TY  - ART
AU  - Halmai, Ákos
TI  - Example code for "Paul Bourke, 1998: Determining whether or not a polygon (2D) has its vertices ordered clockwise or counter-clockwise".
PY  - 2023
UR  - https://m2.mtmt.hu/api/publication/34571802
ID  - 34571802
N1  - https://paulbourke.net/geometry/polygonmesh/AreaClockwiseConcave.txt
https://paulbourke.net/geometry/polygonmesh
AB  - # Ákos Halmai, 2023.
import math


def getArea(points) -> float:
    """Expects iterable of two-element-tuples.
    For example:
    points = ((0, 0), (1, 0), (1, 1), (0, 1), (0, 0))"""

    area = 0.0
    (x1, y1) = points[0]
    for (x2, y2) in points[1:]:
        area += x1 * y2 - y1 * x2
        (x1, y1) = (x2, y2)

    return 0.5 * area


def getAreaAbs(points) -> float:
    """Expects iterable of two-element-tuples.
    For example:
    points = ((0, 0), (1, 0), (1, 1), (0, 1), (0, 0))"""

    # Returns float (always):
    return math.fabs(getArea(points))


def getAreaPrecise(points) -> float:
    """Expects iterable of two-element-tuples.
    For example:
    points = ((0, 0), (1, 0), (1, 1), (0, 1), (0, 0))"""

    def getPartArea(points):
        (x1, y1) = points[0]
        for (x2, y2) in points[1:]:
            yield x1 * y2
            yield -y1 * x2
            (x1, y1) = (x2, y2)

    # Avoids loss of precision by tracking multiple
    # intermediate partial sums:
    return 0.5 * math.fsum(getPartArea(points))


def getAreaPreciseAbs(points) -> float:
    """Expects iterable of two-element-tuples.
    For example:
    points = ((0, 0), (1, 0), (1, 1), (0, 1), (0, 0))"""

    # Returns float (always):
    return math.fabs(getAreaPrecise(points))


def __isClockwise(*args) -> bool:
    """Private. Do not use it!"""

    (x0, y0), (x1, y1), (x2, y2), *_ = args
    return ((x1 - x0) * (y2 - y1) - (y1 - y0) * (x2 - x1)) > 0.0


def isClockwise(points) -> bool:
    """Expects iterable of two-element-tuples.
    For example:
    points = ((0, 0), (1, 0), (1, 1), (0, 1), (0, 0))"""

    return __isClockwise(*points)


def isConcave(points) -> bool:
    """Expects iterable of two-element-tuples.
    For example:
    points = ((0, 0), (1, 0), (1, 1), (0, 1), (0, 0))"""

    (x0, y0), (x1, y1), (x2, y2), *_ = points
    switch = __isClockwise((x0, y0), (x1, y1), (x2, y2))
    for (xn, yn) in points[3:]:

        if switch != __isClockwise((x1, y1), (x2, y2), (xn, yn)):
            return True

        # Delayed for performance:
        ((x0, y0), (x1, y1), (x2, y2)) = ((x1, y1), (x2, y2), (xn, yn))

    return False
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Laksono, Fx Anjar Tri
AU  - Borzi, Laura
AU  - Distefano, Salvatore
AU  - Czirok, Lili
AU  - Halmai, Ákos
AU  - Di Stefano, Agata
AU  - Kovács, János
TI  - Shoreline change dynamics along the Augusta coast, eastern Sicily, South Italy
JF  - EARTH SURFACE PROCESSES AND LANDFORMS
J2  - EARTH SURF PROCESS LANDF
VL  - 48
PY  - 2023
IS  - 9
SP  - 1
EP  - 12
PG  - 12
SN  - 0197-9337
DO  - 10.1002/esp.5644
UR  - https://m2.mtmt.hu/api/publication/34034637
ID  - 34034637
N1  - Funding Agency and Grant Number: Uj Nemzeti Kivalosag Program (UNKP) [UNKP-22-3-1]
            Funding text: Uj Nemzeti Kivalosag Program (UNKP), Grant/Award Number: UNKP-22-3-1
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Lovász, Virág
AU  - Halász, Amadé
AU  - Molnár, Péter
AU  - Karsa, Róbert
AU  - Halmai, Ákos
TI  - Application of a CNN to the Boda Claystone Formation for high-level radioactive waste disposal
JF  - SCIENTIFIC REPORTS
J2  - SCI REP
VL  - 13
PY  - 2023
IS  - 1
PG  - 16
SN  - 2045-2322
DO  - 10.1038/s41598-023-31564-1
UR  - https://m2.mtmt.hu/api/publication/33733477
ID  - 33733477
N1  - Funding Agency and Grant Number: University of Pecs
            Funding text: The Public Limited Company for Radioactive Waste Management (PURAM) greatly assisted our work by providing us with core scanning logs, scanned cores, internal reports, and core documentation. Every figure and table presented in this article is based on PURAM data. We thank them for their support. We are grateful to Dr. Gyula Konrad for proofreading. We also thank Dr. Denes Loczy for improving the quality of our English translation. We thank the Doctoral School of Earth Sciences (University of Pecs) for providing the computational power necessary for the research. Open access funding was provided by the University of Pecs. Every figure was created in ArcGIS Pro (ver.: 2.8.4; Environmental System Research Inc., Redlands, CA, USA).Open access funding was provided by University of Pecs
AB  - Nations relying on nuclear power generation face great responsibilities when designing their firmly secured final repositories. In Hungary, the potential host rock [the Boda Claystone Formation (BCF)] of the deep geological repository is under extensive examination. To promote a deeper comprehension of potential radioactive isotope transport and ultimately synthesis for site evaluation purposes, we have efficiently tailored geospatial image processing using a convolutional neural network (CNN). We customized the CNN according to the intricate nature of the fracture geometries in the BCF, enabling the recognition process to be particularly sensitive to details and to interpret them in the correct tectonic context. Furthermore, we set the highest processing scale standards to measure the performance of our model, and the testing circumstances intentionally involved various technological and geological hindrances. Our presented model reached ~ 0.85 precision, ~ 0.89 recall, an ~ 0.87 F1 score, and a ~ 2° mean error regarding dip value extraction. With the combination of a CNN and geospatial methodology, we present the description, performance, and limits of a fully automated workflow for extracting BCF fractures and their dipping data from scanned cores.
LA  - English
DB  - MTMT
ER  - 

TY  - ART
AU  - Halmai, Ákos
TI  - SL3Reader
PY  - 2022
UR  - https://m2.mtmt.hu/api/publication/33741721
ID  - 33741721
AB  - It is a tiny C# app, which is able to read SL3 sonar log files made by Lowrance & Simard devices and export the frame headers into a CSV text file. For details see & cite the following publication: Halmai, Ákos; Gradwohl–Valkay, Alexandra; Czigány, Szabolcs; Ficsor, Johanna; Liptay, Zoltán Árpád; Kiss, Kinga; Lóczy, Dénes and Pirkhoffer, Ervin. 2020. "Applicability of a Recreational-Grade Interferometric Sonar for the Bathymetric Survey and Monitoring of the Drava River" ISPRS International Journal of Geo-Information 9, no. 3: 149. https://doi.org/10.3390/ijgi9030149 https://www.mdpi.com/2220-9964/9/3/149

For Hungarian readers: Halmai Ákos, Balatonyi László, Valkay Alexandra Ilona, Czigány Szabolcs, Liptay Zoltán Árpád, Pirkhoffer Ervin. 2018. Új megközelítésű mederfelmérési technikák alkalmazása kisvízfolyásokon. Védelem Tudomány – III. évfolyam 4. szám, 2018. 12. hó. http://www.vedelemtudomany.hu/articles/III/4/09-halmai-etal.pdf

Dissertation in Hungarian: https://pea.lib.pte.hu/handle/pea/24594
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Gyenizse, Péter
AU  - Soltész, Emese
AU  - Lóczy, Dénes
AU  - Kovács, János
AU  - Nagyváradi, László
AU  - Elekes, Tibor
AU  - Gyenizse-Nagy, Sára
AU  - Németh, Gergő
AU  - Halmai, Ákos
TI  - Light Pollution Mapping in Pecs City with the Help of SQM-L and VIIRS DNB. The Effect of Public Luminaire Replacements on the Sky Background of the Urban Sky
JF  - GEOGRAPHICA PANNONICA
J2  - GEOGRAPHICA PANNONICA
VL  - 26
PY  - 2022
IS  - 4
SP  - 334
EP  - 344
PG  - 11
SN  - 0354-8724
DO  - 10.5937/gp26-39526
UR  - https://m2.mtmt.hu/api/publication/33568387
ID  - 33568387
AB  - Recently light pollution has been one of the most dynamically increasing form of environmental pollution. Light, if it arrives at the wrong place, time, quantity and quality, is harmful to human health and the physical environment-not to mention that it is a mere waste of energy. The brightness of the sky above Pécs was measured by SQM-L instruments in 2011 and 2019. Maps of the different neighbourhoods with different levels of light pollution have been prepared. In addition, special VIIRS day/night band satellite images were also analysed using QGIS software. Our investigations coincided with the modernization of street lighting in the city. The impact of LED illuminators installed along main roads in Pécs was observed locally.
LA  - English
DB  - MTMT
ER  - 

TY  - CHAP
AU  - Laksono, Fx Anjar Tri
AU  - Czirok, Lili
AU  - Halmai, Ákos
AU  - Kovács, János
ED  - Hatvani, István Gábor
ED  - Erdélyi, Dániel
ED  - Fedor, Ferenc
TI  - Analysis of Coastline Change on the Eastern Coast of Sicily, Italy Based on the Calculation of End Point Rate and Linear Regression Rate Statistical Parameters
T2  - GeoMATES '22 International Congress on Geomathematics in Earth- and Environmental Sciences
PB  - MTA Pécsi Akadémiai Bizottság (MTA PAB)
CY  - Pécs
SN  - 9789637068140
PY  - 2022
SP  - 33
EP  - 33
PG  - 1
UR  - https://m2.mtmt.hu/api/publication/33560789
ID  - 33560789
AB  - The eastern coast of Sicily is prone to changes due to human activities, sea-level changes, marine
natural hazards, fluctuations in sediment supply, and uplift. This phenomenon will impact the
resilience of infrastructure and settlements in the area. Therefore, this study aims to analyze the
coastline changes of eastern Sicily over the last 50 decades with a case study of the Catania to
Syracuse provinces. The method applied in this study is the analysis of Landsat image from 1972 to
2021, which then calculates the statistical parameters of End Point Rate (EPR) and Linear Regression
Rate (LRR) using the Digital Shoreline Analysis System (DSAS) to obtain information on the average
of accretion and erosion rates. The study results demonstrate that the average accretion and
erosion rates on the eastern coast of Sicily are 1.39172 m/year and -0.85858 m/year. The highest
accretion and erosion rates reached 4.55 m/year and -8.99 m/year. This study concludes that the
eastern coast of Sicily changes towards the sea, or in other words, there is an expansion of the
coastal area.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Sarkadi, Noémi
AU  - Pirkhoffer, Ervin
AU  - Lóczy, Dénes
AU  - Balatonyi, László
AU  - Geresdi, István
AU  - Fábián, Szabolcs Ákos
AU  - Varga, Gábor
AU  - Balogh, Richárd
AU  - Gradwohl-Valkay, Alexandra Ilona
AU  - Halmai, Ákos
AU  - Czigány, Szabolcs
TI  - Generation of a flood susceptibility map of evenly weighted conditioning factors for Hungary
JF  - GEOGRAPHICA PANNONICA
J2  - GEOGRAPHICA PANNONICA
VL  - 26
PY  - 2022
IS  - 3
SP  - 200
EP  - 214
PG  - 15
SN  - 0354-8724
DO  - 10.5937/gp26-38969
UR  - https://m2.mtmt.hu/api/publication/33202808
ID  - 33202808
N1  - Institute of Geography and Earth Sciences, University of Pécs, Ifjúság u. 6, Pécs, 7624, Hungary            
            General Directorate of Water Management, Márvány utca 1/D, Budapest, 1012, Hungary            
            Cited By :1            
            Export Date: 9 October 2023            
            Correspondence Address: Pirkhoffer, E.; Institute of Geography and Earth Sciences, Ifjúság u. 6, Hungary; email: pirkhoff@gamma.ttk.pte.hu
AB  - Over the past decades, in the mountainous, hilly and/or urban areas of Hungary several high-intensity storms were followed by severe flash flooding and other hydrologic consequences. The overall aim of this paper was to upgrade the national flash flood susceptibility map of Hungary first published by Czigány et al. (2011). One elementary watershed level (FFSIws) and three settlement level flash flood susceptibility maps (FFSIs) were constructed using 13 environmental factors that influence flash flood generation. FFSI maps were verified by 2,677 documented flash flood events. In total, 5,458 watersheds were delineated. Almost exactly 10% of all delineated watersheds were included into the category of extreme susceptibility. While the number of the mean-based FFSIs demonstrated a normal quasi-Gaussian distribution with very low percentages in the quintile of low and extreme categories, the maximum-based FFSIs overemphasized the proportion of settlements of high and extreme susceptibility. These two categories combined accounted for more than 50% of all settlements. The highest accuracy at 59.02% for class 5 (highest susceptibility) was found for the majority based FFSIs. The current map has been improved compared to the former one in terms of (i) a higher number of conditional factors considered, (ii) higher resolution, (iii) being settlement-based and (iv) a higher number of events used for verification.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Ortmann-né Ajkai, Adrienne
AU  - Morva, Tamás
AU  - Pirkhoffer, Ervin
AU  - Lóczy, Dénes
AU  - Halmai, Ákos
AU  - Németh, Gergő
AU  - Gyenizse, Péter
TI  - A GIS-based framework to determine spatially explicit priority categories for flood risk management intervention schemes
JF  - MORAVIAN GEOGRAPHICAL REPORTS
J2  - MORAV GEOGR REP
VL  - 30
PY  - 2022
IS  - 3
SP  - 211
EP  - 226
PG  - 16
SN  - 1210-8812
DO  - 10.2478/mgr-2022-0014
UR  - https://m2.mtmt.hu/api/publication/33155083
ID  - 33155083
N1  - Funding Agency and Grant Number: National Research, Development and Innovation Office, Hungary (NKFIH) [SNN 125727]; Slovenian Research Agency (ARRS) [N6-0070]; research program Geography of Slovenia (ARRS) [P6-0101]; New National Excellence Program of the Ministry for Innovation and Technology [UNKP-21-3-I]
            Funding text: The authors express their gratitude to three anonymous reviewers, whose thorough work and useful questions helped to improve the manuscript to a great extent. We are grateful to the financial support from the National Research, Development and Innovation Office, Hungary (NKFIH) within the framework of the Hungarian-Slovenian collaborative project "Possible ecological control of flood hazard in the hill regions of Hungary and Slovenia" (contract no SNN 125727) and within the framework of the program Excellence in Higher Education, Theme II.3 ("Innovation for sustainable life and environment"). The authors acknowledge that the study was performed in the frame of the project "Possible ecological control of flood hazard in the hilly regions of Hungary and Slovenia". The project was financially supported by the Slovenian Research Agency (ARRS, N6-0070) and the research program Geography of Slovenia (ARRS, P6-0101). Furthermore, we are grateful to the South-Transdanubian Water Management Directorate (Hungary) for data provision and support. GN was financially supported by UNKP-21-3-I. ("New National Excellence Program of the Ministry for Innovation and Technology").
AB  - The necessity of plural valuation of costs for flood risk management is widely acknowledged, but practical case studies are still scarce. We developed a GIS-based plural valuation framework to determine spatially explicit priority categories for flood risk management intervention schemes on the Drava River, Southern Hungary. A conventional economic evaluation, including land market prices and additional costs due to legal conservation restrictions, was complemented by ecological valuation of vulnerability. The inclusion of ecological vulnerability significantly changed the proposed priority areas for flood risk management interventions: in this case, softwood riparian forests face far less threat, together with other Natura 2000 habitats, in comparison to unprotected wetlands and grasslands. This valuation framework also highlights priority habitats and areas for joint conservation and water management projects, utilising the synergies between several EU Directives as the Birds Directive, Habitats Directive, Flood Directive, and Water Framework Directive. Our framework is adaptable for the other floodplains along major or medium-sized European rivers, assuming that specific local settings are considered.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Víg, Balázs
AU  - Fábián, Szabolcs Ákos
AU  - Czigány, Szabolcs
AU  - Pirkhoffer, Ervin
AU  - Halmai, Ákos
AU  - Kovács, István Péter
AU  - Varga, Gábor
AU  - Dezső, József
AU  - Nagy, Gábor
AU  - Lóczy, Dénes
TI  - Morphometric analysis of low mountains for mapping flash flood susceptibility in headwaters
JF  - NATURAL HAZARDS
J2  - NAT HAZARDS
VL  - 114
PY  - 2022
IS  - 3
SP  - 3235
EP  - 3554
PG  - 20
SN  - 0921-030X
DO  - 10.1007/s11069-022-05513-6
UR  - https://m2.mtmt.hu/api/publication/33042768
ID  - 33042768
N1  - Doctoral School of Earth Sciences, Institute of Geography and Earth Sciences, University of Pécs, Pécs, Hungary            
            Institute of Geography and Earth Sciences, University of Pécs, Pécs, Hungary            
            South-Transdanubian Water Management Directorate, Pécs, Hungary            
            Cited By :1            
            Export Date: 9 October 2023            
            Correspondence Address: Víg, B.; Doctoral School of Earth Sciences, Hungary; email: vbalazs90@hotmail.com            
            Funding details: GINOP-2.3.2–15-2016–00055            
            Funding details: Emberi Eroforrások Minisztériuma, EMMI, 20765            
            Funding text 1: We sincerely thank the Editors and Reviewers for their useful and comprehensive comments on the manuscript, and we greatly appreciate their time and effort spent in this paper. The authors are also grateful to the Mecsek Forestry Co. Ltd (Mecsekerdő Zrt.) and the South-Transdanubian Water Management Directorate (Dél-Dunántúli Vízügyi Igazgatóság, DDVIZIG) for providing data for the current research.            
            Funding text 2: Open access funding provided by University of Pécs. This research was funded by the Higher Education Institutional Excellence Program of Ministry of Human Capacities (Hungary), Grant Number “20765–3/2018/FEKUTSTRAT” at the University of Pécs and the Hungarian National Office for Research and Innovation (project GINOP-2.3.2–15-2016–00055).
AB  - Morphometric indices from high-resolution DEMs can contribute to the estimation of flash flood susceptibility in mountainous areas. We have screened 25 morphometric indices commonly used in literature, and based on a correlation matrix, selected those which showed the strongest relationship with flash flood generation: area ( A ), drainage texture (Rt), drainage density (Dd), elongation ratio (Re), form factor (Ff), lemniscate method ( k ), Gravelius coefficient (GC), forested area (Fa) and relief ratio (Rr). Among them Dd, Rt and Rr had a direct impact on flash flood generation, while A , Re, Fa, Ff, k and GC are in inverse relationship with the intensity of flash floods. Our summary map shows the prioritization of the watersheds on a scale of 0 to 9. The flash flood susceptibility ranking was empirically verified using hydrological data (20-year water regime obtained from 14 official stream gauges). Our conclusions only partially agree with former observations which may be explained by the particular lithology and morphology of the Mecsek Mountains. Since the lower sections of the watersheds are urbanized, for optimal watershed management more detailed GIS analyses of anthropogenic controls on flash flood hazard are needed in the future.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Szabó, Péter
AU  - Kovács, János
AU  - Kocsis, L
AU  - Vennemann, T
AU  - Domingo, L
AU  - Újvári, Gábor
AU  - Halmai, Ákos
AU  - Pirkhoffer, Ervin
AU  - Codrea, V
TI  - Pliocene - Early Pleistocene continental climate and vegetation in Europe based on stable isotope compositions of mammal tooth enamel
JF  - QUATERNARY SCIENCE REVIEWS
J2  - QUATERN SCI REV
VL  - 288
PY  - 2022
PG  - 19
SN  - 0277-3791
DO  - 10.1016/j.quascirev.2022.107572
UR  - https://m2.mtmt.hu/api/publication/32861079
ID  - 32861079
AB  - There is an increasing need for paleoclimate records from continental settings to better understand the climatic changes during critical periods such as the Pliocene and Early Pleistocene. Present data indicates a transition from a warmer than present-day climate to a substantially different cooler climate. This study reviews the oxygen and carbon isotope compositions of mammalian tooth enamel for the Pliocene
and Early Pleistocene of South and Central Europe to reconstruct the spatial distribution and temporal changes of the vegetation and oxygen isotope composition of precipitation (d18Oppt). In addition to a literature review, this study adds new stable isotope measurements for this period. All d13C values indicate C3 ecosystems and reflect major changes in the water use efficiency and/or in the prevailing
humidity. The reconstructed major floral types range from woodland to woodland ‒ mesic grassland in all of the investigated regions. The carbon isotope compositions of fossil mammal teeth demonstrate that the spatial distribution of vegetation was broadly similar to those of the present-day for the Early/Late Pliocene e Early Pleistocene, with the most “closed” vegetation in Central and Northern Italy, while open mesic grassland vegetation covers can be reconstructed for the Iberian Peninsula, Massif Central region (Central France) and the Carpathian Basin. The calculated d18Oppt values give a negative temporal shift of about 1e1.5‰ from the Early Pliocene to Late Pliocene e Early Pleistocene in three regions (Iberian Peninsula, Central Italy, Carpathian Basin), potentially representing a 1.5e3.0 C decrease in mean annual
temperatures (MAT) over time. In the Massif Central region and the Carpathian Basin, the d18Oppt values are almost the same for the Late Pliocene and Early Pleistocene, while in Northern Italy the values decreased over that period. The d18Oppt values are in the range of present-day d18Oppt values over the Early Pliocene and somewhat lower than present-day values for the Late Pliocene - Early Pleistocene in
most of the regions. Because most other proxies indicate warmer than present-day climate for the Early Pliocene and similar to present-day climate for the Early Pleistocene, the d18Oppt values are generally lower than expected, which can be partially explained by local effects.
LA  - English
DB  - MTMT
ER  -