I. Defee

Tampere University of Technology, Tammerfors, Province of Western Finland, Finland

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Publications (59)14.43 Total impact

  • Source
    Florin Lohan, Irek Defee
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    ABSTRACT: In this paper we present a web-based management system that is capable to configure, control and monitor several types of multimedia servers. The implementation of the management system currently supports three types of servers: DVB over IP servers, VoD servers and MPEG-2 Transcoders. We give details about the initial requirement, how the system was designed to fulfill these requirements, and about the implementation aspects.
    01/2011;
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    ABSTRACT: Notification is a service that addresses devices and users with messages to be processed immediately or at a specific time. Notification is important for delivering emergency, warning, and other timely messages. In this article extensions to include notification service in the data transport system called IP DataCast used in the DVB-H mobile television standard are presented. The architecture of IPDC in DVB-H is first overviewed, and the notification service elements complementing it are described. Next, the notification protocols and message formats are defined, and the system operation is explained. The presented notification system is now part of the new IPDC over DVB-H standard.
    IEEE Wireless Communications 05/2010; · 3.74 Impact Factor
  • Irek Defée
    Signal Image and Video Processing 01/2010; 4(4). · 1.02 Impact Factor
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    ABSTRACT: Wireless sensor networks have significant potential in the home environment. Home application scenarios include monitoring and interaction from several remote or local devices such as mobile phones, televisions or computers. In this paper we propose an architecture for a network based on IP-enabled wireless sensors. The communication system is based on the XMPP-protocol which is shown to be highly suitable for the sensor networks. XMPP provides a push based notification functionality that is especially appropriate for the event-driven paradigm of sensors and also provides the authentication and encryption required for data protection. We also use Atom feeds together with XMPP to enable remote web service-like access to the wireless sensor network. Integration of this XMPP-based wireless sensor network with the standard UPnP media-oriented network is done using a XMPP to UPnP gateway. In this paper, home applications and services are first introduced and different technologies supporting them are described. Next, the benefits of XMPP/IP architecture compared to non-IP sensor networks and to the UPnP based sensor network are discussed. We then present our XMPP-based wireless sensor network, with web-service like access, using XMPP and Atom feeds, also interfacing with UPnP. These solutions have been implemented on internet tablet devices allowing a flexible, highly functional and open system for integrating sensor network with the media environment.
    Consumer Electronics, 2009. ISCE '09. IEEE 13th International Symposium on; 06/2009
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    ABSTRACT: The health care costs in developed countries are increasing fast due to the aging of the population. In-home monitoring of health is becoming more and more attractive both because of expected cost-savings and technical development of suitable measurement devices and wireless sensor networks. In this paper, we present on-going work about embedding health monitoring devices into ordinary homes. The developed system is targeted both for monitoring elderly and for monitoring rehabilitation after hospitalization period. The paper presents the utilized sensor network implementation, chosen set of sensors for the first test trial, as well as other design choices for the trial. In addition, further objectives about concentrating on one special case, the ubiquitous heart rate measurement, are discussed. Our objective is to install several non-contact heart rate monitors into a home environment. The designed system performed well during the trial. However, some issues, such as sensor addressing in WSN and user identification, will be better taken into account in the next trials.
    IEEE Fourth International Symposium on Industrial Embedded Systems - SIES 2009, Ecole Polytechnique Federale de Lausanne, Switzerland, July 8 - 10, 2009; 01/2009
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    ABSTRACT: The proliferation of mobile broadcast networks and home multimedia networks makes relevant considering a new level of digital convergence. One aspect is the integration of mobile content access to the home network. In this framework, a mobile device serves as a gateway for real time content rebroadcast. This paper investigates the mobile rebroadcasting problem and implementation between the Mobile TV system based on the DVB-H standard and DLNA/UPnP enabled home network based on WLAN.
    IEEE Transactions on Consumer Electronics 09/2008; · 1.09 Impact Factor
  • A. Hornsby, I. Bouazizi, I. Defee
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    ABSTRACT: Notification is a service which addresses devices and users with messages or applications to be executed immediately or at specific time. Notification is important for delivering emergency, warnings and other timed messages. Recently introduced mobile broadcast is an ideal candidate for notification services due to its constant availability and potential for simultaneous addressing of very large user groups. Mobile devices also have connectivity to non-broadcast networks which allows for extended notification relying on user interaction, bringing its scope to applications requiring a response mechanism, e.g. for voting. In this paper, extensions to include notification service into the data transport system called IP Datacast (IPDC) used in the DVB-H mobile television standard are presented. The notion of notification services is first overviewed and the notification service elements complementing IPDC in DVB-H are described. Next the notification protocols and message formats are defined and the default notification channels are explained. The presented notification system reflects the current standardization status within the DVB and introduces extensions and new functionalities.
    Consumer Electronics, 2008. ISCE 2008. IEEE International Symposium on; 05/2008
  • M. Oksanen, I. Defee
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    ABSTRACT: DVB-H is a standardized technique for broadcasting dasiaTV likepsila content to mobile devices. As the technology is at early deployment stage, various techniques to improve performance are being developed and evaluated. Concerning this novel technology, not only the quality of reception but also the quality of services and their content has to be considered. Full DVB-H transmit diversity test bed in the Tampere University of Technology is employed for creating mobile services and evaluating transmit diversity techniques. In this paper, we describe the measurement campaign planned to analyze the impacts of transmit diversity on mobile reception. Various reception environments and service scenarios are evaluated in the campaign and results are presented.
    Consumer Electronics, 2008. ISCE 2008. IEEE International Symposium on; 05/2008
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    ABSTRACT: The proliferation of mobile broadcast networks and home multimedia networks makes relevant considering a new level of digital convergence. One aspect is the integration of mobile content access to the home network. In this framework, a mobile device serves as a gateway for real time content rebroadcast. This paper investigates the mobile rebroadcasting problem and implementation between the Mobile TV system based on the DVB-H standard and DLNA/UPnP enabled home network based on WLAN.
    Consumer Electronics, 2008. ICCE 2008. Digest of Technical Papers. International Conference on; 02/2008
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    ABSTRACT: This paper presents a home sensor network for wireless health monitoring, including a wireless sensor network, client for controlling the sensor network, and a data storage server. A common software and hardware microcontroller-sensor interface was defined to enable joint use of sensor technologies developed in three different projects. IEEE 802.15.4 RF-transceiver based radio-boards and ZigBee network software were designed and built, along with a simple sensor network software on top of the ZigBee stack, to implement the wireless sensor network. Both commercial and custom made sensors have been interfaced to the sensor network. A set-up consisting of four sensors was developed and tested in a real home environment. The architectural overview of the system and main technical design choices are presented.
    International Conference on Biocomputation, Bioinformatics, and Biomedical Technologies, BIOTECHNO 2008, June 29 - July 5, 2008, Bucharest, Romania; 01/2008
  • Source
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    ABSTRACT: Recently, DVB-H mobile television standard was completed and has now entered the deployment stage. Being an IP-based broadcast network, DVB-H contributes to providing multimedia experience for mobile TV users. However, they are still big challenges to face because of the strict "anytime, anywhere" user's expectation. For example, when the mobile receiver is located near to the border of the coverage area, inside building or in obscure zones, the user is still expecting to receive the selected service without an interrupt. Being so widely deployed and relatively cheap, Wi-Fi is a very good candidate to provide the extra coverage required to DVB-H network. This paper presents an AHP based network selection system enabling mobile device to execute handover between DVB-H and Wi-Fi network. We have successfully simulated and tested our approach and we are able to handover between the two technologies while maintaining constant service connectivity, thus improving user experience.
    Broadband Multimedia Systems and Broadcasting, 2008 IEEE International Symposium on; 01/2008
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    Daidi Zhong, Irek Defée
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    ABSTRACT: A framework for the unification of statistical and structural information for pattern retrieval based on local feature sets is pre-sented. We use local features constructed from coefficients of quantized block transforms borrowed from video compression which robustly preserving perceptual information under quantization. We then describe statistical information of patterns by histograms of the local features treated as vectors and similarity measure. We show how a pattern retrieval system based on the feature histograms can be optimized in a training process for the best performance. Next, we incorporate structural information description for patterns by considering decomposition of patterns into subareas and considering their feature histograms and their combinations by vectors and similarity measure for retrieval. This description of patterns allows flexible varying of the amount of statistical and structural information; it can also be used with training process to optimize the retrieval performance. The novelty of the presented method is in the integration of information contributed by local features, by statistics of feature distribution, and by controlled inclusion of structural information which are combined into a retrieval system whose parameters at all levels can be adjusted by training which selects contribution of each type of information best for the overall retrieval performance. The pro-posed framework is investigated in experiments using face databases for which standardized test sets and evaluation procedures exist. Results obtained are compared to other methods and shown to be better than for most other approaches.
    Journal on Advances in Signal Processing 01/2008; 2008. · 0.81 Impact Factor
  • Source
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    ABSTRACT: In this paper a method for providing additional information for error concealment during the transmission of a video file over an error-prone channel is presented. The transmission of the additional information is performed without increasing the bandwidth occupation, by hiding this information into the video itself at the encoder side. The considered transmission system is the DVB-H system. The performance of the method has been investigated by simulations and experimental tests in order to evaluate the perceived quality of the processed video and the robustness of the data hiding method against the H.264/AVC coding.
    Multimedia Signal Processing, 2007. MMSP 2007. IEEE 9th Workshop on; 11/2007
  • Daidi Zhong, I. Defee
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    ABSTRACT: Patterns are characterized by the distribution of features. In general detailed geometry of feature locations and statistics of features distribution are important for the characterization. We call these aspects structural and statistical information of patterns and aim for developing framework for the unified description of them. Statistical information can be simply and conveniently picked by feature histograms, structural information description is much more complex. In order to deal with it we are introducing the concept of hierarchical decomposition of pattern areas. Areas are described using statistical information by feature histograms, size and number of areas reflects structural information. This formulation unifies statistical and structural information and the problem of minimizing structural information is stated as reducing the number and size of the histograms. We illustrate this on an example of retrieval from face image database using features based on quantized block transform coefficients. We can show that very limited structural information is needed for nearly perfect retrieval performance equal to the best available algorithms.
    Machine Learning for Signal Processing, 2007 IEEE Workshop on; 09/2007
  • A.J. Hornsby, I. Defee
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    ABSTRACT: This paper concerns network and service discovery problems in heterogeneous broadcast environment. Broadcasting has traditionally been limited to single network type. The future broadcasting landscape will be composed of different type of networks, especially the mobile broadcast networks like DVB-H, DMB, WLAN, WiMAX and 3G MBMS. Integration of these networks into a unified broadcast infrastructure requires extensions to the current network and service discovery methods. Existing methods are limited to a single network type which makes them cumbersome. There is a possibility to considerably improve this process by unifying the network and service discovery across different broadcast networks. The process can also be helped by utilizing location databases. In this paper, we propose a Universal Network and Service Discovery (UNSD) system and positioning information system which provides discovery support for many different network types and inclusion of positioning information.
    Mobile and Wireless Communications Summit, 2007. 16th IST; 08/2007
  • Source
    M. Armholt, S. Junnila, I. Defee
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    ABSTRACT: In this paper we present our implementation of a layered ZigBee network and the performance test results using non-beaconing networks. Adding the implemented network layer to an existing IEEE 802.15.4 stack did not affect the throughput in the network. It is also concluded that with knowledge of the network structure an extra added delay between sending packets can reduce the number of packets lost due to channel access failure without decrease in throughput.
    Communications, 2007. ICC '07. IEEE International Conference on; 07/2007
  • Daidi Zhong, Irek Defée
    SIGMAP 2007 - Proceedings of the Second International Conference on Signal Processing and Multimedia Applications, Barcelona, Spain, July 28-31, 2007, SIGMAP is part of ICETE - The International Joint Conference on e-Business and Telecommunications; 01/2007
  • Daidi Zhong, Irek Defée
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    ABSTRACT: We investigate similarity measures for image retrieval from databases based on histograms of local feature vectors. The feature vectors are obtained from grouping quantized block transforms coefficients and thresholding. After preliminaries on block transforms we are introducing binary DC and AC feature vectors. Subsequently ternary DC and AC vectors are defined. Next we show how the histograms of vectors defined can be combined to form similarity measure for image retrieval from database. We formulate the database training and retrieval problem using the defined similarity measures. Performance results are shown using widely used FERET and ORL databases and the cumulative match score evaluation. We show that despite simplicity the proposed measures provide results which are on par with best results using other methods. This indicates that statistics based retrieval should not be underestimated comparing to structural methods.
    Pattern Recognition Letters. 01/2007; 28:2003-2010.
  • Daidi Zhong, Irek Defée
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    ABSTRACT: Face image can be seen as a complex visual object, which combines a set of characterizing facial features. These facial features are crucial hints for machine to distinguish different face images. However, the face image also contains certain amount of redundant information which can not contribute to the face image retrieval task. Therefore, in this paper we propose a retrieval system which is aim to eliminate such effect at three different levels. The Ternary Feature Vector (TFV) is generated from quantized block transform coefficients. Histograms based on TFV are formed from certain subimages. Through this way, irrelevant information is gradually removed, and the structural and statistical information are combined. We testified our ideas over the public face database FERET with the Cumulative Match Score evaluation. We show that proper selection of subimage and feature vectors can significantly improve the performance with minimized complexity. Despite of the simplicity, the proposed measures provide results which are on par with best results using other methods.
    Advances in Visual Information Systems, 9th International Conference, VISUAL 2007, Shanghai, China, June 28-29, 2007 Revised Selected Papers; 01/2007
  • Source
    Daidi Zhong, Irek Defée
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    ABSTRACT: We consider the use of quantized block transform coeffi-cients to the image database retrieval problem. Based on the transform coefficients feature vectors are constructed. These feature vectors are used in histograms and combination of histograms with similarity measure for database retrieval. Experiments on public face image database show good per-formance of the approach in comparison with other methods.
    01/2007;

Publication Stats

113 Citations
14.43 Total Impact Points

Institutions

  • 1997–2011
    • Tampere University of Technology
      • • Department of Signal Processing
      • • Department of Electrical Energy Engineering
      Tammerfors, Province of Western Finland, Finland
  • 2008
    • Nokia Research Center (NRC)
      Helsinki, Southern Finland Province, Finland
  • 2007
    • Università Degli Studi Roma Tre
      • Department of Applied Electronics
      Roma, Latium, Italy