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Found 6289 publications

Computational simulation of mesopic vision based on camera recordings

Gábor Dömötör András Horváth

Publication Name: Light and Engineering

Publication Date: 2014-01-01

Volume: 22

Issue: 1

Page Range: 61-67

Description:

Understanding mesopic vision is one of the hottest topics in lighting engineering [1]. The high importance of the field comes from the wide variety of the applications such as driving and other outdoor activities are performed in mesopic conditions at night. Therefore, it is extremely important to calculate the visibility of different objects in such conditions. In this paper, we present the algorithm and the first results of software, which is able to simulate the behaviour of human retina in scotopic, mesopic and photopic ranges, calculates the direction-dependent acuity. Our aim was to produce a practical tool to examine real-time situations. Therefore, classical camera recordings are used as input, which limits the accuracy but extends the range of applications.

Open Access: Yes

DOI: DOI not available

Fuzzy State Machine-Based Refurbishment Protocol for Urban Residential Buildings

Gergely Molnarka L. T. Kóczy

Publication Name: Communications in Computer and Information Science

Publication Date: 2014-01-01

Volume: 443 CCIS

Issue: PART 2

Page Range: 375-384

Description:

The urban-type residential houses built before World War Two represent a large part of the built environment in Hungary. Due to their physical condition and low energy-efficiency the retrofit of these buildings is very much advisable nowadays. In this paper we propose an approach based on fuzzy signatures and state machines, that helps decision support for determining the renovation scenario concerning necessity, cost efficiency and quality. Using the knowledge obtained from diagnostic surveys done during the previous decades by architect experts, and technical guides and the available database of contractors billing, a protocol for the preparation for optimized refurbishment is proposed, based on the concept of an extended fuzzy state machine model. In this combined model the theoretical concepts of finite-state machine and fuzzy state machine, and also the principles of fuzzy signatures are applied. © Springer International Publishing Switzerland 2014.

Open Access: Yes

DOI: 10.1007/978-3-319-08855-6_38

Fuzzy based hierarchical performance evaluation in telecommunications access networks

Ferenc Lilik L. T. Kóczy

Publication Name: 2014 International Conference on Humanoid Nanotechnology Information Technology Communication and Control Environment and Management Hnicem 2014 7th Hnicem 2014 Joint with 6th International Symposium on Computational Intelligence and Intelligent Informatics Co Located with 10th Erdt Conference

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Performance evaluation of wire pairs of telecommunications access networks is a great challenge for telecommunications service providers. Although there are existing methods and systems for it, these are expensive or unpunctual. This paper presents a novel, hierarchical fuzzy inference based performance evaluation method for wire pairs of access networks, which is based on measurements of the pairs. The set of antecedent (input) parameters and their role in the evaluation, the consequent (output) states and the type of the used fuzzy rule bases are presented. In addition, the behavior and the role of the noise that can be measured in the wire pairs are detailed.

Open Access: Yes

DOI: 10.1109/HNICEM.2014.7016242

Hierarchical robust control for in-wheel motor vehicles

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

Publication Name: Proceedings of the Mini Conference on Vehicle System Dynamics Identification and Anomalies

Publication Date: 2014-01-01

Volume: 2014-January

Issue: Unknown

Page Range: 71-81

Description:

The paper proposes the design of an integrated vehicle control system for in-wheel electric vehicle, which is able to track road geometry with a predefined reference velocity. In the design the lateral and longitudinal dynamics are combined using the in-wheel motors and the steering system. The design methodology of the hierarchical control is proposed. The required control signals are calculated by applying high-level controllers, which are designed using a robust control method. For the control design the model is augmented with weighting functions specified by the performance demands. The actuators generating the necessary control signals in order to achieve the requirements for which low-level tracking controllers are designed.

Open Access: Yes

DOI: DOI not available

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

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

Definition and examination of waterway capacity

Gábor Horváth

Publication Name: International Conference on Industrial Logistics Icil 2014 Conference Proceedings

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: 143-149

Description:

Hungary - situating in the centre of the continent - is one of the most loaded transit country in Europe. There are many TEN-T corridors crossing the country. The external cost coming from the heavy road transport is very high. On the other hand there are other eco-friendly transport modes available like railway or inland navigation. In the general approach navigation is an untrustworthy technology and has uncertain capacity. The present study tries to change this opinion bringing new turn of mind. There are more way to define the waterway capacity. Because of the dynamic hydrological changes the cross-section has no stability, like road or railway cross-section. The paper shows these differences and deals with ,theoretical and planned capacity ,capacity factors ,flexibility analysis ,question of measure units ,time factor. Copyright © FSB, Zagreb, Croatia, 2014.

Open Access: Yes

DOI: DOI not available

Towards to haptic keyboard: Modeling the piano action

P. Horváth

Publication Name: Mechatronics 2013 Recent Technological and Scientific Advances

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: 49-55

Description:

Keyboards of digital pianos have moderate dynamic performance compared to that of grand pianos. Real needs emerged to emulate haptic features of a piano action by a simple device. This paper deals with analytical and experimental investigation of check and repetition phase of touch. Finding out the relationship among initial velocity of hammer, duration and magnitude of impact impulse, key position, fly of time gives sound foundation for development of a haptic keyboard that offers the same sensation for pianist as the acoustic one. Parameters of governing expressions were determined by measurements. © Springer International Publishing Switzerland 2014.

Open Access: Yes

DOI: 10.1007/978-3-319-02294-9_7

On the asymptotic behavior of spatially implicit models of competition of two species with overcolonization

Éva V.P. Rácz Irma Szimjanovszki János Karsai

Publication Name: Dynamic Systems and Applications

Publication Date: 2014-01-01

Volume: 23

Issue: 4

Page Range: 677-690

Description:

We consider patch-based population dynamics, called metapopulations, and investigate the spread of two species and their competition for habitat areas. Let 0 ≤ p1,p2 denote the proportion (density) of the areas occupied by the species 1 and 2, respectively. Obviously, 0 ≤ p1 + p2 ≤ 1. Both species can locally extinct and colonize empty patches or patches occupied by the other with different rates. Hence the model is P1′ = κ1P1 (1 - P1 - P2) - e1p1p2-C1P1P2 - C2P1P2 P2′ = κ1P1 (1 - P1 - P2) - e1p1p2-C1P1P2 - C2P1P2 where ej are the extinction rates, κ1 are the rates of colonization of empty patches, and species "i" overcolonize "j" with the rate c1(i,j=1,2; i≠j) We investigate the asymptotic stability properties of the equilibria of such systems and we give a complete characterization of the parameter space. We prove that there can appear a globally asymptotically stable coexisting equilibrium. On the other hand, this equilibrium can become unstable and then the exclusive equilibria are only locally asymptotically stable. We have also developed dynamic applications in Wolfram Mathematica to illustrate our results.

Open Access: Yes

DOI: DOI not available