Scopus İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://gcris.yasar.edu.tr/handle/123456789/11290

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A Bus Crew Scheduling Problem with Eligibility Constraints and Time Limitations
(Elsevier B.V., 2017) Hande Oztop; Uǧur Eliiyi; D. T. Eliiyi; Levent Kandiller
In this study we consider a real life crew scheduling problem (CSP) of a public bus transportation authority where the objective is to determine the optimal number of different types of crew members with a minimum cost that cover a given set of tasks regarding working and spread time limitations. Each driver has a spread time limit from the start time to the end time of his/her shift including the idle times. Additionally a driver cannot exceed the maximum total working time limit. The processing times of the tasks assigned to each driver are included in his/her working time as well as the sequence-dependent setup times. As our study is inspired from a real life CSP the tasks can require different types of vehicles that require different crew capabilities. Therefore there are several crew classes based on the competencies required to use certain vehicle types inducing eligibility constraints in the problem. We formulate a Tactical Fixed Job Scheduling Problem based binary programming model for the problem. In the formulation we consider only processing times of tasks as working time. In order to avoid defining an additional sequence control variable that explodes the model size and in turn ruins solution performance we develop an iterative valid inequality generation scheme which eliminates task sequences exceeding the total working time when setup times are included. The performance of the developed model is investigated through a comprehensive experimentation and the numerical results are reported. The results show that our optimal seeking solution procedure is quite effective in terms of solution time for instances with up to 120 tasks. © 2017 Elsevier B.V. All rights reserved.
A comparative study on the exergoeconomic analysis of textile dryers using speco method
(2012) Ahmet Çay; Işik Tarakçioǧlu; A. Hepbasli
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. © 2012 Elsevier B.V. All rights reserved.
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.
A Comprehensive Overview of Foreign Language Teachers' Professional Development: Self-directed and Institutional Professional Development Activities of English Teachers in Turkey
(Turkish Education Association, 2024-07-30) 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 - Scopus: 15
A Conceptual Framework for Food Loss and Waste in Agri-Food Supply Chains: Circular Economy Perspective
(Springer, 2021) Yasanur Kayikci; Nazlican Gozacan; Çisem Lafci; Yigit Kazancoglu; Kayıkcı, Yaşanur; Gözaçan, Nazlıcan; Lafcı, Çisem; Kazançoğlu, Yiğit
The importance given to Circular Economy (CE) has further increased in the Agri-Food Supply Chain (AFSC) to combat the challenges of food loss and waste which could be caused by various reasons such as poor stock management economic behavior and also the occurrence of COVID-19 outbreak. The transition from linear to circularity can also enable competitive sustainability from farm to fork in AFSC which consists of different stages: farmers food processors food distributors food retailers consumers. Food loss mainly occurs in AFSC at near-farm stages (i.e. harvesting processing) while food waste happens in AFSC at near-fork stages (i.e. retail post-consumption). Thus 6Rs (remanufacture redesign reduce recycle reuse and recover) of CE principles can offer various benefits to close the loop of the wastages along with the AFSC. In this chapter a conceptual framework for circularity in the AFSC is proposed considering the 6Rs. Furthermore this framework also supports the Sustainable Development Goals. The applicability of the proposed framework is examined and discussed in the case of Turkey using SWOT Analysis. Key findings indicate that there is confusion about food loss and waste issues in Turkey. In addition the solutions and developments for FLW problem are generally focused on food waste. © 2021 Elsevier B.V. All rights reserved.
A Differential Evolution Algorithm for the Extraction of Complex Natural Resonance Frequencies of Electromagnetic Targets
(SPRINGER-VERLAG BERLIN, 2011) Mustafa Secmen; M. Fatih Tasgetiren; Secmen, Mustafa; Tasgetiren, M. Fatih; DS Huang; Y Gan; V Bevilacqua; JC Figueroa
This paper presents a differential evolution algorithm in order to find unique resonance frequencies of an electromagnetic target in the resonance scattering region. These frequencies are estimated from the roots of Laplace transform of a specially designed incident signal. The parameters of the signal are computed with an intelligent differential evolution (DE) algorithm. The algorithm searches for minimization of the scattered signal's energy in late-time region which is main fitness function in the algorithm. The proposed algorithm is demonstrated for a scattered signal of a dielectric sphere having several poles. The acquired pole results show very good agreement with theoretical expectations. Besides the differential evolution algorithm has higher accuracy as compared to a similar method which utilizes from genetic algorithm.
Citation - WoS: 5
Citation - Scopus: 8
A Dynamic Berth Allocation Problem with Priority Considerations under Stochastic Nature
(SPRINGER-VERLAG BERLIN, 2012) Evrim Ursavas Guldogan; Onder Bulut; M. Fatih Tasgetiren; Tasgetiren, M. Fatih; Guldogan, Evrim Ursavas; Bulut, Onder; D Huang; Y Gan; P Gupta; MM Gromiha
Stochastic nature of vessel arrivals and handling times adds to the complexity of the well-known NP-hard berth allocation problem. To aid real decision-making under customer differentiations a dynamic stochastic model designed to reflect different levels of vessel priorities is put forward. For exponential interarrival and handling times a recursive procedure to calculate the objective function value is proposed. To reveal the characteristics of the model numerical experiments based on heuristic approaches are conducted. Solution procedures based on artificial bee colony and genetic algorithms covering both global and local search features are launched to improve the solution quality. The practical inferences led by these approaches are shown to be helpful for container terminals faced with multifaceted priority considerations.
Citation - WoS: 13
Citation - Scopus: 15
A General Variable Neighborhood Search Algorithm for the No-Idle Permutation Flowshop Scheduling Problem
(SPRINGER-VERLAG BERLIN, 2013) M. Fatih Tasgetiren; Ozge Buyukdagli; Quan-Ke Pan; Ponnuthurai Nagaratnam Suganthan; Tasgetiren, M. Fatih; Suganthan, Ponnuthurai Nagaratnam; Buyukdagli, Ozge; Pan, Quan-Ke; BK Panigrahi; PN Suganthan; S Das; SS Dash
In this study a general variable neighborhood search (GVNS) is presented to solve no-idle permutation flowshop scheduling problem (NIPFS) where idle times are not allowed on machines. GVNS is a metaheuristic where inner loop operates a variable neighborhood descend (VND) algorithm whereas the outer loop carries out some perturbations on the current solution. We employ a simple insert and swap moves in the outer loop whereas iterated greedy (IG) and iterated local search (ILS) algorithms are employed in the VND as neighborhood structures. The results of the GVNS algorithm are compared to those generated by the variable iterated greedy algorithm with differential evolution (vIG_DE). The performance of the proposed algorithm is tested on the Ruben Ruiz' benchmark suite that is presented in http://soa.iti.es/rruiz. Computational results showed that the GVNS algorithm further improved 85 out of 250 best solutions found so far in the literature.
Citation - Scopus: 2
A Long-term Period Performance Assessment of a Building Integrated Photovoltaic System
(EDP Sciences, 2019) Mustafa Araz; Emrah Biyikt; A. Hepbasli; Hepbasli, Arif; Araz, Mustafa; Biyikt, Emrah; N. Caetano
Building Integrated Photovoltaic (BIPV) systems can be defined as PV modules which can be integrated in building's envelope by replacing conventional building materials such as windows tiles etc. and have an impact on the functionality of the buildings. Considering the huge share (40%) of buildings in total energy consumption and nearly zero-energy building target of the European Union (EU) BIPV systems present a sustainable solution and have gained increased interest in last years. In this study the performance of a BIPV system which was installed on Feb. 8 2016 on the façade of a campus building at Yasar University Izmir Turkey within the framework a EU/FP7 project and has a capacity of 7.44 kWp is evaluated for a three-year period using first and second laws of thermodynamics. Within this context real (experimental) monthly and yearly electricity productions are determined and compared with the results obtained from the simulations. Energy and exergy efficiencies and performance ratios of the system are also calculated based on the cell and total areas. © 2019 Elsevier B.V. All rights reserved.
Citation - Scopus: 1
A New Perspective for Construction Supply Chains in Digital Era
(UNIV TUN HUSSEIN ONN MALAYSIA, 2024-03-03) Ozlem Koctas-Cotur; Yesim Deniz Ozkan-Ozen; Yucel Ozturkoglu; Ozkan-Ozen, Yesim Deniz; Ozturkoglu, Yucel; Koctas-Cotur, Ozlem
The construction industry is a highly labor-intensive industry with a low degree of automation and digitization. However as in the manufacturing industry a 'new order' is emerging for the way the construction industry works today. This study aims to present the transformation of construction supply chains (CSCs) in Industry 4.0 by considering each supply chain stage separately where the main purpose is to determine the criteria for the integration of the CSC with the Industry 4.0 perspective. A literature review and a Delphi study were conducted and thirteen criteria are proposed to show the integration of Industry 4.0 aspects and CSC stages. Furthermore one of the multi -criteria decision -making (MCDM) methods the Best -Worst method is used to prioritize the criteria for guiding future implications during the transformation of construction supply chains. Among the six CSC stages the design stage is the most important from the Industry 4.0 perspective. In addition client collaboration by ICT (BIM) during the design phase is the most important sub -factors' overall rank. Although there is a limited number of studies on the CSC there are no empirical studies addressing the current digital age approach. As a result there is a significant gap in the construction literature and a thorough assessment of the building supply chain in an Industry 4.0 setting is lacking. To the best of the authors' knowledge this is the first study to illustrate the transformation of CSCs in Construction 4.0 by looking at each supply chain stage separately.
Citation - WoS: 2
Citation - Scopus: 3
A novel approach to e-learning: Yasar university e-Learning system (YES)
(Academic Conferences Limited info@academic-conferences.org, 2013) Ibrahim Zincir; Melih Zeytinoǧlu; Tohid Ahmed Rana; Samsun Mustafa Basarici; Basarici, Samsun; Zincir, Ibrahim; Rana, Ahmed; Zeytinoglu, Melih
Since 2009 every student who attends Yasar University (Izmir Turkey) regardless of their department has to take part in seven courses (Human Sciences Research Culture Design Culture Aesthetic Culture Ethic Culture Project Culture and a Social Responsibilities Project) defined as University Foundation Courses (UFND). These courses are part of the university's effort to graduate students who are not only hard-working and respectable but also who are responsible and beneficent to society and the environment that they are living in. Approximately 4000 students attend these courses every term which in return results in certain challenges. One of the more pressing challenges is shortage of lecturers and classrooms which is the root of a more visible problem, the complexity and difficulty of the timetable for the whole university. Hence in January 2012 it was decided that a new approach was needed. At the start of the 2012-2013 academic year a novel E-learning system was introduced to offer these seven courses online. Yasar University E-Learning System (YES) differs from its peers in one important aspect: YES assesses the students continuously. YES does this by not only monitoring but also by encouraging them to get involved in the courses much more actively than any other system. In addition to the assessment of the students continuously the new system evaluates the effectiveness of the users of the system by requiring them to attend the offered forums and live discussions with lecturers at least two times a week. This paper discusses the structure and the implementation of YES and the experiences so far. Furthermore the paper draws some comparisons between YES and other popular E-learning systems. © 2014 Elsevier B.V. All rights reserved.
Citation - WoS: 6
Citation - Scopus: 8
A novel arc-routing problem of electric powered street sweepers with time windows and intermediate stops
(Elsevier B.V., 2019) Cansu Yurtseven; Mahmut Ali Gökçe; Gokce, Mahmut Ali; Yurtseven, Cansu; D. Ivanov , A. Dolgui , F. Yalaoui
Waste collection is an important public service performed by municipalities. Powered street sweeping is an important part of waste collection. Recently electric powered street sweepers are used at an increasing rate for due to their energy efficiency. It is important to provide this public service at a minimum cost. We propose a novel mathematical model for determining routing of electric powered street sweepers considering a heterogeneous fleet with different capacities and battery levels to perform a predetermined service with realistic operational constraints. The objective is to minimize energy consumption used to provide the service travelling and disposal operations. © 2021 Elsevier B.V. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 4
A novel mobile epilepsy warning system
(SPRINGER-VERLAG BERLIN, 2006) Ahmet Alkan; Yasar Guneri Sahin; Bekir Karlik; Alkan, Ahmet; Karlik, Bekir; Sahin, Yasar Guneri; A Sattar; BH Kang
This paper presents a new design of mobile epilepsy warning system for medical application in telemedical environment. Mobile Epilepsy Warning System (MEWS) consists of a wig with a cap equipped with sensors to get Electroencephalogram (EEG) signals a collector which is used for converting signals to data Global Positioning System (GPS) a Personal Digital Assistant (PDA) which has Global System for Mobile (GSM) module and execute Artificial Neural Network (ANN) software to test current patient EEG data with pre-learned data and a calling center for patient assistance or support. The system works as individual sensors obtain EEG signals from patient who has epilepsy and establishes a communication between the patient and Calling Center (CC) in case of an epileptic attack. MEWS learning process has artificial neural network classifier which consists of Multi Layered Perceptron (MLP) neural networks structure and back-propagation training algorithm.
Citation - Scopus: 11
A novel planar scissor structure transforming between concave and convex configurations
(Wit Press, 2017-06-01) Müjde Yar; Koray Korkmaz; Gökhan Kiper; Feray Maden; Yenal Akgün; Engin Aktaş; Korkmaz, K.; Yar, M.; Kiper, G.; Akgün, Y.; Aktaş, E.; Maden, F.
In this paper a novel two-dimensional scissor structure that transforms between concave and convex configurations is presented. The structure is designed by a method of assembling kite or anti-kite loops in the flat configuration. Angulated units are generated from the assembled loops. Finally a new angulated scissor unit is introduced in order to design the novel scissor structure. © 2023 Elsevier B.V. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 2
A Parallel Connected Hybrid Microstrip-Substrate Integrated Waveguide Bandstop Filter
(KAUNAS UNIV TECHNOLOGY, 2023-12-22) Kemal Guvenli; Sibel Yenikaya; Mustafa Secmen; Guvenli, Kemal; Yenikaya, Sibel; Secmen, Mustafa
This study presents an original parallel connected hybrid microstrip-substrate integrated waveguide (PCHMSIW) bandstop filter. A low-pass filter implemented on a microstrip structure and a SIW-based high-pass filter are connected in parallel to each other. In this way the aim is to obtain a bandstop filter in the novel hybrid design. The parallel connected hybrid microstrip-substrate integrated waveguide (PCHM-SIW) bandstop filter is synthesised simulated and produced. The effects of connecting filters in parallel are discussed. It is seen from the results of CST Studio Suite simulation that PCHM-SIW bandstop filter has a bandwidth of 2.85 GHz and a center frequency of 4.26 GHz. The frequency change rate of the center frequency between simulation and measurement is 7.02 % where it is just 3.76 % for the deviation in bandwidth. The results of the simulation and those of the measurement are close to each other. These results converge to ideal analytical results.
A parallel cyber universe: Botnet implementations over TOR-like networks
(Curran Associates Inc., 2017) Hüseyin Yaǧci; Cagatay Yucel; Ahmet Hasan Koltuksuz; Yüce, Çaǧatay; Yaǧci, Hüseyin; Koltuksuz, Ahmet; M. Scanlon , N.-A. Le-Khac
The first bot implemented in the history of computers was the Eggdrop (Fisher J 1998). The first instance of this kind was benign, it was an automated management tool for Internet Relay Chat (IRC) rooms. It wasn't much later when Internet users experienced the first botnet attack. The GTbot family was the first known malicious automated attack network on IRCs (Bächer et al. 2009) and new era for bots had begun. Botnets can be practically defined as a network of infected smart devices. As a result of the infiltration attacks made on a victim's computer with different malwares and zero-day attacks the control of the computer is confiscated without the victim being aware of it. Confiscated machines are connected to Command and Control (C&C) centers. In the case of a single infection this attack is nothing more than a data theft or privilege escalation. However when the number of the infected devices scales up to thousands the attack becomes a mass destruction weapon on global companies' networks. Amazon Spotify Twitter and many more companies were affected by DDoS attacks by the Mirai botnet in October 2016 (Allison Nixon John Costello 2016). The Mirai botnet was conducted by a malicious network utilizing the IoT devices. Moreover an even worse fact was the announcement of more similar botnet attacks after that October (Paganini 2016 Anon 2016). Today honeypot-based signature-based and host-based defenses as well as active and passive monitoring techniques are being developed against botnets (Silva et al. 2013). Botnets are fighting back for their existence by using binary obfuscation fast-flux networks domain generation algorithm (DGA) techniques and polymorphism while ciphering IP spoofing multi-hopping and email spoofing (Rodríguez-Gómez et al. 2013 Wang et al. 2016). Another important technique for botnets is to utilize The Onion Routing (TOR) networks where the communication scheme of the bot network is anonymized in the layers of the TOR scheme. The name of this network comes from a reference to the multi-layered structure of an onion. This research presents a novel implementation of a hidden botnet mechanism over like networks to The Onion Routing (TOR) ones. The focus is on creating parallel cyber universes with TOR-like structures and hiding the existence of the botnets in the blind range of the Internet. The design of such a network and the attack vector is explained in detail for the first time in the literature. © 2023 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 2
A pattern mining approach in feature extraction for emotion recognition from speech
(Springer Verlag service@springer.de, 2019) Umut Avci; Gamze Akkurt; Devrim Ünay; Unay, Devrim; Avci, Umut; Akkurt, Gamze; A.A. Salah , A.A. Salah , A. Karpov , R. Potapova
We address the problem of recognizing emotions from speech using features derived from emotional patterns. Because much work in the field focuses on using low-level acoustic features we explicitly study whether high-level features are useful for classifying emotions. For this purpose we convert a continuous speech signal to a discretized signal and extract discriminative patterns that are capable of distinguishing distinct emotions from each other. Extracted patterns are then used to create a feature set to be fed into a classifier. Experimental results show that patterns alone are good predictors of emotions. When used to build a classifier pattern features achieve accuracy gains up to 25% compared to state-of-the-art acoustic features. © 2019 Elsevier B.V. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 3
A Populated Iterated Greedy Algorithm with Inver-Over Operator for Traveling Salesman Problem
(SPRINGER-VERLAG BERLIN, 2013) M. Fatih Tasgetiren; Ozge Buyukdagli; Damla Kizilay; Korhan Karabulut; Tasgetiren, M. Fatih; Kizilay, Damla; Buyukdagli, Ozge; Karabulut, Korhan; BK Panigrahi; PN Suganthan; S Das; SS Dash
In this study we propose a populated iterated greedy algorithm with an Inver-Over operator to solve the traveling salesman problem. The iterated greedy (IG) algorithm is mainly based on the central procedures of destruction and construction. The basic idea behind it is to remove some solution components from a current solution and reconstruct them in the partial solution to obtain the complete solution again. In this paper we apply this idea in a populated manner (IGP) to the traveling salesman problem (TSP). Since the destruction and construction procedure is computationally expensive we also propose an iteration jumping to an Inver-Over operator during the search process. We applied the proposed algorithm to the well-known 14 TSP instances from TSPLIB. The computational results show that the proposed algorithm is very competitive to the recent best performing algorithms from the literature.
Citation - WoS: 2
Citation - Scopus: 2
A Proposal for a Novel e-Learning System for the Visually Impaired
(ACAD CONFERENCES LTD, 2014) Ahmed Rana; Ibrahim Zincir; Samsun Basarici; Basarici, Samsun; Rana, Ahmed; Zincir, Ibrahim; R Orngreen; KT Levinsen
According to World Health Organization (WHO) 285 million people are estimated to be visually impaired worldwide: 39 million are blind and 246 million have low vision. It is a well-known fact that for the visually impaired it is not possible to access the information via drawings and figures as there is no interpretation. In addition it is not easy to search through a passage for the relevant information as Braille takes much more time to read and finally a lot of memorization is necessary in order to achieve success in life. As standard procedures and systems for education are not sufficient for these people a novel approach is necessary. The recent advances in information and communication technologies (ICTs) have placed e-learning at the front row of education methodologies for the disabled. E-learning applications and websites specifically designed for accessibility help to improve the quality of the education without undermining the functionality and the usability. This paper first outlines the challenges and the shortcomings of e-learning schemas for the visually impaired and then proposes a novel touch screen application implemented via an effective and interactive user-friendly e-learning system.
A UHF RFID-Based System for Real-Time Production Monitoring and Tag Quality Control in the Textile Industry
(SAGE Publications Inc, 2026-01-08) Altuglu, Ogeday; Gunduzalp, Mustafa
In the textile industry, labeling errors during the production process present significant challenges for both quality control and product traceability. This study proposes a real-time RFID-based production tracking and label quality control system to address these issues. In the developed system, RFID tags attached to products are read by embedded devices equipped with RFID readers integrated into the production lines. The captured product code data is transmitted to a local server via MQTT. The server verifies the tags by querying a central database and provides instant feedback to the corresponding device. The system runs entirely over a local network and does not require an external internet connection, ensuring uninterrupted functionality even in infrastructure-limited environments. This architecture enables all devices on the production line to communicate synchronously with the server, maintaining system-wide consistency and integrity. In this way, the use of a single tag per product is ensured, and faulty tags are filtered out. Furthermore, the system evaluates tag readability to detect quality issues such as stitching errors, physical deformation and alerts the operator through feedback. As a result, defective products are identified and removed before production is completed, helping to reduce time loss, and improve overall production reliability.

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