Bilgisayar Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/253
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Article Citation - WoS: 14Citation - Scopus: 18Existence Theory and Numerical Simulation of HIV-I Cure Model with New Fractional Derivative Possessing a Non-Singular Kernel(Springeropen, 2019) Aliyu, Aliyu Lsa; Alshomrani, Ali Saleh; Li, Yongjin; Inc, Mustafa; Baleanu, DumitruIn this research work, a mathematical model related to HIV-I cure infection therapy consisting of three populations is investigated from the fractional calculus viewpoint. Fractional version of the model under consideration has been proposed. The proposed model is examined by using the Atangana-Baleanu fractional operator in the Caputo sense (ABC). The theory of Picard-Lindelof has been employed to prove existence and uniqueness of the special solutions of the proposed fractional-order model. Further, it is also shown that the non-negative hyper-plane a positively invariant region for the underlying model. Finally, to analyze the results, some numerical simulations are carried out via a numerical technique recently devised for finding approximate solutions of fractional-order dynamical systems. Upon comparison of the numerical simulations, it has been demonstrated that the proposed fractional-order model is more accurate than its classical version. All the necessary computations have been performed using MATLAB R2018a with double precision arithmetic.Article Citation - WoS: 3Citation - Scopus: 5Block Size Analysis for Discrete Wavelet Watermarking and Embedding a Vector Image as a Watermark(Zarka Private Univ, 2019) Sever, Hayri; Sever, Hayri; Senol, Ahmet; Elbasi, Ersin; Bilgisayar MühendisliğiAs telecommunication and computer technologies proliferate, most data are stored and transferred in digital format. Content owners, therefore, are searching for new technologies to protect copyrighted products in digital form. Image watermarking emerged as a technique for protecting image copyrights. Early studies on image watermarking used the pixel domain whereas modern watermarking methods convert a pixel based image to another domain and embed a watermark in the transform domain. This study aims to use, Block Discrete Wavelet Transform (BDWT) as the transform domain for embedding and extracting watermarks. This study consists of 2 parts. The first part investigates the effect of dividing an image into non overlapping blocks and transforming each image block to a DWT domain, independently. Then, effect of block size on watermark success and, how it is related to block size, are analyzed. The second part investigates embedding a vector image logo as a watermark. Vector images consist of geometric objects such as lines, circles and splines. Unlike pixel-based images, vector images do not lose quality due to scaling. Vector watermarks deteriorate very easily if the watermarked image is processed, such as compression or filtering. Special care must be taken when the embedded watermark is a vector image, such as adjusting the watermark strength or distributing the watermark data into the image. The relative importance of watermark data must be taken into account. To the best of our knowledge this study is the first to use a vector image as a watermark embedded in a host image.Conference Object Citation - WoS: 3Citation - Scopus: 3Towards a Quest-Based Contextualization Process for Game-Based Learning(Acad Conferences Ltd, 2014) Yılmaz, Murat; Yilmaz, Murat; Saran, Murat; Saran, Murat; O'Connor, Rory; Yazılım Mühendisliği; Bilgisayar MühendisliğiThis study proposes a quest-based contextualization (QBC) process, which transforms part of a traditional lecture into a well-defined questing structure. The goal is to create a learning experience by using a systematic game-based questing approach. The QBC procedure is a set of sequential tasks defined by the game designer to reflect the instructional objectives of the course. It is formed as an interaction perspective from which a game system can be materialized, and which aims to improve the quality of the game flow and the user experience in a game-based learning environment. We claim that a game-based contextualization process can be used to restructure a traditional lecture in terms of educational quests. In particular, it was hypothesized that the design of such a quest-line should be constructed as a questing structure based on the chain of events, which are extracted from lecture notes. In the formulation of this design, the key events were discussed in an interview with an expert (i.e. content specialist) from a target field. This interview was transcribed, and further analyzed using an iterative qualitative approach as an interpretive analysis technique where an inductive proposition is considered for contextualization of data. This research used a thematic analysis methodology to explore the situations, which are suitable for questing and might be expandable into categories. Furthermore, questable points from the data were captured and situational elements and conversational key points were rigorously categorized. After building the initial mapping, we conducted a second interview with the same area expert to refine our preliminary findings. To evaluate our approach from the game design perspective, we sought advice from a small group of game design experts and practitioners who are recognized knowledgeable individuals in educational game development. Based on the opinion of four game design experts, the questing structure was revised and several game elements, such as extra battles, puzzles, and achievements, were added to support the elements of fun. Three of the experts argued that the proposed questing structure was highly educational, while the fourth claimed that such an improvement was partially important. These findings, while preliminary, suggested that a well-defined questing structure should be useful to improve the quality of a game-based learning environment.Article Citation - WoS: 42Citation - Scopus: 50Mobile Language Learning: Contribution of Multimedia Messages Via Mobile Phones in Consolidating Vocabulary(Springer Heidelberg, 2012) Saran, Murat; Saran, Murat; Seferoglu, Golge; Cagiltay, Kursat; Bilgisayar MühendisliğiThis study aimed at investigating the effectiveness of using multimedia messages via mobile phones in helping language learners in consolidating vocabulary. The study followed a pre-test/post-test quasi-experimental research design. The participants of this study were a group of students attending the English Preparatory School of an English-medium university in Turkey. Six different groups were formed in order to investigate the comparative effectiveness of supplementary vocabulary materials delivered through three different means: via mobile phones, on web pages, and in print form. The multimedia messages in this study included the definitions of words, exemplary sentences, related visual representations, information on word formation, and pronunciations of words. Analyses of the quantitative data showed that using mobile phones had positive effects on students' vocabulary acquisition. The results suggest that mobile phones offer great potential for providing learners with supplementary opportunities to recontextualize, recycle, and consolidate vocabulary.Article Citation - WoS: 6Citation - Scopus: 7Illicit Material Detection Using Dual-Energy X-Ray Images(Zarka Private Univ, 2016) Hassanpour, Reza; Hassanpour, Reza; Yazılım MühendisliğiDual energy X-ray inspection systems are widely used in security and controlling systems. The performance of these systems however, degrades with the poor performance of human operators. Computer vision based systems are of vital importance in improving the detection rate of illicit materials, while keeping false alarms at a reasonably low level. In this study, a novel method is proposed for detecting material overlapping and reconstructing multiple images by alleviating these overlaps. Evaluation tests were conducted on images taken from luggage inspection X-ray screening devices used in shopping centres. The experimental results indicate that the reconstructed images are much easier to inspect by human operators than the unprocessed original images.Article Citation - WoS: 25Citation - Scopus: 31Supporting Foreign Language Vocabulary Learning Through Multimedia Messages Via Mobile Phones(Hacettepe Univ, 2010) Saran, Murat; Saran, Murat; Seferoglu, Goelge; Bilgisayar MühendisliğiThis study explored the effectiveness of mobile learning in foreign language education. With this purpose, instructional materials to be delivered through mobile phones operated in second generation GSM technology in order to improve English language learners' vocabulary acquisition were developed. The multimedia messages in this study allowed students to see the definitions of words, example sentences, related visual representations, and pronunciations. After students finished reading multimedia messages, interactive short message service (SMS) quizzes for testing their learning were sent. In addition, the study examined students' tendencies in using MMS in their second language vocabulary study and explored the opinions of the students toward the use of mobile phones for instructional purposes. The findings of this study suggest some important points to consider while creating MMS content and a SMS quiz system for educational purposes.Conference Object Real Time Hand-Face Tracking Using Skin Color and Motion(int inst informatics & Systemics, 2005) Hassanpour, Reza; Hassanpour, Reza; Birdal, Ahmet; Yazılım MühendisliğiHuman hand gestures and face expressions are a major tool for communicating ideas between people. Hand gestures may also account for the main part of the communication when other tools are not preferred or simply not available. First step for an automatic interpretation of these gestures and expressions is their segmentation and tracking. We have developed an algorithm to track hand motions in real time. Our algorithm is based on the motion and color features of the interested areas. A modified form of Adaptive Mean Shift method is used for tracking hands and face. A rule based system monitors the correctness of the segmentation and tracking.Conference Object Camera Auto-Calibration Using a Sequence of 2d Images With Small Rotations and Translations(Crc Press-taylor & Francis Group, 2003) Hassanpour, Reza; Hassanpour, R; Atalay, V; Yazılım Mühendisliği3D model generation needs depth information of the object in the input images. This information can be found using stereo imaging but it needs camera parameters. Camera calibration is not possible without some knowledge about the objects in the scene or assuming fixed or known values for the camera parameters. When using fixed camera parameters, however, small rotation angles or small translation in camera position can degenerate the results. The degeneracy can be omitted by adding new restrictions to the a-priori knowledge about the camera parameters. The calibrated data may be used to reconstruct 3D model of the scene.Editorial Citation - WoS: 3Citation - Scopus: 4Improving Social Aspects of the Software Development Process: Games, Gamification and Related Approaches(Graz Univ Technolgoy, inst information Systems Computer Media-iicm, 2016) Yilmaz, Murat; Yılmaz, Murat; O'Connor, Rory V.; Mora, Manuel; O’Connor, Rory V.; Yazılım MühendisliğiConference Object Citation - WoS: 1Information/Knowledge Society and Europe(World Acad Sci, Eng & Tech-waset, 2005) Aktaş, Ahmet Ziya; Aktas, A. Ziya; Bilgisayar MühendisliğiDuring the last decade some long lasting changes and developments are shaping the global society. The world is entering a new society which is already named as information or knowledge society. In the paper, information/knowledge society is elaborated first. Starting in the year 2000, European Union has initiated some special projects such as eEurope and eEurope+ and activities such as Bologna Process and Socrates/Erasmus Program. The paper will review these activites in relation with information or knowledge society. Before paper ends with a conclusion, some views relevant to the topic are also presented.