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Full-Text Articles in Physical Sciences and Mathematics

Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu Jan 2010

Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

2-(4-Amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H-1,2,4-triazol- 1-yl)-N'-[(2,6-dihalogenophenyl)-methylene]acetohydrazides (3a,b) was obtained via the formation of 2-(4-amino-3-(4-chlorophenyl)-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl)acetohydrazide (2), which was obtained starting from 4-amino-5-(4-chlo\-rophenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (1) in 2 steps. 2-{[4-amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H- 1,2,4-triazol-1-yl]acetyl}-N-phenylhydra-zine carbothioamide (4), which was prepared starting from 2, was converted to the corresponding 1,3,4-thiadiazole derivative (5) in acidic media. Moreover, the basic treatment of 4 resulted in the formation of 4-amino-5-(4-chlorophenyl)- 2-[(4-phenyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl]-2,4- dihydro-3H-1,2,4-triazol-3-one (7). The reactions of compounds 5 and 7 with methyl iodide in the presence of sodium ethoxide afforded the corresponding N-methyl (6) and S-methyl (8) derivatives, respectively. The synthesis of Mannich bases (10a and 10b) was performed from the reaction of 7 with …


Preparation Of Polystyrene/Montmorillonite Nanocomposites: Optimization By Response Surface Methodology (Rsm), Sadik Erdem Yalçinkaya, Nuray Yildiz, Mehmet Saçak, Ayla Çalimli Jan 2010

Preparation Of Polystyrene/Montmorillonite Nanocomposites: Optimization By Response Surface Methodology (Rsm), Sadik Erdem Yalçinkaya, Nuray Yildiz, Mehmet Saçak, Ayla Çalimli

Turkish Journal of Chemistry

Preparation of polystyrene (PS)-montmorillonite nanocomposites was carried out in 3 steps: purification and determination of the cation exchange capacity (CEC) of clay, synthesis of organoclay, and preparation of nanocomposites. In organoclay synthesis, 3 types of surfactants, long-chained (cetyltrimethylammonium bromide (CTAB)), short-chained (tetraethylammonium bromide (TEAB)), and ringed (benzyltriethylammonium bromide (BTEAB)), were used. Gallery distances of pure clay and organoclays (CTAB-O, TEAB-O, and BTEAB-O) were determined by X-ray diffraction (XRD) analysis as 1.25, 2.09, 1.52, and 1.63 nm, respectively. Preparation of nanocomposites was carried out by in situ polymerization. Composites, containing 2%, 4%, and 6% organoclay by mass, were characterized by XRD, …


Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri Jan 2010

Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri

Turkish Journal of Chemistry

An efficient one-pot method for the synthesis of 1,4-dihydropyridines from \beta-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 °C under solvent-free conditions with good to excellent yields. The catalyst is easily prepared, stable (up to 300 °C), reusable, and efficiently used under reaction conditions.


Friedel-Crafts Acylation Of Arenes With Carboxylic Acids Using Silica Gel Supported Alcl_3, Kaveh Parvanak Jan 2010

Friedel-Crafts Acylation Of Arenes With Carboxylic Acids Using Silica Gel Supported Alcl_3, Kaveh Parvanak

Turkish Journal of Chemistry

Aromatic compounds react smoothly with carboxylic acids in the presence of silica gel supported aluminium trichloride to afford the corresponding ketones with high regioselectivity in high to excellent yields. The catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency.


Chemistry Of 2-Aminoanthraquinones, Mostafa Gouda, Moged Berghot, Alaa Shoeip, Khaled Elattar, Abd El Galil Khalil Jan 2010

Chemistry Of 2-Aminoanthraquinones, Mostafa Gouda, Moged Berghot, Alaa Shoeip, Khaled Elattar, Abd El Galil Khalil

Turkish Journal of Chemistry

This review represents a systematic and comprehensive survey of the methods of preparation and the chemical reactivity of 2-aminoanthraquinone. This compound is an important intermediate for the synthesis of a variety of otherwise difficult to obtain synthetically useful and novel heterocyclic systems.


Synthesis, Spectroscopic Characterization, Mass Spectrometry, And Crystal Structure Of N-{[(4-Bromophenyl)Amino]Carbonothioyl}Benzamide, Sohail Saeed, Naghmana Rashid, Moazzam Bhatti, Peter Jones Jan 2010

Synthesis, Spectroscopic Characterization, Mass Spectrometry, And Crystal Structure Of N-{[(4-Bromophenyl)Amino]Carbonothioyl}Benzamide, Sohail Saeed, Naghmana Rashid, Moazzam Bhatti, Peter Jones

Turkish Journal of Chemistry

N-{[(4-bromophenyl)amino]carbonothioyl}benzamide was synthesized and characterized by IR, ^1H- and ^{13}C-NMR, mass spectrometry, and elemental analysis. The crystal structure was determined from single crystal X-ray diffraction data. It crystallizes in monoclinic space group P2_1/n with unit cell dimensions a = 13.822(3) Å, b = 5.927(2) Å, c = 16.642(3) Å, and \beta = 103.963(3)°. There is a strong intramolecular hydrogen bond of the type N__H \Lambda O, with an H\Lambda O distance of 2.6129 (11) Å. The mass fragmentation pattern is also discussed.


Adaptive Neuro-Fuzzy Inference System To Improve The Power Quality Of Variable-Speed Wind Power Generation System, Yüksel Oğuz, Kami̇l Ri̇fat İrfan Güney Jan 2010

Adaptive Neuro-Fuzzy Inference System To Improve The Power Quality Of Variable-Speed Wind Power Generation System, Yüksel Oğuz, Kami̇l Ri̇fat İrfan Güney

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an adaptive neuro-fuzzy inference system is designed for output voltage and frequency control of a variable-speed wind power generation system. Variable-speed wind power generation systems (VSWPGS) provide the opportunity to capture more power than fixed speed turbines. On the other hand, the variable-speed wind turbine output can be variable voltage and variable frequency for fluctuating wind speeds. The quality of output power can be improved if adequate controls are incorporated in the system. To bring the output voltage and frequency of system by means of control of blade pitch angle of wind turbine to a desirable value, …


Finite Subquandles Of Sphere, Nüli̇fer Özdemi̇r, Hüseyi̇n Azcan Jan 2010

Finite Subquandles Of Sphere, Nüli̇fer Özdemi̇r, Hüseyi̇n Azcan

Turkish Journal of Mathematics

In this work finite subquandles of sphere are classified by using classification of subgroups of orthogonal group O(3). For any subquandle Q of sphere there is a subgroup G_Q of O(3) associated with Q. It is shown that if Q is a finite (infinite) subquandle, then G_Q is a finite (infinite) subgroup. Finite subquandles of sphere are obtained from actions of finite subgroups of SO(3) on sphere. It is proved that the finite subquandles Q_1 and Q_2 of sphere whose all elements are not on the same great circle are isomorphic if and only if the subgroups G_{Q_1} and G_{Q_2} …


Effect Of Substrate Temperature On The Optical Properties Of Thermally Evaporated Zns Thin Films, M. Ruhul Amin Bhuiyan, M. Monjarul Alam, M. Abdul Momin Jan 2010

Effect Of Substrate Temperature On The Optical Properties Of Thermally Evaporated Zns Thin Films, M. Ruhul Amin Bhuiyan, M. Monjarul Alam, M. Abdul Momin

Turkish Journal of Physics

Zinc Sulfide (ZnS) thin films were formed onto cleaned glass substrates using the thermal evaporation method in vacuum. The substrate temperature was varied between as- deposited and 150 °C, keeping the film thickness and the rate of evaporation fixed at 200~nm and 0.3~nm \cdot s^{-1}, respectively. The film thickness was measured in situ by a quartz crystal thickness monitor. The structure of the films was ascertained by x-ray diffraction (XRD) method. The XRD spectra show that the films are polycrystalline in nature, which possess hexagonal structure. The optical properties of the films were ascertained by UV-VIS-NIR spectrophotometer (photon wavelength ranging …


Electron Paramagnetic Resonance Study Of Vo^{2+} Doped Single Crystal Of Ferroelectric Guanidinium Uranyl Sulphate Trihydrate, Mohammad Imtiazul Haque, Mohammad Umar Jan 2010

Electron Paramagnetic Resonance Study Of Vo^{2+} Doped Single Crystal Of Ferroelectric Guanidinium Uranyl Sulphate Trihydrate, Mohammad Imtiazul Haque, Mohammad Umar

Turkish Journal of Physics

We report result obtained from an EPR study of vanadyl ion (VO^{2+}) in a single crystal of ferroelectric guanidinium uranyl sulphate trihydrate. The Spin-Hamiltonian parameters were also determined via EPR data. VO^{2+} enters the lattice interstitially at two distinguishable sites and resulting vanadyl complexes have nearly axial symmetry.


A Case Study On \Sigma \Lambda Conversion In P-Shell Hypernuclei, Masroor Bukhari Jan 2010

A Case Study On \Sigma \Lambda Conversion In P-Shell Hypernuclei, Masroor Bukhari

Turkish Journal of Physics

The important process of \Sigma-\Lambda conversion is presented and discussed in this report and a case example has been presented reviewing some cross sections and decay widths calculated for the process in a p-shell hypernucleus in recent studies.


Exact Solutions For The Double Sinh-Gordon And Generalized Form Of The Double Sinh-Gordon Equations By Using (G'/G)-Expansion Method, Hossein Kheiri, Azizeh Jabbari Jan 2010

Exact Solutions For The Double Sinh-Gordon And Generalized Form Of The Double Sinh-Gordon Equations By Using (G'/G)-Expansion Method, Hossein Kheiri, Azizeh Jabbari

Turkish Journal of Physics

In this paper, the (G'/G)-expansion method is applied to seek traveling wave solutions to the double sinh-Gordon and the generalized form of the double sinh-Gordon equations. With the aid of a symbolic computation system, two types of more general traveling wave solutions (including hyperbolic functions and trigonometric functions) with free parameters are constructed. Solutions concerning solitary and periodic waves are also given by setting the two arbitrary parameters, involved in the traveling waves, as special values.


Influence Of The Nitrogen Concentration On The Electrical Characteristic Of Hydrogenated Amorphous Silicon Nitride (A-Sin_X:H) Based Schottky Diodes, İlker Ay, Hüseyi̇n Tolunay Jan 2010

Influence Of The Nitrogen Concentration On The Electrical Characteristic Of Hydrogenated Amorphous Silicon Nitride (A-Sin_X:H) Based Schottky Diodes, İlker Ay, Hüseyi̇n Tolunay

Turkish Journal of Physics

In this study, the Schottky diode characteristic of hydrogenated amorphous silicon nitride (a-SiN_x:H) samples containing various amounts of nitrogen have been investigated via both I-V and C-V measurements. From forward bias I-V measurements in the dark, the barrier height of samples (\phi_{B0}), ideality factor (\eta ), modified Richardson constant (A^\ast) and series resistances (R_s) have been obtained as the function of temperature for different nitrogen content. In addition, forward and reverse bias current ratios (I_f/I_r) at V~=~1 volt have been investigated as the function of temperature for different nitrogen content. Light sensitivity of the samples has also been investigated under …


Photocurrent And Surface Recombination Mechanisms In The In_Xga_{1-X}N\Slashgan Different-Sized Quantum Dot Solar Cells, Hossein Movla, Foozieh Sohrabi, Jafar Fathi, Hassan Babaei, Arash Nikniazi, Khadije Khalili, Nima Es'haghi Gorji Jan 2010

Photocurrent And Surface Recombination Mechanisms In The In_Xga_{1-X}N\Slashgan Different-Sized Quantum Dot Solar Cells, Hossein Movla, Foozieh Sohrabi, Jafar Fathi, Hassan Babaei, Arash Nikniazi, Khadije Khalili, Nima Es'haghi Gorji

Turkish Journal of Physics

We present a p-i-n structured solar cell with stacked layers of In_xGa_{1-x}N Quantum Dots (QDs) with different indium composition. The photocurrent and surface recombination processes are investigated in the i-region. We have shown that the QDs in the i-region can play the role of both generation or recombination centers. The photocurrent has been calculated by self-consistent method to solve continuity equation of charge carriers in the layers of the i-region. By changing the Indium composition in In_xGa_{1-x}N QDs, the band gap of QDs varies and therefore provides a considerable overlapping with solar spectrum. Proposed SC with different-sized QDs and different …


Effects Of Deformation Ratio On The Mechanical Properties And Microstructures Changes In An Al-Mg-Si Alloy, Hichem Farh, Rebai Guemini, Serradj Fares, Karim Djemmal Jan 2010

Effects Of Deformation Ratio On The Mechanical Properties And Microstructures Changes In An Al-Mg-Si Alloy, Hichem Farh, Rebai Guemini, Serradj Fares, Karim Djemmal

Turkish Journal of Physics

An investigation has been done to study the effect of deformation ratio and two-step ageing treatment on the microstructure and the mechanical properties in an Al-Mg-Si aluminum alloy. Transmission electron microscopy is used in order to follow the distribution and the morphology of the hardening precipitates. The hardness of the alloy increases with the increasing deformation ratio. The maximum of hardness increases and is shifted to low time with an increase of the deformation ratio. The density of precipitates is more increased and the precipitates become more inhomogeneously distributed when the deformation combines with two-step ageing treatments.


Vibration Spectra Of Polar Mixing Optical Phonon States And Fröhlich Electron-Phonon Coupling Behaviors In A Wurtzite Zno Quantum Dot, Li Zhang Jan 2010

Vibration Spectra Of Polar Mixing Optical Phonon States And Fröhlich Electron-Phonon Coupling Behaviors In A Wurtzite Zno Quantum Dot, Li Zhang

Turkish Journal of Physics

Based on the dielectric continuum model and Loudon's uniaxial crystal model, the interface-optical-propagating (IO-PR) mixing phonon states of a quasi-zero-dimensional (Q0D) wurtzite cylindrical quantum dot (QD) are investigated. It is found that there are two types of IO-PR mixing phonon modes, i.e. \rho-IO/z-PR mixing modes and the z-IO/\rho-PR mixing modes coexisting in Q0D wurtzite QDs. Numerical calculation on a wurtzite ZnO QD shows that the dispersion frequencies of the mixing modes are discrete functions of the azimuthal quantum number and axial wave-number. The calculated results agree well with the recent experimental spectra in ZnO QDs. An abnormal electron-phonon coupling strength …


Inept Nmr Spectroscopy Of ^{14}Nd_N Groups: Product Operator Theory And Simulation, Deni̇z Türkpençe, İrfan Şaka, Azmi̇ Gençten Jan 2010

Inept Nmr Spectroscopy Of ^{14}Nd_N Groups: Product Operator Theory And Simulation, Deni̇z Türkpençe, İrfan Şaka, Azmi̇ Gençten

Turkish Journal of Physics

Product operator formalism is widely used for the analytical description of multi-dimensional and multiple-pulse NMR experiments for the weakly coupled spin systems having spin-1/2 and spin-1 nuclei. The INEPT NMR experiment is a polarization transfer experiment including J-coupling. In this study, the INEPT NMR experiment was analytically investigated by using product operator theory for weakly coupled IS_n(^{14}ND_n) (I=1, S=1; n=1, 2, 3) spin systems. The obtained theoretical results represent the FID values of ^{14}ND_n groups. In order to make Fourier transform of the obtained FID values, a Maple program is used and then simulated spectra of the INEPT experiment are …


On The S-Wave Jost Solution For Coulomb-Distorted Nuclear Potential, Ujjwal Laha, Bibekananda Kundu Jan 2010

On The S-Wave Jost Solution For Coulomb-Distorted Nuclear Potential, Ujjwal Laha, Bibekananda Kundu

Turkish Journal of Physics

A closed form expression of the off-shell Jost solution for Coulomb plus separable nuclear potential is derived using interacting Green's functions and their integral transforms. As an application of our result the off-shell Jost function for the proton-proton scattering in the ^1S_0 channel is computed for various laboratory energies to investigate the role of long range Coulomb interaction in off-shell scattering.


On Robertson-Walker Universe Model With Variable Cosmological Term And Gravitational Constant In Cosmological Relativity Theory, Kangujam Priyokumar Singh Jan 2010

On Robertson-Walker Universe Model With Variable Cosmological Term And Gravitational Constant In Cosmological Relativity Theory, Kangujam Priyokumar Singh

Turkish Journal of Physics

This paper presents cosmological models in which the gravitational and cosmological constants G and \Lambda are time-dependent. We find a variety of solutions for the variation of cosmological parameters. It is also found that, in the case of matter dominated Robertson-Walker Universe, if the cosmological constant \Lambda \ne 0, the Hubble's constant H is not constant at all but inversely proportional to the cosmic time. The conservation law for the energy momentum tensor is still valid with our law of variation: \Lambda \propto R^{-2} and G\rho \propto \frac{\Lambda }{8\pi}.


Korovkin Type Approximation Theorem For Functions Of Two Variables In Statistical Sense, Fadi̇me Di̇ri̇k, Kami̇l Demi̇rci̇ Jan 2010

Korovkin Type Approximation Theorem For Functions Of Two Variables In Statistical Sense, Fadi̇me Di̇ri̇k, Kami̇l Demi̇rci̇

Turkish Journal of Mathematics

In this paper, using the concept of A-statistical convergence for double sequences, we investigate a Korovkin-type approximation theorem for sequences of positive linear operator on the space of all continuous real valued functions defined on any compact subset of the real two-dimensional space. Then we display an application which shows that our new result is stronger than its classical version. We also obtain a Voronovskaya-type theorem \ and some differential properties for sequences of positive linear operators constructed by means of the Bernstein polynomials of two variables.


Extremal Lagrangian Submanifolds In A Complex Space Form N^N(4c), Shichang Shu, Annie Yi Han Jan 2010

Extremal Lagrangian Submanifolds In A Complex Space Form N^N(4c), Shichang Shu, Annie Yi Han

Turkish Journal of Mathematics

Let N^n(4c) be the complex space form of constant holomorphic sectional curvature 4c, \varphi: M \to N^n(4c) be an immersion of an n-dimensional Lagrangian manifold M in N^n(4c). Denote by S and H the square of the length of the second fundamental form and the mean curvature of M. Let \rho be the non-negative function on M defined by \rho^2=S-nH^2, Q be the function which assigns to each point of M the infimum of the Ricci curvature at the point. In this paper, we consider the variational problem for non-negative functional U(\varphi)=\int_M\rho^2dv=\int_M(S-nH^2)dv. We call the critical points of U(\varphi) the …


A Note On The Lyapunov Exponent In Continued Fraction Expansions, Jianzhong Cheng, Lu-Ming Shen Jan 2010

A Note On The Lyapunov Exponent In Continued Fraction Expansions, Jianzhong Cheng, Lu-Ming Shen

Turkish Journal of Mathematics

Let T:[0,1) \to [0,1) be the Gauss transformation. For any irrational x \in [0,1), the Lyapunov exponent \alpha(x) of x is defined as \alpha(x)=\lim_{n\to\infty}\frac{1}{n} \log (T^n)'(x) . By Birkoff Average Theorem, one knows that \alpha(x) exists almost surely. However, in this paper, we will see that the non-typical set \{x\in [0,1):\lim_{n\to\infty}\frac{1}{n} \log (T^n)'(x) does not exist\} carries full Hausdorff dimension.


On The Codifferential Of The Kähler Form And Cosymplectic Metrics On Maximal Flag Manifolds, Marlio Paredes, Sofia Pinzon Jan 2010

On The Codifferential Of The Kähler Form And Cosymplectic Metrics On Maximal Flag Manifolds, Marlio Paredes, Sofia Pinzon

Turkish Journal of Mathematics

Using moving frames we obtain a formula to calculate the codifferential of the Kähler form on a maximal flag manifold. We use this formula to obtain some differential type conditions so that a metric on the classical maximal flag manifold be cosymplectic.


Generalized Fibonacci Sequences Related To The Extended Hecke Groups And An Application To The Extended Modular Group, Özden Koruoğlu, Recep Şahi̇n Jan 2010

Generalized Fibonacci Sequences Related To The Extended Hecke Groups And An Application To The Extended Modular Group, Özden Koruoğlu, Recep Şahi̇n

Turkish Journal of Mathematics

The extended Hecke groups \overline{H}(\lambda _{q}) are generated by T(z)=-1/z, S(z)=-1/(z+\lambda _{q}) and R(z)=1/ \overline{z} with \lambda _{q}=2\cos (\pi /q) for q\geq 3 integer. In this paper, we obtain a sequence which is a generalized version of the Fibonacci sequence given in [6] for the extended modular group \overline{\Gamma }, in the extended Hecke groups \overline{H}(\lambda_{q}). Then we apply our results to \overline{\Gamma } to find all elements of the extended modular group \overline{\Gamma }.


On The Qualitative Analysis Of The Uniqueness Of The Movement Of Endothelial Cells, Erdem Altuntaç, Serdal Pamuk Jan 2010

On The Qualitative Analysis Of The Uniqueness Of The Movement Of Endothelial Cells, Erdem Altuntaç, Serdal Pamuk

Turkish Journal of Mathematics

This paper extends the work of Pamuk (2003) by showing mathematically that the movement of endothelial cells, to the regions where active enzyme is large or where fibronectin is small, is unique. To do this, we obtain the existence and uniqueness of the steady-state solution of an initial-boundary value problem which mathematically models endothelial cell movement in tumor angiogenesis. A specific example showing the instability of this steady-state solution is provided.


Swan Conductors And Torsion In The Logarithmic De Rham Complex, Si̇nan Ünver Jan 2010

Swan Conductors And Torsion In The Logarithmic De Rham Complex, Si̇nan Ünver

Turkish Journal of Mathematics

We prove, for an arithmetic scheme X/S over a discrete valuation ring whose special fiber is a strict normal crossings divisor in X, that the Swan conductor of X/S is equal to the Euler characteristic of the torsion in the logarithmic de Rham complex of X/S. This is a precise logarithmic analog of a theorem by Bloch [1].


Pseudo Simplicial Groups And Crossed Modules, İlker Akça, Sedat Pak Jan 2010

Pseudo Simplicial Groups And Crossed Modules, İlker Akça, Sedat Pak

Turkish Journal of Mathematics

In this paper, we define the notion of pseudo 2-crossed module and give a relation between the pseudo 2-crossed modules and pseudo simplicial groups with Moore complex of length 2.


Comparison Of Daubechies Wavelets For Hurst Parameter Estimation, Cebrai̇l Çi̇ftli̇kli̇, Ali̇ Gezer Jan 2010

Comparison Of Daubechies Wavelets For Hurst Parameter Estimation, Cebrai̇l Çi̇ftli̇kli̇, Ali̇ Gezer

Turkish Journal of Electrical Engineering and Computer Sciences

Time scale dependence on the working nature of wavelet analysis makes it a valuable tool for Hurst parameter estimation. Similar to other wavelet-based signal processing applications, the selection of a particular wavelet type and vanishing moment in wavelet based Hurst estimation is a challenging problem. In this paper, we investigate the best Daubechies wavelet in wavelet based Hurst estimation for an exact self similar process, fractional Gaussian noise and how Daubechies vanishing moment affects the Hurst estimation accuracy. Daubechies wavelets are preferred in analysis because increasing vanishing moment does not cause excessive increase of time support of Daubechies wavelets. Thus, …


Performance Analysis Of Swarm Optimization Approaches For The Generalized Assignment Problem In Multi-Target Tracking Applications, Ali̇ Önder Bozdoğan, Asim Egemen Yilmaz, Murat Efe Jan 2010

Performance Analysis Of Swarm Optimization Approaches For The Generalized Assignment Problem In Multi-Target Tracking Applications, Ali̇ Önder Bozdoğan, Asim Egemen Yilmaz, Murat Efe

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to investigate the suitability of selected swarm optimization algorithms to the generalized assignment problem as encountered in multi-target tracking applications. For this purpose, we have tested variants of particle swarm optimization and ant colony optimization algorithms to solve the 2D generalized assignment problem with simulated dense and sparse measurement/track matrices and compared their performance to that of the auction algorithm. We observed that, although with some modification swarm optimization algorithms provide improvement in terms of speed, they still fall behind the auction algorithm in finding the optimum solution to the problem. Among the investigated …


On Orders And Types Of Dirichlet Series Of Slow Growth, Yinying Kong, Huilin Gan Jan 2010

On Orders And Types Of Dirichlet Series Of Slow Growth, Yinying Kong, Huilin Gan

Turkish Journal of Mathematics

The present paper has the object of showing some interesting relationship on the maximum modulus, the maximum term, the index of maximum term and the coefficients of entire functions defined by Dirichlet series of slow growth; some properties like Taylor entire functions are obtained.