Web-splines for electromagnetic theory
European Safety and Reliability Conference (ESREL 09)
September 2009, Prag, Tschechien
R. Mock, E. Kollmann, C. Ballhaus, H. Straumann
On the strength of experience with risk analysis methodology in IT-operating enterprises, an approach has to be able to deal with limited resources. This prompts an analyst to perform a heuristic and biased approach, which is typically a questionnaire structured by a IT security standard. The difficulty is to draw up a limited set of concise IT security related questions, which result in meaningful outcomes for IT risk analysis purposes. In the proposed approach, the Code of Practice ISO/IEC 27002 is used to structure the analysis and to restrict the number of questions. The Code's recommendations are rephrased and a Guttman scale is introduced for an IT security FMEA-like risk analysis approach. For frequency assessments it is assumed that an implemented high-level security measurement results in low frequencies of undesired events. The paper pictures the adapted IT-FMEA approach and presents the results of a feasibility study at Switzerland's leading telecom provider.
European Safety and Reliability Conference (ESREL 08)
September 2008, Valencia, Spanien
R. Mock, E. Kollmann, & E.Bünzli
Many industry sectors look back on a downright success story in development and implementing risk and reliability analysis methods. However the application of these methods seems to be questionable to enterprises in the area of information and communication technology (ICT) even though risk and reliability assessments are prominent on company and superordinate level. Major causes of reluctance are addressed in the paper:sophisticated analyses are not in line with the allocated resources. The acceptance of risk analysis methods in ICT strictly requires the inclusion of IT security issues and associated standards. The full performance of risk analysis to support the ranking of hazards or threats and prioritisation of measurements is often unknown to IT practitioners.The paper presents three projects accomplished at ICT operating enterprises in Switzerland in order to encircle the actual application of risk and reliability analyses in practice. Furthermore, it is outlined that national institutions as MELANI (Swiss Federal "Reporting and Analysis Centre for Information Assurance") support the risk analyses in enterprises. In order to communicate the full performance of risk and reliability methodology to IT practitioners, an extended educational concept is briefly presented.(ESREL 08; Vol 4). Valencia: Taylor & Francis; p. 2641-1421
IEEE European Electromagnetics (EUROEM'08)
July 2008, Lausanne, Switzerland
G. Apaydin, N. Ari
The analyses presented in this study show the
suitability of the proposed method to complex electromagnetic (EM) problems.
The finite element method (FEM) which uses weighted extended basis-splines
(web-splines) is applied to waveguides of arbitrary domain. The eigenvalue
analysis is used to compare the proposed method with the standard FEM. Firstly;
homogeneous essential boundary conditions can be modeled via weight function,
which is zero on the boundary and positive in the domain. Secondly, a well
conditioned basis can be obtained by extended b-splines. Combining these two
ideas gives the definition of web-splines.
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Web-splines for electromagnetic theory
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307 KB |
IEEE Mathematical Methods in Electromagnetic Theory (MMET'08)
June 2008, Odessa, Ukraine
G. Apaydin, N. Ari
This paper illustrates the weighted extended b-splines as basis functions
of finite element method of
arbitrary domain for waveguides. This method does not need mesh generation for
applications. The results are compared with the finite element method with
triangulation method using Lagrange basis functions. This method can be used in
more electromagnetic applications for future studies.
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Use of Web-splines of arbitrary domain for waveguides
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405 KB |
Applied Computational Electromagnetics Society Journal, vol 23, no. 2
June 2008 (SCI)
S. Seker, G. Apaydin
In this paper, a newly developed discrete
multilayer propagation model using scattering theory is studied using
rectangular lossy multilayer dielectric plates which model the walls, the
streets, and avenues in urban areas. The model is presented to study radio wave
propagation in street environments and to compare it with previous theoretical
and experimental studies. Good agreements are found. Using the developed model,
it is possible to calculate the contributions of direct and scattered wave
separately. The simulations reveal that the developed model can be applicable
for a broad band of frequencies. This model can be used effectively for
prediction of loss characteristics in a situation when two antennas are located
below the rooftops in conditions of direct visibility.
Discrete model,
path loss, urban areas, scattering, multilayer propagation model
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New physical discrete UHF multilayer propagation model for urban areas
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268 KB |
Int. Journal of electronics and Communicatins, vol. 62, no. 3, pp. 163-173,
Mar. 2008 (SCI)
G. Apaydin, S. Seker, N. Ari
The finite element method, which uses weighted
extended basis splines (web-splines) for solving two-dimensional
electromagnetic wave equations, has been studied. The web-spline method, which
does not need any mesh generation, is implemented easily. The web-spline method
is more accurate numerical technique than the standard finite-element method.
This new approach is applied to two-dimensional wave equations. The
approximated solutions are compared with the literature. Using web-splines,
more accurate results are obtained with fewer nodes.
Electromagnetics; Finite element method; Wave equation; Waveguides; Web-splines
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Application of web-spline method in electromagnetics
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636 KB |
Asia pacific Microwave Conference (APMC'07), December 2007, Bangkok, Tailand
S. Seker, G. Apaydin,
Electromagnetic (EM) scattering from curved surface and cylinder is important in the area of propagation and remote sensing in order to determine EM properties of scatterers. The radar cross sections (RCS) of a dielectric thin curved surface and cylinder are obtained by employing a quasi-static approximation. The results are complemented by numerical calculations and their validity is presented by comparison with available exact results in literature. Excellent agreement is found for horizontal and vertical polarization.
dielectric surface; radar cross section;
scattering
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Electromagnetic scattering properties of thin curved dielectric surface and cylinder |
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3.51 MB |
4th International on Electronics and Computer, October 2007, Bishkek, Kyrgyzstan
P. Schmid G. Apaydin
Nothing is carved in stone, especially not
the timetables at universities. But the students and the lecturers have to be
informed about the daily changes. Computers are at reasonable prices and
excellent free software is available. Why not build an electronic information
system from scratch using these components?
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Electronic information system for educational institutions
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423 KB |
Applied Mathematics and Computation, vol. 190, no. 2, pp. 1125-1135,
July 2007 (SCI)
G. Apaydin, S. Seker, N. Ari
This paper considers the weighted extended b-splines as basis function for finite element method in electromagnetics and compares with the standard finite element method applied to the two-point boundary value problems with different boundary conditions. This new approach, which provides more accurate results than standard finite element method, is presented to compare other numerical techniques and applied to one-dimensional electromagnetic problems. Computed results are compared with other numerical results in literature.
b-Splines; Electromagnetics; Finite element method; Web-splines
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Weighted extended b-splines for one-dimensional
electromagnetic problems |
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461 KB |
International Review of Progress in Applied Computional Electromagnetics (ACES'07)
March 2007, Verona, Italy
G. Apaydin, S. Seker, N. Ari
This paper illustrates the weighted extended b-splines as basis functions for finite element method in electromagnetics. This method does not need mesh generation, and is applied to coaxial waveguide applications. The results are compared with the exact solutions in literature. The maximum relative error is used for comparison. This method can be used in more electromagnetic applications for future studies.
Finite Element Method,
Waveguides, Web-splines
| Application of web-spline for coaxial waveguides |
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511 KB |
Proceedings of the European Safety and Reliability Conference 2006 (ESREL 2006)
September 2006, Estoril, Portugal
M. Kaegi, R. Mock, R. Ziegler & R. Nibali
Today society highly relies on complex information and communication
technology (ICT). However, this technology is difficult to handle for established risk and reliability analysis modelling techniques (e.g.Markov chains) in practice. In this regard analysis techniques need sophisticated capabilities to represent complex systems as well as applicability in a business framework. High-level Petri nets and agent-based modelling (ABM) overcome a few methodological constraints in risk analysis. However, the former looks laborious in practice when trying to extract risk and reliability figures. Changing the view from ICT to conceptual information
systems simplifies their representation and opens managerial knowledge sources. In this paper, an ABM technique is used. The associated metamodel consists of business processes, modelled by event-driven process chains and simulated by the means of a discrete event ABM (including human interactions, hardware failures, etc.). The case study "Ticket Reseller" shows and discusses its feasibility.
London: Taylor & Francis; p. 2277– 2284
3rd International Conference on Electronics and Computer, April 2006, Bishkek Kyrgystzan
G. Apaydin, N. Ari
This study illustrates b-splines as basis function for FEM in electromagnetics. The wave equation for one dimension has been compared with the exact results. Accurate and fast results are obtained while increasing order. This method can be used in electromagnetic applications in order to get better approximation in higher dimensions.
| Java-applet for wire interconnects as radiators |
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177 KB |
Int. Journal of Critical Infrastructures (Vol. 1, Nos. 2/3)
R. Mock, M. Corvo
Information and Communication Technology (ICT) has an important impact on critical infrastructure operation. However, the current use of risk analysis techniques has reached its limits when analysing these systems at least in practical terms. The application of extended event process chains (EPC) bypasses some of the difficulties, as they model business processes within an information system instead of much more complex hardware architectures and software interactions. The methodology
described in this paper integrates ARIS (Architecture Integrated Information Systems) and FMEA (Failure Mode and Effects Analysis), i.e., a business modelling method based on EPCs and a risk assessment technique which are well established in their areas of application and branches of competence. A novel risk representation is discussed. The practicability of the methodology is demonstrated by a feasibility study. Geneva: Inderscience Enterprises, 2005; p. 247 – 257
International Conference on Electronics and Computer
6. Mai 2005 Bishkek, Kyrgyzstan
Niyazi Ari, Jusupov Usonbek, Taalaibek Ashirov Bostonbekovic
This paper deals with Maple as a symbolic computation techniques. After introduction some capabilities of Maple, somme examples have been discussed to illustrate the Maple. A teaching model at a University is given within the conclusions.
symbolic computation techniques, Maple
| Symbolic Computation Techniques Using Maple |
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92 KB |
International Conference on Electronics and Computer
6. Mai 2005 Bishkek, Kyrgyzstan
Prof. Georg Brügger, Taalaibek Ashirov Bostobekovic
Understanding the fundamental structure of the universal Digital Signal Processor [DSP] Technology like as the mathematical and the different special commands written by the designated Assembler or High Level Language must be the first step in working with DSP. Learning the power of the different parallel mechanism given for the most DSP is one possibility to starting up with this powerful universal tool.
Digital Signal Processor [DSP], Microcontroller
| DSP and microicrocontroller functions on one board using FPGA |
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66 KB |
International Conference on Electronics and Computer
6. Mai 2005 Bishkek, Kyrgyzstan
Prof. Dr. sc. techn. ETH Niyazi Ari, Baha Kanberoglu, Usonbek Jusupov
The industry needs good EMC Engineers, not only for efficient solving the problems, but and for organising EMC management and EMC related products (and systems) development.
For the education of engineers in the EMC domain, we present the following possibilities: University activities, in-house courses for industry and co-ordination between University and Industry. This paper illustrates an education programm for engineers.
Main programm of the EMC-Education must include: Theory and numerical experiments; Experiments in EMC Labs and case studies.
EMC
| EMC-Education |
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414 KB |
LAPC/IEEE, April 2005, Loughborough, UK
S. Seker, G.Apaydin, R. Lang
In this paper we have introduced new RCS
model for the curved arbitrary dielectric surfaces, which can be thought as
consisting of N rectangular lossy dielectric plates. Our simulations revealed
that the developed model is applicable for a broad band of frequencies. This
model can be used effectively for prediction of RCS in situation when
dielectric surfaces are arbitrary and/or irregular shapes. If the shape of the
object is entered to simulation program in great detail, the output can be very
close to results, which are obtained by measurements.
RCS, Modeling,
Scattering, Curved Arbitrary Dielectric Surfaces
| RCS modelling and Simulation of curved arbitrary dielectric surfaces |
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123 KB |
Proceedings of PSAM7/ESREL 2004, Juni 2004, Berlin
R. Mock, R. Scherrer
The paper outlines the implementation of HRA in the framework of the IT-department of a major Swiss bank. The applicability of HRA techniques is shown by the case studies "Patch Management" and "Hardware Monitoring" which also include error probability assessments. Finally, a compilation of six case studies applying eight selected HRA techniques judges their practicability and usability. It is concluded that THERP and ASEP are the most appropriate techniques for analysing tasks in
system monitoring, testing, and operation.HRA techniques based upon PSF
are of limited practicability. Berlin, London, etc: Springer-Verlag,. 2004; p.650-655
IEEE Melecon 2004, May 2004, Dubrovnik, Croatia
S. Seker, C. Sezer, G.Apaydin
The
need for wireless communication data has increased considerably in past
decades. In this paper we have introduced new propagation model for the streets
and avenues in urban areas that can be thought as a wave-guide for EM-waves.
Using our developed model it is possible to calculate the contributions of each
direct and scattered wave separately. We don’t assume the sidewalls as perfect
conducting materials in our developed model unlike the previous studies. Our
simulations revealed that developed model is applicable for broadband of
frequencies. If the shape of the wave-guide is entered to simulation program in
great detail, the output can be very close to results that are obtained by
measurements. Even the shape is not entered very accurately; an approximate
result can be obtained if the fast result is needed.
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Discrete propagation model for mobile communications in urban environment |
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309 KB |
International Conference on Mathematical Methods in Electromagnetic Theory
April 2004, Bishkek, Kyrgyzstan
S. Seker, G.Apaydin
It is important to be able to quantify
both the absorption of electromagnetic (EM) energy in the human body and on
electronic devices and the resulting effects. In this study, the
electromagnetic radiation from electronic devices on the human and electronic
devices was investigated. The human head model was simulated. The results were
compared with the results of the studies in the literature, a good agreement
was obtained.
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Effects of electromagnetic fields on human beings and electronic devices |
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202 KB |
International Conference on Mathematical Methods in Electromagnetic Theory
01.04.2004 – 03.04.2004, Bishkek, Kyrgyzstan
(C-2004-2)
Prof. Dr. sc. techn. ETH Niyazi Ari, Taalaibek Ashirov Bostonbekovic, Usonbek Jusupov
Mesh free Method , Electromagnetics, PDE, FEM, mesh free method (MFM)
| Mesh Free Methods for Electromagnetics |
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8 KB |
International Conference on Computional Electromagnetic and Applications ICCEA 2004
Beijing, China
1. November 2004 - 4. November 2004
(C-2004-4)
Prof. Dr. sc. techn. ETH Niyazi Ari, Taalaibek Ashirov Bostonbekovic, Usonbek Jusupov
This paper illustrates the mesh free methods (MFM). Outgoing from introductory ideas for MFM, the basics of “Fast Multipole Method” FMM Tool explained. Some applications for the electromagnetnetic fields using different boundary conditions have been computed and discussed. As examples, a periodic structure has been studied under different boundary conditions and the solutions are given as contour plots.
Mesh free Methods, Periodic Structurs, Fast Multipole Method
| Mesh Free Methods for Periodic Structurs |
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120KB |
| Location and tracking techniques of GSM phones and applications | G. Apaydin, S. Seker, E. Aydemir | Advanced Engineering Design 2003 (3rd international conference in Prague) June 2003 |
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Electric Field Measurements of Different Mobile Headset in Near Zone |
S. Seker, G. Apaydin, C. Celik |
EMC'2003 IEEE, May 2003 |
| Simulating and Modeling Electromagnetic Fields using Symbolic Computations | G. Onbilgin, N. Ari, O. Okan | The 2003 IEE International Symposium on EMC Istanbul, Turkey, May 11-16 2003 |
| EMC Education at Sakarya University | A. Tesneli, Z. Demir, N. Ari, O. Okan | The 2003 IEE International Symposium on EMC Istanbul, Turkey, May 11-16 2003 |
| Microprocessor Controller Broad Band Balun System Design | M. Kahriman, N. Ari, O. Cerezcu, A. Teseli, S. Ozen | The 2003 IEE International Symposium on EMC Istanbul, Turkey, May 11-16 2003 |
| Theoretical and Experimental Investigation of Box-To-Box Antenna Coupled EMI Noise on an Helicopter under the Influence of Rotors | F. Ustuner, O. Cerezci, N. Ari, S. Seker, Z. Demir, B. Kilic | The 2003 IEE International Symposium on EMC Istanbul, Turkey, May 11-16 2003 |
| EMC Education | N. Ari | The 2003 IEE International Symposium on EMC Istanbul, Turkey, May 11-16 2003 |
| Transfer Impedance of Contacting Double Braided Coaxial Screens | B. Colak, O. Cerezci, N. Ari | The 2003 IEE International Symposium on EMC Istanbul, Turkey, May 11-16 2003 |
| Modelling of electrically contacting double braid coaxial cable shielding as triaxial cable shields | B. Colak, O. Cerezci, N. Ari | EMC 15th International Zurich Symposium on EMC (accepted in 2002) Paper R7 |
| Symbolic Computation Techniques for Aperture Antennas | N. Ari, A.Tesneli S. Seker, O. Cerezci, pp. 466-468 | Mathematical Methods in Electromagnetic Theory, Sep 10-13 2002 Kiev-Ukraine |
| A Study for the fast solution of electromagnetic scattering problems : A wavelet based approach | M. Bahattin Kurt, Niyazi Ari, Osman Cerezci pp. 463-465 | Mathematical Methods in Electromagnetic Theory, Sep 10-13 2002 Kiev-Ukraine |
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Risk Analysis Related Issues of IT-Systems: Case Studies in Review |
R. Mock,F. Möhle, & A. Fischer Amsterdam, etc.: Elsevier Science Ltd., 2002; p. 1885 – 1890 |
Proceedings of PSAM6 June 2002, San Juan, Puerto Rico |
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Theoretical and Experimental Study of Electromagnetic Fields arround High Power Transformers |
G. Apaydin, S.Seker |
ELECO'2001 IEEE, Nov. 2001 |
| Mühendislik Problemerinin cözümünde Sembolik hesap yöntemlerini kullanilmasi ( Application of Symbolic Computation Techniques to Engineering Problems) | N. Ari, A.Y. Tesneli pp. 91-92 | XIV Ulusal Mathematik Symposium 19-21 Sept. 2001 Eskisehir Türkei |
| Symbolic Computation Techniques for Electromagnetics | N. Ari, B. Türetken | Proceedings of the second International Symposium on Mathematical & Computational Applications, Sept. 1-3, 1999 Baku, Azerbeijan |
| Theoretical and Experimental Shielding Study of Offices | P. Karacagil, S.S. Seker, F. Üstüner, N. Ari,pp. 423-427 | EMC-Symposium, Poland, 1998, June 23-25 |
©
2010
HSZ-T
|
N.Ari
| Letzte Änderung:
24.09.2009
http://www.hsz-t.ch/publikationen/fachartikel