Wyniki wyszukiwania - Biblioteka Nauki

1

An experimental analysis of the flow structure in various configurations of a circular-planar SOFC fuel channel

100%

Nowak R. , Szmyd J. S.

Journal of Theoretical and Applied Mechanics

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2011

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tom Vol. 49 nr 2

541-564

EN

In the presented paper, the authors focus on the analysis of flow structure in various configurations of a circular-planar SOFC fuel channel. The research was carried out on the premise that a proper channel design would help minimize the thermal stress in the cell, which is affected by the heat generated and consumed by the reforming, water gas-shift and hydrogen consumption reactions. For the measurement process, PIV method was used to calculate the velocity fields, and an extensive error analysis was done to evaluate the accuracy of the calculated velocities.

PL

W zaprezentowanym artykule, tematem realizowanych badań jest analiza eksperymentalna struktury przepływu gazu w trzech modelach kanałów transportowych ogniwa paliwowego typu SOFC (Solid Oxide Fuel Cell). Celem badań było zaproponowanie geometrii kanału, która pozwoliłaby utrzymać jednorodny rozkład pola prędkości na powierzchniach elektrod w rzeczywistych warunkach pracy ogniwa. Dobór odpowiedniej geometrii kanałów transportowych jest istotny z punktu widzenia wydajności oraz bezpieczeństwa pracy ogniwa, ponieważ bezpośrednio wpływa na wydajność reakcji elektrochemicznych zachodzących w ogniwie oraz na rozkład temperatury w jego wnętrzu, uwarunkowany silnie egzotermicznymi reakcjami elektrodowymi oraz w przypadku wykorzystania paliwa węglowodorowego dodatkową, endotermiczną reakcją reformingu i egzotermiczną reakcją tlenku węgla z parą wodną. Na potrzeby eksperymentu zaprojektowano oraz wykonano z pleksi trzy przykładowe geometrie kanałów przepływowych. Badania eksperymentalne przeprowadzono w temperaturze pokojowej. Gazem wykorzystanym w badaniach było powietrze. Bazując na teorii podobieństwa ustalono wartości liczby Reynoldsa na poziomie odpowiadającym wielkościomliteraturowym, dzięki czemu otrzymane wyniki można traktować jako wiarygodne i oddające charakter przepływu paliwa w rzeczywistym ogniwie paliwowym. Profile prędkości wyznaczono wykorzystując bezinwazyjną metodę Particle Image Velocimetry. Ponadto, na podstawie analizy błędów określono zestaw parametrów obliczeniowych, dla których wyznaczone pole wektorowe charakteryzowało się największą dokładnością.

2

A skew ray tracing approach for error analysis of a light ray path for optical systems with asymmetrical optical axes

100%

Liao T. T. , Kung C. , Chen C. T.

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tom Vol. 45, nr 2

249--261

EN

This study applies a skew ray tracing approach based on a 4×4 homogeneous coordinate transformation matrix and Snell’s law to analyze the errors of a ray light path as it passes through a series of optical elements in an asymmetrical optical system. The proposed error analysis methodology considers two principal sources of a light path error, namely: i) the translational errors and the rotational errors which determine the deviation of the light path at each boundary surface, and ii) the differential changes induced in the incident point position and unit directional vector of the refracted/reflected ray as a result of differential changes in the position and unit directional vector of the light source. The validity of the proposed methodology is verified by analyzing the effects of optical errors in a corner cube.

3

The decision-feedback equalizer optimization for Gaussian noise

100%

Grzybowski A. , Kisilewicz J. W.

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2014

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tom Vol. 8, nr 4

5-12

EN

The new method of decision-feedback parameters optimization for intersymbol interference equalizers is described in this paper. The error extension phenomena is well known and investigated in the decision feedback equalizers in data transmission. The existing coefficient in decision feedback depends on the receive decision risk qualification. There is proved the bit error probability can be decreased by this method for any channel with single interference sample and small Gaussian noise. The experimental results are presented for chosen type channels. The dependences of optimal feedback parameters on channel interference sample and on noise power are presented too.

4

Transcription of foreign personal names in the written works of learners of Latvian as a foreign language

100%

Kļavinska A.

Journal of Education Culture and Society

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2021

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tom 12

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nr 2

469-481

EN

Aim. The aim of this study is to analyse how personal names are transcribed in the written works of Latvian as foreign language learners, as well as the most typical mistakes when transcribing personal names in other languages, the attitude of students towards the Latvianisation of their personal names, and the experience of Latvian language teachers in teaching the principles of transcribing personal names. Methods. The study uses the corpus analysis method, as well as a survey of students and survey of teachers who teach Latvian as a foreign language. The article includes error analysis of the personal name transcription established in the corpus and the analysis of the survey results. Results and conclusion. It was found out that students mostly know how to transcribe their names in Latvian; less frequently do they know how their surname should be transcribed. Their attitude towards Latvianisation of personal names is various: positive, negative or neutral. Latvian as a foreign language teachers emphasize the principle of transcription of foreign personal names and the need to provide its justification in the study process. It was concluded that further Latvian language acquisition process needs to be focused more on the problems with transcription of foreign personal names. Originality. This study highlights the aspect which is little researched in the applied linguistics – the issued linked to transcription of foreign personal names in the process of learning the Latvian language. The novelty is related to the use of a new resource (error-tagged learner corpus) data.

5

Uncertainty analysis of the kinetic model of natural gas combustion in IC Engine

100%

Mansha M. , Naqvi J.

Polish Journal of Chemical Technology

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2012

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tom 14

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nr 1

1-4

EN

The purpose of this analysis is to determine the uncertainties originating due to the kinetic parameters of the rate of a reaction proposed kinetic model. A kinetic model consisting of 208 reaction steps and 73 species was adopted for analysis. In the required uncertainty analysis, the accuracy of approximate models, generated by the Chemkin 4.1.1 for pollutant species, is determined. The reactions which contribute the uncertainty in the output concentrations of the pollutnats species formed in the combustion chamber were identified. The percentage contribution to the uncertainty in the output concentrations of pollutants were also determined.

6

Data correction method of the persistent scatterer interferometric synthetic aperture radar technique in landslide surface monitoring

100%

Xie M.-E. , Lv F.-X. , Wang L.-W.

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tom Vol. 26

91--109

EN

Landslides generally cause more damage than first predicted. Currently, many methods are available for monitoring landslides occurrence. Conventional methods are mainly based on single-point monitoring, which omits the aspect of variation in large-scale landslides. Due to the development of radar satellites, the differential interferometric synthetic aperture radar technique has been widely used for landslide monitoring. In this study, an experimental region in the Wudongde Hydropower Station reservoir area was studied using archived spaceborne synthetic aperture radar (SAR) data collected over many years. As the permanent scatterer interferometric SAR (PS-InSAR) technique is an advanced technology, it could be suitably used to overcome the time discontinuity in long time series. However, the accuracy of date processing obtained using the PS-InSAR technique is lower than that obtained using the single-point monitoring method. The monitoring results of the PS-InSAR technique only demonstrate the moving trend of landslides and do not present the actual displacement. The Advanced Land Observation Satellite and a high-precision total station were used for long-term landslide monitoring of the Jinpingzi landslide at the Wudongde Hydropower Station reservoir area. Based on a relationship analysis between the data obtained using the PS-InSAR technique and the total station, a revised method was proposed to reduce the errors in the PS-InSAR monitoring results. The method can not only enhance the monitoring precision of the PS-InSAR technology but also achieve long-term monitoring of landslide displacement from a bird's-eye view.

7

Skew ray tracing and error analysis of optical elements with ellipsoid boundary surfaces

100%

Liao T. T.

Optica Applicata

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2008

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tom Vol. 38, nr 4

677-692

EN

Utilizing a ray tracing approach based upon Snell's optical laws and a 4×4 homogeneous coordinate transformation matrix, this study conducts a systematic analysis of the errors induced in the paths of skew rays as they pass through an optical element with an ellipsoid boundary surface. The error analysis performed in this study considers two principal sources of light path error, namely (1) translational and rotational errors of the boundary surfaces, and (2) differential changes induced in the position of the incident ray on the boundary surface and the unit directional vector of the refracted/reflected ray as a result of changes in the position and unit directional vector of the light source. The validity of the proposed methodology is demonstrated by analyzing an optical element with an arbitrary ellipsoid boundary surface.

8

Correction Techniques Preferred by Students During the Process of Learning a Foreign Language

100%

Bargiel-Matusiewicz K. , Bargiel-Firlit A.

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tom 13

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nr 1

39-52

EN

Mistakes can be seen as an integral and natural part of learning. This is true of the development of a child's first language as well as of second language learning by children and adults. Learning never proceeds without making errors. They appear naturally in linguistic development. The main aim of the research is to find out if and how the learners appreciate error correction. Besides, its goal is to provide qualitative data concerning learners' opinions, as well as bring some comments on errors in their own experience. The research results clearly indicate that students generally believe that making errors is one of the things they do while learning a foreign language. They agree that they can learn a lot from their mistakes. Almost 40% of the research subjects think that error correction is absolutely necessary, and a half of them see correction as very helpful. They value correction as a means of improvement. Most learners are not afraid of errors and treat them as something natural. However, almost half of the research subjects associate making a mistake with the feeling of guilt. They use an avoidance technique in order not to be laughed at when they make a mistake. Thus, errors should not be approached with hostility. It is better to view errors as the sign of a learner's progress rather than a sign of lack of knowledge.

9

Testing and Assessing English Word-Formation

88%

Stopar A.

Romanian Journal of English Studies

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2014

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tom 11

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nr 1

290-297

EN

The paper discusses the testing/assessment of word-formation skills in thresholdlevel (B1) learners. To determine the suitability and use of productive gap-fill exercises at this level, an example of a word-formation exercise is addressed from the following perspectives: word frequency (corpus data), morphological complexity (morpheme types and wordformation processes), syntactic environments (typical sentence and/or phrase patterns), analysis of statistical data (facility values) and test-takers’ errors. The text also addresses some implications of the findings for the instruction of lexis.

10

La competencia intercultural y el error pragmático

88%

Tatoj C.

Studia Romanica Posnaniensia

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2021

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tom 48

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nr 2

45-54

EN

This paper discusses two topics which are very popular nowadays among the academics dealing with foreign language teaching, namely: intercultural competence and pragmatic error. The author notes the fact that those two notions appear separately, because the starting points for discussing them are usually different fields of science. The aim of the paper is to demonstrate that on one hand the two notions need to be treated uniformly, and on the other, that the pragmatic error should be included in error classifications which are references for both the authors of handbooks as well as people educating future teachers. For that purpose, the author defines intercultural competence, presents various approaches to error and its classification in teaching, and then explains what pragmatic error is and describes its linguistic characteristics.

11

Error analysis and language comparison as teaching strategies for German as a foreign language in a South African context

88%

Anne Baker A.

Problemy Wczesnej Edukacji

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2017

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tom 13

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nr 2(37)

103-110

EN

Since 2015 there has been increased protest action by students at South African universities. One of the issues is decolonizing the curriculum. Academics have been re-thinking the curricula of various academic offerings. Recognizing the African heritage of students studying German could be in the form of comparing the first language (L1) of black African learners with German in order to facilitate learning the target language (TL). Specific examples of similarities and differences between German and Zulu are addressed in this article.

12

Identyfikacja i klasyfikacja błędów językowych na lektoracie języka niemieckiego

88%

Kawka J.

Forum Filologiczne Ateneum

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2018

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tom 6

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nr 1

159-169

EN

Knowledge of foreign languages constitutes one of the key competencies amongst graduates of the Bachelor of Economics. In the era of globalisation, the importance of a high level of proficiency in foreign languages has become self-evident. The empirical part of this article is devoted to the analysis of the most common language mistakes committed by first-year students of the B1 group of Marketing and Management at the University of Economics in Krakow. A portion of the final exams submitted by a group of 13 students has been analyzed. The study focuses on the identification and classification of errors and presents the frequency distribution, as percentages, of errors in individual categories. The author's intention is not to indicate the causes of errors and their assessment, but to present the problems faced by students of the Bachelor of Economics, who learn ‘business language’, which a specialism within the German language studies. The results of the study might act as a starting point for the development of appropriate educational materials to support the process of teaching a wide variety of German language courses.

13

Solving systems of fractional two-dimensional nonlinear partial Volterra integral equations by using Haar wavelets

88%

Khajehnasiri A. A. , Ezzati R. , Kermani M.

Journal of Applied Analysis

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2021

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tom Vol. 27, nr 2

239--257

EN

The main aim of this paper is to use the operational matrices of fractional integration of Haar wavelets to find the numerical solution for a nonlinear system of two-dimensional fractional partial Volterra integral equations. To do this, first we present the operational matrices of fractional integration of Haar wavelets. Then we apply these matrices to solve systems of two-dimensional fractional partial Volterra integral equations (2DFPVIE). Also, we present the error analysis and convergence as well. At the end, some numerical examples are presented to demonstrate the efficiency and accuracy of the proposed method.

14

On the improvement of calibration accuracy of parallel robots – modeling and optimization

88%

Bentaleb T. , Iqbal J.

Journal of Theoretical and Applied Mechanics

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2020

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tom Vol. 58 nr 1

261--272

EN

This paper proposes kinematic based calibration methods for Delta parallel robots. The boundary of the robot workspace is computed using a forward kinematic model. Influence of errors in kinematic parameters on the workspace boundaries is investigated. The novelty of the proposed approach lies in Jacobian-based computation of kinematic models. Also, the present work extends and applies the existing calibration methods traditionally meant for serial robots on the Delta robot. These methods include the forward method and the inverse method. Simulation results confirm the efficacy of the proposed calibration strategies.

15

Frequency analysis of preconditioned waveform relaxation iterations

88%

Augustynowicz A. , Jackiewicz Z.

Applicationes Mathematicae

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1999

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tom 26

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nr 2

229-242

EN

The error analysis of preconditioned waveform relaxation iterations for differential systems is presented. This analysis extends and refines previous results by Burrage, Jackiewicz, Nørsett and Renaut by incorporating all terms in the expansion of the error of waveform relaxation iterations in the Laplace transform domain. Lower bounds for the size of the window of rapid convergence are also obtained. The theory is illustrated for waveform relaxation methods applied to differential systems resulting from semi-discretization of the heat equation in one and two dimensions. This theory and some heuristic arguments predict that preconditioning is most effective for the first few iterations.

16

Bliskość pomiędzy językami słowiańskimi a integracja uchodźców z Ukrainy w Polsce

75%

Saturno J.

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2023

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tom 30

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nr 1

153-176

EN

The paper is devoted to the specificities of the acquisition of L2 Polish by speakers of a closely related language (East Slavic one), with specific regard to the language-teaching consequences of said proximity. After an introduction to the current historical and sociolinguistic context of the East Slavic immigration to Poland, the data presents the concept of “intercomprehension”. Its impact on the acquisition of L2 Polish is illustrated by the use of empirical data collected by the author’s research team. The article is concluded by means of a reflection on the value of multilingualism in the school system and the skills required of Polish teachers in the present historical contingencies. It is argued in particular that due to the great number of Ukrainian pupils enrolled in the Polish schools, it is advisable for Polish school teachers to have at least some knowledge of the native languages of these pupils, with the primary goal of improving communication in stressful situations and adequately interpret and correct their errors in L2 Polish.

17

Analiza błędu rozwiązania numerycznego problemu brzegowo-początkowego w nieskończonym układzie cylindrycznym

75%

Ziemba A.

Rudy i Metale Nieżelazne

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2007

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tom R. 52, nr 9

549-554

PL

Jednym z podstawowych problemów numerycznego rozwiązywania modelu matematycznego procesu fizycznego jest określenie dokładności otrzymanych wyników. Schematy numeryczne, bezwarunkowo stabilne i zbieżne w przestrzeni liczb rzeczywistych, w zbiorze liczb zmiennoprzecinkowych mogą okazać się niestabilne i niezbieżne. W skrajnych przypadkach obliczenia mogą stać się niewykonalne lub prowadzić do rozwiązania wirtualnego problemu numerycznego. Analiza błędu rozwiązania numerycznego może pozwolić na otrzymywanie wyników o kontrolowanej dokładności i określanie optymalnych wartości parametrów numerycznych schematu i modelu. W artykule zaproponowano przykład analizy błędu rozwiązania numerycznego i wykazano jej przydatność w rozwiązywaniu problemu brzegowo-początkowego w nieskończonym układzie cylindrycznym z wewnętrznym źródłem ciepła, mającego zastosowanie m.in. przy obliczeniach wymienników ciepła, wymiany ciepła w prętach i rurach w procesach przeróbki plastycznej, wymiany ciepła przy ciągłym odlewie metali i stopów. Wykazano zależność pomiędzy parametrami schematu numerycznego, zapewniającą otrzymanie poprawnego rozwiązania w zbiorze liczb zmiennoprzecinkowych.

EN

One of the fundamental problems in numerical solution of a mathematical model of physical process is determination of the results accuracy. The unconditional convergence and stability of numerical schemes are usually confirmed in real number system, which is an abstract mathematical concept. Computations are realized in the floating-point numbers system, which is imperfect discrete representation of the real number system in computer’s memory. The basic properties of real numbers do not suit sufficiently to the basic properties of floating-point numbers, what could be a result of the computational errors, causing the improper solution. In extreme situation the choice of wrong computational parameters cannot give the solution or leads to the solution of virtual numerical problem. Solution obtained in such a way could still be taken as a proper one, because sometimes it is difficult to distinguish difference between the real and virtual solutions. The error analysis, a set of numerical solution methods, can give the results of controlled accuracy and can help to determine the optimal values of parameters of numerical schema and mathematical model. Error analysis is too difficult to be automated, but it is possible with numerical experiment. In this paper the error analysis is proposed and its usefulness is indicated for the initial-boundary problem of heat transfer, with inner heat source, in cylindrical coordinates system. Such system can be found, inter alia, in the analysis of heat exchangers, heat transfer in rods and tubes in the plastic deforming processes, heat transfer during the process of continuous casting of metals and alloys. The importance of the error analysis is emphasized. Relation between parameters of numerical schema, which ensures proper solution in floating-point numbers system, is stated.

18

Invented spelling – a window on early literacy

75%

Awramiuk E.

Edukacja

|

2014

|

nr 5(130)

112–123

EN

A wide spectrum of research on preschool spelling development in different languages is presented. In Poland, children at kindergarten are usually at a stage of pre-literacy. Invented spelling means the writing produced by young children (aged 3–7) before they are formally taught reading and writing or are at the beginning of the learning process. Their writing is more spontaneous than learnt. The paper describes an investigation of the development of early literacy and factors influencing it, such as knowledge about orthography (spelling), early morphological awareness or teaching methods. Children’s early writing provides a window on their conceptualisation of the written language, illustrating the process of developing language awareness and spelling skills. Invented spelling, together with phonological abilities and letter knowledge is considered to be a strong predictor for later literacy skills.

19

Error Analysis and Antenna Array Placement Optimization of Localization System for Partial Discharge in Substation

75%

He J. , Li M. , Chen G. , Wang Z.

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2014

|

tom R. 90, nr 7

104--107

EN

The measurement and diagnosis of partial discharge (PD) is accepted as one of the most valuable means for assessing the quality of high voltage (HV) power apparatus and its running status. However, the current partial discharge monitoring mainly based on equipment, which needs multi-process test equipment, high cost, and large maintenance engineering. This paper introduced the use of four antennas array to receive ultra-high frequency (UHF) signal, and define 3-D coordinate system, then located PD source in the field of the substation. Furthermore, this paper discussed the principles of the location algorithm based on time difference, analyzed the origin of its location error, then the connection of location error and the placement of antenna array and the error of time difference has been discussed theoretically. Finally, this paper provided the optimal placement of the radio frequency antenna array.

PL

W artykule opisano czteroantenowy odbiornik sygnału UHF w zastosowaniu do analizy źródła wyładowania niezupełnego. Analizowano błąd określenia pozycji źródła w zależności od rozłożenia systemu anten.

20

Wybrane zagadnienia analizy właściwości dynamicznych akcelerometrów w oparciu o rachunek różniczkowo-całkowy niecałkowitych rzędów

75%

Luft M. , Pietruszczak D. , Szychta E. , Szychta L.

|

2015

|

tom R. 22, nr 12

947--952, CD

PL

W artykule przedstawiono badania symulacyjne i laboratoryjne akcelerometru zamodelowanego klasyczną analizą matematyczną oraz wykorzystując rachunek różniczkowo-całkowy niecałkowitych rzędów. Dokonano analizy błędów modeli przetwornika. Wskazano na zalety stosowania rachunku ułamkowego do opisu dynamiki akcelerometrów. Badania symulacyjne wykonano w środowisku programistycznym MATLAB&Simulink.

EN

The paper presents simulation and laboratory stud-ies of measuring transducers (accelerometers) which were modelled in the classical differential equations as well as fractional calculus. Measurement errors are examined and a comparison to classical and fractional models in terms of dynamic properties is made. The advantages of fractional calculus in modelling dynamic elements are also indicated. Tests are executed in the MATLAB&Simulink programme.