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Full-Text Articles in Physical Sciences and Mathematics

A Corpus-Based Concatenative Speech Synthesis System For Turkish, Haşi̇m Sak, Tunga Güngör, Yaşar Safkan Jan 2006

A Corpus-Based Concatenative Speech Synthesis System For Turkish, Haşi̇m Sak, Tunga Güngör, Yaşar Safkan

Turkish Journal of Electrical Engineering and Computer Sciences

Speech synthesis is the process of converting written text into machine-generated synthetic speech. Concatenative speech synthesis systems form utterances by concatenating pre-recorded speech units. Corpus-based methods use a large inventory to select the units to be concatenated. In this paper, we design and develop an intelligible and natural sounding corpus-based concatenative speech synthesis system for the Turkish language. The implemented system contains a front-end comprised of text analysis, phonetic analysis, and optional use of transplanted prosody. The unit selection algorithm is based on commonly used Viterbi decoding algorithm of the best-path in the network of the speech units using spectral …


Speech Pre-Processing For Pitch And Pitch-Cylce Evolutions Smoothing, Hassan Farsi Jan 2006

Speech Pre-Processing For Pitch And Pitch-Cylce Evolutions Smoothing, Hassan Farsi

Turkish Journal of Electrical Engineering and Computer Sciences

In low bit rate speech coders, pitch is usually transmitted once per frame and, when needed, the intermediate pitch values are obtained by interpolation between 2 adjacent pitch values. Although pitch usually evolves slowly, sometimes it has irregular variations and the estimated pitch differs from the real one. In addition, some speech coders, e.g., waveform interpolation coders, rely on smooth pitch-cycle evolutions to extract speech model parameters in the analysis stage. However, non-stationary characteristics of speech may lead to inaccurate estimation of the parameters. This affects the synthesised speech quality. We propose a pre-processor, which modifies the residual speech signal …


A Pi Controller Based On Gain-Scheduling For Synchronous Generator, Alireza Sedaghati Jan 2006

A Pi Controller Based On Gain-Scheduling For Synchronous Generator, Alireza Sedaghati

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a gain- scheduling scheme of a proportional integral (GSPI) controller is proposed for a synchronous generator. In presented scheme, both proportional and integral gains are allowed to vary within a predetermined range. In order to validate the effectiveness of GSPI controller, simulation studies for a single-machine infinite bus power system are used .The results verify improved performance of GSPI controller comparing to conventional AVR under various operating conditions.


Adaptive 3d Visual Servo Control Of Robot Manipulators Via Composite Camera Inputs, Türker Şahi̇n, Erkan Zergeroğlu Jan 2006

Adaptive 3d Visual Servo Control Of Robot Manipulators Via Composite Camera Inputs, Türker Şahi̇n, Erkan Zergeroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper considers the problem of position control of robot manipulators via visual servoing in the presence of uncertainty associated with the robot dynamics and the vision system. Specifically, an adaptive controller is designed to compensate for the uncertainties associated with the mechanical parameters of the robot manipulator and the intrinsic parameters of the cameras. The 3D visual information is obtained from the composite inputs of two separate cameras placed in the robot work space. Despite the uncertainties associated with the camera system and robot dynamics the proposed adaptive controller achieves asymptotic end effector position tracking. A Lyapunov based approach …


Uplink Practical Capacity And Interference Statistics Of Wcdma Cigar-Shaped Microcells For Highways In Rural Zones With Non-Uniform Spatial Traffic Distribution And Imperfect Power Control, Bazil Taha Ahmed, Miguel Calvo Ramon, Leandro De Haro-Ariet Jan 2006

Uplink Practical Capacity And Interference Statistics Of Wcdma Cigar-Shaped Microcells For Highways In Rural Zones With Non-Uniform Spatial Traffic Distribution And Imperfect Power Control, Bazil Taha Ahmed, Miguel Calvo Ramon, Leandro De Haro-Ariet

Turkish Journal of Electrical Engineering and Computer Sciences

The capacity (the maximum number of users per sector that the system can support) and the interference statistics (expected value and variance) of sectors composed of cigar-shaped WCDMA microcells are studied. A model of 5 microcells is used to analyze the uplink capacity and interference statistics. The microcells are assumed to exist in rural zone highways. The capacity and the interference statistics of the microcells are studied for different non-uniform spatial traffic distributions. As user density decreases away from the base station, the capacity of the sector increases due to the reduced total power transmitted by the interfering users.


An Ann Based Approach To Improve The Distance Relaying Algorithm, Hassan Khorashadi Zadeh, Zuyi Li Jan 2006

An Ann Based Approach To Improve The Distance Relaying Algorithm, Hassan Khorashadi Zadeh, Zuyi Li

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an artificial neural network- (ANN) based approach to improve the performance of the distance relaying algorithm. The proposed distance relay uses magnitudes of voltages and currents as input signals to find fault locations. In this approach, an ANN has been included in the protection algorithm as an extension of the existing methods, which improves the reliability of the protection operation. The design procedure of the proposed relay is presented in detail. Simulation studies are performed and the influence of changing system parameters, such as fault resistance and source impedance, is studied. Performance studies show that the proposed …


State Of The Art For Differential Circuits In Wireless Transceivers: A New Wideband Active Balun In Sige Bicmos Technology, Balwant Godara, Alain Fabre Jan 2006

State Of The Art For Differential Circuits In Wireless Transceivers: A New Wideband Active Balun In Sige Bicmos Technology, Balwant Godara, Alain Fabre

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is 3-fold: firstly, to provide a comprehensive overview of the use of differential circuits for analogue signal processing in wireless transceivers; secondly, to describe, in detail, single-ended signal to differential conversion, and the corresponding theory of such devices, their characterisation, various methods of implementation, and comparative analyses of their performance; lastly, to propose a new transistor-based solution for wideband baluns. This novel solution is based on the current conveyor and has been modelled using the transistor parameters of a 0.35 \mu m SiGe BiCMOS technology. The salient features of the new implementation are: (a) stable …


Statistical Model Of Hot-Carrier Degradation And Lifetime Prediction For P-Mos Transistors, Firat Kaçar, Ayten Kuntman, Hakan Kuntman Jan 2006

Statistical Model Of Hot-Carrier Degradation And Lifetime Prediction For P-Mos Transistors, Firat Kaçar, Ayten Kuntman, Hakan Kuntman

Turkish Journal of Electrical Engineering and Computer Sciences

Along with advances in microelectronics, and computer and space technologies, device dimensions are becoming smaller; as a result, hot-carrier effect, lifetime prediction, and reliability become more important concepts for MOS transistors. In this paper, the degradation in the drain current and threshold voltage of P-MOS transistors are observed by operating the devices under voltage stress conditions. Using the observation results, the effect of hot-carriers was investigated statistically and a new statistical method for modeling was proposed as an alternative to those given in the literature. The linear regression method is used to estimate the power, Weibull, and logarithmic parameters, and …


The Effect Of Collector Doping On Inp-Based Double Heterojunction Bipolar Transistors, Serkan Topaloğlu, Jörn Driesen, Werner Prost, Franz Josef Tegude Jan 2006

The Effect Of Collector Doping On Inp-Based Double Heterojunction Bipolar Transistors, Serkan Topaloğlu, Jörn Driesen, Werner Prost, Franz Josef Tegude

Turkish Journal of Electrical Engineering and Computer Sciences

High current effects on double heterojunction bipolar transistor (DHBT) performance were investigated. Three DHBTs with different collector doping densities were grown and processed. DC and RF measurements were performed to evaluate the influence of collector doping and the related Kirk effect on HBT performance. In addition to these samples, the Kirk effect was proven on SHBTs and the delay of this effect on submicron HBTs was investigated.


An Adaptive Feedforward Amplifier Application For 5.8 Ghz, Engi̇n Kurt, Osman Palamutçuoğullari Jan 2006

An Adaptive Feedforward Amplifier Application For 5.8 Ghz, Engi̇n Kurt, Osman Palamutçuoğullari

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a 5.8 GHz power amplifier is linearized by an adaptive feedforward technique. A DSP-based control scheme is applied to reduce the intermodulation distortion of this amplifier. A two-tone test is used to verify the design.


Artificial Neural Design Of Microstrip Antennas, Nurhan Türker, Fi̇li̇z Güneş, Tülay Yildirim Jan 2006

Artificial Neural Design Of Microstrip Antennas, Nurhan Türker, Fi̇li̇z Güneş, Tülay Yildirim

Turkish Journal of Electrical Engineering and Computer Sciences

A general design procedure is suggested for microstrip antennas using artificial neural networks and this is demonstrated using rectangular patch geometry. In this design procedure, synthesis is defined as the forward side and then analysis as the reverse side of the problem. Worked examples are given using the most efficient materials.


Wind Power, Distributed Generation: New Challenges, New Solutions, Vladimiro Miranda Jan 2006

Wind Power, Distributed Generation: New Challenges, New Solutions, Vladimiro Miranda

Turkish Journal of Electrical Engineering and Computer Sciences

This paper discusses some issues related with the growing importance of wind power and in modern power systems and some challenges raised by the emergence of distributed generation, and how computational intelligence and other modern techniques have been able to provide valuable results in solving the new problems. It presents some solutions obtained with a number of computational intelligence techniques and their application to real cases.


Asymptotic Formulas For The Resonance Eigenvalues Of The Schrödinger Operator, Sedef Karakiliç, O. A. Veli̇ev, Ş. Atilgan Jan 2005

Asymptotic Formulas For The Resonance Eigenvalues Of The Schrödinger Operator, Sedef Karakiliç, O. A. Veli̇ev, Ş. Atilgan

Turkish Journal of Mathematics

In this paper, we consider the Schrödinger operators defined by the differential expression Lu= - \Delta u + q(x)u in d-dimensional paralellepiped F, with the Dirichlet and the Neumann boundary conditions, where q(x) is a real valued function of L_2(F). We obtain the asymptotic formulas for the resonance eigenvalues of these operators


The Basis Number Of The Semi-Composition Product Of Some Graphs I, M. M. Jaradat, E. A. Rawashdeh, M. Y. Alzoubi Jan 2005

The Basis Number Of The Semi-Composition Product Of Some Graphs I, M. M. Jaradat, E. A. Rawashdeh, M. Y. Alzoubi

Turkish Journal of Mathematics

The basis number of a graph G is defined to be the least integer d such that there is a basis \mathcal{B} of the cycle space of G such that each edge of G is contained in at most d members of \mathcal{B}. We investigate the basis number of the semi-composition product of two paths and a cycle with a path.


Self-Adjoint Boundary Value Problems On Time Scales And Symmetric Green's Functions, Gusein Sh. Guseinov Jan 2005

Self-Adjoint Boundary Value Problems On Time Scales And Symmetric Green's Functions, Gusein Sh. Guseinov

Turkish Journal of Mathematics

In this note, higher order self-adjoint differential expressions on time scales, and associated with them self-adjoint boundary conditions, are discussed. The symmetry peoperty of the corresponding Green's functions is emphasized.


On Groups With The Weak Wide Commensurable Property, Ayşe Berkman, Mahmut Kuzucuoğlu, Erdal Özyurt Jan 2005

On Groups With The Weak Wide Commensurable Property, Ayşe Berkman, Mahmut Kuzucuoğlu, Erdal Özyurt

Turkish Journal of Mathematics

An infinite group with the weak wide commensurable property is shown to be abelian, provided that it is locally finite or locally graded or non-perfect or linear. We also investigate the properties of infinite non-abelian groups with the weak wide commensurable property. Moreover, we describe completely the structure of infinite locally finite groups whose p-subgroups have the weak wide commensurable property. (AMS MSC: 20F50, 20E34).


Valuations Of Polynomials, Sorasak Leeratanavalee Jan 2005

Valuations Of Polynomials, Sorasak Leeratanavalee

Turkish Journal of Mathematics

A tree is a connected (undirected) graph that contains no cycles. Trees play an important role in Computer Science. There are many applications in this field. Ordered binary decision diagrams are trees in the language of Boolean algebras. For the applications, it is important to measure the complexity of a tree or of a polynomial. The complexity of a polynomial over an arbitrary algebra can be regarded as a valuation. The concept of the valuations of terms was introduced by K. Denecke and S. L. Wismath in [5]. In [6], the author defined the depth of a polynomial which is …


Corrigendum Uniqueness Of Primary Decompositions [Turkish J. Math. 27 (2003), 425--434], Patrick F. Smith Jan 2005

Corrigendum Uniqueness Of Primary Decompositions [Turkish J. Math. 27 (2003), 425--434], Patrick F. Smith

Turkish Journal of Mathematics

No abstract provided.


Maximum Entropy-Based Fuzzy Clustering By Using L_1-Norm Space, Mohammad Ghorbani Jan 2005

Maximum Entropy-Based Fuzzy Clustering By Using L_1-Norm Space, Mohammad Ghorbani

Turkish Journal of Mathematics

One of the most important methods in analysis of large data sets is clustering. These methods are not only major tools to uncover the underlying structures of a given data set, but also promising tools to uncover local input-output relations of a complex system. The goal of this paper is to present a new approach to fuzzy clustering by using L_1-norm space by means of a maximum entropy inference method, where, firstly, the resulting formulas have more beautiful form and clearer physical meaning than those obtained by means of FCM method and secondly, the obtained criteria by this new method …


Formulas For The Fourier Coefficients Of Cusp Form For Some Quadratic Forms, Ahmet Tekcan Jan 2005

Formulas For The Fourier Coefficients Of Cusp Form For Some Quadratic Forms, Ahmet Tekcan

Turkish Journal of Mathematics

In this paper, representations of positive integers by certain quadratic forms Q_p defined for odd prime p are examined. The number of representations of positive integer n by the quadratic form Q_p, is denoted by r(n;Q_p), obtained for p=3,5 and 7.\thinspace We prove that r(n;Q_p)=\rho (n;Q_p)+\vartheta (n;Q_p) for p=3,5 and 7, where \rho (n;Q_p) is the singular series and \vartheta (n;Q_p) is the Fourier coefficient of cusp form.


2-Quasi-\Lambda-Nuclear Maps, Wasfi Shatanawi Jan 2005

2-Quasi-\Lambda-Nuclear Maps, Wasfi Shatanawi

Turkish Journal of Mathematics

In this paper we generalize the well-known result which says that the composition of quasi-nuclear maps is nuclear. More precisely, we define what we call a 2-quasi-\lambda -nuclear map between normed spaces, and we prove that the composition of a 2-quasi-\lambda -nuclear map with a quasi- \lambda -nuclear map is a pseudo-\lambda -nuclear map. Also, we prove that a quasi-\lambda -nuclear map is a 2-quasi-\lambda -nuclear map. For a nuclear G_{\infty} -space, we prove that a linear map T between normed spaces is 2-quasi-\lambda -nuclear if and only if it is quasi-\lambda -nuclear


Common Fixed Point Theorems For Fuzzy Mappings In Quasi-Pseudo-Metric Spaces, İlker Şahi̇n, Hakan Karayilan, Mustafa Telci̇ Jan 2005

Common Fixed Point Theorems For Fuzzy Mappings In Quasi-Pseudo-Metric Spaces, İlker Şahi̇n, Hakan Karayilan, Mustafa Telci̇

Turkish Journal of Mathematics

In this paper, we obtain some common fixed point theorems for pairs of fuzzy mappings in left K-sequentially complete quasi-pseudo-metric spaces and right K-sequentially complete quasi-pseudo-metric spaces, respectively. Well-known theorems are special cases of our results.


On The Value Set Of N! Modulo A Prime, William D. Banks, Florian Luca, Igor E. Shparlinski, Henning Stichtenoth Jan 2005

On The Value Set Of N! Modulo A Prime, William D. Banks, Florian Luca, Igor E. Shparlinski, Henning Stichtenoth

Turkish Journal of Mathematics

We show that for infinitely many prime numbers p there are at least \log\log p / \log\log\log p distinct residue classes modulo p that are not congruent to n! for any integer n.


An Exponential Model For Treatment Effects Without A Control Group, Kemal Gürsoy Jan 2005

An Exponential Model For Treatment Effects Without A Control Group, Kemal Gürsoy

Turkish Journal of Mathematics

It may be desirable to estimate the behaviour of a pair of random variables and their functions through the information acquired by utilizing only one of them and its functions. In this work, such an approach has been used. Motivated by the need to provide treatment to every patient in a new drug trial, an exponential model was considered. This approach provides sufficient information to make inferences about the effect of a treatment without using a control group who will be otherwise denied treatment, as an alternative method to the commonly used controlled clinical trials.


On Intuitionistic Fuzzy Bi-Ideals Of Semigroups, Kyung Ho Kim, Jong Geol Lee Jan 2005

On Intuitionistic Fuzzy Bi-Ideals Of Semigroups, Kyung Ho Kim, Jong Geol Lee

Turkish Journal of Mathematics

We consider the intuitionistic fuzzification of the concept of several ideals in a semigroup S, and investigate some properties of such ideals.


Constructing New K3 Surfaces, Selma Altinok Jan 2005

Constructing New K3 Surfaces, Selma Altinok

Turkish Journal of Mathematics

This paper is concerned with a method based on birational geometry and produces dozens of new examples in codimensions 3, 4, 5 etc. The method is called unprojection by Reid. Using this method we construct new examples of K3 surfaces of codimensions 3 and 4 in weighted projective spaces from smaller codimension K3 surfaces whose rings are much simpler. This leads to the existence of almost all candidates for codimension 3 K3 surfaces in the list.


On Jordan Generalized Higher Derivations In Rings, Wagner Cortes, Claus Haetinger Jan 2005

On Jordan Generalized Higher Derivations In Rings, Wagner Cortes, Claus Haetinger

Turkish Journal of Mathematics

I. N. Herstein proved that any Jordan derivation on a prime ring of characteristic not 2 is a derivation. M. Breşar extended this result to semiprime rings, while M. Ferrero and C. Haetinger extended the result to Jordan higher derivations. Recently, M. Ashraf and N. Rehman considered the question of Herstein for a Jordan generalized derivation. This paper extends Ashraf's Theorem. We prove that if R is a 2-torsion-free ring which has a commutator right nonzero divisor, then every Jordan generalized higher derivation on R is a generalized higher derivation.


On Fuzzy Cosets Of Gamma Nearrings, Satyanarayana Bhavanari, Syam Prasad Kuncham Jan 2005

On Fuzzy Cosets Of Gamma Nearrings, Satyanarayana Bhavanari, Syam Prasad Kuncham

Turkish Journal of Mathematics

In this paper, we consider fuzzy notion of a \Gamma -near ring, introduce the notion of a fuzzy coset and obtained some related important fundamental isomorphism theorems.


On \Delta-I-Continuous Functions, Şazi̇ye Yüksel, A. Açikgöz, T. Noiri Jan 2005

On \Delta-I-Continuous Functions, Şazi̇ye Yüksel, A. Açikgöz, T. Noiri

Turkish Journal of Mathematics

In this paper, we introduce a new class of functions called \delta-I-continuous functions. We obtain several characterizations and some of their properties. Also, we investigate its relationship with other types of functions.


Spacelike Normal Curves In Minkowski Space E^3_1, Kazim İlarslan Jan 2005

Spacelike Normal Curves In Minkowski Space E^3_1, Kazim İlarslan

Turkish Journal of Mathematics

In the Euclidean space E^3, it is well known that normal curves, i.e., curves with position vector always lying in their normal plane, are spherical curves [3]. Necessary and sufficient conditions for a curve to be a spherical curve in Euclidean 3-space are given in [10] and [11]. In this paper, we give some characterizations of spacelike normals curves with spacelike, timelike or null principal normal in the Minkowski 3-space E^3_1.