Bilgisayar Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/253
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Conference Object Perceptions, Expectations and Implementations of Big Data in Public Sector(IEEE, 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.Conference Object Energy dissipation characteristics of Wireless Sensor Networks with unidirectional links(IEEE, 2012) Tanyer Özyer, Sibel; Tavlı, Bülent; Koyuncu, MuratLink unidirectionality is a commonly encountered phenomena in Wireless Sensor Networks (WSNs), which is a natural result of various properties of wireless transceivers as well as the environment. Transmission power heterogeneity is the dominant factor that creates unidirectional links. In this study, we investigate the impact of transmission power heterogeneity on the lifetime of WSNs through a novel Linear Programming (LP) framework both for networks that utilize only bidirectional links and for those that can use bidirectional links as well as unidirectional links. Our results show that transmission power heterogeneity can lead to more than 25 % decrease in network lifetime for networks that utilize only bidirectional links when compared to a network without any heterogeneity. However, if the use of unidirectional links is also enabled then, the decrease in network lifetime is at most 12 %.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.Publication Stereo vision and statistical based behaviour prediction of driver(IEEE, 2007) Eren, Haluk; Çelik, Ümit; Poyraz, MustafaThe goal of this project is to develop a webeam-based system for monitoring the activities of automobile drivers. As in any system deployed for monitoring driver activities, the primary goal is to distinguish between safe and unsafe driving actions. There is no fixed list of actions that qualifies the unsafe driving behaviors. In general, an activity or an action that reduces a driver's alertness of their surroundings should be classified as unsafe driving behavior. Some examples of unsafe driving behavior include fatigue, talking on a cellular telephone, eating, and adjusting the controls of the dashboard stereo while driving. In this study, we also investigated the relationship between 2D and 3D face and pose recognition.Publication Evaluation of 3D high resolution images using inexpensive distributed parallel system: Application fields on medical images(IEEE, 2007) Eren, Hüseyin; Çelik, Ümit; Poyraz, MustafaIn the telesurgery operations, images should be high resolution and processed in real time. It seems difficult to accomplish this process in real time using only one computer. In our study, we propose to get 3d scene images inside and outside of surgery environment in real time and transfer them into different places. As known, 3d reconstruction needs intensive calculations. Nowadays, using distributed parallel systems are getting increase. Therefore, we investigate the performance rates using a group of inexpensive inert computers which work as a distributed parallel system supposed to be established in a medical environment.Publication Optimal energy efficient routing in Wireless Sensor Networks with link asymmetry(IEEE, 2012) Özyer, Sibel T.; Tavlı, Bülent; Koyuncu, MuratIn Wireless Sensor Networks (WSNs), link unidirectionality is an unavoidable phenomenon. The existence of unidirectional links can be attributed to several physical factors induced by the transceiver characteristics as well as other environmental phenomena. Transmission power heterogeneity is the dominant paradigm that leads to unidirectionality. In this study, we investigate the effects of transmission power heterogeneity on the lifetime of WSNs through a novel Linear Programming (LP) framework both for networks that utilize only bidirectional links and for those that can use unidirectional links in addition to bidirectional links. Our results show that transmission power heterogeneity can lead to more than 25 % decrease in network lifetime for protocols that can operate only on bidirectional links when compared to a network without any heterogeneity. However, if the use of unidirectional links is also enabled then, the decrease in network lifetime is at most 12 %.Publication Digital Video Stabilization Using Radon Transform(IEEE, 2012) Babagholami-Mohamadabadi, Behnam; Bagheri-Khaligh, Ali; Hassanpour, RezaDigital video stabilization is a category of techniques used to reduce the impact of unintentional camera motion such as jitter, jiggle, and other unsteady motions. These unintentional shakings degrade visual quality of videos and reduce the performance of subsequent processes such as video compression. Digital video stabilization which is performed by post processing the acquired frames, suffers from inaccuracy of motion estimation which is mostly due to the local motions of internal moving objects included in videos, and long processing time which prohibits them from being used in real time applications. In this paper we propose a fast and accurate transform based motion estimation method which is robust to internal moving objects. Our experimental results with real and synthesized data indicate efficacy of our proposed method.Publication About nanometer sized analogues of basic electronic and optical components(IEEE, 2008) Quandt, Alexander; Özdoğan, Cem; Ferrari, Maurizio; Speranza, GiorgioWe discuss a downsizing of optical components into the nanometer range. It presupposes the substitution of photons by ballistic electrons, but it also requires a simple and robust concept to assemble the analogues of basic electronic and optical components on such a tiny length scale. Here, one of the most promising candidate schemes employs graphene as a basic nanosubstrate. We elucidate the suggested behaviour of graphene as an electronic metamaterial [1], and show that other desired electronic or optical functionalities may be obtained through a patterning with sub-nanometer sized boron clusters [2].Conference Object SpEnD portal: linked data discovery using SPARQL endpoints(IEEE, 2017) Yumuşak, Semih; Aras, Rıza Emre; Uysal, Elif; Doğdu, Erdoğan; Kodaz, Halife; Öztoprak, KasımWe present the project SpEnD, a complete SPARQL endpoint discovery and analysis portal. In a previous study, the SPARQL endpoint discovery and analysis steps of the SpEnD system were explained in detail. In the SpEnD portal, the SPARQL endpoints are extracted from the web by using web crawling techniques, monitored and analyzed by live querying the endpoints systematically. After many sustainability improvements in the SpEnD project, the SpEnD system is now online as a portal. SpEnD portal currently serves 1487 SPARQL endpoints, out of which 911 endpoints are uniquely found by SpEnD only when compared to the other existing SPARQL endpoint repositories. In this portal, the analytic results and the content information are shared for every SPARQL endpoint. The endpoints stored in the repository are monitored and updated continuously.Book Part Parallelization of sparsity-driven change detection method(IEEE, 2017) Özgür, Atilla; Saran, Ayşe Nurdan; Nar, FatihIn this study, Sparsity-driven Change Detection (SDCD) method, which has been proposed for detecting changes in multitemporal synthetic aperture radar (SAR) images, is parallelized to reduce the execution time. Parallelization of the SDCD is realized using OpenMP on CPU and CUDA on GPU. Execution speed of the parallelized SDCD is shown on real-world SAR images. Our experimental results show that the computation time of the parallel implementation brings significant speed-ups.