Wyniki wyszukiwania - Biblioteka Nauki

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Neural network structure optimization algorithm

100%

Nowakowski G. , Dorogyy Y. , Doroga-Ivaniuk O.

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2018

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tom Vol. 12, No. 1

5--13

EN

This paper presents a deep analysis of literature on the problems of optimization of parameters and structure of the neural networks and the basic disadvantages that are present in the observed algorithms and methods. As a result, there is suggested a new algorithm for neural network structure optimization, which is free of the major shortcomings of other algorithms. The paper describes a detailed description of the algorithm, its implementation and application for recognition problems.

2

Groundwater mapping of urban and coastal areas in Brunei

75%

Abidin H. , Azffri S. L. , Nirus E. , Suhip A. , Jaya A. A. , Gödeke S. H.

Journal of Water and Land Development

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2024

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tom no. 61

21--29

EN

Groundwater mapping plays an important role in effective water resource management, sustainable development, and environmental protection. In the tropical Brunei Darussalam (north Borneo Island), groundwater mapping is yet to be provided. The aim of the study is to provide groundwater mapping of Brunei, particularly for the urban and coastal areas of the Brunei-Muara capital district. The study uses a GIS interpolation technique to generate a groundwater contour map based on groundwater data from 572 sacrificial boreholes located in the study area. Remote sensing data and published maps from secondary sources were digitised in ArcGIS software to produce thematic layers for further hydrological evaluations. Results showed that groundwater levels in the study area are generally high and shallow, ranging from 0 to 18 m below ground level with a mean value of 2.9 m. According to the evaluation of geo-thematic layers and groundwater contours, groundwater flows towards the South China Sea in the coastal areas and towards the Brunei River further inland. Hydraulic gradients towards the South China Sea also vary between 0.004 and 0.08. Thus, assuming surface aquifer thickness in the weathered zone between 10 to 20 m, hydraulic conductivities ranges from 1∙10-5 to 1∙10-4 m∙s-1, a submarine groundwater discharge (SGD) flux between 4.7∙10-7 to 4.0∙10-4 m3 ∙s-1 per unit width can be estimated for the shallow aquifer. This study provides valuable insights into the groundwater system dynamics so important, which are critical for its future utilisation and protection, aiming to contribute to the national water security in Brunei Darussalam.

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Wpływ stosowanych praktyk rolniczych na dopływ wód podziemnych oraz azotanów do Zatoki Puckiej

71%

Potrykus D.

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tom Vol. 72, nr 1

15--25

EN

Eutrophication of marine baśni associated with submarine groundwater discharge is currently one of the most important challenges in modern coastal hydrogeology, and is classified as a serious global environmental problem. Aparticular source of groundwater pollution is agricultural activity, which is commonly carried out in the coastal zone. Research was conducted on arepresentative part of the Bay of Puck watershed, dominated by agriculturall anduse. The geological setting of the study area is heterogeneous, which has a significant influence on groundwater flow and occurrence in the multi-aquifer hydrosystem, draining into Puck Bay. The impact of agricultural practices on groundwater and nitrate discharge to the Puck Bay was determined, byan integrated modeling approach, developed using combination of the SWAT, MODFLOW-NWT and MT3DMS codes. Spatial and seasonal variations of the N-NO3 load leached from the soil profile and the infiltration of precipitation are convergent with observed trends in the discharge of groundwater and N-NO3 loads into Puck Bay. The simulations show that 1,355.13 m3/h of ground- waterand1.87kg/h (16. 4 t/year) of N-NO3 loadare discharged into Puck Bay from the aquifers analyzed, the majority of which comes froman upper aquifer. The distribution of the values as determined was found to be influenced by agricultural practices, resulting from changes in crop structure, fertilizer management, cultivation methods and grazing.

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Significance of nutrient fluxes via submarine groundwater discharge in the Bay of Puck, southern Baltic Sea

63%

Szymczycha B. , Kłostowska Ż. , Lengier M. , Dzierzbicka-Głowacka L.

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2020

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tom No. 62 (2)

117--125

EN

In this study, we collected submarine groundwater discharge (SGD) and seawater samples at six sites in the Bay of Puck, in the southern Baltic Sea, in order to estimate the nutrient distribution in groundwater affected areas. In addition, we estimated nutrient fluxes via SGD, including both fresh SGD (FSGD) and recirculated seawater SGD (RSGD), to the entire Bay of Puck. Phosphate (PO43−) concentrations varied significantly among study sites and seasons, while both ammonium (NH4+) and nitrates (NO3−) concentrations varied only seasonally. The N:P ratio indicated P limitation in most of the samples. The estimated seasonal and annual loads, via SGD, of both dissolved inorganic nitrogen (DIN; 9303 t yr−1) and PO43− (950 t yr−1), were the most significant source of nutrients to the Bay of Puck, and notably higher than quantified before (FSGD nutrient loads of 50 t yr−1 and 56 t yr−1 for DIN and PO43−, respectively). The SGD fluxes reported here indicate some of the highest rates of sediment-water fluxes reported in the Baltic Sea. These results suggest that SGD (both FSGD and RSGD) should be considered as source of chemical substances to the marine environment.

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Bezpośrednie pomiary podmorskiego zasilania wodami podziemnymi Zatoki Puckiej

63%

Bublijewska E. , Łęczyński L. , Marciniak M. , Chudziak Ł. , Kłostowska Ż. , Zarzeczańska D.

Przegląd Geologiczny

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2017

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tom Vol. 65, nr 11/2

1173--1178

EN

Fresh water accumulated beneath the sea floor may flow through sediments into the sea water. This process, opposite to infiltration, is called Submarine Groundwater Discharge (SGD). The Southern Baltic Sea coastal zone represents an interesting object of study because its bottom deposits show seepages of fresh groundwater. The study involved Puck Bay and the adjacent coastal belt of the Kashubian Coast plateau. Research of potential outflows of fresh groundwater was done through a thermal imaging of the study area. An articulate thermal anomaly allowed predetermining the location of research points. Groundwater outflows in the seabed were confirmed by measurements of chloride content and electrical conductivity of water samples. The paper presents two new devices: a filtrometer that enables measurement of water filtration intensity during drainage, and a gradientmeter that measures the hydraulic gradient. The use of both devices allows determination of the in situ hydraulic conductivity. Results of the research have shown relationships between fresh groundwater and the sea-bottom sediments.