Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Turkey (129)
- 1 (99)
- 2 (83)
- Classification (75)
- Deep learning (75)
-
- Machine learning (72)
- Optimization (69)
- Genetic algorithm (62)
- Synthesis (62)
- Adsorption (58)
- Geochemistry (55)
- Particle swarm optimization (53)
- Antimicrobial activity (47)
- 3 (45)
- Artificial neural network (42)
- Stability (40)
- Support vector machine (37)
- Phthalocyanine (36)
- Antibacterial activity (35)
- Feature extraction (33)
- Artificial neural networks (32)
- Feature selection (31)
- Wireless sensor networks (31)
- Molecular docking (30)
- Cytotoxicity (29)
- Copper (28)
- DFT (28)
- Oscillation (28)
- Power quality (28)
- COVID-19 (27)
- Publication Year
Articles 10111 - 10140 of 12093
Full-Text Articles in Entire DC Network
Mining Classification Rules By Using Genetic Algorithms With Non-Random Initial Population And Uniform Operator, Korkut Koray Gündoğan, Bi̇lal Alataş, Ali̇ Karci
Mining Classification Rules By Using Genetic Algorithms With Non-Random Initial Population And Uniform Operator, Korkut Koray Gündoğan, Bi̇lal Alataş, Ali̇ Karci
Turkish Journal of Electrical Engineering and Computer Sciences
Classification is a supervised learning method that induces a classification model from a database and is one of the most commonly applied data mining task. The frequently employed techniques are decision tree or neural network-based classification algorithms. This work presents an efficient genetic algorithm (GA) for classification rule mining technique that discovers comprehensible IF-THEN rules using a generalized uniform population method and a uniform operator inspired from the uniform population method. Initial population is generated by methodically eliminating the randomness by generalized uniform population method. In the subsequence generations, genetic diversity is ensured and premature convergence is prevented by the …
A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem
A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem
Turkish Journal of Electrical Engineering and Computer Sciences
Differential Evolution (DE) algorithm is a new heuristic approach mainly having three advantages; finding the true global minimum regardless of the initial parameter values, fast convergence, and using few control parameters. DE algorithm is a population based algorithm like genetic algorithms using similar operators; crossover, mutation and selection. In this work, we have compared the performance of DE algorithm to that of some other well known versions of genetic algorithms: PGA, Grefensstette, Eshelman. In simulation studies, De Jong's test functions have been used. From the simulation results, it was observed that the convergence speed of DE is significantly better than …
The 7 C'S For Creating Living Software: A Research Perspective For Quality-Oriented Software Engineering, Mehmet Akşi̇t
The 7 C'S For Creating Living Software: A Research Perspective For Quality-Oriented Software Engineering, Mehmet Akşi̇t
Turkish Journal of Electrical Engineering and Computer Sciences
This article proposes the 7 C's for realizing quality-oriented software engineering practices. All the desired qualities of this approach are expressed in short by the term living software. The 7 C's are: Concern-oriented processes, Canonical models, Composable models, Certifiable models, Constructible models, Closure property of models and Controllable models. Each C is explained by the help of a set of definitions, a short overview of the background work and the problems that software engineers may experience in realizing the corresponding C. Further, throughout the article, a software development example is presented for illustrating the realization of the 7 C's. Finally, …
A Platform For Software Engineering Course Projects, Bi̇rol Aygün
A Platform For Software Engineering Course Projects, Bi̇rol Aygün
Turkish Journal of Electrical Engineering and Computer Sciences
The importance of projects in software engineering courses is well known. Both synthetic and real-life projects have various advantages and disadvantages. Our aim was to create a framework where students can develop projects which reflect some of the complexities of real-life, involving many concurrent, interacting, asynchronous processes, each in a different stage of development, with wide temporal differences among them - some occurring within millisconds of each other and others executing sporadically over much longer periods. In this project, which was carried out in different arrangements in several software engineering courses in three universities, the students developed both the sub- …
A Pattern Based Approach To Web Design Formalization, Ahmet Sikici, Yasemi̇n Topaloğlu
A Pattern Based Approach To Web Design Formalization, Ahmet Sikici, Yasemi̇n Topaloğlu
Turkish Journal of Electrical Engineering and Computer Sciences
World Wide Web is a global information network that affects many fields of our lives. The distributed, interlinked, visual and heterogeneous structure of the web makes it an irregular development environment. In this paper we propose a pattern based approach for increasing the effectiveness of development for the Web environment. This approach is based on the representation of the core meaning of each design as a set of patterns and requires the formulation of abstract solutions in a mathematical precision. This way not only reusable design experience will be codified unambiguously, but a smooth transition between the design and implementation …
An Agile Information Systems Development Method In Use, Mehmet Nafi̇z Aydin, Frank Harmsen, Kees Van Slooten, Robert Stegwee
An Agile Information Systems Development Method In Use, Mehmet Nafi̇z Aydin, Frank Harmsen, Kees Van Slooten, Robert Stegwee
Turkish Journal of Electrical Engineering and Computer Sciences
Recently, agile information systems development methods, agile methods in short, have got considerable attention from practitioners. One of the reasons seems that agile methods, to some degree, can be adaptable to different project situations. However, little empirical research has been conducted on this subject. The major goal of this research is to identify which aspects of agile methods are perceived as most critical and difficult to realize and how such aspects are adapted in practice. To reach this goal we studied the working practices concerning the adaptation of an agile method in the IT department of one of the leading …
Cover And Contents
Turkish Journal of Electrical Engineering and Computer Sciences
No abstract provided.
A Robustness Analysis Of Game-Theoretic Cdma Power Control, Xingzhe Fan, Murat Arcak, John T. Wen
A Robustness Analysis Of Game-Theoretic Cdma Power Control, Xingzhe Fan, Murat Arcak, John T. Wen
Turkish Journal of Electrical Engineering and Computer Sciences
This paper studies robustness of a gradient-type CDMA uplink power control algorithm with respect to disturbances and time-delays. This problem is of practical importance because unmodeled secondary interference effects from neighboring cells play the role of disturbances, and propagation delays are ubiquitous in wireless data networks. We first show L_p-stability, for p \in [1,\infity], with respect to additive disturbances. We pursue L_{\infity}-stability within the input-to-state stability (ISS) framework of Sontag [7], which makes explicit the vanishing effect of the initial conditions. Next, using the ISS property and a loop transformation, we prove that global asymptotic stability is preserved for sufficiently …
Global Stability Analysis Of An End-To-End Congestion Control Scheme For General Topology Networks With Delay, Tansu Alpcan, Tamer Başar
Global Stability Analysis Of An End-To-End Congestion Control Scheme For General Topology Networks With Delay, Tansu Alpcan, Tamer Başar
Turkish Journal of Electrical Engineering and Computer Sciences
We analyze the stability properties of an end-to-end congestion control scheme under fixed heterogeneous delays, and for general network topologies. The scheme analyzed is based on the congestion control game of [1], with the starting point being the unique Nash equilibrium of that game. We prove global stability of this solution (and hence of the congestion control algorithm) under a mild symmetricity condition. We further demonstrate the stability of the algorithm numerically for various delays, user numbers, and topologies
Flow Controller Design And Performance Analysis For Self-Similar Network Traffic, Peng Yan
Flow Controller Design And Performance Analysis For Self-Similar Network Traffic, Peng Yan
Turkish Journal of Electrical Engineering and Computer Sciences
Recent studies of high-resolution traffic measurement discovered the self-similarity in both LAN and WAN traffic. In this paper, we introduce a two-degree of freedom rate based flow controller, which includes a robust H^{\infity} control block and an LMMSE based capacity predictor. The former part can guarantee the robust stability against time-varying time delay uncertainties and the latter improves the transient response by predicting the self-similar cross-traffic. Implementation issues are discussed and performance analysis is provided to validate our design. We also investigate the prediction and control in larger time scale which is more applicable for the real network environment
Optimum And Suboptimum Blind Channel And Symbol Estimation For Siso Channels, T. Engi̇n Tuncer
Optimum And Suboptimum Blind Channel And Symbol Estimation For Siso Channels, T. Engi̇n Tuncer
Turkish Journal of Electrical Engineering and Computer Sciences
We present three methods for blind channel and symbol identification from a single or multi-block observation. These methods are deterministic approaches suitable for the identification of quickly changing wireless channels. The first method uses the finite alphabet property and it has good performance even for noisy observations. It requires only a single data frame, which is a unique feature of the method. This method can also be used to identify the channel order. For multi-block observations, we present the maximal ratio combining cross relation (MRCCR) method. It is an optimum approach in terms of instantaneous SNR and is based on …
Cover And Contents
Turkish Journal of Electrical Engineering and Computer Sciences
No abstract provided.
The Zero Position Of The Forward-Backward Asymmetry In The B \Rightarrow K\Ell^+\Ell^- Decay With New Physics Effects, Altuğ Arda
Turkish Journal of Physics
Using the most general model-independent effective Hamiltonian comprising local four-Fermi operators (scalar, vector, and tensor operators), we study the sensitivity of the zero position of the lepton asymmetry to the new operators beyond the Standard Model (SM) in the B \rightarrow K\ell^+\ell^- decay. It is found that among all operators, only the scalar and tensor operators contribute to the forward-backward asymmetry, in which case the forward-backward asymmetry has a non-vanishing value.
Simulation Of Millimeter-Wave Gunn Oscillations In Gallium Nitride, Cem Sevi̇k, Ceyhun Bulutay
Simulation Of Millimeter-Wave Gunn Oscillations In Gallium Nitride, Cem Sevi̇k, Ceyhun Bulutay
Turkish Journal of Physics
High field transport in wide bandgap semiconductors like GaN is of great technological importance. The negative differential mobility regime at high fields, under suitable conditions, can lead to millimeter-wave Gunn oscillations. Using extensive simulation based an ensemble Monte Carlo technique, the prospects of GaN Gunn diodes are theoretically investigated. The possibility of operating these Gunn diodes at their higher harmonic modes are explored. The main finding of this research is that the carrier dynamics in GaN can be tailored by an optimum choice of doping profile, temperature and bias conditions so that the efficiency of higher harmonic Gunn oscillations can …
On A Certain Class Of Bessel Integrals, Ali A. Al-Jarrah, A. Al-Momani
On A Certain Class Of Bessel Integrals, Ali A. Al-Jarrah, A. Al-Momani
Turkish Journal of Mathematics
There are many old results of integrals involving Bessel functions, currently available in handbooks, but we found no recourse in the well-known references to how they were established. In this paper, we attempt to have a clear way of proving some of these results. In fact, we consider a certain class of Bessel integrals where we prove that such integrals vanish under certain conditions. To this end some theorems regarding this class of integrals with their proofs are put forward. A computer algorithm is provided to implement some of our results. The result in this paper extend the work in …
A Note On Groups With All Subgroups Subnormal, Ahmet Arikan, Tahi̇re Özen
A Note On Groups With All Subgroups Subnormal, Ahmet Arikan, Tahi̇re Özen
Turkish Journal of Mathematics
We prove that if G is a periodic group with all subgroups subnormal, and if for every x, y \in G, ^{G} is an FC-group, then G is nilpotent.
An Information System For Streamlining Software Development Process, Serkan Nalbant
An Information System For Streamlining Software Development Process, Serkan Nalbant
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper an information system to be employed by software development organizations is proposed, which automates software development process. The proposed system aims to lower cost, improve schedule performance and enhance quality of the software projects by the means of automation and unifying of operational information. The characteristics of the proposed system are described. Furthermore, its use is illustrated via the explanation of an exemplary software system called PACE that serves as an information system for planning, controlling, measuring and improving software development process and projects. The relationship of PACE with Software Capability Maturity Model (CMM) is also provided.
Geochemistry And Geochronology Of Orthogneisses In The Derbent (Alaşehir) Area, Eastern Part Of The Ödemiş-Kiraz Submassif, Menderes Massif: Pan-African Magmatic Activity, Ersi̇n Koralay, O. Özcan Dora, Fukun Chen, Muharrem Satir, Osman Candan
Geochemistry And Geochronology Of Orthogneisses In The Derbent (Alaşehir) Area, Eastern Part Of The Ödemiş-Kiraz Submassif, Menderes Massif: Pan-African Magmatic Activity, Ersi̇n Koralay, O. Özcan Dora, Fukun Chen, Muharrem Satir, Osman Candan
Turkish Journal of Earth Sciences
Pan-African basement rocks and the Palaeozoic cover series of the Menderes Massif are exposed around Derbent (Alaşehir) in the eastern part of the Ödemiş-Kiraz submassif. Garnet-mica schists of the Pan-African basement are intruded by the protoliths of orthogneisses and Triassic leucocratic orthogneisses. This study focuses on the geochronology and geochemistry of orthogneisses related to the Pan-African evolution of the Menderes Massif in latest Proterozoic time. Geochemical data suggest that the orthogneisses were derived from S-type, peraluminous, syn- to post-collisional granitoids of calc-alkaline affinity. Zircon grains from the orthogneisses, which are euhedral with typical igneous morphologies, were dated by the Pb-Pb …
Variation Of Chemical Potential Oscillations Of A 2deg In A Quantum Well Under A Magnetic Field For Multiple Sub-Band Occupation As Function Of Temperature And Level-Broadening, Berri̇n Özdemi̇r, Zeki̇ Yarar, Meti̇n Özdemi̇r
Variation Of Chemical Potential Oscillations Of A 2deg In A Quantum Well Under A Magnetic Field For Multiple Sub-Band Occupation As Function Of Temperature And Level-Broadening, Berri̇n Özdemi̇r, Zeki̇ Yarar, Meti̇n Özdemi̇r
Turkish Journal of Physics
We study the variation of chemical potential in a two dimensional electron gas in a uniform magnetic field as a function of temperature and level-broadening parameter. Schrödinger and Poisson equations are solved self-consistently for a two dimensional electron gas formed in a Ga_xAl_{1-x}As/GaAs quantum well, to numerically determine the potential profile, empty or occupied energy sub-bands, the wavefunctions and electron concentrations corresponding to each sub-band at various temperatures. Then assuming that the electron concentration is not altered, the variation of chemical potential with respect to both temperature and energy level-broadening parameter is studied under a uniform and constant magnetic field. …
Effect Of Iron Concentrations On Some Physical Properties Of The System Li_{0.5}Fe_{X}Ga_{2.5 - X}O_{4}, Abd El-Raouf Tawfik, N. Tashtoush, O.M. Hemeda
Effect Of Iron Concentrations On Some Physical Properties Of The System Li_{0.5}Fe_{X}Ga_{2.5 - X}O_{4}, Abd El-Raouf Tawfik, N. Tashtoush, O.M. Hemeda
Turkish Journal of Physics
A series of Li_{0.5} Fe_{x} Ga_{2.5 - x} O_{4} systems were prepared for x = 0, 0.25, 0.5, 0.75 and 1 by the general ceramic method. X-ray diffraction showed that all compositions have single phase Spinel cubic structure. The lattice parameter increased with enhancing iron concentration. The thermoelectric coefficient decreased with increasing x, and the majority carriers are holes. The increase of the jump length of hole increased the electrical conductivity. Jump-length increased with iron concentration and the rate of jumping gave rise to the electrical conductivity. The concentration of Fe^{3 +} ions in Lithium gallate is important, for such …
Amps-1d Modeling Of A-Si:H N^{+}-I-N^{+} Structure: The Validity Of Space Charge Limited Current Analysis, Aynur Eray, G. Nobile
Amps-1d Modeling Of A-Si:H N^{+}-I-N^{+} Structure: The Validity Of Space Charge Limited Current Analysis, Aynur Eray, G. Nobile
Turkish Journal of Physics
In this paper, the AMPS-1D (Analysis of Microelectronic and photonic structure) simulation program is used to understand the origin of the differences observed in Space Charge Limited Current (SCLC) analysis in thin and thick a-Si:H n^{ +} -i- n^{+} structure. For that purpose, the problem of applicability of SCLC measurements to n^{+}-i-n^{+} a-Si:H samples are investigated by using both the thin (0.3 \mu m) and thick (3 \mu m) samples. The simulation results show that activation energy in thick samples is larger than in thinner samples, which are an agreement with the experimental results. It is emphasized that this method …
Dielectric Properties And Conductivity Of Khco_3, Fathy Salman, S. Aboelhssan, Eslam Sheha, Mabrouk Elmansy
Dielectric Properties And Conductivity Of Khco_3, Fathy Salman, S. Aboelhssan, Eslam Sheha, Mabrouk Elmansy
Turkish Journal of Physics
KHCO_{3} compound was characterized in three principle realms: for its dielectric properties as a function of temperature and frequency in the ranges 300--370 K and 50 Hz to 1 MHz, respectively; bulk conductivity as a function of temperature, via impedance technique; and relaxation time as function of temperature. Variations of the bulk conductivity and relaxation time with temperature have been found to yield two segments, with two different activation energies. The activation energy for the two segments due to bulk conductivity have been found as 1.96 eV and 1.85 eV, while the activation energy due to relaxation have been found …
Charged Particle--Image Interaction Near A Conducting Surface, Ersen Mete, Meti̇n Durgut
Charged Particle--Image Interaction Near A Conducting Surface, Ersen Mete, Meti̇n Durgut
Turkish Journal of Physics
The interaction of a bulk electron with conducting surfaces is studied by means of the Bohm-Pines transformation in the second quantization formalism. The effective interaction potentials are obtained for the case of one plane and two plane configurations in the form of electron-image electron scattering.
Solution Of The Schrödinger Equation With One And Two Timensional Double-Well Potentials, Ramazan Koç, Derya Haydargi̇l
Solution Of The Schrödinger Equation With One And Two Timensional Double-Well Potentials, Ramazan Koç, Derya Haydargi̇l
Turkish Journal of Physics
The Schrödinger equation with one and two dimensional potentials are solved in the framework of the sl_2(R) Lie algebra. Eigenfunctions of the Schrödinger equation for various asymmetric double-well potentials have been determined and the eigenstates are expressed in terms of the orthogonal polynomials. The solution of the double-well potential in two dimension have been analyzed.
Electrical Properties Of Hydrogen Transport Vpe Grown N-Cdte Epilayers On Znte/Gaas, Murat Bayhan
Electrical Properties Of Hydrogen Transport Vpe Grown N-Cdte Epilayers On Znte/Gaas, Murat Bayhan
Turkish Journal of Physics
Electrical characterisation of n-CdTe epilayers grown by hydrogen transport vapour phase epitaxy (H_2T-VPE) on insulating ZnTe/(100)GaAs substrates through the temperature dependent Hall measurements is reported. Double-crystal X-ray diffraction assessments indicate the material high crystalline quality. Samples grown at temperatures, T_G < 650 °C were p-type, but appeared to be n-type for the temperatures above T_G > 650 °C. Hall measurements performed on n-type samples of different thicknesses grown at T_G = 764 °C showed room temperature carrier densities in the range of 10^{11}-10^{14} cm^{-3}. The electron density and Hall mobility characteristics may be in principle well explained with a two-level affective model. The model of scattering by lattice and ionised impurity were found to be limiting …
Structural Characterization And Magnetization Of Mg_{0.5}Cu_{0.5}Y_{X}Fe_{2-X}O_4 Ferrites, Mansour Al-Haj
Structural Characterization And Magnetization Of Mg_{0.5}Cu_{0.5}Y_{X}Fe_{2-X}O_4 Ferrites, Mansour Al-Haj
Turkish Journal of Physics
Mg_{0.5}Cu_{0.5}Y_xFe_{2-x}O_4 ferrites were prepared by the solid state reaction method and were characterized by X-ray diffraction and magnetization measurements. A single spinel phase was obtained in the range 0 \le x \le 0.08. The lattice parameter was found to increase with the increase of x except at x = 0.08, which may indicate a distortion in the spinel lattice. The saturation magnetization was found to decrease with increasing x due to replacement of the magnetic Fe^{3+} ions by the nonmagnetic Y^{3+} ions.