Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Turkey (105)
- 1 (99)
- 2 (82)
- Classification (70)
- Optimization (65)
-
- Deep learning (61)
- Genetic algorithm (61)
- Machine learning (61)
- Synthesis (61)
- Adsorption (53)
- Particle swarm optimization (51)
- Antimicrobial activity (47)
- Geochemistry (47)
- 3 (44)
- Stability (39)
- Artificial neural network (37)
- Phthalocyanine (35)
- Support vector machine (34)
- Feature extraction (32)
- Wireless sensor networks (31)
- Antibacterial activity (29)
- Artificial neural networks (28)
- Feature selection (28)
- Copper (27)
- Cytotoxicity (27)
- Power quality (27)
- Fuzzy logic (26)
- Molecular docking (26)
- Palladium (26)
- Preconcentration (26)
- Publication Year
Articles 6211 - 6240 of 10319
Full-Text Articles in Physical Sciences and Mathematics
New Trace Formula For The Matrix Sturm-Liouville Equation With Eigenparameter Dependent Boundary Conditions, Chuan Fu Yang
New Trace Formula For The Matrix Sturm-Liouville Equation With Eigenparameter Dependent Boundary Conditions, Chuan Fu Yang
Turkish Journal of Mathematics
A regularized trace formula of first order for the matrix Sturm-Liouville equation with eigenparameter in the boundary conditions is obtained.
Finite Rings And Wilson's Theorem, Yasuyuki Hirano, Manabu Matsuoka
Finite Rings And Wilson's Theorem, Yasuyuki Hirano, Manabu Matsuoka
Turkish Journal of Mathematics
In this paper we consider the product of all elements in the group of units in a finite ring and we generalize Wilson's theorem to finite rings. As an application, we study some generalizations of Wilson's theorem on residually finite Dedekind domains. And we also give some examples for such rings. Moreover we study some generalizations of Wilson's theorem on rings of matrices over a finite commutative ring.
On Theta Pair For A Proper Subalgebra, Ali Reza Salemkar, Sara Chehrazi, Hamid Mohammadzadeh
On Theta Pair For A Proper Subalgebra, Ali Reza Salemkar, Sara Chehrazi, Hamid Mohammadzadeh
Turkish Journal of Mathematics
For a proper subalgebra K of a finite dimensional Lie algebra L, a pair (A,B) of subalgebras of L is called a \theta-pair if L = \langle A,K\rangle, B is the largest ideal of L contained in A\cap K and for each proper subalgebra C/B of A/B which is an ideal of L/B, we have L\neq C+K. In this article, using this concept, we give some characterizations of solvability and supersolvability of a finite dimensional Lie algebra.
On Integrability Of Golden Riemannian Structures, Aydin Gezer, Nejmi̇ Cengi̇z, Arif Salimov
On Integrability Of Golden Riemannian Structures, Aydin Gezer, Nejmi̇ Cengi̇z, Arif Salimov
Turkish Journal of Mathematics
The main purpose of the present paper is to study the geometry of Riemannian manifolds endowed with Golden structures. We discuss the problem of integrability for Golden Riemannian structures by using a \phi-operator which is applied to pure tensor fields. Also, the curvature properties for Golden Riemannian metrics and some properties of twin Golden Riemannian metrics are investigated. Finally, some examples are presented.
L^P Solutions Of Infinite Time Interval Bsdes And The Corresponding G-Expectations And G-Martingales, Zhaojun Zong
L^P Solutions Of Infinite Time Interval Bsdes And The Corresponding G-Expectations And G-Martingales, Zhaojun Zong
Turkish Journal of Mathematics
In this paper we study the existence and uniqueness theorem for L^p (1
A Time--Memory Trade-Off Approach For The Solution Of Nonlinear Equation Systems, Hüseyi̇n Demi̇rci̇, Mahmut Şami̇l Sağiroğlu, Muhammed Oğuzhan Külekci̇
A Time--Memory Trade-Off Approach For The Solution Of Nonlinear Equation Systems, Hüseyi̇n Demi̇rci̇, Mahmut Şami̇l Sağiroğlu, Muhammed Oğuzhan Külekci̇
Turkish Journal of Electrical Engineering and Computer Sciences
We propose a memory-based method for the solution of a specific type of nonlinear equation systems. We observe that when the equations in a system can be separated into 2 parts, where each subset contains fewer parameters than the whole set of equations, the system can be solved faster with a preprocessing phase. We show that reduced rounds of AES produce such a system under a chosen plaintext scenario. This observation enables us to solve that system within a practically applicable complexity of 2^{37} operations where a brute force approach requires 2^{72} trials. The method can be used for the …
End-To-End Transmission Time-Based Opportunistic Routing Protocols For Bus Networks, Luobei Kuang, Zhijun Wang, Ming Xu, Yingwen Cheng
End-To-End Transmission Time-Based Opportunistic Routing Protocols For Bus Networks, Luobei Kuang, Zhijun Wang, Ming Xu, Yingwen Cheng
Turkish Journal of Electrical Engineering and Computer Sciences
Single path routing protocols for Internet access in bus networks (composed of traveling city public buses) may not achieve satisfactory performance because of frequent bus mobility. This paper studies the opportunistic routing protocols in bus networks to improve the system throughput and reduce the access delay. In this paper, we first propose an end-to-end transmission time (EET)-based opportunistic routing (OR) framework. We then derive 3 EET-based OR protocols, EETOR (EET-based OR), EETMcOR (EET-based OR with MAC contention consideration), and EETCcOR (EET-based OR with congestion control consideration), which consider 3 different EET metrics. EETOR considers the network layer transmission behavior to …
Simulation Of A Large Electric Distribution System Having Intensive Harmonics In The Industrial Zone Of Konya, Hasan Eroğlu, Musa Aydin
Simulation Of A Large Electric Distribution System Having Intensive Harmonics In The Industrial Zone Of Konya, Hasan Eroğlu, Musa Aydin
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, measurements were taken at different points of a sample distribution system in order to analyze the levels of harmonics that appear as a day-to-day increasing problem in electrical distribution systems. According to the measurement values, the dominant harmonics have been determined and an electrical model of the system has been prepared using the SimPowerSystems toolbox from MATLAB and Simulink. The accuracy of the electrical model has been verified by the measurement and simulation values. In addition, the transformer connection types' and impedances' simulations have been presented to understand and solve the harmonic problems in electrical distribution systems. …
Actor-Critic-Based Ink Drop Spread As An Intelligent Controller, Hesam Sagha, Iman Esmaili Paeen Afrakoti, Saeed Bagherishouraki
Actor-Critic-Based Ink Drop Spread As An Intelligent Controller, Hesam Sagha, Iman Esmaili Paeen Afrakoti, Saeed Bagherishouraki
Turkish Journal of Electrical Engineering and Computer Sciences
This paper introduces an innovative adaptive controller based on the actor-critic method. The proposed approach employs the ink drop spread (IDS) method as its main engine. The IDS method is a new trend in soft-computing approaches that is a universal fuzzy modeling technique and has been also used as a supervised controller. Its process is very similar to the processing system of the human brain. The proposed actor-critic method uses an IDS structure as an actor and a 2-dimensional plane, representing control variable states, as a critic that estimates the lifetime goodness of each state. This method is fast, simple, …
Linear Switched Reluctance Motor Control With Pic18f452 Microcontroller, Mahi̇r Dursun, Fatmagül Koç
Linear Switched Reluctance Motor Control With Pic18f452 Microcontroller, Mahi̇r Dursun, Fatmagül Koç
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents the simulation, control, and experimental results of the velocity of a double-sided, 6/4-poled, 3-phased, 8 A, 24 V, 250 W, and 250 N pull force linear switched reluctance motor (LSRM). In the simulation and experimental study, the reference velocity is constant depending on the position and time. The velocity versus the position of the translator was controlled with fuzzy logic control (FLC) and proportional-integral (PI) control techniques. The motor was controlled by PI control method with a PIC18F452 microcontroller due to its low cost. The results of the velocity of a translator were compared with the simulation …
A 5-Bit 5 Gs/S Flash Adc Using Multiplexer-Based Decoder, Oktay Aytar, Ali̇ Tangel, Kudret Şahi̇n
A 5-Bit 5 Gs/S Flash Adc Using Multiplexer-Based Decoder, Oktay Aytar, Ali̇ Tangel, Kudret Şahi̇n
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a 5-bit flash analog-to-digital converter design using the 0.18-\mu m Taiwan Semiconductor Manufacturing Company's CMOS technology library. The designed system consists of 2 main blocks, a comparator array, and a digital decoder. The digital decoder contains a latch, 1-of-N decoder, and fat-tree encoder units. The 1-of-N decoder is implemented using 2 \times 1 multiplexers. As a result, the active die area and the power consumption are reduced, in addition to an increase in the sampling frequency. The power supply voltage range for the overall system is \pm 0.9 V. For testing purposes, a ramp signal of between …
Detection Of Microcalcification Clusters In Digitized X-Ray Mammograms Using Unsharp Masking And Image Statistics, Peli̇n Kuş, İrfan Karagöz
Detection Of Microcalcification Clusters In Digitized X-Ray Mammograms Using Unsharp Masking And Image Statistics, Peli̇n Kuş, İrfan Karagöz
Turkish Journal of Electrical Engineering and Computer Sciences
A fully automated method for detecting microcalcification (MC) clusters in regions of interest (ROIs) extracted from digitized X-ray mammograms is proposed. In the first stage, an unsharp masking is used to perform the contrast enhancement of the MCs. In the second stage, the ROIs are decomposed into a 2-level contourlet representation and the reconstruction is obtained by eliminating the low-frequency subband in the second level. In the third stage, statistical textural features are extracted from the ROIs and they are classified using support vector machines. To test the performance of the method, 57 ROIs selected from the Mammographic Image Analysis …
Complex Symplectic Geometry With Applications To Vector Differential Operators, Chuan Fu Yang
Complex Symplectic Geometry With Applications To Vector Differential Operators, Chuan Fu Yang
Turkish Journal of Mathematics
Let l(y) be a formally self-adjoint vector-valued differential expression of order n on an interval (a, \infty)(-\infty \leq a < \infty) with complex matrix-valued function coefficients and finite equal deficiency indices. In this paper, applying complex symplectic algebra, we give a reformulation for self-adjoint domains of the minimal operator associated with l(y) and classify them.
Foliations And A Class Of Metrics On Tangent Bundle, Esmaeil Peyghan, Leila Nourmohammadi Far
Foliations And A Class Of Metrics On Tangent Bundle, Esmaeil Peyghan, Leila Nourmohammadi Far
Turkish Journal of Mathematics
Let M be a smooth manifold with Finsler metric F, and let TM° be the slit tangent bundle of M with a generalized Riemannian metric G, which is induced by F. In this paper, we extract many natural foliations of (TM°,G) and study some of their geometric properties. Next we use this approach to obtain new characterizations of Finsler manifolds with positive constant curvature.
Approximation By Iterates Of Beta Operators, Purshottam Narain Agrawal, Karunesh Kumar Singh, Vikas Kumar Mishra
Approximation By Iterates Of Beta Operators, Purshottam Narain Agrawal, Karunesh Kumar Singh, Vikas Kumar Mishra
Turkish Journal of Mathematics
In this paper, we study the degree of approximation by an iterative combination T_{n,k} of the beta operators introduced by Upreti [8].
Generalized Sobolev-Shubin Spaces, Boundedness And Schatten Class Properties Of Toeplitz Operators, Ayşe Sandikçi, Ahmet Turan Gürkanli
Generalized Sobolev-Shubin Spaces, Boundedness And Schatten Class Properties Of Toeplitz Operators, Ayşe Sandikçi, Ahmet Turan Gürkanli
Turkish Journal of Mathematics
Let w and \omega be two weight functions on R^{2d} and 1 \leq p,q \leq \infty. Also let M(p,q,\omega) (R^d) denote the subspace of tempered distributions S' (R^d) consisting of f \in S' (R^d) such that the Gabor transform V_g f of f is in the weighted Lorentz space L(p,q,\omega d\mu) (R^{2d}) . In the present paper we define a space Q_{g,w}^{M(p,q,\omega) (R^d) as counter image of M(p,q,\omega) (R^d) under Toeplitz operator with symbol w. We show that Q_{g,w}^{M(p,q,\omega)}(R^d) is a generalization of usual Sobolev-Shubin space Q_s (R^d). We also investigate the boundedness and Schatten-class properties of Toeplitz operators.
Isoclinic Extensions Of Lie Algebras, Hamid Mohammadzadeh, Ali Reza Salemkar, Zahra Riyahi
Isoclinic Extensions Of Lie Algebras, Hamid Mohammadzadeh, Ali Reza Salemkar, Zahra Riyahi
Turkish Journal of Mathematics
In this article we introduce the notion of the equivalence relation, isoclinism, on the central extensions of Lie algebras, and determine all central extensions occurring in an isoclinism class of a given central extension. We also show that under some conditions, the concepts of isoclinism and isomorphism between the central extensions of finite dimensional Lie algebras are identical. Finally, the connection between isoclinic extensions and the Schur multiplier of Lie algebras are discussed.
Recombination Mechanisms In Hydrogenated Silicon Nanocrystalline Thin Films, Zaki M. Saleh, Salam M. Kmail, Samah F. Assaf, Atif F. Qasrawi
Recombination Mechanisms In Hydrogenated Silicon Nanocrystalline Thin Films, Zaki M. Saleh, Salam M. Kmail, Samah F. Assaf, Atif F. Qasrawi
Turkish Journal of Physics
The photoconductivity dependences on temperature and illumination intensity were investigated for thin films of hydrogenated nanocrystalline silicon (nc-Si:H) grown by very-high-frequency, plasma-enhanced chemical vapor deposition. The nanocrystalline phase was achieved by heavy hydrogen dilution of silane (SiH_4). We find that the activation energy of the photoconductivity is sensitive to the incident illumination intensity for illumination intensities below 6 mW/cm^2. The photocurrent follows a power-law dependence on illumination intensity (I_{ph}\propto F^{gamma}), with gamma ranging from 0.36 to 0.83. The illumination dependence of the photocurrent suggests 2 different recombination mechanisms depending on temperature. In the lower temperature regime (300-340 K), recombination appears …
Erratum To: ``Null Mannheim Curves In The Minkowski 3-Space E_1^3'', Handan Özteki̇n, Mahmut Ergüt
Erratum To: ``Null Mannheim Curves In The Minkowski 3-Space E_1^3'', Handan Özteki̇n, Mahmut Ergüt
Turkish Journal of Mathematics
In this paper, Theorem 3.2 and Proposition 3.2 in the paper which is cited in the title are corrected.
A New Color Image Quality Measure Based On Yuv Transformation And Psnr For Human Vision System, Yildiray Yalman, İsmai̇l Ertürk
A New Color Image Quality Measure Based On Yuv Transformation And Psnr For Human Vision System, Yildiray Yalman, İsmai̇l Ertürk
Turkish Journal of Electrical Engineering and Computer Sciences
Various methods for measuring perceptual image quality attempt to quantify the visibility of differences between an original digital image and its distorted version using a variety of known properties of the human vision system (HVS). In this paper, we propose a simple and effective full-reference color image quality measure (CQM) based on reversible luminance and chrominance (YUV) color transformation and peak signal-to-noise ratio (PSNR) measure. The main motivation of this new measure relies on a unique feature of the human eye response to the luminance and color. Experimental studies about the applicability of the CQM on a well-known test image …
Commutants And Hyper-Reflexivity Of Multiplication Operators, Masoumeh Faghih Ahmadi, Karim Hedayatian
Commutants And Hyper-Reflexivity Of Multiplication Operators, Masoumeh Faghih Ahmadi, Karim Hedayatian
Turkish Journal of Mathematics
We characterize the commutants of some multiplication operators on a Banach space of analytic functions defined on a bounded domain in the plane. Under certain conditions on the symbol of a multiplication operator, we show that its commutant is a set of multiplication operators. This partially answers a question of Axler, Cuckovic and Rao. Next, the hyper-reflexivity of these multiplication operators are proved. The paper is concluded by proving the hyper-reflexivity of the multiplication operators with symbols \varphi (z) = z^k, k=1, 2,... .
Cartan Equivalence Problem For Third-Order Differential Operators, Mehdi Nadjafikhah, Rohollah Bakhshandeh Chamazkoti
Cartan Equivalence Problem For Third-Order Differential Operators, Mehdi Nadjafikhah, Rohollah Bakhshandeh Chamazkoti
Turkish Journal of Mathematics
This article is dedicated to solving the equivalence problem for a pair of third-order differential operators on the line under general fiber-preserving transformation using the Cartan method of equivalence. We will treat 2 versions of equivalence problems: first, the direct equivalence problem, and second, an equivalence problem to determine conditions on 2 differential operators such that there exists a fiber-preserving transformation mapping one to the other according to gauge equivalence.
Colombeau Solutions Of A Nonlinear Stochastic Predator--Prey Equation, Uluğ Çapar
Colombeau Solutions Of A Nonlinear Stochastic Predator--Prey Equation, Uluğ Çapar
Turkish Journal of Mathematics
The solution of a random semilinear hyperbolic system with singular initial data is sought as a random Colombeau distribution. The product of 2 additive white noises is well tackled within the theory of random Colombeau distributions. In the special case of a random predator--prey system, the exact Colombeau solution is obtained under some assumptions when the process is driven by doubly reflected Brownian motions.
Remarks On The Paper ``On Some New Inequalities For Convex Functions\\" By M. Tunç, Alfred Witkowski
Remarks On The Paper ``On Some New Inequalities For Convex Functions\\" By M. Tunç, Alfred Witkowski
Turkish Journal of Mathematics
In this note, we slightly generalize Theorem 2 in the paper by M. Tunç and point out that the assumption of Theorem 3 is not sufficient. A misuse of the term 'mean' is also discussed.
A Scheme Over Prime Spectrum Of Modules, Ahmad Abbasi, Dawood Hassanzadeh Lelekami
A Scheme Over Prime Spectrum Of Modules, Ahmad Abbasi, Dawood Hassanzadeh Lelekami
Turkish Journal of Mathematics
Let R be a commutative ring with nonzero identity and let M be an R-module with X=Spec(M). It is introduced a scheme O_X on the prime spectrum of M and some of its properties have been investigated.
On Quasiconformal Harmonic Mappings Lifting To Minimal Surfaces, Hakan Mete Taştan, Yaşar Polatoğlu
On Quasiconformal Harmonic Mappings Lifting To Minimal Surfaces, Hakan Mete Taştan, Yaşar Polatoğlu
Turkish Journal of Mathematics
We prove a growth theorem for a function to belong to the class \sum(\mu;a) and generalize a Weierstrass-Enneper representation type theorem for the minimal surfaces given in [5] to spacelike minimal surfaces which lie in 3-dimensional Lorentz-Minkowski space L^3. We also obtain some estimates of the Gaussian curvature of the minimal surfaces in 3-dimensional Euclidean space R^3 and of the spacelike minimal surfaces in L^3.
Contact 3-Structure Qr-Warped Product Submanifold In Sasakian Space Form, Esmaiel Abedi, Ghorbanali Haghighatdoost, Mohammad Ilmakchi, Zahra Nazari
Contact 3-Structure Qr-Warped Product Submanifold In Sasakian Space Form, Esmaiel Abedi, Ghorbanali Haghighatdoost, Mohammad Ilmakchi, Zahra Nazari
Turkish Journal of Mathematics
In the present paper we obtain sharp estimates for the squared norm of the second fundamental form in terms of the mapping function for contact 3-structure CR-warped products isometrically immersed in Sasakian space form.
The Total Graph Of A Finite Commutative Ring, Ali Ramin
The Total Graph Of A Finite Commutative Ring, Ali Ramin
Turkish Journal of Mathematics
Let R be a commutative ring with Z(R), its set of zero-divisors and \mbox{Reg}(R), its set of regular elements. Total graph of R, denoted by T(\Gamma(R)), is the graph with all elements of R as vertices, and two distinct vertices x,y \in R, are adjacent in T(\Gamma(R)) if and only if x+y \in Z(R). In this paper, some properties of T(\Gamma(R)) have been investigated, where R is a finite commutative ring and a new upper bound for vertex-connectivity has been obtained in this case. Also, we have proved that the edge-connectivity of T(\Gamma(R)) coincides with the minimum degree if and …
A Note On Chaos In Product Maps, Risong Li, Xiaoliang Zhou
A Note On Chaos In Product Maps, Risong Li, Xiaoliang Zhou
Turkish Journal of Mathematics
In this paper, we mainly discuss how chaos conditions on semi-flows carry over to their products. We show that if two semi-flows (or even one of them) are sensitive, so does their product. On the other side, the product of two topologically transitive semi-flows need not be topologically transitive. We then provide several sufficient conditions under which the product of two chaotic semi-flows is chaotic in the sense of Devaney. Also, stronger forms of sensitivity and transitivity for product systems are studied. In particular, we introduce the notion of ergodic sensitivity and prove that for any given two (not-necessarily continuous) …
Asymmetric Synthesis Of \Alpha-(Heteroaryl)Alkylamines And \Alpha -Amino Acids Via Nucleophilic 1,2-Addition Of Lithiated Heterocycles To Aldehyde Samp-Hydrazones, Dieter Enders, Giuseppe Del Signore, Gerhard Raabe
Asymmetric Synthesis Of \Alpha-(Heteroaryl)Alkylamines And \Alpha -Amino Acids Via Nucleophilic 1,2-Addition Of Lithiated Heterocycles To Aldehyde Samp-Hydrazones, Dieter Enders, Giuseppe Del Signore, Gerhard Raabe
Turkish Journal of Chemistry
The asymmetric synthesis of \alpha-(heteroaryl)alkylamines was accomplished by employing a diastereoselective nucleophilic 1,2-addition of lithiated aromatic heterocycles to aldehyde SAMP-hydrazones, followed by BH_3 . THF or SmI_2 promoted removal of the chiral auxiliary. The CBz or benzoyl-protected amines were obtained in good yields (40\%--78\%) and excellent enantiomeric excesses (ee = 88\%--99\%). The methodology can be applied to the synthesis of highly enantioenriched \alpha-amino acids (ee = 90\%--99\%).