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Found 5164 publications

Modeling and simulation for the energy storage by ultracapacitor in urban rail car

Istvan Szenasy

Publication Name: 3rd International Conference on Electrical and Control Technologies ECT 2008

Publication Date: 2008-01-01

Volume: Unknown

Issue: Unknown

Page Range: 239-242

Description:

This paper focuses on the use of modeling and simulation for the renewable energy. An energy storage system for improving performance of electric vehicles is presented. The supercapacitor contributes to the rapid energy recovery associated with regenerative braking in electric vehicles. This power system allows the acceleration and deceleration of the vehicle with minimal loss of energy. Short-distance passenger traffic on electrified lines is a domain where brake energy recuperation might reduce the total energy consumption significantly. In this paper the results of a simulation model by Matlab for an urban-metro railcar is presented.

Open Access: Yes

DOI: DOI not available

Measuring and control the hysteresis loop by using analog and digital integrators

Miklós Kuczmann Zoltán Pólik

Publication Name: Journal of Optoelectronics and Advanced Materials

Publication Date: 2008-01-01

Volume: 10

Issue: 7

Page Range: 1861-1865

Description:

We have managed to build up a computer controlled measurement system applying National Instruments Data Acquisiton card and National lnsturments LabVIEW software package. First, in a previous study, the specimen under test has been simulated by the Jiles-Atherton model of hysteresis, but simulated measurements have been performed using LabVIEW functions. Our main goal now is to control the magnetic flux density measured by using a toroidal shape core with a feedback controller. In this paper, we show the developed procedure which is able to measure the hysteresis characteristics applying analog and digital integrators, and to control the waveform of magnetic flux density determined from the induced voltage of the secondary coil wound on the toroidal shape core. Our experience is that the developed controller is robust. This work is an initial step of the vector hysteresis measurement system.

Open Access: Yes

DOI: DOI not available

Reversible DC-to-DC converter for a dual voltage automotive system using zero voltage switching technique

Dan V. Nicolae Petre Scortaru Zoltán Puklus Mihai Cernat

Publication Name: 11th International Conference on Optimization of Electrical and Electronic Equipment Optim 2008

Publication Date: 2008-01-01

Volume: Unknown

Issue: Unknown

Page Range: 251-258

Description:

A novel hysteretic controller for a bi-directional dc-dc converter with ZVS and interleaving for dual voltage systems in automobiles is presented. A variable frequency extended band hysteretic current control method is proposed. In comparison with classical fixed frequency current control PWM, the reverse polarity peak current needed for ZVS operation is kept constant Inductor current ripple decreases with load reduction. Automatic changes in operation between buck and boost modes are accomplished without transient currents. Converter simulations are carried out using Matlab/Simulink platform.

Open Access: Yes

DOI: 10.1109/OPTIM.2008.4602417

Selection of tool materials for cold forming operations using a computerized decision support system

J. Gram I. Czinege I. Felde T. Reti D. Y. Ju

Publication Name: Proceedings of the 17th Ifhtse Congress

Publication Date: 2008-01-01

Volume: 2

Issue: Unknown

Page Range: 773-775

Description:

A computerized decision support system (DSS) is outlined which is designated primarily to selcct the proper tool steel grades for various cold forming operations. This computerized system contains four data base: data base of cold forming operations and tools, of work materials, of cold forming tool materials and of wear resistant PVD coatings. The decision strategy makes it possible to select appropriate tool materials taking into consideration their most important material properties (wear resistance, toughness, compressive yield strength, tempering resistance, dimensional stability, machinability, and material price). The practical advantages of the developed decision support system are demonstrated on example.

Open Access: Yes

DOI: DOI not available

Preliminary data of life and health insurance in the Roman Law (the collegium funeraticium and the collegium tenuiorum)

Ágnes Váradi

Publication Name: Orvosi Hetilap

Publication Date: 2007-12-30

Volume: 148

Issue: 52

Page Range: 2477-2481

Description:

With the explosion of insurance contracts in the last two hundred years both in Europe and around the rest of the world, there is a temptation to think that the financing and insuring on projects on limited or non-recourse terms is a relatively novel concept. This is, however, far from being true. Indeed, there is an early evidence of project financing techniques and insurance contracts being actively used during the ancient times. The first examples come from the Roman law but there are similar legal institutions even in the ancient Greek legal system. - The essay analyses the legal history of assurances on lives and health in the Roman law, especially the question of the collegium tenuiorum and the collegium funeraticium. In the centre of the studies are the analyses of their legal personality, the changes in the regulation concerning their foundation, the purpose and the internal organisation. The treatment of the main topics begins with fragments from the material of the Corpus Iuris Civilis by Justinian. After that the views of the most important authors and the contemporary investigations in the Roman law found the statements of the paper. - As a result of these analyses we can see the process of development in the ancient legal systems, especially in the Roman law. And although these results have no immediate influence on the present legal regulation, it can demonstrate original tendencies in the field of insurances. This way we can prove that the Roman law is a still existing basis for the development in contractual law.

Open Access: Yes

DOI: 10.1556/OH.2007.28274

What drives small retailers to adopt an integrated marketing communications approach?

Hongyan Yu Bill Merrilees Laszlo Jozsa Kim Shyan Fam

Publication Name: Proceedings Icsssm 07 2007 International Conference on Service Systems and Service Management

Publication Date: 2007-12-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

This study has sought to explain the determinants of what leads certain retailers and not others to adopt an integrated marketing communications (IMC) approach. A sample of 512 retailers in Australian capital cities were used to explore this question. Logit regression analysis has been used to identify the key determinants. The conclusion is that the size of the retail promotion budget and whether or not the retailer is part of a chain organisation are the two critical factors in explaining the adoption of an IMC approach. Both of these factors were positive and highly significant. Other factors had a very minor role to play in explaining the adoption of IMC. The paper concludes by suggesting two key managerial implications for both the large and small retailers in relation to optimising their promotion budget. © 2007 IEEE.

Open Access: Yes

DOI: 10.1109/ICSSSM.2007.4280211

Near Field Communication technology: Contactless applications in mobile environment

Balázs Benyó

Publication Name: 8th International Symposium of Hungarian Researchers on Computational Intelligence and Informatics Cinti 2007

Publication Date: 2007-12-01

Volume: Unknown

Issue: Unknown

Page Range: 175-188

Description:

StoLPaN, a pan-European consortium of companies, universities and user groups co-funded by the European Commission (EU), Information Society Technologies (IST) Programme aims to define open commercial and technical frameworks for the remote management of NFC-enabled (NFC: Near Field Communication) services on mobile devices. These frameworks will facilitate the deployment of NFC-enabled mobile applications across a wide range of vertical markets, regardless of the phone type and the nature of the services required. This paper introduces the application opportunities of the NFC technology, the business aspects of the NFC based service development and the technical infrastructure implementing the core of the NFC-enabled services.

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

Determination of DC micro-motor characteristics by electrical measurements

A. Nagy P. Horváth

Publication Name: Recent Advances in Mechatronics

Publication Date: 2007-12-01

Volume: Unknown

Issue: Unknown

Page Range: 278-282

Description:

It is generally difficult to carry out and measure breaking moments precisely in the mNm range. Instead of traditional methods using brake and additional mechanical elements to determine torque vs. angular velocity characteristics of micro-motors this paper suggest a new procedure based on purely electrical measurements. Theoretical background of the measuring procedure is discussed detailed. The suggested method is shown in the case of a RF300E DC micro-motor. © 2007 Springer-Verlag Berlin Heidelberg.

Open Access: Yes

DOI: 10.1007/978-3-540-73956-2_55