Browsing by Author "Tolun, Mehmet R."

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Citation Count: Choupani, Roya; Wong, Stephan; Tolun, Mehmet R., "A drift-reduced scheme for hierarchical wavelet coding scalable video transmissions", 2009 First International Conference On Advances In Multimedia, (2009).
A drift-reduced scheme for hierarchical wavelet coding scalable video transmissions
(IEEE, 2009) Choupani, Roya; Wong, Stephan; Tolun, Mehmet R.
Scalable video coding allows for the capability of (partially) decoding a video bitstream when faced with communication deficiencies such as low handwidth or loss of data resulting in lower video quality. As the encoding is usually based on perfectly reconstructed frames, such deficiencies result in differently decoded frames at the decoder than the ones used in the encoder and, therefore, leading to errors being accumulated in the decoder. This is commonly referred to as the drift error. Drift-free scalable video coding methods also suffer from the low performance problem as they do not combine the residue encoding scheme of the current standards such as MPEG-4 and H.264 with scalability characteristics. We propose a scalable video coding method which is based on the motion compensation and residue encoding methods found in current video standards combined with the scalability property of discrete wavelet transform. Our proposed method aims to reduce the drift error while preserving the compression efficiency. Our results show that the drift error has been greatly reduced when a hierarchical structure for frame encoding is introduced.
Citation Count: Choupani, Roya; Wong, Stephan; Tolun, Mehmet R. "Adaptive Embedded Zero Tree for Scalable Video Coding", World Congress On Engıneering, Wce 2011, Vol Iı, pp. 1567-1571, (2011).
Adaptive Embedded Zero Tree For Scalable Video Coding
(Int Assoc Engineers-Laeng, 2011) Choupani, Roya; Wong, Stephan; Tolun, Mehmet R.; 1863
Video streaming over the Internet has gained popularity during recent years mainly due to the revival of video-conferencing and video-telephony applications and the proliferation of (video) content providers. However, the heterogeneous, dynamic, and best-effort nature of the Internet cannot always guarantee a certain bandwidth for an application utilizing the Internet. Scalability has been introduced to deal with such issues (up to a certain point) by adapting the video quality with the available bandwidth. In addition, wavelet based scalability combined with representation methods such as embedded zero trees (EZWs) provides the possibility of reconstructing the video even when only the initial part of the streams have been received. EZW prioritizes the wavelet coefficients based on their energy content. Our experiments however, indicate that giving more priority to low frequency content improves the video quality at a specific bit rate. In this paper, we propose a method to improve on the compression rate of the EZW by prioritizing the coefficients by combining each frequency sub-band with its energy content. Initial experimental show that the first two layers of the generated EZW are about 22.6% more concise.
Citation Count: Medeni, İ.T.; Aktaş, Z.A.; Tolun, M.R. "Bilgi Biliminin Mühendislik Gereksinimi ve Bilgi Mühendisliği", Elektrik Elektronik Bilgisayar Biomedikal Mühendisleri Eğitimi 4. Ulusal Sempozyumu, 2009.
Bilgi Biliminin Mühendislik Gereksinimi ve Bilgi Mühendisliği
(2009) Medeni, İhsan Tolga; Aktaş, A. Ziya; Tolun, Mehmet R.; 1863
Yirminci yüzyılın ikinci yarısında bilgisayar, bilgi ve iletişim teknolojilerindeki gelişmeler bilgiye dayalı yeni bilim ve mühendislik disiplinleri oluşturma ihtiyacını doğurmuştur. Bu ihtiyaç nedeniyle doğan yeni bilim ve mühendislik disiplinlerinin gelişiminin aslında (veri, enformasyon ve bilgi ) üçlüsüne yönelik oluşumlar olduğu gözlemlenmektedir.Bu makalede bilgi sözcüğü bu üçlü için genel bir ad olarak kullanılacaktır. Bilgi disiplini bir taraftan, bu üçlü arasındaki bağların örgütler ve bireyler açısından ortaya koyulmasını amaçlar; açık ve örtük bilginin birbirine dönüşümünü sağlamaya çalışırken, diğer taraftan da ortaya çıkan yeni dallar ve var olan dalların bilgi temelli ilişkisini kurmaya yönelik çalışmalar yapmaktadır. Bu üçlünün ve bilgi disiplininin bilim / mühendislik, işletme / yönetim disiplinleriyle olan ilişkisi ve oluşturulacak bir bilgi mühendisliği lisans programının bu kavramlarla olabilecek ilgisi bu bildirinin konusudur.
Citation Count: Yildirim, Pinar...et al. "Clustering Analysis for Vasculitic Diseases", Networked Digital Technologies, Pt 2, Vol. 88, pp. 36-+, (2010).
Clustering Analysis for Vasculitic Diseases
(Springer-Verlag Berlin, 2010) Yıldırım, Pınar; Çeken, Çınar; Çeken, Kağan; Tolun, Mehmet R.; 1863
We introduce knowledge discovery for vasculitic diseases in this paper. Vasculitic diseases affect some organs and tissues and diagnosing can be quite difficult. Biomedical literature can contain hidden and useful knowledge for biomedical research and we develop a study based on co-occurrence analysis by using the articles in MEDLINE which is a widely used database. The mostly seen vasculitic diseases are selected to explore hidden patterns. We select PolySearch system as a web based biomedical text mining tool to find organs and tissues in the articles and create two separate datasets with their frequencies for each disease. After forming these datasets, we apply hierarchical clustering analysis to find similarities between the diseases. Clustering analysis reveals some similarities between diseases. We think that the results of clustered diseases positively affect on the medical research of vasculitic diseases especially during the diagnosis and certain similarities can provide different views to medical specialists.
Citation Count: Altunel, Yusuf; Tolun, Mehmet R.; Sobh, T. (2008). "Component-Based Project Estimation Issues for Recursive Development", Advances in Computer and Informatiom Sciences and Engineering, pp. 577-+.
Component-Based Project Estimation Issues for Recursive Development
(2008) Altunel, Yusuf; Tolun, Mehmet R.; Sobh, T.; 1863
In this paper we investigated the component-based specific issues that might affect project cost estimation. Component-based software development changes the style of software production. With component-based approach the software is developed as the composition of reusable software components. Each component production process must be treated as a stand-alone software project, which needs individual task of management. A typical pure component-based development can be considered as decomposition/integration activities successively applied at different levels and therefore results in recursive style of development. We analyzed and presented our results of studies on the component-based software development estimation issues from recursive point of view.
Citation Count: Altunel, Yusuf; Tolun, Mehmet R., "Component-based software development with component variants", Proceedings Of The Iasted International Conference On Software Engineering, (2007).
Component-based software development with component variants
(Acta Press Anaheim, 2007) Altunel, Yusuf; Tolun, Mehmet R.
Variants are the new units suggested for component-based software implementation to contain just one set of features that a traditional component might normally contain. They help us to implement the specialization of components without the need for long inheritance trees and strong dependencies in object oriented counterpart. Variants can become very effective in component customization process when the variant production is automated by means of variant generators. In this paper we provide a simple component-based methodology based on the variants that help us to implement software in pure component-based manner. Such an approach guarantees the execution of a uniform processes throughout the whole software development operation. A system produced by our methodology has the capacity to produce many generic and domain specific components as by-products that can be utilized in further applications. Our methodology includes the activities to identify, represent, decompose and optimize the components, sub-components and their variants.
Citation Count: Choupani, Roya; Tolun, Mehmet R. (2005). "Hand gesture recognition in variable length sequences", WSEAS Transactions on Information Science and Applications, Vol. 2, No. 9, pp. 1294-1301.
Hand gesture recognition in variable length sequences
(2005) Choupani, Roya; Tolun, Mehmet R.; 1863
Using hand gestures in human computer interaction has been a major challenge during the recent years. Many of the hand gesture recognition systems however, have been based on the recognition of hand postures and estimating the related gesture which is restricted to a few numbers of possible movements. However when dealing with applications such as understanding sign languages which include a large number of classes, an automatic learning method based on matching a sequence of postures with the characterizing feature sequence of each class is necessary. An important characteristic of this method is that each sample sequence of a class may have a variable length and different position of the key features. In this paper a syntactic method has been proposed for classifying the input sequences. An algorithm foe extracting the grammar of the method during training stage is also given.
Citation Count: Sahin, S.; Tolun, M. R.; Hassanpour, R. "Hybrid expert systems: A survey of current approaches and applications", Expert Systems With Applications, Vol. 39, No. 4, pp. 4609-4617, (2012)
Hybrid Expert Systems: A Survey of Current Approaches and Applications
(Expert Systems With Applications, 2012) Şahin, S.; Tolun, Mehmet R.; Hassanpour, Reza; 1863
This paper is a statistical analysis of hybrid expert system approaches and their applications but more specifically connectionist and neuro-fuzzy system oriented articles are considered. The current survey of hybrid expert systems is based on the classification of articles from 1988 to 2010. Present analysis includes 91 articles from related academic journals, conference proceedings and literature reviews. Our results show an increase in the number of recent publications which is an indication of gaining popularity on the part of hybrid expert systems. This increase in the articles is mainly in neuro-fuzzy and rough neural expert systems' areas. We also observe that many new industrial applications are developed using hybrid expert systems recently. (C) 2011 Elsevier Ltd. All rights reserved.
Citation Count: Yıldırım, Pınar; Tolun, Mehmet R., "Induction for radiology patients", Electronic Healthcare, Vol.1, pp.208-220, (2009).
Induction for radiology patients
(Springer, 2009) Yıldırım, Pınar; Tolun, Mehmet R.; 101956
This paper represents the implementation of an inductive learning algorithm for patients of Radiology Department in Hacettepe University hospitals to discover the relationship between patient demo-graphics information and time that patients spend during a specific radiology exam. ILA has been used for the implementation which generates rules and the results are evaluated by evaluation metrics. According to generated rules, some patients in different age groups or birthplaces may spend more time for the same radiology exam than the others.
Citation Count: Choupani, Roya; Tolun, Mehmet R. (2007). "Main issues in scalable video coding: A review", Proceedings of the 2007 International Conference on Image Processing, Computer Vision, and Pattern Recognition, IPCV 2007, 2007 International Conference on Image Processing, Computer Vision, and Pattern Recognition, IPCV 2007; 25 June 2007 through 28 June 2007pp. 497-505.
Main issues in scalable video coding: A review
(2007) Choupani, Roya; Tolun, Mehmet R.
Video streaming over the Internet has gained popularity during the recent years which is mainly the result of the introduction of videoconferencing and videotele-phony. These in turn have made it possible to bring to life many applications such as transmitting video over the Internet and over telephone lines, surveillance and monitoring, telemedicine (medical consultation and diagnosis at a distance), and computer based training and education. The heterogeneous, dynamic and best-effort structure of the Internet however, can not guarantee any specific bandwidth for a connection. Many video coding standards have tried to deal with this problem by introducing the scalability feature as adapting video streams to the fluctuations in the available bandwidths. In this review, we have discussed the main technical features of more common scalable video coding techniques. The main problems of these methods and their applicability together with the available motion compensated video coding methods are discussed as well.
Citation Count: Yildirim, Pinar...et al. "Mining Medline for the Treatment of Osteoporosis", Journal of Medical Systems, Vol. 36, No. 4, pp. 2339-2347, (2012)
Mining Medlıne for the Treatment of Osteoporosis
(Springer, 2012) Yıldırım, Pınar; Çeken, Çınar; Hassanpour, Reza; Esmelioğlu, Sadık; Tolun, Mehmet R.; 101956
In this paper, we consider the importance of osteoporosis disease in terms of medical research and pharmaceutical industry and we introduce a knowledge discovery approach regarding the treatment of osteoporosis from a historical perspective. Osteoporosis is a systemic skeletal disease in which osteoporotic fractures are associated with substantial morbidity and mortality and impaired quality of life. Osteoporosis has also higher costs, for example, longer hospital stays than many other diseases such as diabetes and heart attack and it is an attractive market for pharmaceutical companies. We use a freely available biomedical search engine leveraging text-mining technology to extract the drug names used in the treatment of osteoporosis from MEDLINE articles. We conclude that alendronate (Fosamax) and raloxifene (Evista) have the highest number of articles in MEDLINE and seem the dominating drugs for the treatment of osteoporosis in the last decade.
Citation Count: Choupani, Roya; Wong, Stephan; Tolun, Mehmet R., "Multiple description coding for SNR scalable video transmission over unreliable networks", Multimedia Tools And Applications, Vol69, No.3, pp.843-858, (2014).
Multiple description coding for SNR scalable video transmission over unreliable networks
(Springer, 2014) Choupani, Roya; Wong, Stephan; Tolun, Mehmet R.
Streaming multimedia data on best-effort networks such as the Internet requires measures against bandwidth fluctuations and frame loss. Multiple Description Coding (MDC) methods are used to overcome the jitter and delay problems arising from frame losses by making the transmitted data more error resilient. Meanwhile, varying characteristics of receiving devices require adaptation of video data. Data transmission in multiple descriptions provides the feasibility of receiving it partially and hence having a scalable and adaptive video. In this paper, a new method based on integrating MDC and signal-to-noise ratio (SNR) scalable video coding algorithms is proposed. Our method introduces a transform on data to permit transmitting them using independent descriptions. Our results indicate that on average 1.71dB reduction in terms of Y-PSNR occurs if only one description is received.
Citation Count: Choupani, Roya; Wong, Stephan; Tolun, Mehmet R. "Multiple Description Scalable Coding for Video Transmission over Unreliable Networks", Embedded Computer Systems: Architectures, Modeling, and Simulation, pp. 58-67, 2009.
Multiple Description Scalable Coding for Video Transmission over Unreliable Networks
(2009) Choupani, Roya; Wong, Stephan; Tolun, Mehmet R.; 1863
Developing real time multimedia applications for best effort networks such as the Internet requires prohibitions against jitter delay and frame loss. This problem is further complicated in wireless networks as the rate of frame corruption or loss is higher in wireless networks while they generally have lower data rates compared to wired networks. On the other hand, variations of the bandwidth and the receiving device characteristics require data rate adaptation capability of the coding method. Multiple Description Coding (MDC) methods are used to solve the jitter delay and frame loss problems by making the transmitted data more error resilient, however, this results in reduced data rate because of the added overhead. MDC methods do not address the bandwidth variation and receiver characteristics differences. In this paper a new method based on integrating MDC and the scalable video coding extension of H.264 standard is proposed. Our method can handle both jitter delay and frame loss, and data rate adaptation problems. Our method utilizes motion compensating scheme and, therefore, is compatible with the current video coding standards such as MPEG-4 and H.264. Based on the simulated network conditions, our method shows promising results and we have achieved up to 36dB for average Y-PSNR.
Citation Count: Uludağ, M., Tolun, M.R. (2006). A new relational learning system using novel rule selection strategies. Knowledge-Based Systems, 19(8), 765-771. http://dx.doi.org/10.1016/j.knosys.2006.05.004
A New Relational Learning System Using Novel Rule Selection Strategies
(Elsevier Science, 2006) Uludağ, Mahmut; Tolun, Mehmet R.
This paper describes a new rule induction system, rila, which can extract frequent patterns from multiple connected relations. The system supports two different rule selection strategies, namely the select early and select late strategies. Pruning heuristics are used to control the number of hypotheses generated during the learning process. Experimental results are provided on the mutagenesis and the segmentation data sets. The present rule induction algorithm is also compared to the similar relational learning algorithms. Results show that the algorithm is comparable to similar algorithms
Citation Count: Yildirim, Pinar...et al. "Prediction of Similarities Among Rheumatic Diseases", Journal Of Medıcal Systems, Vol. 36, No. 3, pp. 1485-1490, (2012)
Prediction Of Similarities Among Rheumatic Diseases
(Springer, 2012) Yıldırım, Pınar; Çeken, Çınar; Hassanpour, Reza; Tolun, Mehmet R.; 101956
We introduce a method for extracting hidden patterns seen in rheumatic diseases by using articles from the widely used biomedical database MEDLINE. Rheumatic diseases affect hundreds of millions of people worldwide and lead to substantial loss of functioning and mobility. Diagnosing rheumatic diseases can be difficult because some symptoms are common to many of them. We use Facta system as a biomedical text mining tool for finding symptoms and then create a dataset with the frequencies of symptoms for each disease and apply hierarchical clustering analysis to find similarities between diseases. Clustering analysis yields four distinct types or groups of rheumatic diseases. Although our results cannot remove all the uncertainty for the diagnosis of rheumatic diseases, we believe they can contribute to the diagnosis of rheumatic diseases to a certain extent. We hope that some similarities exposed can provide additional information at the stage of decision-making.
Citation Count: Tolun, Mehmet R.; Sever, Hayri; Görür, A.Kadir, "Production and retrieval off rough classes in multi relations", GRC: 2007 IEEE International Conference On Granular Computing, Proceedings, pp. 192-198, (2007).
Production and retrieval off rough classes in multi relations
(IEEE Computer Soc, 2007) Tolun, Mehmet R.; Sever, Hayri; Görür, Abdül Kadir; 11916; 107251
Organizational memory in today's business world forms basis for organizational learning, which is the ability of an organization to gain insight and understanding from experience through experimentation, observation, analysis, and a willingness to examine both successes and failures. This basically requires consideration of different aspects of knowledge that may reside on top of a conventional information management system. Of them, representation, retrieval and production issues of meta patterns constitute to the main theme of this article. Particularly we are interested in a formal approach to handle rough concepts. We utilize rough classifiers to propose a preliminary framework based on minimal term sets with p-norms to extract meta patterns. We describe a relational rule induction approach, which is called rila. Experimental results are provided on the mutagenesis, and the KDD Cup 2001 genes data sets.
Citation Count: Choupani, Roya; Tolun, Mehmet R. (2006). "Recent challenges in video coding and streaming", International Conference on Signals and Electronic Systems, ICSES'0617 September 2006through 20 September 2006, pp. 157-160.
Recent challenges in video coding and streaming
(2006) Choupani, Roya; Tolun, Mehmet R.; 1863
Video streaming over the Internet has gained popularity during the recent years which is mainly the result of the introduction of video-conferencing and videotelephony. These in turn have made it possible to bring to life many applications such as transmitting video over the Internet and telephone lines, surveillance and monitoring, telemedicine (medical consultation and diagnosis at a distance), and computer based training and education. These applications need a large bandwidth which is not available in all cases. Many video encoding standards have been introduced to deal with video compression and transmission problems. In this study, we have discussed the main technical features of the most important video coding standards in a comparative approach. The appropriateness of these features is application and transmission environment dependant. Manipulating video stream features or video transcoding methods are discussed as well.
Citation Count: Choupani, Roya; Wong, Stephan; Tolun, Mehmet, "Unbalanced multiple description wavelet coding for scalable video transmission", Journal of Electronic Imaging, Vol. 21, No. 4, (2012)
Unbalanced Multiple Description Wavelet Coding for Scalable Video Transmission
(IS&T & SPIE, 2012) Choupani, Roya; Wong, Stephan; Tolun, Mehmet R.; 21259
Scalable video coding and multiple description coding are the two different adaptation schemes for video transmission over heterogeneous and best-effort networks such as the Internet. We propose a new method to encode video for unreliable networks with rate adaptation capability. Our proposed method groups three dimensional discrete wavelet transform coefficients in different descriptions and applies a modified embedded zero tree data for rate adaptation. The proposed method optimizes the bit-rates of the descriptions with respect to the channel bit rates and the maximum acceptable distortion. The experimental results in the presence of one description loss indicate that on average the videos at the rate of 1000 Kbit/s are reconstructed with Y-component of peak signal to noise ratio (Y-PSNR) value of 36.2 dB. The dynamic allocation of descriptions to the network channels is optimized for rate distortion minimization. The improvement in term of Y-PSNR achieved by rate distortion optimization has been between 0.7 and 5.3 dB in different bit rates. (c) 2012 SPIE and IS&T. [DOI: 10.1117/1.JEI.21.4.043006]
Citation Count: Choupani, Roya; Wong, Stephan; Tolun, Mehmet R. (2008). "Weighted embedded zero tree for scalable video compression", Proceedings of the 2008 International Conference on Image Processing, Computer Vision, and Pattern Recognition, IPCV 2008, 14 July 2008 through 17 July 2008, pp. 681 - 684.
Weighted embedded zero tree for scalable video compression
(2008) Choupani, Roya; Wong, Stephan; Tolun, Mehmet R.
Video streaming over the Internet has gained popularity during recent years mainly due to the revival of videoconferencing and videotelephony applications and the proliferation of (video) content providers. However, the heterogeneous, dynamic, and best-effort nature of the Internet cannot always guarantee a certain bandwidth for an application utilizing the Internet. Scalability has been introduced to deal with such issues (up to a certain point) by intelligently separating any information stream into multiple streams. The reception of one, several, or all stream influences the perceived quality of the information as basic, improved, or best, respectively. In addition, wavelet-based scalability combined with representation methods such as embedded zero trees (EZWs) improves the decode-ability of the stream even when only the initial part of the streams have been received. In this paper, we propose a method to improve on the compression rate of the EZW for scalability purposes by reducing the number of levels used in the tree. Therefore, the proposed method should be able to deal more efficiently with the mentioned scalability issues in low bandwidth network. Initial experimental show that the first two layers of the generated EZW are about 22.6% more concise.
Citation Count: FİDANBOY, C.Ö., TOLUN, M.R., (2010). Yazılım süreç iyileştirmede CASE aracı kullanımının CMMI süreç yönetimi kategorisi açısından değerlendirilmesi, Cankaya University Journal of Science and Engineering, Volume 7 (2010), No. 2, pp.115–128
Yazılım süreç iyileştirmede CASE aracı kullanımının CMMI süreç yönetimi kategorisi açısından değerlendirilmesi
(Çankaya Üniversitesi, 2010) Fidanboy, Cemalettin Öcal; Tolun, Mehmet R.; 1863
Yazılım mühendisliğinin bilgi alanlarından biri olan yazılım kalitesinin belirlenmesi için temel oluşturan model ve standartlar her geçen gün değer kazanmaktadır. Yazılım kalitesini belirleyen temel unsurlar; yazılım süreçlerinin kuruluş ihtiyaçlarına uygun olarak belirlenmesi, yönetilmesi ve sistematik olarak iyileştirilmesidir. Uluslararası yazılım süreç iyileştirme model ve standartları temel alındığında, yazılım geliştirme projelerinin yüksek kalite düzeylerine ulaşması, projelerin istenen sürede ve en uygun maliyette tamamlanması mümkün olmaktadır. Bütünleşik Yetenek Olgunluk Modeli (CMMI), yazılım geliştirme, bakım ve süreç iyileştirme konularında, en iyi yönetim uygulamalarının birleştirilmesi sonucu oluşturulan önemli modellerden birisidir. Yazılım süreç iyileştirme, çalışmalarında CASE (bilgisayar destekli yazılım mühendisliği) araçlarının kullanılması; süreç iyileştirme sisteminin verimli bir şekilde kurgulanması, etkin bir konfigürasyon yönetiminin sağlanması ve sağlam bir metrik altyapısının kurulması açısından önemli faydalar sağlamaktadır. Bu makalede, öncelikli olarak CMMI Süreç Yönetimi kategorisinde yer alan ve kurumsal süreç iyileştirme uygulamalarını hedefleyen Kurumsal Süreç Tanımı ile Kurumsal Süreç Odaklanması Süreç alanları tanıtılmaktadır. Aynı zamanda, CMMI Süreç Yönetimi kategorisi kapsamında CASE aracı kullanımına yönelik örnekler verilmektedir. Ek olarak, CASE aracı kullanımının yazılım süreç iyileştirme uygulamalarına etkisini ortaya çıkarmak üzere yapılan bir kullanıcı anketine ilişkin sonuçlar sunulmakta ve bahsi geçen konularda CMMI modeli açısından değerlendirme yapılmaktadır.