Bilgisayar Mühendisliği Bölümü Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/58

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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.
A systematic review of gamification in the context of software development landscapes
(Çankaya Üniversitesi, 2018) Olgun, Serhan
The software development process is a complex activity that has interrelating steps to produce software products. Human related social factors such as user motivation, engagement, communication and collaboration issues affect the activities performed by software development organizations. In fact, software engineering researchers seek better ways to overcome the human related issues so as to improve the quality in software development. Consequently, research has been conducted to introduce new methodologies, techniques and concepts. As such, gamification has been introduced as a novel technique to enhance the software development process and ultimately resolve some of the identified obstacles that are related to human factors. However, there is a bias to adopt the gamification into the software development process because there are still insufficient evidences about its positive outcomes. In this study, a systematic literature review was rigorously conducted to investigate the application and to reveal the benefits of gamification in the software development landscapes. This study contributes to the area of software engineering research by proposing a classification approach to categorize gamification studies in software development landscapes. The results of this research suggest that there has been a significant increase in empirical and theoretical studies that were recently published and many positive steps being taken towards better integration of gamification in software development organizations.
Active defense strategy against jamming attack in wireless sensor networks
(Çankaya Üniversitesi, 2018) Al-Shaikh, Nawfal Fathi Abdulqader
Wireless Sensor Network WSN been utilized increasingly nowadays due to its benefits and its ability of collecting data from reachable or unreachable fields also if fields fixed or movable. Progressive developments in WSN techniques adds efficiency, reliability and better power management but it still vulnerable and sensitive to some kinds security threats. The most effective threat to WSN is DOS attacks which is detectable but unpreventable yet. An authentication defense approach against DOS attack with additional Jamming attack that prevents transferring data between attacked node in a cluster and cluster head node is considered as a base to develop an algorithm with ability of bypassing attacked path via alternative safe one under control of cluster head to mitigate the False Node Excluding DOS due to jamming attack. Both original and enhanced methods implemented using MATLAB and tested by comparing both results and behavior with arbitrary study case. Enhanced algorithm shows good response in mitigating FNEDOS attack.
An approach to improve the time complexity of dynamic provable data possession
(Çankaya Üniversitesi, 2016) Hawi, Mohammed Kadhim
In this thesis, we aim to take some actions for alleviating the fears when the data storage over outsourcing, and guarantee the integrity of the files in cloud computing. In this study, we have suggested some ideas to improve FlexDPDP scheme [13]. Particularly, proposed scheme successfully reduces the time complexity for verifying operations between the client and the server. The proposed scheme is a fully dynamic model. We involved some parameters to ensure the integrity of the metadata. In spite of the fact that auxiliary storage expenditure by Client-side (the client stores approximately 0.025% size of the raw file). The remarkable enhancement in this proposed scheme is reducing the complexity. The complexity of the communications and the computations decreased to O(1) in both Client-side and Server-side during the dynamically update (insertion, modification and deletion operations) and challenge operations.
Automatic scoring approach for Arabic short answers essay questions
(Çankaya Üniversitesi, 2017) Alfalahi, Mohammed Abdulmunem Nsaif
There are different types of questions produced by the students in their exams, such as multiple-choice questions, true/false questions, and essay questions which require free text answers. Evaluation and scoring these types of exams traditionally are an exhausting process that takes from the instructors a lot of efforts, time and activities. In this regard, applying automated approaches to evaluate and score exams are essentially required to reduce time and efforts. Although there are many commercial tools for scoring multiple-choice and true/false questions, yet there is lack of approaches and tools for evaluating and scoring essay questions, especially for the Arabic language. In this research, the aim is to propose an automated scoring approach for short answers to Arabic essay questions. The scoring process is based on the similarity between the student's answer and model answer which is provided by the instructor. Cosine similarity measures will be used for this purpose. Cosine similarity is a heuristic evolutionary measure that has succeeded to solve text to text similarity problems. In this research, we will use the word root for each keyword in the student's answer and the model answer in order to achieve accurate results. The proposed approach will be tested on a data set proposed and will be compared to other approaches.
Copyright protection using digital watermarking
(Çankaya Üniversitesi, 2017) Allayla, Hassan Fakhry Hassan
The digital techniques have greatly smooth data representation and data storage. However, the content of the data without distortion is easy to edit and copy in digital media, and this situation has resulted in a series of security problems over the widespread of using the network. For example, users can easily access, edit, or distribute data in digital media. Therefore, how to guarantee copyright protection and the integrity of the content of digital media has become an emergent issue. Digital watermarking has been proposed as a solution to the problem of resolving copyright ownership of multimedia data (image, audio, and video). In this thesis, we have proposed a copyright protection using private watermarking algorithm. The algorithm is based on multi techniques of frequency domain such as: Two Dimensional Discrete Cosine Transform and Multi-Level Two Dimensional Discrete Wavelet Transform. The proposed algorithm is built by using the secret key which is coded in the embedding side by using the secure hash algorithm (SHA-1) to increase the security of the proposed study. In this thesis, we used some fidelity criteria (such as: the peak signal to noise ratio, the normalized cross correlation and the normalized hamming distance) for measuring the performance on some different standard gray scale images. The robustness of the proposed algorithm was tested on different types of noises.
Designing and evaluating a reliable network topology by using BGP
(Çankaya Üniversitesi, 2017) Karaoğlu, Ali Murat
Border Gateway Protocol (BGP), an exterior gateway protocol, carries routing information between autonomous systems (AS) via Internet Service Providers (ISP) and the Internet. Alternative routing protocols are insufficient for use on the Internet as they are principally insufficient to cope with large routing tables. BGP is a dynamic routing protocol, and it is used by large enterprises to connect their sites via other ASs and the Internet. This study provides an implementation of BGP with some of the critical attributes using the open source network simulator, GNS3. The main aim of this study is to create a reliable and redundant topology for computer networks. In this study, route manipulation techniques are used in the network configuration process to provide redundancy. Moreover, a failover scenario is examined and tested in order to observe the effects of failovers on the routing paths. This thesis presents a useful BGP topology for real-life computer network settings
Detection of brain tumor in magnetic resonance images
(Çankaya Üniversitesi, 2018) Bufares, Anwar A.
Brain tumor is one of the serious diseases that have caused death to many people in recent years. The complex structure of the brain and its main function associated with the central nervous system and its main role in controlling most of the functions of the body makes detection of tumor a challenging task. Many techniques have been presented in the medical field in order to detect brain tumor from MRI images. In this thesis, a system is designed to detect the tumor in brain Magnetic Resonance Imaging (MRI) using a seed-based region growing algorithm (SBRG) in the segmentation process. Then after segmenting the region of interest (ROI) the texture features are extracted from the image and used to classify tumor and non-tumor tissues by the implementation of the Artificial Neural Network (ANN) classifier. The accuracy obtained by this system is 99.88%.
Developing a free DLP system for email data leakage
(Çankaya Üniversitesi, 2017) Yılmaz, Koray
Data leakage (or data loss) is a term used in the information security field to describe unwanted disclosures of information. According to DataLossDB site data breaches (leakages) in 2015 are increased dramatically. According to Risk Based Security 2016 Data Breach Report analysis, while the percentage of total breaches impact 89.5% electronic data, it is 99.6% in 2016. In this thesis, a lite e-mail data leakage prevention (DLP) solution using open source projects for e-mail data leakage has been proposed. A dirty filter script running on top of the EmailRelay server is developed and the system is tested under different loads. Different parsing architectures are tried and searched for the most efficient one. Also the proposed solution is compared with another known solution. For this purpose the community version of MyDLP server is evaluated. The outgoing e-mail with binary attachment content is analysed with Apache TIKA framework. The e-mail content which is converted to textual data, is searched for data leakage patterns using regular expressions. In most of the studies the scanned image documents are not analysed for leakage. In this study open source tools are used to convert the scanned image document to textual data; because most of the documents in the Internet are scanned confidential documents. Finally, the leaked e-mail is indexed with Elasticsearch for further contextual analysis.
Developing preventive mesurements against attacks on wireless networks
(Çankaya Üniversitesi, 2017) Ali, Ghaidaa Ahmed
Wireless Sensor Networks (WSN) and Ad Hoc networks are being using in different applications and fields of our life in the modern era. They are used in the military, medical, industrial, disaster relief, and commercial applıcatıons. Security is an important challenge in the wireless networks. Most of the wireless networks are susceptible to different attacks. In this study we address Sybil attack which uses multiple identities for a node to create the illusion that these identities come from multiple nodes. In this thesis, we propose a method to detect and prevent Sybil attacks. In our method, we consider WSN application in vehicular networks (VANET) where we detect Sybil attack without knowing the identity of the malicious node which preserves the user privacy as well. The proposed method is simulated in NS2, a widely used open source network simulator. The results are compared with the realistic test case conducted by the centralized authority DMV in terms of the detection rate and overheads.
Exploiting temporal query behavior for improving result cache accuracy in web search engines
(Çankaya Üniversitesi, 2015) Wajji, Safaa Jamaah
In Web Search Engines responding to the user queries in a timely fashion is an important requirement. One of the integral techniques to improve the response time of a search engine is caching. By storing different types of information in a fast access memory storage, caching achieves a higher availability and better response times for the search engine. Due to anonymous and global access pattern of the queries, search engines are often considered timeless frameworks. That is, search engine sites constantly respond to queries that are submitted all around the world at an almost constant pace throughout the day. During our studies, we evaluate this phenomenon and come to the conclusion that each of the data centers, which in cooperation form the general infrastructure of a general purpose search engine in fact realizes high levels of query temporality. In this work, we aim to apply and exploit the temporal behavior of the submitted queries to improve the cache accuracy by proposing a new caching architecture. To this end, we improved the state-of-the-art result caching framework Static-Dynamic Cache (SDC) and modified it in order to incorporate query temporality. Our experiments show that the proposed caching framework improves the hit rate of a result cache up to 3%, which is roughly 25% of the possible room for improvement.
Flexible platform for ROF network using advanced modulation formats based on MMF
(Çankaya Üniversitesi, 2017) Alshaykha, Ali Mustafa Ali
The connected devices in the networks are increased and the data flow between each of them is increased too. The wireless connectivity is preferable, but it has a short range and needs to enlarge the signal coverage. New wireless technologies and new access networks based on Fiber can be real solutions and it can be used with modulation techniques to achieve multi-gigabit wireless links. RF signal can be transported over optical fiber from a central location to remote antenna units by using radio over fiber (ROF). In this thesis, two test beds are demonstrated as a software simulation for the ROF, based on hybrid optical fiber and WDM. Multiple users have been also taken into consideration with the cost-effectively and bandwidth. Some passive or active components have been used with fiber length 50km. In the simulations, the ROF architecture has been simulated in C-band wavelength which has ranged between 1530 nm and 1565 nm. Then, to overcome nonlinearities problem, EDFAs are used to compensate the loss in signal. As a result of the first experiment, the average of total power for the three output signal is determined as 13.333dBm with 2.5Gbps bitrate. As a result of the second analysis with 1Gbps bitrate, the average Q-factor for two output signals is 6.0846, and the average of minimum BER is 3.7738E-10. Meanwhile, there is limitation of degradation in the signal along the whole networks by using optical and electrical amplifiers; the simulation results show that the networks are fully exploited, with low error rate.
Identifying the factors influencing truancy and using data mining for prediction
(Çankaya Üniversitesi, 2017) Albayati, Hayder Abulabbas Waheed
Truancy from school is a problem in most societies, including developed societies. This research presents the process of discovering the underlying patterns behind truancy through the use of informed discussions and data mining techniques. The main objective of the study is to identify pupils at risk of truancy, before it occurs. Several models were built using different; classification algorithms. K=1-nearest neighbour showed the highest accuracy across all algorithms. The research also showed the importance of the new factor, security situation in identifying pupils at risk of truancy.
Indoor positioning using wireless access signals
(Çankaya Üniversitesi, 2018) Altınbaş, Merve
Indoor positioning is one of the most popular topics searched in recent years, but it is not a precise and clear solution. This thesis study discusses different solutions for indoor positioning in abstract form and compares various methods. From these comparisons, Wi-Fi access points (APs) were determined to be the best method for indoor positioning. In the first phase, assuming that the locations of the APs are unknown, measurements are made at several points and information is taken, such as Wi-Fi AP signal level and mac-id. All information is saved into the database. With this information, the coordinates of the Wi-Fi APs are found using MATLAB programming language. The second phase finds the location of the person indoors using these coordinates. The aim of thesis is to achieve a position coordinate accuracy between 0 and 5 meters.
Optimizing energy consumption in wireless sensor networks by using linear programing equations
(Çankaya Üniversitesi, 2017) Sabir, Zaid Raad Sabir
Wireless Sensor Networks (WSNs) it is set of sensors deployed in a specific geographic area to sensing particular action, then relays the data to one or more base station to manage it and take actions. Sensors are tiny devices supported with limited power source generally, represented by the battery. These sensors are designed to work in unattended fields for a long time months or years. So sensor life is the most important factor in the network. We have to extend sensor lifetime as much as possible to prolong the network lifetime. Hence the network lifetime can be defined as a time from running the network till they die off first nodes in the network. Therefore, we try to make energy consumption in the network that is controlled and balanced among sensors, avoiding dies one or more sensor before the others. Many methods and manners can be used to save energy and improve network lifetime, such as data aggregation, mobile nodes, transmission power control, node deployment, and clustering. In this thesis, the problem of "unbalance energy consumption" has been studied to maximize network lifetime as much as possible in the wireless sensor networks. In such networks, all sensor nodes collect and transmit data to one base station through multi-hop communications. The nodes deployment is uniform. This situation generates heavy traffic load in the nodes near to the base station. In this study, a linear program (LP) method has been studied for modeling the theoretical features of the uniform node distribution strategies in wireless sensor networks. Our results indicated that node deployment and base station location have significant effects on the energy consumption of sensor nodes. Proposed node deployment models can affect the energy consumption and can balance energy depletion between sensor nodes
Quantitive management of information security in organizations
(Çankaya Üniversitesi, 2016) Şereflişan, Oğuzhan
Different methodology implementation to define quantitive management of information security in organizations including defining information risks quantitive approach using Lenstra and Voss [1] suggestion, annual loss expectancies like model to meet the expectations of the real world applications like cost management, finance management etc. We made some improvements on approach using ISO/IEC 27005:2011 framework. It was chosen because of a global standard and included in ISO 31000:2009, also my real life experiences deal with ISO/IEC 27001 implementation and certification.
SDN improvements and solutions for traditional networks
(Çankaya Üniversitesi, 2017) Yahya, Mohammed Amer Yahya
The new trend of the internet has led to building a digital world, where everything is connected and from any place can be accessible. Nevertheless, the management of conventional networks is complicated and difficult. Because of its static characteristics, it is hard to configure and the reconfiguration causes errors, unwanted changes, and extra load. Another reason which makes the matters harder is that the traditional networks are also perpendicularly integrated which means the control and the data planes are embedded in the same device. Software defined networking (SDN) is a new trend of networking which guarantees to alter the behavior of the current network through decoupling the control plane from the data plane and gives the networks centralized management, and offers the capability to program the network. SDN makes it simpler to produce and present new concepts in networking, simplifies network control, and facilitates network development. In this thesis, we introduce the SDN improvements and solutions for traditional networks, and explain the current networks technologies and their features. Subsequently, we present the limitations of the current networks in managements, routing, devices dependency, capital and operational cost, and rigidness and complexity. We also give the proposed solutions from SDN to these limitations, cloud computing, and heterogeneous networks. We also look at SDN applications in network routing, security and access control, Internet research, mobile device offloading, and wireless virtual machines. In addition, we introduce one of the newest trends of SDN regarding traffic engineering which is Intent-based networking. Finally, we demonstrate through simulations the benefits which are provided by SDN to traditional networks. We select a single IP layer and a multilayer optical network (MPLS over DWDM) to demonstrate the advantages of SDN managements. We deployed an SDN controller that can illustrate how the test environment configuration is carried out and how beneficial it can be. The SDN controller used was the ONOS controller.
Suspicious human activity detection from surveillance videos
(Çankaya Üniversitesi, 2017) Salem, Fathia G. Ibrahim
Video surveillance has been used from a long time to provide security in many sensitive places, so with this great progress in various aspects of life the traditional surveillance operations are facing many problems because of the large amounts of information that must be handled manually in a limited time also the possibility of information loss which can contain important things such as suspicious behaviours. So recently, a large amount of research has been conducted on video surveillance. In this thesisthesis, we will present a system to support the smart surveillance for detecting abnormal behaviours that represent security risk. The proposed algorithms are intended to detect two cases of human activities namely, walking and running. We impose no restriction on the number of people in the scene, and the direction of the motions. However, we restrict the videos to indoor colour videos, where the video are captured by one stationary camera. The moving objects which correspond to people in the scene are detected by background subtraction algorithm. We consider the displacement rate of the centroids of the segmented foreground areas and the rate of change in the size of the segmented areas as the two main features for activity classification. The proposed algorithms determine the activity type with a high accuracy rate.
Text categorization based on semantic similarity with word2vector
(Çankaya Üniversitesi, 2017) Alsamurai, Ather Abdulrahem Mohammedsaed
With an increase in online information, which is mostly in the form of a text document, there was a need to organize it so that management and retrieval by the search engine became easier. It is difficult to manually organize these documents, therefore, machine-learning algorithms can be used to classify and organize them. Mostly, they are faster, more accurate and less expensive than manual classification. Most traditional approaches of machine learning algorithms depend on the term frequency in determining the importance of the term within a document and neglect semantically similar words. For this reason, we proposed to build a classifier based on semantically similar words in text classification by using the Word2Vector model as a tool to compute the similarity between documents and capture the correct topic. So we built two models by applying three phases: the first phase, we applied preprocessing steps and the second phase, we created a dictionary for top ten categories of Reuters 21578 datasets and the final phase we trained Word2Vector model on the Wikipedia English dataset and use it to compute similarity v between documents. Depending on the results of our study, we found that the second model (the most similar predicted topic) is better than the first model (average based predicted topic) in all categories. When we compare the results of our study with other studies, we found that result of our study is a parallel to the results of other studies, but not overcome them, although these studies use feature selection in the improvement of their results while we use feature extraction in explaining of our results.
The impact of cloud computing in delivering sustainable business welfare as a part of a green ict strategy in developing countries
(Çankaya Üniversitesi, 2018) Salih, Bawar Hadi
The research is intended to assess the role of cloud computing in delivering sustainable business welfare in the developing countries, specifically in Iraq. In order to collected pertinent information, the researcher had adopted quantitative research approach. In this account, primary data was collected by conducting a survey with 152 IT professionals, working in the Iraqi companies. However, secondary data was collected through pertinent literature, by accessing Google Scholar and EBSCOhost. The collected data was analysed by using descriptive analysis. The analysis has revealed that cloud computing has great significance in the implementation of green ICT strategy; however, Iraqi companies are needed to put more focus on the improvement of their employee's skills and expertise so as to accelerate cloud adoption in Iraq

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