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Full-Text Articles in Physical Sciences and Mathematics

On The Tautological Ring Of \Bar{\Mathcal{M}}_{G,N}, Tom Graber, Ravi Vakil Jan 2001

On The Tautological Ring Of \Bar{\Mathcal{M}}_{G,N}, Tom Graber, Ravi Vakil

Turkish Journal of Mathematics

We prove that the dimension 0 part of the tautological ring of the moduli space of stable pointed curves is one-dimensional. This provides the first genus-free evidence for a conjecture of Faber and Pandharipande that the tautological ring of the moduli space is Gorenstein, answering in the affirmative a question of Hain and Looijenga.


Formula For The Highly Regularized Trace Of The Sturm-Liouville Operator With Unbounded Operator Coefficients Having Singularity, İnci̇ Albayrak, Oya Baykal, Erdal Gül Jan 2001

Formula For The Highly Regularized Trace Of The Sturm-Liouville Operator With Unbounded Operator Coefficients Having Singularity, İnci̇ Albayrak, Oya Baykal, Erdal Gül

Turkish Journal of Mathematics

In this work, a formula for the n^{th} regularized trace of the Sturm-Liouville operator with unbounded operator coefficients having singularity is obtained


Remarks On The Paper "On The Commutant Of The Ideal Centre", Şafak Alpay, Bahri̇ Turan Jan 2001

Remarks On The Paper "On The Commutant Of The Ideal Centre", Şafak Alpay, Bahri̇ Turan

Turkish Journal of Mathematics

We continue with the work started in [4] and give a new sufficient condition on Riesz spaces having topologically full centres for Z^{\sim}(E)_C=Orth(E^{\sim}) to hold.


On The Centroid Of The Prime Gamma Rings Ii, Mehmet Ali̇ Öztürk, Young Bae Jun Jan 2001

On The Centroid Of The Prime Gamma Rings Ii, Mehmet Ali̇ Öztürk, Young Bae Jun

Turkish Journal of Mathematics

The aim of this paper is to study the properities of the extended centroid of the prime \Gamma-rings. Main results are the following theorems: (1) Let M be a simple \Gamma-ring with unity. Suppose that for some a\neq 0 in M we have a\gamma_{1} x\gamma_{2} a\beta_{1} y\beta_{2}a = a\beta_{1} y\beta_{2} a\gamma_{1} x\gamma_{2}a for all x, y\in M and \gamma_{1} ,\gamma_{2} ,\beta_{1} ,\beta_{2} \in \Gamma. Then M is isomorphic onto the \Gamma-ring D_{n,m}, where D_{n,m} is the additive abelian group of all rectangular matrices of type n\times m over a division ring D and \Gamma is a nonzero subgroup of the …


Characterizations Of Matroid Via Ofr-Sets, Talal Ali̇ Al-Hawary Jan 2001

Characterizations Of Matroid Via Ofr-Sets, Talal Ali̇ Al-Hawary

Turkish Journal of Mathematics

The aim of this paper is to introduce the class of OFR-sets as the sets that are the intersection of an open set and a feeble-regular set. Several classes of matroids are studied via the new concept. New decompositions of strong maps are provided.


Diagonal Lift In The Cotangent Bundle And Its Applications, Sezgi̇n Akbulut, Murat Özdemi̇r, Ari̇f A. Salimov Jan 2001

Diagonal Lift In The Cotangent Bundle And Its Applications, Sezgi̇n Akbulut, Murat Özdemi̇r, Ari̇f A. Salimov

Turkish Journal of Mathematics

The purpose of this paper is to define a diagonal lift ^{\mathcal{D }}g of a Riemannian metric g of a manifold M_{n} to the cotangent bundle T^{*}(M_{n}) of M_{n}, to associate with ^{\mathcal{D}}g an Levi-Civita connection of T^{*}(M_{n}) in a natural way and to investigate applications of the diagonal lifts.


Accurate Parameter Estimation For An Articulatory Speech Synthesizer With An Improved Neural Network Mapping, Hali̇s Altun, Tankut Yalçinöz, K. Mervyn Curtis Jan 2001

Accurate Parameter Estimation For An Articulatory Speech Synthesizer With An Improved Neural Network Mapping, Hali̇s Altun, Tankut Yalçinöz, K. Mervyn Curtis

Turkish Journal of Electrical Engineering and Computer Sciences

Neural network (NN) applications have recently been employed to extract the parameters of an articulatory speech synthesizer from a given speech signal. Results from these attempts showed that a single NN is insufficient to cover all of the possible configurations uniquely. Moreover, apart from their computational advantages, NN mapping is so far not superior to the other mapping techniques [1]. Thus there is a clear need to improve NN solution to the inverse problem. Results from our earlier experiments with an articulatory speech synthesizer have shown that the statistical characteristic of the articulatory target pattern vectors can be exploited for …


Ota-C Based Proportional-Integral-Derivative (Pid) Controller And Calculating Optimum Parameter Tolerances, Cevat Erdal, Ali̇ Toker, Cevdet Acar Jan 2001

Ota-C Based Proportional-Integral-Derivative (Pid) Controller And Calculating Optimum Parameter Tolerances, Cevat Erdal, Ali̇ Toker, Cevdet Acar

Turkish Journal of Electrical Engineering and Computer Sciences

Proportional-integral-derivative (PID) controllers are one of the most important control elements used in the process control industry. In practice, operational amplifiers are generally used in analog controllers. On the other hand, the operational transconductance amplifiers recently developed, which have some positive properties compared to operational amplifiers, are not used in analog controller design at present. Furthermore, the optimum parameter tolerances for the proposed PID circuit by the use of parameter sensitivities are determined. These tolerances keep the relative error at the output of the controller due to parameter variations in the tolerance region.


Combining Multiple Representations For Pen-Based Handwritten Digit Recognition, Fevzi̇ Ali̇moğlu, Ethem Alpaydin Jan 2001

Combining Multiple Representations For Pen-Based Handwritten Digit Recognition, Fevzi̇ Ali̇moğlu, Ethem Alpaydin

Turkish Journal of Electrical Engineering and Computer Sciences

We investigate techniques to combine multiple representations of a handwritten digit to increase classification accuracy without significantly increasing system complexity or recognition time. In pen-based recognition, the input is the dynamic movement of the pentip over the pressure sensitive tablet. There is also the image formed as a result of this movement. On a real-world database of handwritten digits containing more than 11,000 handwritten digits, we notice that the two multi-layer perceptron (MLP) based classifiers using these representations make errors on different patterns implying that a suitable combination of the two would lead to higher accuracy. We implement and compare …


Fuzzy Modeling Approach For Integrated Assessments Using Cultural Theory, Adnan Yazici, Fred E. Petry, Curt Pendergraft Jan 2001

Fuzzy Modeling Approach For Integrated Assessments Using Cultural Theory, Adnan Yazici, Fred E. Petry, Curt Pendergraft

Turkish Journal of Electrical Engineering and Computer Sciences

It has already been noted that the accurate prediction of societal responses requires the use of a formal model based on some social or cultural taxonomy. One such taxonomic candidate is Cultural Theory (CT). CT argues that all societies, irrespective of time or place, are informed by their underlying worldviews, which must be more or less Hierarchic, more or less Individualistic, more or less Egalitarian, and more or less Fatalistic. This approach appears to have a potential for cross-temporal and spatial comparisons that makes it a particularly attractive instrument for a study of the human dimensions of global climate change. …


A More Efficient Design And Implementation Of Cal Programs In Natural Science Using Object-Oriented Technology, Jurgen Friedrich Jan 2001

A More Efficient Design And Implementation Of Cal Programs In Natural Science Using Object-Oriented Technology, Jurgen Friedrich

Turkish Journal of Electrical Engineering and Computer Sciences

With the amount and complexity of science topics and applications increasing, the need for appropriate and effective science education is constantly growing. Computer-based education is very promising to help both teachers and learners in their difficult task, which involves complex psychological processes. This complexity is reflected in high demands on the design and implementation methods used to create computer-assisted learning (CAL) programs. Due to their concepts, flexibility, maintainability and extended library resources, object-oriented technology (OOT) is very suitable to producing this type of pedagogical tool. The introduced approach is demonstrated by a basketball simulation program for instruction in Newtonian mechanics …


Upper Cretaceous Eclogite-Facies Metamorphic Rocks From The Biga Peninsula, Northwest Turkey, Aral İ. Okay, Muharrem Satir Jan 2000

Upper Cretaceous Eclogite-Facies Metamorphic Rocks From The Biga Peninsula, Northwest Turkey, Aral İ. Okay, Muharrem Satir

Turkish Journal of Earth Sciences

Medium-grade metamorphic rocks crop out over a large area under the Neogene sedimentary and volcanic rocks in the central Biga Peninsula in northwest Turkey. These Çamlıca metamorphics consist dominantly of quartz-micaschists with minor calc-schist, marble, quartzite and metabasite. Some of the metabasites in the Çamlıca metamorphics preserve an early eclogite-facies mineral assemblage of garnet + omphacite + glaucophane + rutile ± paragonite, strongly overprinted by greenschist-facies mineral assemblages. The conditions of the eclogite-facies metamorphism have been determined as 510 ± 50°C temperatures and a minimum pressure of 11 kbar, based on the garnet-clinopyroxene Fe-Mg partitioning and the jadeite content of …


Biostratigraphic Data (Mammalia And Palynology) From The Upper Miocene İncesu Formation At Düzyayla (Hafik-Sivas, Central Anatolia), Funda Akgün, Tanju Kaya, Ann Forsten, Zeki̇ Atalay Jan 2000

Biostratigraphic Data (Mammalia And Palynology) From The Upper Miocene İncesu Formation At Düzyayla (Hafik-Sivas, Central Anatolia), Funda Akgün, Tanju Kaya, Ann Forsten, Zeki̇ Atalay

Turkish Journal of Earth Sciences

The Upper Miocene İncesu formation, widely exposed in Düzyayla (Hafik-Sivas), consists of mudstones, conglomerates, lacustrine limestones and lignite. The İncesu formation overlies the gypsiferous Hafik formation of controversial Middle Miocene or Oligocene ages. The mammalian fauna of the lignite horizon includes Hipparion sp., Ceratotherium neumayri (Osborn), Deinotherium giganteum Kaup, Choerolophodon pentelici (Gaudry & Lartet), Adcrocuta cf. eximia (Roth & Wagner), Oioceros wegneri Andree, Helladotherium duvernoyi Gaudry & Lartet and Microstonyx erymanthius (Roth & Wagner), which indicate a Turolian (Late Miocene) age. The palynological assemblage of the lignite is apparently represented by 27 genera and 39 species. Four genera and four …


A Special Quasi-Linear Mapping And Its Degree, Aki̇f Abbasov Jan 2000

A Special Quasi-Linear Mapping And Its Degree, Aki̇f Abbasov

Turkish Journal of Mathematics

In this article, for the purpose of expanding to the mappings between Banach manifolds, a degree is determined in for the mappings between Banach spaces, which are from the obvious class.


Strongly Prime Ideals In Cs-Rings, Gonca Güngöroğlu Jan 2000

Strongly Prime Ideals In Cs-Rings, Gonca Güngöroğlu

Turkish Journal of Mathematics

We study and characterize strongly prime right ideals in CS-rings.


On Non-Homogeneous Riemann Boundary Value Problem, Kadi̇r Kutlu Jan 2000

On Non-Homogeneous Riemann Boundary Value Problem, Kadi̇r Kutlu

Turkish Journal of Mathematics

In this paper we consider non-homogeneous Riemann boundary value problem with unbounded oscillating coefficients on a class of open rectifiable Jordan curve.


On The Linearity Of Certain Mapping Class Groups, Mustafa Korkmaz Jan 2000

On The Linearity Of Certain Mapping Class Groups, Mustafa Korkmaz

Turkish Journal of Mathematics

S. Bigelow proved that the braid groups are linear. That is, there is a faithful representation of the braid group into the general linear group of some field. Using this, we deduce from previously known results that the mapping class group of a sphere with punctures and hyperelliptic mapping class groups are linear. In particular, the mapping class group of a closed orientable surface of genus $2$ is linear.


An Extended Adiabatic Approach For Nuclear Reactions, Mustafa Yilmaz, Bülent Gönül Jan 2000

An Extended Adiabatic Approach For Nuclear Reactions, Mustafa Yilmaz, Bülent Gönül

Turkish Journal of Physics

In this letter, an alternative approximation is developed for the treatment of breakup process in nuclear reactions, which presents a way of evaluating non-adiabatic corrections to the adiabatic model three-body wavefunction by introducing a more consistent prescription for the continuum n-p center of mass energy. Although the present formalism goes beyond the quasi-adiabatic approach, due to the use of exact continuum channel energies, its application to deuteron involving reactions at medium energies shows that such an approach can not be used in its present form. A possible reason behind this failure is discussed.


Microhardness Creep In Single Crystals Of Tin-Chalcogenides, S. M. Vyas, C. F. Desai, R. C. Shah, G. R. Pandya Jan 2000

Microhardness Creep In Single Crystals Of Tin-Chalcogenides, S. M. Vyas, C. F. Desai, R. C. Shah, G. R. Pandya

Turkish Journal of Physics

SnSe and SnS have been grown by Bridgman- Stockbarger method. Loading time as a function of vickers microhardness has been measured at different temperatures in the range 303 K to 388K. Al measurement of hardness have been carried out on the cleavage planes. The activation energy for creep has been evaluated to be 2.92 and 1.75 K Cal/mole, respectively, for SnSe and SnS crystals.


The Lattice Dynamics Of Bcc Titanium, Kemal Çolakoğlu, Yasemi̇n Özteki̇n Çi̇ftçi̇ Jan 2000

The Lattice Dynamics Of Bcc Titanium, Kemal Çolakoğlu, Yasemi̇n Özteki̇n Çi̇ftçi̇

Turkish Journal of Physics

Using in measurements of the phonon frequencies of bcc Titanium, the lattice dynamical calculations are performed on the same phase by using the Third-neighbour Clark-Gazis-Wallis(CGW) model. The theory is used to compute the phonon dispersion curves, the frequency spectra and the lattice spesific heat of the studied phase. The obtained results are compared with the available experimental data.


Properties Of Ag-Doped Bi_{(1.6)}Pb_{(0.4)}Sr_2ca_3cu_{(4-X)}Ag_Xo_Y (2234) Oxides Prepared By S.S.R. Method, Süleyman Bolat, E. Yanmaz, H. Cömert Jan 2000

Properties Of Ag-Doped Bi_{(1.6)}Pb_{(0.4)}Sr_2ca_3cu_{(4-X)}Ag_Xo_Y (2234) Oxides Prepared By S.S.R. Method, Süleyman Bolat, E. Yanmaz, H. Cömert

Turkish Journal of Physics

The effect of Ag-doping Bi$_{1.6}$Pb$_{0.4}$Sr$_{2}$Ca$_{3}$Cu$_{4-x}$Ag$_{x}$O$_{y}$ compounds (x=0.0-1.0), prepared by conventional Solid-State-Reaction (SSR) technique, was studied using x-ray diffraction (XRD) and electrical resistivity. The high-T$_{c}$ fraction of the 2223 phase, formed from the nominal composition of 2234, decreases with increasing Ag content. From lattice parameter calculations it follows that Ag-doping the unit cell phase of (Bi,Pb)$_{2}$Sr$_{2}$Ca$_{2}$Cu$_{3}$O$_{y}$ is limited to the value of x$\leq$0.1. The zero resistance critical temperature (T$_{c,zero}$) was determined from the resistivity curves for all samples. The value of T$_{c,zero}$ decreases slightly to 106 K for x$\leq$0.4 and when the nominal silver content increases up to x=0.7 or more …


Multi-Species Asymmetric Exclusion Process In Ordered Sequential Update, M. Ebrahi̇m Fouladvand, Farhad Jafarpour Jan 2000

Multi-Species Asymmetric Exclusion Process In Ordered Sequential Update, M. Ebrahi̇m Fouladvand, Farhad Jafarpour

Turkish Journal of Physics

A multi-species generalization of the asymmetric simple exclusion process (ASEP) is studied in ordered sequential and sub-lattice parallel updating schemes. In this model, particles hop with their own specific probabilities to their rightmost empty site and fast particles overtake slow ones with a definite probability. Using Matrix Product Ansatz (MPA), we obtain the relevant algebra, and study the uncorrelated stationary state of the model both for an open system and on a ring. A complete comparison between the physical results in these updates and those of random sequential introduced in [20,21] is made.


Product Integral Representations Of Wilson Lines And Wilson Loops And Non-Abelian Stokes Theorem, Robert L. Karp, Freydoon Mansouri, Jung S. Rno Jan 2000

Product Integral Representations Of Wilson Lines And Wilson Loops And Non-Abelian Stokes Theorem, Robert L. Karp, Freydoon Mansouri, Jung S. Rno

Turkish Journal of Physics

We make use of product integrals to provide an unambiguous mathematical representation of Wilson line and Wilson loop operators. Then, drawing upon various properties of product integrals, we discuss such properties of Wilson lines and Wilson loops as approximating them with partial sums, their convergence, and their behavior under gauge transformations. We also obtain a surface product integral representation for the Wilson loop operator. The result can be interpreted as the non-abelian version of Stokes theorem.


Associations Of X-Ray Binaries With Open Clusters And Supernova Remnants, Eni̇s Tuncer, H. Guseinov, Ü. Kiziloğlu, A. O. Allakhverdiev Jan 2000

Associations Of X-Ray Binaries With Open Clusters And Supernova Remnants, Eni̇s Tuncer, H. Guseinov, Ü. Kiziloğlu, A. O. Allakhverdiev

Turkish Journal of Physics

Searching for X-ray binaries projected on open clusters (OCs) and supernova remnants (SNRs), associations of X-ray binaries with OCs and SNRs in the Galaxy are discussed. Three of the high mass X-ray binaries (HMXBs) and four of the low mass X-ray binaries (LMXBs) are projected on open clusters. Five of HMXBs and six of LMXBs are projected on SNRs. The number of the HMXB projections are less than the LMXBs, which is not expected and is surprising since the objects in this study, except the LMXBs, are all young objects. Such associations help us improve distance and age estimates of …


Ferromagnetic Transitions In Ni-Mn Alloys, F. Boakye, R. K. Nkum Jan 2000

Ferromagnetic Transitions In Ni-Mn Alloys, F. Boakye, R. K. Nkum

Turkish Journal of Physics

Ferromagnetic transitions in nickel and nickel-manganese alloys have been studied using resistivity-temperature measurements from 800 to 77 K. The results establish the transition temperature of nickel as 610 K and the transition temperature is shifted to lower values as the concentration of Mn in the alloy is increased. Analysis of the resistivity results near the ordering temperature \( (T


Radioluminescent Properties Of Cds(Ag) Crystals, Ruhi̇ Kaplan, F. Esen Özsan Jan 2000

Radioluminescent Properties Of Cds(Ag) Crystals, Ruhi̇ Kaplan, F. Esen Özsan

Turkish Journal of Physics

The radioluminescent proporties of silver-doped cadmium sulphide, CdS(Ag), crystals excited by 5.5 MeV $ \alpha $-particles from an $ ^{241}$Am radioactive source have been investigated. The emission spectra, decay profiles and thermal quenching curves were obtained accurately at temperatures between 80 K and 300 K. Two main radioluminescent emission bands centered at about 5760 \AA\ and 5940 \AA\ were observed. Their decay curves were found to be fast and nonexponential. From the thermal quenching of radioluminescence, the activation energies of centers responsible for these emissions were determined. The results are interpreted as the radioluminescence is possibly due to donor-acceptor pair …


Late Devonian Conodont Fauna Of The Gümüşali Formation, The Eastern Taurides, Turke, Şenol Çapkinoğlu, İsmet Gedi̇k Jan 2000

Late Devonian Conodont Fauna Of The Gümüşali Formation, The Eastern Taurides, Turke, Şenol Çapkinoğlu, İsmet Gedi̇k

Turkish Journal of Earth Sciences

The Late Devonian Gümüşali formation of the eastern Taurides is a terrigenous-carbonate rock sequence about 600 m thick, consisting mainly of quartz sandstone, quartz siltstone, shale, and carbonate rocks. Palaeontologic and sedimentologic data mainly indicate a shallow subtidal depositional environment. This sequence generally represents the shallow-water polygnathid-icriodid biofacies, and contains conodont faunas that range from the Upper falsiovalis Zone into the Upper praesulcata Zone. However, they do not correlate well to the Late Devonian standard conodont zonation because of the lack of zonally diagnostic species and the irregular vertical distributions of the present taxa. Herein, 54 taxa belonging to nine …


Late Devonian (Famennian) Conodonts From Denizliköyü, Gebze, Kocaeli, Northwestern Turkey, Şenol Çapkinoğlu Jan 2000

Late Devonian (Famennian) Conodonts From Denizliköyü, Gebze, Kocaeli, Northwestern Turkey, Şenol Çapkinoğlu

Turkish Journal of Earth Sciences

Late Devonian (Famennian) conodont faunas have been described from two incomplete stratigraphic sections (GD and GB) of the Ayineburnu member of the Tuzla formation, Denizliköyü, Gebze, Kocaeli, northwestern Turkey. The section GD comprises the Lower and Middle expansa Zones, and the section GB contains the Middle and Upper expansa Zones. Zonal indices for the Middle expansa Zone are identified in the section GB, whereas this zone is recognized on the basis of other key taxa in the section GD. Also, a new species of the Genus Branmehla, Branmehla gediki n.sp. is described from the section GD.


A Glancing Incidence Exafs Study Of Evaporated Silver Films On Glass, Ahmet Bulut, Bünyami̇n Karabulut, Engi̇n Başaran, James Robinson Jan 2000

A Glancing Incidence Exafs Study Of Evaporated Silver Films On Glass, Ahmet Bulut, Bünyami̇n Karabulut, Engi̇n Başaran, James Robinson

Turkish Journal of Physics

A glancing incidence EXAFS experiment has been carried out with evaporated silver films on glass substrates. Prior to EXAFS data collection, a reflectivity curve was performed from which the critical angle for total external reflection of x-rays from surface were determined. The analysed EXAFS data revealed that there is a reduction in the coordination number and an increase in Debye-Waller factor compared to bulk values. These changes were explained in terms of grain size effect and the surface effects of the silver film.


Consistency Of The Born Approximation For Aharonov-Bohm Scattering With Massless Spin-1/2 Particles, Müge Boz, Namik Kemal Pak Jan 2000

Consistency Of The Born Approximation For Aharonov-Bohm Scattering With Massless Spin-1/2 Particles, Müge Boz, Namik Kemal Pak

Turkish Journal of Physics

The second order contribution for the relativistic scattering of massless spin-$\frac{1}{2}$ particles from an infinitely long solenoid, in the context of covariant perturbation theory, is calculated and shown to vanish. Thus, Born approximation is consistent for this case as well.