Wyniki wyszukiwania - BazTech

1

Proces rozdrabniania w młynie kulowym opisany teorią momentów statystycznych

Olejnik Tomasz P.

Technologia i Jakość Wyrobów

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2021

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R. 66

148--158

PL

W artykule przedstawiono wyniki badań mających na celu eksperymentalną weryfikację modelu rozdrabniania w młynie kulowym w oparciu o teorię momentów statystycznych. Badania kruszenia materiałów skalnych o różnej twardości przeprowadzono w młynie laboratoryjnym o objętości 6 dm3 . Dla określonych odstępów czasu pobierano próbki surowca z młyna i wykonano analizy granulometryczne, określając udziały procentowe produktu. Mielono cztery rodzaje materiału skalnego: gabro, kwarcyt, sjenit i piaskowiec żelazisty. Obliczono wartości momentów zerowych, momentów centralnych oraz współczynniki spłaszczenia i asymetrii. Zbadano zależności między tymi wartościami w funkcji czasu mielenia.

EN

Results of investigations which aimed at experimental verification of the model of grinding in a ball mill based on the theory of moments are presented in the paper. Grinding tests for rock materials with different hardness were carried out in a laboratory mill 6 dm3 in volume. Particle size distribution of the material was determined in specified time intervals. Four types of rock material were milled: gabro, quartzite, syenite and ferruginous sandstone. The values of zero moments, central moments and coefficients of flattening and asymmetry were calculated. Relationships between these values as a function of milling time were examined.

2

Coefficient inequalities for a subclass of Bazilevič functions

Fitri Sa’adatul, Marjono, Thomas Derek K., Wibowo R. B. E.

Demonstratio Mathematica

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2020

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Vol. 53, nr 1

27--37

EN

Let f be analytic in D={z:|z| < 1} with f(z)=z+∑∞n=2anzn, and for α ≥ 0 and 0 < λ ≤ 1, let B1(α,λ) denote the subclass of Bazilevič functions satisfying (…) <λ for 0 < λ ≤ 1. We give sharp bounds for various coefficient problems when f ∈ B1(α,λ), thus extending recent work in the case λ = 1.

3

Resource Tuned Optimal Random Network Coding for Single Hop Multicast future 5G Networks

Dong Dhawa Sang, Pokhrel Yagnya Murti, Gachhadar Anand, Qamar Faizan, Amiri Iraj Sadegh, Maharjan Ram Krishna

International Journal of Electronics and Telecommunications

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2019

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Vol. 65, No. 3

463--469

EN

Optimal random network coding is reduced complexity in computation of coding coefficients, computation of encoded packets and coefficients are such that minimal transmission bandwidth is enough to transmit coding coefficient to the destinations and decoding process can be carried out as soon as encoded packets are started being received at the destination and decoding process has lower computational complexity. But in traditional random network coding, decoding process is possible only after receiving all encoded packets at receiving nodes. Optimal random network coding also reduces the cost of computation. In this research work, coding coefficient matrix size is determined by the size of layers which defines the number of symbols or packets being involved in coding process. Coding coefficient matrix elements are defined such that it has minimal operations of addition and multiplication during coding and decoding process reducing computational complexity by introducing sparseness in coding coefficients and partial decoding is also possible with the given coding coefficient matrix with systematic sparseness in coding coefficients resulting lower triangular coding coefficients matrix. For the optimal utility of computational resources, depending upon the computational resources unoccupied such as memory available resources budget tuned windowing size is used to define the size of the coefficient matrix.

4

Variability in and correlations among selected physical properties of European larch (Larix decidua Mill.) seeds

Kaliniewicz Z., Tylek P., Anders A., Markowski P., Rawa T.

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2014

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nr 17(2)

123--134

EN

Selected physical attributes of European larch seeds harvested from 2 seed plantations and 2 commercial seed stands in north-eastern Poland were determined. The physical properties of seeds were measured, and the results were used to calculate indicators of seed weight and the frictional and geometric properties of seeds. Physical attributes and indicators were compared by Student’s t-test for independent samples, analysis of variance, correlation analysis and linear regression analysis. The average values of physical properties and indicators were determined at: critical transport velocity - from 5.93 to 6.13 m • s-1, thickness - from 1.25 to 1.43 mm, width - from 2.29 to 2.71 mm, length - from 3.71 to 4.57 mm, angle of sliding friction - from 27.85 to 31.98o, weight - from 4.03 to 6.14 mg, coefficient of sliding friction - from 0.54 to 0.63, arithmetic mean diameter - from 2.42 to 2.90 mm, geometric mean diameter - from 2.20 to 2.60 mm, aspect ratio - from 59.60 to 62.38%, sphericity index - from 57.27 to 59.40%, specific weight - from 1.81 to 2.33 g • m-1, volume - from 4.60 to 7.59 mm3 and density - from 0.82 to 0.91 g • cm-3. The material harvested in seed plantations differed from seeds from commercial seed stands in all parameters, excluding critical transport velocity. Seed weight was most correlated with the remaining parameters. The highest value of the correlation coefficient and the equation with the highest value of the coefficient of determination were reported for the dependence between seed weight and seed length. Seed weight was also relatively highly correlated with seed width, therefore, the use of mesh screens with round openings and/or cylindrical grain graders is recommended in seed sorting processes.

5

Analiza porównawcza metod wyznaczania wskaźników emisji związków toksycznych w spalinach silników okrętowych

Kniaziewicz T.

Combustion Engines

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2013

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R. 52, nr 3

399--406

PL

Właściwości ekologiczne okrętowych silników napędu głównego ze względu na emisję związków szkodliwych, są silnie zależne od warunków i stanu ich pracy. Stan pracy silnika jest zdeterminowany nastawami silnika dokonywanymi przez operatora oraz momentem oporu zależnym od charakteru pracy wykonywanej przez okręt. Pracę silnika, a tym samym wartość emisji związków toksycznych w spalinach, charakteryzuje zatem koniunkcja zbiorów: warunków pracy, nastaw sterowania oraz wartości momentów obrotowych. W artykule przedstawiono analizę porównawczą metod wyznaczania wskaźników emisji związków szkodliwych w spalinach silników napędu głównego statków w oparciu o opracowany w Akademii Marynarki Wojennej w Gdyni model matematyczny, fiński model STEAM oraz badania i analizy przeprowadzone przez Lloyd Register of Shiping.

EN

Ecological characteristics of marine propulsion engines due to the emission of harmful compounds are strongly dependent on the work condition and external conditions. The work condition is determined by the engine settings made by the operator and the movement of resistance depended on the nature of the work performed by the ship. The engine, and thus the value of toxic compounds in the exhaust gases, thus characterized by the conjunction of work condition, control settings and torque. This paper presents a comparative analysis of methods for determining coefficients of toxic compounds emission in exhaust gases from marine engines based on the developed in the Polish Naval Academy in Gdynia mathematical model, the Finnish model STEAM, research and analysis conducted by Lloyd's Register of Shipping.

6

Efficient Algorithm of Affine form Searching for Weakly Specified Boolean Function

Porwik P.

Fundamenta Informaticae

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2007

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Vol. 77, nr 3

277-291

EN

This paper presents the spectral method of recognition of an incompletely defined Boolean function. The main goal of analysis is fast estimation whether a given single output function can be extended to affine form. Furthermore, a simple extension algorithm is proposed for functions, for which the affine form is reachable. The algorithm is compared with other methods. Theoretical and experimental results demonstrate the efficiency of the presented approach.

7

Asymptotic behavior of solutions of impulsive differential equations with positive and negative coefficients

Wei G., Shen J.

Fasciculi Mathematici

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2005

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Nr 36

109-119

EN

This paper is concerned with the impulsive delay differential equations with positive and negative coefficients Sufficient conditions are obtained for every solution of the above equation tends to a constant as t —> &infin. KEY WORDS: asymptotic behavior, Liapunov functional, delay differential equation, impulse, coefficients.

8

Wyznaczanie średnich współczynników wnikania ciepła zmodyfikowaną i uogólnioną metodą Wilsona

Lechowska A., Nowarski A.

Czasopismo Techniczne. Budownictwo

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1998

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R. 95, z. 5-B

81--94

EN

The paper presents the modified and generalized Wilson method based on the classical modified Wilson technique. The modified and generalized methods are used to estimate theaverage heat transfer coefficients of the heat exchangers from test data. Althoughthe average hest transfer coefficient can be calculated by the integration of the local heat transfer coefficients, this approach is not convenient for many systems and configurationsbecause of the difficulties connected with measurements of local temperatures. In the case of complicated tube configurations, the Wilson method proves to be useful for obtaining average heat transfer coefficients. This method allows one to estimate individual resistances from the resistance. It should be mentioned that, as presented in the paper, the modified Wilson method has some limitations which restrict the range of its applications. Because the generalized Wilson method does not have such limitations it is more suitable for testing the heat exchangers data.