Cilt 4, Sayı 4, Aralık 2006
Permanent URI for this collectionhttps://hdl.handle.net/11413/327
Browse
Browsing Cilt 4, Sayı 4, Aralık 2006 by Language "en_US"
Now showing 1 - 13 of 13
- Results Per Page
- Sort Options
Publication Open Access A Study On Spectral And Statistical Analysis Of Noisy Signals For Physical Processes(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Kaynaş, Tayfun; Şeker, SerhatIn this study, it is considered a sinusoidal signal with is third harmonic as well as the fundamental frequency adding the noise term, which is produced using a Gaussian random number generator. Hence spectral and statistical properties of this signal are examined and Signal-to-Noise Ratio (SNR) is computed comparing with the probability function of the noisy signal.Publication Open Access Coexisting Attractors In A Autonomous 4ᵗʰ Order, Non Linear, Electric Circuit(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Stouboulos, Ioannis N.In this paper we have studied the dynamic behavior of a non driven electric circuit of 4th order with two active elements, one linear negative conductance & one non linear resistür ofN-type exhibiting a symmetrical piecewise linear v-i characteristic. The resistor Ri serves as the control parameter of the system. We have observed formation of "bubbles" for some initial conditions. In a narrow region of Ri values what has been observed is antimonotonicity in the bifurcation diagram, different routes to chaos via period doubling sequences and reverse period doubling and transition from periodic to quasi-periodic and finally to chaos. We have also studied the dependence of circuit behavior on the initial conditions.Publication Open Access Does A Chaotic System Dynamic Really Exist In Nature Or Is It A Misconception Dynamics?: A Hypothesis(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Demirer, R. Murat; Çağlar, Mert; Oya Demirer; POLATOĞLU, YAŞAR; TR108339; TR199370The theory of nonlinear dynamieal systems deals with deterministie systems that exhibit a eomplieated and random-Iooking behavioL Life seienees have been one of the most applieable areas for the ideas of ehaos beeause of the eomplexity of biologieal systems. it is widely appreeiated that ehaotie behavior dominates physiologieal systems. However, as an extension of this trend, a new hypothesis is proposed that the existenee of embedded nonlinear systems suggest a new rationale fundamentally whieh is different from the classic approaeh. A biologieal system can be eonsidered as a simple explanation of transitions breaking up generic orbits onto higher dimensions with eovering maps by preventing ehaos. We seek to diseuss and understand how a biologieal system can deerease its vulnerability to sensitivity at system transitions what we define those transitions as injeetive immersions of differentiable smooth manifolds with eaeh eorresponding to a transition to different state Iike synehronization, anti-synehronization and oseillator-death when network strueture varies abruptly and asynehronously. We can then eonsider a biologieal system if an existenee of such a unique immersed smooth submanifoJd into higher dimensional space can be shown that there is no ehaotie dynamies assoeiated with a map from one manifold to another one when the system is perturbed. We then will introduee an open problem whether Melnikov funetion is a eontinuously deereasing funetion for smail perturbations which this distanee funetion serves as a diseriminate funetion for implieations of the ehaos transitions.Publication Open Access Dynamics Of Two Coupled, Nonlinear, Autonomous 4ᵗʰ Order Circuits(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Papadopoulou, Maria S.; Kyprianidis, Ioannis M.; Stouboulos, Ioannis N.In this paper we have studied the case of chaotic synchronization of two identical, mutually coupled, non linear, 4th order autonomous electric circuits. Each circuit contains one linear negative conductance G and one non linear resistür RNwith a symmetrical piecewise-linear v-i characteristic. Using the capacitances Ci and Ci as the control parameters, we have observed the transition from periodic states to chaotic ones and vise versa, as well as crisis phenomena. We have established the mutual coupling via a variable resistür Rx.We have observed that synchronization is possible as the resistance of the coupling element is varied.Publication Embargo Dynamics On Relaxed Newton's Method Derivative(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Özer, Mehmet; Hacıbekiroglou, Gürsel; Valaristos, Antonios; Miliou, Amalia N.; Anagnostopoulos, Antonios N.; Cenys, Antanas; POLATOĞLU, YAŞAR; TR2509; TR199370In the present report the dynamic behaviour of the one dimensional family of maps f(x) = b(x + ar}' is examined, for representative values of the control parametres a, b and A.. These maps are of special interest, since theyare solutions of N;j = 2 , where N;j is the Relaxed Newton's method derivative. The maps f(x) are proved to be solutions of the non-linear df(x) fJ[.r/..I](1+A)/A fJ 1 b-1/A differential equation, dx - '. J \Xi , where = /l. •. The reccurent form of these maps, Xn = b(xn_i + arA, after excessive iterations, shows in a Xn vs. A. plot, an initial exponential decay followed by a bifurcation. The value ofA. at which this bifurcation takes place, depends on the values of the parameters a, b. This corresponds to a switch to an oscillatory behaviour with amplitudes of f (X) undergoing a period doubling. For values of a slightly higher than i and at higher A.'s areverse bifurcation occurs and a bleb is formed. This behaviour is confirrned by calculating the corresponding Lyapunov exponent.Publication Open Access Experimental Study Of A Nonlinear Circuit Described By Duffing's Equation(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Volos, Christos K.; Kyprianidis, Ioannis M.; Stouboulos, Ioannis N.We have studied experimentallyan electronic circuit that implements the Duffing equation. The circuit appears periodic and non-periodic (chaotic) dynamics behavior, as we vary the amplitude of the driving voltage signal Va. The expected operation of the circuit was confirmed, by comparing the experimental results with the results of the simulation. From the study of the circuit's behavior, very important phenomena conceming the Chaos theory were detected, such as the great sensitivity of the circuit to initial conditions, the route to chaos through the mechanism of period doubling and the phenomenon of crisis of chaotic attractors.Publication Open Access Investigation Of Effects Of Cross-Sections on The Ray-Effect Distortions(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Sağlam, S.In this study, a wellknown numerieal method has been used to solve neutron transport equation and the ray-effeet anomaly observed on the results of the method hase been introdueed. To examine the effeets of eross-seetions on the ray-effeet, two Benehmark problems have been ehosen as test problems. Then, two dimensional transport code, TWOTRAN-1I has been exeeuted for these problems for 84-816 approximations. Finally, by eomparing all the results with eaeh other, the effeets of eross-seetions have been examined in detail.Publication Embargo Modeling The Nonlinear Behaviour Of A Driven Varactor Resonator At Low Frequencies(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Kalomiros, John A.; Stavrinides, Stavros G.; Miliou, Amalia N.; Özer, Mehmet; Bulat, Taner; TR2509We monitor the theoretical response of an R-L-Varactor circuit by using Multisim 7.0, at a driving frequency f= 1MHz with high driving amphtudes. Atlow frequencies a bifurcation is observed, attributed to the large capacitance emerging from the carrier injection at reverse-bias breakdown. By inereasing driving amplitude we observe non-periodic trajectories with increasing chaotic content in a four dimensional state-space. At specific amplitudes we monitor two-dimensional tori where trajectories are periodic, like in a two-oscillatorssystem with commensurate frequencies. The scenario from quasi-periodocity to chaos is discussed by means of estabhshed tools, hke the circle map, Poincare cross sections, power and FFT spectra, correlation dimension and Kolmogorov entropy. Peak amphtudes of the monitored waveforms are shown to form an interesting pattem of well defined groups, within the resolution ofthe numerical solutions produced by the simulation.Publication Open Access Reverse Period Doublings In A 3ᴿᴰ Order Nonlinear And Autonomous Electric Circuit(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Kyprianidis, Ioannis M.; Fotiadou, Maria E.We have studied the dynamics of Chua's canonical circuit, when the v-i characteristic of the nonlinear resistor of the circuit is a smooth cubic function. Unlike the monotone bifurcation behavior of the members of Chua' s circuit family with a piecewise linear resistor, reverse period doublings, as a parameter of the circuit is varied in a monotone way, have been observed in the circuit we have studied. Dynamics of the circuit is very sensitive to initia\ conditions, as chaotic attractors coexist with period-l limit cycles.Publication Embargo Schwarzian Derivative Revisited(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Çağlar, Mert; Demirer, R. Murat; POLATOĞLU, YAŞAR; TR199370The Boolean-algebraic structure of the so-called Schwarzian derivative is investigated. A sufficient condition for a function of several variables to behave chaotically, which concerns its associated Schwarzian derivative, is also given.Publication Open Access The Application Of The Modified From Of Bath's Law To The North Anatolian Fault Zone (NAFZ), Aegean Graben System And Cyprus Arc Zone(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Yalçın, Sibel Ebru; Kurnaz, LeventEarthquakes and aftershock sequences follow several empirical scaling laws: (1) Gutenberg-Richter frequency-magnitude scaling, (2) Bi'ith's law for the magnitude of the largest aftershock, (3) The modified Omori's law for the temporal decay of aftershocks. In this paper, "The Modified Form of Bi'ith's Law" and its application to our KOERI data have been studied. Bi'ith's law states that the differences in magnitudes between mainshocks and their largest aftershocks are approximately constant, independent of the magnitudes of mainshocks. In the modified form of Bi'ith's law for a given mainshock we get the inferred "largest" aftershock of this mainshock by using an extrapolation of the Gutenberg-Richter frequency-magnitude statistics of the aftershock sequence. To test the applicability of the modified form of Bi'ith's Law we consider i4 large earthquakes that occurred in and near boundary neighbors of Turkey between i900 and 2004 with magnitudes equal to or greater than ffims ~ 6.1. Because Turkey has different fault zones that have different properties, a classification was needed for these earthquakes. Additional\y, in this study the partitioning of energy during a mainshock-aftershock sequence was also calculated in two different ways. it is shown that most of the energy is released in the mainshock. The constancy of the differences in magnitudes between mainshocks and their largest aftershocks is an indication of scale-invariant behavior of aftershock sequences.Publication Open Access The Effect Of Noise And Parameter Mismatch On The Synchronization Of The Drive-Response Chaotic System(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Antoniades, Ioannis P.; Miliou, Amalia N.; Stavrinides, Stavros G.; Anagnostopoulos, Antonios N.We present a thorough investigation of the effect ofnoise (internal or extemal) on the synchronization of a drive-response configuration system (unidirectional coupling between two identIcal systems). Moreover, since in every practical implementation of a communication system, the transmitter and receiver circuits (although identical) operate under slightly different conditions it is essential to consider the case of the mismatch between the parameters of the transmitter and the receiver. In OUT work we consider the non-autonomous 2nd order non-linear oscillator system presented by G. Mycolaitis, et aZ in Pmc. onth Int. Workshop on Non-linear Dynamics ofElectronic Systems, which is particularly suitable for digital communications.Publication Open Access Yarının Organizasyonları İçin Bugünden İpuçları(İstanbul Kültür Üniversitesi Yayınları, 2006-12) Taşcı, Deniz; Koç, UmutFord ve Taylor bundan yaklasik yüz yil önce bilimsel bilgiyi üretim organizasyonlarinda uygulamislardir. 20. Yüzyilin sonlarinda çesitli ortamlarda yapilan degerlendirmelerde, her ikisi de 20. Yüzyili en derinden etkileyen insanlarin arasinda yer almislardir. Onlara ilham veren iklim, 20. Yüzyilin son çeyreginden itibaren yogunlasarak degismistir. Yerini bambaska bir iklime birakmistir. Yeni iklim is organizasyonlarinin karsilastiklari sorunlarin dogasini köklü biçimde dönüstürmüstür. Özellikle 1990']arin baslarindan itibaren dünyaya bakisimizin köklü bir biçimde degismeye basladigi, ilgilendigimiz sistemlerin hemen hepsinin daha önce çok da önemsemedigimiz bir dizi niteligini giderek daha iyi tanimaya basladiginnz söylenebilir. Bu baglamda, giderek daha iyi kavramaya basladiginnz niteliklerin hepsini kompleksiik basligi altinda toplamak da mümkün görünmektedir.