Bilgisayar Mühendisliği Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1940

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Citation - WoS: 7
Citation - Scopus: 3
Facial Landmark Localization in Depth Images Using Supervised Ridge Descent
(2015) Camgoz, Necati Cihan; Gökberk, Berk; Akarun, Lale; Struc, Vitomir; Kindiroglu, Ahmet Alp
Supervised Descent Method (SDM) has proven successful in many computer vision applications such as face alignment, tracking and camera calibration. Recent studies which used SDM, achieved state of the-art performance on facial landmark localization in depth images [4]. In this study, we propose to use ridge regression instead of least squares regression for learning the SDM, and to change feature sizes in each iteration, effectively turning the landmark search into a coarse to fine process. We apply the proposed method to facial landmark localization on the Bosphorus 3D Face Database; using frontal depth images with no occlusion. Experimental results confirm that both ridge regression and using adaptive feature sizes improve the localization accuracy considerably.
Citation - WoS: 4
Citation - Scopus: 8
Facial Landmark Localization in Depth Images Using Supervised Descent Method
(2015) Gökberk, Berk; Akarun, Lale; Camgoz, Necati Cihan
This paper proposes using the state of the art 2D facial landmark localization method, Supervised Descent Method (SDM), for facial landmark localization in 3D depth images. The proposed method was evaluated on frontal faces with no occlusion from the Bosphorus 3D Face Database. In the experiments, in which 2D features were used to train SDM, the proposed approach achieved state-of-the-art performance for several landmarks over the currently available 3D facial landmark localization methods.
Citation - WoS: 4
Citation - Scopus: 5
Private Minutia-Based Fingerprint Matching
(2015) Sarıer, Neyire Deniz
In this paper, we propose an efficient biometric authentication protocol for fingerprints particularly suited for the minutia-based representation. The novelty of the protocol is that we integrate the most efficient (linear complexity) private set intersection cardinality protocol of Cristofaro et al. and a suitable helper data system for biometrics in order to improve the accuracy of the system. We analyze the security of our scheme in the standard model based on well-exploited assumptions, considering malicious parties, which is essential to eliminate specific attacks on biometric authentication schemes designed for semi-honest adversaries only. Finally, the complexity is compared to the existing provably secure schemes for fingerprint matching, which shows that the new proposal outperforms them both in semi-honest and malicious security models.
Citation - WoS: 1
Citation - Scopus: 1
Security Analysis of Revocable and Bipartite Biotokens
(2015) Sarıer, Neyire Deniz
In this paper, we analyze the security of bipartite biotokens that release a secret key hidden in the biotoken by using biometrics. We show that the biotoken encoding of 80/112/128-bit symmetric encryption keys are vulnerable to brute force attacks, whose complexity is lower than cryptographic security. Also, we present the weaknesses in the design of revocable biotokens that form the basis for bipartite biotokens. Finally, we propose countermeasures to prevent these attacks and discuss the employment of other efficient cryptographic techniques that possess provable security guarantees.
Corner Detection by Local Zernike Moments
(2015) Ozbulak, Gokhan; Gökmen, Muhittin
In this paper, our corner-based interest point detector, Robust Local Zernike Moment based Features (R-LZMF), which was proved to be scale, rotation and translation-invariant, is investigated for invariance against affine transformation, lighting and blurring. Furthermore, R-LZMF's corner detection capability with Zernike moments of order 4 is theoretically explained in detail. Experimental results on the Inria Dataset show that R-LZMF outperforms SIFT, CenSurE, ORB, BRISK and competes with SURF in terms of repeatability for images under affine transformation and photometric deformation such as lighting and blurring.
Yüz Tanıma
(Elektrik Mühendisleri Odası EMO), 2015) Muhittin, Gökmen
Görüntü işleme alanında çalışan 36 farklı üniversiteden 52 doktora ve yüksek lisans öğrencisinin katılımı ile başlayan akademik kampta, alanında uzmanlıkları ile tanınan 11 farklı üniversiteden 14 akademisyenin katılımıyla 17 farklı seminer ve ders gerçekleştirildi. 2. Akademik Kamp çalışmalarına, 16 Nisan 2015 tarihinde saat 09:00`da açılış töreni ile başladı. Açılışta ilk olarak konuşan EMO Müdürü Emre Metin, kamp çalışmalarına ilişkin temel bilgileri katılımcılara aktardı. Metin`in ardından kürsüye gelen EMO Yönetim Kurulu Başkanı Hüseyin Yeşil ise konuşmasına kamp çalışmalarına katkı veren EMO MİSEM Komisyonu Başkanı Orhan Örücü, Prof . Dr. Tayfun Akgül ve kampa ev sahipliği yapan Nesin Vakfı`na teşekkür ederek, başladı. EMO Akademiyle Bağını Güçlendiriyor EMO`nun akademi dünyası ile daha yakın ilişki kurmayı hedeflediğine dikkat çeken Yeşil, ikincisi yapılan akademik kampı tekrarlamak istediklerini kaydetti. EMO`nun kendi meslek alanlarına giren üniversitelerin ilgili bölümleri ile özel ilişkiler kurmaya çalıştığını ifade eden Yeşil, bu kapsamda 25 Ekim 2014 tarihinde 56 bölüm başkanı ile bir toplantı düzenlediklerini kaydetti. EMO ve üniversite çalışmalarının koordine edilebilmesi için 11 Nisan 2015 tarihinde bir toplantı daha gerçekleştirildiğini ifade eden Yeşil, bu kapsamda Elektrik-Elektronik-Kontrol-Biyomedikal Mühendisliği Bölüm Başkanları Konseyi`nin de kurulduğunu bildirdi. EMO tarafından yayımlanan EMO Bilimsel Dergi ile alandaki bilimsel dergi ihtiyacının giderilmeye çalışıldığını ifade eden Yeşil, derginin 8. sayının hazırlıklarının yapıldığını kaydetti. Genç akademisyenlerden EMO Bilimsel Dergisi için makale katkısı isteyen Yeşil, baş editör Prof. Dr. Hamit Serbest ve diğer dergi editörlerine katkıları dolayısıyla teşekkür etti. EMO`nun Meslek İçi Eğitim Merkezi (MİSEM) çalışmaları kapsamında yürüttüğü eğitim ve seminerlere de dikkat çeken Yeşil, mesleki ve teknik gelişmelerin bu eğitimlerle üyelere aktarılmaya çalışıldığını vurguladı. EMO`nun mesleki ve teknik gündemin yanında toplumsal yaşamda da katkılar sağlamaya çalıştığını ifade eden Yeşil, konuşmasını şöyle sürdürdü: "Yalnızca Soma`da yaşanan iş cinayeti hem de tüm Türkiye`yi karanlıkta bırakan elektrik kesintisi konularında bile kamuoyunu bilgilendirme çabalarımız bile EMO`nun varlığının önemli olduğunu ortaya koymaktadır. Gerçeklerin ortaya çıkması için yürütmeye çalıştığımız bu çalışmaların genç arkadaşlarımızın da katkılarıyla güçlenerek, süreceğine inanıyoruz." Yeni Kamplar Geliyor Yeşil`in ardından kürsüye gelen EMO MİSEM Komisyonu Başkanı Orhan Örücü ise konuşmasına daha önce düzenlenen akademik kampa ilişkin bilgi aktararak başladı. Örücü, Akademik Kampa 36 farklı üniversiteden toplam 52 öğrencinin katılım sağlamasının önemine işaret ederek, kampta yer alan genç 20 kadın akademisyeni de kutladı. Akademik kampların farklı konularda daha sık periyotlarda tekrarlanması için çalışmalar yürütüldüğünü ifade eden Örücü, ODTÜ`den Prof. Dr. Murat Eyüpoğlu ile birlikte "Manyetik Görüntüleme", yine ODTÜ`den Prof. Dr. Bülent Ertan ile "Elektrik Makineleri ve Güç Elektroniği" ve İTÜ`den Doç. Dr. Neslihan Şengür ile "Yapay Sinir Ağları" konularına ilişkin kamp düzenlenebilmesi için çalışmalar yürütüldüğünü bildirdi. Örücü, hazırlık çalışmaları kapsamında seminerlere katılacak deneyimli akademisyenlerin belirlenmesi için önümüzdeki dönemde genç akademisyenler arasından EMO tarafından anketler düzenleneceği ve öneriler alınacağını kaydetti. Örücü`nün ardından konuşan Prof. Dr. Tayfun Akgül ise bir önceki kamp çalışmalarına değinerek, "çok keyifli" bir çalışma sürecinin yaşandığını kaydetti. Akgül, akademik kampların daha sıcak ilişkiler yaratarak, çalışmaların ivmesini artırdığına dikkat çekti. Nesin Vakfı`na Matematik Köyü`nden yarattığı çalışma ortamı için teşekkür eden Akgül, tüm katılımcıların kamp çalışmalarında önemli katkılar sağlayacağına inandığını ifade etti. Akgül`ün konuşmasını tamamlamasının ardından, katılımcılar kendini tanıtarak yaptıkları çalışmalara ilişkin bilgi aktardı. Kampta daha sonra Prof. Dr. Muhittin Gökmen`in verdiği "Yüz Tanıma" başlıklı derse geçildi. Kampta ilk gün çalışmaları kapsamında Gökmen`in yanı sıra Prof. Dr. Tayfun Akgül "Bilim Etiği", Prof. Dr. Hamit Serbest "Bilim, Mühendislik ve Öğretim Kurumları", Prof. Dr. Tayfun Akgül "Yüzsüz Yüz Tanıma" ve Prof. Dr. Enis Çetin "Orman Yangını Bulma, Örüntü Tanıma, Mikroskop Görüntülerinin İşlenmesi" konu başlıklarında seminerler verdi. Kamp çalışmaları kapsamında 17 Mart 2015 Cuma günü ise ilk olarak EMO Bilimsel Dergi Yayın Kurulu Üyesi Prof. Dr. Altay Güvenir tarafından "EMO Bilimsel Dergi Tanıtımı" başlıklı oturum düzenlendi. Ardından Prof. Dr. Atilla Bir`in tarafından ise katılımcılara "Öklid`ten Nasreddin Tusi`ye, Tusi`den Uluğ Bey‘e Bilim" başlıklı sunum gerçekleştirildi. Kamp çalışmaları kapsamında öğlden sonra Prof. Dr. Ayşin Ertüzün tarafından "Doku Analizi ve Örüntü Tanıma", Yrd. Doç. Dr. Emre Sümer tarafından ise "Görüntü İşleme Teknikleri ile 3-B Bina Modelleme" dersleri verildi. Günün son dersinin ise Prof. Dr. Ali Nesin, "Mühendisler ve Matematik; Sayı Ne Demektir?" başlıklığı altında yaptı. Cumartesi günü ise ilk olarak Yrd. Doç. Dr. Berk Gökberk`ün "Biyometri", Prof. Dr. Arif Nacaroğlu`nun "Sıkıştırılmış Sinyallerin Algılanması", Yrd. Doç. Dr. Özlem Durmaz İncel`in "İnsan Eylemi ve Bağlam Tanıma" ve Prof. Dr. A. Aydın Alatan`ın "Ardışık Görüntülerden Sahne Derinliği Kestirimi" başlıklı dersleri gerçekleştirildi. Kampın son gününde ise Yrd. Doç. Dr. Alper Selver`in "Sıradüzenli Sistemlerin Günlük Yaşam Uygulamaları: Kalite Tespiti, Organ Görüntüleme ve Radarla Nesne Tespiti" ile Doç. Dr. Hazım Kemal Ekenel`in "İçerik Tabanlı İmge ve Video Çıkarımı" başlıklı dersleri yapıldı. Kamp çalışmaları Efes Harabeleri`ne ve Şirince Köyü`ne yapılan gezi ile tamamlandı.
Data Deduplication With Adaptive Erasure Code Redundancy (us20160013815a1)
(2016) Arslan, Şuayb Şefik; Wideman, Roderick; Lee, Jaewook; Göker, Turguy
Example apparatus and methods combine erasure coding with data deduplication to simultaneously reduce the overall redundancy in data while increasing the redundancy of unique data. In one embodiment, an efficient representation of a data set is produced by deduplication. The efficient rep resentation reduces duplicate data in the data set. Redundancy is then added back into the data set using erasure coding. The redundancy that is added back in adds protection to the unique data associated with the efficient representation. How much redundancy is added back in and what type of redundancy is added back in may be controlled based on an attribute (e.g., value, reference count, symbol size, number of symbols) of the unique data. Decisions concerning how much and what type of redundancy to add back in may be adapted over time based, for example, on observations of the efficiency of the overall system.
Efficient High/Low Energy Zone Solid State Device Data Storage
(2016) Arslan, Şuayb Şefik; Göker, Turguy
Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include circuits that produce EC encoded data that has a likelihood of use, that select a location to store the EC encoded data in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC encoded data in the loca tion, and that compute an order of retrieval for EC encoded data stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC encoded data may also have a priority based on the number of erasures for which the EC corrects.
Power Savings in Cold Storage
(2016) Arslan, Şuayb Şefik; Göker, Turguy
Methods and apparatus associated with data cold storage are described. Example apparatus include an array of data storage devices arranged in rows and columns. Columns of the array are orthogonal to rows. A row has an associated row-centric power supply, and a column has an associated column-centric local electronics module (LEM) that controls a data storage device in the column independently of other data storage devices in the array. Example apparatus include logics that control a power mode of a data storage device independently of other data storage devices in the array, that control a power mode of an LEM, that adaptively regulate the level of data stored in a buffer, and that determine whether a data object will be stored in the buffer or stored on a data storage device in the array, based on the probability the data object will be accessed within a threshold period of time.
Citation - WoS: 2
Citation - Scopus: 2
Implementation of Multi-Threaded Erasure Coding Under Multi-Processing Environments
(2016) Arslan, Şuayb Şefik
Galois alan aritmetiği depolama ve iletişim cihazlarını veri kayıplarına karşı korumak için Reed-Solomon silme kodlarının temelini oluşturmaktadır. Galois alan aritmeti^ginin en güncel uygulamaları hızlı Galois alan hesaplamaları yapmamıza imkan sağlayan Intel’in SIMD eklerinde olduğu gibi 128-bitlik işlemci vektör talimatlarına dayanmaktadır. Buna rağmen, bu uygulamalar çoklu–dizin ve çoklu–süreçli ortamlara göre optimize edilmemiştir. Diğer taraftan, sunucuların çoklu istekleri eş zamanlı olarak yerine getirmesi ve donanımın sağladığı tüm paralelliği kodlama yükünü etkili yürütmek için kullanması arzu edilmektedir. Bu makale silme kodlarının çoklu-dizin işlemcilerle çoklu–süreçli ortamlarda nasıl kullanılaca^gının detaylarını sunmakta ve tek dizinli uygulamalara göre emtia mikro işlemciler ve Jerasure 2.0 yazılım kütüphanesini kullanarak önemli ölçüde performans artışının olabileceğini göstermektedir.
Citation - WoS: 1
Citation - Scopus: 1
Face Recognition With Local Zernike Moments Features Around Landmarks
(IEEE, 2016) Gökmen, Muhittin
In this paper, a new method that extracts the features from the complex Local Zernike Moments (LZM) images around facial landmarks is proposed. In this method, multiple grids which are in different sizes are located on landmarks and Phase-Magnitude (PM) histograms are calculated in each cells of these grids. The PM histograms are calculated for every component of LZM and the feature vectors are created by concatenating these histograms. By reducing the dimensionality of these vectors using Whitened Principle Component Analysis, more robust descriptors are constructed. It is shown that the state-of-the-art results are obtained in the experiments performed on FERET database using the proposed method. © 2016 IEEE.
Detecting the Effect of Voice-Over in Tv Ads Via Optic Brain Imaging (fnirs) and In-Depth Interview Methods
(2016) Çakar, Tuna; Girisken, Yener
Voice-overs are used extensively to increase the effectiveness of the TV ads especially in the last decade. The main purpose is to provide the brand message via a clear feature that will inevitably grab the attention of the viewers. The current study contains the neuro tests of 12 TV ads in banking and finance sectors on 168 participants in 8 groups. Optic brain imaging (fNIRS) and in-depth interviews were the methodologies utilized during the test of these TV ads. The obtained results indicate that the use of voice-over during the TV ads possibly causes the decrease in attention and emotional engagement levels of the participants.
High/Low Energy Zone Data Storage
(2016) Göker, Turguy; Arslan, Şuayb Şefik
Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include logics that produce an EC that has a likelihood of use, that select a location to store the EC in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC in the location, and that compute an order of retrieval for an EC stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC may also have a priority based on the number of erasures for which the EC corrects.
Citation - Scopus: 3
Openmp and Posix Threads Implementation of Jerasure 2.0
(2017) Arslan, Şuayb Şefik; Le, Hoa; Landman, Joseph; Goker, Turguy
In shared memory multiprocessor architectures, threads can be used to implement parallelism. POSIX threads (pthreads) is a low-level bare-bones programming interface for working with threads. Therefore, we have extremely fine-grained control over thread management (create/join/etc), mutexes, and so on. On the other hand, openMP, as a shared-memory standard, is much higher level and portable interface which makes it easier to use multi-threading capability and obtain satisfactory performance improvements. Since pthreads is more flexible, it helps programmers gain more control on performance optimizations. Jerasure 2.0 erasure coding library has encoding/decoding engines which comprise independent "for" loop iterations and hence possess huge potential for multi-threaded processing. In this short paper, we investigate multi-threaded implementations of encoder/decoder pair of Jerasure 2.0 using two different technologies: OpenMP and pthreads. We constrain our changes to a minimum possible and compare the pure encoding/decoding performance with respect to each other as well as against that of the original single-threaded version by running them on two different server systems.
Citation - Scopus: 7
The Use of Neurometric and Biometric Research Methods in Understanding the User Experience During Product Search of First-Time Buyers in E-Commerce - Conference Paper
(Springer, 2017) Rızvanoğlu, Kerem; Gürvardar, İrfan; Çakar, Tuna; Öztürk, Özgürol; Zengin Çelik, Deniz
Understanding user experience (UX) during e-commerce has been a relatively important research area especially in the last decade. The use of conventional methods in UX such as task-observation, in-depth interviews and questionnaires has already contributed for the measurement of the efficiency and effectiveness. This empirical study has aimed to make use of both conventional and neuroscientific methods simultaneously to provide a richer analysis framework for understanding the product search experience of the first-time buyers. The current work provides insights for the results from the combined use of conventional and neuroscientific-biometric methods in a UX study. Although this has been an exploratory study within a limited literature, the obtained results indicate a potential use of these methods for UX research, which may contribute to improve the relevant experience in various digital platforms.
Citation - WoS: 2
Citation - Scopus: 2
Facial Expression Recognition From Still Images
(2017) Gökmen, Muhittin; Gazioglu, Bilge Suheyla Akkoca
With the development of technology, Facial Expression Recognition (FER) become one of the important research areas in Human Computer Interaction. Changes in the movement of some muscles in face create the facial expressions. By defining these changes, facial expressions can be recognized. In this study, a cascaded structure consists of Local Zernike Moments (LZM), Local XOR Patterns (LXP) and Global Zernike Moments (GZM) methods is proposed for the FER problem. The generally used database is the Extended Chon - Kanade (CK +) in FER problems. The database consists of image sequences of 327 expressions of 118 people. Most FER system includes recognition of 7 classes of emotions happiness, sadness, surprise, anger, disgust, fear and contempt, and we use Library of Support Vector Machines (LIBSVM) classifier for multi class classification with the leave one out cross-validation method. Our overall system performance is measured as 90.34% for FER.
Citation - WoS: 3
Citation - Scopus: 2
A Joint Dedupe-Fountain Coded Archival Storage
(2017) Arslan, Şuayb Şefik; Göker, Turguy; Wideman, Rod
An erasure-coded archival file storage system is presented using a chunk-based deduplication mechanism and fountain codes for space/time efficient operation. Unlike traditional archival storage, this proposal considers the deduplication operation together with correction coding in order to provide a reliable storage solution. The building blocks of deduplication and fountain coding processes are judiciously interleaved to present two novel ideas, reducing memory footprint with weaker hashing and dealing with the increased collisions using correction coding, and applying unequal error protection to deduplicated chunks for increased availability. The combination of these two novel ideas made the performance of the proposed system stand out. For example, it is shown to outperform one of the replication-based as well as RAID data protection schemes. The proposed system also addresses some of the fundamental challenges of today's low-cost deduplicated data storage systems such as hash collisions, disk bottleneck and RAM overflow problems, securing savings up to 90% regular RAM use.
Citation - WoS: 2
Citation - Scopus: 5
Mojette Transform Based Ldpc Erasure Correction Codes for Distributed Storage Systems
(2017) Arslan, Şuayb Şefik; Normand, Nicolas; Parrein, Benoit
Mojette Transform (MT) based erasure correction coding possesses extremely efficient encoding/decoding algorithms and demonstrate promising burst erasure recovery performance. MT codes are based on discrete geometry and provide redundancy through creating projections. Projections are made of smaller data structures called bins and are generated from a two dimensional convex-shaped data. For exact data recovery, only a subset of projections are needed by the decoder. We realize that the discrete geometry definition of MT erasure codes corresponds to creating structured/deterministic generator matrices. In this study, we show an alternative Low Density Parity Check (LDPC) code construction methodology through investigating parity check matrices of MT codes which shows sparseness as the blocklength of the code gets large. In a distributed storage setting, we also quantify the repair bandwidth and show that this novel interpretation can be used to facilitate bin-level local repairs.
Removable Media Based Object Store
(2017) Wideman, Roderick; Arslan, Şuayb Şefik; Göker, Turguy
Embodiments disclosed herein provide systems, methods, and computer-readable media to implement an object store with removable storage media. In a particular embodiment, a method provides identifying first data for storage on a first removable storage medium and designating at least a portion of the first data to a first data object. The method further provides determining a first location where to store the first data object in a first value store partition of the first remov able storage medium and writing the first data object to the first location. Also, the method provides writing a first key that identifies the first data object and indicates the first location to a first key store partition of the first removable storage medium.
Adaptive Erasure Codes
(2017) Arslan, Şuayb Şefik; Göker, Turguy
Methods, apparatus, and other embodiments associated with adaptive use of erasure codes for distributed data storage systems are described. One example method includes accessing a message, where the message has a message size, selecting an encoding strategy as a function of the message size, data storage device failure statistics, data storage device wear periods, data storage space constraints, or overhead constraints, and where the encoding strategy includes an erasure code approach, generating an encoded message using the encoding strategy, generating an encoded block, where the encoded block includes the encoded mes sage and metadata associated with the message, and storing the encoded block in the data storage system. Example methods and apparatus may employ Reed Solomon erasure codes or Fountain erasure codes. Example methods and apparatus may display to a user the storage capacity and durability of the data storage system.

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