This item is non-discoverable
Tora, Hakan
Loading...
Name Variants
Tora,H.
T., Hakan
Tora, Hakan
H., Tora
H.,Tora
T.,Hakan
Hakan, Tora
T., Hakan
Tora, Hakan
H., Tora
H.,Tora
T.,Hakan
Hakan, Tora
Job Title
Doktor Öğretim Üyesi
Email Address
hakan.tora@atilim.edu.tr
Main Affiliation
Airframe and Powerplant Maintenance
Status
Former Staff
Website
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Scholarly Output
53
Articles
11
Citation Count
35
Supervised Theses
15
53 results
Scholarly Output Search Results
Now showing 1 - 10 of 53
Conference Object Citation - Scopus: 1Higher Order Statistical Analysis of Turkish Phones;(IEEE Computer Society, 2014) Tora,H.; Uslu,B.; Airframe and Powerplant MaintenanceIn this study, histograms of Turkish phones were examined using higher order cumulants. As is known, phones constituting a language, are composed of letters as vowels and consonants. These letters can also be grouped as voiced and unvoiced phones. It is observed that unvoiced letters show a Gaussian-like distribution and result in small values of skewness and kurtosis. On the other hand, vowels and voiced consonants lead to a non-Gaussian distribution. Voiced and unvoiced phones are related with their skewness and kurtosis values. It is empirically shown that higher order cumulants are likely to be a feature in describing Turkish phones. © 2014 IEEE.Article Yalıtık Sözcüklü Bir Türkçe Konuşma Tanıma Sisteminin Yapay Veri Artırımı ile Tasarımı ve Gerçekleştirimi(2020) Uslu, İbrahim Baran; Tora, Hakan; Sümer, Emre; Türker, Mustafa; Department of Electrical & Electronics Engineering; Airframe and Powerplant MaintenanceBu çalışmada toplamda doksan iki adet sesli komuttan oluşan bir yalıtık sözcüklü Türkçe konuşmatanıma sistemi tasarlanmış ve gerçekleştirilmiştir. Sistem, destek vektör makinesi (SVM) tabanlı olup,eğitimde kullanılan veri kümesi kaydedilen konuşmaların yapay olarak çeşitlendirilip artırılmasıyla eldeedilmiştir. Farklı yapay veri oranlarının tanıma başarımı üzerindeki etkisi incelenmiştir. Akustik öznitelikolarak, mel frekansı kepstral katsayıları (MFCC) kullanılmıştır. Ayrıca, ses aktivitesi tespitinin ve MFCCkatsayılarının tanıma başarımına etkileri de irdelenmiştir. Sonuçta doksan iki yalıtık komut için ortalama%92.6’lık doğrulukla çalışan bir konuşma tanıma sistemi geliştirilmiştirConference Object Citation - WoS: 0An Approach for Perceptual Similarity Detection Between Audios Independent of Genre Via Metadata Extraction and Correlation(Ieee, 2007) Komsu, Fatma; Tora, Hakan; Oeztoprak, Kasim; Tora, Hakan; Tora, Hakan; Airframe and Powerplant Maintenance; Airframe and Powerplant MaintenanceThis study presents an approach for perceptual similarity detection between audios independent of genre. The study is formed of three phases; signal pre-processing as the first phase, metadata extraction via various perceptually compatible features as the second phase, and correlation methodology for similarity identification as the third phase. The performance and relative importance of the selected features for perceptual similarity analysis are presented, as testing results. Moreover, relative importance of preprocessing is introduced. Using the proposed methodology, perceptual similarity detection between genre independent audios is achieved with a 96.85% performance. Contribution highly lies on the independency of genre.Conference Object Citation - Scopus: 3Emotion classification using hidden layer outputs(2012) Günler,M.A.; Tora,H.; Airframe and Powerplant MaintenanceNeural network (NN) with Multi-Layer Perceptron (MLP) is a supervised learning algorithm composed of artificial neurons. Multilayer NN is capable of solving nonlinear classification problems such as emotion identification by using facial expressions that is presented in this paper. Hidden layer outputs of NN provide useful information about facial appearance. This study addresses that without fully training NN hidden layer outputs can be used as feature. It is shown that an acceptable recognition rate is obtained by means of hidden layer outputs. © 2012 IEEE.Conference Object Citation - Scopus: 1Effect of Secret Image Transformation on the Steganography Process(Institute of Electrical and Electronics Engineers Inc., 2017) Buke,M.; Tora,H.; Gokcay,E.; Airframe and Powerplant Maintenance; Software EngineeringSteganography is the art of hiding information in something else. It is favorable over encryption because encryption only hides the meaning of the information; whereas steganography hides the existence of the information. The existence of a hidden image decreases Peak Signal to Noise Ratio (PSNR) and increases Mean Square Error (MSE) values of the stego image. We propose an approach to improve PSNR and MSE values in stego images. In this method a transformation is applied to the secret image, concealed within another image, before embedding into the cover image. The effect of the transformation is tested with Least Significant Bit (LSB) insertion and Discrete Cosine Transformation (DCT) techniques. MSE and PSNR are calculated for both techniques with and without transformation. Results show a better MSE and PSNR values when a transformation is applied for LSB technique but no significant difference was shown in DCT technique. © 2017 IEEE.Conference Object Citation - Scopus: 2Real Time Infrared Image Enhancement;(2012) Akdeniz,N.; Tora,H.; Airframe and Powerplant MaintenanceThis study evaluates the implementation of Balanced Contrast Limited Adaptive Histogram Equalization (BCLAHE) for infrared images (IR) on an embedded platform. The aim was to achieve real time performance for the operator display target application. The system configured for this aim is a dual processor media application device OMAP3530, which consists of an ARM and a DSP processor. System is configured so that hardware sources are used efficiently and various performance improvement techniques are investigated. Performance analysis is done over IR images with different dynamic range. © 2012 IEEE.Conference Object Citation - WoS: 0Design and Implementation of an Expressive Talking Mobile Robot: Toztorus(Ieee, 2018) Tozan, Ozalp; Tora, Hakan; Uslu, Baran; Unal, Bulcnt; Ceylan, Ece; Computer Engineering; Airframe and Powerplant MaintenanceThis paper is about a brand new robot and all its development stages from the design to the show time. As an undergraduate research project (the LAP program at Atilim University), the robot TozTorUs is the outcome of the dense efforts of a team. With the sensors equipped, it navigates autonomously in the environment in which it is located by avoiding the obstacles. It can understand your questions and answer them using Google's speech technologies. Although it is not a humanoid robot, with eyes and mouth simulator LED displays, it is as friendly as a human. We can also control TozTorUs using a mobile phone. Apart from these, it is able to adjust its height with respect to the visitor's, thus allowing it to make an eye contact with the person. Although TozTorUs is designed for welcoming, it may also be employed for consulting, security and elderly assistance.Article Citation - WoS: 3Citation - Scopus: 3An Unrestricted Arnold's Cat Map Transformation(Springer, 2024) Turan, Mehmet; Goekcay, Erhan; Tora, Hakan; Software Engineering; Mathematics; Airframe and Powerplant MaintenanceThe Arnold's Cat Map (ACM) is one of the chaotic transformations, which is utilized by numerous scrambling and encryption algorithms in Information Security. Traditionally, the ACM is used in image scrambling whereby repeated application of the ACM matrix, any image can be scrambled. The transformation obtained by the ACM matrix is periodic; therefore, the original image can be reconstructed using the scrambled image whenever the elements of the matrix, hence the key, is known. The transformation matrices in all the chaotic maps employing ACM has limitations on the choice of the free parameters which generally require the area-preserving property of the matrix used in transformation, that is, the determinant of the transformation matrix to be +/- 1.\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm 1.$$\end{document} This reduces the number of possible set of keys which leads to discovering the ACM matrix in encryption algorithms using the brute-force method. Additionally, the period obtained is small which also causes the faster discovery of the original image by repeated application of the matrix. These two parameters are important in a brute-force attack to find out the original image from a scrambled one. The objective of the present study is to increase the key space of the ACM matrix, hence increase the security of the scrambling process and make a brute-force attack more difficult. It is proved mathematically that area-preserving property of the traditional matrix is not required for the matrix to be used in scrambling process. Removing the restriction enlarges the maximum possible key space and, in many cases, increases the period as well. Additionally, it is supplied experimentally that, in scrambling images, the new ACM matrix is equivalent or better compared to the traditional one with longer periods. Consequently, the encryption techniques with ACM become more robust compared to the traditional ones. The new ACM matrix is compatible with all algorithms that utilized the original matrix. In this novel contribution, we proved that the traditional enforcement of the determinant of the ACM matrix to be one is redundant and can be removed.Conference Object Citation - WoS: 1THE USE OF CUMULANTS FOR VOICED-UNVOICED SEGMENTS IDENTIFICATION IN SPEECH SIGNALS(Ieee, 2014) Uslu, Baran; Tora, Hakan; Airframe and Powerplant MaintenanceIn this study, voiced-unvoiced classification performance of Turkish sounds using skewness and kurtosis is examined. The analyses show that higher order cumulants can be employed as a feature in voiced-unvoiced classification that is vital in speech processing applications. Furthermore, it has been shown that cumulants are also useful for identifying voiced and unvoiced segments in noisy speech signals.Master Thesis Rc8660 Ses Sentezleyici ile Türkçe Metinden Konuşma Sentezleme(2015) Karamehmet, Timur; Tora, Hakan; Uslu, İbrahim Baran; Airframe and Powerplant MaintenanceBu çalışma, metinden konuşma sentezleme problemini ve RC8660 gömülü sisteminin Türkçe'ye uyarlanması için yapılan çalışmaları incelemektedir. Tezde, İngilizce fonemlerle yüklü gelen RC8660 kartının Türkçe konuşma sentezlemesi hedeflenmiştir. Bu amaçla, öncelikle İngilizce'de bulunan fonemlere karşılık gelen Türkçe fonemler tanımlanmıştır. Bunun için IPA: International Phonetic Alphabet'den yararlanılmıştır. Türkçe ve İngilizce'nin hece yapıları farklı olduğu için, kartın sahip olduğu metin ve fonem modlarından yararlanılarak yeni bir harici sözlük tanımlamaya ihtiyaç duyulmuştur. Doğru heceleme için gerekli kurallar, oluşturulan bu sözlüğe tek tek eklenmiştir. RC8660'ın bir konuşmacı doğallığında Türkçe konuşması için vurgu ve tonlama kuralları da tanımlanmıştır. Üretilen konuşmanın düzgün ve anlaşılabilir olması amacıyla karakterler ve sayılar için farklı fonemler kullanılmıştır. Kartın yazılımı olan RC Studio'da yer alan hız, ifade, perde, formant frekansı, ton, gecikme ve telaffuz ayarlarının konuşma üzerindeki etkileri de test edilmiştir. Üretilen konuşmanın kalitesi ortalama görüş skoru (MOS) testi ile ölçülmüştür.
