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Full-Text Articles in Physical Sciences and Mathematics

Corrigendum: On Density Theorems For Rings Of Krull Type With Zero Divisors, Başak Ay Saylam Jan 2017

Corrigendum: On Density Theorems For Rings Of Krull Type With Zero Divisors, Başak Ay Saylam

Turkish Journal of Mathematics

This corrigendum is written to correct some parts of the paper "On density theorems for rings of Krull type with zero divisors". The proofs of Proposition 2.4 and Proposition 4.3 are incorrect and the current note makes the appropriate corrections.


Arf Numerical Semigroups, Sedat İlhan, Hali̇l İbrahi̇m Karakaş Jan 2017

Arf Numerical Semigroups, Sedat İlhan, Hali̇l İbrahi̇m Karakaş

Turkish Journal of Mathematics

The aim of this work is to exhibit the relationship between the Arf closure of a numerical semigroup$S$ and its Lipman semigroup $L(S).$ This relationship is then used to give direct proofs of some characterizations of Arf numerical semigroups through their Lipman sequences of semigroups. We also give an algorithmic construction of the Arf closure of a numerical semigroup via its Lipman sequence of semigroups.


A Note On The Conjugacy Problem For Finite Sylow Subgroups Of Linear Pseudofinite Groups, Pinar Uğurlu Kowalski̇ Jan 2017

A Note On The Conjugacy Problem For Finite Sylow Subgroups Of Linear Pseudofinite Groups, Pinar Uğurlu Kowalski̇

Turkish Journal of Mathematics

We prove the conjugacy of Sylow $2$-subgroups in pseudofinite $\mathfrak{M}_c$ (in particular linear) groups under the assumption that there is at least one finite Sylow $2$-subgroup. We observe the importance of the pseudofiniteness assumption by analyzing an example of a linear group with nonconjugate finite Sylow $2$-subgroups, which was constructed by Platonov.


A Novel Kind Of Akns Integrable Couplings And Their Hamiltonian Structures, Yu-Juan Zhang, Wen-Xiu Ma, Ömer Ünsal Jan 2017

A Novel Kind Of Akns Integrable Couplings And Their Hamiltonian Structures, Yu-Juan Zhang, Wen-Xiu Ma, Ömer Ünsal

Turkish Journal of Mathematics

We present a novel hierarchy of AKNS integrable couplings based on a specific semidirect sum of Lie algebras associated with sl$(2)$. By applying the variational identity, we derive a bi-Hamiltonian structure of the resulting coupling systems, thereby showing their Liouville integrability.


More Accurate Jensen-Type Inequalities For Signed Measures Characterized Via Green Function And Applications, Mario Krnic, Josip Pecaric, Mirna Rodic Jan 2017

More Accurate Jensen-Type Inequalities For Signed Measures Characterized Via Green Function And Applications, Mario Krnic, Josip Pecaric, Mirna Rodic

Turkish Journal of Mathematics

In this paper we derive several improved forms of the Jensen inequality, giving the necessary and sufficient conditions for them to hold in the case of the real Stieltjes measure not necessarily positive.The obtained relations are characterized via the Green function. As an application, our main results are employed for constructing some classes of exponentially convex functions and some Cauchy-type means.


Some Notes On $Gqn$ Rings, Long Wang, Junchao Wei Jan 2017

Some Notes On $Gqn$ Rings, Long Wang, Junchao Wei

Turkish Journal of Mathematics

A ring $R$ is called ageneralized quasinormal ring (abbreviated as $GQN$ ring) if $ea∈N(R)$ for each $e∈ E(R)$ and $a∈ N(R)$. The class of $GQN$ rings is a proper generalization of quasinormal rings and $NI$ rings. Many properties of quasinormal rings are extended to $GQN$ rings. For a$GQN$ ring $R$ and $a∈ R$, it is shown that:1) if $a$ is a regular element, then $a$ is a strongly regular element;2) if $a$ is an exchange element, then $a$ is clean;3) if $R$ is a semiperiodic ring with $J(R)\neq N(R)$, then $R$ is commutative;4) if $R$ is an $MVNR$, then $R$ …


Unions And Ideals Of Locally Strongly Porous Sets, Maya Altinok, Oleksiy Dovgoshey, Mehmet Küçükaslan Jan 2017

Unions And Ideals Of Locally Strongly Porous Sets, Maya Altinok, Oleksiy Dovgoshey, Mehmet Küçükaslan

Turkish Journal of Mathematics

For subsets of $\mathbb R^+ = [0,∞)$ we introduce a notion of coherently porous sets as the sets for which the upper limit in the definition of porosity at a point is attained along the same sequence. We prove that the union of two strongly porous at $0$ sets is strongly porous if and only if these sets are coherently porous. This result leads to a characteristic property of the intersection of all maximal ideals contained in the family of strongly porous at $0$ subsets of $\mathbb R^+$. It is also shown that the union of a set $A \subseteq …


Universal Central Extensions Of $\Mathfrak{Sl}(M, N, A)$ Over Associative Superalgebras, Xabier García-Martínez, Manuel Ladra Jan 2017

Universal Central Extensions Of $\Mathfrak{Sl}(M, N, A)$ Over Associative Superalgebras, Xabier García-Martínez, Manuel Ladra

Turkish Journal of Mathematics

We find the universal central extension of the matrix superalgebras $\mathfrak{sl}(m, n, A)$, where $A$ is an associative superalgebra and $m+n = 3, 4$, and its relation with the Steinberg superalgebra $\mathfrak{st}(m, n,A)).$ We calculate $H_2$ $(\mathfrak{sl}(m, n,A))$ and $H_2$ $(\mathfrak{st}(m, n,A))$. Finally, we introduce a new method using the nonabelian tensor product of Lie superalgebras to and the connection between $H_2$ $(\mathfrak{sl}(m, n, A))$ and the cyclic homology of associative superalgebras for $m+n \geq 3$.


Modules Satisfying Double Chain Condition On Nonfinitely Generated Submodules Have Krull Dimension, Maryam Davoudian Jan 2017

Modules Satisfying Double Chain Condition On Nonfinitely Generated Submodules Have Krull Dimension, Maryam Davoudian

Turkish Journal of Mathematics

We prove the result in the title. We study submodules $N$ of a module $M$ such that whenever $\frac{M}{N}$ satisfies the double infinite chain condition so does $M$.Moreover, we observe that an $\alpha $-atomic module, where $\alpha\geq 2$ is an ordinal number, satisfies the previous chain if and only if it satisfies the descending chain condition on nonfinitely generated submodules.


On Focal Curves Of Null Cartan Curves, Hakan Şi̇mşek Jan 2017

On Focal Curves Of Null Cartan Curves, Hakan Şi̇mşek

Turkish Journal of Mathematics

The focal curve, which is determined as the locus of centers of osculatingpseudo-spheres of a null Cartan curve, is investigated in Minkowski(n+2)-space $\mathcal{M}^{n+2}.$ Moreover, a curve called \textit{accelerationfocal curve }of a null Cartan curve is introduced by using a new family of functions.


On Hölder Continuity Of Approximate Solution Maps To Vector Equilibrium Problems, Lam Quoc Anh, Kien Trung Nguyen, Tran Ngoc Tam Jan 2017

On Hölder Continuity Of Approximate Solution Maps To Vector Equilibrium Problems, Lam Quoc Anh, Kien Trung Nguyen, Tran Ngoc Tam

Turkish Journal of Mathematics

In this article, we considerparametric vector equilibrium problems in normed spaces. Sufficientconditions for Hölder continuity of approximate solution mappingswhere they are set-valued are established. As applications of theseresults, the Hölder continuity of the approximate solutionmappings for vector optimization problems and vector variationalinequalities are derived at the end of the paper. Our results arenew and include the existing ones in the literature.


Evaluation Of Euler-Like Sums Via Hurwitz Zeta Values, Ayhan Di̇l, Istvan Mezo, Mehmet Cenkci̇ Jan 2017

Evaluation Of Euler-Like Sums Via Hurwitz Zeta Values, Ayhan Di̇l, Istvan Mezo, Mehmet Cenkci̇

Turkish Journal of Mathematics

In this paper we collect two generalizations of harmonic numbers (namelygeneralized harmonic numbers and hyperharmonic numbers) under one roof.Recursion relations, closed-form evaluations, and generating functions of thisunified extension are obtained. In light of this notion we evaluate someparticular values of Euler sums in terms of odd zeta values. We alsoconsider the noninteger property and some arithmetical aspects of this unifiedextension.


On Armendariz-Like Properties In Amalgamated Algebras Along Ideals, Abdeslam Mimouni, Najib Mahdou, Mounir El Ourrachi Jan 2017

On Armendariz-Like Properties In Amalgamated Algebras Along Ideals, Abdeslam Mimouni, Najib Mahdou, Mounir El Ourrachi

Turkish Journal of Mathematics

Let $f: A\rightarrow B$ be a ring homomorphism and $J$ be an ideal of $B$. In this paper, we investigate the transfer of Armendariz-like properties to the amalgamation of $A$ with $B$ along $J$ with respect to $f$ (denoted by $A\bowtie^fJ)$ introduced and studied by D'Anna, Finocchiaro, and Fontana in 2009. Our aim is to provide necessary and sufficient conditions for $A\bowtie^fJ$ to be an Armendariz ring, nil-Armendariz ring, and weak Armendariz ring.


Optimality Conditions Via Weak Subdifferentials In Reflexive Banach Spaces, Sara Hassani, Musa Mammadov, Mina Jamshidi Jan 2017

Optimality Conditions Via Weak Subdifferentials In Reflexive Banach Spaces, Sara Hassani, Musa Mammadov, Mina Jamshidi

Turkish Journal of Mathematics

In this paper the relation between the weak subdifferentials and the directional derivatives, as well as optimality conditions for nonconvex optimization problems in reflexive Banach spaces, are investigated. It partly generalizes several related results obtained for finite dimensional spaces.


Some Fixed Point Theorems For Single Valued Strongly Contractive Mappings In Partially Ordered Ultrametric And Non-Archimedean Normed Spaces, Hamid Mamghaderi, Hashem Parvaneh Masiha, Meraj Hosseini Jan 2017

Some Fixed Point Theorems For Single Valued Strongly Contractive Mappings In Partially Ordered Ultrametric And Non-Archimedean Normed Spaces, Hamid Mamghaderi, Hashem Parvaneh Masiha, Meraj Hosseini

Turkish Journal of Mathematics

Let $ (X,d,\preceq) $ be a partially ordered ultrametric space and $ f:X\to X $ a single valued mapping. We obtain sufficient conditions for the existence of a fixed point for the strongly contractive mapping $ f $. We also investigate the existence of a fixed point for strongly contractive mappings defined on partially ordered non-Archimedean normed spaces under the same conditions. Finally, we give some examples to discuss the assumptions of the theorems.


Extensions Of Quasipolar Rings, Orhan Gürgün Jan 2017

Extensions Of Quasipolar Rings, Orhan Gürgün

Turkish Journal of Mathematics

An associative ring with identity is called quasipolar provided that for each $a\in R$ there exists an idempotent $p\in R$ such that $p\in comm^2(a)$, $a+p\in U(R)$ and $ap\in R^{qnil}$. In this article, we introduce the notion of quasipolar general rings (with or without identity). Some properties of quasipolar general rings are investigated. We prove that a general ring $I$ is quasipolar if and only if every element $a\in I$ can be written in the form $a=s+q$ where $s$ is strongly regular, $s\in comm^2(a)$, $q$ is quasinilpotent, and $sq=qs=0$. It is shown that every ideal of a quasipolar general ring is …


Maximal Subsemigroups And Finiteness Conditions On Transformation Semigroups With Fixed Sets, Yanisa Chaiya, Preeyanuch Honyam, Jintana Sanwong Jan 2017

Maximal Subsemigroups And Finiteness Conditions On Transformation Semigroups With Fixed Sets, Yanisa Chaiya, Preeyanuch Honyam, Jintana Sanwong

Turkish Journal of Mathematics

Let $Y$ be a fixed subset of a nonempty set $X$ and let $Fix(X,Y)$ be the set of all self maps on $X$ which fix all elements in $Y$. Then under the composition of maps, $Fix(X,Y)$ is a regular monoid. In this paper, we prove that there are only three types of maximal subsemigroups of $Fix\left(X,Y\right)$ and these maximal subsemigroups coincide with the maximal regular subsemigroups when $X\setminus Y$ is a finite set with $ X\setminus Y \geq 2$. We also give necessary and sufficient conditions for $Fix(X,Y)$ to be factorizable, unit-regular, and directly finite.


Dynamic Shum Inequalities, Ravi Agarwal, Martin Bohner, Donal O'Regan, Samir Saker Jan 2017

Dynamic Shum Inequalities, Ravi Agarwal, Martin Bohner, Donal O'Regan, Samir Saker

Turkish Journal of Mathematics

Recently, various forms and improvements of Opial dynamic inequalities have been given in the literature. In this paper, we give refinements of Opial inequalities on time scales that reduce in the continuous case to classical inequalities named after Beesack and Shum. These refinements are new in the important discrete case.


Sampling Theorem By Green's Function In A Space Ofvector-Functions, Hassan Atef Hassan Jan 2017

Sampling Theorem By Green's Function In A Space Ofvector-Functions, Hassan Atef Hassan

Turkish Journal of Mathematics

In this paper we give a sampling expansion for integral transforms whose kernels arise from Green's function of differential operators in a space of vector-functions. The differential operators are in a space of dimension $m$ and consist of systems of $m$ equations in $m$ unknowns. We assume the simplicity of the eigenvalues.


New Statistical Randomness Tests: 4-Bit Template Matching Tests, Fati̇h Sulak Jan 2017

New Statistical Randomness Tests: 4-Bit Template Matching Tests, Fati̇h Sulak

Turkish Journal of Mathematics

For cryptographic algorithms, secret keys should be generated randomly as the security of the system depends on the key and therefore generation of random sequences is vital. Randomness testing is done by means of statistical randomness tests. In this work, we show that the probabilities for the overlapping template matching test in the NIST test suite are only valid for a specific template and need to be recalculated for the other templates. We calculate the exact distribution for all 4-bit templates and propose new randomness tests, namely template matching tests. The new tests can be applied to any sequence of …


Near Optimal Step Size And Momentum In Gradient Descent For Quadratic Functions, Engi̇n Taş, Memmedağa Memmedli̇ Jan 2017

Near Optimal Step Size And Momentum In Gradient Descent For Quadratic Functions, Engi̇n Taş, Memmedağa Memmedli̇

Turkish Journal of Mathematics

Many problems in statistical estimation, classification, and regression can be cast as optimization problems. Gradient descent, which is one of the simplest and easy to implement multivariate optimization techniques, lies at the heart of many powerful classes of optimization methods. However, its major disadvantage is the slower rate of convergence with respect to the other more sophisticated algorithms. In order to improve the convergence speed of gradient descent, we simultaneously determine near-optimal scalar step size and momentum factor for gradient descent in a deterministic quadratic bowl from the largest and smallest eigenvalues of the Hessian. The resulting algorithm is demonstrated …


On A Family Of Saturated Numerical Semigroups With Multiplicity Four, Meral Süer, Sedat İlhan Jan 2017

On A Family Of Saturated Numerical Semigroups With Multiplicity Four, Meral Süer, Sedat İlhan

Turkish Journal of Mathematics

In this study, we will give some results on Arf numerical semigroups of multiplicity four generated by $\left\{ 4,k,k+1,k+2\right\} $ where $k$ is an integer not less than $5$ and $k\equiv 1(\mbox{mod } 4)$.


$\Mathcal{W}$-Gorenstein Objects In Triangulated Categories, Chaoling Huang, Kaituo Liu Jan 2017

$\Mathcal{W}$-Gorenstein Objects In Triangulated Categories, Chaoling Huang, Kaituo Liu

Turkish Journal of Mathematics

We fix a proper class of triangles $\xi$ in a triangulated category $\mathcal{C}$. Let $\mathcal{W}$ be a class of objects in $\mathcal{C}$ such that $\xi xt^i_\xi(W,\ W')=0$ for all $W, W'\in\mathcal{W}$ and all $i\geq 1$. In this paper, we introduce the notion of $\mathcal{W}$-Gorenstein objects and $\mathcal{G}(\mathcal{W})$-(co)resolution dimensions of any object in $\mathcal{C}$ and study the properties of $\mathcal{W}$-Gorenstein objects and characterize the finite $\mathcal{G}(\mathcal{W})$-(co)resolution dimensions of any object. Some applications are given.


Lie Symmetry Analysis And Exact Solutions Of The Sawada-Kotera Equation, Youwei Zhang Jan 2017

Lie Symmetry Analysis And Exact Solutions Of The Sawada-Kotera Equation, Youwei Zhang

Turkish Journal of Mathematics

In the present paper, the Sawada-Kotera equation is considered by Lie symmetry analysis. All of the geometric vector fields to the Sawada-Kotera equation are obtained, and then the symmetry reductions and exact solutions of the Sawada-Kotera equation are investigated. Our results show that symmetry analysis is a very efficient and powerful technique in finding the solution of the proposed equation.


A Mehrotra Predictor-Corrector Interior-Point Algorithm For Semidefinite Optimization, Mohammad Pirhaji, Maryam Zangiabadi, Hossein Mansouri Jan 2017

A Mehrotra Predictor-Corrector Interior-Point Algorithm For Semidefinite Optimization, Mohammad Pirhaji, Maryam Zangiabadi, Hossein Mansouri

Turkish Journal of Mathematics

This paper proposes a second-order Mehrotra-type predictor-corrector feasible interior-point algorithm for semidefinite optimization problems. In each iteration, the algorithm computes the Newton search directions through a new form of combination of the predictor and corrector directions. Using the Ai-Zhang wide neighborhood for linear complementarity problems, it is shown that the complexity bound of the algorithm is $O(\sqrt{n}\log \varepsilon^{-1})$ for the Nesterov-Todd search direction and $O({n}\log \varepsilon^{-1})$ for the Helmberg-Kojima-Monteiro search directions.


Dirac Systems With Regular And Singular Transmission Effects, Eki̇n Uğurlu Jan 2017

Dirac Systems With Regular And Singular Transmission Effects, Eki̇n Uğurlu

Turkish Journal of Mathematics

In this paper, we investigate the spectral properties of singular eigenparameter dependent dissipative problems in Weyl's limit-circle case with finite transmission conditions. In particular, these transmission conditions are assumed to be regular and singular. To analyze these problems we construct suitable Hilbert spaces with special inner products and linear operators associated with these problems. Using the equivalence of the Lax-Phillips scattering function and Sz-Nagy-Foiaş characteristic functions we prove that all root vectors of these dissipative operators are complete in Hilbert spaces.


On The Attached Prime Ideals Of Localcohomology Modules Defined By A Pair Of Ideals, Zohreh Habibi, Maryam Jahangiri, Khadijeh Ahmadi Amoli Jan 2017

On The Attached Prime Ideals Of Localcohomology Modules Defined By A Pair Of Ideals, Zohreh Habibi, Maryam Jahangiri, Khadijeh Ahmadi Amoli

Turkish Journal of Mathematics

Let $I$ and $J$ be two ideals of a commutative Noetherian ring $R$ and $M$ be an $R$-module of dimension $d$. For each $i\in N_0$ let $H^{i}_{I,J}(-)$ denote the $i$-th right derived functor of $\Gamma_{I,J}(-)$, where $\Gamma _{I,J}(M):=\{x \in M : I^{n}x\subseteq Jx \ \text {for} \ n\gg 1\}$. If $R$ is a complete local ring and $M$ is finite, then attached prime ideals of $H^{d-1}_{I,J}(M)$ are computed by means of the concept of co-localization. Moreover, we illustrate the attached prime ideals of $H^{t}_{I,J}(M)$ on a nonlocal ring $R$, for $t= \dim M$ and $t= (I,J,M)$, where $(I,J,M)$ is the …


Exponent Of Local Ring Extensions Of Galois Rings And Digraphs Of The $K$Th Power Mapping, Ittiwat Tocharoenirattisai, Yotsanan Meemark Jan 2017

Exponent Of Local Ring Extensions Of Galois Rings And Digraphs Of The $K$Th Power Mapping, Ittiwat Tocharoenirattisai, Yotsanan Meemark

Turkish Journal of Mathematics

In this paper, we consider a local extension $R$ of the Galois ring of the form $GR(p^{n},d)[x]/(f(x)^{a})$, where $n,d$, and $a$ are positive integers; $p$ is a prime; and $f(x)$ is a monic polynomial in $GR(p^{n},d)[x]$ of degree $r$ such that the reduction $\overline{f}(x)$ in $\mathbb{F}_{p^{d}}[x]$ is irreducible. We establish the exponent of $R$ without complete determination of its unit group structure. We obtain better analysis of the iteration graphs $G^{(k)}(R)$ induced from the $k$th power mapping including the conditions on symmetric digraphs. In addition, we work on the digraph over a finite chain ring $R$. The structure of $G^{(k)}_{2}(R)$ …


On The Volume Of The Indicatrix Of A Complex Finsler Space, Elena Popovici Jan 2017

On The Volume Of The Indicatrix Of A Complex Finsler Space, Elena Popovici

Turkish Journal of Mathematics

Following the study on volume of indicatrices in a real Finsler space, in this paper we are investigating some volume properties of the indicatrix considered in an arbitrary fixed point of a complex Finsler manifold. Since for each point of a complex Finsler space the indicatrix is an embedded CR-hypersurface of the punctured holomorphic tangent bundle, by means of its normal vector, the volume element of the indicatrix is determined. Thus, the volume function is pointed out and its variation is studied. Conditions under which the volume is constant are also determined and some classes of complex Finsler spaces with …


Characterization Of Substantially And Quasi-Substantially Efficient Solutions In Multiobjective Optimization Problems, Latif Pourkarimi, Masoud Karimi Jan 2017

Characterization Of Substantially And Quasi-Substantially Efficient Solutions In Multiobjective Optimization Problems, Latif Pourkarimi, Masoud Karimi

Turkish Journal of Mathematics

In this paper, we study the notion of substantial efficiency for a given multiobjective optimization problem. We provide two characterizations for substantially efficient solutions: the first one is based on a scalar problem and the second one is in terms of a stability concept. Moreover, this paper introduces the notion of quasi-substantial efficiency. Similar to those of substantial efficiency, two characterizations for quasi-substantially efficient solutions are obtained.