Search in Publications

Found 6289 publications

Comparison of optimized PID and fuzzy control strategies on a mobile pendulum robot

Akos Odry Robert Fuller

Publication Name: Saci 2018 IEEE 12th International Symposium on Applied Computational Intelligence and Informatics Proceedings

Publication Date: 2018-08-20

Volume: Unknown

Issue: Unknown

Page Range: 207-212

Description:

S-This paper investigates the optimized control performances of fuzzy and proportional-integral-derivative (PID) control schemes developed for the stabilization of an under-actuated mobile robot. The fuzzy control strategy had been designed in an earlier paper, its equivalent PID controller-based scheme is established first. Then a complex cost function is defined that evaluates the reference tracking performance, the efficiency of system oscillations suppression and the average current consumption in the motor drive system. The particle swarm optimization (PSO) is applied to tune both control schemes under the same circumstances by minimizing the formulated cost function. Results demonstrate that the optimized fuzzy control strategy provides the same reference tracking quality with significantly better suppression of system oscillations and current peaks compared to the optimized PID control.

Open Access: Yes

DOI: 10.1109/SACI.2018.8440947

When herbicides don't really matter: Weed species composition of oil pumpkin (Cucurbita pepo L.) fields in Hungary

B. Czúcz P. Karácsony Gyula Pinke Z. Botta-Dukát

Publication Name: Crop Protection

Publication Date: 2018-08-01

Volume: 110

Issue: Unknown

Page Range: 236-244

Description:

Oil pumpkin is a major emerging alternative crop with several unresolved weed management questions in central-eastern Europe, one of the focal regions of oil pumpkin production worldwide. This study aims to assess the importance of three groups of factors: environment, non-chemical management (all management excluding herbicides), and chemical weed management, in determining the weed species composition of oil pumpkin crops in Hungary. We surveyed the weed flora of 180 oil pumpkin fields across the country, along with 32 background variables. Applying a minimal adequate model consisting of 18 terms with significant net effects, 30.8% of the total variation in weed species data could be explained. Most variation in species composition was determined by environmental factors, with climatic conditions (precipitation and temperature) being most influential. The net effects of seven non-chemical management variables (preceding crop, N and P fertilisers, seeding rate, crop cover, cultivating tillage, and manual weed control), and two herbicides (S-metolachlor and linuron) were also significant. Variation partitioning demonstrated the dominance of environmental factors, and it also showed that non-chemical management practices accounted for five times more variance than herbicides. Within non-chemical management, the relative impact of cultural variables was nearly five times larger than that of mechanical weed management. Among the abundant weeds, Chenopodium polyspermum and Ambrosia artemisiifolia were positively associated with precipitation, Datura stramonium and Hibiscus trionum correlated with higher temperature, and Chenopodium album favoured larger potassium content of the soil. High seeding rate and crop cover suppressed Amaranthus retroflexus, cultivating tillage reduced Ambrosia artemisiifolia and Setaria pumila, while conspicuous tall weeds like Abutilon theophrasti and Chenopodium album were most vulnerable to manual weed control. Although the short stature of pumpkin with its poor weed-suppressive ability could unfavourably influence the results of some cultural practices, our findings suggest that the weed vegetation of oil pumpkin fields can be efficiently managed also with environmentally benign methods.

Open Access: Yes

DOI: 10.1016/j.cropro.2017.06.018

Investigation of glued insulated rail joints with special fiber-glass reinforced synthetic fishplates using in continuously welded tracks

Szabolcs Fischer Attila Németh

Publication Name: Pollack Periodica

Publication Date: 2018-08-01

Volume: 13

Issue: 2

Page Range: 77-86

Description:

In this paper the authors partially summarize the results of a research on glued insulated rail joints with fiber-glass reinforced plastic fishplates (brand: Apatech) related to own executed laboratory tests. The goal of the research is to investigate the application of this new type of glued insulated rail joint where the fishplates are manufactured at high pressure, regulated temperature, glass-fiber reinforced polymer composite plastic material. The usage of this kind of glued insulated rail joints is able to eliminate the electric fishplate circuit and early fatigue deflection and it can ensure the isolation of rails' ends from each other by aspect of electric conductivity.

Open Access: Yes

DOI: 10.1556/606.2018.13.2.8

Numerical analysis of eddy current field in laminated media

Miklós Kuczmann

Publication Name: Pollack Periodica

Publication Date: 2018-08-01

Volume: 13

Issue: 2

Page Range: 3-14

Description:

A comprehensive analysis of the finite element method based lamination modeling has been performed and the results are presented in this paper. The simulations are made in two subsequent steps. In the first step, the approximate magnetic field distribution inside the material with linear characteristics is determined assuming a bulk material having anisotropic conductivity and laminates are not taken into account. In the second step, the eddy current field inside the individual laminates is modeled. The boundary conditions of any individual sheets are obtained from the bulk model. The paper presents the advantages and the drawbacks of the applicable potential formulations. Results are compared with the quasi-static electromagnetic field obtained from a reference solution taking account of each laminate.

Open Access: Yes

DOI: 10.1556/606.2018.13.2.1

Mapping the post-communist class structure findings from a new multidimensional Hungarian class survey

Fruzsina Albert Péter Róbert Zoltán Kmetty Luca Kristóf Andrea Szabó Beáta Dávid

Publication Name: East European Politics and Societies

Publication Date: 2018-08-01

Volume: 32

Issue: 3

Page Range: 544-565

Description:

In this article, we define a schema for the class structure of Hungary, in which we consider a case for an Eastern-European capitalist system emerging from post-communist societies. Our schema is based on the findings of the Hungarian Class Survey, 2014. Using six measures of Bourdieusian economic, cultural, and social capital and applying the methodology of latent class analysis (LCA), we have constructed a model of eight LCA-based classes: upper class, cultural middle class, affluent middle class, young urban consumers, network-embedded rural workers, young drifters, middle-aged deprived, and the precariat. Hungarian society seems to be quite hierarchical but is also fragmented within the upper and lower strata. Status inconsistency in terms of possessing economic, cultural, and social capital is strongly present even for the middle classes. There is a clear divide in our class model between the upper four and the lower four classes, in terms of vertical and nonvertical aspects of social stratification. We also compare our new multidimensional class typology to the traditional occupation-based one and demonstrate its added value for class analysis in Hungary.

Open Access: Yes

DOI: 10.1177/0888325417739954

The correspondences between formwork geometry and concrete composition in the case of fair-faced concrete elements

Kitti Karolyfi Ferenc Papp

Publication Name: Pollack Periodica

Publication Date: 2018-08-01

Volume: 13

Issue: 2

Page Range: 43-54

Description:

Modern architecture is unimaginable without fair-faced concrete. However, there is no generally accepted method for design the suitable concrete composition to get the required surface quality. This paper presents the effect of saturation degree on fair-faced concrete surfaces and raises additional research areas with regard to the formwork geometry and packing density of aggregate. This study is the first part of a wider research that aims to work out a method for determination of the adequate saturation degree of cement paste depending on the geometrical proportions of the formwork to reach the highest surface quality.

Open Access: Yes

DOI: 10.1556/606.2018.13.2.5

Measuring and simulating magnetic characteristics using Epstein frame

Miklós Kuczmann Zoltan Nemeth

Publication Name: Pollack Periodica

Publication Date: 2018-08-01

Volume: 13

Issue: 2

Page Range: 15-26

Description:

The paper discusses the standard of the Epstein frame that has been used to measure magnetic characteristics of the core made of material M250-35A supplied by different frequencies between 1-400 Hz. The measuring program has been built in LabVIEW including a control, filter and data save section as well. COMSOL Multiphysics 4.3b has been chosen as simulation environment, in which the Jiles-Atherton hysteresis model has been implemented.

Open Access: Yes

DOI: 10.1556/606.2018.13.2.2

Environmental activities of agricultural enterprises: Accounting and analytical support

Laszlo Vasa Nataliya Zdyrko Inna Lepetan Olesya Tomchuk

Publication Name: Economic Annals Xxi

Publication Date: 2018-07-19

Volume: 169

Issue: 1-2

Page Range: 77-83

Description:

The article outlines the causes of the ecological crisis in Ukraine and various factors affecting the natural environment, such as air pollution, depletion and degradation of land resources, exhaustion of forest and water resources, caused by agricultural production. Thus, in Ukraine, as of 1 January 2018, more than 1.1 million hectares of degraded, unproductive and technogenically contaminated lands counted to expand, and there were 315.6 thousand hectares of unproductive lands that needed improvement; 57% of the territory of the country was affected by wind and water erosion, about 12% were flooded lands and 20% more - polluted lands. The authors detail the consequences of the impact of agricultural activities on the environment. It is necessary to reflect environmental activities in accounting, including environmental assets (natural resource potential, production waste, non-current assets of environmental protection purposes), liabilities (environmental liabilities) and results of activities (environmental incomes, environmental expenses, financial results from environmental activities). The components of natural resource potential, which are to be reflected in the accounting system, are determined. The authors of the research provide an analytical estimation of the state, structure and changes of land resources in Ukraine and define the degree of compatibility between the modern system of agriculture and new environmental and technological requirements. The article discusses normative and legal provisions concerning land protection in Ukraine, as well as normative legal acts on ecologisation of agriculture. The tendency of the recent years shows that the mechanism of combining measures of financial incentives and legal responsibility in the field of land protection, as well as the establishment of legally determined environmental restrictions in land use by means of land management, remains insufficient in terms of optimising the use and protection of land in Ukraine. The study covers the main problem aspects of the land use in Ukraine. Analytical data describing the anti-desertification measures planned until 2030, as well as measures for the restoration of degraded lands and soils, including lands affected by desertification, droughts and floods, are presented. The need to reflect the costs of implementing measures to protect and restore the natural resource potential (including land resources) is emphasised. The authors generalise the information on three groups of accounting objects in terms of the use of agricultural land: objects affecting the qualitative condition (natural fertility) of land, objects representing land capital with a certain level of natural fertility which are at the disposal of enterprises, and objects that depend on the type of agricultural lands and their natural fertility. It is suggested to generalise the information on the objects of ecological accounting in the form of the Environmental Activity Report, which will increase the effectiveness of the managerial decisions on the environment at micro- and macro-levels.

Open Access: Yes

DOI: 10.21003/ea.V169-15

FEEL++ applications to engineering problems

Lotfi Abdelhakim

Publication Name: Aip Conference Proceedings

Publication Date: 2018-07-10

Volume: 1978

Issue: Unknown

Page Range: Unknown

Description:

Feel++ is a unified C++ implementation of Galerkin methods (finite and spectral element methods) in 1D, 2D and 3D to solve partial differential equations and provide a set of complementary modeling tools that can be applied to a large range of monophysics or multiphysics applications in fluid mechanics, solid mechanics, heat transfer, blood rheology, eye modeling and simulation and electro-magnetism. The software follows closely the mathematical abstractions associated with partial differential equations (PDE) and in particular the finite element mathematical framework and variational formulations. The Feel++ library offers solving strategies that scales up to thousands and even tens of thousands of cores and allows the developers to create C++ complex and typically non-linear multi-physics applications currently in industry, physics and health-care with powerful tools such as BOOST, PETSC or SLEPC which enable a huge backend for huge memory needs or enormous mathematical calculations.

Open Access: Yes

DOI: 10.1063/1.5044138