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1

Performance of map applications on mobile devices: case study

Król Karol, Halva Jozef, Pagáč Mokrá Alexandra

Geomatics, Landmanagement and Landscape

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2020

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no. 3

55--64

EN

Performance is one of the most important indicators of quality of software. It plays a significant role not only for business websites and apps, but in case of map components and applications, especially for mobile devices. The aim of the paper is to measure performance of map applications on mobile devices. The performance testing was run on a prototype of an interactive map component of the zoom-lens type using selected web applications. Speed Index (measurement unit) reached the value of 1601 milliseconds, and Performance Score obtained the highest possible value (100 units). A high value of Lighthouse Performance Score was also noted (98 units). Study showed that satisfying measurement results of indices in relation to the time of loading of the component in the browser window are associated with a small size of the component. In case of small components, which enhance the functionality of map websites and apps, it is recommended to compress all parts of the component, regardless of the results of the performance tests.

PL

Wydajność jest jednym z najważniejszych wyznaczników jakości oprogramowania. Wydajność ma istotne znaczenie nie tylko dla witryn i aplikacji biznesowych, ale także w przypadku komponentów i aplikacji mapowych, w szczególności na urządzeniach mobilnych. Celem pracy jest pomiar wydajności aplikacji mapowej na urządzeniach mobilnych. Testom wydajności poddano prototyp interaktywnego komponentu mapowego typu „zoom-lens”. Testy przeprowadzono przy pomocy wybranych aplikacji internetowych. Wskaźnik Speed Index (pomiar jednostkowy) osiągnął wartość 1601 milisekund, a wskaźnik Performance Score osiągną największą możliwą wartość (100 jednostek). Odnotowano także dużą wartość wskaźnika Lighthouse Performance Score (98 jednostek). Badania pokazały, że zadowalające wyniki pomiaru wskaźników związanych z czasem wczytywania komponentu w oknie przeglądarki wynikają z niewielkiego rozmiaru komponentu. W przypadku niewielkich komponentów, które rozszerzają funkcjonalność witryn i aplikacji mapowych wskazana jest kompresja wszystkich część składowych komponentu, niezależnie od wyników testów wydajności.

2

Literature survey of interleaved DC-DC step-down converters for proton exchange membrane electrolyzer applications

Guida Vittorio, Guilbert Damien, Douine Bruno

Transactions on Environment and Electrical Engineering

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2019

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Vol. 3, No. 1

33--43

EN

Recently, the use of electrolyzers for hydrogen production through water electrolysis is of great interest in the industrial field to replace current hydrogen production pathways based on fossil fuels (e.g. oil, coal). The electrolyzers must be supplied with a very low DC voltage in order to produce hydrogen from the deionized water. For this reason, DC-DC step-down converters are generally used. However, these topologies present several drawbacks from output current ripple and voltage gain point of view. In order to meet these expectations, interleaved DC-DC step-down converters are considered as promising and interesting candidates to supply proton exchange membrane (PEM) electrolyzers. Indeed, these converters offer some advantages including output current ripple reduction and reliability in case of power switch failures. In addition, over the last decade, many improvements have been brought to these topologies with the aim to enhance their conversion gain. Hence, the main goal of this paper is to carry out a thorough state-of-the-art of different interleaved step-down DC-DC topologies featuring a high voltage gain, needed for PEM electrolyzer applications.

3

Теплоснабжения на основе термотрансформированной энергии стабилизирующего охлаждения печи и переохлаждения теплоносителя низкопотенциальных источников

Petrash V.D., Geraskina E.A., Danicenko N.V., Chernysheva I.V.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2018

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Z. 24 (174)

280-284

RU

В статье представлены исследования совместной работы отопления и горячего водоснабжения. Установлено, что эффективность системы возрастает с увеличением расхода теплоносителя на горячее водоснабжение, а также при снижении температуры теплоносителя в системе отопления. Аналитическим способом установлено для системы с доохлаждением рациональное сочетание исходных и режимных условий, которое в системе анализируемой структуры обеспечивает оптималное значение коэффициента преобразования.

EN

The article presents a study of the joint work of heating and hot water. It has been established that the efficiency of the system increases with an increase in the coolant flow rate for hot water supply, as well as with a decrease in the coolant temperature in the heating system. Analytically, a rational combination of initial and regime conditions is established for a system with subcooling, which in the system of the analyzed structure provides the optimal value of the conversion coefficient.

4

Uwarunkowania pracy reaktorów katalitycznych instalowanych w układach wylotowych silników spalinowych

Żmudka Z., Postrzednik S.

Instal

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2015

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nr 2

29--35

PL

Analizowano główne problemy związane z eksploatacją elementów układu wylotowego na przykładzie reaktora katalitycznego. Istotne są pozytywne oraz negatywne aspekty instalowania tych urządzeń. W tym zakresie szczególną uwagę zwrócono na stopień konwersji substancji szkodliwych oraz opory przepływu, jakie stawia reaktor na drodze wypływu spalin z silnika. W ujęciu modelowym zagadnienia oporów przepływu spalin, reaktor katalityczny traktowano jako element oporów miejscowych lub liniowych układu wylotowego silnika. W pierwszym przypadku liczbę oporu miejscowego wyznacza się stosując model Darcy’ego. W drugim przypadku ujęcie zagadnienia oporów przepływu spalin przez katalizator polega na przyjęciu liniowego układu modelowego, z rozłożoną liniowo wzdłuż drogi przepływu spalin dyssypacją energii. Problematykę zilustrowano wynikami badań eksperymentalnych trójfunkcyjnego reaktora katalitycznego zainstalowanego w układzie wylotowym silnika ZI. Określono wzajemne zależności pomiędzy eksploatacyjnymi parametrami pracy silnika a warunkami przepływu spalin przez reaktor katalityczny.

EN

Principal problems connected with operation of exhaust system elements have been analysed on the basis of three-way catalytic reactor. There are positive and negative aspects of the reactor installing. Within this range conversion rate of harmful substances and resistance of exhaust gas flow through the catalytic reactor were investigated. In energy (negative) aspect, catalytic converter can be treated as local or linear resistance element of exhaust system. In the first model local resistance number of the reactor is calculated using Darcy model. In the second case, exhaust gas flow resistance through catalyst is treated as linear resistance with energy dissipation distributed linearly along way of exhaust gas flow. The problem has been illustrated by results of experimental researches of three-way catalytic converter installed in exhaust system of the spark ignition engine. Interdependences between operating parameters of engine work and conditions of exhaust gas flow through the catalyst are determined.

5

Flue gas desulfurization by mechanically and thermally activated sodium bicarbonate

Walawska B., Szymanek A., Pajdak A., Nowak M.

Polish Journal of Chemical Technology

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2014

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Vol. 16, nr 3

56--62

EN

This paper presents the results of study on structural parameters (particle size, surface area, pore volume) and the sorption ability of mechanically and thermally activated sodium bicarbonate. The sorption ability of the modified sorbent was evaluated by: partial and overall SO2 removal efficiency, conversion rate, normalized stoichiometric ratio (NSR). Sodium bicarbonate was mechanically activated by various grinding techniques, using three types of mills: fluid bed opposed jet mill, fine impact mill and electromagnetic mill, differing in grinding technology. Grounded sorbent was thermally activated, what caused a signifi cant development of surface area. During the studiem of SO2 sorption, a model gas with a temperature of 300°C, of composition: sulfur dioxide at a concentrationof 6292 mg/mn3 oxygen, carbon dioxide and nitrogen as a carrier gas, was used. The Best development of surface area and the highest SO2 removal efficiency was obtained for the sorbent treated by electromagnetic grinding, with simultaneous high conversion rate.

6

Sensitivity analysis of key customers and revenue-oriented admission control and scheduling algorithm

Suchacka G., Borzemski L.

Management and Production Engineering Review

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2013

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Vol. 4, No. 1

65--73

EN

The paper deals with the problem of Quality of Web Service (QoWS) in e-commerce Web servers, i.e. in retail Web stores. It concerns the admission control and scheduling algorithm for a Web server system, which aims at preventing the system from overload to provide high QoWS level and ultimately, to increase Web site's conversion rate, i.e. to turn more visitors into customers. The sensitivity of the algorithm to changes in its basic parameter values was analyzed by using a simulation-based approach. Special attention was paid to evaluation of the parameter impact on conventional and business-related system performance metrics.

7

Inverse aspects of the three-way catalytic converter operation in the spark ignition engine

Żmudka Z., Postrzednik S.

Journal of KONES

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2011

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Vol. 18, No. 2

509-516

EN

There are two sides of the catalyst operation: favourable and adverse. The positive side can be expressed by a conversion rate of harmful substances which is the principal parameter of catalyst work in respect of ecology. However, resistance of exhaust gas flow through the catalytic converter is also an essential problem. This is just the negative, adverse side of the converter operation. The catalytic converter can be treated as a local or linear resistance element of exhaust system. The first model, in which flow resistance generated by a catalyst is treated as local resistance, is more simplified. It is especially useful in case, when detailed constructional data of converter are unknown and the analysis of flow resistances in exhaust system is necessary. The basic measured quantity of flow resistance is pressure drop of exhaust gas within the catalyst. Next, on the basis of taken measurements also resistance number for the tested catalyst is calculated and analysed. Resistance number of the converter is calculated using Darcy model. In the second case, exhaust gas flow resistance through catalyst is treated as linear resistance with energy dissipation (linear frictional resistance) distributed linearly along way of exhaust gas flow. Friction number for the tested converter is calculated and analysed. The problem has been illustrated by the results of experimental researches of the three-way catalytic converter installed in the exhaust system of the spark ignition engine.

8

Comprehensive approach to the work of catalysts in engine exhaust systems

Żmudka Z., Postrzednik S., Ciesiołkiewicz A.

Journal of KONES

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2004

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Vol. 11, No. 3-4

368-375

EN

The use of a catalytic converter is aimed first of all at reduction of the incomplete combustion products emission. Conversion rate of harmful substances is the principal parameterr of catalyst work in respect of ecology. However, resistance of exhaust gas flow through the catalytic converter is also essential problem, apart from its chemical efficiency because fining the catalyst in exhaust system alters flow characteristic of this system significantly. Thus, there was general purpose of the carried out experiments - determination of interdependence between operating parameters of engine work and conditions of exhaust gas flow through the selected catalysts tested. Flow resistance generated by converter is considered as a local resistance. Resistance number of the calalyst was calculated using Darcy model. lnquiries into relationship between flow and structural parameters of the converters were also made. Comparison of flow resistances for the tested converters is presented.