WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653

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Citation - WoS: 5
Citation - Scopus: 14
A branch and bound algorithm for sector allocation of a naval task group
(Wiley-blackwell, 2011) Karasakal, Orhan; Kandiller, Levent; Ozdemirel, Nur Evin; 5706; 2634; Endüstri Mühendisliği
A naval task group (TG) is a collection of naval combatants and auxiliaries that are grouped together for the accomplishment of one or more missions. Ships forming a TG are located in predefined sectors. We define determination of ship sector locations to provide a robust air defense formation as the sector allocation problem (SAP). A robust formation is one that is very effective against a variety of attack scenarios but not necessarily the most effective against any scenario. We propose a 0-1 integer linear programming formulation for SAP. The model takes the size and the direction of threat into account as well as the defensive weapons of the naval TG. We develop tight lower and upper bounds by incorporating some valid inequalities and use a branch and bound algorithm to exactly solve SAP. We report computational results that demonstrate the effectiveness of the proposed solution approach. (C) 2011 Wiley Periodicals, Inc. Naval Research Logistics 58: 655-669, 2011
Citation - WoS: 3
Citation - Scopus: 3
A Comparative Study of Effects of Additive Particle Size and Content on Wetting Behavior and Brazing Performance of C/SiC Composite
(Springer, 2023) Saltik, Simge; Esen, Ziya; Dericioglu, Arcan F.; 52373; Ortak Dersler Bölümü
This study has focused on the influence of size and content of SiC particle incorporation on the wetting behavior of the Ticusil brazing filler alloy and on its brazing performance in C/SiC composite/Ti6Al4V alloy joints. The effect of the size and content of additive SiC particles on the variation of molten brazing filler alloy contact angle was recorded at various brazing time and temperatures. Moreover, the microstructural evolution and mechanical properties of the additive containing C/SiC composite/Ti6Al4V alloy joints produced by the brazing method were investigated. The contact angles in both brazing filler alloys containing nano- and micro-sized SiC particles exhibited a sudden decrease with time during isothermal holding as observed in as-received brazing filler alloys. As the quantity of the SiC particles increased in the brazing alloy, the recorded contact angle values including the final, stable contact angle increased, while the time for the drastic contact angle change also increased remarkably. Compared to as-received counterparts, the addition of 2 wt.% nano-sized SiC and 1 wt.% micro-sized SiC particles improved the shear strength of the joints by 35 and 8%, respectively. Although the recorded contact angle values were close to each other in brazing alloys containing SiC particles with different sizes (37 and 42 degrees for 1 wt.% micro-sized and 2 wt.% nano-sized additions), higher increment was achieved in the mechanical performance of the joints with nano-sized SiC additive due to more homogeneous reinforcement effect of the nanoparticles. The results indicated that the optimum brazing filler alloy contact angle for the highest shear strength is similar to 40 degrees for both nano- and micron-sized additive containing Ticusil filler alloy.
Citation - WoS: 13
Citation - Scopus: 14
A Comparative Study of Multiple Regression and Machine Learning Techniques for Prediction of Nanofluid Heat Transfer
(Asme, 2022) Kocak, Eyup; Ayli, Ece; Turkoglu, Hasmet; 283455; 265836; 12941; Makine Mühendisliği
The aim of this article is to introduce and discuss prediction power of the multiple regression technique, artificial neural network (ANN), and adaptive neuro-fuzzy interface system (ANFIS) methods for predicting the forced convection heat transfer characteristics of a turbulent nanofluid flow in a pipe. Water and Al2O3 mixture is used as the nanofluid. Utilizing fluent software, numerical computations were performed with volume fraction ranging between 0.3% and 5%, particle diameter ranging between 20 and 140 nm, and Reynolds number ranging between 7000 and 21,000. Based on the computationally obtained results, a correlation is developed for the Nusselt number using the multiple regression method. Also, based on the computational fluid dynamics results, different ANN architectures with different number of neurons in the hidden layers and several training algorithms (Levenberg-Marquardt, Bayesian regularization, scaled conjugate gradient) are tested to find the best ANN architecture. In addition, ANFIS is also used to predict the Nusselt number. In the ANFIS, number of clusters, exponential factor, and membership function (MF) type are optimized. The results obtained from multiple regression correlation, ANN, and ANFIS were compared. According to the obtained results, ANFIS is a powerful tool with a R-2 of 0.9987 for predictions.
Citation - WoS: 7
Citation - Scopus: 7
A Comparison of Radiation Shielding of Stainless Steel With Different Magnetic Properties
(Vinca inst Nuclear Sci, 2014) Calik, Adnan; Akbunar, Sahin; Ucar, Nazim; Yilmaz, Nihat; Karakas, Mustafa Serdar; Akkurt, Iskender; 48915; Malzeme Bilimi ve Mühendisliği
The radiation shielding properties of three different stainless steels have been investigated. For this purpose, linear attenuation coefficients at photon energy levels of 662 keV and 1250 keV have been measured. The obtained results showed that ferritic stainless steel was more capable in stopping the high energy photons than its non-magnetic counterpart.
Citation - WoS: 40
Citation - Scopus: 40
A density functional study of bare and hydrogenated platinum clusters
(Elsevier, 2006) Sebetci, Ali; 20965; İç Mimarlık
We perform density functional theory calculations using Gaussian atomic-orbital methods within the generalized gradient approximation for the exchange and correlation to study the interactions in the bare and hydrogenated platinum clusters. The minimum-energy structures, binding energies, relative stabilities. vibrational frequencies and the highest occupied and lowest unoccupied molecular-orbital gaps of PtnHm (n = 1-5, m = 0-2) clusters are calculated and compared with previously studied pure platinum and hydrogenated platinum clusters. We investigate any magic behavior in hydrogenated platinum clusters and find that Pt4H2 is snore stable than its neighboring sizes. The lowest energy structure of Pt-4 is found to be a distorted tetrahedron and that of Pt-5 found to be a bridge site capped tetrahedron which is a new global minimum for Pt-5 cluster. The successive addition of H atoms to Pt-n clusters leads to an oscillatory change in the magnetic moment of Pt-3-Pt-5 clusters. (c) 2006 Elsevier B.V. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 6
A discussion on a pata type contraction via iterate at a point
(Univ Nis, Fac Sci Math, 2020) Karapinar, Erdal; Fulga, Andreea; Rakocevic, Vladimir; 19184; Matematik
In this paper, we introduce the notion of Pata type contraction at a point in the context of a complete metric space. We observe that such contractions possesses unique fixed point without continuity assumption on the given mapping. Thus, is extended the original results of Pata. We also provide an example to illustrate its validity.
Citation - WoS: 2
Citation - Scopus: 2
A discussion on the coincidence quasi-best proximity points
(Univ Nis, Fac Sci Math, 2021) Fouladi, Farhad; Abkar, Ali; Karapinar, Erdal; 19184; Matematik
In this paper, we first introduce a new class of the pointwise cyclic-noncyclic proximal contraction pairs. Then we consider the coincidence quasi-best proximity point problem for this class. Finally, we study the coincidence quasi-best proximity points of weak cyclic-noncyclic Kannan contraction pairs. We consider an example to indicate the validity of the main result.
Citation - WoS: 6
Citation - Scopus: 9
A finite grid solution for circular plates on elastic foundations
(Korean Society of Civil Engineers-ksce, 2015) Karasin, Halim; Gulkan, Polat; Aktas, Gultekin; 5743
The transmission of vertical or horizontal structural forces to the supporting soil is a challenge to analyze for structures on elastic foundation which represent a complex medium. The two-parameter elastic foundation model that provides a mechanical interaction between the individual spring elements shows a more realistic behavior of the soil reaction than does the single parameter Winkler model. Since the structural behavior of a beam resembles that of a strip in a plate, in this study, the exact stiffness and mass matrices of the beam element on two-parameter elastic foundation is extended to plates. The framework method that replaces a continuous surface by an idealized discrete system can represent a two-dimensional plate. In the light of this situation, circular plates are modeled as an assemblage of individual beam elements interconnected at their neighboring joints in radial and tangential direction. So, a useful tool called finite grid solution as a numerical method developed in this study lead to solve circular plates resting on two parameter elastic foundation problems. Examples for bending of ring, circular and annual plates on elastic foundation are solved to compare with known analytical solutions and other numerical solutions. The comparisons show that the literature and the computed results are compatible.
Citation - WoS: 0
Citation - Scopus: 1
A Fixed Point Theorem and an Application for the Cauchy Problem in the Scale of Banach Spaces
(Univ Nis, Fac Sci Math, 2020) Vo Viet Tri; Karapinar, Erdal; 19184; Matematik
The main aim of this paper is to prove the existence of the fixed point of the sum of two operators in setting of the cone-normed spaces with the values of cone-norm belonging to an ordered locally convex space. We apply this result to prove the existence of global solution of the Cauchy problem with perturbation of the form {x'(t) = f[t, x(t)] + g[t, x(t)], t is an element of[0,infinity), x(0) = x(0)is an element of F-1, in a scale of Banach spaces f(F-s; parallel to center dot parallel to(s)) : s is an element of(0, 1]}.
Citation - WoS: 1
Citation - Scopus: 2
A fixed point theorem for a system of Pachpatte operator equations
(Springer Basel Ag, 2021) Karapinar, Erdal; Ozturk, Ali; Rakocevic, Vladimir; 19184; Matematik
In this paper, we investigate sufficient conditions for the existence of solutions to the system {Tx=x, alpha(i)(x)=0(E), i = 1,2, ... r, where 0(E) is the zero vector of E, and alpha(i) : E -> E i = 1, 2, ... , r are mappings, T is a mapping satisfying the Pachpatte-contraction.
Citation - WoS: 4
Citation - Scopus: 2
A fixed point theorem for Proinov mappings with a contractive iterate
(Zhejiang Univ Press, 2023) Karapinar, Erdal; Fulga, Andreea; 19184; Çankaya Üniversitesi, Fen - Edebiyat Fakültesi, Matematik Bölümü; Matematik
In this paper, we consider the fixed point theorem for Proinov mappings with a contractive iterate at a point. In other words, we combine and unify the basic approaches of Proinov and Sehgal in the framework of the complete metric spaces. We consider examples to illustrate the validity of the obtained result.
Citation - WoS: 4
Citation - Scopus: 4
A Fourth Order Finite Difference Method for Time-Space Fractional Diffusion Equations
(Global Science Press, 2018) Arshad, Sadia; Baleanu, Dumitru; Huang, Jianfei; Tang, Yifa; Zhao, Yue; 56389; Matematik
A finite difference method for a class of time-space fractional diffusion equations is considered. The trapezoidal formula and a fourth-order fractional compact difference scheme are, respectively, used in temporal and spatial discretisations and the method stability is studied. Theoretical estimates of the convergence in the L-2 -norm are shown to be O(tau(2) + h(4)), where tau and h are time and space mesh sizes. Numerical examples confirm theoretical results.
Citation - WoS: 66
Citation - Scopus: 77
A fractional schrödinger equation and its solution
(Springer/plenum Publishers, 2010) Muslih, Sami I.; Agrawal, Om P.; Baleanu, Dumitru; Matematik
This paper presents a fractional Schrodinger equation and its solution. The fractional Schrodinger equation may be obtained using a fractional variational principle and a fractional Klein-Gordon equation; both methods are considered here. We extend the variational formulations for fractional discrete systems to fractional field systems defined in terms of Caputo derivatives to obtain the fractional Euler-Lagrange equations of motion. We present the Lagrangian for the fractional Schrodinger equation of order alpha. We also use a fractional Klein-Gordon equation to obtain the fractional Schrodinger equation which is the same as that obtained using the fractional variational principle. As an example, we consider the eigensolutions of a particle in an infinite potential well. The solutions are obtained in terms of the sines of the Mittag-Leffler function.
Citation - WoS: 3
Citation - Scopus: 3
A hybrid Maliuzhinets/PO method for diffraction problems by impedance wedges
(Elsevier Science Bv, 2011) Umul, Yusuf Ziya; 42699; Elektronik ve Haberleşme Mühendisliği
The solution of Maliuzhinets of the diffraction problem of waves by an impedance wedge is transformed into a physical optics integral. The resultant expression is suitable for the investigation of various diffraction problems having impedance wedges. The method is applied to the scattering of waves by an impedance spherical reflector with wedge structure at its discontinuity. The results are examined numerically. (C) 2011 Elsevier B.V. All rights reserved.
Citation - WoS: 36
A lie group approach to solve the fractional poisson equation
(Editura Acad Romane, 2015) Hashemi, M. S.; Baleanu, D.; Parto-Haghighi, M.; Matematik
In the present paper, approximate solutions of fractional Poisson equation (FPE) have been considered using an integrator in the class of Lie groups, namely, the fictitious time integration method (FTIM). Based on the FTIM, the unknown dependent variable u(x, t) is transformed into a new variable with one more dimension. We use a fictitious time tau as the additional dimension (fictitious dimension), by transformation: v(x, t, tau) := (1 + tau)(k) u(x, t), where 0 < k <= 1 is a parameter to control the rate of convergency in the FTIM. Then the group preserving scheme (GPS) is used to integrate the new fractional partial differential equations in the augmented space R2+1. The power and the validity of the method are demonstrated using two examples.
Citation - WoS: 4
Citation - Scopus: 5
A Mechanical Model Based on Conformal Strain Energy and Its Application to Bending and Buckling of Nanobeam Structures
(Asme, 2019) Rahimi, Zaher; Sumelka, Wojciech; Baleanu, Dumitru; 56389; Matematik
In the present work, a nonlocal model based on the conformal strain energy, utilizing the conformable derivative definition, has been obtained. The model has two additional free parameters compared to the classical (local) mechanical formulations. The first one specifies the amount of the integer and the noninteger gradient of strain in the strain energy relation, and the second one controls the order of the strain derivatives in the conformable energy relation. The obtained governing (nonlinear) equation has been solved by the Galerkin method and the effects of both free parameters have been shown. As a case study, the bending and buckling of nanobeam structures has been studied.
Citation - WoS: 107
Citation - Scopus: 118
A New Analysis of Fractional Fish Farm Model Associated With Mittag-Leffler-Type Kernel
(World Scientific Publ Co Pte Ltd, 2020) Singh, Jagdev; Kumar, Devendra; Baleanu, Dumitru; 56389; Matematik
In this paper, we analyze the dynamical behavior of fish farm model related to Atangana-Baleanu derivative of arbitrary order. The model is constituted with the group of non-linear differential equations having nutrients, fish and mussel. We have included discrete kind gestational delay of fish. The solution of fish farm model is determined by employing homotopy analysis transforms method (HATM). Existence of and uniqueness of solution are studied through Picard-Lindelof approach. The influence of order of new non-integer order derivative on nutrients, fish and mussel is discussed. The complete study reveals that the outer food supplies manage the behavior of the model. Moreover, to show the outcomes of the study, some numerical results are demonstrated through graphs.
Citation - WoS: 35
Citation - Scopus: 37
A New Application of the Fractional Logistic Map
(Editura Acad Romane, 2016) Huang, Lan-Lan; Baleanu, Dumitru; Wu, Guo-Cheng; Zeng, Sheng-Da; 56389; Matematik
The fractional chaotic map started to be applied in physics and engineering to properly treat some real-world phenomena. A shuffling method is proposed based on the fractional logistic map. The fractional difference order is used as a key. An image encryption scheme is designed by using the XOR operation and the security analysis is given. The obtained results demonstrate that the fractional difference order makes the encryption scheme highly secure.
Citation - WoS: 1
Citation - Scopus: 2
A new causal discovery heuristic
(Springer, 2018) Prestwich, S. D.; Tarim, S. A.; Ozkan, I.; 6641; 169580; Yönetim Bilişim Sistemleri
Probabilistic methods for causal discovery are based on the detection of patterns of correlation between variables. They are based on statistical theory and have revolutionised the study of causality. However, when correlation itself is unreliable, so are probabilistic methods: unusual data can lead to spurious causal links, while nonmonotonic functional relationships between variables can prevent the detection of causal links. We describe a new heuristic method for inferring causality between two continuous variables, based on randomness and unimodality tests and making few assumptions about the data. We evaluate the method against probabilistic and additive noise algorithms on real and artificial datasets, and show that it performs competitively.
Citation - WoS: 5
A new existence results on fractional differential inclusions with state-dependent delay and Mittag-Leffler kernel in Banach space
(Ovidius Univ Press, 2022) Arjunan, Mani Mallika; Kavitha, Velusamy; Baleanu, Dumitru; 56389; Matematik
In this manuscript the existence of the fractional-order functional differential inclusions [FFDI] with state-dependent delay [SDD] is investigated within the Mittag-Leffler kernel. We use both contractive and condensing maps to prove the existence of mild solutions through solution operator. Finally, an example is presented to illustrate the theoretical findings.

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