Wyniki wyszukiwania - BazTech

1

Changes in the perception of telematics technology by road transport companies: an empirical analysis in 2020-21

Zalewski Wojciech, Osińska Magdalena, Żurek Mirosława

Transport Problems

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2023

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T. 18, z. 1

5--17

EN

We present a novel study concerning the attitudes of road transport enterprises towards a broad application of telematics in operational management in road transportation. The study aims to assess telematics application in road transport and its changes over time while showing the factors most likely to determine the systems’ use. Unobserved categories defined in the technology acceptance model (TAM) are adjusted to measure perceived usefulness, perceived ease of use, and attitudes toward using telematics systems by road transport managers. The study is based on 323 transport enterprises analyzed in two waves in 2020 and 2021. The use of two different time points is motivated by an observed increase in the digitalization of transport documents caused by the COVID-19 pandemic. The empirical findings support the TAM’s usefulness in evaluating IT in transport business management. The findings also reveal that the significantly increased telematics use in 2020 was observed while it was endured. The results are checked for robustness and used for simulations. The study compares managers’ behaviors over time and simulates the effect of individual (observed) variables on unobserved TAM categories.

2

Do telematics technologies help to manage road transport enterprises? Evidence from SME in Poland

Zalewski Wojciech, Osińska Magdalena, Żurek Mirosława

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

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2022

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z. 157

723--740

EN

Purpose: This study evaluates the acceptance of GPS/GPRS-based telematics technology in freight road transport companies registered in Poland. Design/methodology/approach: The evaluation is based on a survey of 500 representative road transport companies carried out in 2020. The Technology Acceptance Model was estimated, and its results were checked for robustness. The scope of the information collected in telematics systems is defined in terms of its perceived utility and perceived ease of use at the operational management level. The latent factors affecting technology use are defined and implemented. Findings: Most respondents (80%) claimed that telematics systems had a considerable influence on the effectiveness and efficiency of the whole company's operation. It contributed to a higher number of orders executed per time unit, more effective use of the driver's working time, and increased the entrepreneurs' trust in the company. The companies employing more workers recognize the higher usefulness of telematics systems and are motivated to use the technology more widely than smaller enterprises. TAMs estimated separately for small and medium-sized enterprises did not significantly differ among the parameter estimates. Research limitations/implications: The Technology Acceptance Model is a useful analytical tool for evaluating telematics technology acceptance by the road transport sector. The study is based on a random sample of enterprises observed once in 2020. It is recommended to monitor them in two or three waves to compare the dynamics of the telematics usage process. It is planned to continue the study in that direction. Practical implications: The outcomes are valuable in practice twofold. Firstly, the extension of telematics systems use is interesting for final users, i.e., road transport companies that will find scope for their application. Secondly, the results are helpful for system providers who get knowledge on telematics perception from enterprise management. Originality/value: Although widely applied to other IT systems, the TAM model has not been used to evaluate the use of telematics in road transport companies. The paper justifies TAM's categories at the operational management level in road transport enterprises, contributing to understanding managers' behavioral aspects of decision-making.

3

Covid-19 pandemic as a factor increasing truck drivers’ stress

Zalewski Wojciech, Osińska Magdalena, Chylewska-Barakat Lidia

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

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2022

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z. 160

685--702

EN

Purpose: The questionnaire-based study investigated whether the COVID-19 pandemic increased stress in busy truck drivers' jobs. Design/methodology/approach: The sample of 239 drivers was examined in March-August, 2021. Findings: The study revealed that most drivers were resilient to COVID-19-related stressors. Some stressors, such as age, seniority, recovering from COVID-19, and worsening family financial conditions, were found to have more impact on some respondents than others. Age and seniority were related to anxiety about increased occupational activities. Those whose economic conditions worsened were afraid of job loss. People who recovered from COVID-19 felt overworked more often than others and tended to be scared of safety on the road and being alone in the truck. They more often required psychological support. Research limitations/implications: The study is based on a sample of drivers observed conveniently in 2021. Monitoring them in two or three waves is recommended to compare the impact of other processes that could affect responses. Practical implications: The outcomes are valuable in practice twofold. Firstly, the knowledge is acquired directly from the drivers who proved to be pretty resilient to COVID-related issues; however, some were more sensitive than others. That means the drivers as an occupational group cannot be considered uniform. Some needed psychological support, and such cases should be identified at the enterprise level. Secondly, the results show that COVID-related stressors with other accompanying issues increase the impact on drivers’ health. Originality/value: The empirical results revealed the most significant stressors. They were justified by using several stress definitions and psychological theories, particularly the Conservation of Resources Theory. They can be considered in the drivers' management process.

4

Obliczenia projektowe gruntowych wymienników ciepła pomp ciepła

Zalewski Wojciech

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2019

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T. 50, nr 1

16--21

PL

Gruntowy wymiennik ciepła stanowi istotny element pompy ciepła, decydujący o poprawności działania całego urządzenia. Jego doboru powinno dokonywać się na podstawie wyników przeprowadzonych obliczeń projektowych, uwzględniających specyfikę procesu wymiany ciepła w gruncie. Wśród stosowanych metod obliczeniowych wymienników gruntowych wyróżnić można dwie: metodę Bosego i in. oraz metodę ASHRAE. Celem pracy jest przedstawienie algorytmów obliczeniowych pionowych wymienników gruntowych, przeprowadzenie przykładowych obliczeń projektowych polegających na wyznaczeniu głębokości odwiertów (długości sond) i porównanie wyników obliczeń otrzymanych zastosowanymi algorytmami. W obliczeniach wykorzystano dwie metody oparte na modelu Bosego i in. oraz na modelu ASHRAE, odnoszące się do wymienników typu pojedyncza U-rura dla jednej, trzech i sześciu sond w pętli. Otrzymane za pomocą obu metod wyniki obliczeń długości sond (głębokości odwiertów) nie różnią się zasadniczo między sobą. Większe głębokości odwiertów, a więc mniejsze gęstości strumienia pozyskiwanego z gruntu ciepła otrzymano stosując metodę ASHRAE. Różnice procentowe nie przekraczają 20%. Ze względu na większą uniwersalność modelu Bosego i in. zaleca się stosowanie w praktyce metody obliczeniowej opartej na tym modelu.

EN

The ground heat exchanger is an essential element of the heat pump that determines the correct operation of the entire device. Its selection should be made on the basis of the results of the design calculations that accommodate specificity of the heat exchange process in the ground. Among others, the Bose et al. method and the ASHRAE method are applied to calculate the ground exchangers. The aim of the paper to present the computational algorithms for vertical ground exchanger, run the examples of design calculations that consist of determining the depth of boreholes (the length of tubes) and compare the calculation results obtained with the applied algorithms. Two methods based on the Bose et al. model and the ASHRAE model were used during the calculations. They pertain to the single U-tube type exchanger for either one, three or six tubes in a loop. The calculation results of the length of tubes (the depth of boreholes) obtained with both methods are not fundamentally different. Greater depths of boreholes, and thus lower heat flow rate intensity was achieved using the ASHRAE method. The percentage differences do not exceed 20%. Due to the greater universality of the Bose et al. model, it is recommended to use the calculation method based on this model in practice.

5

Obliczenia cieplne parowaczy typu "sopel lodu"

Zalewski Wojciech

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2019

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T. 50, nr 2

62--66

PL

Powietrze atmosferyczne jest powszechnie dostępnym źródłem ciepła niskotemperaturowego dla pomp ciepła, którego wykorzystywanie nie powoduje żadnych zakłóceń równowagi cieplnej otoczenia. Do jego zalet zalicza się również stosunkowo niskie koszty inwestycyjne pozyskiwania ciepła. Ciepło niskotemperaturowe pozyskiwane jest najczęściej za pomocą wentylatorowych wymienników ciepła, które jednak nie są pozbawione pewnych wad. Niektóre z tych wad mogą zostać wyeliminowane dzięki zastosowaniu wymienników typu "sopel lodu". Celem artykułu jest przedstawienie metody przeprowadzania projektowych obliczeń cieplnych parowaczy typu "sopel lodu", stanowiących ujęcie dolnego źródła ciepła powietrznych pomp ciepła. Zaprezentowano w artykule własny algorytm obliczeniowy, służący do wyznaczania wydajności cieplnej parowacza o znanej konstrukcji. Sposób prowadzenia obliczeń został zilustrowany przykładem obliczeniowym. Parowacze typu "sopel lodu" nie emitują hałasu i nie wymagają odszraniania powierzchni wymiany ciepła. Ich sprawność działania jest wyższa w przypadku zapewnienia właściwej ekspozycji na wiatr. Dlatego wymienniki te powinny być tak usytuowane, aby zapewniony był swobodny przepływ powietrza ze wszystkich stron. Pompy ciepła z parowaczami typu "sopel lodu" mogą stanowić alternatywę dla powietrznych pomp ciepła z parowaczami, w których przepływ powietrza wymuszony jest wentylatorem.

EN

Atmospheric air is widely available low temperature heat source for heat pumps. Using air source heat pumps does not cause any disturbance of the heat balance and it is characterized by relatively low investment costs of heat intake. Obtaining low temperature heat is most frequently realized by fan heat exchangers which are not devoid of certain defects though. Some of these limitations can be resolved thanks to the use of "ice-stick" type evaporator. The aim of the paper is to present the method of carrying out design thermal calculations of "ice-stick" type evaporators which are the low heat source intakes of air source heat pump. The own computational algorithm is presented in the paper. It is used to determine the thermal load of the known con- struction evaporator. The calculation method is illustrated by a calculation example. The “ice-stick” type evaporators do not emit noise and do not require defrosting of heat exchange surface area. Their efficiency is higher if the proper wind exposure is ensured. Therefore these exchangers should be positioned so as to ensure the free air flow from all sides. The heat pumps with "ice-stick" type evaporator can be an alternative to air source heat pumps equipped with evaporators where the air flow is forced by a fan.

6

Projektowe obliczenia cieplne skraplaczy i parowaczy płytowych

Zalewski Wojciech, Kopeć Piotr

Chłodnictwo i Klimatyzacja

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2019

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nr 8

38--44

PL

W artykule autorzy zaprezentowali kompletne algorytmy obliczeniowe, które można wykorzystać do projektowania wymienników płytowych, powszechnie stosowanych jako skraplacze i parowacze do ujęcia dolnego i górnego źródła ciepła w pompach ciepła. Materiał zawiera również praktyczne zastosowanie prezentowanych algorytmów w postaci przykładów obliczeniowych.