arif nacaroglu - Academia.edu (original) (raw)
Papers by arif nacaroglu
Signal Processing, 2014
We study l p ð0 o p o 1) minimization under both additive and multiplicative noise. Theorems are ... more We study l p ð0 o p o 1) minimization under both additive and multiplicative noise. Theorems are presented for completely perturbed l p ð0 o p o 1) minimization. Theorems reveal that under suitable conditions the stability of l p minimization with certain values of 0 o p o 1 is limited by the noise level in the observation. The restricted isometry property condition and the worst case reconstruction error bound are given in terms of restricted isometry constant and relative perturbations. Simulation results are presented and compared to state-of-the-art methods.
In this study two algorithms are compared in order to reconstruct a block sparse signal from spar... more In this study two algorithms are compared in order to reconstruct a block sparse signal from sparsely corrupted measurements using Compressive Sampling / Compressed Sensing (CS). Compressive sampling / Compressed sensing (CS) is a new area of signal processing and attracts too much attention in recent years. Compressive sampling states that if a signal having length N has a sparse representation on an orthonormal basis, then it is possible to recover this signal exactly from M≪N measurements. Two algorithms are studied to reconstruct the original signal one is based on optimization and the other is based on greedy algorithms.
In this paper, nonrecursive digital filter design u sing the exponential window is investigated [... more In this paper, nonrecursive digital filter design u sing the exponential window is investigated [1,2]. The exponential window proposed by the author [3] has computational cost advantage compared to the well-known Kaiser w indow due to having no power series expansion in its time domain repres entation. First, the filter design equations for th e exponential window to meet the given low pass filter specification are establi shed. And then, the comparison with the other 2-par ameter windows, namely Cosh and Kaiser, is discussed. The simulation resul ts show that the filters designed by the exponentia l w ndow provide significantly better far end stopband attenuation, which is important for some applications, than the filt rs designed by the Cosh and Kaiser windows, while performing worse stopband ttenuations near the stopband frequency.
On the base of signal flow graphs, a general method is described for the design of switched-capac... more On the base of signal flow graphs, a general method is described for the design of switched-capacitor networks by using minimum number of switches and capacitors. The method involves the search of the best network among many possibilities for the realization of a given z-domain transfer function and it is easily implemented by digital computers
2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
Digital signal processing is widely used and important for digital filter design. In this paper, ... more Digital signal processing is widely used and important for digital filter design. In this paper, a new window function is presented. Window function is applied to the coefficients of the FIR Filters obtained by using Fourier Series. In literature, there have proposed some window functions until now, such as cosh window, Kaiser window, Exponential window and etc; a new and efficient wondow function is proposed with combination of Blackman Window and three adjustable parameter Cosh Window. Lots of mathematical models are applied using proposed window function. Especially, filter length and adjustable parameters of proposed window function are analyzed to find the best optimized values of them. These obtained data try to prove on known filter types, such as low pass filter, high pass filter and band pass filter. Proposed window function is succesfull for side lobe region and ripple ratio compared to other proposed window functions in literature.
2008 6th International Symposium on Communication Systems, Networks and Digital Signal Processing, 2008
In this paper, nonrecursive digital filters design using the modified Kaiser window is investigat... more In this paper, nonrecursive digital filters design using the modified Kaiser window is investigated. The well known 2-parameter Kaiser window is modified by introducing a new third parameter. Two examples are given to compare the performances of the filters designed by the modified Kaiser window and the well known adjustable windows in literature such as the ultraspherical, Saramald, Kaiser and
2008 3rd International Conference on Information and Communication Technologies: From Theory to Applications, 2008
In this paper a new class of adjustable window functions based on cosine hyperbolic function is p... more In this paper a new class of adjustable window functions based on cosine hyperbolic function is proposed. The proposed window, namely cosh window for short, has been derived in the same way of the derivation of Kaiser window but it has the advantage of having no power series expansion in its time domain function. The spectral characteristic of cosh window
2012 20th Signal Processing and Communications Applications Conference (SIU), 2012
Bu çalışmada kısmi destek kümesiönceden bilinen seyrek ve sıkıştırılabilir işaretlerin geri çatıl... more Bu çalışmada kısmi destek kümesiönceden bilinen seyrek ve sıkıştırılabilir işaretlerin geri çatılması için p < 1 degerli kısmi destek kümeli lp küçümseme ele alınmıştır. Seyrek işareti geri çatmak için kısmi destek kümesi bilinen lp küçümseme tabanlı yöntemönerilmiş ve geri çatmak için kısmi destek kümesi bilinen lp küçümseme metodunun gerekli şartları verilmiştir. Teorik sonuçlara göre kısmi destek kümesi bilinen lp küçümseme tabanlı metod kararlı ve dayanıklı bir yapı göstermiştir. Ayrıca numerik sonuçlara göre, lp küçümseme metodu klasik kısmi destek kümesi bilinen sıkıştırmalı algılamaya göre daha az sayıdä olçüm sayısına ihtiyaç duyarak işaretin geri çatılmasına olanak saglamıştır.
2011 IEEE 19th Signal Processing and Communications Applications Conference (SIU), 2011
Bu çalışmada seyrek bozulmuş ölçümlerden seyrek işareti geri kazanmak için alternatif bir yol ola... more Bu çalışmada seyrek bozulmuş ölçümlerden seyrek işareti geri kazanmak için alternatif bir yol olarak yinelemeli ağırlıklı en küçük kareler yöntemi (IRLS) çalışılmaktadır. Bilindiği üzere sıkıştırmalı algılama teorisi, dik bir dönüşümle seyrek olarak ifade edilebilen N boyutlu bir işaretin M<<N ölçüm kullanarak tekrar tam olarak geri kazanılabileceğini göstermiştir. l 1 minimizasyon yerine p<1 olmak kaydıyla l p minimizasyon kullanılması ölçüm sayısını daha da düşürebilir. Seyrek bozulmuş ölçümlerden işaretlerin geri kazanımı için farklı p değerleri kullanılan IRLS ve yinelemeli tekrar ağırlıklı l 1 minimizasyon simülasyon sonuçları verilmektedir. Simülasyonlardan elde edilen sonuçlara göre yinelemeli tekrar ağırlıklı l 1 minimizasyona göre daha az ölçüm sayısı tam olarak geri kazanım için yeterli gelmektedir.
2010 IEEE 18th Signal Processing and Communications Applications Conference, 2010
ABSTRACT
2008 3rd International Conference on Information and Communication Technologies: From Theory to Applications, 2008
In this study, 2-parameter cosh window is modified to improve its spectral characteristic in term... more In this study, 2-parameter cosh window is modified to improve its spectral characteristic in terms of the ripple ratio by proposing a new additional parameter. It is observed that an increase in the new parameter results in wider mainlobe width and smaller ripple ratio. By choosing the suitable combinations of the two adjustable parameters for the proposed modified window, the
2013 The International Conference on Technological Advances in Electrical, Electronics and Computer Engineering (TAEECE), 2013
In this study, a brief review of the memristor and its terminal equations are given. Biquadratic ... more In this study, a brief review of the memristor and its terminal equations are given. Biquadratic filter implementation with memristor is introduced. SPICE subcircuit model is presented to simulate the memristor. Gain and phase characteristics of the proposed biquadratic filter are obtained with SPICE circuit simulator. It is observed that filter parameter such as cut off frequencies, band width, quality factor are adjustable by memristor parameters and the power consumption of the biquadratic filter with memristor is low and has better efficiency.
Signal & Image Processing : An International Journal, 2013
In this paper we propose a new class of 2-parameter adjustable windows, namely Exponential window... more In this paper we propose a new class of 2-parameter adjustable windows, namely Exponential window, based on the exponential function [1,2]. The Exponential window is derived in the same way as Kaiser window was derived, but our proposed window is more computationally efficient because in its time domain function it has no power series expansion. First, the spectrum design equations for the Exponential window are established, and the spectral comparisons are performed with Cosh, Kaiser and ultraspherical windows. The proposed window is compared with Cosh and Kaiser windows, and the results show that for the same window length and mainlobe width the Exponential window provides better sidelobe roll-off ratio characteristic, which may be important for some applications, but worse ripple ratio. The second comparison is performed with ultraspherical window for the same window length, mainlobe width and sidelobe roll-off ratio and the results demonstrate that the Exponential window exhibits better ripple ratio for the narrower mainlobe width and larger sidelobe roll-off ratio, but worse ripple ratio for the wider mainlobe width and smaller sidelobe roll-off ratio.
2008 Ph.D. Research in Microelectronics and Electronics, 2008
In this paper a new class of adjustable windows based on the exponential function is proposed. Th... more In this paper a new class of adjustable windows based on the exponential function is proposed. The proposed window has been derived in the same way of the derivation of Kaiser window, but it has the advantage of having no power series expansion in its time domain function. The spectrum design equations for the proposed window are established, and the
Signal Processing, 2013
ABSTRACT We study recovering sparse and compressible signals using I-p minimization with p &l... more ABSTRACT We study recovering sparse and compressible signals using I-p minimization with p < 1 when some part of the support of the signal is known a priori. Sparse reconstruction method based on I-p minimization with partially known set is proposed and recovery conditions are given. Theoretical results show that I-p minimization with partially known support is stable and robust. Experimental results are presented to expose the modification of I-p minimization improves performance and need fewer samples to reconstruct the signal.
International Journal of Circuit Theory and Applications, 1993
On the basis of signal flow graphs a general method is described for the design of stray-insensit... more On the basis of signal flow graphs a general method is described for the design of stray-insensitive switched capacitor networks. To be able to choose the optimum one, the method involves the search of all possible topologies for the specially formed signal flow graph of the given z-domain transfer function and is easily implemented by digital computer. 2. FORMULATION Let the z-domain transfer function of the SC network to be designed be Consider the SFG shown in Figure I , which is a generalization of the graph given in Reference 3. Let the branches have transmittances in the forms Ki = ai + biz-', Gi = C; + diz-' where i = 1,2, ..., n; a;, b;, c; and d; are real numbers. The overall gain of this SFG can be calculated to be
Signal Processing, 2014
We study l p ð0 o p o 1) minimization under both additive and multiplicative noise. Theorems are ... more We study l p ð0 o p o 1) minimization under both additive and multiplicative noise. Theorems are presented for completely perturbed l p ð0 o p o 1) minimization. Theorems reveal that under suitable conditions the stability of l p minimization with certain values of 0 o p o 1 is limited by the noise level in the observation. The restricted isometry property condition and the worst case reconstruction error bound are given in terms of restricted isometry constant and relative perturbations. Simulation results are presented and compared to state-of-the-art methods.
In this study two algorithms are compared in order to reconstruct a block sparse signal from spar... more In this study two algorithms are compared in order to reconstruct a block sparse signal from sparsely corrupted measurements using Compressive Sampling / Compressed Sensing (CS). Compressive sampling / Compressed sensing (CS) is a new area of signal processing and attracts too much attention in recent years. Compressive sampling states that if a signal having length N has a sparse representation on an orthonormal basis, then it is possible to recover this signal exactly from M≪N measurements. Two algorithms are studied to reconstruct the original signal one is based on optimization and the other is based on greedy algorithms.
In this paper, nonrecursive digital filter design u sing the exponential window is investigated [... more In this paper, nonrecursive digital filter design u sing the exponential window is investigated [1,2]. The exponential window proposed by the author [3] has computational cost advantage compared to the well-known Kaiser w indow due to having no power series expansion in its time domain repres entation. First, the filter design equations for th e exponential window to meet the given low pass filter specification are establi shed. And then, the comparison with the other 2-par ameter windows, namely Cosh and Kaiser, is discussed. The simulation resul ts show that the filters designed by the exponentia l w ndow provide significantly better far end stopband attenuation, which is important for some applications, than the filt rs designed by the Cosh and Kaiser windows, while performing worse stopband ttenuations near the stopband frequency.
On the base of signal flow graphs, a general method is described for the design of switched-capac... more On the base of signal flow graphs, a general method is described for the design of switched-capacitor networks by using minimum number of switches and capacitors. The method involves the search of the best network among many possibilities for the realization of a given z-domain transfer function and it is easily implemented by digital computers
2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
Digital signal processing is widely used and important for digital filter design. In this paper, ... more Digital signal processing is widely used and important for digital filter design. In this paper, a new window function is presented. Window function is applied to the coefficients of the FIR Filters obtained by using Fourier Series. In literature, there have proposed some window functions until now, such as cosh window, Kaiser window, Exponential window and etc; a new and efficient wondow function is proposed with combination of Blackman Window and three adjustable parameter Cosh Window. Lots of mathematical models are applied using proposed window function. Especially, filter length and adjustable parameters of proposed window function are analyzed to find the best optimized values of them. These obtained data try to prove on known filter types, such as low pass filter, high pass filter and band pass filter. Proposed window function is succesfull for side lobe region and ripple ratio compared to other proposed window functions in literature.
2008 6th International Symposium on Communication Systems, Networks and Digital Signal Processing, 2008
In this paper, nonrecursive digital filters design using the modified Kaiser window is investigat... more In this paper, nonrecursive digital filters design using the modified Kaiser window is investigated. The well known 2-parameter Kaiser window is modified by introducing a new third parameter. Two examples are given to compare the performances of the filters designed by the modified Kaiser window and the well known adjustable windows in literature such as the ultraspherical, Saramald, Kaiser and
2008 3rd International Conference on Information and Communication Technologies: From Theory to Applications, 2008
In this paper a new class of adjustable window functions based on cosine hyperbolic function is p... more In this paper a new class of adjustable window functions based on cosine hyperbolic function is proposed. The proposed window, namely cosh window for short, has been derived in the same way of the derivation of Kaiser window but it has the advantage of having no power series expansion in its time domain function. The spectral characteristic of cosh window
2012 20th Signal Processing and Communications Applications Conference (SIU), 2012
Bu çalışmada kısmi destek kümesiönceden bilinen seyrek ve sıkıştırılabilir işaretlerin geri çatıl... more Bu çalışmada kısmi destek kümesiönceden bilinen seyrek ve sıkıştırılabilir işaretlerin geri çatılması için p < 1 degerli kısmi destek kümeli lp küçümseme ele alınmıştır. Seyrek işareti geri çatmak için kısmi destek kümesi bilinen lp küçümseme tabanlı yöntemönerilmiş ve geri çatmak için kısmi destek kümesi bilinen lp küçümseme metodunun gerekli şartları verilmiştir. Teorik sonuçlara göre kısmi destek kümesi bilinen lp küçümseme tabanlı metod kararlı ve dayanıklı bir yapı göstermiştir. Ayrıca numerik sonuçlara göre, lp küçümseme metodu klasik kısmi destek kümesi bilinen sıkıştırmalı algılamaya göre daha az sayıdä olçüm sayısına ihtiyaç duyarak işaretin geri çatılmasına olanak saglamıştır.
2011 IEEE 19th Signal Processing and Communications Applications Conference (SIU), 2011
Bu çalışmada seyrek bozulmuş ölçümlerden seyrek işareti geri kazanmak için alternatif bir yol ola... more Bu çalışmada seyrek bozulmuş ölçümlerden seyrek işareti geri kazanmak için alternatif bir yol olarak yinelemeli ağırlıklı en küçük kareler yöntemi (IRLS) çalışılmaktadır. Bilindiği üzere sıkıştırmalı algılama teorisi, dik bir dönüşümle seyrek olarak ifade edilebilen N boyutlu bir işaretin M<<N ölçüm kullanarak tekrar tam olarak geri kazanılabileceğini göstermiştir. l 1 minimizasyon yerine p<1 olmak kaydıyla l p minimizasyon kullanılması ölçüm sayısını daha da düşürebilir. Seyrek bozulmuş ölçümlerden işaretlerin geri kazanımı için farklı p değerleri kullanılan IRLS ve yinelemeli tekrar ağırlıklı l 1 minimizasyon simülasyon sonuçları verilmektedir. Simülasyonlardan elde edilen sonuçlara göre yinelemeli tekrar ağırlıklı l 1 minimizasyona göre daha az ölçüm sayısı tam olarak geri kazanım için yeterli gelmektedir.
2010 IEEE 18th Signal Processing and Communications Applications Conference, 2010
ABSTRACT
2008 3rd International Conference on Information and Communication Technologies: From Theory to Applications, 2008
In this study, 2-parameter cosh window is modified to improve its spectral characteristic in term... more In this study, 2-parameter cosh window is modified to improve its spectral characteristic in terms of the ripple ratio by proposing a new additional parameter. It is observed that an increase in the new parameter results in wider mainlobe width and smaller ripple ratio. By choosing the suitable combinations of the two adjustable parameters for the proposed modified window, the
2013 The International Conference on Technological Advances in Electrical, Electronics and Computer Engineering (TAEECE), 2013
In this study, a brief review of the memristor and its terminal equations are given. Biquadratic ... more In this study, a brief review of the memristor and its terminal equations are given. Biquadratic filter implementation with memristor is introduced. SPICE subcircuit model is presented to simulate the memristor. Gain and phase characteristics of the proposed biquadratic filter are obtained with SPICE circuit simulator. It is observed that filter parameter such as cut off frequencies, band width, quality factor are adjustable by memristor parameters and the power consumption of the biquadratic filter with memristor is low and has better efficiency.
Signal & Image Processing : An International Journal, 2013
In this paper we propose a new class of 2-parameter adjustable windows, namely Exponential window... more In this paper we propose a new class of 2-parameter adjustable windows, namely Exponential window, based on the exponential function [1,2]. The Exponential window is derived in the same way as Kaiser window was derived, but our proposed window is more computationally efficient because in its time domain function it has no power series expansion. First, the spectrum design equations for the Exponential window are established, and the spectral comparisons are performed with Cosh, Kaiser and ultraspherical windows. The proposed window is compared with Cosh and Kaiser windows, and the results show that for the same window length and mainlobe width the Exponential window provides better sidelobe roll-off ratio characteristic, which may be important for some applications, but worse ripple ratio. The second comparison is performed with ultraspherical window for the same window length, mainlobe width and sidelobe roll-off ratio and the results demonstrate that the Exponential window exhibits better ripple ratio for the narrower mainlobe width and larger sidelobe roll-off ratio, but worse ripple ratio for the wider mainlobe width and smaller sidelobe roll-off ratio.
2008 Ph.D. Research in Microelectronics and Electronics, 2008
In this paper a new class of adjustable windows based on the exponential function is proposed. Th... more In this paper a new class of adjustable windows based on the exponential function is proposed. The proposed window has been derived in the same way of the derivation of Kaiser window, but it has the advantage of having no power series expansion in its time domain function. The spectrum design equations for the proposed window are established, and the
Signal Processing, 2013
ABSTRACT We study recovering sparse and compressible signals using I-p minimization with p &l... more ABSTRACT We study recovering sparse and compressible signals using I-p minimization with p < 1 when some part of the support of the signal is known a priori. Sparse reconstruction method based on I-p minimization with partially known set is proposed and recovery conditions are given. Theoretical results show that I-p minimization with partially known support is stable and robust. Experimental results are presented to expose the modification of I-p minimization improves performance and need fewer samples to reconstruct the signal.
International Journal of Circuit Theory and Applications, 1993
On the basis of signal flow graphs a general method is described for the design of stray-insensit... more On the basis of signal flow graphs a general method is described for the design of stray-insensitive switched capacitor networks. To be able to choose the optimum one, the method involves the search of all possible topologies for the specially formed signal flow graph of the given z-domain transfer function and is easily implemented by digital computer. 2. FORMULATION Let the z-domain transfer function of the SC network to be designed be Consider the SFG shown in Figure I , which is a generalization of the graph given in Reference 3. Let the branches have transmittances in the forms Ki = ai + biz-', Gi = C; + diz-' where i = 1,2, ..., n; a;, b;, c; and d; are real numbers. The overall gain of this SFG can be calculated to be