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Found 6289 publications

Adapted queueing algorithms for process chains

Peter Foldesi András Rövid Ágnes Bogárdi-Mészöly

Publication Name: Smart Innovation Systems and Technologies

Publication Date: 2011-12-01

Volume: 10 SIST

Issue: Unknown

Page Range: 65-73

Description:

Process chains are a common modeling paradigm for analysis and optimization of logistic processes, and are intensively used in many practical applications. The ProC/B toolset is a collection of software tools for modeling, analysis, validation and optimization of process chains. The ProC/B models can be translated into queueing networks or Petri nets, which can be solved by effective techniques and algorithms to evaluate performance metrics. The base queueing model with Mean-Value Analysis evaluation algorithm, and their adaptations for modeling thread pool and queue limit have been verified and validated for multi-tier software systems. The goal of our work is to adapt these models and algorithms for process chains to model parallel processes and queue limit. © 2011 Springer-Verlag Berlin Heidelberg.

Open Access: Yes

DOI: 10.1007/978-3-642-22194-1_7

Representation of loss aversion and impatience concerning time utility in supply chains

János Botzheim Peter Foldesi Edit Süle

Publication Name: Smart Innovation Systems and Technologies

Publication Date: 2011-12-01

Volume: 10 SIST

Issue: Unknown

Page Range: 273-282

Description:

The paper deals with the investigation of the critical time factor of supply chain. The literature review gives a background to understand and handle the reasons and consequences of the growing importance of time, and the phenomenon of time inconsistency. By using utility functions to represent the value of various delivery-times for the different participants in the supply chain, including the final customers, it is shown that the behaviour and willingness of payment of time-sensitive and non time-sensitive consumers are different for varying lead times. Longer lead times not only generate less utility but impatience influences the decision makers, that is the time elasticity is not constant but it is function of time. For optimization soft computing techniques (particle swarm optimization in this paper) can be efficiently applied. © 2011 Springer-Verlag Berlin Heidelberg.

Open Access: Yes

DOI: 10.1007/978-3-642-22194-1_28

Interpretation of loss aversion in Kano's quality model

János Botzheim Peter Foldesi

Publication Name: Smart Innovation Systems and Technologies

Publication Date: 2011-12-01

Volume: 10 SIST

Issue: Unknown

Page Range: 165-174

Description:

For designing and developing products/services it is vital to know the relevancy of the performance generated by each technical attribute and how they can increase customer satisfaction. Improving the parameters of technical attributes requires financial resources, and the budgets are generally limited. Thus the optimum target can be the achievement of the minimum overall cost for a given satisfaction level. Kano's quality model classifies the relationships between customer satisfaction and attribute-level performance and indicates that some of the attributes have a non-linear relationship to satisfaction, rather power-function should be used. For the customers' subjective evaluation these relationships are not deterministic and are uncertain. Also the cost function are uncertain, where the loss aversion of decision makers should be considered as well. This paper proposes a method for fuzzy extension of Kano's model and presents numerical examples. © 2011 Springer-Verlag Berlin Heidelberg.

Open Access: Yes

DOI: 10.1007/978-3-642-22194-1_17

Controlled bidirectional energy transfer by ultracapacitors in electric drive

Z. Puklus András Fehér

Publication Name: 12th IEEE International Symposium on Computational Intelligence and Informatics Cinti 2011 Proceedings

Publication Date: 2011-12-01

Volume: Unknown

Issue: Unknown

Page Range: 31-34

Description:

This paper shows the possibility of the two-directional energy transfer between energy sources using the example of ultracapacitors. The showed method allows bidirectional energy transfer between power systems which use different voltage levels. We used PSIM program to simulate the bidirectional energy transfer and study the operation of the applied model. © 2011 IEEE.

Open Access: Yes

DOI: 10.1109/CINTI.2011.6108526

Compression ignition linear engine design variable effects

Cs Tóth-Nagy Parviz Farmouri Nigel N. Clark

Publication Name: American Society of Mechanical Engineers Internal Combustion Engine Division Publication ICE

Publication Date: 2011-12-01

Volume: Unknown

Issue: Unknown

Page Range: 1029-1036

Description:

A linear engine/alternator was simulated and designed, and a prototype was built at West Virginia University. This paper describes the engine and presents original operational data. The linear engine was a two-cylinder, two-stroke, common rail direct injection, compression ignition engine. The engine was built using off the shelf components to reduce cost where it was possible. Engine control, injection duration and timing, were achieved using a microcontroller with piston position as a control input. Experiments on the engine were performed to study its behavior. The studied variables included mass of the translator, amount of fuel injected, injection timing, load, and stroke with operating frequency and mechanical efficiency as the basis of comparison. At this point of development, the engine was far from optimized; however, the trends in engine behavior were clear. Increasing the translator mass resulted in decreased operating frequency. Increasing the stroke length also resulted in decreased operating frequency. Overcharging and increased fueling rate, both, resulted in increased power output, efficiency, and operating frequency. Advancing injection timing resulted in increased frequency, efficiency and power output, and decreased stalling frequency. This suggests that the engine operated in an HCCI-like fashion. © 2011 by ASME.

Open Access: Yes

DOI: 10.1115/ICEF2011-60157

Displacement measurement by digital holographic interferometry

Lotfi Abdelhakim

Publication Name: Proceedings of the 13th International Conference on Civil Structural and Environmental Engineering Computing

Publication Date: 2011-12-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Digital holographic interferometry is a useful technique for measuring the deformation or displacement of the surface of an object by recording at least two speckle patterns, one before and one after the object is deformed. Holographic interferometry utilizes interference between the speckled image of an object illuminated by a laser and a reference beam derived from the same laser. Any change in the shape of the object results in local changes in the intensity distribution in the holographic fringe pattern. The holograms are generated directly on a charge coupled device (CCD) target and stored electronically. The speckle patterns can be taken quickly and analyzed using holographic interferometry and the Fourier transform method. © Civil-Comp Press, 2011.

Open Access: Yes

DOI: DOI not available

Test generation and computational complexity

Jozsef Sziray

Publication Name: Proceedings of IEEE Pacific Rim International Symposium on Dependable Computing Prdc

Publication Date: 2011-12-01

Volume: Unknown

Issue: Unknown

Page Range: 286-287

Description:

The paper is concerned with analyzing and comparing two exact algorithms from the viewpoint of computational complexity. They are: composite justification and the D-algorithm. Both serve for calculating fault-detection tests of digital circuits. As a result, it is pointed out that the composite justification requires significantly less computational step than the D-algorithm. From this fact it has been conjectured that possibly no other algorithm is available in this field with fewer computational steps. If the claim holds, then it follows directly that the test-generation problem is of exponential time, and so are all the other NP-complete problems in the field of computation theory. © 2011 IEEE.

Open Access: Yes

DOI: 10.1109/PRDC.2011.40

Spectral properties of fullerene graphs

Tomislav Došlić Tamás Réti

Publication Name: Match

Publication Date: 2011-12-01

Volume: 66

Issue: 3

Page Range: 733-742

Description:

We use a result from the theory of geometric representation of graphs to show that the separator of a fullerene graph on n vertices cannot exceed 24/n, thus improving the best currently known upper bound of 1-3/n. The result is then combined with a recently established upper bound on the smallest eigenvalue of fullerene graphs to show that there are only finitely many Ramanujan fullerenes. That settles down a conjecture on fullerenes made by the Graffiti software.

Open Access: Yes

DOI: DOI not available

Neural-network based modelling approach for loading systems

Gabriella Orbán Tibor Vadvári András Rövid Peter Varlaki

Publication Name: International Conference on Emerging Trends in Engineering and Technology Icetet

Publication Date: 2011-12-01

Volume: Unknown

Issue: Unknown

Page Range: 72-76

Description:

As in many fields in modern logistics the system modelling and identification play an important role. By the modelling of complex non-linear systems different model approximation approaches are utilized. The approximation methods of mathematics are widely used in theory and practice for several problems. In the framework of the paper a higher order singular value decomposition (HOSVD) based approximation approach for neural network (NN) model approximation is introduced. The approach will be detailed from the point of view of logistic systems but it may be applicable for other fields, as well. The NNs in this case stand for local models based on which a more complex parameter varying model can numerically be reconstructed and reduced using the HOSVD. © 2011 IEEE.

Open Access: Yes

DOI: 10.1109/ICETET.2011.69