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Found 6289 publications

Learning the optimal parameter of the Hamacher t-norm applied for fuzzy-rule-based model extraction

László Gál Rita Lovassy L. T. Kóczy Imre J. Rudas

Publication Name: Neural Computing and Applications

Publication Date: 2014-01-01

Volume: 24

Issue: 1

Page Range: 133-142

Description:

Mamdani-type inference systems with trapezoidal-shaped fuzzy membership functions play a crucial role in a wide variety of engineering systems, including real-time control, transportation and logistics, network management, etc. The automatic identification or construction of such fuzzy systems input output data is one of the key problems in modeling. In the past years, the authors have investigated several different fuzzy t-norms, among others, algebraic and trigonometric ones, and the Hamacher product by substituting the standard "min" t-norm operation, in order to achieve better model fitting. In the present paper, the focus is on examining the general parametric Hamacher t-norm, where the free parameter quite essentially influences the quality of modeling and the learning capability of the model identification system. Based on a wide scope of simulation experiments, a quasi-optimal interval for the value of the Hamacher operator is proposed. © 2013 Springer-Verlag London.

Open Access: Yes

DOI: 10.1007/s00521-013-1499-3

Beer game - Demonstration and performance evaluation of supply chains

No authors available

Publication Name: Proceedings of the European Conference on Games-based Learning

Publication Date: 2014-01-01

Volume: 2

Issue:

Page Range: 732-741

Description:

Professionals need special skills in supply chain management to perform all the required tasks - organising material and information flow, product development, forecasting, customer services and relations, warehousing, decision making and performance measurement. The scientific literature and empirical studies show consistently that in addition to this complex frame of operations the bullwhip effect is presence in every case. This expensive phenomena is hard to detect and measure, and able to cause serious problems in the chains. We consider the game based learning is an effective way to gain experiences rather than acquire only the theoretical background. The beer game as supply chain simulation is widely accepted in the demonstration of system dynamics and investigations of bullwhip effect. Considering the advantages and drawbacks of the numerous versions of the game we created android software for the trainings. The paper based training is hard to follow, in the boardgame the participants can't satisfy the basic rule of not sharing any information and the online version won't make the common/group learning possible. Our training use the beer game simulation connected with the Balanced Scorecard measurement system helps the participants to develop skills in recognition of the bullwhip effect, being familiar with the triggers and impacts, have tools for mitigation and the skill of choosing or designing solutions in the specific cases. The participants can study the theories, evaluate several inventory and order strategies and they also get instant feedback on the impact of their decisions.

Open Access: No

DOI: DOI not available

Assessment of particle confinement within a mechanically stabilised layer

No authors available

Publication Name: 10th International Conference on Geosynthetics, ICG 2014

Publication Date: 2014-01-01

Volume:

Issue:

Page Range: Unknown

Description:

The effect of geogrids on unbound granular fill by the mechanism of mechanical interlock has been established with particle confinement identified as being an important component influencing the performance of the resulting mechanically stabilised layer. Evaluation of the influence of geogrids on particles through the thickness of the mechanically stabilised layer has been carried out using a large multi-level shear box. The results obtained from the programme of testing carried out at the University of Gyor will be discussed by reviewing measured shear resistance at several levels in the granular fill to characterise the influence of the geogrid on particle confinement through the granular layer thickness.

Open Access: No

DOI: DOI not available

Frequencies and resonances around L4 in the elliptic restricted three-body problem

Renáta Rajnai B. Érdi I. Nagy

Publication Name: Monthly Notices of the Royal Astronomical Society

Publication Date: 2014-01-01

Volume: 443

Issue: 3

Page Range: 1988-1998

Description:

More and more Trojan asteroids are discovered in our Solar system, suggesting that they are probably a common spinoff of planet formation and evolution. Till date we know thousands of Trojan followers of Jupiter, and Trojan asteroids and moons of other major planets have also been discovered. The large number of such celestial bodies can mean that Trojan companions to extrasolar planets may also be common. Trojan celestial bodies are examples for the Lagrangian triangular solutions of the three-body problem. In this paper, the stability of the Lagrangian point L4 is investigated in the elliptic restricted three-body problem by using Floquet's theory. Stable and unstable domains are determined in the parameter plane of the mass parameter and the eccentricity by computing the characteristic exponents. Frequencies of motion around L4 have been determined both in the stable and unstable domains, and fitting functions for the frequencies are derived depending on the mass parameter and the eccentricity. Resonances between the frequencies are studied in the whole parameter plane. It is shown that the 1:1 resonances are not restricted only to single curves but extend to the whole unstable domain. In the unstable domains, longer escape times of the test particle from the neighbourhood of L4 are related to certain resonances, but changing the parameters the same resonances may lead to faster escape.© 2014 The Authors.Published by Oxford University Press on behalf of the Royal Astronomical Society.

Open Access: Yes

DOI: 10.1093/mnras/stu1212

Robust reconfigurable control for in-wheel motor vehicles

Timea Fülep Péter Gáspár Andras Mihaly Zoltán Szabó Ferenc Szauter József Bokor

Publication Name: 2014 IEEE International Electric Vehicle Conference Ievc 2014

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The paper deals with reconfigurable control of in-wheel electric vehicles. Basically the vehicle is controlled alone by the four electric engines mounted in the wheels of the vehicle. The goal is to design a control system with velocity and trajectory tracking ability realized by separate torque generation of the in-wheel motors. In critical driving situations when the yaw moment cannot be established with the four in-wheel engine alone, the high-level controller reconfigures the actuator inputs, thus steering intervention helps to stabilize the vehicle. Moreover, a multi-layer supervisory architecture for integrated control systems is also proposed. The operation of the vehicle is illustrated through a CarSim simulation example.

Open Access: Yes

DOI: 10.1109/IEVC.2014.7056232

A virtual audio environment for testing dummy-head HRTFs modeling real life situations

József Répás György Wersényi

Publication Name: Proceedings of Forum Acusticum

Publication Date: 2014-01-01

Volume: 2014-January

Issue: Unknown

Page Range: Unknown

Description:

Virtual audio simulators usually incorporate HRTF filtering and headphone playback. The most important parameters for simulation include accuracy and spatial resolution of the applied HRTFs, setting the individual parameters (customization) and further signals processing algorithms in order to equalize the headphone or tracking head movements. This paper presents a custom built MATLAB-based virtual audio environment for listening tests using various dummy-head HRTFs, ITD setting methods, headphone equalization etc. Furthermore, first results from a listening test for comparison of HRTFs recorded with a manikin wearing hair or glasses are also presented.

Open Access: Yes

DOI: DOI not available

A dynamic programming approach for 4D flight route optimization

Gabor Takacs Christian Kiss-Toth

Publication Name: Proceedings 2014 IEEE International Conference on Big Data IEEE Big Data 2014

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: 24-28

Description:

This paper describes our solution for the GE Flight Quest 2 (FQ2) challenge, organized by Kaggle. FQ2 aimed at optimizing flight routes so that the overall cost depending on fuel consumption and delay is as low as possible. The contestants could use several data tables as inputs, including aircraft positions and destinations, weather information and other aviation related data. Their task was to produce a flight plan for each flight, given as a list of (latitude, longitude, altitude, airspeed) quadruplets. The cost of the flight plans was evaluated with an open source simulator. Our proposed method produces an initial solution with the Dijkstra's algorithm to avoid restricted zones, and then refines it using dynamic programming and local search techniques. We can extensively utilize wind forecasts and significantly divert the planes from the the great circle route if necessary. Moreover, our method tries to set the ascending and descending profiles of the flights to further decrease the cost. Our algorithm achieved second place on the public, and fifth place on the private leaderboard of the contest.

Open Access: Yes

DOI: 10.1109/BigData.2014.7004427

Method for determining direction, velocity and position of a flying ball

A. Nagy

Publication Name: Mechatronics 2013 Recent Technological and Scientific Advances

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: 401-408

Description:

This paper proposes an algorithm for an optical measuring system, which is capable of calculating the velocity and position components, the radius and the trajectory of a flying sphere-shape ball. The infrared light-emitting diodes and the IR sensors of the system are arranged in a single plane and create a lattice of infrared light beams. The FPGA based hardware of the system measures the points in time when the light beams are interrupted by the ball. The proposed algorithm uses the measured time-data with the associated positions of the interrupted light beams as input. The practical application such a systems can be measuring ball's velocity in several sports and games. © Springer International Publishing Switzerland 2014.

Open Access: Yes

DOI: 10.1007/978-3-319-02294-9_51

Improving the accuracy of a fuzzy-based single-stroke character recognizer by antecedent weighting

A. Tormási L. T. Kóczy

Publication Name: Studies in Fuzziness and Soft Computing

Publication Date: 2014-01-01

Volume: 317

Issue: Unknown

Page Range: 165-179

Description:

In this chapter we present an improved version of the fuzzy based single-stroke character recognizer introduced in previous works. The modified recognition method is able to reach higher accuracy in the character recognition without any significant effect on the computational complexity of the algorithm. Different fuzzy rule and antecedent weighting techniques were successfully used to improve the efficiency of fuzzy systems especially in classification problems. The altered recognizer reached 99.49 % average recognition rate with 26 different single-stroke symbols (based on Palm’s Graffiti alphabet) without learning userspecific parameters or modifying the rule-base. The new algorithm has the same computational complexity as the original system does.

Open Access: Yes

DOI: 10.1007/978-3-319-06323-2_11