WoS İndeksli Yayınlar Koleksiyonu

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

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Now showing 1 - 20 of 2070

Citation - WoS: 20
Citation - Scopus: 24
The (2+1)-Dimensional Hyperbolic Nonlinear Schrodinger Equation and Its Optical Solitons
(Amer inst Mathematical Sciences-aims, 2021) Hosseini, Kamyar; Salahshour, Soheil; Sadri, Khadijeh; Mirzazadeh, Mohammad; Park, Choonkil; Ahmadian, Ali; Baleanu, Umitru; Baleanu, Dumitru
A comprehensive study on the (2+1)-dimensional hyperbolic nonlinear Schrodinger (2D-HNLS) equation describing the propagation of electromagnetic fields in self-focusing and normally dispersive planar wave guides in optics is conducted in the current paper. To this end, after reducing the 2D-HNLS equation to a one-dimensional nonlinear ordinary differential (1D-NLOD) equation in the real regime using a traveling wave transformation, its optical solitons are formally obtained through a group of well-established methods such as the exponential and Kudryashov methods. Some graphical representations regarding optical solitons that are categorized as bright and dark solitons are considered to clarify the dynamics of the obtained solutions. It is noted that some of optical solitons retrieved in the current study are new and have been not retrieved previously.
A 6-Point Subdivision Scheme and Its Applications for the Solution of 2nd Order Nonlinear Singularly Perturbed Boundary Value Problems
(Amer inst Mathematical Sciences-aims, 2020) Baleanu, Dumitru; Ejaz, Syeda Tehmina; Anju, Kaweeta; Ahmadian, Ali; Salahshour, Soheil; Ferrara, Massimiliano; Mustafa, Ghulam; Anjum, Kaweeta
In this paper, we first present a 6-point binary interpolating subdivision scheme (BISS) which produces a C-2 continuous curve and 4th order of approximation. Then as an application of the scheme, we develop an iterative algorithm for the solution of 2nd order nonlinear singularly perturbed boundary value problems (NSPBVP). The convergence of an iterative algorithm has also been presented. The 2nd order NSPBVP arising from combustion, chemical reactor theory, nuclear engineering, control theory, elasticity, and fluid mechanics can be solved by an iterative algorithm with 4th order of approximation.
A First-Order System of Equations on a Compact Star Graph
(Ankara Univ, FAC Sci, 2025) Mutlu, Gokhan; Ugulu, Ekin
This study concerns a boundary value problem generated by a system of first-order differential equations and some symmetric boundary conditions on a compact star graph. Unlike usual quantum graph Hamiltonians, the Hamiltonian considered in this paper acts on vector-valued functions living on the edges. Appropriate vertex conditions are introduced to ensure the corresponding boundary value problem is symmetric. In particular, coupling and separated conditions are imposed at the central and boundary vertices, respectively. Moreover, the general form of the vertex conditions at the central vertex is discussed. Finally, the characteristic function is constructed for the symmetric boundary value problem generated by the first-order system and specific coupling vertex conditions.
A Housing Satisfaction Study in an Area of Urban Transformation: The Case of the Turk-Is Apartment Blocks
(Yildiz Technical Univ, FAC Architecture, 2017) Kahraman, Zerrin Ezgi; Ozdemir, Suna Senem
This study investigated the housing satisfaction and the urban transformation expectations in the Turk-is Blocks, built by a labor cooperative in the Altinpark neighborhood of Altindag, Ankara. The area was declared risky in 2013. A survey and in-depth interviews were conducted to examine the satisfaction of residents with housing and their expectations of urban transformation. The results revealed that a large number of the respondents were satisfied with their houses and living environment. Satisfaction increased with duration of time living in the area and age. Over time, the homogenous and stable population in the area has reorganized their houses according to their needs and established a spatial, social, and emotional connection to their neighborhood. The strengths of the area include its neighborhood identity, close social relations, accessibility, and sufficiency of urban services and green areas. Areas of dissatisfaction included insufficient indoor installations, cultural/sports facilities, and security and parking lot problems. Most residents did not support urban transformation plans; however, those who do support the idea have high expectations of the process. With the condition of maintaining their current spatial rights, many perceived urban transformation as a solution to the problems of the area and indicated that their economic status has improved and that life has become more luxurious and comfortable.
A k-Dimensional System of Fractional Finite Difference Equations
(Hindawi Ltd, 2014) Baleanu, Dumitru; Rezapour, Shahram; Salehi, Saeid
We investigate the existence of solutions for a k-dimensional system of fractional finite difference equations by using the Kranoselskii's fixed point theorem. We present an example in order to illustrate our results.
A New Impulsive Multi-Orders Fractional Differential Equation Involving Multipoint Fractional Integral Boundary Conditions
(Hindawi LTD, 2014) Wang, Guotao; Liu, Sanyang; Zhang, Lihong; Baleanu, Dumitru
A new impulsive multi-orders fractional differential equation is studied. The existence and uniqueness results are obtained for a nonlinear problem with fractional integral boundary conditions by applying standard fixed point theorems. An example for the illustration of the main result is presented.
Citation - WoS: 5
Citation - Scopus: 6
A Review of Passive Design Strategies and Their Effect on Thermal Resilience in Low-Income Households
(Elsevier Science S.A., 2025) Kokatnur, Tejas; Ferreira, Shane; Akkoc, Busra Karadeniz; Markarian, Elin; Nojedehi, Pedram; Qiblawi, Seif; Azar, Elie
Climate change is causing more frequent and extreme weather events (e.g., heat waves and ice storms) that disproportionately impact low-income households with poor building conditions. Passive design strategies offer a promising solution to enhance building thermal resilience; however, little is known about their actual application and effectiveness in low-income households under different climate conditions. This paper presents a scoping literature review of 123 articles that evaluated passive design strategies applied to low-income housing contexts. The detailed article review shows that wall-and roof-related passive design strategies (e.g., insulation, sealing) are the most frequently studied and effective strategies, increasing comfort hours and energy savings with a wide variation of up to 24 % and 67 %, respectively. Combined strategies often outperformed individual strategies. In contrast, some studies reported unintended consequences following the adoption of passive design strategies, such as increases in energy demand reaching as high as 50 %. Such findings shed light on the need for design processes to consider multiple performance metrics, as well as behavioural and socio-economic factors that require more in-depth investigation, such as energy poverty and rebound effects. Detailed recommendations are finally provided to guide future research and applications on the topic, covering the need to (i) explore and combine underrepresented thermal resilience strategies and metrics, (ii) follow more standardized reporting practices, (iii) quantify costs and identify implementation barriers, and (iv) integrate participatory research methods to support technical assessments with contextual knowledge of the studied low-income households and communities.
A Sequential Coding Approach for Short Length LT Codes over A WGN Channel
(IEEE, 2017) Abdulkhaleq, Nadhir Ibrahim; Gazi, Orhan
Luby Transform (LT) codes which can be considered as one of the first type of rate less codes are introduced to be an efficient erasure code. In such codes a fountain of encoded symbols is continuously transmitted until the successfully delivery of all the data packets. Whenever the receiver collects N noisy encoded symbols the decoding operation starts. Usually belief propagation (BP) algorithm is used to decipher the code and extract the k data symbols. In this paper, short length LT codes are generated using efficient sequential encoding approach (SEA) and performance measurements have been done over additive white Gaussian (A WGN) channel. This coding technique generates its degree in a repeated sequential manner which yields a mutual relation between adjacent codes that will be used in the decoding part. The decoding complexity of the proposed structure is similar to that of the Raptor codes. The simulation results show that the proposed approach has better performance in terms of error floor and successful decoding ratio when compared to LT codes using robust soliton distribution (RSD) and memorybased-RSD (MBRSD) even when supported by belief propagation-pattern recognition (BP-PR) technique.
A Soft Sensor-Integrated Cell Stretching Device for Precise and Reproducible Mechanotransduction
(Royal Soc, 2026) Yildiz, Solen Kumbay; Akar, Samet; Ozturk, Emre; Dincer, Pervin; Uyanik, Ismail; Duz, Nilufer
Mechanical stretch is a fundamental regulator of cell fate, yet in vitro replication remains challenging because conventional stretchers deliver non-uniform strain and ignore batch-to-batch variations in substrate stiffness-so the stress actually experienced by cells varies unpredictably. We introduce the first biaxial cell-stretching platform that couples an embedded soft resistive micro-channel sensor with high-frequency closed-loop control. Real-time deformation read-out (60 Hz) drives a 24 kHz actuator loop to compensate for polydimethylsiloxane (PDMS) moduli spanning an order of magnitude, delivering user-defined triangular or square waveforms (5-20% amplitude; 0.5-10 s period) with less than 2% steady-state error. Closed-loop operation maintains strain-invariant membrane stress within +/- 5%, reducing well-to-well variability threefold compared with open-loop actuation. Biological validation using immortalized human myoblasts exposed to 10% cyclic stretch for 4 h produced a significant upregulation of YAP/TAZ target genes (C-MYC, MYL9, DIAPH1, ANKRD1; p < 0.001), confirming mechanotransductive efficacy. The platform's modular architecture accommodates stiffness-tunable hydrogels and live imaging, offering a reproducible tool for mechanobiology, tissue engineering, disease modelling and personalized mechanotherapy.
A Switching Inverse Dynamics Controller for Parallel Manipulators around Drive Singular Configurations
(Tubitak Scientific & Technological Research Council Turkey, 2016) Ider, Sitki Kemal; Ozdemir, Mustafa
Despite many advantages, parallel manipulators are known to possess drive singularities where the control of one or more degrees of freedom is lost. Around these singular configurations, the required actuator forces grow unbounded. Previous efforts in the literature put forward singularity-consistent trajectory planning and singularity robust modification of the dynamic equations as a solution to this problem. However, this previous method is applicable only for the open-loop operation of the manipulator, whereas initial configuration errors, external disturbances, and modeling errors should necessarily be taken into account in a closed-loop sense in real-life applications. With this aim, a switching inverse dynamics controller is proposed in this study for the trajectory tracking control of parallel manipulators as they pass through drive singular configurations. Simulations of the application of the developed controller result in good tracking performance, even in the presence of modeling errors, while the actuator efforts remain bounded and continuous in the neighborhood of the singularity.
Citation - WoS: 5
Citation - Scopus: 7
About Fractional Calculus of Singular Lagrangians
(Fuji Technology Press Ltd, 2005) Baleanu, Dumitru
In this paper the solutions of the fractional Euler-Lagrange equations corresponding to singular fractional Lagrangians were examined. We observed that if a Lagrangian is singular in the classical sense, it remains singular after being fractionally generalized. The fractional Lagrangian is non-local but its gauge symmetry was preserved despite complexity of equations in fractional cases. We generalized four examples of singular Lagrangians admitting gauge symmetry in fractional case and found solutions to corresponding Euler-Lagrange equations.
Citation - WoS: 19
Citation - Scopus: 21
About Maxwell's Equations on Fractal Subsets of R³
(de Gruyter Poland Sp Z O O, 2013) Golmankhaneh, Ali K.; Baleanu, Dumitru; Golmankhaneh, Alireza K.
In this paper we have generalized -calculus for fractals embedding in a"e(3). -calculus is a fractional local derivative on fractals. It is an algorithm which may be used for computer programs and is more applicable than using measure theory. In this Calculus staircase functions for fractals has important role. -fractional differential form is introduced such that it can help us to derive the physical equation. Furthermore, using the -fractional differential form of Maxwell's equations on fractals has been suggested.
Citation - WoS: 3
Citation - Scopus: 6
About the Existence Results of Fractional Neutral Integrodifferential Inclusions With State-Dependent Delay in Frechet Spaces
(Hindawi Ltd, 2016) Baleanu, Dumitru; Selvarasu, Siva; Arjunan, Mani Mallika; Suganya, Selvaraj
A recent nonlinear alternative for multivalued contractions in Frechet spaces thanks to Frigon fixed point theorem consolidated with semigroup theory is utilized to examine the existence results for fractional neutral integrodifferential inclusions (FNIDI) with state-dependent delay (SDD). An example is described to represent the hypothesis.
Citation - WoS: 1
Citation - Scopus: 2
Absolutely Stable Difference Scheme for a General Class of Singular Perturbation Problems
(Springer, 2020) Alotaibi, A. M.; Ebaid, Abdelhalim; Baleanu, Dumitru; Machado, Jose Tenreiro; Hamed, Y. S.; El-Zahar, Essam R.; Tenreiro Machado, José
This paper presents an absolutely stable noniterative difference scheme for solving a general class of singular perturbation problems having left, right, internal, or twin boundary layers. The original two-point second-order singular perturbation problem is approximated by a first-order delay differential equation with a variable deviating argument. This delay differential equation is transformed into a three-term difference equation that can be solved using the Thomas algorithm. The uniqueness and stability analysis are discussed, showing that the method is absolutely stable. An optimal estimate for the deviating argument is obtained to take advantage of the second-order accuracy of the central finite difference method in addition to the absolute stability property. Several problems having left, right, interior, or twin boundary layers are considered to validate and illustrate the method. The numerical results confirm that the deviating argument can stabilize the unstable discretized differential equation and that the new approach is effective in solving the considered class of singular perturbation problems.
Citation - WoS: 2
Citation - Scopus: 3
Abstract Random Differential Equations With State-Dependent Delay Using Measures of Noncompactness
(Vilnius Univ, inst Mathematics & informatics, 2024) Heris, Amel; Bouteffal, Zohra; Salim, Abdelkrim; Benchohra, Mouffak; Karapinar, Erdal
This paper is devoted to the existence of random mild solutions for a general class of second-order abstract random differential equations with state-dependent delay. The technique used is a generalization of the classical Darbo fixed point theorem for Frechet spaces associated with the concept of measures of noncompactness. An application related to partial random differential equations with state-dependent delay is presented.
Citation - WoS: 38
Citation - Scopus: 45
Abundant Distinct Types of Solutions for the Nervous Biological Fractional Fitzhugh-Nagumo Equation Via Three Different Sorts of Schemes
(Springer, 2020) Khater, Mostafa M. A.; Baleanu, Dumitru; Khalil, E. M.; Bouslimi, Jamel; Omri, M.; Abdel-Aty, Abdel-Haleem
The dynamical attitude of the transmission for the nerve impulses of a nervous system, which is mathematically formulated by the Atangana-Baleanu (AB) time-fractional FitzHugh-Nagumo (FN) equation, is computationally and numerically investigated via two distinct schemes. These schemes are the improved Riccati expansion method and B-spline schemes. Additionally, the stability behavior of the analytical evaluated solutions is illustrated based on the characteristics of the Hamiltonian to explain the applicability of them in the model's applications. Also, the physical and dynamical behaviors of the gained solutions are clarified by sketching them in three different types of plots. The practical side and power of applied methods are shown to explain their ability to use on many other nonlinear evaluation equations.
Citation - WoS: 38
Citation - Scopus: 41
Abundant Periodic Wave Solutions for Fifth-Order Sawada-Kotera Equations
(Elsevier, 2020) Awan, Aziz Ullah; Osman, Mohamed S.; Baleanu, Dumitru; Alqurashi, Maysaa M.; Tahir, Muhammad
In this manuscript, two nonlinear fifth-order partial differential equations, namely, the bidirectional and 2D-Sawada-Kotera equations are analytically treated using an extended form of homoclinic process. In the presence of a bilinear form, novel periodic waves with different categories including periodic soliton, solitary and kinky solitary wave solutions are constructed. In the meantime, The diverse features and mechanical qualities of these acquired solutions are elucidated by 3D figures and some contour plots.
Citation - WoS: 2
Academic Mobbing in Turkey and Suggestions for Solutions: Content Analysis of Graduate Theses
(Tuba-turkish Acad Sciences, 2019) Erdemir, Burcu
The effects of globalization on various sectors around the world are reflected in academia through competition, diminishing job security and faculty collegiality, and changing managerial understanding which causes academics to feel pressured to maintain the balance between teaching and research. This transformation inevitably has made the concepts explained by Foucault as "the power exerciser" and "the subject of power" more apparent, as demonstrated by conflicts and mobbing cases. The aim of this study is to review all the master's theses and doctoral dissertations written in Turkey to pin down what has been done until now on mobbing and to form a reference point. Upon searching for certain key words on the website of Council of Higher Education Thesis Center in June 2017, 655 theses on mobbing in various sectors with diverse participant groups were detected. After examining these theses in terms of their participants, it was found out that 29 of them, written between 2005 and 2017, addressed the issue of mobbing among academics. Of these, 26 theses, written between 2006 and 2016, were included in the study. The findings of these theses indicate that while there is 4-100% mobbing in the state and the foundation universities, younger people, singles, and women are more vulnerable to mobbing regarding self-expression, social relations, and communication, and they prefer to remain silent in the face of this issue. Besides, there is a negative relationship between mobbing and seniority, title, organisational justice, trust, commitment, and job-satisfaction. The primary causes of mobbing in academia are nepotism, poor leadership, unhealthy organisational culture, solidarity, andlack of communication. This study is expected to contribute to the formation of a conceptual framework about academic mobbing for the future studies and to expediting the process of taking measures for the eradication of the problem.
Citation - WoS: 14
Citation - Scopus: 17
An Accurate Approximate-Analytical Technique for Solving Time-Fractional Partial Differential Equations
(Wiley-hindawi, 2017) Salahshour, S.; Ahmadian, A.; Ismail, F.; Baleanu, D.; Bishehniasar, M.
The demand of many scientific areas for the usage of fractional partial differential equations (FPDEs) to explain their real-world systems has been broadly identified. The solutions may portray dynamical behaviors of various particles such as chemicals and cells. The desire of obtaining approximate solutions to treat these equations aims to overcome the mathematical complexity of modeling the relevant phenomena in nature. This research proposes a promising approximate-analytical scheme that is an accurate technique for solving a variety of noninteger partial differential equations (PDEs). The proposed strategy is based on approximating the derivative of fractional-order and reducing the problem to the corresponding partial differential equation (PDE). Afterwards, the approximating PDE is solved by using a separation-variables technique. The method can be simply applied to nonhomogeneous problems and is proficient to diminish the span of computational cost as well as achieving an approximate-analytical solution that is in excellent concurrence with the exact solution of the original problem. In addition and to demonstrate the efficiency of the method, it compares with two finite difference methods including a nonstandard finite difference (NSFD) method and standard finite difference (SFD) technique, which are popular in the literature for solving engineering problems.
Citation - WoS: 9
Citation - Scopus: 11
An Accurate Predictor-Corrector Nonstandard Finite Difference Scheme for an Seir Epidemic Model
(Hindawi Ltd, 2020) Ahmad, Riaz; Farooqi, Rashada; Alharbi, Sayer O.; Baleanu, Dumitru; Rafiq, Muhammad; Ahmad, M. O.; Farooqi, Asma
The present work deals with the construction, development, and analysis of a viable normalized predictor-corrector-type nonstandard finite difference scheme for the SEIR model concerning the transmission dynamics of measles. The proposed numerical scheme double refines the solution and gives realistic results even for large step sizes, thus making it economical when integrating over long time periods. Moreover, it is dynamically consistent with a continuous system and unconditionally convergent and preserves the positive behavior of the state variables involved in the system. Simulations are performed to guarantee the results, and its effectiveness is compared with well-known numerical methods such as Runge-Kutta (RK) and Euler method of a predictor-corrector type.

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