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Articles 8161 - 8190 of 10319
Full-Text Articles in Physical Sciences and Mathematics
A Vrp-Based Route Planning For A Mobile Robot Group, Osman Parlaktuna, Aydin Si̇pahi̇oğlu, Ahmet Yazici
A Vrp-Based Route Planning For A Mobile Robot Group, Osman Parlaktuna, Aydin Si̇pahi̇oğlu, Ahmet Yazici
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, a vehicle routing problem-based approach is presented to construct non-intersecting routes for the members of a mobile robot team. It is assumed that each robot starts from a central location such as the charging point, completes its route and returns to the starting location. The proposed method consists of three algorithms: a sweep algorithm determines the position of each node in clockwise (or counter clockwise) manner with respect to the starting location; savings algorithm calculates the saving obtained by adding a node to the route of a robot; Dijkstra's shortest path algorithm is used to calculate the …
Aggregation In Swarm Robotic Systems: Evolution And Probabilistic Control, Onur Soysal, Erki̇n Bahçeci̇, Erol Şahi̇n
Aggregation In Swarm Robotic Systems: Evolution And Probabilistic Control, Onur Soysal, Erki̇n Bahçeci̇, Erol Şahi̇n
Turkish Journal of Electrical Engineering and Computer Sciences
In this study we investigate two approachees for aggregation behavior in swarm robotics systems: Evolutionary methods and probabilistic control. In first part, aggregation behavior is chosen as a case, where performance and scalability of aggregation behaviors of perceptron controllers that are evolved for a simulated swarm robotic system are systematically studied with different parameter settings. Using a cluster of computers to run simulations in parallel, four experiments are conducted varying some of the parameters. Rules of thumb are derived, which can be of guidance to the use of evolutionary methods to generate other swarm robotic behaviors as well. In the …
A Communication Module And Tdma Scheduling For A Swarm Of Small Submarines, Ram Somaraju, Felix Schill
A Communication Module And Tdma Scheduling For A Swarm Of Small Submarines, Ram Somaraju, Felix Schill
Turkish Journal of Electrical Engineering and Computer Sciences
Swarming algorithms usually require fast and reliable local information distribution among neighbouring nodes. Additionally, many applications also require global information distribution in the shortest possible time. We show that communication links with a range which is small compared to the size of the swarm offer many advantages. We propose a system using low frequency radio communication as a viable alternative to acoustic communication. A time division multiple access algorithm is presented together with results from simulations. The presented system can be effectively used in large scale swarms of small submersibles.
Design And Implementation Of An Ad-Hoc Routing Protocol For Mobile Robots, Carlos Agüero, Jose M. Canas, Miguel OrtuNo, Vicente Matellan
Design And Implementation Of An Ad-Hoc Routing Protocol For Mobile Robots, Carlos Agüero, Jose M. Canas, Miguel OrtuNo, Vicente Matellan
Turkish Journal of Electrical Engineering and Computer Sciences
Mobile robots need to be able to communicate among themselves, as well as with hosts participating in the task that they are all involved in. Wired networks are obviously not suitable for mobile robots. Current wireless networks based on a fixed infrastructure (GSM, WiFi, etc.) to route packets may not be suitable because this infrastructure does not cover every place and the requirements of its resources. The best choice for mobile robots are Ad-Hoc networks, which are wireless and do not need a fixed infrastructure. This article describes PERA, a complete communications library including link, net, and transport layers for …
A Treatment Of A Higher-Order Singular Lagrangian As Fields System, N. I. Farahat, M. R. Heles
A Treatment Of A Higher-Order Singular Lagrangian As Fields System, N. I. Farahat, M. R. Heles
Turkish Journal of Physics
The higher-order singular Lagrangian system is treated as field system. Euler-Lagrange equations are solved with some constraints. An example is studied and a comparison with Hamiltonian formulation is done.
Tunneling-Enhanced Recombination In Polycrystalline Cds/Cdte Solar Cells, Habi̇be Bayhan
Tunneling-Enhanced Recombination In Polycrystalline Cds/Cdte Solar Cells, Habi̇be Bayhan
Turkish Journal of Physics
The dominant dark current transport mechanism in as-grown and CdCl_2 processed CdS/CdTe heterojunction solar cells for temperatures below 300~K was investigated. The current-voltage properties of these solar cells is explained via tunnelling enhanced bulk and interface recombination models which give a quantitative description of the electronic loss mechanisms in the chalcopyrite-based heterojunction solar cells. The temperature dependence of the saturation current and the diode ideality factors of the as-grown and CdCl_2 processed CdTe solar cells are shown to be well described by this model.
Cherenkov Radiation In Homogeneous Isotropic Chiral Media, Pierre Hillion
Cherenkov Radiation In Homogeneous Isotropic Chiral Media, Pierre Hillion
Turkish Journal of Physics
We present a Fourier transform analysis of Cherenkov radiation for a point charge uniformly moving inside a 2D-homogeneous, isotropic, unbounded, chiral medium endowed with the Drude-Born-Fedorov constitutive relations when the chirality parameter ß and the wave number k make negligible the ß^2k^2 terms. The electromagnetic field is not described in terms of circularly right and left polarized waves but in terms of TM and TE components. The Cherenkov radiation arises when the velocity v of the point charge is greater than the phase velocity c/n, where n is the refractive index of the chiral medium and the electromagnetic field stands …
Assessment Of Wind Power Potential For Coastal Areas Of Pakistan, M. Akhlaque Ahmed, Firoz Ahmed, M. Wasim Akhtar
Assessment Of Wind Power Potential For Coastal Areas Of Pakistan, M. Akhlaque Ahmed, Firoz Ahmed, M. Wasim Akhtar
Turkish Journal of Physics
Selected coastal areas of Pakistan (Karachi, Ormara, Jivani and Pasni) were studied for the possibility of wind energy generation, using available meteorological data. Wind speed pattern, Extractable Wind power, Wind Energy and associated Weibull parameter for these coastal areas have been examined. The analysis also includes seasonal changes in wind speed values. The power output using fast and slow wind machines using different blade diameters have been estimated to explore the possible use for irrigation deep well pumping and small scale power generation. Along with this, 4 KW and 20 KW aero generators were also examined. It was found that, …
Effect Of Thermal Annealing On The Band Gap And Optical Properties Of Chemical Bath Deposited Znse Thin Films, F. I. Ezema, A. B. C. Ekwealor, R. U. Osuji
Effect Of Thermal Annealing On The Band Gap And Optical Properties Of Chemical Bath Deposited Znse Thin Films, F. I. Ezema, A. B. C. Ekwealor, R. U. Osuji
Turkish Journal of Physics
Zinc selenide (ZnSe) thin films were deposited on glass substrate using the chemical bath deposition method at room temperature from aqueous solutions of zinc sulphate and sodium selenosulfate in which sodium hydroxide was employed as complexing agents. The `as-deposited' ZnSe thin films are red in color and annealed in oven at 473 K for 1 hour and on a hot plate in open air at 333 K for 5 minutes, affecting the morphological and optical properties. Optical properties such as absorption coefficient \alpha and extinction coefficient k, were determined using the absorbance and transmission measurement from Unico UV-2102 PC spectrophotometer, …
Phase Distribution Of The Output Of Jaynes-Cummings Model With The Superposition Of Squeezed Displaced Fock States, Gamal Mohamed Abd Al-Kader
Phase Distribution Of The Output Of Jaynes-Cummings Model With The Superposition Of Squeezed Displaced Fock States, Gamal Mohamed Abd Al-Kader
Turkish Journal of Physics
The Wigner quasi-probability function for the superposition of squeezed displaced Fock states (SDFS's) is reviewed. The interaction of these states with a two-level atom in cavity with the presence of additional Kerr medium is studied. Exact general matrix elements of the time-dependent operators of a Jaynes-Cummings model (JCM), in the presence of a Kerr medium, with these states are derived. We have obtained the phase distribution by two different ways: one is by Pegg-Barnett formalism, the second is by integration of the Wigner function over the radial variable. Results of these two approaches are compared. The Wigner phase distributions for …
Modulated Photoconductivity Studies Of A-As_2se_3 Thin Films, Ruhi̇ Kaplan
Modulated Photoconductivity Studies Of A-As_2se_3 Thin Films, Ruhi̇ Kaplan
Turkish Journal of Physics
Modulated photocurrent measurements in amorphous arsenic triselenide (a-As_2Se_3) is reported. Particular focus is paid towards photocarrier lifetimes as a function of temperature, and applied electric field (i.e. dc) were determined by using the quadrature frequency-resolved spectroscopy method. The activation energy from the photocurrent as a function of temperature was determined to be about 125 meV for a constant illumination intensity of 2.3 mW. Its value was found to be almost independent of the applied electric field. The exponent \nu in the power law relationship (I_{ph} \propto G^v) between generating flux and photocurrent was obtained under different electric fields. The electric …
Electrical Switching Behaviour In Lead Phosphovanadate Glasses, B. Sujatha, C. Narayana Reddy
Electrical Switching Behaviour In Lead Phosphovanadate Glasses, B. Sujatha, C. Narayana Reddy
Turkish Journal of Physics
Electrical switching behaviour of lead phosphovanadate glasses were studied by determining the current-voltage characteristics. All the investigated glasses exhibit the dependence of threshold voltages on temperature, thickness and composition. Below holding current the I - V characteristics obey Ohms law followed by a negative resistance region where the bulk behaviour dominates and at higher values of current the samples goes to a low resistance state. The studied glasses exhibit memory type switching. It is suggested that the initial switching and channel formation are due to electronic, while thermal effects dominate in the formation of channels.
Plane Symmetric Solutions Of Gravitational Field Equations In Five Dimensions, A. N. Aliev, Hakan Cebeci̇, Teki̇n Dereli̇
Plane Symmetric Solutions Of Gravitational Field Equations In Five Dimensions, A. N. Aliev, Hakan Cebeci̇, Teki̇n Dereli̇
Turkish Journal of Physics
We present the effective field equations obtained from a generalized gravity action with Euler-Poincaré term and a cosmological constant in a D dimensional bulk space-time. A class of plane-symmetric solutions that describe a 3-brane world embedded in a D=5 dimensional bulk space-time are given.
Degenerate Spin Structures And The Lévy-Leblond Equation, Teki̇n Dereli̇, Şahi̇n Koçak, Murat Li̇moncu
Degenerate Spin Structures And The Lévy-Leblond Equation, Teki̇n Dereli̇, Şahi̇n Koçak, Murat Li̇moncu
Turkish Journal of Physics
Newton-Cartan manifolds and the Galilei group are defined by the use of co-rank one degenerate metric tensor. Newton-Cartan connection is lifted to the degenerate spinor bundle over a Newton-Cartan 4-manifold by the aid of degenerate spin group. Levy-Leblond equation is constructed with the lifted connection.
Origin And Tectonic Significance Of The Metamorphic Sole And Isolated Dykes Of The Divriği Ophiolite (Sivas, Turkey): Evidence For Slab Break-Off Prior To Ophiolite Emplacement, Osman Parlak, Hüseyi̇n Yilmaz, Durmuş Boztuğ
Origin And Tectonic Significance Of The Metamorphic Sole And Isolated Dykes Of The Divriği Ophiolite (Sivas, Turkey): Evidence For Slab Break-Off Prior To Ophiolite Emplacement, Osman Parlak, Hüseyi̇n Yilmaz, Durmuş Boztuğ
Turkish Journal of Earth Sciences
The Late Cretaceous Divriği ophiolite of east-central Anatolia comprises, from bottom to top, an ophiolitic mélange, metamorphic sole and remnants of oceanic lithosphere. The ophiolitic mélange has been thrust onto the Lower Carboniferous-Campanian Munzur Limestone (Tauride platform), and is in turn tectonically overlain by the metamorphic sole. The metamorphic-sole rocks are represented by amphibolite, plagioclase amphibolite, plagioclase-amphibole schist, plagioclase-epidote-amphibole schist and calc-schist. The oceanic-lithosphere remnant exhibits a complete section, excluding volcanic rocks, comprising mantle tectonites, ultramafic to mafic cumulates, isotropic gabbros and sheeted dykes. Isolated dykes intrude the metamorphic sole and mantle tectonites at different structural levels. The metamorphic-sole rocks …
Inequality For Ricci Curvature Of Slant Submanifolds In Cosymplectic Space Forms, Dae Won Yoon
Inequality For Ricci Curvature Of Slant Submanifolds In Cosymplectic Space Forms, Dae Won Yoon
Turkish Journal of Mathematics
In this article, we establish inequalities between the Ricci curvature and the squared mean curvature, and also between the k-Ricci curvature and the scalar curvature for a slant, semi-slant and bi-slant submanifold in a cosymplectic space form of constant \varphi-sectional curvature with arbitrary codimension.
Remarks About Some Weierstrass Type Results, Mihai Turinici
Remarks About Some Weierstrass Type Results, Mihai Turinici
Turkish Journal of Mathematics
The Weierstrass type results of Gajek and Zagrodny [7] are not in general retainable in the precise context. Our first aim in this exposition is to show that a completion of the imposed conditions may be offered so that these results be true. As a second aim, alternate proofs of the statements in question are performed, via ordering principles comparable with the one in Brezis and Browder [3].
Mohr-Circle-Based Rotational Invariants Of A Magnetotelluric Data Set From The Thrace Region Of Turkey: Geological Implications, Murat Bayrak, Aysan Gürer, Ö. Feyzi̇ Gürer, O. Meti̇n İlkişik, Ahmet T. Başokur
Mohr-Circle-Based Rotational Invariants Of A Magnetotelluric Data Set From The Thrace Region Of Turkey: Geological Implications, Murat Bayrak, Aysan Gürer, Ö. Feyzi̇ Gürer, O. Meti̇n İlkişik, Ahmet T. Başokur
Turkish Journal of Earth Sciences
In the summer of 1995, magnetotelluric data were acquired at forty sites along a southwest-northeast profile crossing northwestern Turkey in continental Europe. The traverse, 204 km in length, crossed the boundary between a metamorphic mass called the Istranca Massif and a large Tertiary sedimentary basin called the Thrace Basin. The pseudosections of Mohr-circle-based rotational invariant characteristics of the magnetotelluric data such as central impedance (d3), anisotropy angle (l) and phase of central impedance (fd3) were prepared with classical magnetotelluric parameters (apparent resistivity and impedance phase), and detailed Mohr-circle displays were shown for selected stations as a function of the Bostick …
Helicity Dependence Of The \Vec\Gamma\Vec N \To \Pi N Reaction Channels In The \Delta-Resonance Region, Eed M. Darwish, Mohamed A. El-Zohry
Helicity Dependence Of The \Vec\Gamma\Vec N \To \Pi N Reaction Channels In The \Delta-Resonance Region, Eed M. Darwish, Mohamed A. El-Zohry
Turkish Journal of Physics
Based on a prior effective Lagrangian model on single pion photoproduction from the nucleon, successfully tested in total and differential cross sections, the helicity dependence from the interaction of circularly polarized photons and a longitudinally polarized nucleon target is studied in the energy range from \pi-threshold through the \Delta(1232)-resonance region. The doubly polarized total and differential cross section differences for parallel \sigma^{3/2} and antiparallel \sigma^{1/2} helicity states are predicted and compared with recent experimental data. We show that the results are sensitive to interferences among different contributions to the process and, thus, represent a complementary test of the theoretical model. …
Quasi Separation Axioms, Mohammad S. Sarsak
Quasi Separation Axioms, Mohammad S. Sarsak
Turkish Journal of Mathematics
In [5], Maheshwari et al. introduced and studied some new separation axioms, namely, quasi semi T_i axioms where i \in {0, 1, 2}, the quasi semi T_{1/2} axiom was then introduced and investigated by Gyu-Ihn et al. in [2]. In the present paper we introduce and study quasi T_i axioms, i \in {0, 1 / 2, 1, 2} as a special variety of quasi semi T_i axioms, the class of quasi T_{1/2} (respectively, quasi T_1) bitopological spaces is placed between quasi T_0 (respectively, quasi T_{1/2}) bitopological spaces and quasi T_1 (respectively, quasi T_2) bitopological spaces. Among several counter examples we …
Decompositions Of Continuity, Talal Al-Hawary, Ahmad Al-Omari
Decompositions Of Continuity, Talal Al-Hawary, Ahmad Al-Omari
Turkish Journal of Mathematics
In 2004, Al-Hawary and Al-Omari introduced and explored the class of \omega^o-open sets which is strictly stronger than the class of \omega-open sets and weaker than that of open sets. In this paper, we introduce what we call \omega^o-continuity and \omega_X^o-continuity and we give several characterizations and two decompositions of \omega ^o-continuity. Finally, new decompositions of continuity are provided.
A New Method For The Preparation Of Pyridazine Systems: Experimental Data And Semiempirical Pm3 Calculations, Di̇lek Ünal, Emi̇n Saripinar, Yunus Akçamur
A New Method For The Preparation Of Pyridazine Systems: Experimental Data And Semiempirical Pm3 Calculations, Di̇lek Ünal, Emi̇n Saripinar, Yunus Akçamur
Turkish Journal of Chemistry
The reactions of 4-benzoyl-5-phenyl-2,3-furandione (1a) and 4-(4-methoxybenzoyl)-5-(4-methoxyphenyl)-2,3-furandione (1b) with acyl hydrazines (2) (namely hydrazides) are reported. From these reactions, novel pyridazinone systems (3a-g) are obtained as well as the cyclization product of 3g at high temperature (4). The electronic properties and conformational parameters for these molecules, such as bond lengths, bond angles, torsion angles and atom charges, are calculated with a semiempirical PM3 method. In order to determine the mechanism of the reaction between the model furandion (R1) and formic hydrazide (R2), the electronic properties, conformational parameters and imaginary frequencies of the reactants, transition states and intermediates are calculated at …
The Calculations Of Oscillator Strengths And Transition Probabilities For Atomic Fluorine, Gülteki̇n Çeli̇k, H. Şükür Kiliç, Erhan Akin
The Calculations Of Oscillator Strengths And Transition Probabilities For Atomic Fluorine, Gülteki̇n Çeli̇k, H. Şükür Kiliç, Erhan Akin
Turkish Journal of Physics
Oscillator strengths for transitions between individual lines belonging to some doublet and quartet terms, and multiplet transition probabilities of atomic fluorine have been calculated using weakest bound electron potential model theory (WBEPMT). In the determination of relevant parameters, we employed numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii and the necessary energy values have been taken from experimental energy data in the literature. Oscillator strengths and transition probabilities obtained in this work have been compared to experimental and theoretical values given in the literature.
Solvent-Free Preparation Of Primary Carbamates, Ali Reza Modarresi-Alam, Mohsen Rostamizadeh, Parisa Najafi
Solvent-Free Preparation Of Primary Carbamates, Ali Reza Modarresi-Alam, Mohsen Rostamizadeh, Parisa Najafi
Turkish Journal of Chemistry
Herein, we describe a simple and efficient method for the conversion of compounds containing a hydroxyl group to primary carbamates at room temperature with excellent yield and purity, and without any epimerization, in the absence of solvent.
The Investigation Of Screening Of Chromoelectric And Chromomagnetic Fields In Noncovariant Gauges, Elşen Veli̇, Jale Yilmazkaya Süngü
The Investigation Of Screening Of Chromoelectric And Chromomagnetic Fields In Noncovariant Gauges, Elşen Veli̇, Jale Yilmazkaya Süngü
Turkish Journal of Physics
According to Thermal Quantum Chromodynamics (TQCD) hadron matter may exist in the form of quark-gluon plasma (QGP) at high temperatures and densities. The aim of the present work is to investigate the screening of chromoelectric and chromomagnetic fields in QGP in noncovariant gauges. In noncovariant gauges, gluon propagator has unphysical poles and singularities appear in the gluon self-energy diagram calculations. In this paper, we investigate gluon self-energy in lightcone and temporal gauges. In order to remove singularities, we use the Mandelstam-Leibbrandt prescription (ML prescription). We obtain that chromoelectric fields are screened, but chromomagnetic fields are not screened. In coordinate space, …
Investigation Of The Multipolarity Of Electromagnetic Transitions In ^{88,90}Kr Nuclei, Nuretti̇n Türkan, Davut Olgun, İhsan Uluer, Sai̇t İnan
Investigation Of The Multipolarity Of Electromagnetic Transitions In ^{88,90}Kr Nuclei, Nuretti̇n Türkan, Davut Olgun, İhsan Uluer, Sai̇t İnan
Turkish Journal of Physics
We have determined the most appropriate Hamiltonian that is needed for present calculations of nuclei about the A \cong 80 region by the view of Interacting Boson Model-2 (IBM-2). After obtaining the best Hamiltonian parameters, level energies and B(E2) probabilities of some transitions in ^{88,90}Kr nuclei were estimated. Results are compared with previous experimental and theoretical data and it is observed that they are in good agreement. Finally, R_1 = \frac{B(E2;4_1 \to 2_1)}{B(E2;2_1 \to 0_1)}, R_2 = \frac{B(E2;2_2 \to 2_1)}{B(E2;2_1 \to 0_1)}, \ R_3 = \frac{B(E2;0_2 \to 2_1)}{B(E2;2_1 \to 0_1)}, R_4 = \frac{{B(E2;2_2 \to 0_1)}{B(E2;2_2 \to 2_1)}, R_5 = \frac{B(E2;3_1 …
Peculiarities Of The Electric And Thermoelectric Properties Of Gate, M. M. Nassary
Peculiarities Of The Electric And Thermoelectric Properties Of Gate, M. M. Nassary
Turkish Journal of Physics
Measurements of electrical conductivity, Hall coefficient and thermoelectric power were carried out over the temperature range 136--563 K for GaTe compound grown in single crystal form by modified Bridgman technique. The crystals obtained had Positive-type conductivity with a hole concentration of 3.8 \times 10^{12} cm^{-3} at room temperature. Conductivity and Hall mobility at room temperature were evaluated as 4.4 \times 10^{-3} ohm^{-1} cm^{-1} and 7079 cm^2/V \cdot s, respectively. The energy gap width of 1.5 eV was found. The effective mass of holes and electrons at room temperature were 4.16 m_° and 0.1174 m_° , respectively
Rotating Disk Flow With Heat Transfer Of A Non Newtonian Fluid In Porous Medium, Hazem Ali Attia
Rotating Disk Flow With Heat Transfer Of A Non Newtonian Fluid In Porous Medium, Hazem Ali Attia
Turkish Journal of Physics
The steady flow of an incompressible viscous non-Newtonian fluid above an infinite rotating disk in a porous medium is studied with heat transfer. Numerical solutions of the nonlinear differential equations which govern the hydrodynamics and energy transfer are obtained. The effect of the porosity of the medium and the characteristics of the non-Newtonian fluid on the velocity and temperature distributions is considered.
Ramifications Of Lineland, Daniel Grumiller, Rene Meyer
Ramifications Of Lineland, Daniel Grumiller, Rene Meyer
Turkish Journal of Physics
A non-technical overview on gravity in two dimensions is provided. Applications discussed in this work comprise 2D type 0A/0B string theory, Black Hole evaporation/thermodynamics, toy models for quantum gravity, for numerical General Relativity in the context of critical collapse and for solid state analogues of Black Holes. Mathematical relations to integrable models, non-linear gauge theories, Poisson-sigma models, KdV surfaces and non-commutative geometry are presented.
Charges In Ads Spacetimes, İbrahi̇m Güllü, Bayram Teki̇n
Charges In Ads Spacetimes, İbrahi̇m Güllü, Bayram Teki̇n
Turkish Journal of Physics
We give a review of our recent work on conserved charges in cosmological spacetimes. We compute the mass and the angular momenta of various solutions in D dimensions. This is an extended version of a talk given by B. Tekin. The original material can be found in the related papers in our references.