BazTech - Yadda

1

The influence of mineral additives and sands on the performance of self-compacting sand concretes

Djoual Belkacem, Kettab Ratiba Mitiche, Ghrieb Abderrahmane, Bouziani Tayeb, Zaitri Rebih

Advances in Materials Science

|

2024

|

Vol. 24, nr 1(79)

104--126

EN

The chosen plan for our case study is a network mixture design consisting of 21 mixtures. The application of this method has proven to be immensely useful in studying the influence of composition parameters (composite design) and the utilization of various types of mineral additives (mixture design). The application of the Design of Experiments (DOE) method, based on a statistical approach, allowed for a better understanding of the effect of formulation parameters, including the proportion of alluvial sand (75%), dune sand (25%), the total amount of sand kept at constant percentages, the dosages of brick powder, limestone filler and ceramic powder (all varying from 0 %, 20 %, 40 %, 60 %, 80 %, and 100 %), while keeping the dosage of superplasticizer and the water/binder ratio constant. This approach helped to understand the interactions between these parameters and their impact on the process. Mathematical models relating the variations of these parameters to the workability and compressive strength of such concrete mixtures have been established. The results obtained show that the workability of SCSC (expressed by slump flow and V-funnel flow) improves with the increase in the dosage of limestone filler (FC), brick powder (PB), and ceramic powder (PC), with element having a different impact, be it alone or in a combination. Moreover, they all improved the behavior of SCSC in both the fresh and hardened states. The experiment shows that increasing the proportions of FC and PC in the mixture, whether linear, binary, or ternary, leads to a significant improvement in compressive strength. Furthermore, better strength is observed in the ternary mixture at 28 days, with a strength of 43 MPa, with the following proportions (FC 70%, PB 20%, PC 10%). Finally, the result at 180 days of 48 MPa confirms the following proportions (PC 60 %, FC 30 %, PB 10 %) The compliance of some SCSC compositions was tested according to the recommendations of the French Association of Civil Engineering.

2

Assessment of the production process organization in the metal industry - case study

Mielczarek Krzysztof

System Safety : Human - Technical Facility - Environment

|

2023

|

Vol. 5, iss. 1

266--275

EN

The article provides a detailed case study illustrating the practical application of BOST surveys while focusing on the third principle of Toyota. This particular principle underscores the importance of achieving an even distribution in production to mitigate fluctuations and ensure the smooth functioning of the production process. The article delves into a comprehensive analysis of how this principle is implemented in real-world scenarios, exploring its effects on production efficiency and elucidating the advantages gained from the elimination of downtime and the prevention of excessive inventory buildup. Moreover, the article offers a discussion on examples of applications across various industries, shedding light on practical strategies for implementing the third Toyota principle. The goal is to not only optimize production processes but also enhance flexibility and adaptability to evolving demand patterns. The article concludes by examining the pivotal role of this principle within the broader context of operational excellence and the development of more efficient production systems. The research in focus centers around a company operating in the metal industry. Through the utilization of BOST questionnaire surveys, production workers within the company expressed their perspectives, revealing which factors they deemed most crucial. The analysis of research results takes various forms, including tables, histograms, radar charts, and several statistical tools. The overarching objective of this analysis is to identify and present the most critical factors by constructing significance sequences based on the obtained results. The findings obtained for small and medium-sized enterprises align with results from similar tests conducted in different business settings, indicating a level of consistency and applicability across various organizational contexts.

3

Zanieczyszczenie powietrza w opiniach młodzieży na podstawie badań z użyciem metod i narzędzi statystyki matematyczne

Kosman Jolanta, Mroczyńska Karolina

Rynek Energii

|

2023

|

Nr 6

71--80

PL

Polska należy do państw o najbardziej zanieczyszczonym powietrzu w Europie. Jest w ścisłej czołówce krajów europejskich ze względu na osiągane poziomy stężeń pyłów zawieszonych PM10 i PM2,5 oraz notuje najwyższe w Unii Europejskiej stężenia średnioroczne kancerogennego i mutagennego benzo(a)pirenu. Główną przyczyną złej jakości powietrza jest spalanie węgla i drewna w małych instalacjach grzewczych (domowych piecach, kotłach, kominkach itp.). Do rozwiązania tego problemu konieczne jest powszechne stosowanie niskoemisyjnych i zeroemisyjnych, w tym odnawialnych źródeł energii. Bardzo ważny jest także wysoki poziom wiedzy i świadomości ekologicznej oraz akceptacja społeczna dla działań naprawczych, także wśród młodzieży. W związku z tym w marcu 2023 r. w Bydgoszczy, która również zmaga się z problemem złej jakości powietrza (w mieście znajduje się około 20 tys. źródeł ciepła na paliwa stałe, dane z dnia 23.02.2023), przeprowadzono badanie ankietowe, którego celem było sprawdzenie poziomu wiedzy i świadomości ekologicznej młodzieży w zakresie zanieczyszczenia powietrza, w tym także prawnych narzędzi walki ze smogiem – lokalnych uchwał antysmogowych. Bezpośrednim impulsem do przeprowadzenia tych badań był nadchodzący termin wprowadzenia kluczowych zapisów uchwały antysmogowej w województwie kujawsko-pomorskim, tj. zakazu używania instalacji grzewczych poniżej trzeciej klasy, w których spalane są paliwa stałe z dniem 01.01.2024. Do analizy wyników i we wnioskowaniu zastosowano metody i narzędzia statystyki matematycznej (test niezależności chi kwadrat oraz współczynniki: V Cramera, C Pearsona i φ Yule’a).

EN

Poland is one of the countries with the most polluted air in Europe. It is among the leading European countries due to the levels of PM10 and PM2.5 particulate matters concentrations achieved, and it records the highest average annual concentrations of the carcinogenic and mutagem'c benzo(a)pyrene in the European Union. The main cause of poor air quality is the burning of coal and wood in small heating installations. To solve this problem, it is necessary to widely use low- and zero-emission energy sources, including renewable energy sources. A high level of knowledge and ecological awareness as well as social acceptance for remedial actions, also among young people, are also very important. Therefore, in March 2023, a survey was conducted in Bydgoszcz, which is also struggling with the problem of poor air quality (the city has about 20,000 solid fuel heat sources, data from 23.02.2023). Its aim was to check the level of knowledge and ecological awareness of young people in the ﬁeld of air pollution, including legal tools to ﬁght smog - local anti-smog resolutions. The direct impulse to conduct this research was the upcoming date of introduction of the key provisions of the anti-smog resolution in the Kuyavian-Pomeranian Voivodeship, i.e. the ban on the use of heating installations below the third class in which solid fuels are burned as of 01.01.2024. Methods and tools of mathematical statistics were used to analyze the results and draw conclusions (the chi-square test of independence and the following coefﬁcients: Cramer's V, Pearson's C and Yule's (p).

4

Rozszerzona analiza statystyczna wyników pomiarów natężenia promieniowania słonecznego

Torbus Sławomir Andrzej, Mroczyńska Karolina, Kreft-Korda Joanna, Grabarczyk Sławomir

Rynek Energii

|

2023

|

Nr 1

35--39

PL

W niniejszej pracy przedstawiono koncepcję rozszerzonej analizy statystycznej wyników pomiarów (dyskretnych sygnałów pomiarowych o charakterze losowym). Sposób jej przeprowadzania zilustrowano przykładem, w którym użyto wyników pomiarów natężenia promieniowania słonecznego. Uzyskane rezultaty pozwoliły na sformułowanie własności proponowanej metody analizy statystycznej oraz wniosków dotyczących określania wpływu pary wodnej na natężenie promieniowania słonecznego, w kontekście pozyskiwania energii elektrycznej przy użyciu ogniw fotowoltaicznych.

EN

This paper presents the concept of extended statistical analysis of measurement results (discrete random measurement signals). The method of its execution is illustrated by an example in which the results of solar radiation intensity measurements were used. The obtained results allowed to formulate the properties of the proposed method of statistical analysis and drawing conclusions regarding the influence of water vapor on the intensity of solar radiation in the context of obtaining electricity with the use of photovoltaic cells.

5

Analiza stanu baterii akumulatorów w niskobudżetowym pojeździe elektrycznym

Nocoń Adrian, Kurek Tomasz

Przegląd Elektrotechniczny

|

2023

|

R. 99, nr 1

174--178

PL

Obecnie można obserwować stały wzrost zainteresowania elektromobilnością, w tym pojazdami niskobudżetowymi (np. klasy L2e). W części badawczej artykułu przedstawiono analizę zarejestrowanych napięć poszczególnych akumulatorów w czasie jazdy pojazdu niskobudżetowego. Analizowano wartości chwilowe napięć oraz energię wydawaną przez akumulatory dla dwóch układów zasilania pojazdu. Wyniki poddano analizie statystycznej i dokonano oceny skuteczności działania układu balansowania akumulatorów.

EN

Currently, we can observe a steady increase in interest in electromobility, including low-cost vehicles (e.g. L2e class). The research part of the paper presents an analysis of the recorded voltages of individual batteries while driving a low-budget vehicle. The instantaneous values of voltages and the energy spent by the batteries while driving for two power supply systems of the vehicle were analyzed. The results were analyzed statistically and the effectiveness of the battery balancing system was assessed.

6

Charakterystyka geotechniczna osadów wysoczyzny morenowej na podstawie badań kampusu SGGW w Warszawie

Rabarijoely Simon, Lech Mariusz, Bajda Marek, Markowska-Lech Katarzyna

Przegląd Budowlany

|

2023

|

R. 94, nr 5-6

152--158

PL

W artykule, na przykładzie kampusu SGGW w Warszawie, przedstawione zostały kryteria identyfikacji warstw geotechnicznych na obszarze wysoczyzny morenowej, pozwalające na bardziej wiarygodną ocenę parametrów geotechnicznych poszczególnych warstw podłoża z uwzględnieniem lokalnych uwarunkowań. W pracy wykorzystano wyniki badań terenowych, głównie CPT oraz DMT, które porównano z wynikami badań laboratoryjnych pobranych próbek gruntów. Proponowana metoda podziału warstw geotechnicznych wraz z doborem odpowiednich parametrów gruntowych dla wydzielanych warstw zakłada zastosowanie podejścia bayesowskiego.

EN

The paper presents criteria for identification of geotechnical layers in the area of moraine upland, on the example of the Warsaw University of Life Sciences Campus - SGGW, which allows a more reliable assessment of the geotechnical parameters of individual ground layers, taking into account local conditions. The paper uses the results of in situ tests, mainly CPT and DMT, which were compared with the results of laboratory tests. A Bayesian approach was used in proposing a technique for subdividing the geotechnical layers with the annotation of the relevant parameters for the separated layers.

7

Statistical methods in the analysis of strength parameters of epoxy-glass composites modified with rubber recyclate

Drewing S., Abramczyk N., Żuk D., Dyl T.

Journal of Achievements in Materials and Manufacturing Engineering

|

2023

|

Vol. 117, nr 2

71--78

EN

Purpose The article presents a statistical analysis of strength parameters of newly developed epoxy-glass composite materials modified with the addition of rubber recyclate. Design/methodology/approach Three variants of materials with a percentage of recyclate content in the composite matrix of 3%, 5%, 7% and a reference variant without the addition of recyclate were used for the study. The samples were subjected to an impact test on a ZWICK RKP 450IR-GE impact hammer. Resilience measurement values were subjected to statistical analyses at the significance level α = 95%, such as: testing the normality of distributions with the Shapiro-Wilk test, testing differences between pairs with the Student's t-test for dependent groups, and testing ANOVA differences for independent groups. Findings The Shapiro-Wilk test confirmed that the resilience variables for all tested samples were in normal distributions; therefore the highest power parametric tests were used to test the differences. Using the Student's t-test, it was confirmed that between pairs of variables in configurations: standard sample with the modified sample, there were significant statistical differences in the distribution of resilience values for all samples. ANOVA confirmed significant changes in impact strength in 10 comparison variants. Research limitations/implications The obtained test results showed that in 9 compared cases, there were significant statistical differences, and in one case, there were no significant differences. Practical implications The performed statistical analyses confirmed their significant usefulness in the process of qualification of strength parameters for materials with high anisotropy, such as composites. Originality/value The manufactured products are innovative in terms of the method of using the addition of rubber recyclate as a filler for epoxy-glass composites. The use of static methods for their study also has practical value. It optimizes the analysis methods of the results of measurements of strength parameters of new composite materials.

8

Statistical Analysis of Selected Coal Charateristics and Toxic Compounds for FGX Air-Vibrating Separation

Mijał Waldemar, Niedoba Tomasz, Polek Daria, Baic Ireneusz, Blaschke Wiesław

Inżynieria Mineralna

|

2023

|

no. 2, vol. 1

377--387

EN

Dry beneficiation methods were popular in the first part of the 20th century. In the 1930s, before World War II, dry separators were used more commonly in the United States. Currently, this method is very popular in China, the United States, India, Russia and other places where its implementation is possible. In Poland, by contrast, dry separation still remains uncommon. However, during the last 30 years, dry separators have started to be more commonly used in coal beneficiation. One example of this type of separator might be the FGX air-vibrating separator. This type of separator uses air suspension to separate heavier particles (tailings) from lighter coal grains. The process of dry separation may depend on various parameters, e.g. particle size fraction, air supply, feed parameters, etc.. This paper describes the mathematical model which shows the scope for using this separation method for coal beneficiation. Mathematical models are based on dependencies between calorific value and ash content in the samples tested as well as relations between arsenic, thallium, mercury, lead and other coal characteristics. The latter parameters are of vital importance as Polish emission standards do not have any limits for the elements mentioned above (arsenic, thallium, mercury and lead).

PL

Suche metody wzbogacania były popularne w pierwszej połowie XX wieku. Separatory suche były używane zwłaszcza przed II Wojną Światową w latach 30-ych w USA. Obecnie, metoda ta jest bardzo popularna w Chinach, USA, Indiach, Rosji oraz w innych miejscach, gdzie możliwe jest jej zastosowanie. W Polsce proces ten jest wciąż bardzo mało popularny. Podczas ostatnich 30 lat systemy wzbogacania węgla zaczęły szerzej korzystać z separatorów suchych a przykładem bardzo popularnego urządzenia tego typu jest FGX – wibracyjny stół powietrzny. Ten typ separatora korzysta z zawiesiny powietrznej w celu wydzielenia cięższych ziaren (odpadów) od lżejszych ziaren węgla. Sucha separacja może zależeć od różnych parametrów, tj. klasa ziarnowa, zasoby powietrza, parametry nadawy itp. Artykuł ten opisuje model matematyczny, który pokazuje możliwości zastosowania tej metody separacji przy wzbogacaniu węgla. Modele matematyczne oparte były na zależnościach pomiędzy wartością opałową oraz zawartością popiołu w testowanych próbkach, jak również na relacjach pomiędzy zawartościami arsenu, talu, rtęci, ołowiu i innych charakterystyk węgla. Ostatnie parametry są bardzo ważne ponieważ polskie standardy emisji nie zawierają limitów dla pierwiastków wymienionych powyżej, a więc arsenu, talu, rtęci oraz ołowiu.

9

Statistical methods for evaluating experimental data on the use of mathematical competenciesin study for a resilient economy

Petruk Vira, Prozor Olena, Sabadosh Yuliia, Baranovska Iryna, Palii Maksim, Moroz Yevheniia, Kumargazhanova Saule, Mussayeva Dinara

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

|

2023

|

T. 13, nr 2

78--85

EN

The description of the problems, solved within the statistics evaluation of the results of educational (pedagogical) experiment in resilient economy is given. Comparison of the two average samplings and hypothesis verification relative to dispersions of the two samplings are considered.It is shown the hypothesis that teaching and methodical training system of subjects of higher mathematics in technical universities, suggested on the base of the modern interactive technologies, significantly improves the quality of the base level of professional competence of future engineers. The methodsfor statistical processing of the obtained results, which very thoroughly research all the indexes which compose the suggested learning and methodical system for teaching higher mathematics in technical universities are used.

PL

Podano opis problemów rozwiązywanych w ramach statystycznej oceny wyników eksperymentu edukacyjnego (pedagogicznego)w gospodarce odpornej. Rozważa się porównanie dwóch średnich prób i weryfikację hipotezy w odniesieniu do dyspersji dwóch prób. Wykazano hipotezę, że system nauczania i szkolenia metodycznego przedmiotów matematyki wyższej na uczelniach technicznych, zaproponowany w oparciu o nowoczesnetechnologie interaktywne, znacząco poprawia jakość podstawowego poziomu kompetencji zawodowych przyszłych inżynierów. Zastosowano metody statystycznego przetwarzania uzyskanych wyników, które bardzo dokładnie badają wszystkie wskaźniki składające się na proponowany system nauczaniai metodycznego nauczania matematyki wyższej w uczelniach technicznych.

10

Analiza statystyczna danych oraz prognozy rynkowych cen energii (RCE) w Polsce z wyprzedzeniem do 1 godziny

Piotrowski Paweł, Baranowski Marcin, Bączek Adrian, Niedźwiecki Radosław

Elektro Info

|

2023

|

nr 4

81--85

PL

W artykule przedstawiono analizę statystyczną danych oraz prognozy rynkowych cen energii (RCE) z wyprzedzeniem do 1 godziny. Sformułowano wnioski końcowe z wykonanych prognoz oraz analiz statystycznych.

EN

The article presents a statistical analysis of data and forecasts of energy prices (RCE) in Poland up to 1 hour ahead. The conclusions have been drawn based on forecasts outcome and statistical analysis.

11

Estimation of fuel consumption in a jet engine based on vibration signal parameters

Szymański Grzegorz M., Cywka Bartłomiej, Mokrzan Daniel, Prokopowicz Wojciech

Combustion Engines

|

2023

|

R. 62, nr 3

13--20

EN

This paper proposes the use of vibroacoustic signal parameters to estimate the fuel consumption of a miniature GTM-400 engine. The method for testing engine vibrations is presented, followed by an analysis of the results obtained. Two vibration point measures were selected to build a fuel consumption model. The models obtained were verified, after which those that best describe the real fuel consumption of the engine were selected. The paper proves that the vibration signal, in addition to its applications in jet engine diagnostics, can be used to determine engine performance, which can contribute to reducing the complexity of construction and increasing the economics of engine operation.

12

Endoscopy, video capsule endoscopy, and biopsy for automated celiac disease detection: A review

Jahmunah V., En Wei Koh Joel, Sudarshan Vidya K., Raghavendra U., Gudigar Anjan, Lih Oh Shu, Wen Loh Hui, Faust Oliver, Datta Barua Prabal, Ciaccio Edward J., Rajendra Acharya U.

Biocybernetics and Biomedical Engineering

|

2023

|

Vol. 43, no. 1

82--108

EN

Celiac Disease (CD) is a common ailment that affects approximately 1% of the world population. Automated CD detection can help experts during the diagnosis of this condition at an early stage and bring significant benefits to both patients and healthcare providers. For this purpose, scientists have created automatic and semi-automatic CD diagnostic support systems. In this study, we performed information extraction methods that were found useful for efforts to differentiate CD versus non-CD. To focus the review process, only methods for endoscopy, video capsule endoscopy (VCE) and biopsy image analyses were considered. As described herein, we have learned that statistical and non-linear methods are most important for information extraction. These information extraction tools might benefit clinical workflows by reducing intra- and inter-observer variability. However, bias, introduced by resolving design choices during the creation of diagnostic support systems, may limit the general validity of the performance results, impacting the transferability of study outcomes. Therefore, having am overview of information extraction tools. Together with their general and specific limitations, might be assistive in improving the information extraction process. We hope our review results will provide a foundation for the design of next-generation statistical and nonlinear methods that can be used in CD detection systems. We have also compared various review articles and discussed recommendations to improve CD diagnosis. From this review, it is evident that CD diagnosis is slowly moving away from conventional techniques towards advanced deep learning techniques.

13

The effectiveness of surrogate models in predicting the long-term behavior of varying compressive strength ranges of recycled concrete aggregate for a variety of shapes and sizes of specimens

Ibrahim Aisha Kamal, Dhahir Hyfaa Yasin, Mohammed Ahmed Salih, Omar Helen Ali, Sedo Ammar Hassan

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 1

art. no. e61, 2023

EN

One of the most fundamental developments in improving the mechanical properties of concrete is the introduction of recycled coarse aggregate, which offers an environmentally preferable substitute for traditional waste management techniques. Using recycled coarse aggregate and a small number of mix proportions for the concrete components, a few studies looked at the mechanical properties of concrete. To assess the impact of recycled coarse aggregate on the long-term compressive strength of concrete at various mix proportions and different compressive strength ranges, this study analyzed four models, including linear regression (LR), nonlinear regression (NLR), pure quadratic (PQ), and full quadratic (FQ). Three datasets training, testing, and validating, each containing 314 data points culled from various studies, were used to apply the models. The recycled coarse aggregate (RA) density ranged from 0 to 1240 kg/m3, and the curing time (t) varied from 1 to 90 days. While the predicted compressive strength of the models ranged between 5 and 75 MPa, the compressive strength of the data gathered from the experimental work of several studies ranged from 8 to 78 MPa. The models’ accuracy was assessed using several metrics, including the coefficient of determination (R2), the root-mean-square error (RMSE), the scatter index (SI), the objective (OBJ), and the mean absolute error (MAE).

14

Statistical analysis and prediction of the product complaints

Knop Krzysztof, Ziora Robert

System Safety : Human - Technical Facility - Environment

|

2022

|

Vol. 4, nr 1

99-115

EN

The article presents the results of the analysis of cardboard packaging complaints based on selected quality tools and statistical tools for the purpose of a rough assessment of the effectiveness of corrective and preventive actions taken by the surveyed company and for predictive purposes. The analysis was performed in terms of two research periods - 1 year and quarters, and from the point of view of total complaints and external - customer complaints. Data on the number of products complained of as well as financial losses incurred by the company on this account were analysed. The article presents the potential of both classic quality tools and statistical tools for the purposes of in-depth analysis of complaints data and for predictive purposes and subsequent risk analysis. The critical complaint was indicated - complaint code 403 - overprint. The number of complained products to be expected in the next quarter of the new year was determined. The article shows that the corrective and preventive actions taken by the company have not yet brought the expected result in the form of reducing the number of products complained by customers during the quarters surveyed.

15

Strażnik energii dla systemów zarządzania energią elektryczną w budynkach mieszkalnych

Pilśniak Adam, Fice Marcin, Bodzek Krzysztof

Przegląd Elektrotechniczny

|

2022

|

R. 98, nr 12

92--95

PL

W artykule przedstawiono wynik analizy statystycznej zużycia energii w budynkach mieszkalnych. Za pomocą wykresów pudełkowych odwzorowano zmienność zapotrzebowania w okresach godzinowych i dobowych, która pozwoliła na określenie odchylenia standardowego w każdej godzinie w każdy dzień tygodnia. Ze względu na niedeterministyczne zachowanie mieszkańców zaproponowano aplikację „strażnik energii” pełniącą rolę systemu doradczego. System zweryfikowano dla rzeczywistych budynków mieszkalnych, każdorazowo uzyskując redukcję zużycia.

EN

Results of the statistical analyses of the residential buildings' electrical energy consumption have been presented in the article. Demand variability in hourly and daily periods has been modeled by the box plot. It allowed finding the standard deviation each hour on each day of the week. Due to the nondeterministic behavior of the inhabitants, the authors proposed an "energy guard" application as a tool acting as an advisory system. The system has been successfully verified in the real residential buildings.

16

Analiza statystyczna danych do prognozowania produkcji energii elektrycznej w wybranym systemie fotowoltaicznym

Kolańska-Płuska Joanna, Gallus Artur

Poznan University of Technology Academic Journals. Electrical Engineering

|

2022

|

No. 107

83--94

PL

W pracy przedstawiono wyniki analizy danych dostarczonych w procesie produkcji energii przez system fotowoltaiczny, które wykorzystano do prognozowania produkcji energii elektrycznej. W pracy podjęto się określenia czynników wpływających na wielkość produkcji energii. Do tego celu zostanie użyta instalacja fotowoltaiczna działająca od kwietnia do lipca 2022 r.

EN

The paper presents the results of the analysis of data provided in the process of energy production by a photovoltaic system, which were used to forecast electricity production. The work undertook to determine the factors affecting the volume of energy production. For this purpose, a photovoltaic installation operating from April to July 2022 will be used.

17

Accident analysis of mining industry in the United States - a retrospective study for 36 years

Rahimi Elham, Shekarian Younes, Shekarian Naser, Roghanchi Pedram

Journal of Sustainable Mining

|

2022

|

Vol. 21, iss. 1

27--44

EN

A retrospective study on accident analysis of the United States mines for 36 years was achieved using statistical analysis on the MSHA's accident databases between 1983 and 2018. A regression model of generalized estimation equation (GEE) was used for unbalanced panel data that provided 95,812 observations for 19,924 mine-ID-year in aggregate, coal, metal, and non-metal mines. The contributions of various parameters, including mine type, injured body part, days lost, age, and experience on the rate of accidents and injuries were investigated across the commodity types. The results showed coal miners in the East region are at a higher risk of accident. The results of regression analysis show that mine-tenured workers have a vital role in accident frequencies. Analysis of the injured body part on the injury rate indicates that the upper body injuries are the most significant among all mine types. Also, the fatality rate is significant in aggregate, and coal mines in comparison with metal and non-metal mines.

18

Analiza statystyczna danych oraz prognozy rynkowych cen energii (RCE) w Polsce z wyprzedzeniem do 24 godzin

Piotrowski Paweł, Magiera Konrad, Michalak Arkadiusz, Smoliński Mateusz

Elektro Info

|

2022

|

nr 3

20--24

PL

W artykule przedstawiono analizę statystyczną danych oraz prognozy rynkowych cen energii (RCE) z wyprzedzeniem do 24 godzin. Sformułowano wnioski końcowe z wykonanych prognoz oraz analiz statystycznych.

EN

The article presents a statistical analysis of data and forecasts of energy prices (RCE) in Poland up to 24 hours ahead. The conclusions have been drawn based on forecasts outcome and statistical analysis.

19

Analiza rozwoju liczby punktów ładowania pojazdów elektrycznych w Polsce oraz w wybranych krajach

Piotrowski Paweł, Nita Kamila

Elektro Info

|

2022

|

nr 1-2

70--74

PL

W artykule przedstawiono analizę rozwoju liczby punktów ładowania pojazdów elektrycznych w Polsce oraz wybranych krajach. Sformułowano wnioski końcowe z wykonanych analiz statystycznych.

EN

The article presents the analysis of development of the number of electric vehicle charging point in Poland and selected countries. The final conclusions have been formulated from executed statistical analysis.

20

Analiza ruchu pieszych na podstawie danych z automatycznego systemu rozpoznawania pojazdów i pieszych. Cz. 2, Analiza zależności pomiędzy badanymi parametrami

Szulecki Artur, Szagała Piotr

Drogownictwo

|

2022

|

nr 1

12--28

PL

W artykule zaprezentowano wyniki wnioskowania statystycznego, średnich czasów przejścia i czasów oczekiwania dla wszystkich wartości, które przyjmowała zmienna niezależna. Porównywanie średnich polegało na wykonaniu dla zmiennych, które przyjmowały dwie wartości, testu t Studenta oraz jednoczynnikowej analizy wariancji. W przypadku, gdy zmienna niezależna przyjmowała więcej niż dwie wartości, wykonywano jedynie jednoczynnikową analizę wariancji. Ze względu na wrażliwość obydwu metod na niejednorodność wariancji, dla każdego porównania przeprowadzano test Levene’a jednorodności wariacji.

EN

The results of statistical inference, mean crossing times and waiting times for all values that the independent variable took are presented. Comparison of means consisted of performing the Student’s t-test and one-way analysis of variance for variables that took two values. When the independent variable took more than two values, only one-way analysis of variance was performed. Because of the sensitivity of both methods to heterogeneity of variance, a Levene’s test of homogeneity of variance was performed for each comparison.