242 research outputs found
A review of discrete solutions of poisson, laplace, and wave equations
No full textSevgi, Levent (Dogus Author)One- and two-dimensional discrete solutions of Poisson, Laplace, and wave equations are given in this tutorial. The terms wave propagation and numerical propagation are discussed. Simple MATLAB scripts are also supplied.IEEE Antennas and Propagation Societ
Modeling and simulation strategies in wireless propagation and coverage planning
No full textUluışık, Çağatay (Dogus Author) -- Sevgi, Levent (Dogus Author)This paper presents two-dimensional (2D) user-friendly, tailored with attractive and useful graphical user interfaces (GUI), Matlab propagation packages based on the classical knife-edge model and the parabolic equation method that can handle realistic propagation scenarios with non-flat, arbitrarily-designed and user-selected terrain profiles. Any 2D propagation scenario may be built by the user, and field vs. range and/or height profiles can be simulated
Correction to: Bearing fault detection in adjustable speed drives via self-organized operational neural networks (Electrical Engineering, (2024), 10.1007/s00202-024-02764-3)
No full textIn the original publication, the affiliation of first author has been wrongly tagged to second author of the paper. The authors and affiliations should have appeared as follows: Sertac Kilickaya1, Levent Eren21Faculty of Information Technology and Communication Sciences, Tampere University, Korkeakoulunkatu 7, 33720, Tampere, Finland 2Department of Electrical and Electronics Engineering, Izmir University of Economics, Izmir, Turkey The original article has been corrected.Non peer reviewe
Design of a novel microstrip electromagnetic bandgap (EBG) structure
No full textSevgi, Levent (Dogus Author)This paper presents the design, simulation, and experimentation of a novel low-cost small-size high-performance microstrip (MS) electromagnetic bandgap (EBG) structure for MIMIC applications. The simulations and measurements confirm that the stopband characteristics can be easily controlled by changing the stub lengths and the interstub gap
Identity, interests and political culture in Turkey's accession negotiations
No full textKırval, Levent (Dogus Author)This chapter analyses the potential impact of the political culture differences between Turkey and the EU on the ongoing accession negotiations. It also analyses the ways to include the Turkish model successfully within the embryonic post-national formulation emerging in Europe. To this end, as well as the necessary transformations Turkey has to go through, the steps for a further deepening of European integration, which will also allow the coexistence of different political cultures, is analysed in a comparative perspective
Novel digital broadcast / communication systems and groundwave propagation prediction requirements
No full textSevgi, Levent (Dogus Author) -- Conference full title: European Conference on Antennas and Propagation: EuCAP 2006; Nice; France; 6 November 2006 through 10 November 2006The use of novel broadcast and communication systems require reviewing and revisiting investigations of propagation characteristics over the Earth's surface along realistic propagation paths through inhomogeneous atmosphere in connection to the international standards like ITU, IEC and ETSI. The aim is to review early analytical studies as well as novel time and frequency domain powerful numerical techniques, and to discuss newly-introduced Matlab-based virtual propagation prediction tools that can be used for educational and research purposes
Validation, verification and calibration in numerical electromagnetics : Canonical tests and comparisons
No full textSevgi, Levent (Dogus Author)Modeling and numerical simulation in electromagnetics is discussed in this paper with emphasize placed on validation, verification and calibration. Canonical examples from antennas, propagation to microstrip circuits are presented. Tests against measurements, when available, are also presented.IEEE,IEEE Electromagnetic Compatibility Society,International Union of Radio Science, URSI,Research-and-production Enterprise "Proryv
Electromagnetic modeling and simulation
No full textElectromagnetic modeling is essential to the design and modeling of antenna, radar, satellite, medical imaging, and other applications. In Electromagnetic Modeling and Simulation, author Levent Sevgi explains techniques for solving real-time complex physical problems using MATLAB-based short scripts and comprehensive virtual tools. The book thoroughly covers the physics, mathematical background, analytical solutions, and code development of electromagnetic modeling. Access to online MATLAB scripts and coding tools render this book an ideal resource for electrical engineers and researchers
Essays in mechanism design:
No full textThis dissertation consists of three essays in the theory of mechanism design under incomplete information. In the first essay, we analyze an implementation problem in which monetary transfers are feasible, valuations are interdependent and the set of available choices lies in a product space of lattices. This framework is general enough to subsume many interesting examples, including allocation problems with multiple objects. We identify a class of social choice rules which can be implemented in ex post equilibrium. We identify conditions under which ex post efficient social choice rules are implementable using monotone selection theory. The key conditions are extensions of the single crossing property and supermodularity. These conditions can be replaced with more tractable conditions in multiobject allocation problems with either two objects or two agents. I also show that the payments which implement monotone social decision rules coincide with the payments of (1) the classical Vickrey-Clarke-Groves mechanism with private values, and (2) the generalized Vickrey auction introduced by Ausubel [1999] in multiunit allocation problems.
The second essay generalizes the analysis of optimal (revenue maximizing) mechanism design for the seller of a single object introduced by Myerson [1981]. We consider a problem in which the seller has several heterogeneous objects and buyers' valuations depend on each other's private information. We analyze two nonnested environments in which incentive constraints can be replaced with more tractable monotonicity conditions. We establish conditions under which these monotonicity conditions can be ignored, and show that several earlier analyses of the optimal mechanism design problem can be unified and generalized. In particular, problems with two complementary goods in Levin [1997] and multiunit auction problems in Maskin and Riley [1989] and Branco [1996] are special cases.
The third essay considers the problem of selling internet advertising slots to advertisers. Under suitable conditions, we solve for the payments imposed by an optimal mechanism and show that it can be decentralized via prices using a linear assignment approach. At every configuration of private information, optimal mechanism can be interpreted as a menu consisting of a price for every slot.Ph. D.Includes bibliographical references (p. 69-70)by Levent Ulk
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