the road effect zone in the model, the researchers established the patterns of change in the value of land plots with various designated purpose and calculated the adjustment factors that can be used in the pecuniary valuation of land plots. The value of such coefficients for residential construction land is 0.85–1.00; for commercial land it is 1.00–1.17; and for industrial land it is 1.00–1.01.The paper examines the impact of highways of urban significance on surrounding areas. The authors substantiated the size of the road effect zone. In order to determine the quantitative extent of the impact of highways on surrounding areas, the scholars applied the data regarding the selling prices of land plots with various designated purpose, i.e. the estimated money value of land is the indicator of determining the road effect on surrounding areas. Since a great number of factors affects the value of these land plots, in order to determine the road effect for highways, the authors developed economic and statistical models for expert value of land plots with various designated purpose using the method of multiple regression analysis. After substituting different values of distances to a highway within the road effect zone in the model, the researchers established the patterns of change in the value of land plots with various designated purpose and calculated the adjustment factors that can be used in the pecuniary valuation of land plots. The value of such coefficients for residential construction land is 0.85–1.00; for commercial land it is 1.00–1.17; and for industrial land it is 1.00–1.01.

7

A statistical study of COVID-19 pandemic in Egypt

Radwan Taha

Demonstratio Mathematica

|

2021

|

Vol. 54, nr 1

233--244

EN

The spread of the COVID-19 started in Wuhan on December 31, 2019, and a powerful outbreak of the disease occurred there. According to the latest data, more than 165 million cases of COVID-19 infection have been detected in the world (last update May 19, 2021). In this paper, we propose a statistical study of COVID-19 pandemic in Egypt. This study will help us to understand and study the evolution of this pandemic. Moreover, documenting of accurate data and taken policies in Egypt can help other countries to deal with this epidemic, and it will also be useful in the event that other similar viruses emerge in the future. We will apply a widely used model in order to predict the number of COVID-19 cases in the coming period, which is the autoregressive integrated moving average (ARIMA)model. This model depicts the present behaviour of variables through linear relationship with their past values. The expected results will enable us to provide appropriate advice to decision-makers in Egypt on how to deal with this epidemic.

8

Costs of facade systems execution

Leśniak Agnieszka, Wieczorek Damian, Górka Monika

Archives of Civil Engineering

|

2020

|

Vol. 66, nr 1

81--95

EN

Cost estimation in the pre-design phase both for the contractor as well as the investor is an important aspect from the point of view of budget planning for a construction project. Constantly growing commercial market, especially the one of public utility constructions, makes the contractor, at the stage of development the design concept, initially estimate the cost of the facade, e.g. office buildings, commercial buildings, etc., which are most often implemented in the form of aluminum-glass facades or ventilated elevations. The valuation of facade systems is of an individual calculation nature, which makes the process complicated, time-consuming, and requiring a high cost estimation work. The authors suggest using a model for estimating the cost of facade systems with the use of statistical methods based on multiple and stepwise regression. The data base used to form statistical models is the result of quantitative-qualitative research of the design and cost documentation of completed public facilities. Basing on the obtained information, the factors that shape the costs of construction façade systems were identified; which then constitute the input variables to the suggested cost estimation models.

PL

Celem artykułu jest próba oszacowania kosztów wykonania systemów elewacyjnych obiektów użyteczności publicznej z wykorzystaniem modeli matematycznych, a w szczególności regresji wielorakiej oraz regresji krokowej postępującej. Dane użyte do budowy funkcji regresji zostały opracowane przez autorów na podstawie analizy dokumentacji projektowych, wykonawczych i kosztorysowych obiektów użyteczności publicznej. Opracowano bazę danych zawierającą główne czynniki wpływające na kształtowanie się kosztów wykonania systemów elewacyjnych obiektów użyteczności publicznej. Systemy elewacyjne realizowane były w formie fasad aluminiowo-szklanych oraz elewacji wentylowanych.

9

Application of multidimensional statistical model for evaluation of measured data obtained from testing of the hcci engine prototype

Puškár M., Fabian M., Tomko T.

Diagnostyka

|

2018

|

Vol. 19, No. 1

19--24

EN

Evaluation of the measured data, which are obtained from testing of the HCCI engine prototype, is a complex process taking into consideration questions of the vibration diagnostics. The complexity of this procedure is caused due to a necessity to evaluate a large amount of the various data. One of the solution possibilities is application of a multidimensional statistical model within the evaluation process in order to obtain more accurate information about the actual operational condition concerning the analysed engine.

10

Probabilistic and Statistical Modelling of the Harmful Transport Impurities in the Atmosphere from Motor Vehicles

Wojcik W., Adikanova S., Malgazhdarov Y. A., Madiyarov M. N., Myrzagaliyeva A. B., Temirbekov N. M., Junisbekov M., Pawłowski L.

Rocznik Ochrona Środowiska

|

2017

|

Tom 19

795--808

EN

The aim of the work is to create a mathematical model for the distribution of emissions from vehicles. In this article, it was proposed to use the probabilistic and statistical approach for modelling the distribution of harmful impurities in the atmosphere from vehicles using the example of the Ust-Kamenogorsk city. Using a simplified methodology of stochastic modelling, it is possible to construct effective numerical computational algorithms that significantly reduce the amount of computation without losing their accuracy.

PL

Celem pracy jest stworzenie matematycznego modelu rozprzestrzeniania się zanieczyszczeń z pojazdów. W tym artykule zaproponowano zastosowanie podejścia probabilistycznego i statystycznego do modelowania rozprzestrzeniania się szkodliwych zanieczyszczeń w atmosferze z pojazdów na przykładzie miasta Ust-Kamenogorsk. Stosując uproszczoną metodologię modelowania stochastycznego, można konstruować skuteczne numeryczne algorytmy obliczeniowe, które znacznie redukują ilość obliczeń bez utraty dokładności.

11

Związek pomiędzy wskaźnikiem desorpcji i metanonośnością dla pokładów kopalni ,,Borynia-Zofiówka-Jastrzębie” Ruch Zofiówka – przybliżona zawartość metanu w węglu

Dutka B., Wierzbicki M.

Prace Instytutu Mechaniki Górotworu PAN

|

2017

|

T. 19, nr 3

11--20

PL

Przeprowadzono badania statystyczne dla 24 pokładów kopalni ,,Borynia-Zofiówka-Jastrzębie” Ruch Zofiówka polegające na statystycznej analizie związku występującego pomiędzy mierzonymi w warunkach in situ wartościami wskaźnika desorpcji dp oraz metanonośnością pokładu Mn. Zbiory danych obejmowały wyniki pomiarów kopalnianych prowadzonych na obszarze górniczym ,,Zofiówki” w latach 2007-2014. Zgodnie z obowiązującą metodą desorbometryczną, zależność pomiędzy wartościami wskaźnika desorpcji i metanonośnością przybliżoną uśrednia funkcja liniowa, która obowiązuje dla wszystkich polskich kopalń. W obrębie poszczególnych pokładów kopalni wyznaczono wartości współczynnika korelacji Pearsona oraz przeprowadzono badanie siły korelacji i jej istotności. Posługując się metodą regresji liniowej, określono indywidualne równania opisujące zależność pomiędzy parametrami Mn i dp dla różnych pokładów Ruchu Zofiówka. Zgodnie z przeprowadzoną analizą można zauważyć, że relacja pomiędzy wskaźnikiem desorpcji i metanonośnością nie jest stała, lecz zmienia się w zależności od pokładu. Uzyskane rezultaty pozwalają przypuszczać, że zmienność relacji Mn-dp może wynikać ze zmian właściwości sorpcyjnych pokładów charakteryzujących się różnym wiekiem geologicznym. Zagadnienie to będzie przedmiotem dalszych prac.

EN

Statistical studies for 24 coal seams of the Borynia-Zofiówka-Jastrzębie mine, Zofiówka Section have been carried out. Studies consisted of statistical analysis of the relationship between in situ measured values of the desorption intensity index dp and the methane content Mn. Data sets included the results of measurements of these parameters in the years 2007-2014 in the Zofiówka mining area. According to the desorbometric method, the relationship between values of desorption intensity index and approximate methane content of coal averages the linear function, which applies to all Polish hard coal mines. The Pearson correlation coefficients, the correlation strength and its significance were determined within particular coal seams of Zofiówka mining area. Using the linear regression method, individual equations describing the Mn(dp) dependence for different coal seams were determined. According to the analysis, it is noted that the relationship between the desorption intensity index and the methane content is not constant, but varies for different coal seams. The obtained results suggest that the variability of the Mn(dp) relationship may be due to changes in the sorption properties of coal seams with different geological ages. This issue will be the subject of further work.

12

Local crystalline structure of multinary semiconducting alloys : Random vs. ordered distributions

Kisiel A., Robouch B. V., Marcelli A.

Opto-Electronics Review

|

2017

|

Vol. 25, No. 3

242--250

EN

A description of the status of the art of experimental and theoretical investigations of local crystalline structures of tetrahedron ordered ternary and quaternary semiconducting alloys is presented. Experimental EXAFS data and FTIR analysis are summarized and analyzed using both the Rigid Network Cations theoretical model and the Strained-tetrahedra model. Internal preferences of ion pairs in ternary and qua-ternary alloys are discussed. Several ternary systems of different structures show ideal quasi-canonical Bernoulli distributions, while others are characterized by extreme preferences in which one, several or even all configurations are depressed or even lacking. The results demonstrate that the validity of the Bernoulli distribution is limited and not fulfilled in many systems. This article is an expanded version of the scientific reports presented at the International Conference on Semiconductor Nanostructures for Optoelectronics and Biosensors 2016 ICSeNOB2016, May 22–25, 2016, Rzeszow, Poland.

13

Condensation polymerization of AB2 monomers – modeling and validation of model of polyreaction performed at the room temperature

Ryczek A., Lechowicz J. B., Walczak M., Galina H.

Polimery

|

2016

|

T. 61, nr 11-12

780--787

EN

Statistical and kinetic methods to model step polymerization of AB2 type of monomers (A and B stand for functional groups) are briefly reviewed and the relationships linking conversion or reaction time with averages of polymerization degree are derived for systems fulfilling the Flory-Stockmayer assumptions, i.e., for those with no reactivity changes of functional groups and absence of intramolecular linking. Results of kinetic studies are also presented for polymerization of 3,5-diaminobenzoic acid, aided with N,N'-diisopropylcarbodiimide, carried out at room temperature in NMR test tubes. For reaction carried out in dimethylsulphoxide, the relationship between conversion and time is well described by the simplest kinetic model. It was stated that in the case of reaction carried out in dimethylformamide the reactivity of the second amino group in the monomeric units seems to be ten times lower than that of the first one.

PL

Przedstawiono krótki przegląd statystycznych i kinetycznych metod modelowania stopniowej polimeryzacji monomerów typu AB2 (A i B reprezentują grupy funkcyjne). Wyprowadzono relacje łączące stopień przereagowania ze średnimi stopniami polimeryzacji dla układów reagujących zgodnie z założeniami Flory'ego i Stockmayera, tj. bez zmian w reaktywnościach grup funkcyjnych oraz nieobecności wiązań wewnątrzcząsteczkowych. Przedstawiono wyniki badań kinetycznych przebiegu polimeryzacji kwasu 3,5-diaminobenzoesowego wspomaganej N,N'-diizopropylokarbodiimidem, którą prowadzono w temperaturze pokojowej w probówkach NMR. Kinetykę badanej reakcji, prowadzonej w dimetylosulfotlenku, dobrze opisuje najprostszy model kinetyczny polikondensacji. Stwierdzono, że w przypadku reakcji prowadzonej w dimetyloformamidzie, reaktywność drugiej grupy aminowej w jednostkach monomerycznych jest dziesięciokrotnie mniejsza, niż reaktywność pierwszej z tych grup.

14

Modelling the Effect of Weave Structure and Fabric Thread Density on Mechanical and Comfort Properties of Woven Fabrics

Maqsood M., Nawab Y., Shaker K., Umair M., Ashraf M., Baitab D. M., Hamdani S. T. A., Shahid S.

Autex Research Journal

|

2016

|

Vol. 16, no. 3

160--164

EN

The paper investigates the effects of weave structure and fabric thread density on the comfort and mechanical properties of various test fabrics woven from polyester/cotton yarns. Three different weave structures, that is, 1/1 plain, 2/1 twill and 3/1 twill, and three different fabric densities were taken as input variables whereas air permeability, overall moisture management capacity, tensile strength and tear strength of fabrics were taken as response variables and a comparison is made of the effect of weave structure and fabric density on the response variables. The results of fabric samples were analysed in Minitab statistical software. The coefficients of determinations (R-sq values) of the regression equations show a good predictive ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of woven fabrics to attain specific comfort and mechanical properties.

15

A nonlinear statistical approach for damping uncertainty propagation in structural dynamics

Tiliouine B., Chemali B.

Archives of Civil Engineering

|

2016

|

Vol. 62, nr 1

11--24

EN

The object of the present study is to investigate the influence of damping uncertainty and statistical correlation on the dynamic response of structures with random damping parameters in the neighbourhood of a resonant frequency. A Non-Linear Statistical model (NLSM) is successfully demonstrated to predict the probabilistic response of an industrial building structure with correlated random damping. A practical computational technique to generate first and second-order sensitivity derivatives is presented and the validity of the predicted statistical moments is checked by traditional Monte Carlo simulation. Simulation results show the effectiveness of the NLSM to estimate uncertainty propagation in structural dynamics. In addition, it is demonstrated that the uncertainty in damping indeed influences the system response with the effects being more pronounced for lightly damped structures, higher variability and higher statistical correlation of damping parameters.

PL

Nieliniowy Model Statystyczny (NLSM) jest opracowany, aby skutecznie rozpowszechniać niepewność tłumienia w analizach dynamicznych, w celu przewidywania statystyki drugiego rzędu dla probabilistycznej odpowiedzi konstrukcji ze skorelowanymi parametrami tłumienia. Waga tłumienia losowego ze skorelowanymi parametrami oraz ich wpływ na wrażliwość szczytowej odpowiedzi konstrukcyjnej, omawiane są w świetle znaczących zakresów niepewności tłumienia oraz współczynników korelacji. Dodatkowo, wpływ korelacji statystycznej tłumienia na granice przybliżenia Liniowego Modelu Statystycznego (LSM) oraz na NLSM badany jest za pomocą Symulacji Monte Carlo.

16

Statistical models for the estimation of execution time of coarsegrained OpenMP programs

Kamińska A., Bielecki W.

Przegląd Elektrotechniczny

|

2015

|

R. 91, nr 2

22-26

EN

This paper presents a family of statistical models for the estimation of program execution time. The paper discusses the possibilities of how to apply the family to reduce iterative compilation duration and in consequence, software development duration. The discussion is supported with the results of experimental research carried out for program loops selected from the NAS Parallel Benchmarks test suite.

PL

W artykule przedstawiono autorską koncepcję rodziny modeli statystycznych do oszacowania czasu wykonania programu oraz omówiono możliwości wykorzystania jej w celu skrócenia czasu wykonywania kompilacji iteracyjnej (a w konsekwencji czasu wytwarzania oprogramowania). Przedstawiono także wyniki przeprowadzonych badań eksperymentalnych.

17

A DDoS Attacks Detection Based on Conditional Heteroscedastic Time Series Models

Andrysiak T., Saganowski Ł., Maszewski M., Grad P.

Image Processing & Communications

|

2015

|

Vol. 20, no. 1

23--33

EN

Dynamic development of various systems providing safety and protection to Network infrastructure from novel, unknown attacks is currently an intensively explored and developer domain. In the present article there is presented an attempt to redress the problem by variability estimation with the use of conditional variation. The predictions of this variability were based on the estimated conditional heteroscedastic statistical models ARCH, GARCH and FIGARCH. The method used for estimating the parameters of the exploited models was determined by calculating maximum likelihood function. With the use of compromise between conciseness of representation and the size of estimation error there has been selected as a sparingly parameterized form of models. In order to detect an attack-/anomaly in the network traffic there were used differences between the actual network traffic and the estimated model of the traffic. The presented research confirmed efficacy of the described method and cogency of the choice of statistical models.

18

Linking process variables and newsprint properties in Mazandaran Wood and paper Industries

Hadi Moradian M., Resalati H.

Polish Journal of Chemical Technology

|

2014

|

Vol. 16, nr 1

110-116

EN

Pulp and paper industries have provided great research opportunities to control systems. The objective of this study was to investigate the relationships between 80 process variables of CMP tower and stock preparation, and 17 newsprint quality properties in Mazandaran Wood and Paper Industries (MWPI). After the preparation of two suitable data series considering the time needed for pulp to paper, the relations between process dependent and newsprint independent variables were determined using partial least squares (PLS) regression. As a result, two PLS models were developed. The first model with 4 latent vectors categorized and related CMP tower variables and the second one, through 8 latent vectors connected stock preparation variables with paper properties. PLS regression coefficients determined how much the most influencing process variables impact each paper properties.

19

Teoria informacji a statystyka matematyczna

Inglot T.

Mathematica Applicanda

|

2014

|

Vol. 42, No. 1

115--174

PL

W niniejszym artykule przedstawiony jest zarys teorii informacji z probabilistycznego i statystycznego punktu widzenia. Ten nurt teorii informacji rozwijał się intensywnie w ostatnich dziesięcioleciach. Wpłynął tez w znaczący sposób na rozwój metod statystycznych. Celem artykułu jest wprowadzenie czytelnika w przystępny sposób w podana powyżej tematykę, dostarczenie mu pewnych intuicji i przybliżenie specyfiki podejścia teorio-informacyjnego w statystyce matematycznej.

EN

In the paper we present an outline of the information theory from the probabilistic and statistical point of view. Such a direction of the information theory has been intensively developed in recent decades and significantly influenced a progress in the statistical methodology. The aim of the article is to introduce the reader into these problems, provide some intuitions and acquaint with a specific information-theoretic approach to the mathematical statistics. The first part of the paper is devoted to brief and easy of approach introduction to the main notions of the information theory like entropy, relative entropy (Kullback- Leibler distance), information projection and Fisher information as well as presentation of their most important properties including de Bruijn’s identity, Fisher information inequalities and entropy power inequalities. In the short second part we give applications of the notions and results from the first part to limit theorems of the probability theory such as the asymptotic equipartition property, the convergence of empirical measures in the entropy distance, large deviation principle with emphasis to Sanov theorem, the convergence of distributions of homogeneous Markov chains in the entropy distance and the central limit theorem. The main, last part of the article shows some most significant and important applications of the information theory to the mathematical statistics. We discuss connections of the maximum likelihood estimators with the information projections and the notion of sufficient statistic from the information-theoretic point of view. The problems of source coding, channel capacity and an amount of information provided by statistical experiments are presented in a statistical framework. Some attention is paid to the expansion of Clarke and Barron and its corollaries e.g. in density estimation. Next, applications of the information theory to hypothesis testing is discussed. We give the classical Stein’s Lemma and its generalization to testing composite hypothesis obtained by Bahadur and show their connections with the asymptotic efficiency of statistical tests. Finally, we briefly mention the problem of information criteria in a model seletion including the most popular two-stage minimal description length criterion of Rissanen. The enclosed literature is limited only to papers and books which are referred to in the paper.

20

Modele statystyczne procesów logistycznych dla potrzeb ich oceny i kontroli

Alot Z.

Logistyka

|

2014

|

nr 3

34--43

PL

Artykuł jest wynikiem badań nad identyfikacją modeli procesów produkcyjnych w warunkach założeń nieklasycznych dla potrzeb zarządzania jakością wyrobów. Przedstawiono w nim propozycje zastosowania modeli wykorzystywanych w statystycznym sterowaniu procesami do oceny i kontroli procesów logistycznych. Omówiono klasyczny model i wskaźniki przyjmujące za punkt wyjścia założenie o rozkładzie normalnym cech procesu. Zaproponowano własną klasyfikację i wynikający z niej zbiór modeli dający możliwość bardziej precyzyjnego wyznaczania ich zdolności. Klasyfikacja ta wynika z zaleceń normy ISO 21747:2006 wprowadzającej modele dla procesów niestacjonarnych. Scharakteryzowano metody wyznaczania wydajności procesu w przypadku tej klasy procesów.

EN

This paper is the result of research for identification of production processes models in terms of nonclassical assumptions for the quality management of products. It sets out propositions for the use of the models used in statistical control of the processes for the evaluation and control of logistic processes. It’s discussed the classical model and indicators taking as a starting point the assumption of a characteristics normal distribution of the process. Own classification was proposed with set of models resulting from it giving the possibility for a more precise determination of their ability. This classification follows the recommendations of ISO 21747:2006 norm introducing models for non-stationary processes. Methods for determining the performance of the process in case of this class of the processes were characterized.