Lidé

Ing. Jan Kubr, Ph.D.

Všechny publikace

Optimization of Distributed Phase Shift Beamforming Configuration by using Convex Hull

  • Autoři: Ing. Jan Kubr, Ph.D., Černý, V., Moucha, A.
  • Publikace: 2020 10th International Conference on Advanced Computer Information Technologies, ACIT 2020 - Proceedings. IEEE Xplore, 2020. p. 273-277. vol. 10. ISBN 978-1-7281-6760-2.
  • Rok: 2020
  • DOI: 10.1109/ACIT49673.2020.9208818
  • Odkaz: https://doi.org/10.1109/ACIT49673.2020.9208818
  • Pracoviště: Katedra počítačové grafiky a interakce
  • Anotace:
    This article deals with a problem of disconnected wireless sensor networks. Our team investigates a usage of distributed or collaborative beamforming for creation of new long-distance connections between loose network clusters. We focus on decreasing the complexity of searching for network modules which are suitable for creation of inter-cluster connection using distributed/collaborative beamforming techniques.

Distributed phase-shift beamforming power balancing in ad-hoc and sensor networks

  • Autoři: Moucha, A., Černý, V., Ing. Jan Kubr, Ph.D., Janeček, J.
  • Publikace: Telecommunication Systems. 2014, 57(4), 367-377. ISSN 1018-4864.
  • Rok: 2014
  • DOI: 10.1007/s11235-013-9839-2
  • Odkaz: https://doi.org/10.1007/s11235-013-9839-2
  • Pracoviště: Katedra počítačů
  • Anotace:
    Ad-hoc and sensor networks are a well-studied area which gained a lot of attention in the research in the last decades. Two of the problems of battery-powered radio devices are limited transmitter power and finite amount of energy. This paper continues the path opened by the development of a new technology for radio communication which allows cluster communication beyond the horizon of each individual transmitter and the distribution of power need among the modules forming a cluster. This in terms decreases the average power need per device and contributes to a longer lifetime of the entire network.

Interference Cancellation by the Usage of Distributed Phase Shift Beamforming

  • Autoři: Černý, V., Moucha, A., Ing. Jan Kubr, Ph.D.,
  • Publikace: 2014 Eighth International Conference on Next Generation Mobile Applications, Services and Technologies. Los Alamitos: Conference publishing Services, 2014. p. 248-253. ISBN 978-1-4799-5073-7.
  • Rok: 2014
  • DOI: 10.1109/NGMAST.2014.58
  • Odkaz: https://doi.org/10.1109/NGMAST.2014.58
  • Pracoviště: Katedra počítačů
  • Anotace:
    There are many ways to deal with interference in wireless networks: topology control, scheduling, channel surfing, etc. All try to prevent interference from taking place (by allocating transmissions to different frequencies, to different time slots, etc). The novelty of the proposed approach in this paper is inspired from the way today headphones use noise cancellation – our approach is to use adjacent modules to one transmitter to cancel the signals of that transmitter to desired areas and thus to decrease interference in the network.

Optimal algorithm for phase shift searching for the DPSBF

  • Autoři: Černý, V., Moucha, A., Ing. Jan Kubr, Ph.D.,
  • Publikace: Proceedings of the 2nd Prague Embedded Systems Workshop. 2014. p. 17-21.
  • Rok: 2014
  • Pracoviště: Katedra počítačů
  • Anotace:
    The distributed phase shift beamforming is the great technique for spatial signal filtering in wireless networks. We already showed that this technique can be exploited for the interference reduction in wireless networks. This paper deals with optimal phase shift search for this method.

Advanced Methods for Phase Search in Beamformed Ad-Hoc Wireless Networks

  • Autoři: Ing. Jan Kubr, Ph.D., Černý, V., Moucha, A.
  • Publikace: Proceedings of the 2013 International Conference on Telecommunication Systems, Modeling and Analysis. Dallas, TX: American Telecommunications Systems Management Association Inc., 2013. p. 1-7. ISBN 978-0-9820958-8-1.
  • Rok: 2013
  • Pracoviště: Katedra počítačů
  • Anotace:
    Ad-hoc and sensor networks are a well-studied area, which gained a lot of attention in the research in the last decades. Our team proposed a mechanism which enables wireless networks composed by clusters of modules to be connected even when direct relayed communication be- tween clusters is not possible. A cluster is able to transmit as a virtual transmitter beyond the maximal transmission range of individual mod- ules and is able to balance power needed for the transmission between multiple modules having thus multiple sources of energy. The mecha- nism of distributed or collaborative phase-shift beamforming (CPSBF) has one disadvantage: without a-priori known modules position coordi- nates the discovery phase (in which a cluster discovers its neighbouring clusters) has exponential complexity. In this paper we present certain scenarious which can dramatically reduce this complexity.

Design of the Protocol Stack for the Distributed Phase-Shift Beamforming

  • Autoři: Černý, V., Ing. Jan Kubr, Ph.D.,
  • Publikace: POSTER 2013 - 17th International Student Conference on Electrical Engineering. Prague: Czech Technical University, 2013. ISBN 978-80-01-05242-6.
  • Rok: 2013
  • Pracoviště: Katedra počítačů
  • Anotace:
    Distributed phase-shift beamforming (BF) is a technique which allows long distance communications beyond the maximal range of individual transmitters, by using collaborative transmissions of group of modules. This work is oriented towards the implementation of this mechanism in practice. Thus, several individual transmitters must be synchronized with the help of a protocol or stack of protocols. The main goal of this paper is to find and choose the proper protocol stack model in order to cover all needs of the BF.

ELISA: Extensible Layer for Internet Services and Applications

  • Autoři: Mátl, L., Bohdal, V., Ing. Jan Kubr, Ph.D., Černý, T., Klouček, V.
  • Publikace: POSTER 2013 - 17th International Student Conference on Electrical Engineering. Prague: Czech Technical University, 2013. pp. 1-5. ISBN 978-80-01-05242-6.
  • Rok: 2013
  • Pracoviště: Katedra počítačů
  • Anotace:
    Peer-to-peer systems gain on popularity due to the benefits of decentralization and scalability. Unfortunately it is complex to design such systems because existing frameworks expose low-level functionality, that required deep knowledge of the domain, and rarely provide high-level services for common communication patterns, security, data streaming, while providing self.scalability and resilience towards network changes. In this paper we introduce a peer-to-peer application framework ELISA. It address common issues in peer- to-peer applications development. We present the architecture of the framework together with discussion of its features and functionality. The framework provides multiple strategies to deal with peer-to-peer environment that provides multiple communication patterns, aims to address security concerns and data streaming. Our preliminary performance results received from a network emulation are provided and discussed in this paper.

Mobile Data Network Analysis and Emulation tool

  • Autoři: Ing. Jan Kubr, Ph.D., Ing. Ondřej Votava,
  • Publikace: Proceedings of the 2012 International Conference on Telecommunication Systems, Modeling and Analysis. Dallas, TX: American Telecommunications Systems Management Association Inc., 2012. pp. 128-135. ISBN 978-0-9820958-6-7.
  • Rok: 2012
  • Pracoviště: Katedra počítačů
  • Anotace:
    Smart mobile phones, tablets, notebooks, all these devices require mobile connection to the Internet. Mobile Internet providers promise the great connection parameters and great speeds. The reality often differs and several applications, which require permanent connection to the Internet may not work correctly, which leads to the users' disappointment. The wrong behavior could be fixed in most cases if the programmer tested the application in the specific conditions. We present a tool for analyzing mobile data networks, focused on data transfer, and the emulation tool which is able to emulate the mobile connection on a local network which is a common development environment.

Scheduling of Data Constrained Applications in Distributed Heterogeneous systems

  • Autoři: Ing. Ondřej Votava, Ing. Peter Macejko, Ing. Jan Kubr, Ph.D., Janeček, J.
  • Publikace: Proceedings of the 2012 International Conference on Telecommunication Systems, Modeling and Analysis. Dallas, TX: American Telecommunications Systems Management Association Inc., 2012. pp. 141-149. ISBN 978-0-9820958-6-7.
  • Rok: 2012
  • Pracoviště: Katedra počítačů
  • Anotace:
    Task scheduling is a way of how to run ``any'' application in a distributed computation system. Traditional attitude is loosely coupled with the well known structure of the application and all the data this application needs to work with is already known when the computation begins. Similarly, these data are available to all of the computation nodes. In this article we modified this model by adding constraints that some data are available only after a specific time and at a specific place. We present a modified HEFT, CPOP and DLMDAG algorithms so that they are able to take this modification into account.

Topology Control with High-Gain Sector Turning Antennas in Wireless Networks

  • Autoři: Moucha, A., Černý, V., Ing. Jan Kubr, Ph.D.,
  • Publikace: Proceedings of the 2012 International Conference on Telecommunication Systems, Modeling and Analysis. Dallas, TX: American Telecommunications Systems Management Association Inc., 2012. pp. 160-174. ISBN 978-0-9820958-6-7.
  • Rok: 2012
  • Pracoviště: Katedra počítačů
  • Anotace:
    Topology control (TC) is an important low-level technique that eliminates certain redundant links in ad-hoc and sensor networks, thus allowing easier routing, energy conservation and lower interference. Classic algorithms for TC (RNG, GG, YG, etc.) are based on geometry alone, mimicking the fact that antennas are isotropic (radiate with the same intensity in all directions). This paper studies the case of sector turning antennas, which can be seen as the simplest form of anisotropic antenna, by having only two gains. This paper introduces a new TC algorithm adapted for sector turning antennas, which gives better average interference estimations than both classic (isotropic) and anisotropic TC methods.

Distributed Phase-Shift Beamformed Power Balancing in Ad-Hoc and Sensor Networks

  • Autoři: Moucha, A., Černý, V., Ing. Jan Kubr, Ph.D.,
  • Publikace: Proceedings of the 2011 International Conference on Telecommunication Systems Management. Dallas, TX: American Telecommunications Systems Management Association Inc., 2011. pp. !!!. ISBN 978-0-9820958-4-3.
  • Rok: 2011
  • Pracoviště: Katedra počítačů
  • Anotace:
    Ad-hoc and sensor networks are a well-studied area, which gained a lot of attention in the research in the last decades. Two of the problems of battery- powered radio devices are, due to their small size, limited transmitter power and finite amount of energy. This paper continues the path opened by the development, by our team, of a new technology for radio communication, which allows cluster communication beyond the horizon of each individual transmitter and the distribution of power need among the modules forming a cluster, which in terms decreases the average power need per device and contributes to a longer lifetime of the entire network.

Dynamic Local Scheduling of Multiple DAGs in a Distributed Heterogeneous Systems

  • Autoři: Ing. Ondřej Votava, Ing. Peter Macejko, Ing. Jan Kubr, Ph.D., Janeček, J.
  • Publikace: Proceedings of the 2011 International Conference on Telecommunication Systems Management. Dallas, TX: American Telecommunications Systems Management Association Inc., 2011. pp. 171-178. ISBN 978-0-9820958-4-3.
  • Rok: 2011
  • Pracoviště: Katedra počítačů
  • Anotace:
    Heterogeneous computational platform offers a great ratio between the computational power and the price of the system. Research in static and dynamic scheduling has been done and many algorithms were proposed in the literature. The aim of this article is to present the dynamic (on-line) algorithm which schedules multiple DAG applications dynamically without any central node and the schedule is created only with the local knowledge of the network. This algorithm does not beat the minimal makespan but offers good ratio of fairness for multiple DAGs and usage of computational resources.

Efficiency of Java RMI, Ninja, ARMI and ONC RPC

  • Autoři: Ing. Jan Kubr, Ph.D., Sysala, T.
  • Publikace: Proceedings of Workshop 2001. Praha: České vysoké učení technické v Praze, 2001, pp. 278-279. ISBN 80-01-02335-4.
  • Rok: 2001

Performance Comparison of RPC Communication Protocols

  • Autoři: Ing. Jan Kubr, Ph.D., Janeček, J.
  • Publikace: Workshop 97. Praha: České vysoké učení technické v Praze, 1997. pp. 311-312.
  • Rok: 1997
  • Pracoviště: Katedra počítačů
  • Anotace:
    Přenosový výkon různých komunikačních protokolů

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