Araştırma Çıktıları / Research Outputs

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Citation Count: 0
19. Yüzyılda Osmanlı ve Rus İmparatorluklarında Yerel Yönetim Reformu: 1864 Zemstvo Kanunu ve 1864 Vilayet Nizamnamesi Üzerine Karşılaştırmalı Bir Analiz
(2022) Gülseven, Aslı Yiğıt; International Relations
Osmanlı ve Rus İmparatorluklarının 19. yüzyılına damga vuran modernleşme süreci her iki devlette de kapsamlı bir reform hareketi başlatmıştı. 19. yüzyılın ortasında patlak veren Kırım Harbi neticesinde, Avrupalı devletlerin baskı ve müdahalelerinden çekinen her iki imparatorlukta da iktisadi refahın sağlanması yolunda idari düzenlemelerin ya-pılması öncelikli hedef haline gelmişti. Buradan hareketle, Osmanlı ve Rus İmparator-luklarında 19. yüzyılda etkin yönetim anlayışı çerçevesinde yerel yönetimlerde bir takım idari düzenlemeler meydana getirildi. Bir yandan yerel yönetimlerin faaliyet ve yetki alanlarının genişletilmesi anlayışı benimsenirken, diğer yandan her iki imparatorlukta da merkezi yönetimin güçlendirilmesi hedeflenmiştir. Bu çalışma, Osmanlı İmparatorlu-ğunda 1864 Vilayet Nizamnamesi ve Rus İmparatorluğunda 1864 Zemstvo Kanununun taşra örgütlenmesine getirdikleri yerel yönetim reformunu ortaya koymayı ve her iki dü-zenlemeyi tarihsel arka plan, içerik, kapsam ve etkinlik yönünden karşılaştırmalı olarak değerlendirmeyi amaçlamaktadır.
Citation Count: 8
Absorption and optical conduction in InSe/ZnSe/InSe thin film transistors
(World Scientific Publ Co Pte Ltd, 2016) Al Garni, S. E.; Qasrawi, A. F.; Department of Electrical & Electronics Engineering
In this work, (n)InSe/(p)ZnSe and (n)InSe/(p)ZnSe/(n)InSe heterojunction thin film transistor (TFT) devices are produced by the thermal evaporation technique. They are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy and optical spectroscopy techniques. While the InSe films are found to be amorphous, the ZnSe and InSe/ZnSe films exhibited polycrystalline nature of crystallization. The optical analysis has shown that these devices exhibit a conduction band offsets of 0.47 and valence band offsets of 0.67 and 0.74 eV, respectively. In addition, while the dielectric spectra of the InSe and ZnSe displayed resonance peaks at 416 and 528 THz, the dielectric spectra of InSe/ZnSe and InSe/ZnSe/InSe layers indicated two additional peaks at 305 and 350 THz, respectively. On the other hand, the optical conductivity analysis and modeling in the light of free carrier absorption theory reflected low values of drift mobilities associated with incident alternating electric fields at terahertz frequencies. The drift mobility of the charge carrier particles at femtoseconds scattering times increased as a result of the ZnSe sandwiching between two InSe layers. The valence band offsets, the dielectric resonance at 305 and 350 THz and the optical conductivity values nominate TFT devices for use in optoelectronics.
Citation Count: 15
An accurate optical gain model using adaptive neuro-fuzzy inference system
(Natl inst Optoelectronics, 2009) Celebi, F. V.; Altindag, T.
This paper presents a single, simple, new and an accurate optical gain model based on adaptive neuro-fuzzy inference system (ANFIS) which combines the benefits of Artificial Neural Networks (ANNs) and Fuzzy Inference Systems (FISs). The dynamic optical gain model results are in very good agreement with the previously published experimental findings.
Citation Count: 15
An accurate optical gain model using adaptive neurofuzzy inference system
(National Institute of Optoelectronics, 2009) Çelebi,F.V.; Altindag,T.; Computer Engineering
This paper presents a single, simple, new and an accurate optical gain model based on adaptive neuro-fuzzy inference system (ANFIS) which combines the benefits of Artificial Neural Networks (ANNs) and Fuzzy Inference Systems (FISs). The dynamic optical gain model results are in very good agreement with the previously published experimental findings.
Citation Count: 10
Activation energy of metastable amorphous Ge₂Sb₂Te₅ from room temperature to melt
(Amer inst Physics, 2018) Muneer, Sadid; Scoggin, Jake; Dirisaglik, Faruk; Adnane, Lhacene; Cywar, Adam; Bakan, Gokhan; Gokirmak, Ali; Department of Electrical & Electronics Engineering
Resistivity of metastable amorphous Ge2Sb2Te5 (GST) measured at device level show an exponential decline with temperature matching with the steady-state thin-film resistivity measured at 858 K (melting temperature). This suggests that the free carrier activation mechanisms form a continuum in a large temperature scale (300 K - 858 K) and the metastable amorphous phase can be treated as a supercooled liquid. The effective activation energy calculated using the resistivity versus temperature data follow a parabolic behavior, with a room temperature value of 333 meV, peaking to similar to 377 meV at similar to 465 K and reaching zero at similar to 930 K, using a reference activation energy of 111 meV (3k(B)T/2) at melt. Amorphous GST is expected to behave as a p-type semiconductor at T-melt similar to 858 K and transitions from the semiconducting-liquid phase to the metallic-liquid phase at similar to 930 K at equilibrium. The simultaneous Seebeck (S) and resistivity versus temperature measurements of amorphous-fcc mixed-phase GST thin-films show linear S-T trends that meet S = 0 at 0 K, consistent with degenerate semiconductors, and the dS/dT and room temperature activation energy show a linear correlation. The single-crystal fcc is calculated to have dS/dT = 0.153 mu V/K-2 for an activation energy of zero and a Fermi level 0.16 eV below the valance band edge. (C) 2018 Author(s).
Citation Count: 0
An adaptive element division algorithm for accurate evaluation of singular and near singular integrals in 3D
(Turkiye Klinikleri, 2021) Bayindir,H.; Baranoğlu,B.; Yazici,A.; Software Engineering; Manufacturing Engineering
An adaptive algorithm for evaluation of singular and near singular integrals in 3D is presented. The algorithm is based on successive adaptive/selective subdivisions of the element until a prescribed error criteria is met. For evaluating the integrals in each subdivision, Gauss quadrature is applied. The method is computationally simple, memory efficient and can be applied for both triangular and quadrilateral elements, including the elements with nonplanar and/or curved surfaces. To assess the method, several examples are discussed. It has shown that the algorithm performs well for singular and near-singular integral examples presented in the paper and evaluates the integrals with very high accuracy. © TÜBİTAK
Citation Count: 0
An adaptive element division algorithm for accurate evaluation of singular and near singular integrals in 3D
(Tubitak Scientific & Technological Research Council Turkey, 2021) Bayindir, Hakan; Baranoglu, Besim; Yazici, Ali; Software Engineering; Manufacturing Engineering
An adaptive algorithm for evaluation of singular and near singular integrals in 3D is presented. The algorithm is based on successive adaptive/selective subdivisions of the element until a prescribed error criteria is met. For evaluating the integrals in each subdivision, Gauss quadrature is applied. The method is computationally simple, memory efficient and can be applied for both triangular and quadrilateral elements, including the elements with nonplanar and/or curved surfaces. To assess the method, several examples are discussed. It has shown that the algorithm performs well for singular and near-singular integral examples presented in the paper and evaluates the integrals with very high accuracy.
Citation Count: 4
Adult Education as a Stepping-Stone to Better Jobs: An Analysis of the Adult Education Survey in Turkey
(Sage Publications inc, 2018) Cilasun, Seyit Mumin; Demir-Seker, Sirma; Dincer, N. Nergiz; Tekin-Koru, Ayca; Department of Business
The objective of this article is to investigate whether adult education (AE) can be used as a tool in facilitating transitions to/in the labor market, using the cross-sectional Adult Education Survey of Turkey (2012). AE is defined as the nonformal education for individuals aged older than 25 years. The outcome of AE is measured by changing jobs for employed and finding a job for the unemployed. Concentrating on employed people, we analyze both the determinants and the outcome of participation in AE for the purpose of changing jobs; and second, concentrating on unemployed people, we analyze both the determinants and the outcome of participation in AE for the purpose of getting employed. We find that once young males who are already working participate in AE for changing work, independent of their education or how AE is financed, they can be successful in doing so. The results of the paper suggest that AE programs offered by the government can serve as a tool in increasing income of the less educated and the unemployed by facilitating their transition to the labor market.
Citation Count: 8
Alara, Türkiye denizel alanında sediman taşınımının modellenmesi
(2016) Genç, Aslı Numanoğlu; Department of Civil Engineering
Kıyı bölgelerinde yapılacak olan kıyı yapılarının kıyı morfolojisi üzerindeki etkilerini incelemek amacıyla fiziksel modeller ve sayısal modeller (sayısal benzeştirmeler) uygulanmaktadır. Sayısal modeller yardımıyla uzun süreli ölçülmüş rüzgâr hızları kullanılarak tahmin edilen dalga yüksekliği değerleri akıntı ve kıyı boyu sediman taşınım miktarlarının benzeştirilmesinde veri olarak kullanılmaktadır. Bu çalışmada, Alara Çayının Antalya Körfezine bağlandığı kıyı bölgesinde meydana gelen taşınım olaylarının nedenlerini incelemek için HYDROTAM 3D modeli kullanılarak, çalışma sahası ile çevresindeki kıyı bölgesinde, rüzgar ve dalga etkenli kıyısal akıntı düzeni ve kıyı boyu sediman taşınımı modellenmiştir. Rüzgar ve dalga iklimi çalışmalarında Alanya Meteoroloji İstasyonunun 1970-2011 yılları arası saatlik ortalama rüzgar hızları kullanılmıştır. Modelleme sonucu, kıyı boyu sediman taşınımının BatıKuzeyBatı (WNW)DoğuGüneyDoğu (ESE) doğrultusunda gerçekleştiğini göstermektedir. Çalışma bölgesinde, yıllık denizel net sediman taşınım miktarının 22237 m olduğu sonucuna varılmıştır.
Citation Count: 13
Alternative numerical modeling of a superconducting charge qubit as an eigenvalue problem
(Emerald Group Publishing Ltd, 2011) Canturk, Mehmet; Kurt, Erol; Askerzade, Iman N.; Computer Engineering
Purpose - The purpose of this paper is to employ an alternative numerical approach to analyze the characteristics of superconducting charge qubit based on a single Cooper pair box (SCB), also to study the influence of the bias current. Design/methodology/approach - The paper starts with the circuit model of a charge qubit system based on Josephson junction using Hamiltonian formalism. Corresponding Schrodinger eigenvalue problem with periodic boundary condition is converted to the Mathieu type eigenvalue problem. By applying finite difference technique, energy spectrum of charge qubit is obtained and the solutions in the lowest band are obtained in the form of Bloch waves whose superposition provides a wave packet to investigate the effect of bias current to the Coulomb blockade. Findings - The paper identifies a periodic tridiagonal Hermitian matrix form of the eigenvalue problem that is believed to be a special eigenvalue problem. The paper emphasizes that Schrodinger formalism is very, useful to model superconducting qubits systems. The investigations indicate that the bias current strongly influences the Coulomb blockade and expectation value of supercurrent (as well as number of Cooper pairs) are affected by gate voltage and energy scale. Research limitations/implications - In the present study, Schrodinger eigenvalue problem is time independent, therefore, current-voltage characteristics of the charge qubit system could not be considered. The solution technique applied here can also be used to apply other type of Josephson junction based qubits and circuits. Practical implications - The paper includes theoretical findings for the development of superconducting qubit that can be valuable for experimentalist. The result obtained in this study is useful for the comparison of experimental study with the expectation value of number of Cooper pairs as function of gate voltage. Working parameters of a SCB can be determined from the findings. Originality/value This paper fulfils the contribution of the numerical study of Schrodinger equation for the investigation of superconducting qubits under the influence of bias current.
Citation Count: 9
Analysing the Effects of Critique Techniques on the Success of Interior Architecture Students
(Wiley, 2018) Gul, Ciler Gozde Gunday; Afacan, Yasemin
In architectural design education, the most significant part in the curriculum is the design studio, where students learn how to design. Critique has a crucial role in the design studio, and in determining the best and most beneficial critique type for the architectural design education process. Student attitudes toward critiques and student satisfaction level with each critique technique are also significant. To that end, this article explores design studio learning by reviewing the design learning process and types of design critiques. Focusing on three critique techniques used in design education (desk critiques, pin-up critiques and group critiques), the article analyses correlations between student attitudes toward each technique and its contribution to the design process. Research was conducted with 84 third-year interior architecture students from the 2014-15 Fall semester at a university. No statistically significant differences were found between group and pin-up critiques in terms of students' preferences and their final performance scores; however, there was a statistically significant relationship between student preferences toward desk critiques and student success. Furthermore, the contribution of a critique technique to the design process was found to be highly correlated with student preference for this technique.
Citation Count: 23
Analysis of mirror neuron system activation during action observation alone and action observation with motor imagery tasks
(Springer, 2018) Cengiz, Bulent; Vuralli, Doga; Zinnuroglu, Murat; Bayer, Gozde; Golmohammadzadeh, Hassan; Gunendi, Zafer; Arikan, Kutluk Bilge; Department of Mechatronics Engineering
This study aimed to explore the relationship between action observation (AO)-related corticomotor excitability changes and phases of observed action and to explore the effects of pure AO and concurrent AO and motor imagery (MI) state on corticomotor excitability using TMS. It was also investigated whether the mirror neuron system activity is muscle-specific. Fourteen healthy volunteers were enrolled in the study. EMG recordings were taken from the right first dorsal interosseous and the abductor digiti minimi muscles. There was a significant main effect of TMS timing (after the beginning of the movement, at the beginning of motor output state, and during black screen) on the mean motor evoked potential (MEP) amplitude. Mean MEP amplitudes for AO combined with MI were significantly higher than pure AO session. There was a significant interaction between session and TMS timing. There was no significant main effect of muscle on MEP amplitude. The results indicate that corticomotor excitability is modulated by different phases of the observed motor movement and this modulation is not muscle-specific. Simultaneous MI and AO enhance corticomotor excitability significantly compared to pure AO.
Citation Count: 0
Analysis of Thermoluminescence Glow Peaks in β-Irradiated TlGaSeS Crystals
(Polish Acad Sciences inst Physics, 2016) Isik, M.; Yildirim, T.; Gasanly, N. M.; Department of Electrical & Electronics Engineering
Thermoluminescence properties of TlGaSeS layered single crystals were investigated in the temperature range of 280-720 K. Thermoluminescence glow curve exhibited three peaks with maximum temperatures of approximate to 370, 437, and 490 K. Curve fitting, initial rise and peak shape methods were used to determine the activation energies of the trapping centers. All applied methods resulted with energies around 0.82, 0.91, and 0.99 eV. Dose dependence of the thermoluminescence intensity was also examined for the doses in the range of 0.7-457.6 Gy. Peak maximum intensity of the observed peak around 370 K showed an increase up to a certain dose and then a decrease at higher doses. This non-monotonic dose dependence was discussed under the light of a reported model in which different kinds of competition between radiative and nonradiative recombination centers during excitation or heating stages of the thermoluminescence process are explained.
Citation Count: 1
Analyzing students' academic success in pre-requisite course chains: A case study in Turkey
(Tempus Publications, 2018) Karakaya,M.; Eryilmaz,M.; Ceyhan,U.O.; Information Systems Engineering; Computer Engineering
There are several principles which have been accepted as approaches to successful curriculum development. In spite of the differences in the proposed sequencing of topics, all approaches basically depend on the pre-requisite chains to implement their educational approach in the curriculum development for specifying the order of the subjects. In this research, two prerequisite chains representing two different curriculum development approaches are taken into consideration in a case study. The first research question considered is whether academic success in a follow-up course is positively related to success attained in the pre-requisite course. The second one is whether or not the selected curriculum development approach for deciding the chains has a significant impact on the academic success relationships between a pre-requisite and its follow-up course. To answer these questions, course data of 441 undergraduate students who graduated from the Atilim University between Fall 2001 and Spring 2015 semesters were collected and analyzed. The results indicate that the succes levels gained in a pre-requisite and its follow-up course are corelated. Moreover, different cirriculum development methods can affect this corelation. Thus, cirriculum developers should consider appropriate approaches to improve student success for deciding chaining courses and their contents. © 2018 TEMPUS Publications.
Citation Count: 0
Analyzing Students' Academic Success in Pre-requisite Course Chains: A Case Study in Turkey
(Tempus Publications, 2018) Karakaya, Murat; Eryilmaz, Meltem; Ceyhan, Ulas; Computer Engineering
There are several principles which have been accepted as approaches to successful curriculum development. In spite of the differences in the proposed sequencing of topics, all approaches basically depend on the pre-requisite chains to implement their educational approach in the curriculum development for specifying the order of the subjects. In this research, two prerequisite chains representing two different curriculum development approaches are taken into consideration in a case study. The first research question considered is whether academic success in a follow-up course is positively related to success attained in the pre-requisite course. The second one is whether or not the selected curriculum development approach for deciding the chains has a significant impact on the academic success relationships between a pre-requisite and its follow-up course. To answer these questions, course data of 441 undergraduate students who graduated from the Atilim University between Fall 2001 and Spring 2015 semesters were collected and analyzed. The results indicate that the succes levels gained in a pre-requisite and its follow-up course are corelated. Moreover, different cirriculum development methods can affect this corelation. Thus, cirriculum developers should consider appropriate approaches to improve student success for deciding chaining courses and their contents.
Citation Count: 0
Anatomical and Clinical Evaluation of Tympanic Tegmen and Mastoid Bone with Multidetector Computed Tomography
(Soc Chilena Anatomia, 2023) Sever, Sinem Nur; Cetin, Huseyin; Caliskan, Selma; Akkasoglu, Sinem; Basic Sciences
Tegmen level and mastoid bone thickness are important parameters of surgical risk in middle ear and mastoid region surgeries. This retrospective cohort study was conducted to provide a risk classification for the mastoid and middle ear regions. The study population comprised of 300 patients who underwent multidetector computed tomography (MDCT) for various indications. Patients with no pathology that disrupted the structure of the temporal region were included in the study. A risk classification was generated by analyzing the data obtained from mastoid and tympanic tegmen depths and the mastoid bone thickness by MDCT. The mastoid and tympanic tegmen were lower on the right side than on the left. In women, the right-sided mastoid bone thickness and mastoid tegmen were lower, and low-level tympanic and mastoid tegmen on the left and thin right mastoid bones were more common. According to the risk classifications for mastoid and middle ear region surgeries, women demonstrated a higher risk than men. In addition, as the thickness of the mastoid bone increased, the levels of the mastoid and tympanic tegmen increased. The present study provides a proper risk classification that may be helpful for preoperative risk assessment prior to middle ear and mastoid region surgery.
Citation Count: 0
ANN-assisted forecasting of adsorption efficiency to remove heavy metals
(Tubitak Scientific & Technological Research Council Turkey, 2019) Buaısha, Magdi; Balku, Şaziye; Yaman, Şeniz Özalp; Energy Systems Engineering; Chemical Engineering
In wastewater treatment, scientific and practical models utilizing numerical computational techniques suchas artificial neural networks (ANNs) can significantly help to improve the process as a whole through adsorption systems.In the modeling of the adsorption efficiency for heavy metals from wastewater, some kinetic models have been used such as pseudo first-order and second-order. The present work develops an ANN model to forecast the adsorption efficiency of heavy metals such as zinc, nickel, and copper by extracting experimental data from three case studies. To do this, we apply trial-and-error to find the most ideal ANN settings, the efficiency of which is determined by mean square error (MSE) and coefficient of determination (R2). According to the results, the model can forecast adsorption efficiency percent (AE%) with a tangent sigmoid transfer function (tansig) in the hidden layer with 10 neurons and a linear transferfunction (purelin) in the output layer. Furthermore, the Levenberg–Marquardt algorithm is seen to be most ideal for training the algorithm for the case studies, with the lowest MSE and high R2 . In addition, the experimental results and the results predicted by the model with the ANN were found to be highly compatible with each other.
Citation Count: 0
Annealing Effect on Dark Electrical Conductivity and Photoconductivity of Ga-In-Se Thin Films
(Polish Acad Sciences inst Physics, 2018) Isik, M.; Gullu, H. H.; Department of Electrical & Electronics Engineering
Dark-conductivity and photoconductivity properties of thermally evaporated Ga-In-Se (GIS) thin films were investigated in the temperature range of 80-430 K. All measurements were performed on as-grown and annealed GIS thin films at 300 and 400 degrees C to get information about the effect of the annealing temperature on the conductivity properties. Room temperature conductivity was obtained as 1.8 x 10(-8) Omega(-1) cm(-1) for as-grown films and increased to 3.6 x 10(-4) Omega(-1) cm(-1) for annealed films at 400 degrees C. Analysis of the dark-conductivity data of as-grown films revealed nearly intrinsic type of conductivity with 1.70 eV band gap energy. Temperature dependent dark conductivity curves exhibited two regions in the 260-360 and 370-430 K for both of annealed GIS films. Conductivity activation energies were found as 0.05, 0.16 and 0.05, 0.56 eV for films annealed at temperatures of 300 and 400 degrees C, respectively. The dependence of photoconductivity on illumination intensity was also studied in the range from 17 to 113 mW/cm(2).
Citation Count: 16
Applicability of Weyuker's Properties on OO Metrics: Some Misunderstandings
(Comsis Consortium, 2008) Misra, Sanjay; Akman, Ibrahim; Computer Engineering
Weyuker's properties have been suggested as a guiding tool in identification of a good and comprehensive complexity measure by several researchers. Weyuker proposed nine properties to evaluate complexity measure for traditional programming. However, they are extensively used for evaluating object-oriented (OO) metrics, although the object-oriented features are entirely different in nature. In this paper, two recently reported OO metrics were evaluated and, based on it; the usefulness and relevance of these properties for evaluation purpose for object-oriented systems is discussed.
Citation Count: 3
APPLICATION OF FNBDT/SCIP PROTOCOL ON LOCAL AREA NETWORK AND DETERMINATION OF LIMIT VALUES
(Gazi Univ, Fac Engineering Architecture, 2010) Dilli, Orkun; Akcam, Nursel; Koyuncu, Murat; Information Systems Engineering
Fast progress in technologies affects all the domains as well as the communication systems. Different types of systems or devices are developed and given to the services without losing time. Although these progresses, in general, have positive effects sometimes they may cause some problems. One of these problems is that the different terminal devices based on ISDN, PSTN and IP cannot communicate end-to-end with each other in a seamless secure way. In this study, FNBDT (Future Narrow Band Digital Terminal)/SCIP (Secure Communication Interoperability Protocol) protocol, which is developed for end-to-end secure communication of different terminal devices communicating on different networks, is tested from different perspectives using terminal emulator on IP Networks. These types of study have great importance in terms of providing some feedbacks to the development of FNBDT/SCIP and, as one of the initial work on this topic, this study will contribute to the future works in the area.

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