Scopus İndeksli Yayınlar Koleksiyonu

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Citation - WoS: 4
Citation - Scopus: 4
A Canonical 3-D P53 Network Model that Determines Cell Fate by Counting Pulses
(ISTANBUL UNIV FAC ENGINEERING, 2018) Gokhan Demirkiran; Guleser Kalayci Demir; Cuneyt Guzelis; Güzeliş, Cüneyt; Demirkıran, Gökhan; Demir, Güleser Kalaycı
From a system theory perspective p53 network dynamics is interesting since it can exhibit three dynamical modes of p53 namely low-level equilibrium oscillation and high-level equilibrium. Each of these modes are associated with different cell fate outcomes: cell survival cell cycle arrest and apoptosis. The literature reveals that a high level (apoptosis) is seen only after ending the oscillation phase so called two-phase dynamics which provides the decision of apoptosis depending on the oscillation duration. This paper proposes that a negative feedback can keep time by counting the pulses of oscillation to take the decision of apoptosis or cell survival. P53DINP1 which is the mediator of this feedback is added as a variable to a 2-D oscillator model of the p53 network. The resulting canonical 3-D model successfully replicates the two-phase dynamics. That is it possesses temporary oscillatory behavior in which first oscillations (first phase) and then high level state (second phase) are observed. By introducing a new variable to the core oscillator in the p53 network this study demonstrates that p53 network can be considered a modular structure which consists of an oscillator and other variables that control this oscillator to contribute to cell fate determination.
Citation - WoS: 3
Citation - Scopus: 3
A COMPARATIVE STUDY ON THE EXERGOECONOMIC ANALYSIS OF TEXTILE DRYERS USING SPECO METHOD
(EGE UNIV, 2012) Ahmet Cay; Isik Tarakcioglu; Arif Hepbasli; Hepbaşlı, Arif; Çay, Ahmet; Tarakçıoğlu, Işık
This study reveals the exergoeconomic analysis of stenters by using Specific Exergy Costing (SPECO) method. The cost balances and auxiliary thermoeconomic relations were developed for direct gas heated (DGHS) and hot oil heated (HOHS) stenters by the application of the control volume models. The exergy cost of the evaporation of water was selected to be the main parameter. It was shown that the falling-rate period of drying led to the highest exergy costs while exergy costs varied between 0.19 US$/GJ and 0.59 US$/GJ depending on the drying periods. Increasing the exhaust air humidity ratio and the residual moisture content of the fabric outlet decreased the exergy costs linearly.
Citation - WoS: 4
Citation - Scopus: 4
A Comprehensive Evaluation of Yacht Charter Service Concept: Influence of Voyager-to-Voyager Interaction on Service Satisfaction
(GALENOS PUBL HOUSE, 2021) Neslihan Paker; Osman Gok; Paker, Neslihan; Gök, Osman
The study attempts to evaluate yacht charter service attributes considering the service quality customer satisfaction and loyalty three-leg framework. Besides visited destinations the service concept is enlarged with social servicescape dimensions of interaction quality and customer similarity for a holistic approach. A self-administered questionnaire was provided to 359 customers and the relationships in the research model were tested via structural equation modeling. The results showed that satisfaction depends on the interaction quality which is strongly related to the similarity between other customers as well as the quality of the service elements and the attractiveness of the visited destination. This study presents a pioneering research attempt focusing on the influence of customer-to-customer interaction and customer similarity on yacht charter services. Findings of the study provide a theoretical contribution highlighting the importance of customer-to-customer interaction for service appraisals of customers. Theoretical and practical implications for interaction-dominant services are discussed.
A Comprehensive Overview of Foreign Language Teachers' Professional Development: Self-directed and Institutional Professional Development Activities of English Teachers in Turkey
(Turkish Education Association, 2024) Çaǧri Özköse-Biyik; Oner Uslu; Bıyık, Çağrı Özköse; Uslu, Öner
When the literature on the professional development of English as a foreign language (EFL) teachers is examined professional development predominantly encompasses institutional activities. This study critically examines conventional definitions and practices related to the professional development of EFL teachers arguing that in line with the demands of the era teachers' professional development should also include self-directed individual activities. However for professional development activities to contribute to the ultimate goal of student learning it is important for the organizational culture in which teachers are situated to be supportive of their professional development. To seek answers to research questions about how the institutional and self-directed activities carried out by EFL teachers in Türkiye and the organizational culture influence these activities an exploratory sequential strategy was employed in the research. First qualitative data were collected and then quantitative data were collected through a survey tool developed based on the qualitative data. Comprehensive individual interviews were conducted with a total of 28 teachers across Turkey and survey data were collected from 819 teachers. The findings are presented as self-directed (unstructured) professional development activities (e.g. use of search engines reading news websites watching videos/series etc.) and institutional (structured) professional development activities (participation in national and international conferences etc.). The necessity of foreign language teachers being involved in many individual activities through self-direction beyond their participation in activities planned by institutions for the professional development of a foreign language teacher is discussed. The study proposes a comprehensive perspective on the concept of professional development related to EFL teachers and offers recommendations for the field of foreign language teacher education. © 2024 Elsevier B.V. All rights reserved.
Citation - WoS: 40
Citation - Scopus: 55
A Comprehensive Review of Feature Selection and Feature Selection Stability in Machine Learning
(GAZI UNIV, 2023) Mustafa Buyukkececi; Mehmet Cudi Okur; Buyukkececi, Mustafa; Okur, Mehmet Cudi
Feature selection is a dimension reduction technique used to select features that are relevant to machine learning tasks. Reducing the dataset size by eliminating redundant and irrelevant features plays a pivotal role in increasing the performance of machine learning algorithms speeding up the learning process and building simple models. The apparent need for feature selection has aroused considerable interest amongst researchers and has caused feature selection to find a wide range of application domains including text mining pattern recognition cybersecurity bioinformatics and big data. As a result over the years a substantial amount of literature has been published on feature selection and a wide variety of feature selection methods have been proposed. The quality of feature selection algorithms is measured not only by evaluating the quality of the models built using the features they select or by the clustering tendencies of the features they select but also by their stability. Therefore this study focused on feature selection and feature selection stability. In the pages that follow general concepts and methods of feature selection feature selection stability stability measures and reasons and solutions for instability are discussed.
Citation - Scopus: 10
A genetic algorithm to solve the multidimensional Knapsack problem
(Association for Scientific Research membranes@mdpi.com, 2013) Murat Erşen Berberler; Asli Guler; Urfat Nuriyev; Berberler, Murat Ersen; Guler, Asli; Nuriyev, Urfat G.
In this paper The Multidimensional Knapsack Problem (MKP) which occurs in many different applications is studied and a genetic algorithm to solve the MKP is proposed. Unlike the technique of the classical genetic algorithm initial population is not randomly generated in the proposed algorithm thus the solution space is scanned more efficiently. Moreover the algorithm is written in C programming language and is tested on randomly generated instances. It is seen that the algorithm yields optimal solutions for all instances. © 2020 Elsevier B.V. All rights reserved.
A new model for minimizing the electric vehicle battery capacity in electric\rtravelling salesman problem with time windows
(Tubitak Scientific & Technological Research Council Turkey, 2021) Kazım Erdoğdu; KORHAN KARABULUT; Erdoğdu, Kazım; Karabulut, Korhan
The growing pollution in the environment and the negative shift in the global climate compel authorities\rto take action to protect the environment and human health. Transportation is one of the major contributors to this\renvironmental decay. The harmful gases released to the air by the vehicles using petroleum fuel increase each day. One\rof the solutions is to make a gradual transition to electric vehicles. A major part of manufacturing an electric vehicle\ris to produce an efficient electric motor and battery for it. Reducing the manufacturing and operating costs of these\rcomponents will result in reducing the overall costs of electric vehicles. In this study a new variant of the electric\rtravelling salesman problem with time windows (E-TSPTW) was proposed. The objective function of the problem is to\rminimize the required initial battery capacity of the electric vehicle. For this goal a new energy consumption model\rconsidering the load of the vehicle was proposed with three scenarios. The proposed model was solved with a hybrid\rsimulated annealing algorithm for all these scenarios. The performance of the proposed method was compared to the\rsolutions found by a mixed integer linear programming model. The experimental results on the benchmark instances\rshow that up to a 35% reduction in initial battery capacity hence reduction in its cost is possible.\r
Citation - WoS: 5
Citation - Scopus: 10
A new warehouse design problem and a proposed polynomial-time optimal order picking algorithm
(GAZI UNIV FAC ENGINEERING ARCHITECTURE, 2018) Omer Ozturkoglu; Deniz Hoser; Hoşer, Deniz; Öztürkoğlu, Ömer
In this study we propose a new design problem that relates to orientation of cross aisles in warehouses. In this problem the main orthogonal cross aisle which is very common to be seen in warehouses to facilitate travel between locations is planned to be designed as discrete manner such as tunnels along picking aisles. Hence the problem of locating these tunnels along picking aisles so as to increase efficiency of order picking operations which is one of the most costly and the most related operations with the order delivery time in warehouses is propounded. Additionally we develop a new dynamic programming based polynomial time algorithm to calculate optimal length of order picking tour in this new design problem. Hence this algorithm provides very quick solutions even for large pick list sizes. The computational performance of this algorithm is compared with Held-Karp branch and bound algorithm which is a well-known algorithm for travelling salesman problem. Last we solve an example problem and explain how the algorithm is implemented to generate optimal tour.
Citation - WoS: 9
Citation - Scopus: 9
A novel square-root domain realization of first order all-pass filter
(Tubitak Scientific & Technological Research Council Turkey, 2010) Sinem ÖLMEZ; Uğur ÇAM; Çam, Uğur; Ölmez, Sinem
In this paper a new square-root domain first order all-pass filter based on the MOSFET square law is presented. The proposed filter is designed by using nonlinear mapping on the state variables of a state space description of the transfer function. To the best knowledge of the authors the filter is the first square-root domain first order all-pass structure designed by using state space synthesis method in the literature. The center frequency of the all-pass filter is not only attainable at megahertz frequencies but also tunable by an external bias current. The proposed filter operated 2.5 V supply voltage is constructed by current mirrors geometric mean circuits a linear transconductor circuit and a capacitor. SPICE simulations are given to approve the theoretical analysis.
Citation - Scopus: 1
A proposed model for candidate selection process in political parties based on fuzzy logic methodology
(Association for Scientific Research, 2012) METE EMİNAĞAOĞLU; Yılmaz GÖKŞEN; ONUR DOĞAN; Eminağaoğlu, Mete; Gökşen, Yılmaz; Doğan, Onur
Classical logic and classical set theorems are not sufficient enough when it isnecessary to deal with complex decision making problems which also involve humanexperiences. Some researches suggest that senior management usually makes intuitivedecisions in the process of selecting the candidates in political parties which brings outthe need to derive a new efficient robust and applicable method.In this study the qualitative characteristics and their significance level which could beused for the candidate selection process in political parties are determined. Thecandidate selection process consisting vague inputs is analyzed by fuzzy logicmethodology and a quantitative final score has been determined for the candidate. It hasbeen shown that the model provided some realistic and promising results which couldenable further studies to derive more optimized and enhanced models for similarpurposes.
A review of substrate integrated waveguide (SIW) filter architecture and filter design technologies
(GAZI UNIV FAC ENGINEERING ARCHITECTURE, 2024) Kemal Guvenli; Sibel Yenikaya; Mustafa Secmen; Güvenli, Kemal; Yenikaya, Sibel; Seçmen, Mustafa
In this review article transmission line technologies are compared in terms of loss dimension production cost ease of integration and design complexity. The basic design stages of the Substrate Integrated Waveguide (SIW) filter which stands out with its advantages among transmission lines are given. Current studies using different SIW filter technologies have been examined in the literature. The quality factors of the examined SIW filters were calculated and a comparison was made between the applied techniques. In addition the methods applied in the literature to eliminate the harmonic and high mode effects that adversely affect the SIW filter performance are examined and the results are evaluated.
A Spatial Reflection of Social Transformation: Taksim Municipal Gazino 1939
(ISTANBUL UNIV RESEARCH INST TURKOLOGY DEPT ART HISTORY, 2024) Begum Sena Onal Ozmalatyalilar; Meltem O. Gurel; Gurel, Meltem O.; Önal, Begüm Sena; Ozmalatyalilar, Begum Sena Onal; Gürel, Havva Meltem; Önal Özmalatyalilar, Begüm Sena
Taksim Municipal Gazino which hosted its visitors inside the Inonu Promenade between 1939 and 1967 was one of the leading examples of gazinos (an entertainment venue) built with the support of the state in the early republican era in Turkey. Designed by the municipality architect Ruknettin Guney within the scope of French city planner Henri Prost's Istanbul Master Plan the edifice was a quintessential example of modern architecture that epitomized the state's Westernization ideology. This article examines the gazino practice as a spatial reflection of social transformation by presenting a historical and spatial reading of the Taksim Municipal Gazino. The study analyzes the gazino structure as a power mechanism that produces secular identities by focusing on the dialectic between the spaces in the building and the experiences of its patrons. The analysis of architectural drawings photographs and literary works associated with the building on the one hand reveals how the architect operating as a cultural leader utilized architectural creation to present the Western lifestyle to society. On the other hand it indicates that Taksim Municipal Gazino served as a platform for individuals to display their modernity. Moreover the study propounds that the building contributed to the modernization process of the newly established nation-state and it has served as a spatial tool that notably strengthened the position of female regulars in the public sphere.
Citation - WoS: 1
Citation - Scopus: 2
A Symmetrical-Asymmetrical Fault Characteristics Analysis within Cogeneration Power Plant in Izmir Turkey: An Experimental Assessment
(Gazi Univ, 2022) hacer sekerci oztura; sezai polat; Polat, Sezai; Oztura, Hacer Sekerci; Sekerci Oztura, Hacer
The analysis of the short circuit should be understood very well in order to make correct designs in the power systems such as the safety of the personnel and the equipment the selection of the safety relays the circuit breaker selection and the selection of the appropriate conductor section. In this study the parameters about the short circuit and the techniques of calculating the faults in system and the necessary theoretical knowledge for the short circuit fault to be understood better have been given. The effect on the distributed generation and the grid which is caused by the possible short circuit faults have been simulated by being modeled in PSS/Sincal and by using the real grid parameters with cogeneration power plant in Izmir Turkey. The real short circuit fault results measured from the power plant and the grid and the results obtained from the software program have been compared and it has been determined that there is not a significant difference between them. Thus it has been emphasized that it is correct to simulate before investing in a power system in for the purpose of restrain the faults during the designing and working before the application. It allows the designer to design new power plant as good as plan expansion of existing power plants with higher degree of precision. Considering the prices of protection equipment which has a large part in system design this way would allow designer to reduce the cost of the protective equipment and remaining stability.
Citation - WoS: 4
Citation - Scopus: 4
African Studies in Turkey
(ULUSLARARASI ILISKILER KONSEYI DERNEGI, 2016) Elem Eyrice Tepeciklioglu; Eyrice Tepeciklioğlu, Elem; Eyrice, Elem Tepeciklioğlu
This article aims at providing an analysis of African studies as a recently emerging field of study in Turkish academia. For many years African issues had low priority in both policy and academic circles. The article argues that the recent scholarly interest in African issues is largely a product of the increasing political interest towards the continent. Although the existing literature mostly concentrates on Turkish-African relations and the study of particular African issues remain limited in number African studies in Turkey has made progress and is still evolving with an expanding and diversifying literature.
Citation - Scopus: 1
Ahşap malzemede kerf kesim tekniği üzerine bir değerlendirme
(DergiPark, 2024) Yenal Akgün; Gökçe Kırkpınar; Matthieu Joseph Pedergnana; Pedergnana, Matthieu Joseph; Kırkpınar, Gökçe; Akgün, Yenal
Ahşap geleneksel endüstriyel yapı malzemelerine kıyasla sağladığı hafiflik ve çevresel avantajlar ile mimarlar iç mimarlar ve mobilya tasarımcıları için her zaman ilham kaynağı olmuştur. Ahşap uygun kalınlıklarda doğru kesim ve üretim teknikleri uygulandığında esnek bir yapıya dönüştürülebilmektedir. Bu esnekliği kazandırma yöntemlerinden birisi de kerf kesim tekniğidir. Kerf kesim tekniği bir panel üzerinde belirli bir desen veya şekil oluşturmak için kesimler yaparak sert bir malzemeyi esnek hale getirmeye dayanır. Bu sayede karmaşık fabrikasyon yöntemlerine ve ileri teknoloji malzemelere ihtiyaç duymadan esnek ve şekil değiştirme özelliğine sahip mimari elemanlar ve mobilya ürünleri tasarlanabilir. Bu çalışmada kerf kesim tekniğinin ahşap ürünlerdeki kullanım alanları incelenerek kesim teknolojileri üretim teknikleri kesim tipleri ve desen türleri üzerinden bir sınıflandırma yapılmaktadır. Kerf kesim tekniğinin ahşap işleri alanında önemini ve son yıllarda artan ilgiyi vurgulayan bu çalışma tasarımcılar ve üreticiler için yenilikçi bir üretim yöntemi sunmaktadır. Bu teknik esnek ve estetik açıdan özgün tasarımların geliştirilmesine katkıda bulunarak ahşap ürünlerin kullanım alanlarını genişletme potansiyeline sahiptir.
Citation - WoS: 1
Citation - Scopus: 1
An Empirical Evaluation of Feature Selection Stability and Classification Accuracy
(GAZI UNIV, 2024) Mustafa Buyukkececi; Mehmet Cudi Okur; Büyükkeçeci, Mustafa; Okur, Mehmet
The performance of inductive learners can be negatively affected by high -dimensional datasets. To address this issue feature selection methods are used. Selecting relevant features and reducing data dimensions is essential for having accurate machine learning models. Stability is an important criterion in feature selection. Stable feature selection algorithms maintain their feature preferences even when small variations exist in the training set. Studies have emphasized the importance of stable feature selection particularly in cases where the number of samples is small and the dimensionality is high. In this study we evaluated the relationship between stability measures as well as feature selection stability and classification accuracy using the Pearson 's Correlation Coefficient (also known as Pearson 's Product -Moment Correlation Coefficient or simply Pearson's r ). We conducted an extensive series of experiments using five filter and two wrapper feature selection methods three classifiers for subset and classification performance evaluation and eight real -world datasets taken from two different data repositories. We measured the stability of feature selection methods using a total of twelve stability metrics. Based on the results of correlation analyses we have found that there is a lack of substantial evidence supporting a linear relationship between feature selection stability and classification accuracy. However a strong positive correlation has been observed among several stability metrics.
Citation - WoS: 33
Citation - Scopus: 36
Antecedents to supply chain innovation
(EMERALD GROUP PUBLISHING LTD, 2020) Fatma Nur Karaman Kabadurmus; Kabadurmus, Ozgur; Karaman Kabadurmus, Fatma Nur; Kabadurmuş, Fatma Nur Karaman
Purpose The purpose of this study is to examine organizational and environmental (competition capital scarcity and organization of labor) factors that affect firms' innovation activities within the supply chain. Design/methodology/approach This study empirically examines the factors that affect firms' innovation activities using firm-level data from the last round of Business Environment Enterprise Performance Surveys (BEEPS). The analysis covers major supply chain functions: production delivery and support systems. Findings The study shows that drivers of innovation vary with the type of innovation activity, as such innovation efforts across supply chain functions should prioritize strategic resources that will create competitive advantages. Our results also reveal that sustainability efforts in the Eastern Europe and Central Asia (EECA) region should prioritize labor market reforms over capital market reforms. Originality/value Current research on innovation and supply chain issues does not explicitly analyze innovations that occur in different sustainable supply chain functions and empirical studies that focus on the determinants of innovations in the supply chain network are very limited. The data used in this study cover 30 economies in EECA many of which are low- and middle-income countries and thus contribute to the implementation of sustainable practices in developing countries.
Architectural References within Émile Zola’s Novel The Ladies’ Paradise
(Istanbul Univ, FAC Letters, 2022) Zeynep Tuna Ultav; Layal Al Sahli; müge sever; Tuna Ultav, Zeynep; Sever, Muge; Sahli, Layal Al; Alsahli, Layal; Ultav, Zeynep Tuna
The depiction of space in literature is crucial to every story as it guides the reader’s imagination regarding the story’s location and the characters’ surroundings. This paper studies the relationship between architecture interiors and literary spaces by using a methodology that draws on architectural literary analysis a methodology that uses literature as a medium to define and analyze architectural spaces and cues. Specifically it investigates the connections between architectural and spatial references and their influences on societal concerns in literature – the literary space within The Ladies’ Paradise (1883) a novel by Émile Zola (1840-1902). The retail space portrayed within the novel dominates the narrative. Thus the architectural spaces are described to support the storyline. These spatial cues indicate a specific overall theme namely capitalism – an important issue to discuss within architectural discourse. Zola reveals a new perspective on the social and architectural impacts on society under capitalism through the public interior space of Ladies’ Paradise. The research also indicates the correlation between architecture public space and retailing culture through the birth of the “department store ” thus forever altering society’s ideology on retail culture. Although the novel is categorized as fictitious the representation of 19th-century retailing culture women’s role within society and the significance of architecture are shown to be realistic to that time. In conclusion this paper reveals the dialogue between architecture societal gender issues and the evolvement of retail culture through the medium of literature and derives lessons from this dialogue.
Citation - Scopus: 8
Bessel equation and Bessel function on $\\mathbb{T}(q h)$
(Tubitak, 2022) Ahmet Yantir; BURCU SILINDIR YANTIR; Zehra TUNCER; Yantır, Burcu Sılındır; Tuncer, Zehra; Yantir, Ahmet
This article is devoted to present nabla $(q h)$ -analogues of Bessel equation and Bessel function. In order to construct series solution of nabla $(q h)$ -Bessel equation we present nabla $(q h)$ -analysis regarding nabla generalized quantum binomial nabla $(q h)$ -analogues of Taylor’s formula Gauss’s binomial formula Taylor series analytic functions analytic exponential function with its fundamental properties analytic trigonometric and hyperbolic functions. We emphasize that nabla $(q h)$ -Bessel equation recovers classical $h-and q-discrete$ Bessel equations. In addition we establish nabla $(q h)4 -Bessel function which is expressed in terms of an absolutely convergent series in nabla generalized quantum binomials and intimately demonstrate its reductions. Finally we develop modified nabla $(q h)$ -Bessel equation modified nabla $(q h)$ -Bessel function and its relation with nabla $(q h)$ -Bessel function.
Citation - WoS: 4
Citation - Scopus: 10
Bi-Objective green vehicle routing problem minimizing carbon emissions and maximizing service level
(GAZI UNIV FAC ENGINEERING ARCHITECTURE, 2023) Ozgur Kabadurmus; Mehmet Serdar Erdogan; Erdoğan, Mehmet Serdar; Kabadurmus, Ozgur
In this study a bi-objective Green Vehicle Routing Problem is presented as an extension of the well-known Vehicle Routing Problem. Green Vehicle Routing Problem aims to improve routing decisions of companies using Alternative Fuel Vehicles to reduce carbon emissions. The presented problem herein has two objectives that are the minimization of total carbon emissions and the maximization of service level. While total carbon emission is assumed to be proportional to total distance cargo delivery time window violations of customers are considered as an indicator of service level. The problem was modeled as Mixed-Integer Linear Programming and epsilon-constraint method which is a multi-objective optimization method is developed to solve it. To effectively solve large problem instances a clustering-based heuristic method is proposed. The heuristic method achieved a good performance by finding near Pareto-optimal solutions that are found by the MILP model. Our proposed mathematical model and heuristic method are tested on seven realistically designed hypothetical case studies. According to the results the minimization of carbon emission and maximization of service level are two conflicting objectives. As the service level increases the number of vehicles and carbon emissions also increase. As carbon emission increases and time windows violation decreases more vehicles and alternative fuel stations are used.

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