Search in Publications

Found 6289 publications

Detecting contours of pathological forms in colonoscopy images using a hybrid method

Plamen Petrov Veska Georgieva Brigita Sziová Szilvia Nagy

Publication Name: Communication Electromagnetics and Medical Application

Publication Date: 2018-01-01

Volume: 2018-October

Issue: Unknown

Page Range: 27-30

Description:

As colonoscopy is needed for screening colorectal polyps, and the first step of classification these polyps is recognizing them, it is worth to research, whether the colonoscopy databases could be improved by image processing and contour detection. In the following considerations a reflection filtering and background subtraction with large-sized mean filter is used as image preprocessing tools, and hybrid method for segmentation of pathological forms, based on template matching and active contour model as contour fitting for segmentation of the image is made.

Open Access: Yes

DOI: DOI not available

An S-graph based approach for multi-mode resource-constrained project scheduling with time-varying resource capacities

Máté Hegyháti O. Ooz

Publication Name: Chemical Engineering Transactions

Publication Date: 2018-01-01

Volume: 70

Issue: Unknown

Page Range: 1165-1170

Description:

The Resource-Constrained Project Scheduling Problem (RCPSP) is a general problem class of scheduling problems. It even contains the well-known job shop scheduling problem as a special case. In these problems, jobs demand different amounts from multiple resources at once. The goal is to minimize completion time while satisfying resource capacity constraints throughout the schedule. The RCPSP has several variations and generalizations, one of which is the multi-mode problem. Multiple operation modes are given for jobs, differing in resource usages and execution times. Another generalization is where resources have time-varying capacities instead of a constant limit. The S-graph framework was developed for batch process scheduling and used successfully in various applications. The advantages of this approach motivate research to extend its capabilities to more general problem classes and apply it in various specialized case studies. The authors have previously presented an extension of the S-graph framework for RCPSP and its multi-mode generalization. In this work, a further extension is proposed for handling time-varying capacities. The method relies on a model transformation technique and recent algorithmic developments of the framework.

Open Access: Yes

DOI: 10.3303/CET1870195

An S-graph based approach for multi-mode resource-constrained project scheduling with time-varying resource capacities

Máté Hegyháti O. Ooz

Publication Name: 23rd International Congress of Chemical and Process Engineering Chisa 2018 and 21st Conference on Process Integration Modelling and Optimisation for Energy Saving and Pollution Reduction Pres 2018

Publication Date: 2018-01-01

Volume: 2

Issue: Unknown

Page Range: 955

Description:

No description provided

Open Access: Yes

DOI: DOI not available

Development of a sustainable optimization model for the rehabilitation of transport infrastructure

András Bakó László Gáspár

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2018-01-01

Volume: 15

Issue: 1

Page Range: 11-33

Description:

About twenty years ago, the research activities aiming at the development of the optimal maintenance and rehabilitation strategies (models) of roads and bridges started in several countries, including Hungary. In the first foreign models, the deterioration depending on time and other parameters was given by Markov transition probability matrices. Due to the inaccuracies and inconsistencies of earlier models, a continuous model upgrading could have been carried out by many researchers world-wide. Besides, basically new models appeared in the literature, which are able to describe the actual processes more reliably. The research work of the authors of the paper has concentrated on Pavement Management Systems (PMSs) and Bridge Management Systems (BMSs). Since a common financing of roads and bridges is typical, a combined model of road pavement and bridge managements was developed by the authors increasing considerably the efficient use of available funds.

Open Access: Yes

DOI: 10.12700/APH.15.1.2018.1.2

Economic development and economic governance through the example of the city of Gyor

Dávid Fekete

Publication Name: Deturope

Publication Date: 2018-01-01

Volume: 10

Issue: 1

Page Range: 97-115

Description:

Since the 1990s the metropolitan region and its governance has got into the focus of regional science again. Nowadays a newer wave of metropolitan governance is authoritative, which has exceeded the former administrative-territorial planning aspects, and has appeared on the scene as the mechanism of economic development policy. Examining the development stages of regional policy it is well-known that the classical (modern) approach was superseded by the postmodern one. While the national methods applied in the classical period were characterized by strictness, central regulation, indirect regulation of the market (Fordist approach), in the postmodern period flexibility, decentralization and direct regulation have come to the fore (Post-Fordism). In the postmodern period the state level also takes its role in the financing of innovation and research and and development, and the notions of networking and competitiveness are coming more and more to the fore. In this article I analyze these processes through the case study of Gyor. After the theoretical introduction I examine the tools of economic development and economic governance in the Gyor metropolitan region. Activities observed in Gyor can strengthen the view-point that the processes of economic development and economic governance have nowadays been going on in parallel with each other. Moreover, the coordinating activities of local authorities can be observed in the work of organizations that support economic governance. In the course of the research it was also confirmed that built infrastructure can serve as a fundamental condition for the cooperation of network-systems that operate the governance system of a municipality.

Open Access: Yes

DOI: 10.32725/det.2018.006

Structure Selection and LPV Model Identification of a Car Steering Dynamics⁎

Gabor Rodonyi Zoltán Szabó Péter Korös Dániel Pup Alexandros Soumelidis József Bokor

Publication Name: Unknown

Publication Date: 2018-01-01

Volume: 51

Issue: 15

Page Range: 1086-1091

Description:

A Linear Parameter-Varying (LPV), discrete-time black box model of an electric power assisted steering system of a passenger car is identified from open-loop step response measurement data. The goal is to provide a nominal model for control design and analysis that is able to describe the principal characteristics of the system in the whole region of steering angle and speed range of 3 to 30 km/h. Examining a set of experimental data by using classical linear time-invariant black box modeling and validation techniques, the structure of the LPV model is determined. The parameters of the model are identified based on minimizing a quadratic error criterion by nonlinear optimization algorithms.

Open Access: Yes

DOI: 10.1016/j.ifacol.2018.09.049

Immigration and regional competitiveness - Relevant theories in the migration research and in the regional science

Tünde Patay

Publication Name: Deturope

Publication Date: 2018-01-01

Volume: 10

Issue: 1

Page Range: 71-81

Description:

International and interregional migrations, the geographic form of human mobility have a number of social, economic and political effects. These impacts can vary depending on the reference period, region or sector as well as on the goals and aspects of our interpretation. Another important question in connection with regional competitiveness is how decision makers act and react after perceiving migratory movements. Analysing the interference between immigration and regional development, we can rely on the well-known migration theories, however, a comparison of further models and concepts relating development and regional issues can be more useful for researchers. These questions are relevant, since the issues of the regional science, such as regional competitiveness and regional policy, have in the background strong associations with migratory phenomena. The aim of this study is to introduce the theoretical background, summarizing the mainstream solutions and the controversies as well. Thus the first part presents the role of the migration theories and these of the regional science in connection with the linkages between immigration and regional competitiveness. Besides it points out the importance of immigrants' inclusion. The next section focuses, complemented with the outcomes of a multivariate statistical analysis, on the theories on determinants and causalities of migration, exploring the connecting points with the issues of the regional policy.

Open Access: Yes

DOI: 10.32725/det.2018.004

Averaged vibration levels during courier parcel delivery service in small truck in Hungary

Péter Böröcz

Publication Name: Fme Transactions

Publication Date: 2018-01-01

Volume: 46

Issue: 2

Page Range: 211-217

Description:

In recent years there continues to be an increase in courier parcel delivery services due to the growing global online economy and express parcel shipments. It is therefore important to measure and quantify the levels of vibration that occur inside the vehicle during transport, as it can be one of the primary sources of damages. The purpose of this study was to measure the averaged vibration levels in vertical, lateral and longitudinal directions that occur in courier delivery shipments from pickup to delivery involving small trucks over ground road transportation in Hungary. The recorded acceleration data were analyzed in terms of power spectral densities (PSD) and presented with overall Grms. The results of the separated afnd averaged vibration levels provide physical circumstances for various road and load conditions showing those frequency bands that have significant intensities.

Open Access: Yes

DOI: 10.5937/fmet1802211B

On possibilistic dependencies: A short survey of recent developments

István Harmati Robert Fuller

Publication Name: Studies in Fuzziness and Soft Computing

Publication Date: 2018-01-01

Volume: 360

Issue: Unknown

Page Range: 261-273

Description:

Carlsson and Fullér introduced the notions of possibilistic mean value and variance of fuzzy numbers. Fullér and Majlender introduced a measure of possibilistic covariance between marginal distributions of a joint possibility distribution as the average value of the interactivity relation between the level sets of its marginal distributions. Fullér et al. introduced the possibilistic correlation ratio, the possibilistic correlation coefficient and the possibilistic informational coefficient of correlation. In this paper we give a short survey of some later works which extend and develop these notions.

Open Access: Yes

DOI: 10.1007/978-3-319-64286-4_16