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Wyszukujesz frazę "tests" wg kryterium: Temat


Tytuł:
Internal Round Robin Tests for Operators of Mechanical Tests
Autorzy:
Madejski, B.
Powiązania:
https://bibliotekanauki.pl/articles/97809.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
internal round robin tests
tensile tests
quality system
interlaboratory tests
Opis:
For the characterisation of materials, the aeronautical industry accesses the expertise and the support of independent test laboratories. For the execution of characterisation tests of materials it is important that the test laboratory can fulfil the requirements of the testing expertly and continuously improves knowledge related to the tests. Quality systems are very helpful in this respect. One element of quality management systems is the internal round robin tests. This paper presents a procedure of teaching new operators to carry out tests. In addition, this article underlines how the importance of interlaboratory tests for finding and eliminating mistakes made by new operators. The analysis was performed for tensile tests. This test enables the assessment of operators and significantly improves the quality of tests.
Źródło:
Fatigue of Aircraft Structures; 2015, 7; 52-60
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical Tests Based on Empty Cells
Testy statystyczne oparte na pustych celach
Autorzy:
Domański, Czesław
Powiązania:
https://bibliotekanauki.pl/articles/906859.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
nonparametric tests
tests empty cells
student t-tests
Wilcoxon test
Opis:
In professional literature on statistics, a constantly growing interest is observed in non-parametric methods. Commonly these methods are based on counting, rank or position statistics and on a number or length of series. In this paper, the least popular tests, namely tests based on a number of empty cells, are presented. David-Hellwig test and a two-sample consistency test are considered. Empirical power of the tests is presented in comparison to classic tests: Kolmogorov and Shapio-Wilk test for testing normality of a distribution and t-Student’s and Wilcoxon tests for testing consistency of two distributions.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2012, 269
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
COMPUTER-ASSISTED ASSESSMENT: HIGHLIGHTS AND CHALLENGES
Autorzy:
Tahmasebi, Soheila
Rahimi, Ali
Powiązania:
https://bibliotekanauki.pl/articles/941174.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej w Lublinie. IATEFL Poland Computer Special Interest Group
Tematy:
e-assessment
mainstream tests
performance-referenced tests
ESP
Opis:
Due to the unquestionable roles of technology in language classes, it might be necessary to use computers in assessing language knowledge. This study aimed to examine how computers may be used to assess language ability of ESP students. Sixty computer-major university students at Abadan University are the participants of this study. They have taken an ESP course for a four-month academic term. To measure these participants’ ESP knowledge, two types of tests were used: a final achievement test based on course content, and a computer-assisted test based on TLU domain. The study used a computer-assisted test to highlight the validity of the final achievement test. This study also investigated ESP students’ perception of computer-supported assessment and highlighted some obstacles that may hinder e-supported activities in an Iranian context. Regarding the findings, the study points to the possibility of using computer-assisted assessment as an alternative to the present mainstream testing system.
Źródło:
Teaching English with Technology; 2013, 13, 2; 55-74
1642-1027
Pojawia się w:
Teaching English with Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tests based on run length for two samples
Testy oparte na długości serii dwóch prób
Autorzy:
Domański, Czesław
Tomaszewicz, Andrzej S
Powiązania:
https://bibliotekanauki.pl/articles/905088.pdf
Data publikacji:
1993
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
Two sample tests
runs tests
Wald-Wolfowitz test
non-parametric Wilcoxon tests
Opis:
In the practice of statistical research, tests based on the number of runs are often applied. It concerns the teste for one, two or more samples. Seldom the length of runs is applied as a test statistic. In the paper, we present a test for two samples based on the run length. Its power is compared with the t-Student parametric test, non-parametric Wilcoxon test and the Wald-Wolfowitz test based on the number of runs.
W artykule przedstawiamy pewien test hipotezy o równości dystrybuant dla przypadku dwóch'prób loáowych. Test ten oparty jest na długości serii. Moc tego tostu została porównana z empiryczny mocy parametrycznego testu t-Studenta, testu Wilcoxona, oraz mocą testu Walda-Wilcoxona opartego na liczbie serii. Załączono 12 wykresów mocy empirycznej ww. testów.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 1993, 132
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional testing of railway traffic control device
Autorzy:
Drózd, Paweł
Rosiński, Adam
Konopiński, Lech
Powiązania:
https://bibliotekanauki.pl/articles/215152.pdf
Data publikacji:
2020
Wydawca:
Instytut Kolejnictwa
Tematy:
functional tests
railway traffic control devices
tests
Opis:
The article presents the problems of functional tests of railway traffic control devices. The purpose and scope of the tests as well as the impact of testing on the SRK devices are presented. The methodology of selecting tests depending on the scope of research is proposed. For this purpose, the SRK devices were analyzed for functional and diagnostic properties.
Źródło:
Problemy Kolejnictwa; 2020, 186; 91-96
0552-2145
2544-9451
Pojawia się w:
Problemy Kolejnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The research on dynamic loads and traction properties of military vehicles in the aspect of improvement of their structures
Autorzy:
Borkowski, W.
Rybak, P.
Hryciów, Z.
Wysocki, J.
Michałowski, B.
Wiśniewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/247931.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
military vehicle
dynamic loads
traction
model tests
experimental tests
Opis:
Since the beginning of the 90’s, a scientific team in the Motor Vehicle and Transport Institute of the Mechanical Department in the Military University of Technology, has been involved in the model and experimental tests of the existing structures of the military vehicles (tanks, combat infantry vehicles and wheeled armoured carriers) in the aspect of their modernization. A part of works is related to the military vehicles included in the army’s equipment and the other parts are related to newly designed vehicles. In both cases issues related to the behaviour of selected assemblies and the whole vehicle, structure during threats posed by the reality of contemporary battlefield or armed symmetric or asymmetric conflicts are analysed. Selected effects of the tests and analyses will be presented mostly within the qualitative scope due to the data sensitivity. Contemporary design of military vehicles requires involvement of various research methods and specialized calculation software. The results obtained during performed various experimental tests make a valuable basis for verification of numerical models used in design process and multi-option simulation calculations.
Źródło:
Journal of KONES; 2015, 22, 1; 37-46
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Behaviour of cohesive soil subjected to low-frequency cyclic loading in strain-controlled tests
Autorzy:
Kalinowska, M.
Jastrzębska, M.
Powiązania:
https://bibliotekanauki.pl/articles/178956.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cohesive soils
triaxial tests
cyclic loading
strain-controlled tests
Opis:
The subject of the paper comprises tests of cohesive soil subjected to low-frequency cyclic loading with constant strain amplitude. The main aim of the research is to define a failure criteria for cohesive soils subjected to this type of load. Tests of undrained cyclic shear were carried out in a triaxial apparatus on normally consolidated reworked soil samples made of kaolinite clay from Tułowice. Analysis of the results includes the influence of number of load cycles on the course of effective stress paths, development of excess pore water pressure and stress deviator value. Observed regularities may seem surprising. The effective stress path initially moves away from the boundary surface and only after a certain number of load-unload cycles change of its direction occurs and it starts to move consequently towards the surface. At the same time, it has been observed that pore water pressure value decreases at the beginning and after few hundred cycles increases again. It is a typical behaviour for overconsolidated soil, while test samples are normally consolidated. Additionally, a similar change in deviator stress value has been observed – at first it decreases and later, with subsequent cycles, re-increases.
Źródło:
Studia Geotechnica et Mechanica; 2014, 36, 3; 21-35
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Open water manoeuvring model tests at the Joniny Test Station, Ship Hydromechanics Division, CTO S.A.
Autorzy:
Bednarek, A.
Głodowski, R.
Ołtarzewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/258688.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
free sailing model tests
manoeuvring abilities of the ship
manoeuvring tests
model tests
Opis:
Although the role of computational methods (CFD) in prediction of the hydromechanic qualities of ships grows rapidly, the role of the physical experiment is still very important (if not principal). Concerning the experimental investigations focused on manoeuvring abilities of ships, there are two main approaches to be applied: open water model tests and captive model tests (Planar Motion Mechanism). The paper contains some basic information concerning the first of mentioned methods including the evolution of the measuring techniques, applied equipment and methodology. These changes result not only from technological progress, but also reflect different expectations of our Clients. In the case of mentioned open water manoeuvring model test, its specific character determines a little bit different approach, which combines some strictly scientific objectives, i.e. prediction of the manoeuvring abilities, with commercially attractive and direct demonstration of the results. Thus, in parallel with description of the measuring systems used during the tests (starting from mechanical/optical torograph system to modern laser tachimeter system), evolution of the visualization systems is also presented. In addition, some future trends in the development of the open water tests station in Joniny has been described including experimental work as well as basic/auxiliary equipment.
Źródło:
Polish Maritime Research; 2007, S 2; 73-76
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power of tests for multivariate normality based on skewness and flatness coefficients
Moc testów wielowymiarowej normalności opartych na miarach skośności i spłaszczenia
Autorzy:
Domański, Czeslaw
Powiązania:
https://bibliotekanauki.pl/articles/907042.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
tests for multivariate normality
power of tests
quantiles of distributions of tests statistics
Opis:
There are many methods of construction of multivariate normality tests. The current review of the literature proves that there are at least 60 procedures of verification of the hypothesis about multivariate normality of variable and random distributions. We can indicate a few factors which prove an analysis of this class’s tests ascd on skewness and kurtosis measures. It is easy to notice that these tests application contributes also a better multivariate analysis of the considered variable. The paper presents results of power tests based on analytic deliberations and Monte Carlo methods.
Istnieje wiele zaproponowanych metod konstrukcji testów wielowymiarowej normalności. Aktualny przegląd literatury dowodzi, że istnieje przynajmniej 60 procedur weryfikacji hipotezy o wielowymiarowej normalności rozkładów zmiennych losowych. Kilka przesłanek uzasadnia analizę testów tej klasy, które oparte są na miarach skośności i spłaszczenia. Łatwo można spostrzec, że zastosowanie tych testów wpływa także na lepszą ogólną analizę wielowymiarową rozważanej zmiennej. W opracowaniu prezentowane są wyniki badania mocy wielu autorów i własne oparte na rozważaniach analitycznych i metodach Monte Carlo.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2008, 216
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of temperature on mechanical behavior of poly(lactic acid)
Autorzy:
Dusunceli, N.
Powiązania:
https://bibliotekanauki.pl/articles/284474.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
polymers
biodegradation
tests
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 112
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Untypical cases and incorrect results of vibration tests
Autorzy:
Wiśniewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/242412.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
vibration tests
vibration analysis
resonance tests
resonance analysis
modal analysis
Opis:
The vibration analysis is the study of the behaviour and dynamic properties of mechanical structures under actuation by harmonic vibration forces. The aim of resonance tests of the structures is the experimental delimitation of frequencies and the modes of resonance vibrations. vibration analysis, or more precisely experimental vibration analysis, is the field of measuring and analyzing the dynamic response of mechanical structures when excited by a mechanical input. The broadly applied method of research relies on the harmonic actuation of vibrations and the measurement of respective parameters. Examples would include measuring the vibration of an aircraft load bearing structure when it is attached to an electromagnetic force actuator. Current vibration testing systems are composed of actuators set with their control and powering circuits, the vibration measurement transducers (typically accelerometers), an analog-to-digital converter to digitize analog instrumentation signals) and a system host computer to analyze the data and view it. The result of researcher own accumulated experiences and those experiences knownfrom the literature create the possibility for design o f a stochastic frame model describing, what type of resonances are possible to expect in the given or other type of structure. The cases submitted below became perceived and tested in the course of research of several aircraft, glider and helicopter designs in the Resonance Tests Program of the Institute of Aviation
Źródło:
Journal of KONES; 2009, 16, 1; 591-597
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie najnowszych badań konserwatorskich w określeniu technologii i stanu zachowania obrazu Biała Dama, czyli portretu Teofili z Działyńskich 1º v. Szołdrskiej 2º v. Potulickiej z Muzeum w Kórniku
Autorzy:
Rogóż, Jarosław
Gansukh, Solongo
Cupa, Adam
Powiązania:
https://bibliotekanauki.pl/articles/28762725.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Biblioteka Kórnicka PAN
Tematy:
Biała Dama
badania nieinwazyjne
badania próbek
badania fizykochemiczne
White Lady
non-invasive tests
physicochemical tests
sample tests
Opis:
W artykule przedstawiono wyniki badań technologii i techniki wykonania XVIII-wiecznego obrazu będącego w zbiorach Zamku w Kórniku. Po raz pierwszy zbadano strukturę obrazu przy użyciu kombinacji technik nieinwazyjnych i mikroinwazyjnych. Zastosowano nieniszczące techniki obrazowania: rentgenografię (RTG), reflektografię w ultrafiolecie (RUV), fluorescencję wzbudzaną ultrafioletem (FUV), reflektografię w świetle widzialnym (VIS), reflektografię w podczerwieni (IR) oraz techniki obrazowania fałszywym kolorem w ultrafiolecie (UVFC) i podczerwieni (IRFC). Skład chemiczny warstw malarskich zbadano za pomocą metod mikrochemicznych oraz instrumentalnych: fluorescencji rentgenowskiej (XRF), spektroskopii w podczerwieni (FTIR), mikroskopii elektronowej (SEM-EDS) i chromatografii gazowej (GC). Celem tych badań było zidentyfikowanie pigmentów i spoiw użytych przez artystę oraz określenie stanu zachowania obiektu.
The article presents results of examinations of the technology and technique of the creation of an 18th-century painting kept in the collections of the Castle in Kórnik. The structure of the painting was examined for the very first time using a combination of non-invasive and micro-invasive techniques, including non-destructive imaging techniques such as roentgenography (X-ray), ultraviolet reflectography (UVR), ultraviolet fluorescence (UVF), visible reflectography (VIS), infrared reflectography (IR), as well as techniques of imaging using false colour: ultraviolet (UVFC) and infrared (IRFC). The chemical composition of the painting layers was checked with the help of microchemical and instrumental methods: X-ray fluorescence (XRF), infrared spectroscopy (FTIR), electronmicroscopy (SEM-EDS) and gas chromatography (GC). The tests were aimed at the identification of the pigments and binders used by the artist and determination of the state of preservation of the work.
Źródło:
Pamiętnik Biblioteki Kórnickiej; 2022, 39; 111-125
0551-3790
Pojawia się w:
Pamiętnik Biblioteki Kórnickiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Braking moment comparison and analysis for various brake designs using results from sample and full scale friction material tests
Autorzy:
Skorupka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/242444.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
motor vehicle
brake
brake design
brake tests
full scale tests
model tests
friction material
Opis:
Brake is one of the most important safety feature in every mechanical vehicle from bikes to airplanes. Brakes have to be designed in order to meet safety, reliability, efficiency and economical requirements. One has to remember that not only design of brake is important but also friction material used in its construction. Without proper materials, brakes are not able to generate proper braking moment. Braking moment is the most important parameter of brake from operation point of view. It is directly connected to braking distance as well with amount of force needed to achieve assumed braking parameters for the mechanical vehicle. Stability of braking moment is important in order to get optimized characteristics of the braking process itself. Most of the brake characteristics and efficiency calculations base on assumption that braking moment should be stable during braking process. During years of tests made on full scale brakes and friction material sample tests, author observed that real braking moment curve is not stable during braking process. This phenomenon is likely to affect braking efficiency and in result slightly change braking distance. In this paper author would like to address this issue by showing brake moment curves made for different brakes and friction materials. Tests, which were author’s base for paper contents, were made using full scale brake testing and friction material sample testing. All of the tests described in the paper were performed in Landing Gear Laboratory of Warsaw Institute of Aviation in which author works on daily basis
Źródło:
Journal of KONES; 2013, 20, 1; 303-308
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Remarks on Empirical Power of Tests for Pairs
Uwagi o empirycznej mocy testów dla par
Autorzy:
Domański, Czesław
Powiązania:
https://bibliotekanauki.pl/articles/905694.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
observations for pairs
nonparametric tests
power of tests
Monte Carlo simulations
Opis:
The paper deals with the tests for paired variables called also tests for pairs of variables. The observations are made of pairs of measurements. They can be correlated. It causes the necessity of applying another significance test of differences for example between means than in case of independent samples. We compare the power of nonparametric tests: sign test, Munzel and Wilcoxon tests with the Student’s test for pairs.
W artykule prezentowane są testy dla zmiennych połączonych, zwanych także testami dla par zmiennych. Obserwacje składają się z par pomiarów. Mogą być one skorelowane. Sytuacja ta sprawia, że należy zastosować inny test istotności różnic, np. pomiędzy średnimi aniżeli w przypadku prób niezależnych. Porównujemy moc testów nieparametrycznych: znaków, Wilcoxona i Munzela z testem t-Studenta dla par.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2006, 196
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identifying talented handball players – the possibilities of examining the players by means of speed-force and coordination tests
Autorzy:
Zubik, Mateusz
Spieszny, Michał
Sumara, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/1054683.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
coordination tests
handball
identifying the talented players
motor tests
somatic features
Opis:
The main aim of this thesis was to assess the usefulness of the chosen tests of motor skills (focused mainly on the work of the lower and upper limbs) and the computerized motor skills tests in identifying the talented handball players. To examine them, the players’ results from two junior teams were compared. The first test was performed before the players started high school, that is, at the age of sixteen. The results were compared with the sport level examined during the second test, performed when the players reached the senior age (nineteen years old). The Spearman’s rank correlation coefficient among the ranking results (sport level), somatic features and motor skills, was used in the analysis, with the level of statistical significance being p<0,05. Significant statistical correlations were discovered between the level of anaerobic force of the examined handball players when they are sixteen, and their sport level when they are nineteen years old. The significant statistical correlations may be one reason to use the tests of speed-force skills to identify the talented handball players described in this thesis. Among the coordination skills, only the multitasking ability proved to have significant statistical correlations with the players’ sport level.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2013, 4, 4; 53-62
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polymerization shrinkage of dental composites
Autorzy:
Pałka, K.
Zaszczyńska, A.
Kleczewska, J.
Powiązania:
https://bibliotekanauki.pl/articles/285764.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
dental composites
polymerization
tests
Źródło:
Engineering of Biomaterials; 2017, 20, no. 143 spec. iss.; 62
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Międzynarodowe testy języka angielskiego: japońskie paradoksy i kontrowersje
Autorzy:
Agnieszka, Gromkowska-Melosik,
Powiązania:
https://bibliotekanauki.pl/articles/892444.pdf
Data publikacji:
2019-04-29
Wydawca:
Uniwersytet Warszawski. Wydawnictwa Uniwersytetu Warszawskiego
Tematy:
tests
English
competencies
identity
Opis:
The aim of the article is to describe – on the example of teaching English – the reductionistic character of the testing phenomenon. Global international tests (TOEFL and TOEIC) provide excellent arguments to critics of the phenomenon of “testology”, related to reducing the school’s identity and student identity to results of test. An excellent example of this phenomenon is Japanese society. In Japan, where English is considered the cultural and professional capital of individuals, the paradoxes (and absurdities) of testing find their best exemplification. At the same time, the fact that English is completely different from Japanese results in contextualizing language tests in different, sometimes unexpected, cultural aspects of life. In addition, the controversy surrounding the testing of the English language proficiency in Japan is related to the discussion about cultural imperialism. All these issues will be analysed in the article, not only in the Japanese context but also in relation to whole “testing culture”.
Źródło:
Kwartalnik Pedagogiczny; 2019, 64(1(251)); 47-57
0023-5938
Pojawia się w:
Kwartalnik Pedagogiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selective F tests for sub-normal models
Autorzy:
Nunes, Célia
Mexia, João
Powiązania:
https://bibliotekanauki.pl/articles/729820.pdf
Data publikacji:
2003
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
ective F tests
sub-normal models
max-min tests
orderings
Opis:
F tests that are specially powerful for selected alternatives are built for sub-normal models. In these models the observation vector is the sum of a vector that stands for what is measured with a normal error vector, both vectors being independent. The results now presented generalize the treatment given by Dias (1994) for normal fixed-effects models, and consider the testing of hypothesis on the ordering of mean values and components.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2003, 23, 2; 167-174
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
F-tests for generalized linear hypotheses in subnormal models
Autorzy:
Mexia, Joao
Dias, Gerberto
Powiązania:
https://bibliotekanauki.pl/articles/729870.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
F-tests
subnormal models
mixed models
invariance
UMP tests
third type error
Opis:
When the measurement errors may be assumed to be normal and independent from what is measured a subnormal model may be used. We define a linear and generalized linear hypotheses for these models, and derive F-tests for them. These tests are shown to be UMP for linear hypotheses as well as strictly unbiased and strongly consistent for these hypotheses. It is also shown that the F-tests are invariant for regular transformations, possess structural stability and are almost strongly consistent for generalized linear hypothesis. An application to a mixed model studied by Michalskyi and Zmyślony is shown.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2001, 21, 1; 49-62
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exact similar tests for the root of a first-order aptoregresslve regression model
Dokładne podobne testy dla pierwiastka pierwszego rzędu autoregresyjnego modelu regresji
Autorzy:
Kiviet, Jan F
Phillips, Garry D. A
Powiązania:
https://bibliotekanauki.pl/articles/905019.pdf
Data publikacji:
1993
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
Autoregressive models
non-stationarity
unit roots
exact tests
similar tests
dynamic specification
Opis:
Opisano procedurę testu dla zbadania czy współczynnik zmiennej zależnej opóźnionej w autoregresyjnym modelu regresji wielokrotnej pierwszego rzędu równa się pewnej konkretnej wartości, np. zeru lub jedności lub innej dowolnej stabilnej lub niestabilnej wartości. Przy hipotezie zerowej estymator tego współczynnika ma rozkład jak rozkład ilorazu dwóch kwadratowych form w standardowych zmiennych normalnych, gdy prócz regreaorów egzogenlcznych, włóczono takie niektóre zbędne zmienne objaśniające. Rozkład związany z hipotezą zerową Jest wolny od .Jakichkolwiek kłopotliwych parametrów. Zatem estymatory te są łatwo policzalne i mogą być uiytc Jako statystyka testu; Jej błędy typu I mogą być dokładni« kontrolowane, podczas gdy teat ten jest podobny a takže niezmienniczy. Poszczególne testy pierwiastków jednostkowych stworzone przez Dickeya i Fullera wydają się być prostymi przykładami naszego testu dla bardzo specyficznych macierzy planu. Podane zostają rozszerzone tablice dokładnych wartości krytycznych dla tych i niektórych innych form. W końcu ilustrujemy przydatność naszej ogólnej procedury testu przy dynamicznej specyfikacji ekonometrycznych modeli szeregów czasowych.
A procedure is developed for testing whether or not the coefficient of the lagged dependent variable in a fir.t-order autoregressive multiple regression model equals a particular value, such as zero or unity or any other arbitrary stable or unstable value. Under the null hypothesis the estimate of this coefficient is found to be distributed as the ratio of two quadratic foras in standard normal variables, when it is obtained from a particular auxiliary regression model where in addition to the exogenous regressors also some redundant transformed regressors ara included. This null distribution is found to be independent of any nuisance parameters. So this estimate is easily calculated and it can directly be used as a test statistic} its type I error can be controled exactly, whereas this test is similar and also invariant. Particular unit root tests developed by Dickey and Fuller appear to be simple examples of our test for very specific regressor matrices. He provide extended tables of exact critical values for these and for some other forms. Finally we illustrate the usefulness of our general test procedure in the dynamic specification of econometric time series models.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 1993, 132
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Science and practice of core stability and strength testing
Autorzy:
Zemková, Erika
Powiązania:
https://bibliotekanauki.pl/articles/1923682.pdf
Data publikacji:
2018-09-19
Wydawca:
PPHU Projack Jacek Wąsik
Tematy:
core muscle tests
lifting task
muscle power
torsional tests
trunk rotations
Opis:
This study deals with a gap between science and practice in the testing of core stability and strength and presents our approach to solving this issue. Typical core stability tests require the subject to maintain a neutral spinal posture while under load in a quadrupedal or supine position and assess the endurance of global core muscles. However, most of these non-dynamometric tests have been developed for use in clinical and research settings. A suitable alternative represents torsional tests performed under stable or unstable conditions and instrumented tests in the form of trunk repositioning and load release tasks. Core strength is measured in terms of how much weight can be lifted, how many repetitions can be performed, or how long a neutral stable position can be maintained. In the laboratory, isometric and isokinetic dynamometers are frequently used. Isometric strength measurements are usually recommended as a standard for lifting tasks. However, such measurements underestimate the loads on the spine during dynamic movement. A deadlift to high pull exercise that involves working major muscle groups in the upper and lower body may best simulate the demands of jobs comprising of lifting tasks. Furthermore, isokinetic loading does not occur in daily human activities and is not specific to the requirements of sports. Given that rotational power is a better predictor of athlete performance, the test adapted from the wood chop exercise on a weight stack machine may provide conditions imposed by sports. One can also use a system that allows evaluation of muscle power during seated or standing trunk rotations with a barbell placed on the shoulders. These tests utilizing portable diagnostic systems may be implemented in functional diagnostics for athletes and sedentary or manual workers whose activities involve lifting tasks or trunk rotations under unloading or loading conditions; so complementing existing testing methods.
Źródło:
Physical Activity Review; 2018, 6; 181-193
2300-5076
Pojawia się w:
Physical Activity Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Próby konstruktorskie wiatrakowca I-28 budowanego w kategorii "specjalny"
Designer’s tests of an autogiro I-28 developed in category ”special”
Autorzy:
Delega, M.
Krzymień, W.
Powiązania:
https://bibliotekanauki.pl/articles/212978.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
wiatrakowiec
badania wytrzymałościowe
próby konstruktorskie
autogyro
mechanical tests
designer’s tests
Opis:
Wiatrakowiec I-28 został zaprojektowany i wykonany w ramach projektu „Technologia wdrożenia do praktyki gospodarczej nowego typu wiropłatowego statku powietrznego”. Jest to pierwszy wiatrakowiec zbudowany w Instytucie Lotnictwa i jako obiekt doświadczalny został zarejestrowany w kategorii „Specjalny”. Konstrukcja posiada wiele innowacyjnych rozwiązań i na każdym etapie prowadzone były próby weryfikujące przyjęte przez konstruktorów założenia. W artykule przedstawiono wybrane badania i testy, które zostały wykonane poza wymaganymi przez przepisy lotnicze ASTM, a których celem było zwiększenie bezpieczeństwa lotu oraz potwierdzenie założeń i wymagań konstruktorów.
Autogiro I-28 was designed and realized within the framework of the project "Implementation of technology in the practice of a new kind rotary-wing of the aircraft". It is the first autogiro constructed and tested in the Institute of Aviation and as an experimental object was registered in the category "Special". This construction has many innovative solutions and on each stage of development some tests were provided to verify the assumptions made by the constructors. In this paper some selected tests and investigations are presented, which were made beyond some tests required by the civil air regulations, and the goal of which was enhancing the safety of the flight and confirmation of the constructors’ assumptions and requirements.
Źródło:
Prace Instytutu Lotnictwa; 2014, 2 (235) June 2014; 38-48
0509-6669
2300-5408
Pojawia się w:
Prace Instytutu Lotnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania drogowe i symulacyjne przedłużonego zestawu pojazdów ciągnik siodłowy-naczepa
Road and virtual tests of elongated vehicle combination tractor and semi-trailer
Autorzy:
Cholewiński, S.
Łączyński, J.
Olejnik, K.
Powiązania:
https://bibliotekanauki.pl/articles/315397.pdf
Data publikacji:
2016
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
badania drogowe
badania symulacyjne
przedłużone naczepy
road tests
simulation tests
extended semi-trailers
Opis:
W artykule przedstawiono przebieg badań naczepy wydłużonej o 1,3 m w Polskich warunkach eksploatacyjnych i uzyskanie wiarygodnego materiału porównawczo-badawczego, mogącego stanowić podstawę do decyzji o ewentualnym wprowadzeniu tego typu przedłużonych naczep do normalnej eksploatacji. Badania te zostały przeprowadzone symulacyjnie i eksploatacyjnie w celu porównania wyników.
This paper presents the testing process of the extended semi-trailer by 1.3 m in the Polish operating conditions and obtaining a reliable material for comparison and research, which could provide a basis for decisions on the possible introduction of this type of extended semi-trailers into normal operation. These tests have been carried out by simulation and operationally in order to compare the results.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2016, 17, 12; 876-880
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wear in friction brakes Wear in friction brakes
Autorzy:
Skorupka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/243767.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
wear
wear testing
brakes
friction pair
friction material tests
full-scale brake tests
Opis:
Parameters of friction systems decline in time by the process of wear. In friction brakes, the wear phenomenon is much more visible than in other friction systems. Wear itself is on one hand not desirable because of need for brake system parts replacement but sometimes is needed due to regeneration of the friction area which is damaged for example by temperature or aggressive ambient conditions. Wear can be fatal or catastrophic for the friction brake, leading to heavy damage or even to permanent loss of braking capability during operation. As the brake is one of the crucial safety systems in both aviation and road vehicles, it is necessary to know if and how wear will be present in friction brake system before the brake is allowed to be installed in the vehicle, especially one that carries people. Wear can be estimated via numerical methods for well-known brakes (i.e. materials) or it has to be tested using laboratory methods in order to check and prove or deny initial design assumptions. In this paper, the author describes the phenomenon of friction brake wear and laboratory-testing methods of friction materials wear using brake model test stand for aviation brake friction materials certification testing located in Institute of Aviation Landing Gear Laboratory. Author also presents sample data from aviation brakes materials testing in order to show how wear can affect friction brake performance and durability.
Źródło:
Journal of KONES; 2016, 23, 2; 325-332
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The safety of motorcycle users
Autorzy:
Bańkowski, Antoni
Frej, Damian
Powiązania:
https://bibliotekanauki.pl/articles/24200874.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz. Przemysłowy Instytut Motoryzacji
Tematy:
motorcycles
crash tests
safety
Opis:
There are more and more motorcycles on the roads. This can be seen, for example, on the basis of statistical data from the Central Statistical Office, where newly registered two-wheelers are presented. Based on the data, it can be seen that there are more and more newly registered motorcycles every year and that there are many road accidents involving two-wheelers. According to data provided by the WHO, as many as 28% of fatalities in road accidents are motorcycle drivers [10]. The article below presents a review of the literature related to motorcycle crash tests and the dummies used for the tests. The work presents the most important standard that regulates how motorcycle crash tests are performed. The main purpose of the article is to draw attention to the problem of safety of motorcycle users. The text describes various crash tests of two-wheelers and stands used for testing motorcycles. The work presents a dummy specially designed for crash tests involving motorcycles. Differences between this dummy and other dummies used have also been described. The paper discusses the literature and describes research related to crash tests.
Źródło:
Archiwum Motoryzacji; 2023, 101, 3; 32--49
1234-754X
2084-476X
Pojawia się w:
Archiwum Motoryzacji
Dostawca treści:
Biblioteka Nauki
Artykuł

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