Bilgisayar Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/253
Browse
Browsing Bilgisayar Mühendisliği Bölümü Yayın Koleksiyonu by Department "Çankaya Üniversitesi, Mühendislik Fakültesi, Bilgisayar Mühendisliği Bölümü"
Now showing 1 - 20 of 61
- Results Per Page
- Sort Options
Article Face Photograph Recognition via Generation from Sketches using Convolutional Neural Networks(2019) Karasolak, Mustafa; Choupani, RoyaFace photo-sketch matching is an important problem for law enforcement agencies in terms of identifying suspects. In this study, a new sketch-photo generation and recognition technique is proposed by using residual convolutional neural network architecture. The suggested RCNN architecture consists of 6 convolutions, 6 ReLU, 4 poolings, 2 deconvolution layers. The proposed architecture is trained with face photos and sketches. Sketches are supplied as an input to the RCNN architecture and, generated face photos are obtained as the output. Then, the generated face photos are compared with the photos of the people in the database. Structural Similarity Index (SSIM) is used to measure the pairwise similarity and the photo with the highest index score is matched. CUHK Face Sketch Database containing 188 images is tested. In the experiments, 148, 20, and 20 images are used for training, validation, and testing, respectively. Data augmentation applied to 148 training images produced 444 images. Experimental results show that the success of the training curve is 90.55% and the validation success is 91.1%. True face recognition success from generated face images with SSIM is 93.89% for CUHK Face Sketch database (CUFS) and 84.55% AR database.Conference Object Softare Vulnerability Prediction using Extreme Learning Machines Algorithm(2019) Keçeli, Ali Seydi; Kaya, Aydın; Çatal, Çağatay; Tekinerdoğan, BedirSoftware vulnerability prediction aims to detect vulnerabilities in the source code before the software is deployed into the operational environment. The accurate prediction of vulnerabilities helps to allocate more testing resources to the vulnerability-prone modules. From the machine learning perspective, this problem is a binary classification task which classifies software modules into vulnerability-prone and non-vulnerability-prone categories. Several machine learning models have been built for addressing the software vulnerability prediction problem, but the performance of the state-of-the-art models is not yet at an acceptable level. In this study, we aim to improve the performance of software vulnerability prediction models by using Extreme Learning Machines (ELM) algorithms which have not been investigated for this problem. Before we apply ELM algorithms for selected three public datasets, we use data balancing algorithms to balance the data points which belong to two classes. We discuss our initial experimental results and provide the lessons learned. In particular, we observed that ELM algorithms have a high potential to be used for addressing the software vulnerability prediction problem.Publication Production and retrieval off rough classes in multi relations(IEEE Computer Soc, 2007) Tolun, Mehmet R.; Sever, Hayri; Görür, Abdül KadirOrganizational memory in today's business world forms basis for organizational learning, which is the ability of an organization to gain insight and understanding from experience through experimentation, observation, analysis, and a willingness to examine both successes and failures. This basically requires consideration of different aspects of knowledge that may reside on top of a conventional information management system. Of them, representation, retrieval and production issues of meta patterns constitute to the main theme of this article. Particularly we are interested in a formal approach to handle rough concepts. We utilize rough classifiers to propose a preliminary framework based on minimal term sets with p-norms to extract meta patterns. We describe a relational rule induction approach, which is called rila. Experimental results are provided on the mutagenesis, and the KDD Cup 2001 genes data sets.Publication Clustering Analysis for Vasculitic Diseases(Springer-Verlag Berlin, 2010) Yıldırım, Pınar; Çeken, Çınar; Çeken, Kağan; Tolun, Mehmet R.We introduce knowledge discovery for vasculitic diseases in this paper. Vasculitic diseases affect some organs and tissues and diagnosing can be quite difficult. Biomedical literature can contain hidden and useful knowledge for biomedical research and we develop a study based on co-occurrence analysis by using the articles in MEDLINE which is a widely used database. The mostly seen vasculitic diseases are selected to explore hidden patterns. We select PolySearch system as a web based biomedical text mining tool to find organs and tissues in the articles and create two separate datasets with their frequencies for each disease. After forming these datasets, we apply hierarchical clustering analysis to find similarities between the diseases. Clustering analysis reveals some similarities between diseases. We think that the results of clustered diseases positively affect on the medical research of vasculitic diseases especially during the diagnosis and certain similarities can provide different views to medical specialists.Article Structural stability and energetics of single-walled carbon nanotubes under uniaxial strain(2003) Dereli, G.; Özdoğan, CemA (10x10) single-walled carbon nanotube consisting of 400 atoms with 20 layers is simulated under tensile loading using our developed O(N) parallel tight-binding molecular-dynamics algorithms. It is observed that the simulated carbon nanotube is able to carry the strain up to 122% of the relaxed tube length in elongation and up to 93% for compression. Young's modulus, tensile strength, and the Poisson ratio are calculated and the values found are 0.311 TPa, 4.92 GPa, and 0.287, respectively. The stress-strain curve is obtained. The elastic limit is observed at a strain rate of 0.09 while the breaking point is at 0.23. The frequency of vibration for the pristine (10x10) carbon nanotube in the radial direction is 4.71x10(3) GHz and it is sensitive to the strain rate.Conference Object Perceptions, Expectations and Implementations of Big Data in Public Sector(2018) Doğdu, Erdoğan; Özbayoğlu, Murat; Yazıcı, Ali; Karakaya, ZiyaBig Data is one of the most commonly encountered buzzwords among IT professionals nowadays. Technological advancements in data acquisition, storage, telecommunications, embedded systems and sensor technologies resulted in huge inflows of streaming data coming from variety of sources, ranging from financial streaming data to social media tweets, or wearable health gadgets to drone flight logs. The processing and analysis of such data is a difficult task, but as appointed by many IT experts, it is crucial to have a Big Data Implementation plan in today’s challenging industry standards. In this study, we performed a survey among IT professionals working in the public sector and tried to address some of their implementation issues and their perception of Big Data today and their expectations about how the industry will evolve. The results indicate that most of the public sector professionals are aware of the current Big Data requirements, embrace the Big Data challenge and are optimistic about the future.Article Mobile Assisted Language Learning: English Pronunciation at Learners' Fingertips(Anı Yayıncılık, 2009) Saran, Murat; Seferoğlu, Gölge; Çağıltay, KürşatProblem Statement: The study of pronunciation had been a relatively neglected issue in the foreign/second language acquisition literature. Likewise, in classroom contexts, pronunciation has received less attention as compared to the other language components and skills with the belief that it is peripheral to successful communication. Yet, there is a recent revival of interest in pronunciation research. The literature on foreign/second language acquisition highlights that in general in-class activities are not sufficient for effective language learning and that learners should also have input and output opportunities outside the classroom. This holds true for learning pronunciation as the literature suggests that just classroom instruction has a negligible impact on oral production of learners. With their widespread use and their features such as mobility, localization, and personalization, mobile phones offer a great potential for out-of-class learning. Yet, there is scarce research on the use of mobile phones in language learning contexts nor any on using mobile phones to improve learners' pronunciation. This study is aimed to make a significant contribution to the literature in these respects. Purpose of the Study: The major aim of this study was to investigate the potentials and effectiveness of using mobile phones in foreign language education. In particular, the effects of using multimedia messages via mobile phones for improving language learners' pronunciation of words were explored. Methods: A mixed method approach involving both quantitative and qualitative components was employed in this study. The quantitative part of the study followed a pre-test/post-test quasi-experimental design. The qualitative part of the study included post-study semi-structured interviews with the students, and a questionnaire involving open ended items. The participants of this study were a group of students attending the English Preparatory School of an English-medium university in Turkey. There different groups were formed in order to investigate the comparative effectiveness of supplementary materials delivered through 3 different means: mobile phones, web pages, and handouts. Results: Analyses of the quantitative data showed that using mobile phones had positive effects on students' pronunciation learning. The qualitative data collected through the questionnaire and the interviews supported this finding. All participants provided positive feedback about the mobile learning application used in this study. Conclusions and Recommendations: This study extends the use of use mobile phones, which are already in use for communication and entertainment, to educational settings. The findings of the study pose crucial implications for foreign language teaching and learningArticle The impact of feature types, classifiers, and data balancing techniques on software vulnerability prediction models(2019) Kaya, Aydın; Keçeli, Ali Seydi; Çatal, Çağatay; Tekinerdoğan, BedirSoftware vulnerabilities form an increasing security risk for software systems, that might be exploited to attack and harm the system. Some of the security vulnerabilities can be detected by static analysis tools and penetration testing, but usually, these suffer from relatively high false positive rates. Software vulnerability prediction (SVP) models can be used to categorize software components into vulnerable and neutral components before the software testing phase and likewise increase the efficiency and effectiveness of the overall verification process. The performance of a vulnerability prediction model is usually affected by the adopted classification algorithm, the adopted features, and data balancing approaches. In this study, we empirically investigate the effect of these factors on the performance of SVP models. Our experiments consist of four data balancing methods, seven classification algorithms, and three feature types. The experimental results show that data balancing methods are effective for highly unbalanced datasets, text-based features are more useful, and ensemble-based classifiers provide mostly better results. For smaller datasets, Random Forest algorithm provides the best performance and for the larger datasets, RusboostTree achieves better performance.Book Part Büyük Veri Mahremiyeti ve Güvenliği(Grafiker Yayınları, 2017) Saran, Ayşe NurdanBilim geliştikçe teknolojiler gelişmekte ve yeni teknolojilerde bilimin daha da gelişmesine ve bilinmezleri daha iyi anlamamıza, yeni çalışmalar yapmamıza en önemlisi çevremizi ve dünyamızı daha iyi anlamamızı kolaylaştırmaktadır. Son yıllarda “büyük veri”, “veri bilimi”, “açık veri” “büyük veri analitiği”, “bilgi ekonomisi” gibi başlıklar ülkemizde de pek çok etkinlikte tartışılmakta, çözümler geliştirilmeye çalışılmakta ve iyi örnekler oluşturulmaya çalışılmaktadır. Bu kitabın ülkemizde açık veri ve büyük veri analitiği, güvenliği ve mahremiyetinin gelişmesine katkılar sağlaması beklenmektedir. Verilerin günümüzün altın rezervleri olduğunun bilinciyle çalışmalar yapılmalıdır.Conference Object Towards a Serious Game to Teach ISO/IEC 12207 Software Lifecycle Process: An interactive learning approach(2015) Aydan, Ufuk; Yılmaz, Murat; O’Connor, Rory V.ISO/IEC 12207 training is a key element to provide an ability to software development organizations for selecting a set of required processes, measuring the performance of these processes, and continuously improving them. Traditionally, such training is either performed by an expert individual to the software quality management personnel most likely in form of a seminar in a classroom environment. This may also be given by a suitability qualified professional, such as a registered auditor. However, software requirements are usually subject to change, and therefore such training is not enough to teach the substantial details of the entire standard. This has led to increased reports of complications, which demotivates organization to use this standard. To improve the quality of training, a 3D serious game was proposed for the software practitioners. The preliminary idea here is that the game employs 3D office landscape to provide a realistic virtual environment ensuring that the training will be based on real word like situations. Before building a prototype for our serious game, we consulted five industrial experts whose works are related with ISO standards. To give these practitioners an opportunity to explore the conceptual design and raise some potential problems, the semi-structured interview method was used. Based on the suggestions of experts, dynamics and mechanics of the proposed game were updated. Taken together, initial results suggest that a serious game for teaching ISO/IEC 12207 should be useful for individuals who are interested to learn more about the standard.Article İmge İçine Bilgi Gizlemede Kullanılan LSB Yöntemlerinin Karşılaştırması(2013) Saran, Nurdan; Olcay, CemDijital imgeleri temel olarak kayıplı sıkı¸stırılmı¸s tipte olanlar, sıkı¸stırılmamı¸slar ve kayıpsız sıkı¸stırılmı¸slar olarak ¨u¸ce ayırabiliriz. Sıkı¸stırılmamı¸s ve kayıpsız sıkı¸stırılmı¸s imgelerde bilgi gizlemek i¸cin en ¸cok kullanılan y¨ontem, imgenin son bitlerinin mesajın bitleri ile de˘gi¸stirilmesi y¨ontemidir. Son bitlerin de˘gi¸simi genellikle imgede g¨ozle g¨or¨ulebilir bir de˘gi¸sikli˘ge sebep olmamaktadır. Ort¨u imgedeki piksellerin son bitlerinin de˘gi¸simi ile ¨ veri gizleme y¨ontemlerini her renk kanalında 1 bit yada daha fazla veri gizleyenler ve birden ¸cok renk kanalında renk kanalı sayısından daha az miktarda veri gizleyenler olarak ikiye ayırabiliriz. Bu ¸calı¸smada en ¨onemsiz bite (least significant bit-LSB) gizleme y¨ontemlerinden yer de˘gi¸stirme [1], e¸sle¸stirme [2], e¸sle¸stirmenin geli¸stirilmi¸s bir hali olan Chan’ın algoritması [3], 2/3 verimli g¨omme [4], Hamming kodlarını kullanılarakArticle Cassandra ve MongoDB NoSQL Veri Tabanlarının Karşılaştırmalı Güvenlik Analizi(2019) Saran, Murat; Saran, NurdanIn this study, we analyze the security of two NoSQL databases, MongoDB 3.6.3 and Cassandra 3.11.1 in a multi-node configuration in two steps. The first step is a comparative study of both databases’ security features according to ten selected criteria from the literature. The second step is analyzing data encryption overhead using the Yahoo Cloud Serving Benchmark tool. This study will help decision-makers and researchers to realize the most crucial security features concerning NoSQL databases as well as to be able to analyze the NoSQL databases regarding the security features. Our security comparison results show that both databases have noteworthy security features. However, Cassandra takes the lead as it supports more security criteria. Besides, the encryption/decryption performance of the MongoDB business version is 53% faster than the Cassandra business version, and the average amount of data that the MongoDB business version can process per minute is 45% higher than the Cassandra business version. This result shows that it is more appropriate to use MongoDB in environments where encryption is required.Conference Object Metinden Bağımsız Otomatik Konuşmacı Tanıma Sistemleri ve Performans Karşılaştırması(2010) Taşel, Faris Serdar; Sönmez, Arzu BurçakOtomatik Konuşmacı Tanıma Sistemleri önemli bir çalışma alanı olmakla beraber başlıca üç farklı alanda yaygın olarak kullanılmaktadır. Bunlar, kimlik doğrulama, kimlik izleme ve adli uygulamalardır. Otomatik konuşmacı tanıma uygulamaları, konuşma esnasında çıkardığımız seslerden gerekli bilgilerin çıkartılması esasına dayanmaktadır. Geliştirilen uygulamalar, çıkarılan bu bilgiler doğrultusunda, insanları seslerinden tanımaları için eğitilebilirler. Otomatik Konuşmacı Tanıma Sistemlerinde ilk basamak öznitelik çıkarma işlemidir. Bu işlem için MFCC (Mel-frequency Cepstral Coefficients) tabanlı yaklaşımlar yaygın olarak kullanılır. İkinci basamak ise öznitelik sınıflandırma işlemidir. Her konuşmacı bir sınıfa karşılık gelmekte ve bulunduğu sınıfın özelliklerini belirlemektedir. VQ (Vector Quantization - Vektörel Nicemleme) ve GMM (Gaussian Mixture Models - Gaussian Karışım Modelleri), sınıflandırma işleminde kullanılan tekniklerden en yaygın olanlarıdır. Bahsettiğimiz bu işlemler sistemin eğitim safhasında kullanılırlar. Test safhasında ise, herhangi bir kişiden gelen ses bilgisinin eğitim safhasında oluşturulan sınıflardan hangisine ait olabileceğine karar verilir. Kapalı küme sistemlerde, sistem sadece daha önce eğitilmiş konuşmacı sınıflarını ayırdetmekten sorumludur. Bu çalışma, metinden bağımsız, kapalı küme konuşmacı tanıma sistemi geliştirmede etkili olan bu iki tekniği performans açısından karşılaştırmak amacıyla yapılmıştır. Elde edilen sonuçlarda GMM tekniğinin, VQ tekniğinden daha başarılı olduğu gözlemlenmiştir.Conference Object Article An Exploratory Study to Assess Digital Map Zoom/Pan/Rotate Methods with HoloLens(2018) Kılınç, İsmail; Yılmaz, MuratGeographical map display plays an important part of a GIS (GeographicalInformation System). The usability of a map display is certainly depends on how easilyuser navigates through spatial data and selects features on it. Currently, desktop computerbased GIS applications uses mouse movements, buttons and scroll for a set of functionssuch as zoom, pan and rotate. However currently Hololens supports only gaze, air tapgesture and voice commands as an input. Although the functionality looks simple, it ischallenging to find optimal solution by using input devices for those functions even whilecreating in a desktop application. This study aims to assess an optimal way to enable thesefunctions on hologram maps by investigating its validity and usability.Article Üç yazılım firmasında yazılım süreç değişimlerinin gözlenen etkileri: Endüstriyel keşif vaka çalışması(2019) Yılmaz, MuratYazılım geliştirme süreçleri, gelişen yeni teknolojiler ve onun sağladığı imkânlar doğrultusunda sürekli iyileştirme gerektirir. Yazılım müşterilerinin pazarlanabilir fonksiyonlar içeren ürün talepleri üzerine kurgulanmış yeni nesil yazılım geliştirme modelleri ara ürün üretim hızını ve dolayısıyla ara sürüm sayısını arttırmayı hedeflemektedir. Bu ihtiyaçlar ışığında, yazılım şirketlerinin geliştirme süreçlerini müşteriden gelen istekleri karşılamak adına gözden geçirmeleri gerekmektedir. Ancak, daha da önemlisi, şirketler yazılım üretim hattındaki verimi düşürmemek için süreçlerini yenilikçi pratikler doğrultusunda değiştirmek zorunda kalmaktadırlar. Bu makalede, yazılım geliştiren üç şirketin yazılım geliştirme yöntemleri durum çalışması yöntemi ile detaylı olarak incelenerek, süreç değişimi aktiviteleri sistematik bir şekilde detaylandırılmıştır. Elde edilen bilgiler ışığında, üç firmanın da yazılım geliştirme yöntemlerindeki değişimler sorgulanarak edindikleri tecrübeler ve bu edinimlerin süreçler üzerindeki etkileri tartışılmıştır. Çalışmanın sonucunda, yazılım ürün geliştirme başarısının sürecin iyi işletilmesini önemli bir oranda etkilediği, yazılım geliştiren takımların da edindikleri kazanımlar ışığında kendi süreçlerini tasarlamaya çalıştıkları gözlenmiştir.Article Remote and Autonomous Controlled Robotic Car based on Arduino with Real Time Obstacle Detection and Avoidance(2019) Yılmaz, Esra; Tarıyan Özyer, SibelIn robotic car, real time obstacle detection and obstacle avoidance are significant issues. In this study, design and implementation of a robotic car have been presented with regards to hardware, software and communication environments with real time obstacle detection and obstacle avoidance. Arduino platform, android application and Bluetooth technology have been used to implementation of the system. In this paper, robotic car design and application with using sensor programming on a platform has been presented. This robotic device has been developed with the interaction of Android-based device. Arduino Uno has been used as the robot's brain. The robot has many hardware components such as Bluetooth module, PIR sensor, ultrasonic sensor, and buzzers. It also consists of the software component that uses a mobile application. The desired direction or mode by mobile application can be selected by the user of the robotic car to control the movement of the car. The user can control the robot movements from his/her own intelligent device or take the robot in automatic mode and let the car drive its own way. Thus, the robot can flee from the obstacle and also detect live objects. The purpose of this article is to alert the civilian and military personnel to potential terrorist attacks especially in military areas with live detectable sensors.Conference Object Publication Approaches on the selection of web cameras and calibration targets for stereo vision(IEEE, 2006) Eren, Hüseyin; Çelik, Ümit; Poyraz, MustafaIn this paper, it is studied on the calibration by using specified web cameras. The performance of 3D computer vision depends on the accuracy of camera parameters. Therefore, camera calibration is very crucial in stereo vision. In this study, the options and selection of the target object that is used by the process of camera calibration are reviewed and evaluated some results obtained by web cameras. Webcams' costs are low relatively to the other digital consumer cameras but cannot be acquired a high resolution image.Article Implementation of the Human Resources Information Systems and Comparative Study of Various Platforms(2016) Abdulhakeem Majeed, Zubaidah; Tarıyan Özyer, SibelWe are living in an epoch of changes during which highly competitive advantages are always required for quick and effective reactions in any organization. It is expected that the rate of change will increase greatly in the upcoming future along with the high development rate of new technologies. Today’s businesses need either to adapt to these changes or be more innovative to meet these new necessities. In this research, the Human Resources Management (HRM) has been aim to study and especially Human Resources Information System (HRIS) has been studied. In addition, the benefits and constraints of the implementation of a Human Resources Information System (HRIS) on an institution have been discussed in this study. Moreover, HRIS open source software platforms have been investigated and comparative study has been proposed. Selected open source software platform has been designed to implement HRIS to the University of Kirkuk
