Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 412

Full-Text Articles in Physical Sciences and Mathematics

On A Tower Of Garcia And Stichtenoth, Seher Tutdere Jan 2014

On A Tower Of Garcia And Stichtenoth, Seher Tutdere

Turkish Journal of Mathematics

In 2003, Garcia and Stichtenoth constructed a recursive tower F = (F_n)_{n \geq 0} of algebraic function fields over the finite field F_q, where q = l^r with r \geq 1 and l > 2 is a power of the characteristic of F_q. They also gave a lower bound for the limit of this tower. In this paper, we compute the exact value of the genus of the algebraic function field F_n/F_q for each n \geq 0. Moreover, we prove that when q = 2^k, with k \geq 2, the limit of the tower F attains the lower bound given by …


Homological Dimensions Of Complexes Related To Cotorsion Pairs, Chongqing Wei, Limin Wang, Husheng Qiao Jan 2014

Homological Dimensions Of Complexes Related To Cotorsion Pairs, Chongqing Wei, Limin Wang, Husheng Qiao

Turkish Journal of Mathematics

Let (A, B) be a cotorsion pair in R-Mod. We define and study notions of A dimension and B dimension of unbounded complexes, which is given by means of dg-projective resolution and dg-injective resolution, respectively. As an application, we extend the Gorenstein flat dimension of complexes, which was defined by Iacob. Gorenstein cotorsion, FP-projective, FP-injective, Ding projective, and Ding injective dimension are also extended from modules to complexes. Moreover, we characterize Noetherian rings, von Neumann regular rings, and QF rings by the FP-projective, FP-injective, and Ding projective (injective) dimension of complexes, respectively.


Highly Nonconcurrent Longest Paths And Cycles In Lattices, Yasir Bashir Jan 2014

Highly Nonconcurrent Longest Paths And Cycles In Lattices, Yasir Bashir

Turkish Journal of Mathematics

We investigate here the connected graphs with the property that any pair of vertices are missed by some longest paths (or cycles), embeddable in n-dimensional lattices L^n where L denotes the set of integers.


On Transformations Of Index 1, Leyla Bugay, Osman Kelekci̇ Jan 2014

On Transformations Of Index 1, Leyla Bugay, Osman Kelekci̇

Turkish Journal of Mathematics

The index and the period of an element a of a finite semigroup are defined as the smallest values of m \geq 1 and r \geq 1 such that a^{m+r}=a^m, respectively. If m=1 then a is called an element of index 1. The aim of this paper is to find some properties of the elements of index 1 in T_n, which we call transformations of index 1.


Horizontally Submersions Of Contact Cr-Submanifolds, Fortune Massamba, Tshikunguila Tshikuna-Matamba Jan 2014

Horizontally Submersions Of Contact Cr-Submanifolds, Fortune Massamba, Tshikunguila Tshikuna-Matamba

Turkish Journal of Mathematics

In this paper, we discuss some geometric properties of almost contact metric submersions involving symplectic manifolds. We show that the structures of quasi-K-cosymplectic and quasi-Kenmotsu manifolds are related to (1, 2)-symplectic structures. For horizontally submersions of contact CR-submanifolds of quasi-K-cosymplectic and quasi-Kenmotsu manifolds, we study the principal characteristics and prove that their total spaces are CR-product. Curvature properties between curvatures of quasi-K-cosymplectic and quasi-Kenmotsu manifolds and the base spaces of such submersions are also established. We finally prove that, under a certain condition, the contact CR-submanifold of a quasi Kenmotsu manifold is locally a product of a totally geodesic leaf …


Moment Equalities For Sums Of Random Variables Via Integer Partitions And Faà Di Bruno's Formula, Dietmar Ferger Jan 2014

Moment Equalities For Sums Of Random Variables Via Integer Partitions And Faà Di Bruno's Formula, Dietmar Ferger

Turkish Journal of Mathematics

We give moment equalities for sums of independent and identically distributed random variables including, in particular, centered and specifically symmetric summands. Two different types of proofs, combinatorial and analytical, lead to 2 different types of formulas. Furthermore, the combinatorial method allows us to find the optimal lower and upper constants in the Marcinkiewicz--Zygmund inequalities in the case of even moment-orders. Our results are applied to give elementary proofs of the classical central limit theorem (CLT) and of the CLT for the empirical bootstrap. Moreover, we derive moment and exponential inequalities for self-normalized sums.


Central Configurations In The Collinear 5-Body Problem, Muhammad Shoaib, Anoop Sivasankaran, Abdulrehman Kashif Jan 2014

Central Configurations In The Collinear 5-Body Problem, Muhammad Shoaib, Anoop Sivasankaran, Abdulrehman Kashif

Turkish Journal of Mathematics

We study the inverse problem of central configuration of collinear general 4- and 5-body problems. A central configuration for n-body problems is formed if the position vector of each particle with respect to the center of mass is a common scalar multiple of its acceleration. In the 3-body problem, it is always possible to find 3 positive masses for any given 3 collinear positions given that they are central. This is not possible for more than 4-body problems in general. We consider a collinear 5-body problem and identify regions in the phase space where it is possible to choose positive …


Coloring Hypercomplete And Hyperpath Graphs, Yusuf Ci̇van, Demet Taylan Jan 2014

Coloring Hypercomplete And Hyperpath Graphs, Yusuf Ci̇van, Demet Taylan

Turkish Journal of Mathematics

Given a graph G with an induced subgraph H and a family F of graphs, we introduce a (hyper)graph H_H(G;F)=(V_H, E_H), the hyper-H (hyper)graph of G with respect to F, whose vertices are induced copies of H in G, and \{H_1,H_2,\ldots,H_r\} \in E_H if and only if the induced subgraph of G by the set \cup_{i=1}^r H_i is isomorphic to a graph F in the family F, and the integer r is the least integer for F with this property. When H is a k-complete or a k-path of G, we abbreviate H_{K_k}(G;F) and H_{P_k}(G;F) to H_k(G;F) and HP_k(G;F), respectively. …


Euler-Seidel Matrices Over F_P, Nesri̇n Tutaş Jan 2014

Euler-Seidel Matrices Over F_P, Nesri̇n Tutaş

Turkish Journal of Mathematics

A Euler--Seidel matrix is determined by an infinite sequence whose elements are given by recursion. The recurrence relations are investigated for numbers and polynomials such as hyperharmonics, Lucas numbers, and Euler and Genocchi polynomials. Linear recurring sequences in finite fields are employed, for instance, in coding theory and in several branches of electrical engineering. In this work, we define the period of a Euler--Seidel matrix over a field F_p with p elements, where p is a prime number. We give some results for the matrix whose initial sequence is \{s_r(n)\}_{n=0}^{\infty}, where s_r(n)=\sum_{k=0}^n {\binom{n}{k}}^r, n \geq 0, and r is a …


On Betti Series Of The Universal Modules Of Second Order Derivations Of \Frac{K[X_1,X_2,...,X_S]}{(F)}, Ali̇ Erdoğan, Hali̇se Meli̇s Teki̇n Akçi̇n Jan 2014

On Betti Series Of The Universal Modules Of Second Order Derivations Of \Frac{K[X_1,X_2,...,X_S]}{(F)}, Ali̇ Erdoğan, Hali̇se Meli̇s Teki̇n Akçi̇n

Turkish Journal of Mathematics

Let R be a coordinate ring of an affine irreducible curve represented by \frac{k[x_1,x_2,...,x_s]}{(f)} and m be a maximal ideal of R. In this article, the Betti series of \Omega_2(R_m) is studied. We proved that the Betti series of \Omega_2(R_m), where \Omega_2(R_m) denotes the universal module of second order derivations of R_m, is a rational function under some conditions.


Some Results On T-Noncosingular Modules, Rachid Tribak Jan 2014

Some Results On T-Noncosingular Modules, Rachid Tribak

Turkish Journal of Mathematics

The notion of T-noncosingularity of a module has been introduced and studied recently. In this article, a number of new results of this property are provided. It is shown that over a commutative semilocal ring R such that Jac(R) is a nil ideal, every T-noncosingular module is semisimple. We prove that for a perfect ring R, the class of T-noncosingular modules is closed under direct sums if and only if R is a primary decomposable ring. Finitely generated T-noncosingular modules over commutative rings are shown to be precisely those having zero Jacobson radical. We also show that for a simple …


A Class Of Uniquely (Strongly) Clean Rings, Orhan Gürgün, Ayşe Çi̇ğdem Özcan Jan 2014

A Class Of Uniquely (Strongly) Clean Rings, Orhan Gürgün, Ayşe Çi̇ğdem Özcan

Turkish Journal of Mathematics

In this paper we call a ring R \delta_r-clean if every element is the sum of an idempotent and an element in \delta(R_R) where \delta(R_R) is the intersection of all essential maximal right ideals of R. If this representation is unique (and the elements commute) for every element we call the ring uniquely (strongly) \delta_r-clean. Various basic characterizations and properties of these rings are proved, and many extensions are investigated and many examples are given. In particular, we see that the class of \delta_r-clean rings lies between the class of uniquely clean rings and the class of exchange rings, and …


On The Structure Of Some Modules Over Generalized Soluble Groups, Leonid Andreevich Kurdachenko, Igor Yakov Subbotin, Vasiliy Anatolievich Chupordya Jan 2014

On The Structure Of Some Modules Over Generalized Soluble Groups, Leonid Andreevich Kurdachenko, Igor Yakov Subbotin, Vasiliy Anatolievich Chupordya

Turkish Journal of Mathematics

Let R be a ring and G a group. An R-module A is said to be Artinian-by-(finite rank) if Tor_R(A) is Artinian and A/ Tor_R(A) has finite R-rank. We study a module A over a group ring RG such that A/C_A(H) is Artinian-by-(finite rank) (as an R-module) for every proper subgroup H.


On 2 Nonsplit Extension Groups Associated With Hs And Hs:2, Jamshid Moori, Thekiso Seretlo Jan 2014

On 2 Nonsplit Extension Groups Associated With Hs And Hs:2, Jamshid Moori, Thekiso Seretlo

Turkish Journal of Mathematics

The group HS:2 is the full automorphism group of the Higman--Sims group HS. The groups 2^{4.}S_6 and 2^{5.}S_6 are maximal subgroups of HS and HS:2, respectively. The group 2^{4.}S_6 is of order 11520 and 2^{5.}S_6 is of order 23040 and each of them is of index 3 850 in HS and HS:2, respectively. The aim of this paper is to first construct \overline{G} = 2^{5.}S_6 as a group of the form 2^{4.}S_6.2 (that is, \overline{G} = G_1.2) and then compute the character tables of these 2 nonsplit extension groups by using the method of Fischer--Clifford theory. We will show that …


On Finsler Metrics With Vanishing S-Curvature, Akbar Tayebi, Hassan Sadeghi, Esmaeil Peyghan Jan 2014

On Finsler Metrics With Vanishing S-Curvature, Akbar Tayebi, Hassan Sadeghi, Esmaeil Peyghan

Turkish Journal of Mathematics

In this paper, we consider Finsler metrics defined by a Riemannian metric and a 1-form on a manifold. We study these metrics with vanishing S-curvature. We find some conditions under which such a Finsler metric is Berwaldian or locally Minkowskian.


Conformally Parallel Spin(7) Structures On Solvmanifolds, Selman Uğuz Jan 2014

Conformally Parallel Spin(7) Structures On Solvmanifolds, Selman Uğuz

Turkish Journal of Mathematics

In this paper we review the Spin(7) geometry in relation to solvmanifolds. Starting from a 7-dimensional nilpotent Lie group N endowed with an invariant G_2 structure, we present an example of a homogeneous conformally parallel Spin(7) metric on an associated solvmanifold. It is thought that this paper could lead to very interesting and exciting areas of research and new results in the direction of (locally conformally) parallel Spin(7) structures.


Geometry Of Almost Cliffordian Manifolds: Classes Of Subordinated Connections, Jaroslav Hrdina, Petr Vasik Jan 2014

Geometry Of Almost Cliffordian Manifolds: Classes Of Subordinated Connections, Jaroslav Hrdina, Petr Vasik

Turkish Journal of Mathematics

An almost Clifford and an almost Cliffordian manifold is a G--structure based on the definition of Clifford algebras. An almost Clifford manifold based on O:= Cl (s,t) is given by a reduction of the structure group GL(km, R) to GL(m, O), where k=2^{s+t} and m \in N. An almost Cliffordian manifold is given by a reduction of the structure group to GL(m, O) GL(1, O). We prove that an almost Clifford manifold based on O is such that there exists a unique subordinated connection, while the case of an almost Cliffordian manifold based on O is more rich. A class …


Early Pleistocene Freshwater Communities And Rodents From The Pasinler Basin (Erzurum Province, North-Eastern Turkey), Davit Vasilyan, Simon Schneider, Memet Sali̇h Bayraktutan, Şevket Şen Jan 2014

Early Pleistocene Freshwater Communities And Rodents From The Pasinler Basin (Erzurum Province, North-Eastern Turkey), Davit Vasilyan, Simon Schneider, Memet Sali̇h Bayraktutan, Şevket Şen

Turkish Journal of Earth Sciences

An Early Pleistocene lacustrine faunal assemblage from Pasinler (Erzurum Province, north-eastern Turkey) is described, which encompasses 13 mollusc, 5 fish, 2 amphibian, 1 reptile, and 1 mammal species. The autochthonous freshwater mollusc fauna indicates shallow stagnant waters and a fine-sandy to muddy lake bottom, grown with submersed plants. The fish community (Leuciscus sp., Rutilus sp., Chondrostoma sp., Leuciscinae sp. 1 and 2, and Capoeta sp.) and autochthonous herpetofauna (Latonia sp. and Natrix sp.) provide evidence of a well-oxygenised palaeolake with rich periphyton and partially rocky to gravelly bottom. Moreover, the presence of the terrestrial snail Caspicyclotus cf. akramowsii, the peri- …


Ree Geochemical Characteristics Of Titanium-Rich Bauxites: The Permian Kanigorgeh Horizon, Nw Iran, Ali Abedini, Ali Asghar Calagari Jan 2014

Ree Geochemical Characteristics Of Titanium-Rich Bauxites: The Permian Kanigorgeh Horizon, Nw Iran, Ali Abedini, Ali Asghar Calagari

Turkish Journal of Earth Sciences

The Permian Kanigorgeh bauxite horizon is one of the typical titanium-rich bauxite deposits in the northeast of Bukan, West Azerbaijan Province, NW Iran. It is a part of the Irano-Himalayan karst bauxite belt and was developed as discontinuous stratified layers and lenses in Upper Permian carbonates. Mineralogically, diaspore and kaolinite are 2 major mineral phases accompanied by boehmite, smectite, illite, rutile, anatase, hematite, goethite, chlorite, quartz, and plagioclase as minor phases. Geochemical considerations for a selected profile indicate that the concentration values of rare earth elements (REEs) in the bauxite ores range from 8.9 to 200.4 ppm. Eu and Ce …


Structural Analyses Of Şaphane Relay Ramps And Fault Linkage Evolution In Active Extensional Regime, Western Turkey, Şule Gürboğa Jan 2014

Structural Analyses Of Şaphane Relay Ramps And Fault Linkage Evolution In Active Extensional Regime, Western Turkey, Şule Gürboğa

Turkish Journal of Earth Sciences

The Şaphane relay ramps (SAR-I and SAR-II) are well-developed structures formed by extensional tectonic settings in western Turkey. Their formation is controlled by the configuration of 2 different breaching faults located in between and the overlapping area of 3 normal faults, which are the Şaphane, Gürlek, and Yumrutaş faults. The relay ramps form within a ~3 km-wide and ~12 km-long interaction zone between 045° and 060° trending faults on the northern boundary of the Erdoğmuş-Yenigediz graben. Some variations in structural styles and its products (for example, overlapping slip-lines (slickenlines), fractures, and antithetic-synthetic faults) are observed along the breaching faults in …


Coherence Analysis On Thermal Effect For Power Cables Under Different Environmental Conditions, Sezai̇ Taşkin, Şahi̇n Serhat Şeker, Özcan Kalenderli̇, Murat Karahan Jan 2014

Coherence Analysis On Thermal Effect For Power Cables Under Different Environmental Conditions, Sezai̇ Taşkin, Şahi̇n Serhat Şeker, Özcan Kalenderli̇, Murat Karahan

Turkish Journal of Electrical Engineering and Computer Sciences

There are 2 important aspects of this research; these are the experimental study and the data analysis, which are based on coherence analysis. In this study, a low-voltage power cable is tested under 2 different environments, air and water, and the variations in temperature are measured for the conductor, the sheath parts of the cable, and the environment. The recorded test data are analyzed using such as coherence analysis. This in turn provides the means to determine the relationship among the sheath, conductor, and the environment. In conclusion, high correlated peaks in the frequency domain are used to determine the …


Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel Jan 2014

Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel

Turkish Journal of Electrical Engineering and Computer Sciences

A nested bitemporal relational data model and its query language are implemented. The bitemporal atom (BTA) is the fundamental construct to represent temporal data and it contains 5 components: a value, the lower and upper bounds of valid time, and the lower and upper bounds of the recoding time. We consider 2 types of data structures for storing BTAs: 1) string representation and 2) abstract data-type representation. We also develop a preprocessor for translating a bitemporal structured query language (BtSQL) statement into standard SQL statements. The BtSQL includes the select, insert, delete, and update statements of the SQL, extended for …


Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky Jan 2014

Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we deal with the improvement of the positioning accuracy of distance vector (DV)-based positioning algorithms, which use angular information DV- angle of arrival (AoA). This algorithm belongs to an ad-hoc positioning system. We focus on the improvement of the algorithm and its enhanced version is presented. The angular information of particular nodes is obtained and processed by the original algorithm; however, the final position estimation is determined by the proposed novel algorithm using only a subset of all intersections. We assign weights to the individual intersections according to their positions and the positions of the RNs. For …


A Reduced Probabilistic Neural Network For The Classification Of Large Databases, Abdelhadi Lotfi, Abdelkader Benyettou Jan 2014

A Reduced Probabilistic Neural Network For The Classification Of Large Databases, Abdelhadi Lotfi, Abdelkader Benyettou

Turkish Journal of Electrical Engineering and Computer Sciences

The probabilistic neural network (PNN) is a special type of radial basis neural network used mainly for classification problems. Due to the size of the network after training, this type of network is usually used for problems with a small-sized training dataset. In this paper, a new training algorithm is presented for use with large training databases. Application to the handwritten digit database shows that the reduced PNN performs better than the standard PNN for all of the studied cases with a big gain in size and processing speed. This new type of neural network can be used easily for …


Expert Doctor Verdis: Integrated Medical Expert System, Aytürk Keleş Jan 2014

Expert Doctor Verdis: Integrated Medical Expert System, Aytürk Keleş

Turkish Journal of Electrical Engineering and Computer Sciences

Innovative medical technologies are developing day by day, as there is an important need for integrated medical expert systems (ESs) that will help to effectively manage and control diagnosis and treatment processes. These systems, with new approaches, have improved the experiences and capabilities of physicians to make the diagnosis of diseases. In this work, an integrated medical ES called Expert Doctor Verdis (Ex-Dr Verdis) is developed, which combines an advanced medical information system containing various medical services supported by information technologies, with ES capabilities in a single system. This system is also one kind of decision support system. Implementation of …


Design And Realization Of A Welding Oscillator, Muci̇z Özcan Jan 2014

Design And Realization Of A Welding Oscillator, Muci̇z Özcan

Turkish Journal of Electrical Engineering and Computer Sciences

Welding is one of the most popular methods to combine metal pieces in manufacturing processes. Arc welding, among all welding techniques, is the most commonly used in manufacturing due to its cost and flexibility. During the manufacturing process, arc welding is either performed by an operator or by automatic tools such as welding oscillators. Using automatic tools has advantages over manual use, as the process will be faster, cheaper, and have less welding flaws. In this paper, a homemade welding oscillator and the method to manufacture it are presented. The presented welding oscillator can be manufactured for a very low …


The Results Of The First Photonuclear Reaction Performed In Turkey: The Zinc Example, İsmai̇l Boztosun, Haris Dapo, Süleyman Fati̇h Özmen, Yi̇ği̇t Çeçen, Mesut Karakoç, Abdullah Çoban, Alp Cesur, Tanfer Caner, Edi̇p Bayram, Gi̇zem Büşra Keller, Beyza Küçük, Abdullah Güvendi̇, Melek Derman, Deni̇z Kaya Jan 2014

The Results Of The First Photonuclear Reaction Performed In Turkey: The Zinc Example, İsmai̇l Boztosun, Haris Dapo, Süleyman Fati̇h Özmen, Yi̇ği̇t Çeçen, Mesut Karakoç, Abdullah Çoban, Alp Cesur, Tanfer Caner, Edi̇p Bayram, Gi̇zem Büşra Keller, Beyza Küçük, Abdullah Güvendi̇, Melek Derman, Deni̇z Kaya

Turkish Journal of Physics

We have investigated the decays of several zinc isotopes produced by photonuclear reactions, which were induced by bremsstrahlung photon beams from a clinical e-linac. A photon beam of 18 MeV endpoint energy was directed at a target consisting of primarily zinc isotopes in their natural abundances. Subsequently, the induced decays of unstable zinc isotopes were measured with an HPGe detector twice, once shortly after irradiation and once on the following day. Decays of Zn-63, Zn-65, Zn-69m, and Cu-67 were measured and fitted. In addition, the gamma energy levels of the daughters of these decays were measured with good accuracy. All …


Theoretical Investigations Of Pt_3x (X = Al, Sc, Hf, Zr) Ground State, Adewumi Isaac Popoola, Lesley Heath Chown, Lesley Alison Cornish Jan 2014

Theoretical Investigations Of Pt_3x (X = Al, Sc, Hf, Zr) Ground State, Adewumi Isaac Popoola, Lesley Heath Chown, Lesley Alison Cornish

Turkish Journal of Physics

The electronic structure of Pt_3X compounds showed that Pt_3Hf and Pt_3Zr were more stable for the D0_{24} structure, rather than L1_2. The compound Pt_3Al was predicted to be the hardest and most ductile, but not with the L1_2 structure at ground state. The density of states showed that Pt_3Hf, Pt_3Zr, and Pt_3Al can be stabilized to the L1_2 phase with suitable element addition. All calculations were done within the density functional theory framework.


Evidence That Photons Have Extension In Space, Randy Wayne Jan 2014

Evidence That Photons Have Extension In Space, Randy Wayne

Turkish Journal of Physics

Satyendra Nath Bose realized that there was a logical inconsistency in the derivation of Planck's radiation law since the derivation used to obtain the temperature-independent prefactor in the blackbody radiation law had been based in part on classical wave hypotheses, such as the number of degrees of freedom of the ether. Bose worked out a strictly quantum derivation by combining the quantum hypothesis with statistical mechanics to determine the number of states of each mode that would occupy a 6-dimensional phase space. Here I use the model of an extended photon to show that the temperature-independent prefactor of Planck's radiation …


Deriving The Snel-Descartes Law For A Single Photon, Randy Wayne Jan 2014

Deriving The Snel-Descartes Law For A Single Photon, Randy Wayne

Turkish Journal of Physics

The laws of reflection and refraction are typically derived using a dispersion relation that assumes that the angular frequency stays the same across a vacuum--dielectric interface and that the angular wave number increases. At the single photon level, this means that the total energy of the photon is conserved but the linear momentum is not. Here I derive the laws of reflection and refraction for a single photon using a dispersion relation that is consistent with the conservation of both total energy and linear momentum. To ensure that both conservation laws are upheld, the optical path length must be considered …