Search in Publications

Found 6273 publications

The impact of covid-19 on the economy and sustainable e-commerce

Laszlo Vasa Judit Oláh Nicodemus M. Kitukutha

Publication Name: Forum Scientiae Oeconomia

Publication Date: 2021-01-01

Volume: 9

Issue: 2

Page Range: 47-72

Description:

This study aims to examine the impact of COVID-19 and sustainable e-commerce in Hungary and Kenya. COVID-19 has devastated the global economy, resulting in financial and job losses. Routine changes in spending have moved the focus from non-essential to essential items, due to the impact of COVID-19, the associated economic meltdown, and the deterioration of people’s physical and mental health. However, e-commerce can be a better option to stop the spread of COVID-19 due to its real benefits and usefulness in solving the challenges faced. The methodology used in this paper is the collection of primary data from an online survey questionnaire, and secondary data from several databases,e.g.,the World Health Organisation (WHO) and Johns Hop-kins Centre websites. The results show the negative impact of COVID-19 on society and the economy, as well as the positive and significant effects ofthe growth of e-commerce during COVID-19, where most of the goods being purchased are medical supplies: masks, medicines, and food. This has been made possibleby the rise of e-commerce platforms as a link in sustainable e-commerce after the significant disruption to the worldwide supply chain due to total lockdown. E-commerce has shown growth during the COVID-19 pandemic period as a sustainable platform. In conclusion, this study proposes policies that support e-commerce in developing countries during and after COVID-19. Furthermore, theoretical, and managerial implications are proposed in the study. It is high time to warn businesses to adopt information and communications technology (ICT) to flourish and thrive during times of financial and economic hardship, such as the use of e-commerce with the right policies enacted to support sustainable e-commerce.

Open Access: Yes

DOI: 10.23762/FSO_VOL9_NO2_3

Energy Integration of Vertical Farms for Higher Efficiency and Sustainability

Jean Pimentel Ferenc Pongrácz György Ágoston Zoltán Sejpes Zsolt Bukodi István Kenyeres Ferenc Friedler

Publication Name: Chemical Engineering Transactions

Publication Date: 2021-01-01

Volume: 88

Issue: Unknown

Page Range: 727-732

Description:

As a result of the increasing human population, the availability of resources per capita has been vastly diminished in the last decades. Naturally, the depletion of valuable environmental assets such as water and arable land, poses a threat to mankind’s sustainable development. In this regard, various novel ideas have been proposed for processing agricultural products ecologically and sustainably; one of such ideas is vertical farming (VF). VF is a novel production technology that aims at enhancing both the yield and the product quality, by growing them in highly packed, high energy-density systems with high mass-flow rates and in a controlled environment. The technologies required for VF have been developed and successfully tested, thereby producing crops that meet the requirements of food safety, adequate nutrient content, and maximum yield. However, the extremely high biomass densities and high turnover rates employed to give rise to challenges regarding to energy efficiency and homogeneity patterns. In this work, a P-graph model is presented for the integration of VF systems. The algorithmic approach is employed to evaluate options for process integration and intensification of VF with plausible synergetic production processes into a dense urban environment. As a result, 115 integrated process alternatives are identified for the base case, with the best structure exhibiting a total cost of 41,920 EUR/y, thereby yielding reductions up to 11% for the total cost of the integrated network. The pareto front of economic performance and CO2 emission is presented to illustrate the potential benefits of integration, and the capability of the methodology to evaluate alternative designs.

Open Access: Yes

DOI: 10.3303/CET2188121

Experimental and Statistical Analysis of the Vertical Temperature Gradient, for Ballastless Railway Track, in Alpine and Plateau Environs

Szabolcs Fischer Xingwang Sheng Weiqi Zheng Tao Shi Chuanshu Li Ping Lou

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2023-01-01

Volume: 20

Issue: 1

Page Range: 123-142

Description:

Temporal temperature evolution of ballastless railway track is a random process caused by complex environmental actions. The vertical temperature gradient (VTG), varying continuously with time, has significant effects on the repeated deformation of ballastless track. However, few researchers have considered the statistical analysis of VTGs in alpine and plateau environs characterized by high altitude, strong solar radiation and high diurnal temperature differences. In this study, a temperature field test platform of ballastless track was established in Shannan City, Tibet and the temperature field of ballastless track was measured. Based on four statistical methods, a Monte Carlo simulation (MCS), Gaussian mixture model (GMM), Generalized Pareto distribution (GPD) and a third-order polynomial normal transformation technique (TPNT), the VTGs of ballastless track in alpine and plateau areas, are statistically analyzed. The results show that the applied statistical methods, used for predicting the VTG representative value, in ballastless track, are feasible within different application conditions. The recommended positive and negative representative values of the VTG of ballastless track are 91.58oC/m and-40.15oC/m, and 82.83oC/m and-35.03oC/m, with failure probabilities of 1% and 5% respectively, in alpine and plateau areas. The research results can provide a reference for the design and maintenance of ballastless track used in alpine and plateau environs.

Open Access: Yes

DOI: 10.12700/APH.20.1.2023.20.9

Preface

Robert Fullér Francesco Masulli Silvio Giove

Publication Name: Lecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics

Publication Date: 2019-01-01

Volume: 11291 LNAI

Issue: Unknown

Page Range: V

Description:

No description provided

Open Access: Yes

DOI: DOI not available

Ecotoxicological investigations of milking cow slurry and changes of oestrogenic compounds in the solid and liquid phase

Pál Szakál Judit Plutzer Richárd Gubó Ildikó Kiss-Szarvák Eduard Gubó Mishele Erdenebaatar Bence Horváth

Publication Name: Energy Ecology and Environment

Publication Date: 2022-04-01

Volume: 7

Issue: 2

Page Range: 97-110

Description:

Due to the appearance of intensive livestock-rearing systems since the 1970s, a vast amount of liquid manure (slurry) has been produced. The application and utilization are partly regulated for this special substance, which contains urine, excrement, process water, and other chemicals, such as insecticides and disinfectants. Our research was conducted on a slurry management system of a dairy cattle farm, focusing on the investigation of the presence of oestrogenic substances and toxicity of slurry before and after using a separator technology. Yeast oestrogen screen shows in this study that the separation of the liquid and solid phases of slurry contributes to the reduction in oestrogenic substances. Based on the toxicological studies, the growth inhibition of algae was 93%, and the inhibition of the germination of higher plant seeds was 25%, without separation. After separation of the phases, growth and germination were comparable with the negative control; moreover, some stimulation was detected. Consequently, harmful substances were removed with the suspended solid phase. From the present study, we can conclude that stakeholders should support separation technology in intensive livestock-rearing systems, and ecotoxicological investigations obviously help the risk management of slurry utilization. To our best knowledge, this is the first paper presenting detailed and complex toxicological study on slurry samples.

Open Access: Yes

DOI: 10.1007/s40974-021-00234-1

Heat Integrated Water Regeneration Network Synthesis via Graph-Theoretic Sequential Method

Ákos Orosz Bing Shen How Sin Yong Teng Juin Yau Lim Ferenc Friedler

Publication Name: Chemical Engineering Transactions

Publication Date: 2021-01-01

Volume: 88

Issue: Unknown

Page Range: 49-54

Description:

The integration of multiple resources conservation networks is necessary to attain the ever-stringent sustainable goals. This work takes initiatives to develop a heat integrated water network via a proposed P-graph-based sequential methodology. In the first step, a set of feasible water regeneration networks is generated using the conventional P-graph framework. Then, the obtained feasible networks will be used as the inputs in the second stage which aims to generate various sets of feasible heat exchanger networks. It is worth noting that the second model is solved by an extended P-graph framework (P-HENS) for combinatorial process network optimization. The solutions are then ranked based on the total network cost. To demonstrate the effectiveness of the proposed method, a typical water regeneration network (three sources and three sinks) with multi-contaminants is used. The results show a total of 103 feasible water network structures (water network cost ranging from 0.76 M$/y to 1.18 M$/y). Thereafter, a list of feasible HIWRN can be determined using P-HENS. The top four HIWRNs which offer similar total network cost (~1.639 M$/y) are demonstrated. This proposed method provides valuable insights that allow decision-makers to further select the optimal solution which may be more beneficial as compared to the one obtained via conventional methods.

Open Access: Yes

DOI: 10.3303/CET2188008

One succeeds and the other fails? Criminal justice in times of emergency

Peter Vaczi

Publication Name: Frontiers in Political Science

Publication Date: 2025-01-01

Volume: 7

Issue: Unknown

Page Range: Unknown

Description:

The Government has declared a state of emergency for the whole territory of Hungary for a period of 210 days from 1 November 2022 in view of the armed conflict and humanitarian disaster in Ukraine and to avert and manage the consequences of such conflicts in Hungary. Under the rules of emergency legislation, the Government is thus once again in a constitutional position to suspend the application of certain laws, derogate from statutory provisions and take other extraordinary measures. On the basis of this authorization, Government Decree 3/2023 (I. 12.) on the different application of certain provisions concerning the execution of sentences during a state of emergency was adopted at the beginning of the year, according to which, upon the request of a non-Hungarian convict, the national commander of the penitentiary system shall suspend the execution of the sentence until the transfer of the sentence, provided that certain conditions are met and there are no grounds for exclusion. Based on a detailed analysis of the legislation, it can be concluded that in practice this may also mean the remission of the remaining part of the sentence, since the receiving foreign state must ensure the enforcement of the sentence under Hungarian rules, but it is questionable whether this will be done. This outcome, however, runs counter to the fundamental principle of criminal justice, the principle of proportionate punishment, as it discriminates between offenders based on nationality. How compatible is this solution with the fundamental principles of the rule of law, such as non-discrimination or the principle of the obligation to be punished?

Open Access: Yes

DOI: 10.3389/fpos.2025.1511739

Function approximation capability of a novel fuzzy flip-flop based Neural Network

László Gál Rita Lovassy László T. Kóczy

Publication Name: Proceedings of the International Joint Conference on Neural Networks

Publication Date: 2009-11-18

Volume: Unknown

Issue: Unknown

Page Range: 1900-1907

Description:

The function approximation capability of various connectionist systems has been one of the most interesting problems. A method for constructing Multilayer Perceptron Neural Networks (MLP NN) with the aid of fuzzy operations based flip-flops able to approximate single and multiple variable functions is proposed. This paper introduces the concept of fuzzy flip-flop based neural network, particularly by deploying three types of fuzzy flip-flops as neurons. A comparative study of feedbacked fuzzy J-K and two kinds of fuzzy D flip-flops used as neurons, based on fuzzy algebraic, Yager, Dombi, Hamacher and Frank operations is given. Simulation results are presented for several test functions. © 2009 IEEE.

Open Access: Yes

DOI: 10.1109/IJCNN.2009.5178849

Modeling laterally loaded piles

János Szép

Publication Name: Pollack Periodica

Publication Date: 2013-08-01

Volume: 8

Issue: 2

Page Range: 117-129

Description:

Single row pile groups are gaining popularity as foundation system for both buildings and bridges. They are a reasonable and economical solutions for structures with low vertical loads e.g. bridge abutments. The lateral resistance of a pile group is the result of contact pressure between the individual pile shafts and the soil. When designing this kind of structure, the estimation of displacements and bending moments is the main focus of the calculation. In most cases single piles are modeled by assuming a Winkler material. For their calculations, designers typically employ one of the commonly-used structural FEM codes (e.g. AxisVM, Fem-Design). On the other hand, advanced, truly 3D FEM packages (like MIDAS GTS, Plaxis 3D) are available, allowing for realistic modeling of the soil environment and soil-structure interaction. As an intermediate solution, packages based on traditional approaches are also available (GEO5, CGU). In this paper, results obtained using three different calculation methods and packages are compared.

Open Access: Yes

DOI: 10.1556/Pollack.8.2013.2.13