Gábor Rózsa

24491300900

Publications - 5

Fuzzy signature based description of complex overtaking and engagement conflicts in railway traffic control

Gábor Rózsa Á Ballagi L. T. Koczy

Publication Name: IEEE AFRICON Conference

Publication Date: 2015-11-18

Volume: 2015-November

Issue: Unknown

Page Range: Unknown

Description:

The railway traffic system and its respective subsystems, especially station and timetable management are extremely large and complex systems comprising a multitude of complex structured data. The theoretical and pre-planned traffic control is calculating with idealized traffic situations, but the real life scenes often suffer from conflicts and deviations. The complex traffic conflict states include uncertain conditions and vagueness of information. Classical methods cannot work properly under these uncertain conditions. In this paper we propose a new approach to describe these complex conflict situations using fuzzy signatures for recognizing and describing traffic conflicts in a hierarchically structured manner.

Open Access: Yes

DOI: 10.1109/AFRCON.2015.7331929

Training electrical engineers on asynchronous logic circuits based on constant weight codes

Gábor Rózsa A. Nagy P. Keresztes L. T. Koczy

Publication Name: IEEE AFRICON Conference

Publication Date: 2011-12-12

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The paper introduces a new way for teaching of delay insensitive asynchronous logic circuits. The studies start on high level models, which are VHDL implementations of Dennis-type static dataflow systems. Investigating the operation of the concurrent processes of these models, the main elements of the delay insensitive systems can be derived. Introducing constant weight 'm-of-n' codes immediately at the beginning of the course leads to a proper generalization. So the well known dual-rail code circuits can be considered as special cases of the constant weight code delay insensitive circuits. The paper presents briefly the design practice sessions for students. © 2011 IEEE.

Open Access: Yes

DOI: 10.1109/AFRCON.2011.6072041

The application of fuzzy logic for the solving of conflicts in the dispositional tasks of a railway traffic control center

Tibor Héray Gábor Rózsa István Tömpe L. T. Koczy

Publication Name: IEEE AFRICON Conference

Publication Date: 2009-12-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The paper considers a railway timetable related problem in a simplified form, generated by the delay of one or several incoming trains at a given station. Usually there are connecting trains in the timetable, especially in up to date periodic timetables and thus incoming delays might indicate the necessity of introducing a delay with connecting outgoing trains. A hierarchical fuzzy rule base is applied in order to determine the optimal outgoing delay, taking also usual restrictions into consideration. Three examples are shown. © 2009 IEEE.

Open Access: Yes

DOI: 10.1109/AFRCON.2009.5308167

Delay propagation in a real life railway network controlled by a fuzzy logic rule base

Tibor Héray Gábor Rózsa Mark Farkas L. T. Koczy

Publication Name: 10th International Symposium of Hungarian Researchers on Computational Intelligence and Informatics Cinti 2009

Publication Date: 2009-12-01

Volume: Unknown

Issue: Unknown

Page Range: 423-433

Description:

This paper considers a real-life railway timetable related problem, where a set of interconnected railway junction points form a railway network, which is essentially a directed graph with corresponding vertex and edge capacities representing railway tracks and railway platforms.The dynamic behavior of this model is driven by a timetable. Unforeseen weather and other external effects may contribute to delays in the timetable, which alters the behavior of the whole system. In this scenario a hierarchical fuzzy system is proposed that can suggest a possible outgoing delay for each train by evaluating a set of fuzzy rule bases using two input data. The first proposal does not take into account the possible propagation of delay in the whole railway network. In this article a negative feedback is applied on the hierarchical fuzzy system.The fuzzy sets are optimized by an evolution based global search metaheuristics.

Open Access: Yes

DOI: DOI not available

The possible applications of Fuzzy logic for the treatment of conflicts in the dispositional tasks of railway traffic control centers

Tibor Héray Gábor Rózsa L. T. Koczy

Publication Name: IEEE AFRICON Conference

Publication Date: 2007-12-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

the handling of traffic conflicts of trains is rather complicated if full dynamic models are used. Often it is senseless to take into consideration all details of the motion equations and environmental parameters especially as the main parameters, like maximum speed of the trains involved are not exactly known. Also, a large number of noise type variables are always available. The paper proposes the use of the Mamdani type fuzzy rule based reasoning algorithm for handling railway traffic conflicts. The essential point is the granulation of all important parameters into a relatively small number of categories labeled by terms such as small, large, etc. This way the possible decisions for a concrete traffic conflict situation get various fuzzy weights after accumulation of all the fired rules. The final (non-fuzzy) decision is taken by choosing the option with the largest weight. A simplified example is presented for a delay and overtaking type conflict. ©2007 IEEE.

Open Access: Yes

DOI: 10.1109/AFRCON.2007.4401624