Browsing by Author "Maraş, Hadi Hakan"

Now showing 1 - 7 of 7

CBS Tabanlı Suç Analizi Yöntemleri
(2013) Özçetin, M.; Maraş, Hadi Hakan; 34410; 06.01. Bilgisayar Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Coğrafi Bilgi Sistemleri (CBS) günlük hayatımızda önemi sürekli olarak artan uygulamalara sahiptir. CBS’nin popüler ve kritik uygulama alanlarından biri de mekânsal suç analizidir. Günümüzde suç oranları artış göstermekte ve bu yüzden suç eğilimlerini analiz etmek ve suçu önleyici tedbirler almak büyük önem arz etmektedir. Suçlar çoğu zaman mekânsal ve zamansal modeller göstermektedir. Örneğin, bazı suç türleri bazı lokasyonlarda nispeten yüksek oranlarda işlenebilmektedir. Bazıları ise gün içinde belli saat aralıklarında yüksek oranlarda olabilmektedir. Klasik suç analiz yöntemlerine coğrafi destek eklemek, tablosal veya istatistiksel metotların sunamayacağı son derece önemli ve müstesna faydalar sağlayabilir. Örneğin, belli bir suç türünün mekânsal dağılımını görmek veya farklı suç türlerinin lokasyonlarını harita üzerinde karşılaştırmak, karar verme pozisyonundaki yöneticilere kritik ve önemli ipuçları verebilir. Bu yüzden, suç analiz yöntemlerine mekânsal boyut katmak emniyet birimlerindeki çalışmalara önemli bir destek sağlamaktadır
Covariance Features for Trajectory Analysis
(Kaunas Univ Technology, 2018) Karadeniz, Talha; Maraş, Hadi Hakan; 304886; 34410; 06.09. Yazılım Mühendisliği; 06.01. Bilgisayar Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
In this work, it is demonstrated that covariance estimator methods can be used for trajectory classification. It is shown that, features obtained via shrunk covariance estimation are suitable for describing trajectories. Compared to Dynamic Time Warping, application of explained technique is faster and yields more accurate results. An improvement of Dynamic Time Warping based on counting statistical comparison of base distance measures is also achieved. Results on Australian Sign Language and Character Trajectories datasets are reported. Experiment realizations imply feasibility through covariance attributes on time series.
Did satellite imagery supersede aerial imagery? A perspective from 3D geopositioning accuracy
(2016) Yilmaz, Altan; Erdogan, Mustafa; Maraş, Hadi Hakan; Aktuğ, Bahadır; Maraş, Süleyman Sırrı; 34410; 06.01. Bilgisayar Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
In this study, the geometric accuracy comparison of aerial photos and WorldView-2 satellite stereo image data is evaluated with the different number and the distribution of the ground control points (GCPs) on the basis of large scale map production. Also, the current situation of rivalry between airborne and satelliteborne imagery was mentioned. The geometric accuracy of Microsoft UltraCam X 45 cm ground sampling distance (GSD) aerial imagery and WorldView-2 data both with and without GCPs are also separately analyzed. The aerial photos without any GCP by only using global navigation satellite system (GNSS) and inertial measurement unit (IMU) data with tie points give an accuracy of +/- 1.17 m in planimetry and +/- 0.71 m in vertical that means nearly two times better accuracy than the rational polynomial coefficient (RPC) of stereo WorldView-2. Using one GCP affects the accuracies of aerial photos and WorldView-2 in different ways. While this situation distorts the aerial photo block, it corrects the shift effect of RPC in WorldView-2 and increases the accuracy. By using four or more GCPs, 1/2 pixel (similar to 0.23 m) accuracy in aerial photos and 1 pixel (similar to 0.50 m) accuracy in WorldView-2 can be achieved in horizontal. In vertical, aerial photos have 1 pixel (similar to 0.55 m) and WorldView-2 has 1.5 pixels (similar to 0.85 m) accuracy. These results show that Worldview-2 imagery can be used in the production of class I 1: 5000 scale maps according to the ASPRS Accuracy Standards for Digital Geospatial Data in terms of geometric accuracy. It is concluded that the rivalry between aerial and satellite imagery will continue for some time in the future.
Konvolusyonal Sinir Ağları Kullanılarak Normal, Romatoid Artrit ve Osteoartrit’li Direkt El Grafilerinin Ayrımı
(2019) Maraş, Hadi Hakan; 34410; 06.01. Bilgisayar Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Neuronavigation Skill Training Through Simulation: Insights From Eye Data
(Iated-int Assoc Technology Education A& development, 2016) Çağıltay, Nergiz; Tokdemir, Gül; Cagiltay, N. E.; Topalli, D.; Maraş, Hadi Hakan; Borcek, A. O.; Tokdemir, G.; Aydın, Elif; Maras, H. H.; Tonbul, G.; Aydin, E.; 17411; Yazılım Mühendisliği; Bilgisayar Mühendisliği; Elektrik-Elektronik Mühendisliği; 06.09. Yazılım Mühendisliği; 06.01. Bilgisayar Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Neuronavigation systems are developed to support the brain surgery operations. Because of its complex anatomical structure, the neurosurgery is a risky and critical operation. The surgeon is required to perform the operation in a very small area with very restricted movements. The neuronavigation systems are developed to help the surgeon during the operation to show the current position of the surgery with respect to the 3D virtual model of the patient. In these systems, the 3D virtual model of the patient is created according to the medical data (MRI/BT) of the patient. Hence these systems work like navigations systems that are used in driving a car. The surgeon uses this system by controlling the system through a software interface and its user interface and correlates the current position of the operation with the 3D patient virtual model. In this way the surgeon checks the critical anatomical structures through this system and eliminates possible risks. Hence surgeons who will perform such operations are required to develop several skills to manage this very complicated environment. They are required to perform the operation according to the information coming from the navigation display. Additionally, in order to reach relevant information from the navigation display they have to control the navigation panel. In order to prepare surgeons to manage this very complicated environment, their required skills need to be improved during the training period. In this study, to better understand the surgeons' behaviours while managing the tasks related to the surgical navigation procedures, a simulation based environment is developed and an experimental study is conducted with 10 people. Their eye data and their performance data is recorded based on the simulated tasks. The results of the study is analysed statistically and descriptively. The results show that it is possible to control a neuronavigation display through eye movements which could be an alternative human-computer interaction option for designing the neuronavigation systems' user interfaces. Secondly, it is shown that performing a task according to the results of a second information source (neuronavigation system) lowers the general performance in terms of travelled distance with the operation tool and camera (endoscope). However the success level while performing each task and the time spent values are similar in both cases. On the other hand the number of errors is higher in the first scenario. Hence, the surgical education programs need to provide appropriate solutions to better understand and measure the skill levels of trainees on such tasks and to improve their skills through virtual practice systems.
Problems of Gaining Neuronavigation Skills on Surgical Education Programs: A case study in Turkey
(2016) Cağıltay, Nergiz Ercil; Borcek, Alp Özgün; Tokdemir, Gül; Maraş, Hadi Hakan; Topallı, Damla; 17411; 34410; 06.01. Bilgisayar Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Neuronavigation technology is one of the important technologies that supports and guides the surgeons during the surgical procedures. Availability of this technology for the surgical education programs to gain the skills of using this technology effectively and efficiently during the surgical operations as well as availability of this technology in the operating room is critical for improving the surgical operations’ performance. In this study, the availability of this technology for the neurosurgical operations is researched through a quantitative research conducted by 220 neuro surgeons in Turkey. Based on the results of this study, suggestions for the education technology developers for creating technology enhanced education programs to increase the navigation skill levels of the candidate surgeons are developed. The results of this study aimed to improve the quality of the surgical education programs and the performance of the surgical procedures.
Türk beyin cerrahlarının teknolojiye ulaşım imkanları
(2016) Börcek, Alp Özgün; Çağıltay, Nergiz; Tokdemir, Gül; Maraş, Hadi Hakan; 17411; 34410; 06.09. Yazılım Mühendisliği; 06.01. Bilgisayar Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi