Fen Bilimleri Enstitüsü

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Expert System for Access Telecommunication Networks
(2009) Şahin, S.; Tolun, M.R.; Baykal, Y.
Access telecommunication systems are categorized as digital subscriber line (xDSL), fiber-to-the-home (FTTH), hybrid fiber-coaxial (HFC), power line systems, local multipoint distribution system (LMDS), free space optics (FSO), satellite and worldwide interoperability for microwave access (WIMAX) systems. Basic specifications, such as the rate of information for upstream and downstream, access link length, frequency licence requirement for these access telecommunication networks are defined. Expert system analysis is applied to find out the possible systems that can be employed among the abovementioned choices of access telecommunication within the user defined inputs describing the requirements of the end user. The rule-based structure of the expert system is formed by using the Exsys expert system development tool. © 2008 IEEE.
Citation - Scopus: 4
Nonuniform Currents Flowing on a Perfectly Conducting Cylinder
(2011) Başdemir, H.D.
In this paper, we applied physical theory of diffraction (PTD) method to the perfectly electric conducting (PEC) cylinder for investigation of the scattering fields. Physical optics (PO) method was used to gain the uniform scattering field which is produced by the induced current from the incident wave on the tangential plane of the perfectly electric conducting cylinder. Nonuniform current and scattered field will be obtained by applying PTD method to the problem. As a last step of solution, nonuniform currents and nonuniform scattering fields were obtained with the assistance of the exact solution of the scattering waves from the cylinder. The scattering fields and currents are plotted numerically. © 2011 IEEE.
Expanding m-commerce possibilities through technology enabled devices
(2013) Özbey, Engin
Popular payment systems including asynchronous, online and mobile payments are investigated. Mobile phone payment systems are targeted after finding that mcommerce is projected to rise. With this increase in the market share, mobile devices are found-out to share physical wallets’ load as they can merge credit and ATM cards. The possibilities increase with the adoption of new technologies, such as NFC (Near Field Communication), so that the handsets can house loyalty, mass transport cards as well as electronically held money transfer ability. On the other side, the security issues including identity and money theft remain important although the expectations on converging physical wallets into the handsets are strong. However, this is not a definite obstacle and big service providers and vendors give signals to adopt such a technology in their services and products. As the conclusion, the thesis argues that e-commerce can expand more through additional technologies on the mobile devices.
Citation - WoS: 15
Citation - Scopus: 20
Using Containers as Storage Facilities in Humanitarian Logistics
(Emerald Group Publishing Ltd, 2014) Sahin, Aysenur; Ertem, Mustafa Alp; Emur, Emel
Purpose - The purpose of this paper is to investigate the use of freight containers to store relief items instead of operating a permanent warehouse building. Design/methodology/approach - A mathematical model is developed to determine the location and quantity of containers as well as the type and amount of relief supplies to store in order to investigate the practicality of using freight containers for storage. The model is tested using earthquake risk data, estimates of population under risk, and the distances between cities. An experimental study is performed using Turkish Prime Ministry Disaster and Emergency Management Presidency (abbreviated as AFAD in Turkish) data for total number of relief supplies. Findings - Considering the earthquake risk of possible locations, the results of the study indicate the target locations for containers. The idea of using containers as storage facilities helped beneficiaries to be reached within a short distance and in an efficient way. Research limitations/implications - The presented model is not implemented in real life disaster relief operations even if it is tested with real earthquake risk, demand and distance data. Practical implications - To apply this model in practice, the container locations within cities should be determined and managerial operations such as maintenance, environmental, and security planning have to be considered. Originality/value - This study presents the first analysis of three sub-topics' intersection: warehousing, pre-positioning in disaster relief, and containerization. To the best of authors' knowledge, containers have not been considered for storage of relief items in humanitarian logistics before.
Obstacles to activating e-learning at Iraqi universities
(Çankaya Üniversitesi, 2016) Shahoodh, Gailan
This study adopts a quantitative research approach to evaluate the research problem using collected data from a survey questionnaire administered to 124 respondents (professors, instructors, employee and students) from different Iraqi universities. Using both online and hardcopy questionnaires that were based on the TAM framework, it included questions related to the demographics of the respondents and any obstacles in activating e-learning. The reliability of the questionnaire was tested and a high degree of internal consistency was found. Our study provides an analysis of each variable using descriptive statistics. Using factor analysis, we extracted four factors (Perceived Ease of Use (PEU), Perceived Usefulness (PU), Attitude toward Using and Actual System Use (ATU), and Behavioral Intention to Use (BIU) which were used in the correlation and regression analysis. Per the results of the regression test, the impact of PEU and PU were shown to be statistically significant in predicting and explaining both ATU and BIU. The results revealed that the impact of Perceived Ease of Use and Perceived Usefulness is significantly positive in affecting the attitude and behavioral intention of Iraqi universities' users towards LMS/e-learning, which is consistent with the TAM theory. Moreover, it shows that the two factors play a significant role in the acceptance of the new technology; i.e. the LMS at Iraqi universities can help to reduce any obstacles to e-learning implementation. In addition, conclusions and suggestions for future work are highlighted
Color preferences of children in a waiting room of a hospital
(Çankaya Üniversitesi, 2017) Efkireen, Ahmad B. Musbah
The aim of this study is to understand the children's color preferences in a waiting room of a hospital and to investigate the effect of gender and culture differences on color preferences in the waiting room. The sample group consists of Turkish and Libyan children between the ages 6-17. A questionnaire was administered to the children in order to understand their color preferences and color preferences in the waiting room of the hospital. An original photograph of the waiting room with three different colored alternatives were shown to the children, and the children were asked to indicate their feelings and the most preferred waiting room according to color. The results indicated that the most preferred waiting room for the Libyan children was the green waiting room while the most preferred waiting room for the Turkish children was the white waiting room. The results of this study can be useful for interior architects, designers and hospital owners who give importance to children color preferences in the waiting rooms to reduce stress and anxiety of the children in a hospital.
Citation - Scopus: 4
Plagiarism Detection in Learning Management System
(Institute of Electrical and Electronics Engineers Inc., 2017) Sabonchi, A.K.S.; Görür, A.K.
Learning Management Systems has become one of the teaching tool same as the pen, pencil, blackboard, book, and notebook. Learning Management System (LMS) is defined and types that are derived from this system such as those focused only on the curriculum and those focuses on the management of the education system, and the combination of both are explained. The properties and features that must exist are identified and showed so that it can be called a learning management system. The name and the experiences of countries in terms of the use of this system as well as the benefits resulting from the user experiences have motivated schools and educational institutions to start the establishment of such systems. The main purpose of this study is, an online plagiarism detection system will be developed and integrated into Moodle so that it can be used by teachers to detect cheating and plagiarism cases in students submitted answers. © 2017 IEEE.
Use of content management systems in business: A comparison of open source content management systems
(Çankaya Üniversitesi, 2017) Al-Tameemi, Ahmed Abdulmahdi Hussein
There are many Content Management Systems (CMSs) that have appeared and were adopted in the mid-1990s to satisfy the needs of providing optimal solutions in organizing business website content. Due to the many controversial arguments about what CMS is appropriate for a business website, this study aims to help decision makers and IT managers in businesses to decide on the best open source CMS. In this study, the latest versions of three widely used CMSs, namely WordPress, Joomla and Drupal, have been selected according to their market share. Our methodology has four steps. In the first step, while developing comparison criteria, we published an online survey that represents a pool of 76 candidate criteria to be determined according to IT experts' opinion according to their importance. We installed CMSs on online servers and we tested these systems according to absolutely essential and important criteria determined by experts in the field. We performed a functional analysis for each system, i.e., whether a system performs a specific criterion depending on a core feature "Built-in," or the system needs to be extended with a third-party extension "Plug-in." Our criteria covered the complexity of installation, social media integration, security, performance and usability features. Lastly, usability tests were conducted using the Post-Study-System-Usability-Questionnaire tool to discover which CMS offers the easiest learning curve. We concluded that Joomla is the best among its competitors because this system outperformed the other two systems and supported most of our criteria as core features. Furthermore, Joomla combines the flexibility of Drupal and the intuitive "User Friendliness" of WordPress as it allows the creation of high-quality websites by non-technical users. Joomla also offers a moderate learning curve based on final usability test results.
Madenlerde yaşam odalarının iş sağlığı ve güvenliği üzerine etkilerinin analizi
(Çankaya Üniversitesi, 2017) Doğan, Onur
Madencilik, tarihi eskilere dayanan önemli bir uğraş alanıdır. Özellikle Sanayi Devrimiyle önemli hale gelmiştir. Buna bağlı olarak üretim miktarında ve çalışan sayısında hızlı bir artış yaşanmıştır. Bilimsel ve Teknolojik gelişme maden araçlarını kaliteli hale getirse de iş ve işçi kazalarının önüne geçmekte yetersiz kalmıştır. Bu nedenledir ki dünyada en fazla insan kaybının yaşandığı sektörlerden biri olmuştur. İş ve işçi kazalarını önleme adına ILO gibi uluslararası kuruluşlar çeşitli kriterler belirlemişlerdir. ILO'nun amacı uluslararası standartların belirlenerek sözleşmeye taraf olan ülkelerdeki çalışma ve yaşam şartlarını düzeltmektir. Bu standartlar evrensel çalışma sözleşmeleri ve tavsiye kararlarından oluşmaktadır. Çoğu ülke gibi Türkiye'de bu kriterleri referans alarak kendi yasal düzenlemelerini gerçekleştirmektedir. Ülkemizde yaşanan maden kazalarından sonra sıkça gündeme gelen ve iş güvenlik önlemlerinden biri olan yaşam odaları tez kapsamında detaylı olarak ele alınmıştır. Bu kapsamda önce yaşam odaları ile ilgili uluslararası standartlar incelenmiş, dünyadaki uygulamaları, araştırılmıştır. Ülkemizde faaliyet gösteren bir maden işletmesinde yaşam odası uygulaması kritik edilmiştir.
Emoji usage in twitter data: Analyzing users' interpretations of emoji ideograms
(Çankaya Üniversitesi, 2017) Marzoog, Dheyauldeen Abed
In conjunction with the significant growth in the use of social media, emojis have become a trending topic in informational technology related studies. New writing and communication styles using emojis are being used by people as a new language in different social media channels. This study adopts a quantitative research approach regarding emoji interpretations of users in order to evaluate the research problem using collected data from Twitter which is combined using the R program. These collected data are used in a survey questionnaire administered to 201 participants (students, staff and employees) from Çankaya University using Google Forms and shared by visiting the classes of students and by sending the survey using social media channels. This study aims to evaluate the interpretation of emojis by users. The methodology of the study depends on two parts, the first of which is the collection of data and the second using these data in a survey. The survey included questions related to the demographics of the respondents and questions about using social media and emojis. Then the remaining questions about the interpretation of the 201 participants for each of the top 100 emojis were collected from the R program as 'negative,' 'neutral' and 'positive.' Later, the study analyzed the results, which revealed that some of the emojis have different interpretations for different users.
Criteria for the selection of eco-friendly materials in interior architecture
(Çankaya Üniversitesi, 2017) Abdelslam, Wesam Awad Ali
Environmentally responsible or sustainable design has become a fundamental issue in the field of Interior Architecture, as well as other disciplines. However, the implementation of sustainability in the practice of Interior Architecture is still limited, especially regarding the selection of eco–friendly materials. In this thesis, in order to achieve a higher level of sustainability in the construction industry, a classification system for the usage of eco-friendly materials in Interior Architecture was developed. The study also includes developed guidelines, derived from the analysis of LEED Green Building Rating System and various studies in literature, regarding choosing eco-friendly materials. The criteria set out and the developed classification system for materials will be benefitted for providing a cleaner and healthier environment. By the use of these guidelines, excessive consumption of natural resources, as well as possible harmful emissions are aimed to be reduced.
A GIS-based decision support system for tourism planning and development
(Çankaya Üniversitesi, 2018) Yıldırım, Pınar
In the past twenty years, pioneering developments in information technology and communication systems worldwide have not only offered many opportunities in the fields of marketing, management and the promotion of tourism and recreational areas to businesses interested in tourism, but have also provided a sustainable advantage in competition with other businesses. Turkey has more potential for tourism and more resources than many countries, thanks both to its natural beauty and its historical and cultural wealth. The aim of this thesis is to build a web portal that is able to enhance its attractiveness through photographs or videos taken in all regions of Turkey, increase interest from domestic and foreign tourists through detailed articles about the country, and improve the accessibility of the country's resources through a system based on GIS. Developed within the scope of this thesis, the Turkey Tourist Portal can promote the country to tourists by presenting both its natural beauty and its historical and cultural wealth on a map, together with images and articles.
Cloud computing impact on communication and service sector: Iraq case study
(Çankaya Üniversitesi, 2018) Almafrchi, Sabah Salam Hussein
Rapid advancements in technology have enhanced the significance of the use of cloud technology. The deployment of cloud computing as effective technology integration has been successful, particularly across the developed states of the world. However, there have been certain behavioural issues regarding the cloud technology activation in certain developing regions, rather than the technical limitations. In the context, the current research aims to evaluate the impact of deployment of cloud computing on the communication and service sector of Iraq. Even though the cloud computing approach seems appealing, yet certain challenges of adverse extent are encountered across the states where internet penetration and technology acceptance is not considerable. Similar is the case with Iraq; hence, the researcher has targeted the communication and service sector of Iraq with respect to assessing the deployment of cloud computing. In this regard, the constructs of UTAUT model as identified dependent and independent variables of the study have been employed, in terms of conducting a multiple-item 5-point scale online survey across 251 IT experts of the targeted domain. Resultantly, it has been established that there have been certain challenges of disregarding cloud computing as an effective measure of enhancing productivity, and efficiency of the employees in a secure and feasible manner. Therefore, the study has recommended training and awareness programs that must present the credibility and integrity of cloud computing as an effective technological deployment. These programs assist accepting the cloud computing technology by the employees in the communication sector, which enables the employees, as well as the organizations, providing more efficient tasks by reducing the costs and efforts needed to perform the exact same tasks without the use of cloud computing technologies. This improvement also assists other employees and organization to accept that technology, which eventually leads to more and more acceptance to the cloud computing technology in the communication and service sector.
Decoding of Polar Codes
(Springer Science and Business Media B.V., 2019) Gazi, O.
As we explained in Chap. 1, polar encoder structures can be constructed in a recursive manner. This leads to recursive decoding structures. In [1], Arıkan proposed successive cancellation decoding algorithm for the decoding of polar codes and derived recursive expression for the decoding operations. © Springer Nature Singapore Pte Ltd. 2019.
Citation - Scopus: 5
Active Defense Strategy Against Jamming Attack in Wireless Sensor Networks
(Modern Education and Computer Science Press, 2019) Al-Shai, N.F.A.; Hassanpour, R.
Wireless Sensor Networks WSNs are being utilized increasingly nowadays due to their ability to collect data from stationary, moving, reachable or unreachable fields. Progressive developments in WSN techniques add efficiency, reliability and better power management possibility, but they are still vulnerable and sensitive to security threats. The most effective threat to WSN is DOS attacks, which are detectable but in many cases unpreventable yet. An authentication-based defensive approach against DOS attack combined with jamming attack that prevents transferring data between attacked nodes in a cluster and cluster head node is proposed in this study. The proposed method encompasses developing an algorithm with ability to bypass attacked path via alternative safe one under control of cluster head to mitigate the False Node Excluding DOS due to jamming attack. The proposed method has been experimentally tested against similar methods from the literature with arbitrary study cases. Our proposed algorithm shows promising results in mitigating False Node Exclusion DOS (FNEDOS) attack where a full recovery of the attacked node is achieved in case of isolated nodes, and improvement between 36% and 52% is obtained when the attack affects a group of nodes at proxim © 2019 MECS.
Citation - Scopus: 5
Investigating End User Errors in Oil and Gas Critical Control Systems
(Association for Computing Machinery, 2020) Alrawi, L.N.; Pusatli, T.
System availability and efficiency are critical in the petroleum sector as any fault affecting those systems may negatively impact operations resources, such as money, human resources and time. Therefore, it has become important to investigate the reasons for such errors. In this study, human error has been targeted since a number of these errors is projected to increase in the sector. The factors that affect end user behavior are investigated in addition to an evaluation of the relation between system availability and human behavior. An investigation has been performed following the descriptive methodology in order to gain insights into human error factors. Questionnaires related to software/hardware errors and errors due to the end user were collected from 81 site workers. The findings indicate a potential relation between end user behavior and system availability. Training, experience, education, work shifts, system interface, usage of memory sticks and I/O devices were identified as factors affecting end user behavior, hence system availability and efficiency. © 2020 ACM.
Adoption of Case Tools & Uml: a Local Study
(Association for Computing Machinery, 2020) Ashour, O.I.A.; Pusatli, T.
This research investigates the role of CASE tools in the software development process by considering importance of CASE in adopting a number of standards. A survey was conducted in six selected companies in Ankara in which semi-structured interviews are conducted with information system managers and developers as key informants. As results, CASE and UML are reported as being considerably used in Ankara with CASE tools being used for project members' communication and documentations. Furthermore, CASE tools have been used for some companies for documentation as parts of contracts and to follow standards such as ISO and CMMI. CASE tools are used to facilitate project developments, especially when enforced by the standards and methodologies required in the contracts. © 2020 ACM.
Citation - WoS: 22
Citation - Scopus: 22
Influence of Welding on Microstructure and Strength of Rail Steel
(Elsevier Sci Ltd, 2020) Turkbas, Osman Selim; Cogun, Can; Sarikavak, Yasin
In this study, metallurgical and mechanical aspects of cold flash butt welded rail joints were investigated. The relationship between the material characteristics and the distance to the fusion line were evaluated. Significant changes observed in grain size as it ranges 2-8 according to ASTM E 112. Hardness tests conducted and the average results of the rail head, web, and foot were recorded. According to the results, three different zones were identified including the fusion line, recrystallization zone, and transition areas. Tensile properties and strength characteristics have been investigated for the specified zones separately. Obtained experimental values were used as input parameters for the developed finite element model (FEM) to calculate stress distribution. The welded rail was subjected to realistic wheel load and stress distributions in weld were evaluated. The developed model has also been validated by comparing the theoretically obtained stress values with the experimental ones under various loading conditions. (C) 2020 Elsevier Ltd. All rights reserved.
A Model for Adopting Cloud Computing in Government Sector: Case Study in Iraq
(Nadia, 2020) Al Bajjari, Faten; Hassanpour, Reza
Cloud computing is an on-demand delivery system of computing resources, such as servers, databases, storage, networking, software, and analytics, over the Internet on a pay-for-use basis. This technology is not currently widely utilized in government institutions, especially in the case of Iraq, for different factors. The main objective of this research is to identify the most critical factors that prevent the adoption of cloud computing, through developing a conceptual model that integrates the Technology Organization, and Environment (TOE) framework, Iacovou et al.' s model, and the Diffusion of Innovation (DOI) theory. The key factors influencing the adoption of cloud technology have been determined through literature review. The results show that the most significant concerns that can have a negative impact in the decision of adoption are as follows: feasibility, trust, regulatory concerns, IT readiness, privacy, compatibility, government support, availability and reliability, industry type, security, cost, complexity, organization size, organization culture, as well as direct benefits and indirect benefits have a positive impact in the decision of cloud adoption. Moreover, the researchers used the CloudAnalyst simulator to identify the real time performance of the cloud technology environment, and applied two algorithms via this tool, namely the Analytical Hierarchy Process (AHP) technique, which used to obtain the weight of variables depending on the questionnaire results, and the Elliptic Curve Digital Signature Algorithm (ECDSA), which used to identify the privacy and security of cloud technology. Finally, the researchers have proposed guidelines to help government institutions to move to the cloud environment in an effective manner.
Citation - Scopus: 5
Deep Learning Methods With Pre-Trained Word Embeddings and Pre-Trained Transformers for Extreme Multi-Label Text Classification
(Institute of Electrical and Electronics Engineers Inc., 2021) Erciyes, N.E.; Görür, A.K.
In recent years, there has been a considerable increase in textual documents online. This increase requires the creation of highly improved machine learning methods to classify text in many different domains. The effectiveness of these machine learning methods depends on the model capacity to understand the complex nature of the unstructured data and the relations of features that exist. Many different machine learning methods were proposed for a long time to solve text classification problems, such as SVM, kNN, and Rocchio classification. These shallow learning methods have achieved doubtless success in many different domains. For big and unstructured data like text, deep learning methods which can learn representations and features from the input data wtihout using any feature extraction methods have shown to be one of the major solutions. In this study, we explore the accuracy of recent recommended deep learning methods for multi-label text classification starting with simple RNN, CNN models to pretrained transformer models. We evaluated these methods' performances by computing multi-label evaluation metrics and compared the results with the previous studies. © 2021 IEEE

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