Search in Publications

Found 6278 publications

A coupled impact of different management and soil moisture on yield of winter wheat (Triticum aestivum L.) in dry conditions at locality Mezoföld, Hungary

G. Milics

Publication Name: Journal of Hydrology and Hydromechanics

Publication Date: 2021-03-01

Volume: 69

Issue: 1

Page Range: 76-86

Description:

Variable rate technology (VRT) in nutrient management has been developed in order to apply crop inputs according to the required amount of fertilizers. Meteorological conditions rarely differ within one field; however, differences in soil conditions responding to precipitation or evaporation results within field variations. These variations in soil properties such as moisture content, evapotranspiration ability, etc. requires site-specific treatments for the produced crops. There is an ongoing debate among experts on how to define management zones as well as how to define the required amount of fertilizers for phosphorus and nitrogen replenishment for winter wheat (Triticum aestivum L.) production. For management zone delineation, vegetation based or soil based data collection is applied, where various sensor technology or remote sensing is in help for the farmers. The objective of the study reported in this paper was to investigate the effect of soil moisture data derived from Sentinel-2 satellite images moisture index and variable rate phosphorus and nitrogen fertilizer by means of variable rate application (VRA) in winter wheat in Mezoföld, Hungary. Satellite based moisture index variance at the time of sowing has been derived, calculated and later used for data comparison. Data for selected points showed strong correlation (R2 = 0.8056; n = 6) between moisture index and yield, however generally for the whole field correlation does not appear. Vegetation monitoring has been carried out by means of NDVI data calculation. On the field level, as indicated earlier neither moisture index values at sowing nor vegetation index data was sufficient to determine yield. Winter wheat production based on VRA treatment resulted significant increase in harvested crop: 5.07 t/h in 2013 compared to 8.9 t/ha in 2018. Uniformly managed (control) areas provided similar yield as VRA treated areas (8.82 and 8.9 t/ha, respectively); however, the input fertilizer was reduced by 108 kg/ha N and increased by 37 kg/ha P.

Open Access: Yes

DOI: 10.2478/johh-2020-0039

Possibilities for Further Development of the Airbags in the Case of Non-conventional Seating Positions

István Lakatos Laszlo Porkolab

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2025-01-01

Volume: 53

Issue: 2

Page Range: 146-157

Description:

The first ideas and experiments aimed at protecting passengers from the vehicle’s internal components with airbags date back to the 1960s. Twenty years later, the airbag appeared in series production, in December 1980, the Mercedes-Benz S-Class (W126) was the first serial production car to be equipped with a driver airbag, and since its introduction, the use of airbag technology has been uninterrupted. Airbag systems are currently regarded as almost mandatory protection systems in a vehicle. The article generally presents the development of airbags used in cars, followed by the currently used airbag folding types. After that, the article presents the simulation of the airbag deployment, its types and theoretical background, as well as the most important stages of the deployment of the airbag. In the following, the article presents the results of the research so far in the case of frontal and side crashes. The next section of the article introduces the materials capable of absorbing energy, then details the simulation model built and the airbag concept created. The last part of the article contains an evaluation of the results and the summary. The modified seat examined in the earlier phase of the research and the airbag concept that is the subject of this research also fulfill the set goals, but the latter has a great advantage.

Open Access: Yes

DOI: 10.3311/PPtr.38633

TURNING THE TRIPLE BURDEN OF UKRAINIAN DEPOPULATION INTO A QUADRUPLE BURDEN: THE RESULTS OF A SURVEY AMONG UKRAINIAN REFUGEE WOMEN

Sándor Remsei Éva Berde

Publication Name: Economics and Sociology

Publication Date: 2025-01-01

Volume: 18

Issue: 1

Page Range: 296-312

Description:

The effects of the Russian-Ukrainian war on Ukraine's demographic landscape are immense. One key consideration is whether Ukrainian refugee women intend to return to their country after the war ends. If the return is planned, the question of whether they would wish to have children is also relevant. This study explored these issues by surveying women who fled to Hungary and the Netherlands. Among those surveyed, 42% did not plan to return under any circumstances, and only 12% intended to return even if their home area came under Russian control. Logistic regression was used to identify factors influencing the intention to return, with reluctance to have additional children and income earned through employment emerging as the strongest explanatory factors. However, we found only modest associations between the intention to return and other variables. Our findings suggest that deeply rooted personal preferences shape these women’s plans.

Open Access: Yes

DOI: 10.14254/2071-789X.2025/18-1/16

Sentiment and Deep Learning Analysis of Childbirth Experiences: Insights for Improving Maternity Care and Hospital Policies

Tao Zhang Ferenc Erdos Yanzhang Geng Peter Appiahene Vijayakumar Varadarajan Stephen Afrifa

Publication Name: Applied Computational Intelligence and Soft Computing

Publication Date: 2025-01-01

Volume: 2025

Issue: 1

Page Range: Unknown

Description:

Maternal childbirth experiences are crucial indicators of health care quality, patient satisfaction, and emotional health. The increasing use of social media platforms, such as Facebook, provides a unique opportunity to examine public sentiment and narratives around maternity care. However, limited studies have employed deep learning (DL)–based sentiment analysis (SA) to comprehensively analyze childbirth experiences in low-resource environments. This study utilizes a hybrid technique that integrates unsupervised topic modeling with supervised DL sentiment classification to capture both thematic breadth and emotional tone of birthing experiences. A dataset of Facebook comments was preprocessed and analyzed using word frequency analysis, latent Dirichlet allocation (LDA) for thematic extraction, sentiment classification using convolutional neural networks (CNNs), and robustly optimized BERT pretraining approach (RoBERTa). Statistical correlations between sentiment polarity and hospital service variables were examined using the chi-square test. The word frequency analysis revealed significant themes such as maternal care, labor and childbirth experiences, informal childbirth discussions, spiritual beliefs, and personal childbirth stories. SA found a majority positive sentiment (5106 instances) with widespread sentiments of trust and joy, although considerable occurrences of fear (1,851), sadness (1,564), and anger (1,114) indicated traumatic delivery experiences. The CNN model outperformed RoBERTa, which had an AUC of 0.9988 and an accuracy of 87%. Statistical study (chi-square test, p < 0.0001) showed a significant correlation between sentiment polarity and hospital service variables, indicating the influence of treatment quality on patient views. This study emphasizes the significance of SA in assessing maternal health care experiences and improving hospital practices. The findings highlight the need of increased communication, empathetic midwifery care, and patient-centered approaches in addressing unfavorable childbirth experiences. This study provides policymakers with data-driven insights to improve maternal health care policies, increase patient experiences, and ensure valuable maternity services.

Open Access: Yes

DOI: 10.1155/acis/8915424

Application of Bivariate Extreme Value models to describe the joint behavior of temporal and speed related surrogate measures of safety

Attila Borsos

Publication Name: Accident Analysis and Prevention

Publication Date: 2021-09-01

Volume: 159

Issue: Unknown

Page Range: Unknown

Description:

Limitations of historical crash data and the advantages of surrogate measures of safety have already been stressed by various authors. To describe nearness-to-collision, mostly time-based indicators are applied, and there is a consensus among researchers that speed-related indicators are needed to account for the severity dimension. There have been attempts to fit bivariate Extreme Value models to predict the number of crashes, however modeling crash frequency together with severity has received much less attention. The aim of this paper is to apply Extreme Value models to various pairs of temporal and speed-related indicators in order to investigate the dependence structure between them as well as to construct probability based risk levels and examine them in relation to severity levels. Bivariate threshold excess models were fitted to a dataset of left-turning and straight moving vehicle interactions recorded in a signalized intersection. The dependence structure between variable pairs were thoroughly investigated; it was concluded that temporal and speed related indicators were found independent, which means that road users getting close to each other in time does not necessarily come with high speeds. Therefore these indicators should be combined in order to properly predict severity; a temporal indicator on its own is not enough to make inferences about the severity of events. Using the calculated joint probability of events risk levels were constructed illustrating the events of equal probability.

Open Access: Yes

DOI: 10.1016/j.aap.2021.106274

FROM AI VIBRANCY TO LABOUR MARKET OUTCOMES: TESTING DISPLACEMENT ACROSS EDUCATION GROUPS

Aleksandra Kuzior Eszter Lukács Izabela Marszałek-Kotzur Khalima N. Sansyzbayeva Khalima N. Sansyzbayeva

Publication Name: Economics and Sociology

Publication Date: 2025-01-01

Volume: 18

Issue: 4

Page Range: 131-159

Description:

Artificial intelligence is expanding rapidly, intensifying policy concerns that more vibrant AI ecosystems may displace workers and increase unemployment. This study aims to test whether national AI vibrancy is associated with higher unemployment across education groups (advanced, intermediate and basic). Using an unbalanced panel of 34–35 countries from 2017 to 2023, the analysis combines Stanford’s AI Vibrancy Score with World Bank indicators and estimates two-way fixed-and random-effects models, employing Box–Cox/log transformations and dependence-robust inference (including country/time clustering and Driscoll–Kraay standard errors). The results provide little support for the displacement hypothesis. For advanced-education unemployment, AI vibrancy is statistically insignificant in the two-way FE model. It remains insignificant under all robust corrections (ln(AI vibrancy): β=−0.099, country-clustered p=0.494, time-clustered p=0.544, Driscoll–Kraay p=0.468). For basic-education unemployment, AI vibrancy is likewise insignificant in the two-way FE model (p=0.782). It remains insignificant under country clustering (p=0.830), time clustering (p=0.813) and Driscoll–Kraay inference (p=0.819). For intermediate-education unemployment, the AI coefficient remains insignificant under country clustering (p=0.273), time clustering (p=0.310), and Driscoll–Kraay corrections (p=0.226), indicating no robust unemployment-increasing effect across education groups during the observed period.

Open Access: Yes

DOI: 10.14254/2071-789X.2025/18-4/7

Analysis of socio-economic spatial structure of urban agglomeration in China based on spatial gradient and clustering

Laszlo Vasa Jian'ge Tao Ping Meng Meng Yan Dan Chen Li He

Publication Name: Oeconomia Copernicana

Publication Date: 2021-09-01

Volume: 12

Issue: 3

Page Range: 789-819

Description:

Research background: Previous studies on the economic and social development of urban agglomerations mostly focus on a single primacy comparative analysis and efficiency evaluation. Spatial structure differentiation is an important feature of urban agglomeration. The lack of economic and social analysis on the spatial structure makes it impossible to determine the development positioning of each city in the urban agglomeration, which affects the sustainable economic devel-opment ability of these areas. Purpose of the article: The objective of the article is to analyze the spatial development law and experience of urban agglomeration, this study explores the practice of economic and population spatial structure of city areas in China. For this purpose, CPUA and its central city Zhengzhou was taken as an example, the spatial gradient structure of example was analyzed. Methods: Using economic and population data of 32 cities in this region, growth pole theory, and pole-axis theory, the economic and population spatial structure of urban agglomeration, the spatial gradient structure of central cities in urban agglomerations were analyzed with the method of cluster about radiation index. Findings & value added: (1) In the process of the formation of CPUA, the geo-graphical spatial pattern plays a decisive role in economic and social development. This is an experience from developing countries. (2) CPUA presents a gradient development pattern with Zhengzhou as the center, and economic and social development gradually radiates to the metropolitan area, the core development area, and the character development demonstration area. (3) The economic and social gradients of Zhengzhou, the central city, present the hierarchy rules and characteristics which are driven by the Beijing-Guangzhou-Railway axis and the Longhai-Railway axis. (4) The central city of Zhengzhou still presents insufficient primacy in regional development, which shows that Zhengzhou accounts for 6% of the population of the Central Plains Economic Zone and 14% of GDP, and insufficient agglomeration. Different countries at different stages of economic development have different urban agglomeration development models. The conclusions from China provide new decision-making ideas and methods for spatial structure research and development strategy analysis of urban agglomerations.

Open Access: Yes

DOI: 10.24136/OC.2021.026

Integral operators in relation to the HOSVD-based canonical form

András Rövid Peter Varlaki Lászlõ Szeidl

Publication Name: Asian Journal of Control

Publication Date: 2015-03-01

Volume: 17

Issue: 2

Page Range: 459-466

Description:

This paper describes the relation of the higher order singular value decomposition (HOSVD) based canonical form to the Hilbert-Schmidt type integral operators. This connection between the canonical form of f(x) and the integral operators determined by function f(x) is important; on the one hand it gives a new aspect for the consideration of LPV models, and on the other hand it allows for the approximation of eigenfunctions and integral operators based on a numerical reconstruction of the canonical form.

Open Access: Yes

DOI: 10.1002/asjc.1017

Range sensor-based occupancy grid mapping with signatures

Áron Ballagi Csaba Hajdu Ernö Horváth Claudiu Radu

Publication Name: Proceedings of the 2019 20th International Carpathian Control Conference Iccc 2019

Publication Date: 2019-05-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Recently autonomous navigation technologies have received huge attention in many fields, such as autonomous driving or mobile robotics. Simultaneous localization and mapping (SLAM) [1] is a key problem in this field and the current paper targets the mapping part of it. Mapping means to construct accurate static or even dynamic representation of the observable environment. There are of course solutions for range sensor-based mapping, but the current paper proposes a new approach, which involves signatures. Signature is a mathematical data representation, which handles well uncertainty in complex systems.

Open Access: Yes

DOI: 10.1109/CarpathianCC.2019.8765684