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Now showing 1 - 7 of 7
  • Conference Object
    Citation - Scopus: 1
    Performance Evaluation of Self Organizing Neural Networks for Clustering in Esm Systems;
    (IEEE Computer Society, 2014) Gencol,K.; Tora,H.
    Electronic Support Measures (ESM) system is an important function of electronic warfare which provides the real time projection of radar activities. Such systems may encounter with very high density pulse sequences and it is the main task of an ESM system to deinterleave these mixed pulse trains with high accuracy and minimum computation time. These systems heavily depend on time of arrival analysis and need efficient clustering algorithms to assist deinterleaving process in modern evolving environments. On the other hand, self organizing neural networks stand very promising for this type of radar pulse clustering. In this study, performances of self organizing neural networks that meet such clustering criteria are evaluated in detail and the results are presented. © 2014 IEEE.
  • Conference Object
    Citation - Scopus: 2
    The Use of Cumulants for Voiced-Unvoiced Segments Identification in Speech Signals;
    (IEEE Computer Society, 2014) Uslu,B.; Tora,H.
    In 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. © 2014 IEEE.
  • Conference Object
    Citation - Scopus: 7
    Two-way/Hybrid Clustering Architecture for Peer To Peer Systems
    (IEEE Computer Society, 2007) Öztoprak,K.; Akar,G.B.
    In this paper, we propose a novel hybrid topology and interest based clustering to organize the overlay network in order to reduce startup latency and service interruption probability. Our method uses a clustering technique to organize the peers according to their interests and locality information. The proposed technique is compared with the current unstructured P2P architectures in terms of average hit time, hit ratio for searched content, and the maximum rate of information (in bits per second) that can be transmitted over P2P network caused by protocol and overlay-level connectivity. The simulation results show that the proposed system outperforms the current unstructured P2P architectures. © 2007 IEEE.
  • Conference Object
    Citation - Scopus: 1
    Higher Order Statistical Analysis of Turkish Phones;
    (IEEE Computer Society, 2014) Tora,H.; Uslu,B.
    In 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.
  • Conference Object
    Citation - Scopus: 2
    On the Decidability of Shared Memory Consistency Verification
    (IEEE Computer Society, 2005) Sezgin,A.; Gopalakrishnan,G.
    We view shared memories as structures which define relations over the set of programs and their executions. An implementation is modeled by a transducer, where the relation it realizes is its language. This approach allows us to cast shared memory verification as language inclusion. We show that a specification can be approximated by an infinite hierarchy of finite-state transducers, called the memory model machines. Also, checking whether an execution is generated by a sequentially consistent memory is approached through a constraint satisfaction formulation. It is proved that if a memory implementation generates a non interleaved sequential and unambiguous execution, it necessarily generates one such execution of bounded size. Our paper summarizes the key results from the first author's dissertation, and may help a practitioner understand with clarity what "sequential consistency checking is undecidable" means. © 2005 IEEE.
  • Conference Object
    Citation - Scopus: 14
    An indoor navigation aid designed for visually impaired people
    (IEEE Computer Society, 2008) Öktem,R.; Aydin,E.; Çaǧiltay,N.E.
    This work introduces the hardware architecture and general principles of a portable indoor navigation system for guiding visually impaired people. It operates through wireless communication between a compact hardware interface unit carried by the user, a central processing unit and an active RFID unit. The RFID unit collects signals as regard to the position of the user, the central system processes those signals to estimate the position of the user and proposes a route and direction for the user to follow, whereas hardware interface unit provides interaction. The orienteering of the user is obtained by a tactile compass. © 2008 IEEE.
  • Conference Object
    On the decidability of shared memory consistency verification
    (IEEE Computer Society, 2005) Sezgin,A.; Gopalakrishnan,G.
    We view shared memories as structures which define relations over the set of programs and their executions. An implementation is modeled by a transducer, where the relation it realizes is its language. This approach allows us to cast shared memory verification as language inclusion. We show that a specification can be approximated by an infinite hierarchy of finite-state transducers, called the memory model machines. Also, checking whether an execution is generated by a sequentially consistent memory is approached through a constraint satisfaction formulation. It is proved that if a memory implementation generates a non interleaved sequential and unambiguous execution, it necessarily generates one such execution of bounded size. Our paper summarizes the key results from the first author's dissertation, and may help a practitioner understand with clarity what "sequential consistency checking is undecidable" means. © 2005 IEEE.