Wyniki wyszukiwania - BazTech

1

Passenger traffic in Polish seaports in the face of the COVID-19 pandemic

Sobczuk Sebastian, Borucka Anna

Zeszyty Naukowe Politechniki Morskiej w Szczecinie

|

2025

|

nr 81 (153)

57--66

EN

The outbreak of the COVID-19 pandemic had a profound impact on the global economy and disrupted daily life across many regions of the world. Restrictions imposed at the time, such as the closure of national borders and restrictions on mobility, led to unprecedented challenges for the transportation sector and related tourism services compared with any prior crisis. This disruption also affected maritime passenger transport in Poland. This article aims to assess the impact of the COVID-19 pandemic on passenger traffic in Polish seaports and to develop mathematical models that could support management in the event of future epidemic threats. Three different models are proposed, which showed that the epidemic crisis resulted in a significant decline in passenger traffic at Polish seaports. The most accurate proved to be the SARIMA model. The Holt-Winters model also demonstrated high fitting and predictive performance. In turn, the STL model offered intriguing insights with its time series decomposition, enabling a detailed analysis of individual components. A comparative analysis of the proposed models confirms their usefulness in forecasting passenger traffic in seaports in the face of disruptions such as the COVID-19 pandemic. These models can be an effective decision-support tool, helping to reduce the negative effects of future epidemic threats.

2

Distribution of fire activity in Africa, criticism of previous explanations based on a data base from 2001 to 2021

Mourjane Mohammed, Tabyaoui Hassan, El Hammichi Fatima

Studia Quaternaria

|

2025

|

Vol. 42, Nr 1

75--80

EN

Africa is the continent most exposed to fires, accounting for over half of the burned areas and pyrogenic greenhouse gas emissions globally. Fire seasonality in Africa follows the dry seasons, primarily from October to March for the Northern Hemisphere, with a peak in December–January, and from April to October for the Southern Hemisphere, with a peak in August. In 2001, we monitored active fires monthly, observing significant changes based on the seasons. The equatorial and southern regions of Africa showed a higher concentration of fires, less in the north. This variation has been consistent for 21 years, up to 2021. A strong correlation exists between the latitude of African regions and fire abundance. Equatorial countries experience more fires during the period between December and March, while southern countries see more during the other time of year period. Key factors include the accumulation of biomass, which fuels fires during the rainy season, and increasing human pressure, especially due to the need to warm up.

3

Variability of the lowest monthly precipitation sums in the Silesian and Żywiec Beskids

Wałęga Agnieszka, Cebulska Marta, Ziernicka-Wojtaszek Agnieszka, Młocek Wojciech

Journal of Water and Land Development

|

2025

|

no. 66

89--97

EN

The study was based on monthly precipitation sums from at eight precipitation stations in the Silesian and Żywiec Beskids, covering the period 1951-2022. The data were obtained from the Institute of Meteorology and Water Management - National Research Institute. The frequency and year-to-year variability of the precipitation sums, as well as seasonal variability, based on Colwell’s predictability index (P) and its components: constancy (C) and seasonality (M). The results show that low precipitation occurred in all months of the year, with the highest frequency in October, and sporadically recorded in May, June, and July. The majority of the lowest monthly precipitation sums ranged between 30-50 mm, although in some, values exceeded 65 mm. Dry months were recorded in the study period of 1951-2022, notably October 1951, when precipitation sums at the stations did not exceed 3.5 mm, and November 2011, when they did not exceed 1.5 mm. Compared to the long-term average, these precipitation sums accounted for less than 5%. No significant trend was observed in the lowest monthly precipitation sums, though short-term fluctuations were present. Analysis of Colwell’s indices showed that the predictability of the lowest annual precipitation sums was below average, at approximately 0.40 across the analysed stations. Seasonality (M) was the dominant component of predictability, accounting for an average of 71% of the total predictability. The research findings may contribute to the understanding of the variability and forecasting of extreme meteorological droughts in the Polish Carpathians, particularly with implications for agriculture and forestry.

4

The influence of seasonality of microgrids connected to the power system on selected power quality parameters

Bątkiewicz-Pantuła Marta

Archives of Thermodynamics

|

2025

|

Vol. 46, no. 1

185--191

EN

The article presents an assessment of the parameters of power quality obtained from renewable sources. The assessment was based on the Decree of the Minister of Climate and Environment of March 22, 2023 on detailed conditions for the operation of the electricity system (Dz. U. 2023 r., 819) and the EN 50160: 2010 standard - Parameters of supply voltage in public power grids. The analysis was carried out on the example of actual measurements of power quality parameters. The measurements were made with a Fluke 1760 power quality analyser. The analyser was installed at the point of connection to the renewable energy grid. The article analyses and compares renewable energy sources. The assessment of power quality parameters was carried out on the basis of the discussed analyses. The article presents the influence of seasonality on the parameters of power quality.

5

Dependence of seasonal phenomena in coordinate time series on GNSS antenna mounting height

Maciuk Kamil, Olejarz Grzegorz, Abdelhamid Mohamed, Bem Agata, Krawczyk Karol, Postek Paweł, Maciejewska Aleksandra

Advances in Geodesy and Geoinformation

|

2025

|

Vol. 74, no. 1

art. no. e60, 2025

EN

The purpose of this paper is analysing the correlation between the magnitude of the annual amplitude of seasonal changes in the coordinate components of GNSS reference stations and the height of the antenna mounting above the ground. For this purpose, the daily coordinate solutions of more than 500 GNSS reference stations that are part of the IGS (International GNSS Service) network were studied due to their distribution across the globe and long operating time, for some stations dating back to the 1990s. To minimize the impact of the tectonic plate movements authors adopted coordinates of reference stations inside each of the 21 tectonic plates. The coordinates in a topocentric reference frame were detrended in accordance with a linear model, with the objective of removing first-order trends. Subsequently, the seasonal yearly functions were calculated for each North, East and Up component. Finally, the amplitude of the seasonal factor for each station was determined. As a result of the analysis, the existence of annual amplitudes of coordinate changes was demonstrated for some of the stations, but no significant correlation between this phenomenon and the height of the GNSS antenna mounting was shown. In the case of the horizontal components, the majority of the station’s time series is characterized by the amplitude of seasonal function does not exceed 2.5–3 mm, and 5 mm for the vertical component.

6

Seasonality in the Design of the Environment of a Hotel Facility on the Example of the Rest House for Employees of Lublin University of Technology in Kazimierz Dolny

Hołownia Damian, Lisiewska Dominika

Teka Komisji Architektury, Urbanistyki i Studiów Krajobrazowych

|

2024

|

T. 20, nr 2

51--61

EN

The authors analyse the impact of seasonality on the design of the environment of hotel facilities. As a case study, the Rest House for Employees of Lublin University of Technology in Kazimierz Dolny was chosen. The problem of variability of climatic conditions, and various forms of tourist activities, which require a flexible approach to design, allowing year-round use of space, is addressed. Both examples of space development in Poland and specific seasonal solutions for Kazimierz Dolny were discussed. An analysis of local conditions, including landscape values and cultural heritage of the city, was conducted. Proposals are presented for adapting the space around the rest house, taking into account the organization of spring and summer outdoor events, autumn cultural revival and winter recreational activities. Drawings of solutions for the recreational zones of the space around the Rest House of Lublin University of Technology are an integral part of the study. The article emphasizes that flexible space design can increase interest in the recreational facility and contribute to the development of the year-round offer of Kazimierz Dolny.

7

Seasonal enhancement of phytoplankton biomass in the southern tropical Indian Ocean: Significance of meteorological and oceanography parameters

Karnan Chinnadurai, Gautham Sreedharan

Oceanologia

|

2024

|

No. 66 (2)

196--219

EN

The present study focused on understanding the seasonality of the phytoplankton biomass (chlorophyll a) distribution in the oligotrophic, Equatorial, and Southern Tropical Indian Ocean (ESTIO; 0–30°S and 60–90°E). The long-term satellite data analyses (2003–2020) showed a strong seasonality in sea surface temperature (SST), wind, currents, mean sea level anomaly (MSLA), photosynthetically available radiation (PAR), euphotic depth (ZEU) and mixed layer depth (MLD). As a response to the hydrographical changes, the phytoplankton biomass showed noticeable seasonal variation with the highest biomass during the Austral Winter (AW; June–September; avg. 0.11 ± 0.03 mg/m³) and lowest during the Austral Summer (AS; November–February; avg. 0.07 ± 0.03 mg/m). High chlorophyll patches (>0.1 mg/m³) were found between 0°–8°S during the AS and expanded over 0°–18°S during the AW. As multi-year mean chlorophyll a was higher (>0.1 mg/m³) in the northern part of the ESTIO (north of ∼13°S; HCD: high chlorophyll a domain) than the southern side (LCD: low chlorophyll a domain), the study area was divided into two domains and all the variables were analysed. In the HCD, enhancement of chlorophyll a was positively correlated with variables such as wind speed, wind stress, Ekman pumping, stronger northward and westward winds, as well as the presence of cyclonic eddies. These features are likely to stimulate primary production by uplifting the thermocline and enhancing nutrient supply. In the LCD, mixed layer depth also showed a strong positive correlation with elevated chlorophyll a, apparently because it is deep throughout the year (thereby keeping lower biomass) and deepens more strongly in winter than in the HCD. Another contrast with the HCD is that the cyclonic eddies appear to be insufficiently abundant to influence its chlorophyll a. Pearson's multivariable correlation analysis and principle component analysis confirmed the statistical significance of the above parameters on the enhancement of chlorophyll a in the ESTIO.

8

Analysis of seasonal crustal deformation characteristics in Dali, Yunnan using GPS observations

Shen Xing, Liu Xikang, Shen Yu, Song Chengke, Yin Haiquan, Chen Zhaohui

Acta Geophysica

|

2024

|

Vol. 72, no. 3

1473--1482

EN

This paper extracts and separates seasonal term of GPS (Global Positioning System) time series based on empirical mode decomposition and wavelet transformation. Through time series analysis of 9 GPS continuous stations in Dali, Yunnan, it is found that the vertical (U), north-south (N) and east-west (E) components of the relative motion have distinct annual and semi-annual period components. In the vertical direction, the U component has the strongest seasonal deformation characteristics, on the annual period term, between each station the correlation coefficient reaches 0.98, this is consistent with the relevant research results of many researchers; In horizontal direction, seasonal deformation is also more significant, the N component annual and semi-annual period signals are more obvious and the correlation coefficient is high, but the E component 9 stations signal are relatively scattered and poorly correlated. On the semi-annual period, the N and U directions have a very obvious and consistent semi-annual periodicity, and their two correlation coefficient numbers are 0.95 and 0.94 on average, respectively, the N and E are negatively correlated with a correlation coefficient of -0.98. In time series trend term, 9 stations show southeast movement in horizontal direction, but have great differences in vertical movement trend. Among them, YNLJ, YNYS, YNSD and YNLC are linear uplift movement with good consistency. YNYA, YNCX and YNJD show overall uplift movement, but with subsidence fluctuation, the trend of the three stations is very similar, with an average correlation coefficient reaches 0.8; XIAG station shows uplift movement as a whole, the relative motion trend in the E direction is very different from other stations in phase and amplitude, probably because it is closer to the Erhai lake and more susceptible to the influence of water level changes; YNYL also has different motion changes at different times, but the overall performance is subsidence motion. The analysis suggests that the GPS time series contains rich information on the seasonal deformation of the Earth’s crust, and precipitation has an important role in influencing the seasonal deformation of continuous stations.

9

Analysis of seasonality and causes of equipment and facility failures in electric power distribution networks

Chojnacki Andrzej Ł.

Przegląd Elektrotechniczny

|

2023

|

R. 99, nr 1

157--163

EN

The article presents the results of analyses concerning the seasonality and causes of damage to equipment and facilities operated in 110kV, MV and LV power distribution networks. These facilities include 110kV overhead lines, 110kV/SN substations, MV overhead and cable lines, MV/LV overhead and indoor substations, and LV overhead and cable lines. Months with increased failure rates of individual devices were identified. The most common causes of failure of electric power facilities have been identified. The analysis was based on failures that occurred over a ten-year period at a major electricity distribution company in the country.

PL

W artykule przedstawiono wyniki analiz dotyczących sezonowości oraz przyczyn uszkodzeń urządzeń i obiektów eksploatowanych w elektroenergetycznych sieciach dystrybucyjnych 110kV, SN oraz nn. Do obiektów tych zalicza się linie napowietrzne 110kV, stacje 110kV/SN, linie napowietrzne i kablowe SN, stacje elektroenergetyczne SN/nn napowietrzne i wnętrzowe oraz linie nn napowietrzne i kablowe. Wskazano miesiące o zwiększonej awaryjności poszczególnych urządzeń. Zidentyfikowano najczęstsze przyczyny awarii obiektów elektroenergetycznych. Analizy zostały przeprowadzone na podstawie awarii, które wystąpiły w okresie dziesięciu lat na terenie dużej spółki dystrybucyjnej energii elektrycznej w kraju.

10

Seasonal precipitation variation in central-eastern Poland

Radzka Elżbieta, Rymuza Katarzyna

Journal of Water and Land Development

|

2023

|

no. 59

76--82

EN

The purpose of the work is to characterise pluvial conditions in central-eastern Poland from the beginning of the 21st century (2001-2020). The analysis involved seven meteorological stations of the Institute of Meteorology and Water Management - National Research Institute (IMGW-PIB): Białowieża, Legionowo, Pułtusk, Siedlce, Szepietowo, Terespol and Warsaw. The work contains the analysis of the annual and seasonal atmospheric precipitation pattern (summer, winter, spring and autumn) and its temporal and spatial variation throughout a 20-year period. Moreover, the percentage share of precipitation in each season in the annual sum was calculated. In order to analyse precipitation patterns in the study period, the Innovative Trend Analysis (ITA) was applied. The average long-term annual atmospheric precipitation sum ranged from 557 mm at Terespol to 653 mm at Białowieża. The highest seasonal precipitation sum in the studied region was recorded for the summer (218 mm) whereas in spring and autumn, precipitation stayed at a similar level and amounted to 130 and 131 mm, respectively. The lowest precipitation was recorded in winter (109 mm). The highest percentage share of the atmospheric precipitation sum was associated with summer rainfall (from 35 to 38%), whereas the lowest in winter (from 18 to 20%). Comparisons of 2001-2010 and 2011-2020 decades revealed a decline in the share of summer precipitation in the annual sum at most of the stations, and an increase in the share of winter precipitation. The ITA demonstrated that the most significant trends in precipitation change occurred in summer and winter and the directions of the trends were different for each station.

11

Assessment of the stability of mercury concentrations in municipal waste using data science tools

Jędrusiak Radosław, Chuchro Monika, Bielowicz Barbara, Gielar Agnieszka

Geology, Geophysics and Environment

|

2023

|

Vol. 49, no. 1

71--83

EN

Mercury and its compounds are among the most dangerous and toxic substances in the environment. As part of the study, several exploratory analyses and statistical tests were conducted to demonstrate how low and stable mercury content is in municipal waste. A statistical analysis of the mercury content in waste (waste codes 19 12 12 and 20 03 01) was carried out using advanced IT tools. Based on 32 results for each waste, the maximum mercury concentration was 0.062 mg/kg dry weight (EWC code 19 12 12) and 0.052 mg/kg dry weight (EWC code 20 03 01). The analysis, data inference, and modeling were performed according to the CRISP-dm methodology. The results obtained were compared with the maximum allowable mercury concentrations for agricultural soils (2 mg/kg dry weight) and the provisions of the Minamata Convention (1 mg/kg). The average, median, and maximum observed mercury concentrations in waste are significantly lower than the assumed levels of 2 mg/kg (permissible concentrations for II-1 soils) and 1 mg/kg (Minamata Convention). The stability of mercury content in waste was examined. Descriptive statistics, statistical tests, and regression modeling were used. The tests and analyses performed showed an insignificant variation in the mercury content of the wastes with codes 19 12 12 and 20 03 01. No trend or seasonality was observed. The analyses and tests performed confirmed that the data are stable, and the values are low.

12

Arima Model optimal selection for time series forecasting

Romanuke Vadim

Maritime Technical Journal

|

2022

|

nr 1 (224)

28--40

EN

A fast-and-flexible method of ARIMA model optimal selection is suggested for univariate time series forecasting. The method allows obtaining as-highly-accurate-as-possible forecasts auto-matically. It is based on effectively finding lags by the autocorrelation function of a detrended time series, where the best-fitting polynomial trend is subtracted from the time series. The fore-casting quality criteria are the root-mean-square error (RMSE) and the maximum absolute error (MaxAE) allowing to register information about the average inaccuracy and worst outlier. Thus, the ARIMA model optimal selection is performed by simultaneously minimizing RMSE and Max-AE, whereupon the minimum defines the best model. Otherwise, if the minimum does not exist, a combination of minimal-RMSE and minimal-MaxAE ARIMA models is used.

PL

W pracy zaproponowano szybką i elastyczną metodę optymalnego doboru modelu ARIMA na potrzeby prognozowania szeregów czasowych z jedną zmienną. Metoda pozwala na uzyskanie możliwie najdokładniejszych prognoz, opierając się na skutecznym znajdowaniu opóźnień. Po-szukiwanie opóźnień realizowane jest za pomocą funkcji autokorelacji szeregu czasowego bez trendu, w którym najlepiej dopasowany trend wielomianowy jest odejmowany od szeregu cza-sowego. Za kryteria jakości prognozowania przyjęto średni błąd kwadratowy (RMSE) i maksy-malny błąd bezwzględny (MaxAE), które pozwoliły na rejestrację informacji o średniej i maksymalnej niedokładności. Optymalny dobór modelu ARIMA odbywa się poprzez jednoczesną minimalizację RMSE i MaxAE, dla której wartość minimalna określa najlepszy model. W przeciw-nym razie, jeśli minimum nie istnieje, używana jest kombinacja modeli ARIMA z minimalnym RMSE i minimalnym MaxAE.

13

Survival Strategies and Seasonal Size Variations of Feather Mites Proctophyllodes megaphyllus on their Host Alpine Accentor Prunella collaris

Marčanová Natália, Janiga Marián

Polish Journal of Ecology

|

2021

|

Vol. 69, nr 1

25--34

EN

Compared to chewing lice, symbiotic and studies on their biology, ecology and survival strategies are still rare. To describe the ecology and morphology of the mite species Proctophyllodes megaphyllus, a symbiont of the alpine accentor Prunella collaris, 150 accentors were captured in the West Carpathian Mountains of Slovakia. The mites extracted from the birds were sexed and their specific body structures were measured. In total 2144 individuals of P. megaphyllus were collected from 100 accentors. Male mites collected in autumn, after the bird's postnuptial moult, reached the largest size. At the same time, mite prevalence reached maximum while the mean intensity of infestation was at its lowest. Our results suggest that mites preferred newly coated feathers after a moult and radiated horizontally, infesting birds at shared roosting sites where alpine accentors tend to reoccur. This study is one of the few evaluations of seasonal variation in ecology and morphology of feather mites in alpine conditions.

14

Evaluating annual and seasonal patterns of suspended sediment loads in a semi-arid watershed, central Algeria

Rabah Mosbah, Bouchelkia Hamid, Belarbi Fadila, Millares Agustin

Journal of Water and Land Development

|

2021

|

no. 50

158--172

EN

Soil loss is a major problem for watersheds management in semi-arid environments. The objective of the present study is to analyze the annual and seasonal patterns of suspended loads and quantify the specific sediment yields in a semi-arid environment of the Mazafran Watershed in central Algeria. The obtained information of water discharge and suspended sediment load, recorded during 19 years, was confronted with precipitation data in order to establish the relationships between theforcing agents and erosive processes. The specific sediment yield was estimated by assessing rating curve data under two types of identified responses. The obtained results allowedconfirming the seasonality on suspended sediment transport in the studied basin, which accounts for 56% of the total suspended sediment load estimated in winter. The mean annual suspended sediment is estimated at 17.52 Mg∙ha–1·y–1. The results highlighted that the type 2 event dominates the production of sediment in the study area in comparison with type 1 event. The analysis of the variability of rainfall erosivity index showed that there is a strong correlation between the annual precipitation and modified Fournier index (MFI), and a weak correlation with the monthly precipitation concentration index (PCI). Moreover, the spatial distribution of the modified Fournier index at the basin scale showed the highest precipitation aggressiveness in the Southern part of the study region for both type of events, whereas the precipitation aggressiveness low to moderate in the remaining part of the study region.

15

Frequency of failures in selected urban vehicle systems

Rymarz Joanna

Zeszyty Naukowe Akademii Morskiej w Szczecinie

|

2020

|

nr 64 (136)

9--13

EN

The aim of this study was to examine the relationship between the occurrence of selected types of failures and the time and season of their occurrence in public transport buses in the city of Lublin. The analysis was carried out for buses operated in the Municipal Transport Company within the past 3 years. The chi-squared analysis showed that during operation, there are significant differences between the failures and the annual season, but there are no differences between the frequency of failures and the time of day.

16

Detectability of Elusive Reptiles under Artificial Cover Objects is Species- and Year-Specific

Kolanek Aleksandra, Bury Stanisław

Polish Journal of Ecology

|

2020

|

Vol. 68, nr 4

342--347

EN

Field surveys of rare and elusive reptiles often encounter the problem of low detectability. Therefore, several techniques have been invented to improve detection probability and artificial cover objects (ACOs) are among the most commonly used in reptile studies. However, the methodological effectiveness of ACOs has been rarely evaluated and focused mostly on spatial aspects. The temporal dimension of the ACOs effectiveness remains still understudied, despite well-known seasonal variation in reptile activity patterns. Here, we examined seasonal and between-year variation in the fraction of occupied ACOs, as a proxy for detectability, in two elusive reptile species, the slow worm Anguis fragilis and smooth snake Coronella austriaca. We found that the use of ACOs was species-specific and showed high temporal variation. In the case of smooth snakes, monthly usage varied between years; specifically within-year variation of the proportion in occupied ACOs was most pronounced in 2015, but seems vanishing in consecutive years. This loss of of seasonal pattern occurs only in the last year of survey in the case of slow worm and monthly use of ACOs seem not to vary between years. Considerably low detectability of the studied species by the ACO method in some years may not necessarily indicate their low population density, but rather results from shifts in their diurnal activity and/or microhabitat use dependent on ambient temperatures. Increasing between-year variation in weather conditions may reduce repeatability of seasonal patterns of ACO usage, making we suggest additional detection techniques that could bee incorporated.

17

Sezon na kruszywa

Stachowski Maciej

Surowce i Maszyny Budowlane

|

2019

|

nr 2

18—21

PL

Sezonowość można traktować jako czynnik zewnętrzny, na występowanie którego przedsiębiorstwo zbytnio nie ma wpływu. Problem dotyka również górnictwa, zwłaszcza odkrywkowego, mającego styczność z warunkami naturalnymi. W tym wypadku rodzi się pytanie: jakie problemy niesie za sobą sezonowość branży kruszyw?

18

Modeling of transport processes in terms of seasonality of transport

Świderski Andrzej

Scientific Journal of Polish Naval Academy

|

2019

|

R. 60 nr 1 (216)

103--116

EN

The company’s success depends on many factors. One of them is the ability to meet the customers’ expectations and adjust to the needs reported by market. Mathematical methods and tools are helpful in assessing demand. Forecasts should take into account all factors shaping the demand for goods and services, but they are often difficult to define, not only because of their large number, but also due to the impact of individual variables, which is difficult to determine. In many cases, the number of placed orders strongly depends on the time at which they are submitted. The needs can vary according to the time of day, week and year. Then we are dealing with the so-called seasonality, the inclusion of which is very important in the company and enables to better adapt its activity to the customers’ requirements. This article describes the seasonality of demand in a company providing domestic and road transport services with high-tonnage vehicles. The validity of such analyses and potential benefits were indicated.

PL

Sukces przedsiębiorstwa zależy od wielu czynników. Jednym z nich jest zdolność do spełnienia oczekiwań klientów i dopasowanie do potrzeb zgłaszanych przez rynek. Pomocne w ocenie popytu są metody i narzędzia matematyczne. Formułowane prognozy powinny brać pod uwagę wszystkie czynniki kształtujące zapotrzebowanie na dobra i usługi, jednak często są one trudne do zdefiniowania, nie tylko ze względu na znaczną ich liczbę, ale również na trudny do określenia wpływ poszczególnych zmiennych. W wielu przypadkach liczba złożonych zamówień silnie zależy od czasu, w którym są one składane. Potrzeby mogą być zróżnicowane w zależności od pory dnia, tygodnia czy roku. Wówczas uaktywnia się tzw. sezonowość, której uwzględnienie jest bardzo istotne w przedsiębiorstwie i pozwala lepiej dostosować jego działalność do wymagań klientów. W artykule dokonano charakterystyki sezonowości popytu w firmie świadczącej usługi transportu krajowego drogowego realizowanego pojazdami wysokotonażowymi. Wskazano zasadność prowadzenia takich analiz i potencjalne korzyści.

19

Modelowanie procesów transportowych z uwzględnieniem sezonowości przewozów

Świderski A.

Rocznik Bezpieczeństwa Morskiego

|

2018

|

R. XII

91--105

PL

Sukces przedsiębiorstwa zależy od wielu czynników. Jednym z nich jest zdolność do spełnienia oczekiwań klientów i dopasowanie do potrzeb zgłaszanych przez rynek. Pomocne w ocenie popytu są metody i narzędzia matematyczne. Formułowane prognozy powinny brać pod uwagę wszystkie czynniki kształtujące zapotrzebowanie na dobra i usługi, jednak często są one trudne do zdefiniowania, nie tylko ze względu na znaczną ich liczbę, ale również na trudny do określenia wpływ poszczególnych zmiennych. W wielu przypadkach liczba złożonych zamówień silnie zależy od czasu, w którym są one składane. Potrzeby mogą być zróżnicowane w zależności od pory dnia, tygodnia, roku. Wówczas uaktywnia się tzw. sezonowość, której uwzględnienie jest bardzo istotne w przedsiębiorstwie i pozwala lepiej dostosować jego działalność do wymagań klientów. W niniejszym artykule dokonano charakterystyki sezonowości popytu w firmie świadczącej usługi transportu krajowego, drogowego, realizowanego pojazdami wysokotonażowymi. Wskazano zasadność prowadzenia takich analiz i potencjalne korzyści.

EN

The company’s success depends on many factors. One of them is the ability to meet the customers’ expectations and adjust to the needs reported by market. Mathematical methods and tools are helpful in assessing demand. Forecasts should take into account all factors shaping the demand for goods and services, but they are often difficult to define, not only because of their large number, but also due to the impact of individual variables, which is difficult to determine. In many cases, the number of placed orders strongly depends on the time at which they are submitted. The needs can vary according to the time of day, week and year. Then we are dealing with the so-called seasonality, the inclusion of which is very important in the company and enables to better adapt its activity to the customers’ requirements. This article describes the seasonality of demand in a company providing domestic and road transport services with high-tonnage vehicles. The validity of such analyses and potential benefits were indicated.

20

Spatiotemporal changes in the concentration and composition of suspended particulate matter in front of Hansbreen, a tidewater glacier in Svalbard

Moskalik M., Ćwiąkała J., Szczuciński W., Dominiczak A., Głowacki O., Wojtysiak K., Zagórski P.

Oceanologia

|

2018

|

No. 60 (4)

446--463

EN

Tidewater glaciers supply large amounts of suspended particulate matter (SPM) and freshwater to fjords and affect oceanographic, sedimentological and biological processes. Our understanding of these processes, is usually limited to the short summer season. Here, we present the results of a one-year-long monitoring of the spatial variability in SPM characteristics in a context of oceanographic and meteorological conditions of a glacial bay next to Hansbreen, a tidewater glacier in Hornsund (southern Spitsbergen). The observed range of SPM concentrations was similar to ranges measured in other sub-polar glaciated fjords, especially in Svalbard. The major source of SPM is the meltwater discharge from the glacier. The maximum water column-averaged SPM concentrations did not correlate with peaks in freshwater discharge and were observed at the beginning of the autumn season, when the fjord water transitioned from stratified to fully mixed. The observed spatiotemporal variations in the total SPM, particulate organic matter (POM) and particulate inorganic matter (PIM) are likely controlled by a combination of factors including freshwater supply, water stratification and circulation, bathymetry, the presence of sea ice, biological productivity and sediment resuspension. During the ablation season, the SPM maximum concentrations were located within the upper water layer, whereas during the winter and spring, the greatest amounts of SPM were concentrated in deeper part. Thus, typical remote sensing-based studies that focus on SPM distributions may not reflect the real SPM levels. POM and PIM concentrations were correlated with each other, during most of the time suggesting that they may have a common source.