Matematik ve Bilgisayar Bölümü Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/222

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A comprehensive comparison of NOSQL and relational database management systems
(Çankaya Üniversitesi, 2017) Taha, İhsan Ahmed
In the last four 'decades, relational database management systems have been used widely to manage structured data in different disciplines. Nowadays, data resources increase rapidly in different forms (including structured, semi-structured and even unstructured data), requiring us to find another way to manage data. NoSQL database management systems previously were exhibited a few years ago, to meet the requirements of a variety of data forms. Many papers, and blogs have claimed that there is a trade-off between using relational database systems and non-relational database systems (NoSQL). In this study, we propose a novel investigation of the performance of relational and non-relational database systems in terms of the main operations that every database performs, such as insertion, reading, updating, and deleting by using the recent version of Yahoo Cloud Serving Benchmark (YCSB-0.9.0) in order to evaluate the performance of MySQL (RDBM) versus Mongo DB and Apache Cassandra (NoSQL). A testing environment is set up for each workload and the responses for each database management system used in the study are examined for each workload. It is worth mentioning that, although we use the latest version of Yahoo Cloud Serving Benchmark, it does not support the latest release of most database management systems, be they relational or non-relational. The results of this study show that the performance of each system differs due to the differences in their respective data storing mechanisms. In addition, the results of this study present the weaknesses and strengths of each database system used in the study.
A genuine origin and language for the universal principles of architecture
(2015) Acar, Aktan
Today, architectural theories are replaced by instant discoursive positions, which are mainly overwhelmed by a crisis of meaning and legitimacy. The examination of the history of architectural theories showed that those instant positions are based on the architectural theories of the 18th century. The reverse-chronological investigation of the theories of the 18th century has revealed the emancipation of architecture from its metaphysic knowledge, which distanced the theory from its origins dissociatively, in the 17th century as the reason that crisis. That knowledge was defining the particulars of architectural theory, such as origin, meaning, character, taste, and form from antiquity to the late 17th century. The research showed that those particulars constitute the universals of architecture. Their genuine origin and language defining them were structured by Vitruvius in the 1st century BC on the basis of six essential concepts: order, arrangement, symmetry, eurhythmy, propriety and economy. Those concepts have been revisited and redefined in order to reflect upon the domain itself by means of its own terminology, rather than imported concepts. This reflection, considered as a further study, would proceed towards solid and valid architectural theories corresponding the crisis of meaning and legitimacy.
A modified securtiy approach for web application used for the registration of the student at Çankaya University
(Çankaya Üniversitesi, 2014) Sosa, Ali Sami
This thesis goal is to design and implement a modified security approach for web-based system for student's registration in Natural and Applied Science Institute of Çankaya University Web application that help students to register by using the Internet..The employee can also use this application to track follow student status by monitoring the student information and give a report for each user, this proposed application can reduce time and effort for the users.The proposed application system can also be applied on smart devices (Iphone and Ipad)
A node authentication mechanism on wireless sensor networks
(2015) Ameen, Kameran Ali
A wireless sensor network (WSNs) is a network that consists of a large number of ultra-small autonomous devices which are resource-constrained called sensor nodes. Sensor networks may be deployed for a wide range of applications, including military sensing, environment monitoring and patient monitoring, etc. Sensors can collect, process and transmit data in a distributed and cooperative manner. They are usually deployed in an unattended environment (open area) and communicate with each other through wireless channels. Therefore, security is necessary to protect data from various types of attacks. The authentication process is one of the important ways to achieve security in WSNs. In this thesis, the pros of both symmetric and asymmetric key cryptography are used to achieve security. The proposed scheme secures communication by distributing the public key securely to both the base station and cluster head; as a result, this yields security of the message. The proposed scheme is efficient due to the application of data sequence over ECC, which in turn depends on the ECDLP. Therefore, it provides far more security and resistance against a number of attacks when compared with other existing schemes.
A prototype for assessment of information security awareness and implementation level
(2013) Kocamustafaoğulları, Meltem
Information is one of the most valuable assets for any organization and it should always be appropriately protected. Information security is the protection of information against threats to ensure the business continuity. Relying only on the technology is not sufficient and the human factor is the weakest cycle which needs to be strengthened for effective and sustainable information security management. Information security is not only related with technology but it is rather harmonization of people processes and technology. Organizations have the tendency to take action after security incident occurs instead of proactively. There is lack of awareness concerning the information security concepts and its necessity. Awareness and understanding at management level is utmost important to establish and maintain security culture in the organization. Organizations should be aware of information security aspects, understand their own security requirements and implement countermeasures accordingly. There are good practices and internationally accepted security standards such as ISO/IEC 27001 and ISO/IEC 27002 that can be taken as reference point and guidance. Organizations should establish and implement, sustain and improve information security management taking into account the proven good practices tailored for their own requirements. In this thesis it has been aimed; i. To provide a prototype model and tool for self assessment of information security awareness and implementation level of organizations, ii. To provide a tool to utilize as reference point for organization in building own security requirements and objectives as well as monitoring own overall progress, iii. To facilitate a self explanatory web-based tool addressing wide range of users without the need for prior training or in-depth technical knowledge on information security based on ISO/IEC 27001 and ISO/IEC 27002 international security standards and covering essential and common practice security topics, iv. To provide comparable values with other organizations who have similar information security requirements, v. To prepare tool in Turkish for contributing to improvement of information security awareness and implementation among organizations. The model is designed in eight sections for assessment of; IS Corporate Approach, Information Assets Security, Human Resources Security, Physical and Environmental Security, Communications and Information Systems Operations, Information Systems Access Control, Development and Maintenance Management, IS Incident Management and Business Continuity, IS Compliance and Monitoring Management. The tool is implemented in line with the designed model and tested by experts having solid professional background on information security as well as selective users in Turkey from various sectors such as finance, public authorities, consulting companies and education. The feedback and results verified that the objectives of the thesis are achieved and the tool can serve to improve information security awareness and implementation level of the target users with its web based, self explanatory and user friendly tool environment
A robust key management scheme for hierarchical wireless sensor networks
(2015) Al-Salihi, Aso Ahmed Majeed
Wireless Sensor Networks (WSNs) are used in many applications such as monitoring, target tracking and military applications, etc. A network is comprised of a large number of small, cheap, computational, limited energy devices which are called sensor nodes. These nodes are randomly deployed in open area to gather information. They communicate with each other via wireless media which are, however, vulnerable to being attacked by malicious nodes that may impersonate legitimate nodes. This makes the whole network liable to being hacked. Thus, security for WSNs is needed to keep any gathered data safe and to protect the communication links between sensor nodes. Key management plays a critical role in achieving security in a WSN. In this thesis, a robust key management scheme for hierarchical WSNs depends on, and exploits, the advantage of symmetric and asymmetric key cryptography. The proposed scheme uses the SHA-1 in HMAC not unlike a symmetric key for cluster formation and encryption of the private key via ECC, such as asymmetric key cryptography. Ultimately, the proposed scheme should be used to solve all these problems mentioned above.
A study on human capital index in closing the digital divide and raising e-government performance in middle east countries
(2015) Ahmed, Ali
E-government initiatives aim to employ information and communications technology (ICT) to provide better services to citizens and businesses while challenging the digital divide, which leads to closing the divide so as to promote e-government performance. This thesis takes related works already reported in the literature and addresses major factors that played a main role in achieving digitized governments, especially in the Middle East and Arab countries. As the case study, performance indices of Iraq, Bahrain and the KSA from 2002 to 2014 are studied in depth. The problem has been identified as the steady decline in the Human Capital Index (HCI) in the region. Therefore, the nature of the HCI measurement has been investigated. Major findings demonstrate a relationship between the HCI and ICT skills index of the International Telecommunication Union with a considerable digital divide in ICT skills in the Arab countries in addition to poor performance in the HCI. This finding is also supported by interpreting the differences between the indices of the HCI versus the telecommunication infrastructure index (TII) and online services index (OSI). This quick tool reveals that a poor HCI prevents these countries from promoting higher ranks. Another finding emerging from the statistics shows that the HCI exhibits unique behavior that differs from the TII and OSI and that it (the HCI) needs more time to improve. It is therefore necessary to focus on investing in HCI and ICT skills and to develop policies and strategies by those governments in charge. Among the limitations of this thesis are information sources that include only previous studies in addition to websites and in-situ surveys that were not conducted. The legal, economic and cultural aspects of the HCI are not studied. The HCI and ICT skills indices are found to play unique roles in closing the digital divide and this effect can be observed even in rich Arab countries not found in the list of world e-government leaders
A systematic review of interactive information retrieval evaluation studies, 2007-2016
(Çankaya Üniversitesi, 2017) Alyaseen, Haider Ali Hasan
Since the last mid-century researchers start investigate in the performance of IIR (interactive information retrieval). Many methods and measures were innovated and used in this field studies. To ensure the replication of maturation researches there are several factors that effect on the maturation of researches such as introducing standards for measurement and analysis, and understand past endeavors. In this study, we analyzed a vast range of papers within the period (2007-2016), where 1110 papers were examined manually and only 78 articles were included. Based on the achieved results in our study, we found that the researchers increased their concentration on IIR evaluation. Due this expansion of researching in this topic, we noticed that researches used some new techniques and datasets for evaluation of IIR systems. Most of the included papers were conducted based on the help of participants and questionnaires.
A Web-Based system to enhance students’ abilities in English education
(2015) Kother, Safaa Hadi
The research deals with enhancing the students' abilities to learn English language. The enhancement will be in the form of web-based computer system hosted in the root establishment of education that the students can access using their own computers at homes or school computers. The proposed system will use the computer digital media like movies, dictionaries, and speech facilities to simplify the reading, writing, listening, speaking and the vocabulary of the English language. The system is instructors' assistance system uses all attractive facilities to be students' favorite and beloved system and portable to give students the longest period of education with ability to share knowledge between them. It is an integrated multimedia system the override students motivations to enhance education facilities. The system will be implemented using the Microsoft Visual Studio development tool with aid of Visual C#.net integrated with Asp.Net tools to build the website according to the latest technologies in web-based application development. The designed system deals with analysis of the benefits of using it and questioners to show its intended application results and its abilities to reduce education costs and increase education effectiveness.
(alpha-psi) Type contractive mappings and related fixed point theorems
(2016) Ürgüp, Edanur
This thesis consists of three sections. The first section is reserved for introduction, some basic definitions and declaration of literature about alpha-psi type contractive mappings and related fixed point theorems have been presented. The second section deals with the main results. We have applied definition of alpha-admissible for two different functions of f and T. Furthermore, we have investigated their results. Finally, the third section includes discussion and conclusion.
An efficient energy scheme for hybrid clustering wireless sensor networks
(2015) Saleem, Ahmed M.
Kablosuz algılayıcı ağlarda kümeleme, enerji optimizasyonu için birçok uygulamalarda kullanılmakta olan önemli yöntemlerden biridir. Ağlarda birçok düğüm olduğundan, kümeleme yöntemleri ile uyarlanabilir enerji tüketimini sağlamak amaçlanmaktadır. LEACH rastgele kümelenme metoduna dayanan en popüler kümeleme algoritmalarından biridir. Bu algoritmada küme başı ve küme üyeleri olmak üzere iki farklı düğüm tipi bulunmaktadır. Ġletişim bu küme başları ile sağlanır. Bu nedenle LEACH algoritması, dinamik kümeleme ve uyarlanabilir enerji tüketimi sağlayarak ana amacına ulaşır. Bu tezde yeni bir melez kümeleme algoritması ağ alanında tanıtılmış, analiz edilmiş ve uygulanmıştır. Önerilen yöntemin enerji performansı LEACH (Düşük Enerji Uyarlanabilir Kümelenme Hiyerarşi) ve SEP (Stabil Seçim Protokolü) ile karşılaştırılmıştır. Farklı kısıtlamaları ve yöntemleri ile küme baş seçimi enerji tüketimi konusunda daha iyi sonuçlar ortaya çıkartır
An evaluation of three search engines (google, yahoo, bing) based on arabic user perception
(Çankaya Üniversitesi, 2017) Azeez, Suad Shatti
With the rapid increase of Arabic users around the world, a need of understanding the preferences of this wide Stratum of society is important. To do so we designed a questionnaire to evaluate three search engines (Google, Yahoo, and Bing) to reveal the Arabic user's perception of these three search engines. Each engine has its own features and it is own search methods to achieve the main purpose of search engines which is retrieving relevant results. This study exposes the pros and cons of the three tested search engines which give the opportunities to search engine developers to enhance their products. The results showed that Google performs very well comparing with Yahoo and Bing in some kind of data (text and video search) whereas image and advertisements Yahoo seems to be more accurate, Bing captivated many participants with its attractive homepage and useful features except supporting Arabic language in Bing map. Our results will help engineers and designers to improve their search engines in term of the design of homepages and result, improving their search engines algorithms for Arabic queries.
An investigation of electronic government transition case study in health: Hospitals in Erbil
(2013) Jamel, Ahmed Abdulrahman M.
Electronic government initiatives and public participation to them are among the indicators of today's development criteria of the countries. After consequent two wars, Iraq's current position in, for example, UN's e-government ranking is quite concerning and did not improve in recent years, either. In the preparation of this work, we are motivated with the fact that handling geographic data of the public facilities and resources are needed in most of the e-government projects; such examples are reported to the literature. Geographical information systems (GIS) provide most common tools not only to manage spatial data but also to integrate such type of data with nonspatial attributes of the features. With this background, this thesis proposes that establishing a working GIS in the health sector of Iraq would improve e-government applications. As the case study, investigating hospital locations in Erbil is chosen. The results show that setting up a GIS in Erbil does not require extreme technical knowledge; however, a strong limitation that obtaining clean and up-to-date data is an important concern. Although it is possible to establish a GIS in this sector, the starting point should not be acquiring hardware and software but to collect clean data from the field and to ensure that the data gets updated timely. Keywords: e-government, Iraq, Erbil, GIS, spatial data, hospital locations
Analysis of hybrid dynamical systems with an application in biological systems
(Çankaya Üniversitesi, 2017) Tahar, Noura A. Abdulrazaq
There are many complex dynamics appearing in nature science and technology one of the most useful approaches to model these phenomena is hybrid dynamical systems hybrid dynamic systems describe the interactions of continuous and discrete variables regulating each other ın this work we have looked at different types of hybrid systems that have been used in the modeling of biological systems we have also looked at the stability analysis of these systemsandhave given an example of a subclass of hybrid piecewise linear systems and checked the stability of these systems through an example
Analyzing digital image manipulation detection algorithms
(2015) Majeed, Sinan Nazar
In recent years tampering in digital image is becoming very widespread and more interesting. With powerful Image software, editing tools make a tampered image easy, thus the field of image forensic has become very important and crucial. In this thesis, investigation is made on the image by depending on the traces that occur when the soft correlation between rows and columns are divested in altered images, in term of linear dependency and exploitation of these traces in image forensic, depending on the properties of singular value decomposition and derived features which can be helpful and accurate sufficiently to reveal the tampering that is done on the genuine digital image.
Audio watermarking using DWT of second level decomposition of low frequency and using RMS on approximation coefficients
(Çankaya Üniversitesi, 2014) Maraha, Heyam Essam Jibrael
Digital media are distributed through the internet system in a magnificent manner due to the efficiency and inexpensiveness of such a system. Audio clips and other digital signals are transmitted, shared and used easily. This causes a real security problem. Solving this problem leads to finding authentication techniques to provide security for these digital media. Digital watermarking is a suggested solution technique to offer such security for these distributed digital signals. Digital watermarking is the art of embedding information (a watermark) in the original signal, taking into consideration preserving the quality of the host digital signal. There are different types of watermarking media such as image, video and audio; our thesis focuses on audio watermarking techniques. Also, there are a variety of techniques using the watermarking algorithm that depends on the type of algorithm that is used to embed the watermark in the original signal. In our thesis, we have used DWT (Discrete Wavelet Transform) of second level decomposition of the approximation coefficients of each frame. These frames are resulted from segmenting the original audio clips into frames, each one equal to 10 seconds. Also, we have applied the RMS (Root Mean Square) to these approximation coefficients which represent the low frequency of each frame. The aim of using the RMS is to find the higher magnitude approximation coefficients among the segmented frames; then to embed the watermark in a quarter of the selected frames according to the magnitude order. A watermark of 256 x 256 pixels was embedded in two tested audio clips (Pop and Classic) according to the former algorithm. We have applied 17 attacks that try to remove or modify the watermark that is hidden in the original audio clips. Also variety of models such as subjective and objective models were applied to evaluate the efficiency of the proposed algorithm results. The results of the proposed watermarking technique show an effective robustness against most of the applied attacks, especially in MP3 Compression, Quantization, Additive Noise, Resample and Low Pass Filter; however, it shows fragile robustness in Time Stretch and Pitch Shift attacks
Barriers and opportunities for e-commerce in Iraq: Perception of citizens
(2016) Hoshi, Alaa
The internet is a fashionable medium that both changes our lives and impact the behavior of Labor and consumer in both business and commerce. Several studies of e-commerce in developing countries have emphasized the barriers and opportunities of e-commerce associated with Information and communication Technology (ICT), regulatory environment, economic infrastructure and culture as most important factors of successful e-commerce. ICT has transformed the approach of many companies to conduct business around the globe, currently business is conducted online wider than traditional methods. Majority of the developing countries face limitations on the development of e-commerce, a numerous studies categorize the factors of e-commerce adoption in developing countries into two factors as external and internal factors. These factors are the main barriers for e-commerce adoption. While Middle-East is a fast growing and evolving region for e-commerce,e-commerce is still in its infancy in Iraq. Iraq's economy mostly relies on oil revenues and it is essential to diversify economic activity, e-commerce is one of the ways to realize this. Within this frame, the main aim of this research is to understand the barriers and opportunities of e-commerce and adoption level of e-commerce in Iraq as a developing country. In order to understand the main perceptional barriers of Iraqi citizens, a research was conducted with 110 participants. The findings of the research indicate that the most important barrier for e-commerce adoption in Iraq is related with Organizational, Governmental/ Legal and Financial Barriers. Due to the lack of comprehensive research for e-commerce in Iraq, this study will contribute to the literature with its findings related with barriers which form opportunities for e-commerce development.
Basin's fractal via complex newton's method
(2015) Murad, Zainab
In this thesis, we show that when we applied the Newton's method on the exponential function,f(z)=p(z)eQ(z) where p(z) and Q(z) are polynomials in the complex plane, the attraction basins of roots have finite area when n . With the help of MATLAB we obtained nice fractals in order to prove the finite basins area when n and infinite basins area when n<2
Binary image watermarking on audio signal using wavelet transform
(Çankaya Üniversitesi, 2014) Rashid, Rakan Saadallah
Digital watermarking approaches have recently become an important field of study in a number of practical applications. Generally, digital watermarking is the process of embedding particular information data into other signal data in such a way that the quality of the original information data is maintained. Watermarking can be performed on images, video, text, or audio to protect them from copyright violation. Among all of these types of watermarking, audio watermarking is difficult since the quality of such signals is highly affected by the watermark code. This thesis introduces some approaches that have features and may be applicable for audio watermarking. Generally, the digital audio watermarking approaches may be performed in either the special domain or the transform domain. The approaches that are based on the transform domain are gaining more attention due to their robustness or resistance to attackers. The most commonly used transforms for achieving digital audio watermarking are discrete cosine transform (DCT), short-term Fourier transform (STFT), and digital wavelet transform (DWT). In this research work, the main attention is paid toward digital wavelet transforms such as Haar and Daubechies-4. In addition, this thesis investigates the process of embedding a binary image into various audio signals such as speech and music signals. The values of the pixels in the binary images are either 1 or 0. These pixels are inserted into samples of the speech signal in such a way that the quality of the speech signal is preserved. One main reason to consider the audio watermarking approaches in the wavelet domain is that many modern multimedia standards such as JPEG2000 and MPEG-4 are based on the discrete wavelet transform. These common standards have brought new requirements such as low bit-rate transmission, coding, and many other advantages. Finally, experimental results are presented to validate the performance of the proposed watermarking approach and to compare its performance with other related watermarking approaches. The results show that the performance, in terms of signal-to-noise ratio (SNR) and normalized correlation (NC), of the proposed watermarking approach outperforms other approaches based on DCT. In addition, the results show that the extraction process of the hidden code becomes complex when considering any signal processing operations such as MP3 compression and high pass filtering. The worst case is when using a high pass filter where the recovered binary image is not satisfactory
Combined jpeg with dwt for image compression
(2012) Nabeel Dara, Omar
The main idea for this research is apply JPEG technique with enhanced quantization, on Discrete Wavelet Transformation (DWT). The DWT minimize the size of the image into convert the image into LL, HL, LH and HH sub-bands. The LL sub-band represents approximately original image, and then applied JPEG technique on the LL sub-band, then applied quantization to increase number of zeros. Finally apply Sequential Search Coding on the JPEG matrix for coding. The Sequential Search Coding work to convert group of data into single floating point value by using Key.

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